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Physics Library
T tº
3, ‘Sº
, ºyº
\º AQ.
U. S. DEPARTMENT OF COMMERCE
JESSE H. JONES, Secretary
NATIONAL BUREAU OF STANDARDS
LYMAN J. BRIGGS, Director
CIRCULAR OF THE NATIONAL BUREAU OF STANDARDS C440
[Supersedes Circular C44]
POLARIMETRY, SACCHARIMETRY
AND THE SUGARS
By
FREDERICK J: BATES and ASSOCIATES
[Issued May 1, 1942]
UNITED STATES
GOVERNMENT PRINTING OFFICE
WASHINGTON : 1942
For sale by the Superintendent of Documents, Washington, D. C. - - - - Price $2,00

PREFACE
This Circular supersedes National Bureau of Standards Circular No.
12, issued July 6, 1906, and Circular No. 44, issued January 15, 1914,
and revised November 1, 1917. The main object of this treatise is to
eaplain the application and manipulation of polarized light for indus-
trial, analytical, and theoretical purposes. The principal application of
polarized light is embodied in the many modifications of the polariscope.
The increasing applications of polarized light to the arts and sciences has
led to a proportionate increase in the requests made to the Bureau for in-
formation. In this Circular an attempt is made to answer as far as
possible such inquiries as well as furnish information of a broader char-
acter and in greater detail than could be given by letter. In order to pre-
sent the necessary explanations, simple physical conceptions and deduc-
tions have been used. Such explanations, however, are not to be construed
or interpreted as an explanation of the physical theory of optical activity.
In spite of the numerous mathematical treatments of this subject in recent
gears, and in spite of the important contributions to the subject of the
structure of naturally optically active compounds from the chemical view-
point, a satisfactory explanation of the phenomenon which comprehends
existing experimental facts is still lacking. The general subjects of mag-
neto and electro optics in relation to polarized light are not discussed, as
they do not come within the province of this treatise.
Van't Hoff and Le Bel discovered how to select from substances of known
chemical structure those substances which produce an angular rotation of
the plane of polarized light. There followed a widespread utilization of
the polariscope in the chemical industries and in chemical research. How-
ever, despite the voluminous researches which resulted and the fact that
physicists have probed deeply into the mature of light in general and polar-
ized light in particular, as well as the nature of the ultimate particles of
which all substances are built up, the mechanism of the interaction be-
tween polarized light and the structure of optically active substances is
still in a state of controversy, as illustrated by the theories of Born, Kuhn,
Boys, and others. No attempt therefore has been made to present a pic-
ture of the present controversial state of the physical theory of the nature
of optical activity. As a justification for the special applications of the
polariscope given in this Circular, it may be stated that carbohydrate
chemistry, and carbohydrate industry dependent upon carbohydrate chem-
istry, could hardly have developed to the magnitude it has attained in
recent years without the aid and guidance of the polariscope. Conversely,
no better insight into the various applications of quantitative measure-
ments with the polariscope can be given than the study of the specific in-
vestigations of carbohydrate chemistry. The application of the polari-
scope in other fields of chemistry, such as essential oils, hydrocarbons,
alkaloids, and other optically active substances, will present no difficulties
to the chemist familiar with its application in carbohydrate chemistry.
Because of this fact, carbohydrate investigations have been given a promi-
ment place in this Circular.
The following members of the staff have collaborated in preparing the
material for this publication: Frederick Bates, N. L. Bowman, D. H.
Brauns, J. F. Brewster, C. S. Cragoe, Harriet L. Frush, P. E. Golden,
L. D. Hammond, Mary L. Hubbell, H. S. Isbell, R. F. Jackson, Emma
J. McDonald, F. P. Phelps, W. W. Pigman, M. J. Proffitt, J. B. Saun-
ders, C. F. Snyder, and A. Q. Tool.
- LYMAN J. BRIGGs, Director.
II
CONTENTS
PART 1. POLARIZED LIGHT, POLARIMETERS, SACCHARIMETERS, AND
ACCESSORY APPARATUS
Preface --------------------------------------------------
I. Introduction----------------------------------------------
II. Polarized light--------------------------------------------
. Nature of polarized light----- - - - - - - - - - - - - - - - - - - - - - • * *
. Inhomogeneity of light and incoherency of light beams
. Composition of rectilinear oscillations having different
Composition of circular Oscillations--- - - - - - - - - - - - - - - - -
. Polarization by double refraction_____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Rotation of the plane of polarization—photogyric
effects------------------------------------------
Circularly polarized component beams in photogyric effects
Polarization of light by reflection - - - - - - - - - - - - - - - - - - - -
Segregation of plane polarized light beams - - - - - - - - - - - -
(a) Polarizers from large crystals - - - - - - - - - - - - - - - -
(b) Polaroid-----------------------------------
(c) Methods of locating the plane of polarization-
10. Production of elliptically polarized light_-______ _ _ _ _ _ _ _
(a) By doubly refracting plates__ _ _ _ _ _ _ _ _ _ _ _ _ _ --- - -
(b) By electric and magnetic fields__ _ _ _ _ _ _ _ _ _ _ _ _ _
11. Measurements on elliptically polarized light _ _ _ _ _ _ _ _ _ _ _
(a) Elliptic polarizers and halfshades_ _ _ _ _ _ _ _ _ _ _ _ _
(b) IJlliptic analyzers------------ - - - - - - - - - - - - - - -
(c) Elliptic compensators. -- - - - - - - - - - - - - - - - - - - - -
(d) Functions of elliptic compensators and half-
shades----------------------------------
12. References----------------------------------------
III. Measurement of rotation in circular degrees_-_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
1. Polariscopes with circular scales----- - - - - - - - - - - - - - - - - - -
(a) History of development - - - - - - - - - - - - - - - - - - - - - -
(b) Types of polarizers and polariscopes - - - - - - - - - - -
(1) Laurent and Jellet polarizers - - - - - - - - - -
(2) Lippich system - - - - - - - - - - - - - . sº ºm m. - as- a-- * *
(3) Sensitive-strip system - - - - - - - - - - - - - - - -
(c) Tests of polariscopes with circular scales_-_ _ _ _ _ _
(d) National Bureau of Standards equipment____ _ _ _
2. Light sources for circular-scale polariscopes---- - - - - - - - - -
(a) General------------------------------------
(b) Sodium------------------------------------
(1) Flame------------------------------
(2) Electric sodium lamp- - - - - - - - - - - - - - - - -
(c) Mercury lines-------------------------------
(d) Cadmium lines-----------------...------------
(1) General-----------------------------
(2) Bates cadmium-gallium lamp- - - - - - - - - -
(e) Lithium flame-------------------------------
(f) Remarks on purity of light----- - - - - - - - - - - - - - - -
3. Quartz control plates------ - - - - - - - - - - - - - - - - - - - - - - - - - -
(a) Requirements and methods of testing - - - - - - - - - -
(1) Crystalline purity------...-- - - - - - - - - - - -
(2) Planeness and parallelism of the faces--
(3) Axis error---------------------------
(4) Mounting---------------------------
(5) Measurement of rotation---- - - - - - - - - - -
IV Contents
III. Measurement of rotation in circular degrees—Continued.
3. Quartz control plates–Continued. Page
(b) National Bureau of Standards specifications_ _ _ _ 61
(1) Purity------------------------------ 61
(2) Planeness, parallelism - - - - - - - - - - - - - - - - 61
(3) Axis error--- - - - - - - - - - - - - - - - - - - - - - - - - 61
(4) Mounting----------------- - - - - - - - - - - 61
(5) Dimensions-- - - - - - - - - - - - - - - - - - - - - - - - 61
(c) Specifications of the International Commission
for Uniform Methods of Sugar Analysis for
quartz control plates--- - - - - - - - - - - - - - - - - - - - - 61
(d) Certification of quartz control plates--- - - - - - - - - 62
(e) Special tests- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 63
4. References----------------------------------------- 63
IV. Measurement of rotation in sugar degrees____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 64
1. Development of the saccharimeter_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 64
(a) Historical instruments - – - - - - - - - - - - - - - - - - - - - - - 64
(b) Modern instruments_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 65
(c) Adjustable sensitivity type - - - - - - - - - - - - - - - - - - - 70
2. Basis of saccharimeter calibration_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 73
(a) The French Sugar Scale- - - - - - - - - - - - - - - - - - - - - - 75
(b) The German, or Wentzke, Scale - - - - - - - - - - - - - - - 77
(c) The International Sugar Scale--- - - - - - - - - - - - - - - 77
(1) Herzfeld-Schönrock version__ _ _ _ 78
(2) Bates-Jackson version - - - - - - - - - - - - - - - -
(3) Amsterdam version (1932) - - - - - - - - - - - -
(4) Correction of saccharimeters to the
International Sugar Scale -- - - - - - - - - - 80
3. Additional constants of the quartz-wedge saccharimeter - 80
(a) Rotation ratios for quartz and sucrose solutions- 80
(b) Absolute rotation of normal sucrose solution--- 81
(c) Rotatory dispersion curves of quartz and nor-
mal sucrose solution - - - - - - - - - - - - - - - - - - - - - - - 81
(d) Rotation difference, in sugar degrees, for nor-
mal sucrose solution, between X = 5461 A
and A=5892.5 A_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -- - - - - - - . . . . 81
(e) Thickness of the normal quartz plate----- - - - - - - 81
(f) Specific rotation of sucrose_-- - - - - - - - - - - - - - - - - - 82
(g) Normal weight of dextrose_-_ _ _ _ _ _ _ _ _ _ _ _ ... - - - - 82
(h) Rotation of normal solution and the specific
rotation of dextrose--- - - - - - - - - - - - - - - - - - - - - - 83
(i) Specific rotations of other sugars. - - - - - - - - - - - - - 83
(j) Conversion and scale comparison factors-- - - - - - - 83
4. Light sources for saccharimeters. -- - - - - - - - - - - - - - - - - - - - 84
(a) General------------------------------------- 84
(b) Bichromate filter--- - - - - - - - - - - - - - - - - - - - - - - - - - 84
(c) Influence on reading -- - - - - - - - - - - - - - - - - - - - - - - - 87
(d) Types of lamps------------------------------ 88
(1) Monochromatic---- - - - - - - - - - - - - - - - - - - 88
(2) White light -- - - - - - - - - - - - - - - - - - - - - - - - 88
5. Certification of quartz control plates - - - - - - - - - - - - - - - - - - 91
6. References----------------------------------------- 91
V. Temperature corrections and control_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 92
1. Quartz-wedge saccharimeter - - - - - - - - - - - - - - - - - - - - - - - - - 92
2. Sucrose-------------------------------------------- 92
3. Combination of corrections for quartz-wedge saccharimeter
and sugars--------------------------------------- 93
(a) Sucrose------------------------------------ 93
(b) Application of temperature correction by means
of a quartz control plate------ - - - - - - - - - - - - - - 94
(c) Corrections for use in tropical countries_ _ _ _ _ _ _ _ 94
(d) Sugar mixtures------------------------------ 96
4. Thermostats---------- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 97
(a) Water-------------------------------------- 97
(b) Air---------------------------------------- 97
5. References----------------------------------------- 102
Contents V
Page
VI. Accessory apparatus--------------------------------------- 102
1. Polariscope tubes - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 102
(a) Types-------------------------------------- 102
(1) Ordinary---- - - - - - - - - - - - - - - - - - - - - - - - - 102
(2) Bates_-_ _ _ _ ** ** - - - - - - - - - - - - - - - - - - - -, … = ºme 103
(3) Special----------------------------- 103
(4) Water-jacketed for high-temperature
polarization - - - - - - - - - - - - - - - - - - - - - - - 105
(b) Temperature corrections_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 105
(c) Accuracy----------------------------------- 105
2. Cover glasses--------------------------------------- 106
3. Volumetric flasks------------ - - - - - - - - - - - - - - - - - - - - - - - - 106
(a) Specifications- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 106
(1) Material and annealing- - - - - - - - - - - - - - - 106
(2) Design------------------------------ 106
(3) Graduation marks----- - - - - - - - - - - - - - - - 107
(4) Unit of volume - - - - - - - - - - - - - - - - - - - - - - 107
(5) Standard temperature - - - - - - - - - - - - - - - - 107
(6) Inscriptions -- - - - - - - - - - - - - - - - - - - - - - - - 107
(b) Tolerances---------------------------------- 108
(1) Precision stamps--------------- - - - - - - 108
(2) Sugar-testing flask (Bates) - - - - - - - - - - - - 108
(3) Special----------------------------- 108
(4) Correction tables------ - - - - - - - - - - - - - - - 109
4. Thermometers--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 109
(a) General------------------------------------ 109
(b) Ice baths----------------------------------- 110
5. Weights------------------------------------------- 110
(a) Sugar-------------------------------------- 110
(b) Analytical---------------------------------- 111
(c) Reference standards - - - - - - - - - - - - - - - - - - - - - - - - - 111
(d) Certification------------ - - - - - - - - - - - - - - - - - - - - 111
(e) Submission of weights for test----- - - - - - - - - - - - - 112
6. Balances------------------------------------------- 112
7. References----------------------------------------- 113
PART 2. —RAW AND REFINED SUGARS AND SUGAR PRODUCTS
VII. Polarization of raw and refined sugars_-_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 115
1. Sampling and mixing of samples - - - - - - - - - - - - - - - - - - - - - - 115
2. Direct polarization-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 116
3. Clarification---------------------------------------- 119
(a) General------------------------------------ 119
(b) Alumina cream---------- - - - - - - - - - - - - - - - - - - - - 119
(c) Basic lead acetate- - - - - - - - - - - - - - - - - - - - - - - - - - - 120
(1) Preparation - - - - - - - - - - - - - - - - - - - - - - - - - 120
(2) Analysis---------------------------- 121
(3) Correction for volume of precipitate -- - - 122
(4) Effect on sucrose----- - - - - - - - - - - - - - - - - 124
(5) Effect on levulose- - - - - - - - - - - - - - - - - - - - 124
(d) Basic lead nitrate (Herles solution) _ _ _ _ _ _ _ _ _ _ _ _ 124
(e) Hypochlorite (Zameron method) - - - - - - - - - - - - - - 125
(f) Hydrosulfite--------------------- - - - - - - - - - - - 125
(g) Bone char---------------------------------- 126
4. References----------------------------------------- 126
VIII. Clerget method----------------- - - - - - - - - - - - - - - - - - - - - - - - - - - - 126
1. Introduction--------------------------------------- 126
2. Acid methods--------------------- - - - - - - - - - - - - - - - - - - 127
(a) Basic values of the Clerget divisor__ _ _ _ _ _ _ _ _ _ _ _ 127
(b) Velocity of inversion of sucrose_--_ _ _ _ _ _ _ _ _ _ _ _ _ 132
(c) Influence of concentration of sugar on the
Clerget divisor---------------------------- 133
(d) Effect of varying temperature on the Clerget
divisor----------------------------------- 134
(e) Effect of hydrochloric acid-------------------- 136
VI Contents
VIII. Clerget method—Continued.
2. Acid methods—Continued. Page
(f) Effect of various reagents on the rotation of
invert sugar------------------------------ 137
(g) Rotation of sugar mixtures and the evaluation
of ”------------------------------------- 138
(h) Influence of reagents on the rotation of su-
CIOS8----------- - - - - - - - - - - - - - - - - - - - - - - - - - - 139
(i) Methods of compensation------ - - - - - - - - - - - - - - - 140
(j) Creydt raffinose formula------- - - - - - - - - - - - - - - - 143
k) Work of Zerban and collaborators - – - - - - - - - - - - - 145
3. Invertase methods--------------------- - - - - - - - - - - - - - 146
(a) Preparation of invertase. -- - - - - - - - - - - - - - - - - - - - 146
(1) Collodion ultrafilter- - - - - - - - - - - - - - - - - - 148
(2) Washing and concentration of invertase
solution by ultrafiltration_ _ _ _ _ _ _ _ _ _ _ 148
(3) Activity of invertase solution - - - - - - - - - - 150
(b) Purification of invertase by adsorption - - - - - - - - - 151
(c) Invertase divisor-- - - - - - - - - - - - - - - - - - - - - - - - - - - 152
4. Detailed analytical procedure -- - - - - - - - - - - - - - - - - - - - - - - - 152
(a) Considerations governing the choice of methods - 152
(b) Revised methods of Jackson and Gillis - - - - - - - - - 153
(1) General methods of inversion -- - - - - - - - - 153
(2) Method I- - - - - - - - - - - - - - - - - - - - - - - - - - - 154
(3) Method II-- - - - - - - - - - - - - - - - - - - - - - - - - 154
(4) Method IV -------- - - - - - - - - - - - - - - - - - - 155
(c) Acid methods of the Association of Official Agri-
cultural Chemists------ - - - - - - - - - - - - - - - - - - - - 155
(1) Determination of sucrose by polarization
before and after inversion with hydro-
chloric acid -- - - - - - - - - - - - - - - - - - - - - - 155
(2) Determination of sucrose and raffinose
by polarization before and after inver-
sion with hydrochloric acid - - - - - - - - - - 156
(d) Invertase methods of the Association of Official
Agricultural Chemists -- - - - - - - - - - - - - - - - - - - - - 157
(1) Determination of sucrose - - - - - - - - - - - - - 157
(2) Sucrose and raffinose by polarization be-
fore and after treatment with two
enzyme preparations_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1.59
(e) Double-acid method of Osborn and Zisch-- - - - - - 160
(f) Methods of other nations----- - - - - - - - - - - - - - - - - 162
5. References----------------------------------------- 164
IX. Chemical methods for the determination of reducing sugars - - - - 165
1. Theoretical and general-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 165
(a) Introduction------. ------------------------- 165
(b) Reducing sugars in alkaline solution - - - - - - - - - - - 165
(c) Copper-tartrate complexes--- - - - - - - - - - - - - - - - - - 166
(d) Classification of reducing sugars -- - - - - - - - - - - - - - 167
(e) Modern investigations - - - - - - - - - - - - - - - - - - - - - _ _ 167
(f) Clarification of crude products_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 169
2. Methods which require filtration of cuprous oxide-- - - - - - 170
(a) Munson and Walker unified method_ _ _ _ _ _ _ _ _ _ _ 170
(1) Preparation of Soxhlet reagents_-_ _ _ _ _ _ 170
(2) Procedure--------------------------- 170
(b) Hammond redetermination of Munson and Walk-
er values--------------------------------- 170
(c) Allihn method for the determination of dextrose.-- 173
(d) Quisumbing and Thomas method -- - - - - - - - - - - - - 173
(e) Bertrand method -- - - - - - - - - - - - - - - - - - - - - - - - - - - 174
(f) Herzfeld method for determination of less than
1.5 percent of invert sugar in sucrose_ _ _ _ _ _ _ _ 174
(g) Meissl and Hiller method for determining invert
sugar admixed with sucrose in all proportions-- 175
(h) Brown, Morris, and Millar method for reducing
sugar in molasses-------------------------- 177
Contents VII
Page
IX. Chemical methods for the determination of reducing sugars—Con.
3. Determination of copper------------ - - - - - - - - - - - - - - - - - 178
(a) General------------------------------------ 178
(b) Gravimetric methods - - - - - - - - - - - - - - - - - - - - - - - - 178
(c) Electrolytic deposition from nitric acid solution_ _ 180
(d) Thiosulfate method -- - - - - - - - - - - - - - - - - - - - - - - - - 180
(e) Permanganate method - - - - - - - - - - - - - - - - - - - - - - - 182
(f) Dichromate methods -- - - - - - - - - - - - - - - - - - - - - - - - 183
(1) Electrometric---- - - - - - - - - - - - - - - - - - - - - 183
(2) Colorimetric------------------...------ 184
4. Volumetric methods--------------------------------- 185
(a) Lane and Eynon method - - - - - - - - - - - - - - - - - - - - - 185
(1) Standard method of titration_ _ _ _ _ _ _ _ _ _ 186
(2) Applications of the method ------------ 187
(b) Scales method------------------------------ 189
(1) General----------------------------- 189
(2) Method for making sugar determina-
tions----------------------------- 192
(c) Schoorl method for invert sugar in cane molasses- 192
(d) Methods for small percentages of invert sugar in
SUCTOS8-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - I93
(1) Ofner method - - - - - - - - - - - - - - - - - - - - - - - 193
(2) Spengler, Tödt, and Scheuer method - - - 194
(3) Luff-Schoorl method - - - - - - - - - - - - - - - - - | 95
5. Microchemical methods - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - 196
(a) Somogyi modification of Shaffer and Hartmann
micromethod for dextrose---- - - - - - - - - - - - - - - - 196
(b) Benedict modification of Folin and Wu method - - 197
(c) Ferricyanide micromethod of Hagedorn and
Jensen----------------------------------- 198
(a) Pot method of Main for determination of reduc-
ing sugars in raw sugars and similar products-- 199
(b) de Whalley method for the determination of in-
vert sugar in refined white sugars --- - - - - - - - - - 201
7. Electrometric method for the determination of reducing
Súšal"S- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 201
8. Selective methods-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 203
(a) Jackson and Mathews modification of Nyns
method for levulose--- - - - - - - - - - - - - - - - - - - - - - 203
(1) Standard solutions-- - - - - - - - - - - - - - - - - - 204
(2) Analytical procedure - - - - - - - - - - - - - - - - - 204
(3) Analysis of dextrose-levulose mixtures-- 205
(b) Hinton and Macara method for levulose in con-
densed milk------------------------------- 205
(c) Sichert and Bleyer modification of Barfoed
copper acetate method for monoses - - - - - - - - - - 206
(d) Monier-Williams modified Barfoed method for
monose sugars in condensed milk- - - - - - - - - - - - 207
(e) Iodometric determination of aldoses - - - - - - - - - - - 208
(f) Hinton and Macara chloramine-T method for
- the determination of aldoses - - - - - - - - - - - - - - - _ 211
9. References----------------------------------------- 212
X. Analysis of sugar mixtures---------------------------------- 214
1. Introduction--------------------------------------- 214
2. Selective methods----------------------------------- 215
(a) Recapitulation of previously described methods - 215
(b) Invert sugar by polarization at two temperatures - 215
(c) Levulose by polarization at two temperatures-- - 217
(d) Galactose by mucic acid precipitation_ _ _ _ _ _ _ _ _ _ 218
(e) Determination of mannose as phenylhydrazone- - 218
(f) Determination of arabinose as diphenylhydra-
ZODe- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 219
(g) Determination of uronic acids-- - - - - - - - - - - - - - - - 219
VIII Contents
X. Analysis of sugar mixtures—Continued. Page
3. Determination of two sugars in a mixture- - - - - - - - - - - - - - 222
(a) Two sugars by combination of two polarimetric
equations--------------------------------- 222
(b) Two sugars by combined polariscopic and reduc-
tion equations----------------------------. 222
(1) Browne formulas - - - - - - - - - - - - - - - - - - - - 222
(2) Mathews formula- - - - - - - - - - - - - - - - - - - - 223
(c) Two sugars by combination of two reduction
equations-------------------------------- 224
(1) General----------------------------- 224
(2) Sucrose and lactose in dairy products by
two reduction processes- - - - - - - - - - - - .. 225
4. Determination of three sugars in a mixture__ _ _ _ _ _ _ _ _ _ _ _ 225
(a) General------------------------------------ 225
(b) Three sugars by combination of polarimetric and
reduction methods and one selective method - - 225
(c) Three sugars by combination of total reducing
power and two selective methods - - - - - - - - - - 226
(1) Sucrose, dextrose, and levulose in raw
sm. “ - - - - - - - - - - = * = = <-- a-- - - - - - - - - * * * * 227
(2) Sucrose, dextrose, and levulose in cane
molasses-------------------------- 229
(d) Analysis of a mixture of three sugars by three
reduction processes- - - - - - - - - - - - - - - - - - - - - - - - 230
(1) Steinhoff method for dextrose, maltose,
and dextrin - - - - - - - - - - - - - - - - - - - - - - - 230
5. References----------------------------------------- 231
XI. Analysis of special products-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 232
1. Honey--------------------------------------------- 232
(a) Preparation of sample--- - - - - - - - - - - - - - - - * = -- - - - -º 232
(1) Liquid or strained honey---- - - - - - - - - - - 232
(2) Comb honey-- - - - - - - - - - - - - - - - - - - - - - - 232
(b) Moisture----------------------------------- 232
(c) Ash---------------------------------------- 232
(d) Direct polarization—tentative------ - - - - - - - - - - - 232
(1) Immediate direct polarization - - - - - _ _ _ _ 232
(2) Constant direct polarization-- - - - - - - - - - 232
(3) Mutarotation-------- - - - - - - - - - - - - - - - - 232
(4) Direct polarization at 87° C_ _ _ _ _ _ _ _ _ _ _ 232
(e) Invert polarization—tentative- - - - - - - - - - - - - - - - 232
(1) At 20° C---------------------------- 232
(2) At 87° C----- - - - - - - - - - - - - - - - - - - - - - - - 232
(f) Reducing sugars----------------------------- 233
(g) Sucrose------------------------------------ 233
(h) Levulose—tentative- - - - - - - - - - - - - - - - - - - - - - - - - 233
(i) Dextrose—tentative- - - - - - - - - - - - - - - - - - - - - - - - - 233
(j) Dextrin (approximate)—tentative- - - - - - - - - - - - - 234
(k) Free acid----------------------------------- 234
(1) Commercial glucose-----------...-- - - - - - - - - - - - - 234
(1) Qualitative test —tentative_ _ _ _ _ _ _ _ _ _. 234
(2) Quantitative method–tentative - - - - - - - 234
(m) Commercial invert sugar-- - - - - - - - - - - - - - - - - - - - 235
(1) Resorcinol test—tentative_--_ _ _ _ _ _ _ _ _ _ 235
(2) Aniline chloride test—tentative------. _ 235
(n) Diastase—tentative-------- - - - - - - - - - - - - - - - - - - 235
2. Maple products------------------------------------- 235
(a) Preparation of sample------ - - - - - - - - - - - - - - - - - - 235
(1) Sirup------------------------------- 235
(2) Sugar and other solid and semisolid
products—tentative -- - - - - - - - - - - - - - - 236
(b) Moisture or solids- - - - - - - - - - - - - - - - - - - - - - - - - - - 236
(1) Maple sugar----------------------. - 236
(2) Maple sirup, maple cream, etc.-- - - - - - - - 236
(c) Ash---------------------------------------- 236
(d) Polarization-------------------------------- 236
(1) Direct polarization-- - - - - - - - - - - - - - - - - - 236
(2) Invert polarization-...-- - - - - - - - - - - - - - - - 236
Contents IX
XI. Analysis of special products—Continued.
2. Maple products—Continued. Page
(e) Sucrose—polarimetric method_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 236
(f) Sucrose–chemical method_-_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 236
(g) Reducing sugars as invert Sugar- 2 - - - - - - - - - - - - - 237
(1) Before inversion - - - - - - - - - - - - - - - - - - - - - 237
(2) After inversion - - - - - - - - - - - - - - - - - - - - - - 237
(h) Commercial glucose -- - - - - - - - - - - - - - - - - - - - - - - - 237
(1) Substances containing little or no invert
Sugar- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 237
(2) Substances containing invert sugar-- - - - 237
(i) Lead number------------------------------- 237
(1) Canadian lead number (Fowler modifi-
cation).----------------- :- — — — — — — — — — 237
(2) Winton lead number- - - - - - - - - - - - - - - - 238
(j) Conductivity value---------- - - - - - - - - - - - - - - - - 238
(1) Apparatus-------------------------- 238
(2) Determination of the cell constant - - - 239
(3) Determination----------------------- 239
(k) Malic-acid value (Cowles)—tentative- - - - - - - - - - 239
3. Determination of sugars in milk products_ _ _ _ _ _ _ _ _ _ _ _ _ _ 239
(a) Determination of the volume of the precipitate - 240
(b) Lactose------------------------------------ 240
(1) Optical method-- - - - - - - - - - - - - - - - - - - - - 240
(2) Chemical method - - - - - - - - - - - - - - - - - - - - 240
4. References----------------------------------------- 241
XII. Determination of pentosans--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 241
1. Descriptive----------------------------------------- 241
2. Standard method for the estimation of furfural by means
of phloroglucin----------------------------------- 243
3. Method for the estimation of furfural according to Kull-
gren and Tydén----------------------------------- 245
(a) Procedure applicable to the determination of
pentosans or methylpentosans-------- - - - - - - - 245
(b) Estimation of pentoses or pentosans in the
presence of hexoses and polyoses-- - - - - - - - - - - 246
4. Distillation and volumetric determination of furfural from
xylose------------------------------------------- 246
5. References----------------------------------------- 247
XIII. Densinetry----------------------------------------------- 247
1. General-------------------------------------------- 247
2. Degrees Brix (or Balling) - - - - - - - - - - - - - - - - - - - - - - - - - - - - 248
3. Degrees Baumé----------------------- - - - - - - - - - - - - - - 248
4. Determination of density-- - - - - - - - - - - - - - - - - - - - - - - - - - - 249
(a) By means of hydrometers- - - - - - - - - - - - - - - - - - - - 249
(b) By means of picnometers-- - - - - - - - - - - - - - - - - - - - 250
(1) General----------------------------- 250
(2) Method of Newkirk-- - - - - - - - - - - - - - - - - 251
(3) Weight per gallon of molasses - - - - - - - - - 251
(c) By means of direct-reading balance- - - - - - - - - - - - 252
(d) By means of analytical balance------ - - - - - - - - - - 253
5. Density of sucrose solutions----------- - - - - - - - - - - - - - - - 253
6. References----------------------------------------- 254
XIV. Refractometry - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 254
1. General__ _ _ _ _ _ _ ------------------------------------ 254
2. Principles of the Abbe refractometer____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 255
(a) Dispersion---------------------------------- 256
(b) Effect of temperature_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 256
(c) Illumination-------------------------------- 257
(d) Adjustment of the instrument---- - - - - - - - - - - - - - 257
(e) Method of determining refractive index_ _ _ _ _ _ _ _ 258
3. Immersion refractometer------- - - - - - - - - - - - - - - - - - - - - - - 259
4. Special refractometers- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 260
5. References----------------------------------------- 261
XV. Determination of moisture--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 26I
1. General-------------------------------------------- 261
Contents
XV. Determination of moisture—Continued. Page
3. Methods of the Association of Official Agricultural
Chemists----------------------------------------- 262
(a) Direct drying------------------------------- 262
(b) Vacuum drying----------------------------- 262
(c) Drying on quartz sand----------------------- 262
4. Additional methods--------------------------------- 262
5. References----------------------------------------- 263
XVI. Determination of ash-------------------------------------- 263
1. Sulfate method ------------------------------------- 263
2. Methods of the Association of Official Agricultural
Chemists----------------------------------------- 264
3. Additional methods--------------------------------- 264
4. References----------------------------------------- 265
XVII. Electrical conductance of sugar solutions - - - - - - - - - - - - - - - - - - - - - 265
1. Introduction--------------------------------------- 265
2. Apparatus----------------------------------------- 266
(a) Bridge------------------------------------- 266
(b) Null-point indicator- - - - - - - - - - - - - - - - - - - - - - - - - 267
(c) Oscillator----------------------------------- 268
(d) Conductivity cell---------------------------- 268
(e) Electrodes---------------------------------- 269
(f) Constant-temperature bath -- - - - - - - - - - - - - - - - - - 270
3. Procedure------------------------------------------ 27 |
(a) Equilibrium water--------------------------- 27]
(b) Preparation of potassium chloride solution___ _ _ _ 271
(c) Determination of cell constants - - - - - - - - - - - - - - - 272
(d) Checking of cells - - - - - - - - - - - - - - - - - - - - - - - - - - - - 274
4. Specific conductance of solutions of sugar products_ _ _ _ _ _ 275
(a) Ash determination by the “C-ratio” method -- - - 275
(b) Zerban and Sattler conductance method for ash – 276
(1) Raw cane and soft sugars-- - - - - - - - - - - - 277
(2) Refinery sirups and molasses produced
without char treatment__ _ _ _ _ _ _ _ _ _ _ _
(3) Raw and refinery sirups and molasses of
unknown origin-------------------- 277
5. References----------------------------------------- 278
XVIII. Measurement of hydrogen-ion concentration — — — — — — — — — — — — — — — — — — 279
1. Introduction --------------------------------------- 279
2. Potentiometric methods----- - - - - - - - - - - - - - - - - - - - - - - - - - 280
(a) Potentiometers--------- - - - - - - - - - - - - - - - - - - - - - 280
(b) Calomel electrodes------ - - - - - - - - - - - - - - - - - - - - - 282
(c) Hydrogen electrodes -- - - - - - - - - - - - - - - - - - - - - - - - 285
(d) Quinhydrone electrode - - - - - - - - - - - - - - - - - - - - - - - 289
(e) Glass electrode------------------------------ 289
(f) Silver-silver chloride electrode_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 292
3. Automatic recording and control of pH - - - - - - - - - - - - - - - - 293
4. Colorimetric methods------- - - - - - - - - - - - - - - - - - - - - - - - - - 294
(a) With standard buffer solutions_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 294
(b) Without buffer solutions—Gillespie method_-_ _ _ 297
5. References----------------------------------------- 299
XIX. Colorimetry----------------------------------------------- 300
1. Introduction--------------------------------------- 300
2. Color nomenclature in the sugar industry - - - - - - - - - - - - - - 301
3. Visual spectrophotometric apparatus – - - - - - - - - - - - - - - - - 304
(a) Bausch & Lomb spectrophotometric equipment-- 304
(b) Gaertner polarizing spectrophotometer_ _ _ _ _ _ _ _ _ 307
(c) Königs-Martens spectrophotometer with auxili-
ary equipment designed at the National Bu-
reau of Standards------------------------- 308
(d) Keuffel & Esser color analyzer - - - - - - - - - - - - - - - - 310
4. Apparatus for abridged spectrophotometry - - - - - - - - - - - - - 31 ||
(a) Ives tint photometer----------------- - - - - - - - - 3]. I
(b) Modified Stammer colorimeter_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 312
(c) Duboscq colorimeter--- - - - - - - - - - - - - - - - - - - - - - - 312
(d) Zeiss-Pulfrich photometer - - - - - - - - - - - - - - - - - - - - 315
Contents XI
XIX. Colorimetry—Continued. Page
5. Photoelectric photometers - - - - - - - - - - - - - - - - - - - - - - - - - - - 316
(a) Sandera objective sugar colorimeter----- - - - - - - - 317
(b) Hirschmüller apparatus - - - - - - - - - - - - - - - - - - - - - - 3.18
(c) Compensating vacuum phototube photometer--- 319
(d) Keane and Brice sugar photometer- - - - - - - - - - - - 321
(e) Mercury-arc spectral filters-- - - - - - - - - - - - - - - - - - 324
6. Filter aids and filtration of solutions---- - - - - - - - - - - - - - - - 324
(a) Preparation of asbestos------ - - - - - - - - - - - - - - - - - 324
(b) Asbestos filters------------------------------ 325
(c) Preparation and filtration of the solution with
asbestos---------------------------------- 326
(d) Preparation of diatomaceous earth and filtration- 327
7. Dilution of color------------------------------------ 329
(a) Volume basis------------------------------- 329
(b) Weight basis-------------------------------- 330
(c) Dilution with Solid Sugar- - - - - - - - - - - - - - - - - - - - - 331
(d) Calculation of Brix-------------------------- 332
8. Summary of the procedure- - - - - - - - - - - - - - - - - - - - - - - - - - - 332
9. Color standards for Solid sugars--- - - - - - - - - - - - - - - - - - - - - 334
10. Decolorizing efficiency of carbons_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 334
(a) Finely divided carbons--- - - - - - - - - - - - - - - - - - - - - 334
(1) Determination of moisture - - - - - - - - - - - - 334
(2) Decolorizing efficiency--- - - - - - - - - - - - - - 334
(b) Granular bone black----------------- - - - - - - - - 338
11. References----------------------------------------- 340
XX. Measurement of turbidity-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 341
1. Method of Balch------------------------------------ 341
2. Methods employing the Zeiss nephelometer--- - - - - - - - - - - 342
(a) Description of the apparatus_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 342
(b) Procedure of Zerban, Sattler, and Lorge_ _ _ _ _ _ _ _ 345
(c) Procedure of Landt and Witte_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 349
3. References----------------------------------------- 350
XXI. Viscosity of Sugar Solutions-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 350
1. Theoretical----------------------------------------- 350
2. Capillary tube viscometers-- - - - - - - - - - - - - - - - - - - - - - - - - - 352
(a) Ostwald viscometer-------------------------- 352
(b) Bingham viscometer------------------------- 352
(c) Ubbelhode viscometer------ - - - - - - - - - - - - - - - - - - 353
3. Short-tube viscometers-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 353
4. Falling-ball viscometers---- - - - - - - - - - - - - - - - - - - - - - - - - - - 354
(a) Hoeppler viscometer------------------------- 354
5. Rotational viscometers- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 354
(a) MacMichael viscometer--- - - - - - - - - - - - - - - - - - - - 354
(b) Stormer viscometer-------- - - - - - - - - - - - - - - - - - - 355
6. Calibration of viscometers--- - - - - - - - - - - - - - - - - - - - - - - - - 355
7. Wiscosity of various sugar solutions_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 357
(a) Sucrose------------------------------------ 357
(b) Miscellaneous------------------------------- 358
8. References----------------------------------------- 359
XXII. Solubility of the common sugars---------- - - - - - - - - - - - - - - - - - - - 359
1. Solubility of sucrose in water--- - - - - - - - - - - - - - - - - - - - - - - 359
2.’ Solubility of dextrose in water-- - - - - - - - - - - - - - - - - - - - - - - 359
3. Solubility of levulose in water- - - - - - - - - - - - - - - - - - - - - - - - 360
4. Solubility of lactose in water- - - - - - - - - - - - - - - - - - - - - - - - - 361
5. Solubility of Sugars in sugar mixtures------------------ 361
(a) Three-component systems-------------------- 361
(b) Solubility of sucrose in invert-sugar solution - - - - 364
References----------------------------------------- 365
XXIII. Boiling points of sucrose solutions-- - - - - - - - - - - - - - - - - - - - - - - - - - 365
1. General-------------------------------------------- 365
2. Definition of boiling point.---------- - - - - - - - - - - - - - - - - - - 366
3. Relationship between vapor pressure and concentration
of solute in a liquid------------------------------ 366
4. Relationship between vapor-pressure lowering and boil-
ing-point elevation-------------------------------- 367
XII Contents
XXIII. Boiling points of sucrose solutions—Continued. Page
5. Relationship between boiling-point elevation and concen-
tration of solute---------------------------------- 368
6. Relationship between boiling-point elevation and atmos-
pheric pressure------------------------------------ 368
7. Derivation of boiling-point elevation table - - - - - - - - - - - - - 369
8. References----------------------------------------- 370
XXIV. Candy tests------------------------- - - - - - - - - - - - - - - - - - - - - - - 370
1. Introduction--------------------------------------- 370
(a) General------------------------------------ 370
(b) Hooker test----- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 370
2. National Bureau of Standards method for barley sugar -- 371
(a) Procedure---------------------------------- 372
(b) Observations for interpretation of results - – - - - - - 373
(1) Foam number----------------------- 373
(2) Examination of the plaque--- - - - - - - - - - 373
(3) Examination of the candy in aqueous
solution-------------------------- 374
(c) Apparatus---------------------------------- 375
(1) Boiling-vessels---------- - - - - - - - - - - - - - 375
(2) Heating devices----- - - - - - - - - - - - - - - - - - 376
(3) Thermometers--- - - - - - - - - - - - - - - - - - - - - 382
(4) Cooling slabs -- - - - - - - - - - - - - - - - - - - - - - - 383
(d) Heating cycle.------------------. . . . --------. 384
(1) Duration of the cooking interval - - - - - 384
(2) Duration of the cooling interval - - - - - - 385
(e) Samples------------------------------------ 385
(1) Types of materials tested_ _ _ _ _ _ _ _ _ _ _ _ _ 385
(2) Reference samples – - - - - - - - - - - - - - - - 385
(f) Improvements of the National Bureau of Stand-
- ards method over the Hooker procedure_ _ _ _ _ _ _ 385
(g) Utility and reliability of the candy tests --- - - - - - - 386
3. Conclusions---------------------------------------- 389
4. References- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 390
XXV. Preparation and purification of pure sugars – . . . . . . . . . . . . . . . . . 390
1. Dextrose--- - - - - - - - - - - - - - - - -- - - - - - - - -- - - - - - - - - - - - - - - - - - - - 390
2. Sucrose- - - - - - - - - - - - - - - - - - - - - - - – -- - - - - - - - - - - - - - - - - - - - - - 392
(a) Method of Herzfeld- - - - - - - - - - - - - - - - - - - - - - - - - - 392
(b) Method of Herles--- - - - - - - - - - - - - - - - - - - - - - - - - 392
(c) Method of the International Commission for Uni-
form Methods of Sugar Analysis------------- 392
(d) Method of Bates and Jackson - - - - - - - - - - - - - - - - - 392
(e) Modification of method of Bates and Jackson --- 396
(f) Analysis---------------. - - - - - - - - - - - - - - - - - - - - - - - 396
3. Levulose------------------------------------------- 398
(a) Preparation of inulin -- - - - - - - - - - - - - - - - - - - - - - - - 398
(b) Preparation of levulose-- - - - - - - - - - - - - - - - - - - - - - 399
(1) Hydrolyzed inulin_ _ _ _ _ _ _ _ _ _ - - - - - - - - - - 399
(2) Preparation of invert sugar--- - - - - - - - - - 399
(3) Hydrolysis of plant juices - – - - - - - - - - - - 399
(4) Precipitation of calcium levulate -- - - - - - 400
(5) Crystallization of levulose---- - - - - - - - - - 404
4. References----------------------------------------- 405
XXVI. Purity--------------------------------------------------- 406
1. Calculation. ---------------------------------------- 406
2. References------ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 408
XXVII. Packing of sucrose--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 408
1. Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 408
2. Crystal dimension----------------------------------- 408
3. Volume of crystals and voids - - - - - - - - - - - - - - - - - - - - - - - - - 408
4. Weight of crystals------- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 409
5. Area of the crystals- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 409
6. References----------------------------------------- 409
Contents XIII
PART 3.—PREPARATION AND PROPERTIES OF THE SUGARS AND
THEIR DERIVATIVES Page
XXVIII. Optical activity, configuration, and structure in the sugar group- - 411
1. Constitution of the sugars and their interrelationships-- - - 411
2. Optical activity in Organic compounds_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 417
3. Stereoisomerism of the Sugars - - - - - - - - - - - - - - - - - - - - - - - - - 420
4. Nomenclature of the alpha and beta sugars----- - - - - - - - - 424
5. Correlations between optical rotation and structure_ _ _ _ _ 428
6. Correlations between the configurations and the chemical
properties of the Sugars -- - - - - - - - - - - - - - - - - - - - - - - - - - - 435
7. References----------------------------------------- 437
XXIX. Mutarotation and sugars in solution - - - - - - - - - - - - - ... - - - - - - - - - - 439
1. Characteristics of the equilibrium state - - - - - - - - - - - - - - - - 439
2. Crystallization and solution - - - - - - - - - - - - - - - - - - - - - - - - - - 441
3. Mutarotation of freshly dissolved sugars - – - - - - - - - - - - - - - 442
(a) Mutarotation equations--- - - - - - - - - - - - - - - - - - - - 442
(b) Measurement of mutarotation - - - - - - - - - - - - - - - - - 446
(c) Velocity and equilibrium constants for the muta-
rotation reactions---------...--- - - - - - - - - - - - - - 447
(d) Effect of temperature on the mutarotation rate -- 447
(e) Effect of temperature on the equilibrium state_ _ _ 448
(f) Effect of acids and bases on the mutarotation
rates------------------------------------- 451
(g) Effect of the solvent and other substances on the
equilibrium state- - - - - - - - - - - - - - - - - - - - - - - - - 453
4. Chemical methods for studying the equilibrium state - - - 454
5. References----------------------------------------- 456
XXX. Methods for the preparation of certain sugars - - - - - - - - - - - - - - - - - 456
1. d-Allose-------------------------------------------- 456
2. l-Arabinose----------------------------------------- 457
3. Cellobiose (4-(8-d-glucopyranosido)-d-glucose).----- - - - - - - 459
4. 2-Desoxygalactose------- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 460
5. l-Fucose (l-galactomethylose) - - - - - - - - - - - - - - - - - - - - - - - - 460
6. d-Galactose---------------------------------------- 462
7. Gentiobiose (6-(3-d-glucopyranosido)-d-glucose) -- - - - - - - - 463
8. 4-Glucosidomannose (4-(6-d-glucopyranosido)-d-mannose) 464
9. oſ-d-Gulose. CaCl2.H2O - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 465
10. Lactose (4-(3-d-galactopyranosido)-d-glucose) -- - - - - - - - - - 467
11. Lactulose (4-(6-d-galactopyranosido)-d-fructose).---- - - - - - 467
12. d-Lyxose------------------------------------------- 469
13. Maltose (4-(o-d-glucopyranosido)-d-glucose) - - - - - - - - - - - - 470
14. d-Mannose----------------------------------------- 471
15. Melezitose (d-glucosido-sucrose) -- - - - - - - - - - - - - - - - - - - - - - 472
16. Melibiose (6-(o-d-galactopyranosido)-d-glucose) - - - - - - - - - 473
17. Neolactose (4-(8-d-galactopyranosido)-d-altrose) - - - - - - - - 474
18. Raffinose (d-galactosido-sucrose) - - - - - - - - - - - - - - - - - - - - - - 475
19. l-Rhamnose (l-mannomethylose) - - - - - - - - - - - - - - - - - - - - - 475
20. d-Ribose.------------------------------------------- 476
21. l-Sorbose---- - - - - - - - - - - - - - - - - - - - - - ----------------...- 479
22. d-Talose------------------------------------------- 479
23. Turanose (3-(o-d-glucopyranosido)-d-fructose) - - - - - - - - - - 480
24. d-Xylose------------------------------------------- 481
XXXI. Methods for the preparation of certain sugar derivatives--- - - - - 482
1. Acetal and ketal derivatives-- - - - - - - - - - - - - - - - - - - - - - - 482
(a) Sulfuric acid method for the preparation of
acetone derivatives- - - - - - - - - - - - - - - - - - - - - - - 483
(1) 1,2-5,6-Diacetone-d-glucose - - - - - - - - - - 483
(2) 1,2-4,5-Diacetone-d-fructose------ - - - - - 483
(b) Copper sulfate method for the preparation of
acetone derivatives – - - - - - - - - - - - - - - - - - - - - 484
(1) Monoacetone and diacetone derivatives
of methyl ox-d-mannopyranoside - - - - - - 484
(c) Hydrolysis of the diacetone derivative to give a
monoacetone derivative – - - - - - - - - - - - - - - - - - - 484
(1) 1,2-Monoacetone-d-glucose - - - - - ------- 484
(d) Zinc chloride method for preparing benzylidine
derivatives------------------------------- 484
XIV Contents
XXXI. Methods for the preparation of certain sugar derivatives—Con.
1. Acetal and ketal derivatives—Continued. Page
(e) References---------------------------------- 485
2. Acetyl derivatives----------------------------------- 485
(a) Low-temperature pyridine method of acetylation- 486
(1) Pentaacetyl-o-d-talose-- - - - - - - - - - - - - - - 487
(b) Low-temperature sulfuric acid method of acety-
lation ------------------------------------ 487
(1) Pentaacetyl-3-d-fructose- - - - - - - - - - - - - - 487
(c) Low-temperature zinc chloride method of acetyla-
tion-------------------------------------- 488
(1) Pentaacetyl-3-d-mannose-------- - - - - - - 488
(d) Sodium acetate method of acetylation-- - - - - - - - - 488
(1) Pentaacetyl-3-d-galactose_ _ _ _ _ _ _ _ _ _ _ _ _ 488
(e) High-temperature zinc chloride method of acety-
lation ------------------------------------ 489
(1) Octaacetyl-4-(8-d-glucosido)-o-d-man-
11989------- - - - - - - - - - - - - - - - - - - - - - - - 489
(f) Preparation of acetyl derivatives from halogeno-
acetyl derivatives -- - - - - - - - - - - - - - - - - - - - - - - - - 489
(1) Tetraacetyl-3-d-xylose--- - - - - - - - - - - - - - 489
(g) Interconversion of acetates-- - - - - - - - - - - - - - - - - - 489
(1) Preparation of pentaacetyl-o-d-mannose
from pentaacetyl-3-d-mannose- - - - - - - 489
(2) Preparation of hexaacetyl-o-d-o-manno-
heptose from hexaacetyl-3-d-o-manno-
heptose--- - - - - - - - - - - - - - - - - - - - - - - - --- - - 490
(h) Preparation of open-chain acetates - - - - - - - - - - - - 490
(1) Pentaacetyl-aldehydo-d-glucose--- - - - - - - 490
(2) Pentaacetyl-keto-d-fructose- - - - - - - - - - - - 491
(i) Preparation of partially acetylated pyranoses - - - - 491
(1) Heptaacetyl-4-(6-d-glucosido)-d-man-
TiOSC-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 491
(2) Hexaacetyl-4-(6-d-glucosido)-d-mannose 491
(3) 1,3,4,5-Tetraacetyl-d-fructose-- - - - - - - - - 492
(j) Preparation of orthoacetates - - - - - - - - - - - - - - - - - - 492
(1) 1,2-(hexaacetyl-4-glucosidom an nose)
methyl orthoacetate and methyl hepta-
acetyl-4-(6-d-glucosido)-3-d-manno-
pyranoside------------------------ 492
(k) Methods for removing acetyl groups-- - - - - - - - - - 493
(1) Catalytic barium methylate method - - - - 493
(2) Rapid deacetylation with hot sodium
methylate------------------------- 494
(3) Deacetylation with an excess of alkali- - - 494
(l) Quantitative determination of acetyl groups---. - 494
(1) Determination of acetyl groups by alka-
line hydrolysis - - - - - - - - - - - - - - - - - - - - - 495
(2) Determination of acetyl groups by acid
hydrolysis------------------------- 495
(3) Determination of acetyl groups by the
ethyl acetate method -- - - - - - - - - - - - - - 495
(4) Determination of acetyl groups and
halogen in halogeno-acetyl deriva-
- tives----------------------------- 497
(m) References--------------------------------- 497
3. Halogeno-acetyl derivatives - - - - - - - - - - - - - - - - - - - - - - - - - - 498
(a) Preparation of fluoro-derivatives - - - - - - - - - - - - - - 498
(1) 1-Fluoro-2,3,4,6-tetraacetyl-o-d-glucose – 498
(b) Preparation of chloro-derivatives- - - - - - - - - - - - - - 499
(1) 1-Chloro-2,3,4,6-tetraacetyl-o-d-glucose— 499
(2) 1-Chloro-2,3,4,6-tetraacetyl-o'-d-man-
(c) Preparation of bromo-derivatives -- - - - - - - - - - - - - 500
(1) 1–Bromo-2,3,4,6-tetraacetyl-o-d-glucose- 500
(2) 1-Bromo-2,3,4,6-tetraacetyl-o-d-talose - - 500
Comtents - XV
XXXI. Methods for the preparation of certain sugar derivatives—Con.
3. Halogeno-acetyl derivatives—Continued. Page
(d) Preparation of iodo-derivatives------------ - - - - 501
(1) 1-Iodo-heptaacetyl-4-(8-d-glucosido)-o'-
d-mannose------------------------ 501
(e) Transformation of the acetate of one sugar to the
halogeno-acetate of another Sugar----- - - - - - - - 501
(1) Conversion of octaacetylcellobiose to
fluoro-hexaacetylglucosidomannose, (1-
fluoro-hexaacetyl-4-(6-d-glucosido)-o'-
d-mannose).------------------------ 501
(2) Conversion of octaacetyllactose to
chloro-heptaacetylneolactose, (1-chloro-
heptaacetyl-4-(6-d-galactosido)-d-altrose) 502
(f) References---------------------------------- 502
4. Benzoyl derivatives------------...--------- - - - - - - - - _ _ _ 502
(a) Preparation of benzoyl derivatives with benzoyl
chloride in pyridine solution – - - - - - - - - - - - - - - - 503
(1) Pentabenzoyl-d-glucose- - - - - - - - - - - - - - - 503
(b) References---------------------------------- 503
5. Carbonate derivatives------------------------------- 503
(a) Preparation of carbonates with carbonyl chloride
in pyridine Solution-...-- - - - - - - - - - - - - - - - - - - - - 504
(1) 2,3-5,6-d-Mannose dicarbonate_ _ _ _ _ _ _ _ 504
(b) Preparation of carbonates with carbonyl chloride
in acetone solution------------------------ 504
(1) Monoacetone-d-glucose monocarbonate - 504
(c) Removal of the carbonate groups- - - - - - - - - - - - - - 504
(1) Methyl ox-d-mannofuranoside from
methyl 2,3-5,6-o-d-mannoside dicar-
bonate--------------------------- 504
(2) Ethyl 3-d-glucofuranoside--- - - - - - - - - - - 504
(d) References---------------------------------- 505
6. p-Toluenesulfonyl derivatives---- - - - - - - - - - - - - - - - - - - - - - 505
(a) Preparation of tosyl derivatives with p-toluene-
sulfonyl chloride in pyridine solution_ _ _ _ _ _ _ _ 505
(1) 5-Tosyl monoacetone-3-l-rhamnose-- - - - 505
(b) References---------------------------------- 506
7. Methyl ethers-------------------------------------- 506
(a) Methylation with methyl iodide and silver oxide - 506
(1) Methyl 2,3,4,6-tetramethyl-o-d-galacto-
id
S1019– - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 506
(b) Methylation with dimethyl sulfate and sodium
hydroxide-------------------------------- 507
(1) Heptamethylsucrose------ - - - - - - - - - - - - 507
(c) Preparation of methyl ethers from the acetates - – 507
(1) Trimethylinulin – - - - - - - - - - - - - - - - - - - - - 508
(d) Methylation with methyl iodide and a sodium
Salt in benzene or ether solution_ _ _ _ _ _ _ _ _ _ _ _ 508
(1) 3-Methyl-diacetone-d-fructose------ - - - - 508
(e) Methylation with thallous hydroxide and methyl
iodide------------------------------------ 508
(1) Methylation of methyl ox-d-glucopy-
Tanoside-------------------------- 508
(f) Quantitative determination of methoxyl groups-- 509
(1) Gravimetric method------------------ 509
(2) Volumetric method - - - - - - - - - - - - - - - - - - 510
(g) References---------------------------------- 511
8. Triphenylmethyl ethers------------------- -- - - - - - - - - - - 511
(a) Preparation of trityl derivatives--- - - - - - - - - - - - - 512
(1) Methyl 6-trityl-o-d-glucopyranoside--- 512
(b) Removal of trityl groups---------------------- 512
(1) Conversion of methyl 2,3,4-tribenzoyl-
6-trityl-o-d-glucoside to methyl 2,3,4-
tribenzoyl-o-d-glucoside------ - - - - - - - 512
(c) Quantitative determination of trityl groups---- 512
(d) References---------------------------------- 513
XVI Contents
I’age
XXXI. Methods for the preparation of certain sugar derivatives—Con.
9. Glycosidic derivatives- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 513
(a) Preparation of glycosides by Fischer method - - - - 513
(1) Methyl l-arabinopyranosides_ _ _ ! ... -- - - - 514
(2) Methyl ox-d-arabinofuranoside - - - - - - - - - 514
(b) Use of calcium chloride compounds to separate
glycosides-------------------------------- 515
(1) Methyl d-gulopyranosides - - - - - - - - - - - - - 515
(c) Preparation of glycosides from halogeno-acetyl
derivatives------------------------------- 516
(1) Methyl tetraacetyl-3-d-glucopyranoside 516
(d) Preparation of phenolic glycosides from acetyl
derivatives------------------------------- 516
(1) Phenyl tetraacetyl-o-d-glucopyranoside 517
(2) Phenyl tetraacetyl-3-d-glucopyranoside - 517
(e) Preparation of glycosides from sugar mercaptals— 517
(1) Ethyl d-galactofuranosides - - - - - - - - - - - - 517
(2) Methyl d-glucopyranosides - - - - - - - - - - - - 518
(f) Preparation of glycosides from sugars with di-
methyl sulfate- - - - - - - - - - - - - - - - - - - - - - - - - - - - 518
(1) Methyl 3-d-mannopyranoside isopropyl
alcoholate------------------------- 519
(g) Preparation of glycosides by use of alkyl iodides
and silver oxide -- - - - - - - - - - - - - - - - - - - - - - - - - - 519
(1) Methyl tetraacetyl-3-d-fructopyranoside 519
(2). Methyl ox-d-mannofuranoside -- - - - - - - - - 520
(h) References----- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 520
10. Mercaptals------------ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 521
(a) Preparation of mercaptals- - - - - - - - - - - - - - - - - - - - 521
(1) Galactose ethyl mercaptal - - - - - - - - - - - - 521
(b) References----- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 521
11. Oxidation products--- - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - 521
(a) Preparation of aldonic acids-- - - - - - - - - - - - - - - - - 521
(1) Preparation of calcium gluconate by
electrolytic Oxidation -- - - - - - - - - - - - - - 524
(2) Preparation of calcium lactobionate-
calcium bromide------------------- 525
(3) Preparation of calcium altronate and
allonic lactone by the cyanhydrin
synthesis-------------------------- 527
(4) Preparation of d-talonic acid by pyridine
rearrangement of galactonic acid-- - - - 528
(5) Preparation of potassium d-arabonate
from levulose by oxidation in alkaline
solution--------------------------- 528
(b) Preparation of dibasic acids---- - - - - - - - - - - - - - - - 528
(1) Preparation of mucic acid by the oxida-
tion of galactose with nitric acid-- - - - 528
(c) Periodic acid oxidation of glycosides_ _ _ _ _ _ _ _ _ _ _ 529
(d) References---------------------------------- 529
12. Reduction products-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 530
(a) Alcohols------------------------------------ 530
(1) Reduction of d-o'-glucoheptose with
sodium amalgam to give d-a-gluco-
heptitol--------------------------- 530
(b) Glycals------------------------------------- 531
(1) Triacetylgalactal and galactal - - - - - - - - - 532
(c) References---------------------------------- 533
XXXII. Crystallography of the sugars--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 533
1. Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 533
2. Characteristics of symmetry class 4 (monoclinic sphe-
noidal) ------------------------------------------ 533
(a) Sucrose------------------------------------- 534
(b) o-Dextrose hydrate- - - - - - - - - - - - - - - - - - - - - - - - - 540
Contents XVII
XXXII. Crystallography cf the sugars—Continued. Page
3. Characteristics of symmetry class 6 (rhombic bisphe-
noidal) --------------- - - - - - - - - - - - - - - - - - - - - - - - - - - - 541
(a) Levulose----------------------------------- 543
(b) o-Dextrose (anhydrous) - - - - - - - - - - - - - - - - - - - - - - 546
4. References----------------------------------------- 546
XXXIII. Melting points----------------- - - - - - - - - - - - - - - - - - - - - - - - - - - - 546
1. General-------------------------------------------- 546
2. Capillary-tube methods-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 547
3. Additional methods - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 548
4. References----------------------------------------- 549
PART 4.—GENERAL INFORMATION
XXXIV. Standard samples------------------------------------------ 551
1. Sucrose-------------------------------------------- 551
2. Dextrose------------------------------------------- 551
XXXV. Tests---------------------------------------------------- 551
1. Special-------------------------------------------- 551
2. General instructions to applicants for tests-- - - - - - - - - - - - 552
(a) Application for test-- - - - - - - - - - - - - - - - - - - - - - - - - 552
(b) Nature of test------- - - - - - - - - - - - - - - - - - - - - - - - - 552
(c) Identification marks- - - - - - - - - - - - - - - - - - - - - - - - - 552
(d) Shipping directions-- - - - - - - - - - - - - - - - - - - - - - - - - 552
(e) Return of apparatus-- - - - - - - - - - - - - - - - - - - - - - - - 552
(f) Address------------------------------------ 552
(g) Remittances-------------------------------- 552
3. Certificates and statements.---- - - - - - - - - - - - - - - - - - - - - - - - 553
4. Test-fee schedules--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 553
PART 5.—APPENDIXES
XXXVI. Appendix 1.-Tables 73 to 150 - - - - - - - - - - - - - ---------------- 562
XXXVII. Appendix 2.-Résumé of the work of the International Commis-
sion for Uniform Methods of Sugar Analysis----- - - - - - - - - - - - 767
1. References----------------------------------------- 779
XXXVIII. Appendix 3.−United States Customs Regulations_-_ _ _ _ _ _ _ _ _ _ _ 781
1. Regulations governing the weighing, taring, sampling,
classification, and polarization of imported sugars and
molasses---------------------------------------- 781
Index--------------------------------------------------- 799
TABLES
1. Structure of sodium lines at different intensities---- - - - - - - - - - - - - - - - - - 48
2. Optical center of gravity of sodium light sources--- - - - - - - - - - - - - - - - - - 49
3. Wave lengths of lines in the arc spectrum of sodium----- - - - - - - - - - - - - 51
4. Thickness of the normal quartz plate_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 82
5. Saccharimeter scale--------------------------------------------- 84
6. Effect of light sources on the 100° S point---------- - - - - - - - - - - - - - - - - 88
7. Saccharimeter temperature coefficient for sucrose_____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 93
8. Tolerances for polariscope tubes--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 106
9. Diameters of necks and tolerances for volumetric flasks_-_ _ _ _ _ _ _ _ _ _ _ _ 107
10. Time required for inversion of sucrose at room temperature by 0.7925
N hydrochloric acid------------------------------------------- 130
11. Variation of twice the rotation of the half-normal invert-sugar solution
with varied conditions of inversion -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 131
12. Time required at various temperatures for 99.99-percent inversion
in the presence of 0.01, 0.1, and 0.7925 N hydrochloric acid as
catalyzer----------------------------------------------------- 133
13. Measurement of the concentration coefficient of invert sugar - - - - - - - - - 134
14. Effect of salts on the rotation of invert sugar----------------------- 137
15. Influence of various reagents on the rotation of invert sugar--- - - - - - - - 137
16. Effect of Salts on the rotation of sucrose--------------------------- 139
17. Errors of analysis of sucrose caused by invert sugar- - - - - - - - - - - - - - - - - 141
323414°—42—2
XVIII Contents
18.
19.
Comparison of sucrose found by four Clerget methods - - - - - - - - - - - - - - - 146
Quantity of sample and reagents required for clarification and deleading
of beet sugar-house products-----------------------------------
. Factors for calculating invert sugar from copper oxide - - - - - - - - - - - - - - - 177
. Comparison of methods for determining reduced copper--- - - - - - - - - - - - 178
. Factors for calculating glucose by the Scales method__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 190
. Factors for various sugars for use with the modified Scales method_ _ _ _ 190
. Relative molecular reducing power (modified Scales method) - - - - - - - - - 191
. Molecular reducing power for configurationally related substances- - - - - 191
. Standards for use with the de Whalley method - - - - - - - - - - - - - - - - - - - - - 201
. Determination of monose sugar in condensed milk__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 208
. Rotatory power of commercial glucose----- - - - - - - - - - - - - - - - - - - - - - - - - 217
Constants applicable to the Browne method of analysis of sugar
mixtures----------------------------------------------------- 223
. Zerban analyses of dextrose and levulose in raw cane sugar--- - - - - - - - - 227
. Volume of milk corresponding to lactose double-normal weight_-_ _ _ _ _ _ 241
. Refractive indices corresponding to the scale divisions of the original
Zeiss immersion refractometer---------------------------------- 260
. Specific conductance (at 1,000 cycles) of potassium chloride solutions_- 272
. Arbitrarily standardized values for half-cells-------------- - - - - - - - - - - 284
. Clark and Lubs buffer mixtures, 20°C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 295
. Indicators of Clark and Lubs------------------------------------- 296
. pH values corresponding to various drop ratios- - - - - - - - - - - - - - - - - - - - - 298
. Spectral filters for 560 u--------------------------...-------------- 314
. Mercury-arc Spectral filters--------------------------------------- 324
. Computation of data for the isotherm in figures 78 and 79------------ 336
. Zerban and Sattler table for finding C and f (C) from —log T and R____ 347
. Values of k and f(k) for plane parallel cells of various thicknesses (Landt
and Witte).--------------------------------------------------- 349
. Values of k and f(k) for cylindrical beakers 26 mm and 36 mm in diam-
eter (Landt and Witte).---------------------------------------- 350
. Time required at various temperatures to form caramel equivalent to -
0.01 percent of invert Sugar------------------------------------ 398
. Hydrolysis of plant juices---------------------------------------- 400
. Quantitative data on calcium levulate precipitation - - - - - - - - - - - - - - - - - 402
. Recrystallization of levulose from alcoholic solution_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 405
Crystal size as related to sieve mesh-------- - - - - - - - - - - - - - - - - - - - - - - - 408
. Volume of sucrose crystals and of interstitial voids as related to sieve
mesh size---------------------------------------------------- 409
. Weight of crystals in relation to average grain size (screen fractions) -- - 409
51. Relation between weight and surface area of crystals for various
crystal sizes (screen fractions) ---------------------------------- 409
Optical rotation and configuration for the pyranose sugars-- - - - - - - - - 429
Differences in molecular rotation (principle of optical superposition) -- - 430
Sum of the molecular rotations (2B) for some alpha and beta derivatives
of d-glucose-------------------------------------------------- 433
. Sum of the rotations of the alpha and beta sugars in comparison with
those of the alpha- and beta-methyl glycosides (second rule of isoro-
tation).------------------------------------------------------- 433
. Molecular rotation of substances of like configuration of the pyranose
ring--------------------------------------------------------- 434
. Molecular rotation of the aldonic acids and related products---------- 435
. Rates of oxidation of alpha and beta Sugars - - - - - - - - - - - - - - - - - - - - - - - - 436
. Mutarotation of o-d-galactose------------------------------------ 445
. Equilibrium constants calculated from optical-rotation measurements,
assuming that only two isomers are present in dynamic equilibrium_ _ 447
. Thermal mutarotation for sugars exhibiting complex mutarotation---- 450
. Oxidation of sugar solutions at 0° C with bromine water in the presence
of barium carbonate-------- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 455
. Crystal forms of class 4--------- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 534
. Crystal forms of sucrose- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - 535
. Angular values between faces of sucrose crystals- - - - - - - - - - - - - - - - - - - - 535
. Refractive index of crystalline sucrose_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ --- - - - - - - - 536
. Crystal forms of dextrose monohydrate- - - - - - - - - - - - - - - - - - - - - - - - - - - - 540
. Angular values between faces of dextrose monohydrate crystals- - - - - - - 541
. Crystal forms of class 6------------------------------------------ 541
Contents
89.
90.
91.
92.
93.
94.
95.
96.
97.
98.
1öö. Hagedorn and Jensen dextrose equivalents-------------------------
iói.
102.
103.
104.
105.
106.
107.
108.
109.
110.
111.
. Angular values between faces of levulose crystals- - - - - - - - - - - - - - - - - - -
. Crystal forms of anhydrous dextrose-------------------------------
. Angular values between faces of anhydrous dextrose--- - - - - - - - - - - - - - -
. Formulas for calculating specific rotations (concentration variable) - - - -
. Rotatory power of dextrose and corrections to be applied to sacchari-
meter readings-----------------------------------------------
. Specific rotation of certain sugars at various concentrations_ _ _ _ _ _ _ _ _ _
. Rotatory power of invert Sugar-----------------------------------
. Coefficients in the Creydt raffinose formula------- - - - - - - - - - - - - - - - - - -
. Reducing-sugar values by the Munson and Walker method___ _ _ _ _ _ _ _ _
. Allihn table for the determination of dextrose______ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
. Calculation of dextrose, levulose, invert sugar, lactose, and maltose
(Quisumbing and Thomas copper equivalents)--------------------
. Bertrand table for reducing Sugars--------------------------------
. Herzfeld table for determining invert sugar in raw sugars (invert sugar
not to exceed 1.5 percent)--------------------------------------
. Determination of invert sugar by Vondrak's modification of the Herzfeld
method------------------------------------------------------
. Meissl and Hiller factors for invert sugar---------------------------
. Factors for 10 ml of Soxhlet solution to be used in connection with the
Lane and Eynon general volumetric method.---------- - - - - - - - - - - - -
. Factors for 25 ml of Soxhlet solution to be used in connection with the
Lane and Eynon general volumetric method--- - - - - - - - - - - - - - - - - - - -
. Burette readings for solutions containing 25 g of sugar sample plus
0.1 g of added invert Sugar per 100 ml-- - - - - - - - - - - - - - - - - - - - - - - - - -
. Corrections in milliliters to be added to burette readings in the titration
of lactose solutions containing three or six times as much sucrose as
lactose-------------------------------------------------------
Factors for the Lane and Eynon volumetric method for mixtures of
dextrose and levulose------------------------------------------
Zerban and Wiley factors for mixtures of dextrose and levulose (Lane
and Eynon method)-------------------------------------------
Lane and Eynon factors and reducing ratios for determination of
dextrose and levulose in raw sugars-------- - - - - - - - - - - - - - - - - - - - - - -
Milligrams of dextrose and levulose corresponding to milligrams of
cupric Oxide or copper, and reduction ratio, a, according to Erb and
Zerban, for various proportions of dextrose and levulose in the pres-
ence of sucrose (0.4 g of total sugar in 50 ml of solution), using
the Munson and Walker method --- - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Copper-levulose equivalents according to the Jackson and Mathews
modification of the Nyns selective method for levulose_-_ _ _ _ _ _ _ _ _ _ _
Ratio of levulose to total sugar from the Lane and Eynon titration and
Nyns “apparent” levulose--------------------------------------
Ratio of levulose to total sugar from the Lane and Eynon titration and
the polarization by the Mathews formula -- - - - - - - - - - - - - - - - - - - - - -
Schoorl method for the determination of reducing sugar in cane
molasses-----------------------------------------------------
Luff and Schoorl method for the determination of invert sugar in cane
Sú8*--------------------------------------------------------
Somogyi dextrose-thiosulfate equivalents---------------------------
Pot method of Main for invert sugar------------------------------
Pot method of Main for small quantities of invert sugar-------------
Sichert and Bleyer modification of the Barfoed copper acetate method
for hexoses---------------------------------------------------
Van der Haar mucic-acid equivalents of galactose-------------------
Steinhoff table for estimation of dextrose, maltose, and dextrin_ _ _ _ _ _ _
Kröber table for the determination of pentoses and pentosans--------
Apparent weight of water in air-----------------------------------
Temperature correction for glass volumetric apparatus---------------
Reduction of weighings to vacuo----------------------------------
Degrees Brix, specific gravity, and degrees Baumé of sugar solutions---
Tºº corrections to readings of Brix hydrometers (standard at
Temperature corrections to readings of Baumé hydrometers, National
#º of Standards Baumé scale for sugar solutions (standard at
562
593
594
596
596
YX
Contents
112.
113.
114.
115.
116.
117.
118.
119.
120.
121.
122.
123.
124.
125.
126.
127.
128.
129.
130.
131.
132.
133.
134.
135.
136.
Comparison of Baumé scales-------------------------------------
Density of solutions of cane sugar at 20° C___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Brix, apparent density, apparent specific gravity, and grams of sucrose
per 100 ml of Sugar Solutions--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Increase in volume when sucrose is dissolved in water at 20° C (g/100 ml) -
Increase in volume when sucrose is dissolved in water at 20° C (pounds
avoirdupois per gallon).----------------------------------------
Weight per United States gallon and weight per cubic foot of sugar
(sucrose) solutions at 20° C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Weight per United States gallon of sugar (sucrose) solutions at different
temperatures-------------------------------------------------
Volume of sucrose solutions at different temperatures--- - - - - - - - - - - - - -
Density of levulose solutions and mean density and expansion coeffi-
cients between 20° and 25° C___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Density of dextrose Solutions--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Refractive index of sucrose solutions at 20° C - - - - - - - - - - - - - - - - - - - - - -
Correction table for determining the percentage of sucrose by means of
the refractometer when the readings are made at temperatures other
than 20° C---------------------------------------------------
Refractive index of sucrose solutions at 28° C - - - - - - - - - - - - - - - - - - - - - -
Correction table for determining the percentage of sucrose by means
of the tropical model of refractometer when the readings are made
at temperatures other than 28° C-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Determination of percentage of sucrose in sugar solutions from the
readings of the Zeiss immersion refractometer at 20° C - - - - - - - - - - - -
Schönrock temperature corrections for determining refractive index
of sucrose solutions by means of a refractometer when readings are
made at temperatures other than 20° C___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Method of obtaining – log T - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Viscosity of sucrose solutions---- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Viscosity of sucrose solutions at 20° C relative to water (m/mhgo)__-_ _ _ _
Viscosity of sucrose solutions from 0° to 40° C in 5 degree intervals---
Viscosity of sucrose solutions from 45° to 80° C in 5 degree intervals —
Herzfeld table of solubility of sucrose in water at different temperatures-
Solubility of sucrose in pure water- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Velocity of crystallization according to Kukharenko, and concentration
data for pure Sucrose in water- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Solubility of dextrose in water-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Solubility of levulose in water-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Concentration data for levulose in water - - - - - - - - - - - - - - - - - - - - - - - - - -
Solubility of lactose in water - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Approximate composition of invert-sugar solutions saturated with
respect to dextrose at various temperatures (computed) - - - - - - - - - - - -
The system: Dextrose, levulose, and water at 30° C with hydrated
dextrose as the solid phase- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Influence of invert sugar on the solubility of sucrose__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Composition of solutions of maximum solubility at various temperatures
(computed)--------------------------------------------------
Elevation of the boiling point of sucrose solutions above that of water
at various vapor pressures-------------------------- - - - - - - - - - - - -
Purity factors for use with dry-lead defecation-- - - - - - - - - - - - - - - - - - - - -
International atomic weights, 1941 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Optical rotation and melting point of certain sugars and sugar deriva-
tives--------------------------------------------------------
Optical rotation and mutarotation of the reducing sugars-- - - - - - - - - - -
Corrections to be applied to saccharimetric readings of levulose solutions
When a constant normal weight is used - - - - - - - - - - - - - - - - - - - - - - - - - -
137.
138.
139.
140.
141.
142.
143.
144.
145.
146.
147.
148.
149.
150.
692
694
702
703
704
762
766
POLARIMETRY, SACCHARIMETRY,
AND THE SUGARS
By FREDERICK J. BATES AND Associates
ABSTRACT
For the purposes of this treatise, the subject matter presented has been divided
into five parts. The first of these covers a mathematical treatment of the physical
phenomena and a description and discussion of the physical equipment, such as
polarimeters, saccharimeters, and accessory apparatus utilized in the study and
applications of polarized light.
The development of polarimetric equipment is discussed from the historical
standpoint, but emphasis has been placed upon recent developments. This
phase of the subject is followed by a general discussion and evaluation of the
numerous methods for the analysis and study of raw and refined sugars and sugar
products. Special emphasis has been made upon recent contributions and appli-
cations of physical science to chemical analysis, including electrical conductivity,
colorimetry, refractometry, densinetry, hydrogen-ion concentration, turbidity
and viscosity. The latter subject includes the Bureau’s recent contributions and
important new data on the subject.
The methods of preparation and properties of the sugars and their derivatives
are given in considerable detail. In this connection a detailed study of the liter-
ature has been made and the most dependable methods of preparation of the
more important sugars and their derivatives are given.
A section of general information relating to such subjects as special tests by the
Bureau, issuing of standard samples, certificates and statements, test fees, etc.,
is included.
One hundred and fifty numerical tables are given, which provide a working
basis for experimental and analytical purposes. The data given in certain of
these tables have not heretofore been available. In table 148, “Optical Ro-
tation and Melting Point of Certain Sugars and Their Derivatives,” the data
given are the result of a careful examination of a vast literature. There are
also included the United States Customs Regulations and a digest of the Proceed-
ings of the International Commission for Uniform Methods of Sugar Analysis.
PART 1. POLARIZED LIGHT, POLARIMETERS, SAC-
CHARIMETERS, AND ACCESSORY APPARATUS
I. INTRODUCTION
Since the organization of the National Bureau of Standards in 1901
there has been submitted for test a great variety of polariscopic appa-
ratus typifying the designs and methods of construction adopted by
American and European manufacturers. The Bureau is equipped
with examples of the standard apparatus of the leading polariscope
builders, as well as special apparatus for work requiring the highest
attainable precision. For most of the apparatus sent to the Bureau
for test no intimation is given as to the degree of accuracy to be
certified. In these cases it is the practice to report the tests to such
precision as the Bureau’s previous experience with the type of appa-
1
2 Circular of the National Bureau of Standards
ratus involved has shown it to merit. On the other hand, a precision
is frequently requested which is greater than the apparatus justifies.
In general, two grades or standards of accuracy have been found
adequate in standardizing polariscopic apparatus. The first grade is
for work requiring the highest commercial accuracy. The second
grade is for all scientific work except special research in which the
precision of the supplementary data entering into the uluimate results
justifies a still higher accuracy in the polarimetric data. In the latter
case the Bureau will cooperate with investigators in providing not only
for tests of the highest precision but also, on request, in furnishing any
information at its disposal in reference to methods of measurement
and the design and construction of special apparatus. It also is the
desire of the Bureau to cooperate with manufacturers, scientists, and
others in bringing about more satisfactory conditions relative to the
weights, measures, measuring instruments, and physical constants
used in polariscopic work, and to place at the disposal of those inter-
ested such information relative to these subjects as may be in the
Bureau's possession.
II. POLARIZED LIGHT
1. NATURE OF POLARIZED LIGHT
According to the modern wave theory, light is an electromagnetic
disturbance that travels as trains of waves oscillating transversely to
the direction of propagation. The associated electric and magnetic
forces are, therefore, not only perpendicular to each other but also to
the direction of advance. Moreover, the oscillations consist, in gen-
eral, not only of very nearly periodic variations in the magnitudes
of the forces but also of more or less periodic changes in the directions
of the force vectors about the propagational axis. The variations in
magnitude for the two associated forces are generally so simply related
that, although they are 90° out of phase, it is customary in most prob-
lems related to polarimetry to consider only the variations in one
force. Since the electric force is commonly identified with the light
vector, its variations are those usually discussed in such problems.
Although the variations in magnitude and direction of this vector are
oscillatory in character, they would undoubtedly seem to possess only
the slightest indication of their intrinsic periodicity if it were possible
actually to see them as they occur in any beam of polychromatic light.
Moreover, the amplitude and period continually vary even if the light
is practically monochromatic; also even if the component in any
direction perpendicular to the propagational axis is segregated in
order to eliminate the directional variation in the unresolved oscilla-
tion. In comparison to the rapidity of the primary oscillation,
however, the variations in amplitude and period develop slowly.
For the sake of simplicity, it is customary, therefore, to consider that
both amplitude and period are constant for time intervals that are
very great compared to the period. In many cases, this makes it
possible to treat the complex oscillations of light as very simple forms
of periodic motion.
Of the possible oscillatory forms of periodic motion in a wave-like
disturbance such as light, the simplest to visualize and the easiest to
analyze are the rectilinear, circular, and elliptical. Obviously, the
last of these is the most general of the three, since in a broad sense it
Polarimetry, Saccharimetry, and the Sugars 3
includes the others as limiting cases. Whenever the magnitude and
direction of the light vector appear to vary continually in accordance
with any one of these simple periodic motions, the light is said to be
plane, circularly, or elliptically polarized, respectively. If its oscilla-
tion appears to conform only partially or not at all to any of these
forms, the light is accordingly said to be partially polarized or unpolar-
ized. Under natural conditions light as emitted by an extended
source is never completely polarized. Presumably, however, its
oscillation is always either approximately plane, circular, or elliptical
for very small intervals of time. In that case, the lack of detectable
polarization by the use of ordinary polarimetric tests must be the
result of the very rapid changes from one form of oscillation to another,
and the changes must develop in such a way that all effects of the light
are symmetrical about the propagational axis [1, p. 254]."
Since the oscillation in plane polarized light is rectilinear, the electric
vector in a beam of such light is perpendicular to a fixed plane that
lies parallel to the axis pf propagation. This plane is parallel to the
magnetic vector and is called the plane of polarization. The angular
position of this plane with respect to some chosen reference plane—
also parallel to the propagational axis—is the azimuth (YP) of the plane
of polarization. For example, if a plane polarized beam of parallel
light rays is being propagated in the positive Z-direction, and YP =0
with respect to the YZ-plane, the light vector and its oscillations
are parallel to the XZ-plane. The oscillation caused by the passage
of the wave trains of light at any point, 20, in such a beam may be
visualized as rectilinear oscillations of that point about its rest position
(for instance, a =0, y=0). While the point is thus representing
the supposedly continuous, rectilinear, and periodic variation of the
light vector, its displacement from rest position at any time, t, may
be expressed by the relation
a = a cos (azt-o). (1a)
If the light is polarized so that Yp+T/2, the oscillation is parallel to
the YZ-plane, and the displacement of the point at any time, t, will be
y=b cos (a,t–3). (1b)
These are the equations of the rectilinear oscillations obtained by
resolving the oscillation either of an unpolarized or of a polarized
beam into rectangular rectilinear components.
If the light is practically monochromatic, the amplitudes, a and b,
will be approximately constant over time intervals that are great
compared to the oscillation period, although in general both actually
vary many thousands of times a second between zero and successive
maxima of different magnitudes. The angular frequencies, o, and
a', likewise approach constancy over similar comparatively large
time intervals, although they actually vary between limits within the
spectral range of the “monochromatic” light. Moreover, these
frequencies when observed simultaneously are, in general, different
even at common points in beams which are components of a single
beam. -
c i. numbers in brackets correspond to the numbered literature references given throughout this
Ul ICUllàI. -
4 Circular of the National Bureau of Standards
Angular velocities, w, are related to the period, T, and frequency,
v, by the identities
2T 27tc
&=7– # =2xv,
where c and X’ are the velocity and wave length of the light in vacuum.
The “phase angle” constants, o, and 3, merely signify that at the time,
t=0, the displacements may not have had their maximum positive
values, a and b. As written, they are equivalent, when positive, to
lags or retardations.
The phase difference between the wave trains of the two beams,
1a and 15, is 3–0 =60 at 20 (when t=0), and a positive value for this
difference indicates that the y-train lags behind the a-train. If a, -a,
at all times, this lag obviously remains constant; but in general this
is not the case, even when the components come from a common
and practically monochromatic source. Consequently, after a time,
t, the lag at 20 becomes
At+ (2,-w,)t- (8-o)=6,-60.
However, under the above conditions relative to the source, 6,- (a),—
o,)t never increases with time indefinitely (as it would if the frequen-
cies or the components were so different that wy—w, was large and
always had the same sign); but it may nevertheless vary uncertainly
between positive and negative values of uncertain magnitude, be-
cause the difference in frequencies, although small, is subject to
erratic variations and changes in sign. Only when aſy–a, becomes
almost vanishingly small at all times will 6, remain approximately
Zel’O.
In polarimetric measurements, the differences in phase between
two component trains may be required for other common points
(or pairs of related points) along the paths traversed. The expression
for the change in the phase difference between two such points is
immediately obvious when the equations expressing the displacements
for both component beams in terms of both t and 2 are considered.
These equations are
2. – 2
Q = Q, coſ(24–6–2-ºxº)
Nº.
J–b co-(2,4- 8– 2-ºxº)
Ny
From these the expression for the difference in phase between the
Oscillations at 2, and 2, (points in y- and a beam, respectively) is at
the time, t,
2, — 2 1 1
Act,a)=6t-6 –2 | 1/ 2 22 – 2 (.-. )
(ty2) t 0 My + ( 0) Ny Nº.
The first terms, 6, and 60, have been discussed and means of making them
approach Zero will be considered later. A portion, 6a–21 (2,-2,)/Xy,
of the term in parentheses expresses the phase difference caused
when the path lengths, D, and D2, traversed by the beams are differ-
Polarimetry, Saccharimetry, and the Sugars 5
ent. Such differences appear, for example, when light passes through
doubly refracting plates and the component beams diverge. (In that
case d=D1–D9). The second portion in the parentheses expresses the
phase difference caused by a difference in the wave lengths of the
two beams which have traversed equal paths (D=D1=D). If
2. – 2, and 20=0, then 6a–0, and the whole term in parentheses
becomes simply 6p–2T2(1/\,-1/\,).
If the difference in wave length is entirely the result of a difference
between the refractive indices, p, and pz, of the medium for the two
beams, this phase difference becomes
2T2
6p–º(u,-u), (3)
since X^*=p,\;= u,\, if the component beams have the same wave
length in vacuum. That is, 6D is the phase difference introduced
between the two component beams after traversing paths of equal
length in a doubly refracting medium. This relation is used in
computing the order of thin doubly refracting plates [2, p. 554].
2. IN HOMOGENEITY OF LIGHT AND INCOHERENCY
OF LIGHT BEAMS
In the foregoing paragraphs it has been stated that the amplitude
and frequency of the oscillations, even in so-called monochromatic
light, are never constant. Moreover, the variations in these oscilla-
tion characteristics are always unlike in any two plane polarized
component beams obtained directly from an unpolarized beam.
Under these conditions, the component beams are said to be in-
coherent. That is, in strictly coherent beams, the ratio of the ampli-
tudes of the oscillations at corresponding points in the beam paths
must remain constant and the frequencies must remain equal indefi-
nitely. To say the least, the variability of amplitude and frequency
in light oscillations is closely related to the inhomogeneity of the light.
Two views of this relation may be taken, either inhomogeneity is the
cause of the variability or the reverse of this.
That light as perceived is always inhomogeneous is obvious when it
is considered that even the narrowest spectral line obtainable actually
represents an infinitude of slightly different frequencies, and that
inhomogeneity is related to variability of amplitude is suggested by
the composition of rectilinear oscillations in the same azimuth which
have constant amplitudes and constant but slightly different frequen-
cies, although, as far as light is concerned, such constancy is purely a
convenient assumption. If the displacements contributing to the
resultant at 20 and time, t, are
21 = (11 COS (oit–oi) and 3:2 = Q2 COS (22t-o),
the resultant (assuming that the displacements are additive) will be
by simple trigonometric operations
a =2|+ax+A1 cos (ot— o')—Ag sin (ot— o')=a cos (ot— oy. (4)
Chiefly as aids in the performance of these operations and in the
interpretation of the results, the following identities may be written
6 Circular of the National Bureau of Standards
A1 = (al-Ha2) cos (ab't—o.") = a cos o'"
A2= (al-a2) sin (a,'t—o.") = — a sin o’”
20=21-Hop, 20/=Q1-22, 20/= o'l-H O'2
20." = ol- og
a’=A1*-i-Agº-anº-Haº-H2a1a2 cos 2(a)'t—o.")
Ol.
o–o'+ o'", tan V-
1
4
From this it is clear that the amplitudes, A1 and A2, are periodic
functions of the time, and that consequently the amplitude a is also.
The frequency of this variation is, however, comparatively small,
since a is much greater than o'. Although a is constant, the varia-
bility of o is really the equivalent of a variable frequency in the
resultant. This simple example indicates, therefore, that both ampli-
tude and frequency of an Oscillation, which is the resultant of an
infinitude of homogeneous elementary wave trains with slightly differ-
ent frequencies, must be variable. At least this must be the con-
clusion if it is permissible to assume that any such large number of
elementary trains as is required to produce a spectral line can be
divided into two parts which yield unrelated resultants with slightly
different frequencies that approximate those of the components in the
above example. Thus if by any chance or because of any reason these
partial resultants possessed amplitudes and frequencies that varied
little during intervals equivalent to many thousand periods of the
elementary trains, their resultant would nevertheless possess all of
the frequency and amplitude variations shown during a similar inter-
val by the above simple example of a resultant. Moreover, this
conclusion applies to the two partial resultants themselves after due
consideration is given to the probable condition that the differences
between the frequencies of their components (partial resultants re-
stricted to still Smaller spectral ranges) would presumably be smaller.
If, in the case of rectangular components, it is further assumed that
the number, amplitudes, and phases of the elementary trains contrib-
uting to the y- and to the a-resultant oscillations are different, it is
obvious that there will be no relationship between the variabilities
appearing in either the amplitudes or the frequencies of the two
resultants. Hence, rectangular component beams obtained from an
unpolarized beam will not be coherent, if they are resultants of that
nature.
If the oscillations of the elementary trains contributing to the re-
Sultants were to have constant and equal amplitudes and frequencies,
so that the resultant amplitudes and frequencies would be constant,
as earlier assumed, it would follow that such trains must remain un-
broken and unchanged for time intervals at least as long as the inten-
sity of the resultant light beam appears to be unvarying. Such a
condition is undoubtedly contrary to that which actually exists, since
the innumerable oscillators that originally contribute the elementary
trains from a radiant and so-called monochromatic source are, com-
pared to the time required to obtain a simple polarimetric observation,
extremely short-lived, even though each may oscillate many thousand
times. Consequently, during each oscillation period of the resultant,
the contributions from a small portion of the oscillators cease and are
tan o'" = –1 = — tan (?- w)an (a)'t—o.").
Polarimetry, Saccharimetry, and the Sugars 7
replaced by others from freshly excited oscillators. In general, the
number, oscillation forms, phases, and to some extent the frequencies
of the replacements during a period, will differ from those of the
replaced contributions, although between averages taken over long
time-intervals these differences are not apparent. Moreover, the con-
tribution from each oscillator may change its oscillation form, etc.,
more or less gradually throughout the time interval in which it emits.
In response to these variations in the number of contributing oscil-
lators and in the oscillation form, etc., of the contributions, the result-
ant at any point in a light beam continually and compatibly alters its
Oscillation characteristics, regardless of the manner in which the
contributions arrive at that point from the source. That is, even in
light from the nearest possible approach to a monochromatic source,
the resultant oscillation will vary in a random manner through all
elliptical forms from rectilinear to circular without favor, and the
direction of the light vector at its maximum during each oscillation
will vary from period to period without favoring any azimuth. More-
over, the maximum magnitude of the vector during a period may on
occasion approach zero if the amplitudes and phases of the elementary
trains are such that almost complete interference occurs in some
segments of the resultant train. Consequently, both the amplitude
and frequency of any rectilinear component obtained from the result-
ant will also vary continually in a random manner approaching that
previously suggested, and these variations in rectilinear components
(taken at right angles, for instance) will be unlike. That is, such
components of natural light are ordinarily incoherent.
That this incoherence must exist is perhaps clearer when it is
considered that in general an oscillator contributes unequally to the
components and that this inequality varies with the oscillator. Only
when a rectilinear component of unpolarized light is further resolved
into two or more rectilinear (or elliptical) components does each oscil-
lator distribute its contribution coherently between the components
and also in the same relative degree (as the other oscillators) to any
One component. Therefore, such secondary components are coherent
as a result of artificial manipulation.
The oscillation changes, contributed to a resultant by such an
infinitude of oscillators with almost identical frequencies, develop
quite slowly in comparison with the rapidity of primary oscillation.
This comparative slowness results because the changes in the char-
acteristics of the emission of an individual oscillator develop gradually
and also because the number of replacements per period of the primary
Oscillation is small when compared to the very great number of
simultaneously contributing oscillators. It is obvious, however,
that on the average every one of this great number will be replaced
within the lifetime of the youngest. Consequently, if one of a pair
of secondary, coherent components that are plane polarized in differ-
ent azimuths suffers a relative retardation corresponding to this
time interval by being made to pass over a path sufficiently longer
than that traversed by the other, the coherency of the two com-
ponents will then no longer be evident, and the resultant light on
their recombination will be unpolarized.
The effect of this incoherency appears not only in polarized light
but also in the interference phenomenon of common light. That is,
two incoherent beams (for example, beams from different parts of
8 Circular of the National Bureau of Standards
some source) do not produce observable (so-called destructive)
interference. Likewise, observable interference is never obtained
when two primary plane polarized components of an unpolarized
beam are brought into the same azimuth and recombined. This is
the case even without introducing any path difference which would
cause incoherence. Interference effects between unpolarized com-
ponents, such as are produced from an unpolarized beam by an inter-
ferometer, occur because the component oscillations in any azimuth
and in either component beam has its counterpart in the same azimuth
in the other. Presumably, it will be only when the relative retarda-
tion between such beams becomes approximately equivalent to the
lifetime of an oscillator that all observable interference vanishes.
By using light from a suitable spectral-line source, interference effects
have been observed until the difference in path exceeded a million
wave lengths. This difference is of the order of 50 cm in air and
corresponds roughly to a time interval of one 600 millionth of a second.
Polarimetric measurements, however, are seldom concerned with
retardations which exceed a few wave lengths.
3. COMPOSITION OF RECTILINEAR OSCILLATIONS HAVING
DIFFERENT AZIMUTHS
The superposition of two coherent plane polarized beams not having
the same azimuth yields, in general, elliptically polarized light; or if
they are not coherent, unpolarized light. Ordinarily it is necessary
to consider only such beams as are polarized at right angles. Equa-
tions 1a and 1b are representative of the component oscillations
occurring at any common point, 2, in these beams. That is,
a = a cos (a), t—o) and y=b cos (w,t–8).
If the conditions that b/a, o, and w, are constant and that wº—w,-0
are approximated to a sufficient degree, the oscillations are coherent;
otherwise, they are not. For the moment it will be considered that
the coherency of the beams is a matter of doubt.
Assuming that resultant vector, r, of these oscillations is obtained
in the same manner as the resultant in the composition of forces at
right angles, it follows that
r”=a^+y}=a” cos” (a, t—o)+b” cos” (oyt–6).
By writing the identities (for comparison, see equation 4).
(a) ox-o-Ha', o, -o-o/
(b) oft-A’ – A, 3–A’ + A
(c) 6= @'t-HA - (5)
(d) a”--b°–A*-i-B” -
(e) (a”--b”) cos 26= (A*—B*) cos 26’
(f) (a”—b”) sin 26= (A*—B”) sin 26',
and then by performing the necessary simple trigonometric trans-
formations, it develops that
r”=a” cos” (act— A' +6)+b% cos” ºf-A-9) (6)
=B*-ī- (A*—B°) cos” (ot–A’--ó')
Polarimetry, Saccharimetry, and the Sugars 9
If the conditions for coherence are strictly met, A’–6' is constant
and eq 6 is the equation of an ellipse, of which A and B are the semi-
axes. Furthermore, the magnitudes of the amplitudes, a and b,
lie between those of the semiaxes. Consequently, the identity
a?– b”
A:LE=cos 2-y (7)
may be written, and it develops later that y and Y-ET/2 are the azi-
muths of the semiaxes.
If the conditions for coherence are almost met but not to the degree
essential in elliptically polarized light, A, B, 6, w, and Y are then all
functions of t, and B/A and y vary between 0 and co and between 0
and 21, respectively. The resultant light is unpolarized in this case,
and an indicator point tracing out the variations in the magnitude
and direction of the vector, r, would describe a long succession of
unrepeated patterns akin to a complicated series of almost elliptical
Lissajous figures, in which no ratio of axes or azimuth of major di-
mension is favored. Moreover, the possibility that both the major
and minor dimensions occasionally approach zero almost simultane-
ously cannot be excluded.
A similar pattern intended to represent the vector oscillations in
white light is too complicated and irregular for the imagination.
However, even in the case of a component, as obtained from a beam
of white light by an interferometer, every infinitesimal portion of its
spectrum is practically coherent with the same elementary spectral
portion of the other component. (This is true provided the previously
mentioned limitation as to the relative phase (path) difference is
imposed.) Consequently, the so-called channeled spectra appear
whenever white light is analyzed by a spectroscope after it has been
passed through an interferometer. Analogously, two rectangular
components of a plane polarized beam of white light, which are re-
combined after one has been subjected to a relative retardation of
Several wave lengths that increases with decreasing wave length, will
yield a spectrum in which every spectral element is, in the general
sense, elliptically polarized. That is, as the wave length decreases,
the Oscillation forms will pass again and again through a series ranging
from rectilinear through all degrees of elliptic to circular polarization.
Moreover, on passing through the circular form, the azimuth of the
major axis will shift from the first to the second quadrant or in the
reverse direction. Such a resultant on being passed through a prop-
erly Oriented nicol will, when examined with a spectroscope, also yield
a channeled spectrum.
Light from a so-called monochromatic source emitting a line of
average breadth (although the narrowest possible line still encompasses
an infinitude of infinitesimal spectral elements), presents no appreci-
able spread in oscillation form after being treated as suggested above
in the discussion on white light. That is, the resultant vector oscilla-
tion, even when representing all frequencies in the line, very closely
approximates a simple elliptical form. As time proceeds, however,
the ratio of the axes and their azimuths will fluctuate slightly about
average values and the major axis will occasionally approach zero.
After a sufficiently large number of periods, the representative pattern
10 Circular of the National Bureau of Standards
of this oscillation is consequently an elliptical disk (if such a represen-
tation may be allowed) which through variations in the denisty of
its shading could be made to suggest the dimensions of the approximate
ellipses occurring most frequently. Regardless of these variations,
the individual ellipses, representing the resultant oscillations of prac-
tically coherent perpendicular components, are all so nearly closed and
have so nearly the same form and azimuth that the deviations from a
perfectly stable oscillation form are negligible as far as all ordinary
problems of elliptically polarized light are concerned.
For practical purposes, therefore, it may be considered that
20/=a),—w,-0, and consequently that 26= 3– o –24. It also may
be assumed that y and the ratios b/a =tan W and B/A =tan V, are
constants, although a, b, B, and A vary. (As a matter of convenience,
it will be considered that the functions representing these ratios are
always positive.) -
From the identities (d), (e), and (f) in eq 5 it is evident that
(A*–B”)*=a++b++2a4b* cos 46 -
(a”--b”) tan 26’— (a”—b”) tan 26 e (8)
a*b* sin” 26=A*B% or sin 26= + AB/ab
The double sign in the last relation will ordinarily be neglected, since
it merely shows that sin 26 may be either positive or negative. It
can be shown by graphic methods, however, that the vector rotation
is positive (counter-clockwise to one looking toward the source, or,
that is, in the negative direction) or negative according as this sine
is positive or negative. Moreover, it can be shown that the major
axis lies in the first and third quadrants or in the second and fourth,
according as the cos 26 is positive or negative. With respect to the
position of the major axis it also appears from identity 7 that y lies
between T/4 and 3T/4 or between – T/4 and + T/4, according as as:b.
On proceeding further with the development of the relationships
existing between the identities used in the previous pages, it may be
shown that
(a)* sin 26 sin 2W =sin 2NZ
(b) tan 26' =cos 2\p tan 26
(c)* cos 2\p-cos 2) cos 2\,
(d) sin 26' =sin 26 cos 2-y
(e)* cos 25 ºn 2Y_Sin 2Y COS *—cos 26’ cos 2\pſ
tan 2 / Sin 2 / (9)
} •
, sin 2)
(f) cos 26 Tsin 27
(g) sin 2) = 1/2ſsin 2(W-Hö')--sin 2(V-6')]
tan 2\V
#: 26= ± = -.
(h)* tan 26 sin 2-y
Asterisks indicate those equations found in the Theory of Optics
[4, p. 15). However, it will be noted that Schuster used the identity
ô=6–0, as in the discussion of eq 1a and 1b.
Certain of these relationsips are required in all measurements on
elliptically polarized light, and it will be noted that after any two of
Polarimetry, Saccharimetry, and the Sugars 11
the angles have been determined experimentally, the remaining four
may, in general, be computed.
In order to appreciate that y is the azimuth of the major axis, it will
be noted that at-A/+6/=0 when rº–A*, and that (y/r)r, A, is the tan-
gent of the azimuth of the axis A with respect to axis X. It then can
be shown by the use of the previously developed relations that
b cos(6+6). (10a)
tan -
* 7"a cosó-5)
Likewise, when rº–Bº,
_(y) b sin(6'-Hö)_
tan w—(?) ,- #5-cot ^’,
where ya is the azimuth of B, also measured from the X-axis.
The direction of the rotation of the vector, r, may also be found
from the change in its azimuth Y, with time. Thus
M_b cos(a)t–6) (10b)
tan ºy,+= +=
Tyr a; a cos(a-t-o)
dyr b. a cos’Y.
dt a cos” (act—o)
or, as previously stated, the sign of the sine of the relative retardation
determines the direction of the vector rotation when a and b are
considered as always being positive.
From eq 10a, 10b, and (a), (b), and (f) of eq 9 it is evident that
^ = p, B=0, 6’ =0, and A’—ö'– a – 8, if 6=0. That is, the light is
plane polarized, and the direction of its oscillation lies in the first
and third quadrants. Many other special cases, where 0<b/a 300
and 6 has positive or negative values of various multiples of T/4,
may be analyzed easily by means of eq 5 to 10b.
sin 26
4. COMPOSITION OF CIRCULAR OSCILLATIONS
If beams of really homogeneous light were obtainable, they would,
in the general sense, always be elliptically polarized, and if their
periods were identical, their resultant would also be elliptically po-
larized in the broader sense. Within limits, the same is true in the
case of elliptically polarized and practically homogeneous real light
as long as the beams are coherent. Any beam of plane polarized
light may, as a matter of fact, be considered as the resultant of two
or more coherent beams of elliptically polarized light. However, it
ordinarily is necessary to consider only that case in which the com-
ponents of an elliptically or plane polarized resultant are two in num-
ber, and it will be assumed now that the components are circularly
polarized. [3, p. 443].
As shown by eq 6, representative oscillations of two such com-
ponents may be defined by their vectors, r1 and r2, and the contin-
ually and uniformly changing vector azimuths Y1–-E (ot— op) and
Y2==E (ot-og) where the double signs indicate that the rotations may
be either positive or negative.º. The identities y = 'y'--y" and Yo-
Y' – Y"are used to facilitate the following transformations. It will be
noted that y' is the mean azimuth of the two vectors, while 2-y” is
12 Circular of the National Bureau of Standards
the angle between them. Assuming again that the resultant vector
is found as in the composition of forces, it follows that
r”=rº-H rº–H ºrir, cos 2-y” (11)
and that
_r sin Yi-H re sin Y2
tan y = y
7", cos Yi-Hra cos Y2
where Y is the azimuth of the resultant. By writing the additional
identities
tan v=º and y = 'y'-- y’",
1
it will be found that
*T* tan "=tan (1/4—) tan Y".
1-H rº
This angle, y’’’, lies between the resultant and the mean azimuth
of the component vectors and obviously becomes zero whenever
r1=r, or y” = 0.
Since the component vectors may rotate in the same or opposite
directions, it becomes necessary to consider the two cases. If they
o' -- og _01 TC2.
//
2 ) and , 2
Consequently, the resultant and its direction are rº–rº-Hrº-H2rºr,
cos (og- oi) and Y = +(t–º")
Under these conditions, the resultant light is always circularly
polarized.
tan Y"' =
rotate in the same direction, y' = + ( at-
If the component vectors rotate in opposite directions, 3'-ºº:
and y” = + ot–º . Moreover, by substituting A * + B
and A*– Bº for 2 (rº-Hrº) and 4r, r2 and using eq 11, the resultant
and its azimuth are given by the expressions rº–B”-H (A*–B*) cos”
ol-Foº o:2–
(at- –3– 2
of the resultant with respect to the major (or minor) axis of an ellipse
representing the variations in r. Under such conditions, the result-
ant light is always elliptically polarized if r zºrs. Moreover, the azimuth
of the major axis is that of vector r when at = (oft-H ox)/2 or, what
is the same, when Y" (and, consequently, y'" also) becomes
zero. The azimuth, Y.A., of the major axis is therefore (op-oº)/2.
If the component vectors not only rotate in opposite directions
but also are equal (r1=r), it is apparent that B-0 and Y’” =0.
Therefore, r=A cos (at-º) and 3–º That is, in the
composition of circular components with different directions of rota-
tion, the resultant light is plane polarized in an azimuth determined
alone by the phase difference between the components. The roles
played by the differences in amplitude and phase are, therefore, the
reverse of those played by the same differences in the composition
of rectilinear components.
Cy e *
++ y”, where y” is the azimuth
) (see eq 6) and Y=
Polarimetry, Saccharimetry, and the Sugars 13
5. POLARIZATION BY DOUBLE REFRACTION
As already stated, natural light may be considered as being the
resultant of two or more incoherent component beams of light that
are plane polarized in different azimuths. Moreover, when the light
is actually resolved into components they are also found to be in-
coherent, and, if their planes of polarization are not exactly brought
into a common azimuth, their recombination again results in un-
polarized or partially polarized light. However, polarized light can
be obtained from natural light by resolving it into plane polarized
components and then rotating the polarization planes to a common
azimuth before the components are recombined, by diverting the
components into individual paths which are so divergent that re-
combination does not occur, or by employing some other means,
such as the nicol prism, which eliminates all but one plane polarized
component. Plane polarized light is easily produced by any of these
methods, but circularly and elliptically polarized light are not usually
obtained so directly from natural (unpolarized) light.
In general, the resolution of unpolarized (also of polarized) light
into two polarized component beams occurs naturally whenever a
beam of light traverses any doubly refracting (anisotropic) crystal.
That is, a beam of light on entering such a crystal is resolved into two
differently refracted beams, which on emergence are slightly separated
and, ordinarily, plane polarized at right angles, except when they
parallel certain unique directions in the crystals. The difference in
the refraction for the two polarized component beams is, in certain
selected directions in a number of crystalline minerals, large enough to
cause a divergence of the beams that is sufficient to allow the complete
elimination of one beam to be accomplished in various ways.
If the incident light is circularly polarized or unpolarized, the
differently refracted component beams are of equal intensity; but if it
is plane or elliptically polarized their relative intensity varies as the
crystal is rotated about the beam as an axis. If plane polarized light
is normally incident on a crystal face, the component beams (trans-
mitted by a calcite crystal, for example) are equal in intensity only
when the plane containing both refracted beams has an azimuth
^ = W-T/4 with respect to the oscillation direction of the incident light.
The ratio of the intensities for any azimuth is that of the squared
sine and cosine of that angle or, if the amplitude of the incident light
is a, the corresponding amplitudes of the components are a sin Y and
Q. COS Y.
Well-known examples of doubly refracting crystals are tourmaline,
calcite, and quartz. These examples belong to the hexagonal (or the
trigonal according to some classifications) system and to the class of
uniaxial minerals, a class which also includes crystals of the tetragonal
system. In optical terminology, quartz crystals are “positive” (or
optically prolate) [4, p. 168]. Tourmaline and calcite are both “nega-
tive” (optically oblate). These terms are concerned with the relative
velocities with which the component beams traverse the crystals in
various directions. The wave surface (any surface or surfaces of
equal phase) about a point source of light in an isotropic medium is
spherical, since there is but one velocity regardless of direction. In a
doubly refracting crystal, however, there are two concentric wave
323414°–42—3
14 Circular of the National Bureau of Standards
surfaces and, in uniaxial crystals, one is always spherical while the
other is spheroidal. The component beam corresponding to the spher-
ical wave surface traverses the crystal with the same velocity regard-
less of the path direction, and on entering (or leaving) the crystal
obeys the normal laws of refraction. The velocity of the other com-
ponent beam, as indicated by the spheroid, varies with the direction
of the path. In general, a refracted beam corresponding to the
spheroid does not lie in the plane containing both the incident beam
and the normal to the surface of incidence. The two differently
refracted component beams are therefore named, respectively, the
ordinary and extraordinary, and, in optically prolate (positive) crystals,
the velocity of the former is greater (index of refraction is less) than
that of the latter beam, while in optically oblate (negative) crystals
the reverse is true. That is, in optically positive crystals, the prolate
spheroid representing the wave surface for extraordinary beams lies
within the sphere representing a wave surface with the same phase for
ordinary beams. In the case of a positive uniaxial crystal, the spheroid
and sphere may be conceived of as having been generated by rotating
an ellipse and its circumscribing circle about their common diameter,
the direction of the major axis of the former. In a negative uniaxial
crystal, the oblate spheroid encloses the sphere, and the axis of rotation
of the generating ellipse and circumscribed circle is again the common
diameter to both, but the direction of the minor axis of the ellipse.
In both cases the direction of this common diameter is that of the
optic axis and of the vertical crystallographic axis (C-axis) of the
crystals.
If the wave surfaces for a uniaxial crystal are actually tangent at
the points of intersection with their axis of rotation, two component
beams traversing the crystal parallel to this axis will possess identical
velocities, obey the ordinary laws of refraction, and will not diverge.
Consequently, an incident beam of parallel light (polarized or unpo-
larized) will, after traversing a plate of such a crystal parallel to its
optic axis, be unchanged in its polarization characteristics. In all
other directions through the crystal the velocities are different, and
the component beams are plane polarized at right angles and diverge.
Certain uniaxial crystals (for example, quartz) rotate the plane of
polarization (or major and minor axes) when they are traversed paral-
lel to their optic axis by a beam which at incidence is plane (or ellip-
tically) polarized. This has been interpreted as showing that light,
traversing these crystals even in a direction parallel to their optic axes,
is resolved into components which have slightly different velocities
and that sphere and spheroid do not touch [5, p. 580] at their inter-
sections with the mutual axis of generation. It has been shown, more-
over, that these components are circularly polarized; or, if the waves
travel obliquely to the optic axis, the component beams are elliptically
polarized.
The wave surfaces of a uniaxial crystal are a special case of a fourth-
degree surface, which is representcol analytically by the expression
(a^+y^+2%) (a”--bºy”--cºz”)—a”(b”--c”) a’—b” (cº-La") y”—c” (a”--b”)
2*-Ha*b*cº–0, in which it may be assumed that a > b >c [3, p. 335].
Obviously, if these constants are equal, the expression reduces to
that for the single spherical wave surface of an isotropic medium (non-
crystalline materials and also many crystals of the cubic system). If
b=c only, the surface becomes a sphere within an oblate ellipsoid; or,
Polarimetry, Saccharimetry, and the Sugars 15
if b =a only, it is a prolate ellipsoid within a sphere. These special
cases apply to the so-called “negative” and “positive” uniaxial crys-
tals, respectively. If there is no equality between the constants,
neither surface is spherical, and they represent the wave surfaces of
biaxial crystals. The three sections of these surfaces by the three
principal oscillation planes (XY, YZ, and XZ), obtained by letting
2, a , and y, respectively, equal zero, are correspondingly a circle lying
within, without, and neither wholly within nor wholly without an
ellipse. In the last case the circle obviously cuts the ellipse at four
points. The diameters joining opposite intersections give the direc-
tions of the axes of single-ray velocity, which make only a small angle
with the two respective optic axes of the crystal. The angles between
these diameters and also those between the optic axes (axes of single-
wave velocity) are bisected by the coordinate directions, X and Z.
These bisectors are termed the “acute” and “obtuse bisectrices,”
according as the bisected angles are acute or obtuse. The crystal is
said to be optically negative when X, and positive when Z, is the
acute bisectrix. The XZ-plane, since it contains the optic axes, is
known as the optic plane, and the Y-direction as the optic normal, of
biaxial crystals. In the case of uniaxial crystals it may be considered
that the optic axes and acute bisectrix coincide and result in a single
optic axis. Consequently, these crystals have no definite optic plane,
and the positions of the perpendicular obtuse bisectrix and optic
normal about the optic axis are indeterminate. -
In uniaxial crystals the optic axis coincides with the crystallographic
C-axis (the so-called vertical axis), but in biaxial crystals neither of
the optic axes coincides with a crystallographic axis nor, in general,
do the coordinate or oscillation axes, X, Y, and Z. That is, in the
Orthorhombic system, the three mutually rectangular crystallographic
axes, A, B, and C, coincide with the oscillation axes, although the dis-
position of the coincidences varies with the crystal; in the monoclinic
system one of the oscillation axes (either X, Y, or Z) coincides with the
Orthodiagonal axis, B, and the other two without a coincidence lie
in the plane of the mutually oblique A- and C-axes; while in the tri-
clinic system an oscillation axis seldom actually, or even approxi-
mately, coincides with one of the crystallographic axes, which are all
mutually oblique.
As a generalization for both uniaxial and biaxial crystals, it may be
stated that when a light beam traverses them along either the X-, Y-,
or Z-axis (except the optic axis in uniaxial crystals) it is resolved into
two undiverging unequally retarded plane or eliptically polarized
rectangular component beams, and that ordinarily the beam, when
traversing them in any other direction (except those of the optic and
single-ray axes in biaxial crystals), is similarly resolved, except that
the components diverge. In uniaxial crystals, however, one compo-
nent always follows the ordinary laws of refraction, while in biaxial
crystals neither of the component beams necessarily does so.
With regard to the above indicated exceptions, a beam paralleling
the optic axis is in some uniaxial crystals resolved into two unequally
retarded circularly polarized components, while the optic and single-
ray axes of biaxial crystals are directions associated, respectively,
with internal and external conical refraction. Also, some uniaxial
(and possibly some biaxial) crystals resolve nonaxial beams into elip-
tically rather than plane polarized components.
16 Circular of the National Bureau of Standards
6. ROTATION OF THE PLANE OF POLARIZATION−PIHOTOGYRIC
EFFECTS
Most isotropic substances are “optically inactive,” or agyric; that
is, they do not normally rotate the plane of polarization when trans-
mitting polarized light [4, p. 272]. However, a large number of sub-
stances are photogyric. Possibly a preponderance of the crystalline
materials might also be included in the class of Optically inactive sub-
stances, but such a statement cannot be made definitely because too
often rotatory power of a crystallogyric material is masked by ordi-
nary double-refraction effects. In the many substances which change
the azimuth of the plane of polarization, the rotation is proportional
to the length of the light path within them. Under certain influences,
all substances may possess a rotatory power.
Substances naturally photogyric are said to be “optically active.”
Sugar solutions and essential oils are examples of isotropic substances
which are photogyric. Some of these substances are known to retain
the rotatory power in the amorphous solid state (sugar, tartaric acid,
etc.) and also in the vapor state (turpentine oil, etc.). Quartz and
cinnabar are well-known examples of crystallogyric substances, and
the first of these is exceptionally important because of its extended use
in polarimetric and other optical instruments. Even in the isometric,
or cubic, system many crystals possess a weak rotatory power.
Crystalline sodium chlorate is an example of these, and its rotatory
power is the same without regard to the direction of the light path
through it. Moreover, in spite of the masking effects of ordinary
double refraction, it has been possible of late to show that some of
the biaxial crystals also possess a rotatory power. Finally, all sub-
stances are magnetogyric, since they rotate the plane of polarization
when they are placed in a magnetic field, and when the light path
through them has a component parallel to the lines of magnetic force,
the effect is that of ordinary double refraction. In this respect an
ordinary medium in a magnetic field is somewhat similar to a uniaxial
crystallogyric mineral.
Photogyric isotropic substances are isogyric, since they have the
same rotatory power, independent of the direction of the light path
through them, while many minerals, such as quartz, are anisogyric,
since they appear to be “optically inactive” if the path direction is
normal to the optic axis, although they rotate the plane of polarization
if the path parallels that axis. These minerals are generally known
to exist in two crystallographic forms, one of which is dextrogyrate
and the other laevogyrate. These forms are also often referred to by
other terms, such as “dextrorotatory,” “right-handed,” and “positive”
crystals, in the first case, and by corresponding terms in the second.
The two forms often can be distinguished by casual inspection, and
in quartz, for instance, the form may be indicated by the oblique
striations on certain surfaces if the natural faces are reasonably intact
[5, p. 571]. These striations show that the crystals are plagihedral,
and if the striations lean to the right when they face the observer
and if the apex of the adjacent pyramid is upward, the crystal is
dextrogyrate [6, p. 31].
A dextrogyrate substance rotates the plane of polarization in a
clockwise direction to an observer looking in the apparent direction
of the source and at the clock face. That is, according to the previ-
Polarimetry, Saccharimetry, and the Sugars 17
ously chosen convention, it produces a negative rotation, although in
connection with these photogyric effects it is usually called a positive
one. Obviously, the direction of the rotation produced by a laevogy-
rate material is the reverse. Reversing the direction in which light
traverses these media does not alter the direction of the rotation.
For this reason the rotatory effect is nullified if the light is reflected
backward over its path through a naturally rotatory material. In
this respect, magnetogyratory effects are different, since these rotatory
effects are doubled when the light is returned by reflection over its
path through a material situated in a magnetic field of unchanged
direction. In other words, if the direction of the light is unchanged
and the magnetic field is reversed, the direction of the rotation is also
reversed. Consequently, the direction of the magnetorotation in a
material must be defined with respect to the direction of the magnetic
field and not with respect to that in which the light travels. If the
light, in traversing a material in a magnetic field, passes from the
South-seeking to the north-seeking pole of the magnet producing the
field, the magnetogyric effects, especially in most diamagnetic ma-
terials, are usually dextrogyrate according to the photogyric conven-
tion. In other words, the effect is apparently more often than not
dextrogyrate whenever the light travels opposite to the direction of
the magnetic force. From this it appears that the direction of the
magnetorotatory effect in diamagnetic substances (for example, glass)
is usually that of the amperian current, which would produce the
causative magnetic field if a solenoid about the light beam were used
instead of a magnet. Dextrogyric and laevogyric effects (defined with
respect to the magnetic field) are found, however, in both diamagnetic
and paramagnetic media.
In all of these photogyric effects the rotatory power of the medium
depends on the wave-length of the light. Usually the rotation in the
visible spectrum increases with decreasing wave length, but there are
many exceptions, and some media are laevogyric in one part of the
spectrum and dextrogyric in another. This change may occur
suddenly in the range of an absorption band or gradually in the region
between two such bands.
7. CIRCULARLY POLARIZED COMPONENT BEAMS IN PHOTOGYRIC
EFFECTS
It has been shown experimentally that plane polarized light, nor-
mally incident on a plate of quartz cut perpendicular to the optic
axis, is resolved into two equally intense circularly polarized compo-
nent beams which are transmitted at slightly different velocities and
have opposite vector rotations. For paths in directions between the
optic axis and its normal, it has also been found that a plane polarized
beam is resolved into two elliptically polarized components having
different velocities. However, the axis ratios of the elliptical oscilla-
tions decrease very rapidly as the direction of the path departs from
the optic axis.
Whenever plane polarized light, on entering a naturally or arti-
ficially photogyric material, is resolved into two equally intense
circularly polarized beams having opposite vector rotations and
different velocities in the material, it is obvious that at that instant
the amplitudes of the oscillations are equal, (r1=r), and the difference
18 Circular of the National Bureau of Standards
in phase must be zero. As a consequence, the azimuths of the radius
vectors with respect to the original plane of polarization are equal and
opposite. When the light emerges from an “optically active” trans-
parent plate, the amplitudes, only slightly changed, are again at least
practically equal, but the difference in the velocities of the two com-
ponent beams while in the plate has now introduced a relative differ-
ence in phase (65) which, since there is no appreciable divergence
effect, is proportional to the plate thickness, D. Consequently, the
light, on the recombination of the circularly polarized components,
is plane polarized at an azimuth
- =*T*l
with respect to the plane of polarization of the incident beams; or
'y is the change in azimuth of the emergent oscillation plane with
respect to incident oscillation plane.
If the subscripts 1 and 2 represent, respectively, counterclockwise
and clockwise oscillations, it is apparent (since on and og by conven-
tion represent positive retardations) that y represents a clockwise
rotation of the oscillation plane (and also of the plane of polarization)
whenever the component, circularly polarized in the clockwise sense,
has the greater velocity while passing through the plate; that is, Y is
negative, since oil- og. This is in accord with the experimental results,
which show that the magnetorotation in glass is right-handed (direc-
tion of amperian current) and that the clockwise oscillation is actually
as well as relatively accelerated by the magnetic field.
Some photogyric absorbing media absorb the circularly polarized
component beams differentially, and as a result the amplitudes on
emergence are unequal (riz' re). In such cases the recombined com-
ponents produce an elliptically polarized resultant, as previously
shown. This effect is usually designated as “circular dichroism.”
8. POLARIZATION OF LIGHT EY REFLECTION
A specular surface on any transparent material (for example,
glass and water) reflects light that at one angle of incidence is almost
perfectly plane polarized in the plane of incidence. As discovered by
Brewster, this occurs whenever the angle of incidence, 6, is such that
tan 0– u (the refractive index of the material). Since u varies with
the light frequency, the polarizing angle of incidence also varies ac-
cordingly. For the best results in obtaining plane polarized light by
this method, a monochromatic beam of parallel light rays and a good
plane reflector are required. Even then surface films and other im-
perfections in the reflecting surface (which may be wholly invisible)
often cause some incompleteness in the polarization. If the incident
light is plane polarized and its plane of polarization and that of
incidence are oblique, surface films cause the reflected light to be
elliptically polarized to a very slight degree (that is, tan V is small).
This method of obtaining plane polarized light is very inefficient
because only a small percentage of the incident light is reflected. To
increase the efficiency, a pile of plates (several transparent plate
reflectors in series) is used, but the results are still far inferior to those
obtained with other devices. Moreover, the deflection of the re-
Polarimetry, Saccharimetry, and the Sugars 19
flected beam causes so much inconvenience that this method is
usually employed only in demonstrational and a few other non-
precision instruments.
Regardless of the angle of incidence or number of plates employed,
the transmitted beam is never more than partially polarized if the
incident beam is unpolarized. Although undeflected, the transmitted
beam is, therefore, even less desirable than the reflected one as a source
of polarized light.
At all oblique angles of incidence other than the polarizing angle,
the reflected, as well as the transmitted, beam is only partially polar-
ized, while at perpendicular and parallel incidence there are no polar-
izing effects. This naturally suggests that the components of the inci-
dent oscillations taken parallel to and perpendicular to the plane of
incidence are reflected according to different laws. Such a difference
is provided for by the Fresnel equations [3, p. 351], which express the
ratios of the reflected amplitudes, a” and bº', to the incident, a and b,
(X- and Y-direction respectively parallel to and perpendicular to the
plane of incidence) in terms of functions of the angles of incidence,
6, and refraction, 6’. That is,
a" tan (6'-6) d b" sin (6'-6).
a `tan (YEd) * 5 Tsin (YIG)
Obviously, the square of the second ratio increases continually from
an indeterminate value to unity as 6 increases from 0 to T/2, while
the square of the first ratio decreases from the same indeterminate
value to 0 as 6 increases from 0 to T/2–6', and from this incidence
it also continually increases and becomes unity when 6–T/2. Since
a’’=0 when 6–1–6' =T/2, it follows that the reflected light is then
plane polarized with its oscillation direction parallel to the plane of the
reflecting surface. Moreover, by making use of the law of refraction,
sin 6//sin 9= u, Brewster's law for the relation between the polarizing
angle and the refractive index may be derived.
When 0 approaches T/2 (grazing incidence), the amplitude ratios
approach unity, the limiting value for no reflecting surface. At normal
incidence, 0=0, the ratios are equal (disregarding sign) because the
oscillation directions of both components are parallel to the mirror
surface. If the incident light is plane polarized and the azimuth of its
oscillation direction (X-axis in plane of incidence) is Y, then b/a = tan /
=tan Y. After reflection, the azimuth (y") of the practically recti-
linear reflected oscillation is obtained from the relation
b’’ cos 6’—6)
’’= —–= — ’’= — sº----------, tº
tan Y’’= 0// tan / tan "cos (9–1–0)
Thus at normal incidence and to an observer who always looks in the
direction (–Z) of the source both before and after incidence (the
source being, respectively, real and apparent), reflection rotates the
plane of oscillation in a manner remindful of the “from right to left.”
perversion of a reflected image and y + y^*= + r. As 0 increases from
0 to the polarizing angle, the rotation, + (y'' – Y), decreases to one-
half the value it had at normal incidence, because a” is then practically
negligible. Moreover, since cos (0–H0') changes sign at the polarizing
20 Circular of the National Bureau of Standards
angle, the rotation continues to decrease and becomes zero when
6= T/2.
The effect of the change in sign of cos (0–1–0') is the same as that
which would be caused by a sudden change from T to 0 in a phase
difference between the reflected X- and Y-components (that is, between
the oscillation corresponding to a” and bº') as 6 increases through the
polarizing angle. Moreover, if the mirror surface is of such a nature
that the light reflected near the polarizing angle is elliptically polar-
ized, intermediate phase differences are actually observable, and any
change in phase is not abrupt, since it develops more or less gradually
as incidence increases and reaches the value T/2 at or near the incidence
6=arctangent p. (The sign of the phase difference is not taken
into consideration.) Normally, the angle of incidence corresponding
to a phase difference of T/2 would be considered as the polarizing angle,
since it is then that the major axis of the oscillation path is parallel
to the mirror surface. Obviously, the Fresnel equations in the simple
form presented above must be modified for those cases in which the
reflected (and transmitted) light is elliptically polarized. The
similar expressions developed for the relation between the components
in the case of total reflection (a phenomenon which occurs only when
pºp, and after 6' (>6) reaches T/2) are examples of a relatively
simple modification [3, p. 358]. Similar expressions are also developed
for reflection from metal surfaces. In the development of the equa-
tions for such cases, the angles of refraction are treated as imaginary
or complex qualities.
In metallic reflection, the incident plane polarized light not absorbed
(some light may be transmitted if the mirror is very thin) is reflected
as elliptically polarized light at all angles of incidence except normal
and grazing. The particular angle of reflection (and incidence),
termed the “principal incidence,” 0, corresponds to the polarizing
angle of transparent reflectors in that it is defined as the angle of
incidence for which the phase difference between the components
in and normal to the plane of incidence is Tſ2. Thus at this incidence
the major axis is parallel to the reflecting surface. The angle having a
tangent equal to the ratio of the axes (B/A) of the reflected elliptical
oscillation which corresponds to this incidence is named the “principal
azimuth,” V, provided the azimuth, y, = p, of the incident plane
polarized monochromatic light is T/4(or 31/4). When these angles are
determined for a metallic mirror, the refractive index, u, and the ex-
tinction coefficient, k, may be closely approximated in many cases by
computing them from the simplified equations [1, p. 363)
k=tan 2 W.
A V1 +k”=sin 5 tan 5.
Ordinarily the characteristics of the reflected elliptically polarized
light are determined at other angles of incidence than 0. The
equations [4, p. 261] for determining up and K9 in these cases are
reduced to the forms
_sin 6 tan 6 cos 2W,
*TTE sin 2W cos 25
Polarimetry, Saccharimetry, and the Sugars 21
sin 6 tan 6 sin 2W sin 26.
*TTTEsin 2W cos 25
and require the measurement of p (the arctangent of the ratio (b"/a’’)
of the reflected components normal to and in the plane of incidence)
and 26 (the phase difference introduced between the components on
reflection). Moreover, it is assumed, as above, that the incident
light is monochromatic and polarized in a plane having the azimuth
'Y;= T/4= Wi. In consideration of relations (a), (b), and (e) of eq 9,
these equations may also be written in terms of functions of the ratio
of the axes of the reflected ellipse and the azimuth of its major axis.
_sin 6 tan 6 cos 2\V cos 2-y
*TTT-cos 2N, sin 2-y
sin 0 tan 6 sin 2V.
T 1–cos 2\V sin 2-y
K9
The coefficients, pig and kº, determined experimentally at different
angles of incidence, will vary with that angle. The relation between
coefficients, up and Ko, for normal incidence to those for any other
incidence may be simplified greatly by neglecting all squares of higher
sin” 6
2.T.2"
All 3 T K 9
powers of For most metals the resulting equations
sin” 6
*-(l tº Tº
(1 sin” 6
KO =K — 57–3–7–3.
0 6 2(u;-H k.)
are adequate in computing the coefficients at normal incidence.
As in the reflection from transparent media, surface films are dis-
turbing factors, and care must be taken to eliminate them as far as
possible if the optical coefficients of metals are determined by this
catoptric method. Under the best conditions, the method does not
yield results with an accuracy comparing to that of results obtained
by dioptric methods, but it can be used in cases where they are prac-
tically inapplicable.
9. SEGREGATION OF PLANE POLARIZED LIGHT BEAMS
(a) POLARIZERS FROM LARGE CRYSTALS
While a practically plane polarized beam of light is easily obtained
by reflection from mirror surfaces on transparent media, the method
is, as already stated, inefficient and unsuited for most polarimetric
measurements. The resolution of natural light into two equally in-
tense plane polarized beams by double refraction serves, on the con-
trary, as an ideal method of producing polarized light whenever it
is possible to segregate one of the component beams without undue
loss of intensity. In some cases this segregation is accomplished to a
degree by the crystal itself. Tourmaline, for example, not only re-
solves natural light into plane polarized beams but also absorbs them
22 Circular of the National Bureau of Standards
differentially. As a result, a plate of no great thickness (possibly 1 or
2 mm, depending on the crystal) transmits very little more than the
extraordinary beam. The oscillation direction in the extraordinary
beam lies in the plane containing both the normal to the plate surface
and the optic axis. This plane, since it is normal to the face of the
plate, is termed the principal section of the refracting surface. Ob-
viously two such plates in series with their principal planes at right
angles will almost completely absorb both components, since the
extraordinary of the first becomes the ordinary beam of the second.
Polarizers of this sort are not efficient because the transmitted
component is also reduced materially in its intensity. Moreover, the
differential absorption varies with wave length, and when complete
polarization is almost attained with a minimum loss of intensity for One
color, the intensities of other colors may in comparison be greatly re-
duced or the polarization for other parts of the spectrum may be far
from sufficient. Similar disadvantages are found in certain artificial
polarizers.
Crystals such as quartz and calcite are highly transparent for both
beams over a very great range of wave lengths. Consequently, the
production of an efficient polarizer requires only the segregation of
one of the polarized components by some artificial means which does
not materially reduce the intensity of the component. The com-
parative frequency with which sufficiently large crystals of quartz
and calcite are found has caused these materials to become very im-
portant adjuncts in all polarimetric work. The smaller divergence
between the refractive indices of the component beams in quartz has
limited the use of this material in the production of simple polarizers
for visible light. However, the difference between the calcite indices
is sufficient in some directions through the crystal to cause a com-
paratively large deviation of the ordinary and extraordinary beams.
This large divergence makes it easy to segregate either of the plane
polarized beams. In fact, such a beam of plane parallel light may be
obtained with a cross-sectional diameter equal to one-tenth the crystal
thickness simply by the proper use of diaphragms. Obviously, the
procurement of beams having the cross section (or aperture) often
required would necessitate the use of unduly large crystals. Conse-
quently, Nicol took advantage of the differences between the refractive
indices for the two beams to effect the total reflection of the ordinary
beam at an interface formed by a cementing material with an inter-
mediate index, and he thus devised a type of prism which greatly in-
creases the aperture obtainable at the expense of a comparatively
slight loss of intensity. Of the various modifications of this prism,
some have so nearly the form of the original cleavage crystal that the
direction of the optic axis, the principal plane (section) of the faces,
and consequently, the direction of the oscillation may be determined
approximately by simple inspection.
In a calcite cleavage rhombohedron, the X-direction is the optic
axis and makes equal angles with the three edges at either of the two
fully obtuse corners formed by the cleavage surfaces. These edges
include three facial angles of about 101°55' at these corners, and the
optic axis makes an angle of about 63°44' and 45°23’ with each edge
and face, respectively. When light is incident normally on a face, the
ordinary ray (direction of the ordinary beam) passes directly through
Polarimetry, Saccharimetry, and the Sugars 23
the rhomb, as in the case of an isotropic plate; but the extraordinary
ray, although deflected, is so directed that a plane containing both
rays parallels the optic axis. This plane is the principal optic plane
(or section) of the transmitting faces. The principal section for the
artificial faces of a nicol prism are similarly determined, and the oscil-
lation directions of the extraordinary and ordinary beams lie, respec-
tively, in and perpendicular to it.
(b) POLAROID
Polaroid, which is a polarizing 'material in sheet form, consists
of submicroscopic needle or thread-like pleochroic crystals of herapa-
thite [7]* (iodoquinine) embedded in a suitable matrix, such as cellulose
nitrate or acetate, and all oriented in the same direction. It may be
produced in almost any size desired. According to the patent speci-
fications (U. S. Patent 1,951,664), it may be made in the following
Iſlä.Ill.) GI’.
Quinine bisulfate (1.5 g) is dissolved in 50 ml of methyl alcohol,
brought to a boil, and stirred while adding 0.525 g of iodine as a 20-
percent solution in alcohol. Stirring is continued while a jell forms
and until the mass has cooled. The herapathite is rapidly precipitated
out of the solution as a jelly of interwoven submicroscopic needles.
This jelly is then incorporated in a viscous suspending medium, such
as a solution of cellulose nitrate or acetate dissolved in amyl or butyl
acetate or other suitable solvent, and stirred until uniformly dispersed
throughout. By pouring or flowing a viscous medium of this char-
acter, the mechanical forces acting upon the crystals are such that the
crystals all turn until their long axis is substantially parallel to the
direction of flow. The flowing in some cases is accomplished by ex-
trusion through a long thin die (U. S. Patent 1,989,371) or by flowing
past an edge (U. S. Patent 2,041,138). In either case, a flat ribbon-
like sheet is obtained, having the crystals all oriented in the same
direction. The crystals then behave approximately as a single large
crystal the full size of the sheet. The active layer is protected by
exterior layers of the cellulosic material or by glass plates.
In the central part of the visible spectrum, the polarization is about
99.8 percent complete, but at the ends of the spectrum, both in the
extreme violet and in the extreme red, the polarization is not nearly
so good [8]. This results in a faint residual purplish tint in the field
instead of blackness when two pieces of Polaroid are accurately crossed,
when using an intense white-light source.
In certain applications of polarized light, Polaroid is the equal of
the nicol prism and in some cases is superior. It has opened up new
fields of application to which the nicol prism is not adaptable.
For one class of work, however, at least in the present state of the
art, the nicol prism still has no serious rival, namely in those appli-
cations where nearly complete extinction is required, as in precision
polarimetric measurements. Here complete polarization is required,
and any unpolarized light seriously interferes with the precision of
the measurement.
* This substance was named in honor of its discoverer, William Herapath, who studied this material from
the Standpoint of making polarizing apparatus from it. He was able to obtain single-crystal polarizing
plates }} inch or more square, which he believed would soon entirely supersede the nicol prism and the
tourmaline plates then in use (1852) as polarizing media.
24 Circular of the National Bureau of Standards
For most applications where a bright field or an interference pattern
is used, Polaroid is optically as good as a nicol prism and has the
advantages of being very thin and not being limited to a comparatively
small free aperture, as is the nicol. Instead of displacing the nicol
prism, Polaroid finds its most useful and satisfactory applications in
those very cases for which the ordinary polarizing prism is least satis-
factory or is inadequate. The two polarizing mediums are thus
supplementary to each other.
Polaroid is finding use in strain detectors and analyzers, in three-
dimensional moving pictures, in removing glare for photographic
purposes, and in education. Laminated spectacle lenses containing
a film of Polaroid are being used in sun glasses for use both on land and
on water, the Polaroid removing glare to a large extent. Being
comparatively cheap and rather startling in some of the effects that
may be produced, it is serving to arouse public interest in the phenom-
ena of polarized light and its many uses in everyday life.
(c) METHODS OF LOCATING THE PLANE OF POLARIZATION
The extraordinary beam is transmitted by practically all modifica-
tions of the nicol; but even so, it is in many cases relatively difficult
to determine the position of the principal plane, especially if there is
some doubt concerning the type of the nicol in question. In such
cases, the approximate direction of the oscillation is easily determined
by using a plate of glass as a reflecting polarizer and the nicol as the
analyzer to extinguish the light thus polarized. That is, the direction
of oscillation in any light that would be transmitted by the prism
lies in the prism section which coincides with the plane of incidence
to the reflector when the nicol is set to extinguish the plane polarized
reflected light, and that section is the principal section of the nicol if it
transmits the extraordinary beam.
Under the very best of conditions, it is possible to set a simple nicol
with a very satisfactory precision in the position for the extinction of
plane polarized light. These conditions are, however, seldom realized
in the performance of polarimetric measurements. Consequently,
in order to increase the precision of the setting, the simple nicol has
been so modified (or used in combination with a half nicol) that two
half-fields rather than a practically uniform field appear. In many
cases, these modifications (described elsewhere in detail) may be used
either as polarizer or analyzer, although their use as polarizers is, with
certain exceptions, considered preferable, and even necessary, in some
polarimetric instruments. As polarizers these special “halfshade
nicols” produce, in effect, two parallel and almost equally intense
beams of plane polarized light with their oscillation directions mutually
inclined at a small angle. In making observations, the simple
analyzing nicol, instead of being set for extinction, is so adjusted
that its polarizing plane divides this very acute angle between the
oscillation planes of the two parts of the polarizer and at the same time
makes the corresponding half-fields appear equally intense. If the
beams from the polarizer are equally intense, the polarizing plane
of the analyzer bisects the angle between their oscillation directions
for a matched setting.
Many of the generally used types of halfshade nicols, and espe-
cially those composed of a full and half nicol, do not yield the
Polarimetry, Saccharimetry, and the Sugars 25
equality of intensity required to cause this bisection of the half-
shade angle at match to an exactitude that is within the precision
of a setting on matched fields. That is, the polarization plane of
the analyzer set for match always lies closer to the oscillation
direction of the beam with the more intense maximum than it does
to that of the beam with the less intense. The magnitude of this
deviation from actual bisection is precisely determined with difficulty,
and there is consequently always some uncertainty concerning the
actual positions (azimuths) of the oscillation directions of the two
beams from a halfshade polarizer with respect to any chosen reference
plane. Fortunately, in simple polarimetry, which is concerned
chiefly with rotations of the plane of polarization, this uncertainty
has no significance. In other cases, especially if they involve ellip-
tically polarized light, it may be so troublesome that it is necessary
to use a type of halfshade nicol that transmits two beams of the same
intensity. Even then it is advisable to use the halfshade as the
analyzer and the simple nicol as the polarizer, since it is obvious that
the analysis of the elliptical polarization produced by any agent
of unknown characteristics will be simpler if that agent acts only on
a single uniformly plane polarized beam of light with a definitely
known azimuth. In general, however, the use of a “halfshade” as an
analyzer makes it more difficult to produce the necessary sharpness
of division between the half-fields.
In measurements on elliptically polarized light, it is usually not only
necessary to know at all times the precise relative angular position of
the principal plane of the polarizer with respect to the bisector of the
angle between the principal planes of the analyzer, but it is also
necessary to determine with great precision its angular position with
respect to other directions or planes, such as the direction of lines of
electric or magnetic force, the planes of incidence of mirrors, or the
principal planes of crystalline plates that are being tested or used as
auxiliaries. For this reason it is always desirable, and sometimes
necessary, to mount not only the analyzer but also the polarizer in
circles that are so constructed and graduated that the nicols may be
rotated through 360° and that any rotations may be measured to
0.01° or less. When such circles are a part of a combined polarim-
eter and spectrometer, some of the methods which have been used
for determining the azimuth of the principal plane of the polarizer
with respect to some reference direction in the instrument are easily
employed.
In the M’Connel method [9] for setting the polarizer at a known
azimuth, it is well to remove the polarizer temporarily from the
collimator circle, since that nicol and the glass prism or plate (used in
alining the axes of telescope and collimator perpendicular to the vertical
axis of the polarimetric spectrometer by the Gauss eyepiece method),
together with its supporting table, are replaced by an auxiliary nicol
prism mounted in a suitable holder that fits the table mounting.
This auxiliary nicol with its axis and the common axis of telescope
and collimator alined is set so that its principal plane (approximately
located as described above) makes a small angle with the vertical axis.
The halfshade analyzer (its telescope at this stage being focused on
the halfshade field and not as in the alinement tests for parallel light
coming from the collimator) is then set for a match on the plane
26 Circular of the National Bureau of Standards
polarized light being transmitted from the collimator by the auxiliary
polarizer. After obtaining this setting, the circle of the prism table is
rotated through 180°, so that the auxiliary nicol is reversed end for
end, and a new setting of the analyzer is made. It is clear that the
difference between the settings taken before and after the reversal is
double the Small deviation of the principal plane of the polarizer from
the vertical axis. Consequently, a setting midway between these
settings will yield a match on plane polarized light only when the
principal plane of the polarizer contains the vertical axis. The
auxiliary nicol is therefore removed and the collimator polarizer is
replaced in its circle and rotated until the match for that setting of
the analyzer is accomplished. This gives the polarizer setting on its
circle for zero azimuth of its principal plane, and with this setting
known, any other desired azimuth can be obtained to the degree of
precision afforded by the sensitivity of the halfshade system and the
analyzer and polarizer circles.
Polarization by reflection at the polarizing angle of incidence from
specular surfaces on transparent materials has also been used [10, 11]
to determine the position of the polarizer for zero azimuth. When
the reflecting surface of the glass alining prism or its equivalent
contains the vertical axis and its polarizing angle of incidence is
known, the setting of the analyzer corresponding to zero azimuth of
polarizer is easily obtained by an analyzer match on light reflected at
that incidence. For this test the incident monochromatic light may
be either polarized or natural; but if it is plane polarized, the azimuth
of the principal plane of the collimator nicol with respect to the plane
of incidence must not be too small, since the intensity of the reflected
light will then be so low that a match setting of the analyzer is
impossible.
When the polarizing angle of the reflector is unknown, it, and also
the zero azimuth, may be determined with a precision approximating
that of procuring an analyzer match if a series of observations is
made for two or more azimuths of the polarizing nicol and at two or
more angles of incidence for each azimuth. The azimuths (not
exactly known) of the polarizer's oscillation plane with respect to the
plane of incidence should be equally distributed above and below zero
but not so near that observations are difficult. The angles of inci-
dence should be chosen in about equal numbers on each side of the
only approximately known polarizing angle and should not depart
from it by more than a few degrees except in preliminary observations.
When the observations (angles of incidence and analyzer settings for
match) are plotted, the curves (almost straight lines for a narrow
range near polarizing incidence) will intersect at the polarizing angle,
and the analyzer reading corresponding to this incidence is the analyzer
setting for matching on light polarized in the plane of incidence.
Although a graduated collimator circle for the polarizer is advan-
tageous, it is obvious that none of these methods require this, since
all necessary azimuth readings may be referred to the analyzer circle.
Moreover, once the analyzer setting for light polarized in the plane of
incidence is obtained, the polarizing spectrometer may be moved
about and used to set the principal plane of polarizers in other instru-
ments with respect to vertical, provided the spectrometer is supplied
with adequate leveling devices, which assure a coincidence of its
axis with that direction.
Polarimetry, Saccharimetry, and the Sugars 27
10. PRODUCTION OF ELLIPTICALLY POLARIZED LIGHT
(a) BY DOUBLY REFRACTING PLATES
Doubly refracting plates for the production and compensation of
elliptically polarized light can be prepared from either uni- or bi-axial
crystals. Strained plates of isotropic materials, since they show the
so-called “accidental double refraction,” are also often used in polari-
metric instruments instead of crystalline plates.
Doubly refracting plates from uniaxial crystals are usually cut
parallel to the optic axis. Consequently, a beam of plane polarized
light normally incident on such a plate is, in general, resolved into
two undiverging plane polarized components, the extraordinary with
its oscillation plane parallel to the optic axis (X- or Z-axis, depending
upon whether the crystal is optically prolate or oblate) and the
ordinary with its oscillation plane parallel to the optic normal.
If the plate is from an optically oblate crystal, the extraordinary
component traverses it with the greater velocity, u,<uo. If by
convention the direction of the faster oscillation is chosen as the
reference direction in the plate, the optic axis (X-axis), parallel to
that direction in this case, should for convenience be marked “fast.”
In the case of plates from optically prolate crystals, u, u, and the
optic axis (Z-axis) is the direction of the slower oscillation and should
be marked “slow.”
If the amplitude of the incident rectilinear oscillationis “a”, and its
azimuth with respect to the fast axis of the plate is Yo, the amplitudes
of the components in, and perpendicular to, that axis are a cos Y, and
a sin Y, at incidence. Neglecting loss by absorption and reflection,
the amplitudes are unchanged on emergence from the plate, but a
phase difference proportional to the plate thickness, D, will have
been introduced between the oscillations, which were obviously in
phase at incidence. According to eq 3, and since 2=D, this phase
difference, 6,-2TD(u,-us)/X=öp (in an optically oblate plate, for
example), and in eq 5 to 9, it is the equivalent of 26. Moreover,
according to identities of the preceding eq 8, the ratio of the ampli-
tudes a sin Ypſa cos Y,+tan Y,+tan W. When 6, and iſ are known,
the characteristics of the resultant elliptical oscillation may be deter-
mined from eq9.
To determine 6, with the needed accuracy usually requires some
precise method of calibration, but its approximate value can be
computed from D and the refractive indices if the crystal and the
manner in which it was sectioned to produce the plate are known.
Moreover, since the difference between the indices increases in gen-
eral with decreasing wave length, it is usually necessary to determine
6, at several points in that portion of the spectrum in which the plate
is to be used.
Such doubly refracting plates are used chiefly as accessories for
polarizing microscopes and for such polarimeters as are used in
measurements on elliptically polarized light. These accessory plates
are usually rated in terms of the phase difference (or relative retarda-
tion) which they introduce between components having some desig-
nated wave length.
Although the relative retardation, especially when small, is more
commonly expressed in circular degrees (or possible radians), the
equivalent number (N) of wave lengths may also be used to designate
28 Circular of the National Bureau of Standards
the “power” of a plate. For example, a plate having a thickness
such that it causes a relative retardation of 360° (2T radians) between
components having a wave length X' may be termed “a wave plate
for X’,” or if the relative retardation is only 90°, the term “quarter-
wave plate” is generally employed. When the relative retardation
is even smaller, the terms “10° elliptic compensator” or “4° elliptic
halfshade” (as examples) are often used to designate not only the
power of the plate but also its purpose.
Serviceable doubly refracting plates may be made from almost
any sufficiently large, transparent, anisotropic crystal, provided the
difference in the refractive indices for the plane polarized component
beams is not so great that a plate producing the required relative
retardation is too thin and fragile. For example, a wave plate
cut from calcite parallel to the optic axis would be quite thin, and
since N=6,ſ2T = 1 for a wave plate, the thickness can be computed
from the relation D=X//uo-pe. For a calcite plate cut in such a
manner, the difference in the indices is about 0.172 for sodium light,
and consequently D is roughly 0.0034 mm. In the case of quartz
(optically prolate) un-po-0.0091 approximately for sodium light,
and for a corresponding wave plate cut parallel to the optic axis,
D is roughly 0.065 mm.
Mica, a monoclinic (pseudohexagonal) crystal, is much used in
making doubly refracting plates (especially those having very low
relative retardations). This follows because its perfect basal cleav-
age, giving thin elastic sheets, makes it relatively easy to prepare
fairly uniform plates of considerable area and of almost any needed
thickness. The acute bisectrix (X-axis) of this mineral makes an
angle with the normal to the plate (basal cleavage) surface that ranges
between 0° and 2°, depending on the specimen, while the angle between
the optic axes is about 70°. The Z-axis is consequently the oscilla-
tion direction of the “slow” component and the Y-axis that of the
“fast”, and the corresponding refractive indices may be used for com-
puting the approximate thickness of mica wave plates. While these
indices vary considerably with the specimen, their difference for
sodium light is of the order 0.004, and D for a wave plate at that wave
length is consequently about 0.14 mm. Accordingly, the thickness
of a mica quarter-wave plate for sodium light is about 0.03 mm [5,
p. 352], and of a 2° halfshade, about 0.0008 mm. Some of the thinnest
mica halfshades used show the brilliant first-order interference colors
by reflection in white light. -
When designed for use as accessories, thin doubly refracting plates,
or even thick ones not made of comparatively hard crystals, should be
mounted in Canada balsam between glass cover plates, unless the
nature of the measurements requires other mounting materials. The
cover plates should obviously be free from strain, since otherwise the
“accidental” double refraction modifies the power of the enclosed
plates. This modification can be particularly disturbing, since it is
seldom uniform over the plate aperture. Multipel reflection between
the surfaces of the plate or of its covers is another factor which some-
times causes certain annoying modifications in the performance of the
plate. In many cases the first of the multiple images may become
brighter than the primary image as the “matching” of a halfshade
field is approached, and a setting for “complete” extinction is im-
possible if the images coincide.
Polarimetry, Saccharimetry, and the Sugars 29
Tilting a doubly refracting plate with respect to the light beam
changes the effective order of the plate. Consequently, when the
measurement undertaken depends on previous or independent calibra-
tions of such a plate, it is necessary to maintain the light beam normal
to the plate unless the tilting is controlled and made a part of the
measuring procedure. Finally, in very precise measurements by cer-
tain methods, it may be necessary to consider other factors (tempera-
ture effects, for example) which might affect the order of a plate to a
degree not compatible with the desired precision.
(b) BY ELECTRIC AND MAGNETIC FIELDS
Besides doubly refracting crystals and strained media, metallic
reflection has also been mentioned as producing marked elliptical
polarization. Because of their theoretical significance rather than
their practical importance in polarimetric measurements, mention
should also be made of the elliptical polarization effects observed when
media in magnetic and in electric fields are traversed perpendicular to
the lines of force by polarized light. The Zeeman effect is another
condition which should not be passed without mention, because in this
particular case polarized light is apparently emitted by a source. The
effect is observed when incandescent vapors emitting line spectra are
placed in strong magnetic fields. Lines unpolarized under normal
conditions of emission are so affected under the influence of the fields
that they are resolved into polarized component lines by a spectro-
scope. In the simplest of many more or less complicated effects, there
are two oppositely rotating circularly polarized component lines when
the source is viewed along the lines of magnetic force, and three plane
polarized component spectral lines when the viewing is at right angles.
As compared to the normal unpolarized spectral line, the component
circularly polarized in the direction of the amperian current produc-
ing the magnetic field is decreased in frequency, the other is increased.
On the same basis of comparison, the central plane polarized com-
ponent (oscillation plane parallel to the magnetic force) is unchanged
in frequency, while the other two (oscillation planes perpendicular to
the force) suffer the same changes in frequency as the circularly
polarized components.
11. MEASUREMENTS ON ELLIPTICALLY POLARIZED LIGHT
From eq 5 to 10 it is obvious that in order to determine the oscilla-
tion characteristics of a given beam of elliptically polarized light, it is
necessary to measure two out of the four following elements of the
representative ellipse. These determinative elements are the ratio
(tan V) of the minor to the major axis; the azimuth (Y) of the major
axis with respect to some chosen reference plane; the ratio (tan W)
of the amplitudes of the rectangular rectilinear oscillations which are
obtained when the elliptical oscillation is resolved into plane polarized
components in and parallel to the same reference plane; and the phase
difference (26) between such components. If the elliptical polariza-
tion is produced from a plane or elliptically polarized light beam by
some agency such as a doubly refracting plate, it is obviously neces-
sary to determine not only the characteristics of the emergent light
but also those of the beam incident on the plate. Moreover, the azi-
323414°–42—4
30 Circular of the National Bureau of Standards
muth (yo) of the principal plane of that plate with respect to the
reference plane must also be known. In general, therefore, there are
five measurements which must be made. In addition, the location
of the chosen reference plane may require several measurements, as
already shown.
The apparatus for the determination of these various elements consists
of a polarizer for producing the oscillation form of the incident beam
and an elliptic analyzer capable of yielding such measurements as
may be required to analyze the oscillation characteristics of both the
incident and emergent beams. When combined, the resulting instru-
ment is adapted for practically any required polarimetric measure-
ments on a polarized beam with any definite oscillation form from
plane to circular. Such an instrument is, therefore, essentially a
universal polarimeter.
(a) ELLIPTIC POLARIZERS AND HALFSHADES
Very often the polarizer is simply a nicol prism. In such a case
tan V, - 0 if yº–0. However, the polarizer usually is set in such a
position with respect to the principal plane of the doubly refracting
plate under investigation that + y = T/4 or 3T/4. In that case, this
Pºp! plane is the reference plane and Y,+0. Moreover, tan Wi- == 1
8.I) 6;=0.
In some cases the polarizer consists of a nicol followed by a quarter-
wave plate, which is so set that it produces circularly polarized light,
which may have either a right or left vector rotation. With this
device, Yi, at incidence on a second plate, is obviously undeterminate,
while V = Wi-T/4 and 26, = T/2.
Seldom is there any advantage in using incident beams that are
other than plane or circularly polarized, unless an elliptic halfshade
following the nicol is introduced. In such cases the incident beam is
divided into two parts, with different ellipses representing their polar-
ization. The axis ratios of these ellipses may be practically equal or
different. When equal, the vector rotations in the two parts of the
beam are opposite. When the ratios are different, that for one part
of the beam is generally zero and that for the other is small. Usually,
with such halfshades, the azimuths, Yi, for both parts of the beam are
practically that of the light emerging from the polarizing nicol.
Balanced halfshades produce the condition in which the axis ratios
for the two parts of the beam are equal, and the Bravais [1, p. 348]
biplate is an example. The Brace elliptic halfshade [12] is an example
of the unbalanced type.
(b) ELLIPTIC ANALYZERS
The elliptic analyzer usually consists of an elliptic compensator and
a following nicol prism, while in some cases an elliptic halfshade is
introduced between these parts rather than in the polarizer. More-
over, the simple nicol is sometimes replaced by a split (halfshade)
nicol. The use of both halfshades divides the field (or beam) into
four parts which must be matched in intensity for an analyzer setting.
Except during initial adjustments in the assembly of the analyzer,
the elliptic halfshade is bound to the nicol and does not rotate inde-
pendently. However, both the compensator and the nicol must be
capable of independent rotation. A universal analyzer containing the
three parts has been designed and described by Skinner [13].
Polarimetry, Saccharimetry, and the Sugars 31
(c) ELLIPTIC COMPENSATORS
Various kinds of elliptic compensators have been used but, in gen-
eral, these may be divided into two classes—variable- and constant-
order compensators. (The order of a compensator or halfshade is the
relative retardation it produces, expressed in wave lengths.) Well-
known examples of the first type are the Babinet and strain compensa-
tors. It seems that the first of these was designed by Babinet merely
to detect elliptically polarized light and was later adapted by Jamin
for use in actual measurement. A more or less detailed description of
this compensator can be found in most texts on physical optics, and
an excellent example of its use is found in Drude's Investigation of
the Optical Constants of Metals [14, 15].
With the original form of Babinet compensator, the use of an
elliptic halfshade is not feasible because the field of view presents a
series of bright and dark bands, which are indicative of the compensa-
tor order in the different parts of the beam and which are shifted
when the ellipticity of the light is changed. With the Soleil modifica-
tion it is, however, possible to use an elliptic halfshade because, in
effect, each band is so broad that it covers the whole field, which there-
fore presents a practically uniform intensity.
The strain compensator also presents a field of uniform intensity
and is often used in conjunction with an elliptic halfshade. Such a
compensator consists of a plate of glass (or other suitable transparent
isotropic material) which is so mounted that it may be subjected to
positive and negative compressions in a direction perpendicular to the
light beam and in the desired azimuth. Within reasonable limits,
the relative retardation of such a compensator is proportional to the
compression. -
The quarter-wave plate (Senarmont's compensator) and the Brace
elliptic compensators, which have much smaller orders, are examples of
fixed-order compensators. These are both adapted to use with elliptic
halfshades. In fact, high precision of measurement with any uniform-
field compensator depends on such use. With such combinations a
sensitivity has been claimed which permits, under best conditions, the
detection of a change in axis ratio equal to 0.0001.
(d) FUNCTIONS OF ELLIPTIC COMPENSATORS AND HALFSHADES
The usual function of a compensator is to restore elliptical polariza-
tion to plane polarization. A quarter-wave plate compensator or its
equivalent is obviously capable of so reducing any elliptical polariza-
tion, simply by making either the fast or slow axis of the compensator
to coincide with the major axis of the light oscillation. The positions
of the compensator axes in such complementary settings yield the data
required to determine Y for the major axis. Moreover, the azimuths
of the oscillation planes of the resultant plane polarized beams,
corresponding to the two complementary settings, may be determined
by the analyzer nicol and the major axis bisects the acute angle between
these planes. This acute angle is, therefore, equal to 2V.
If the order of the compensator is less than a quarter wave, it will
reduce elliptical oscillations to plane polarized light only when 2W =26,
the order of the compensator expressed as angular retardation. (See
eq 9a, where, if 6 is replaced by 6., it is evident that the maximum V
for a given 6. is reached when W = T/4 or 3T/4 and, therefore, when
sin 26–sin 2W).
32 Circular of the National Bureau of Standards
As with the quarter-wave plate, there are complementary settings of
the compensator, each of which results in plane polarized light and
yields its own particular nicol setting. The Stokes method [16] uses
these four settings (two of the compensator, C, and C, and two of the
nicol, N, and N2) for determining not only Y and V but also 26., if the
compensator is uncalibrated.
With the nicol and compensator only, it is impossible to determine
when the latter has fully reduced (or compensated) the elliptical
polarization. The function of a balanced elliptic halfshade is to
indicate by a matched field when this compensation is complete.
That of the unbalanced halfshade is similar, except that it indicates
when the axis ratio of the oscillation leaving the compensator has
reached a small definite value. As in ordinary polarimeters, the
function of the nicol halfshade is to increase the precision of settings
on the major axis of the plane (or the practically plane) polarized light
emerging from the compensator.
Three different designs of the apparatus for determining C, C, N,
and N, are possible. That is, the nicol and compensator may be borne
on circles or verniers that rotate independently, a rotating circle which
carries the nicol and also a rotating vernier for bearing the compensa-
tor, or the relation of nicol and compensator to circle and vernier may
be reversed. This last design was that used by Stokes. Conse-
d ( C, + C.)
3. 2
quently, according to his metho — Tſ4 gave the reading
which would make the axes of the compensator and ellipse coincide.
Moreover, if Cº-C-c and N3–N1=m are written, and if a balanced
tan n, sin m.
+ and cos 2\pi = −. • If an un-
tan C SII). C
balanced halfshade is used, these formulas must be modified. The
modified forms have been developed by Tuckerman [17] and by
Skinner [13].
halfshade is used, then cos 26.-
12. REFERENCES
[1] P. Fº Theory of Optics, English ed. (Longmans, Green and Co., London,
1902).
[2] E. Edser, Light for Students (The Macmillan Co., New York, N. Y., 1927).
[3] T. º Theory of Light, 3d ed. (The Macmillan Co., New York, N. Y.,
1901).
[4] A. Schuster, Theory of Optics (Edward Arnold, London, 1904).
[5] R. W. Wood, Physical Optics, 3d ed. (The Macmillan Co., New York, N. Y.,
1934).
[6] N. H. Winchell and A. N. Winchell, Optical Mineralogy (D. Van Nostrand
Co., Inc., New York, N. Y., 1909).
[7] W. B. Herapath, Phil. Mag. [4] 6, 346 (1853); 7, 352 (1853).
[8] M. Grabau, The Optical Properties of Polaroid for Visible Light, J. Opt.
Soc. Am. 27, 420 (1937).
[9] J. C. M’Connel, Phil. Mag. [5] 19, 317 (1885).
[10] R. M. Emberson, J. Opt. Soc. Am. 26, 443 (1936).
[11] J. R. Collins, Rev. Sci. Instr. 9, 81 (1938).
[12] D. B. Brace, Phys. Rev. 18, 70 (1904).
[13] C. A. Skinner, J. Opt. Soc. Am. & Rev. Sci. Instr. 10, 491 (1925).
[14] P. Drude, Ann. Phys. Chem. [3] 34, 489 (1888).
[15] P. Drude, Ann. Phys. Chem. [3] 39, 481 (1890).
[16] G. G. Stokes, Phil. Mag. [4] 2, 420 (1851).
[17] L. B. Tuckerman, University Studies of University of Nebraska 9, 157 (1909)
Polarimetry, Saccharimetry, and the Sugars 33
III. MEASUREMENT OF ROTATION IN CIRCULAR
DEGREES
1. POLARISCOPES WITH CIRCULAR SCALES
(a) HISTORY OF DEVELOPMENT
About the year 1669 Bartholinus [1] discovered the double refrac-
tion in Iceland spar. A few years later the polarization of light was
first noticed by Huygens [2] while repeating Bartholinus’ experiments,
but the phenomenon remained an isolated fact in science for more
than a century afterwards. In the period 1766 to 1777 M. l'Abbé
Alexis Marie Rochon [3], using doubly refracting prisms, perfected
a device for measuring small angles with a precision 0.1 of 1 second.
With this apparatus, constructed of rock crystal, he measured small
angles, such as that subtended by the diameter of a planet, and with
a similar one constructed of Iceland spar, he measured the diameter
of the sun. His device consisted of a prism cut from a doubly re-
fracting crystal in a direction to give maximum separation to the two
rays. In addition to producing an angular separation of the two
rays, the prismatic effect spread each of the rays into its spectrum.
This latter being undesirable, Rochon added another equal glass prism
in reverse position to achromatize the prism. He thus obtained un-
º
A.
A B
FIGURE 1.-Rochon’s double-image prism, indicating diagrammatically how the
eaſtraordinary ray diverges when the prism is constructed of calcite, A, and of quartz
or rock crystal, B.
colored images and still retained the angular deviation between the
two differently refracted rays.
He later found that more nearly perfect achromatism was obtained
if the second prism was made of the same material as the first but
cut in such a direction that the light passed through it along the
optic axis, i.e., the direction of no double refraction.
In one form of Rochon's micrometer, this acromatized prism was
placed in the tube of his telescope in such a manner that it could
be moved back and forth along the axis of the telescope. The tele-
scope was sighted upon the object to be measured and the two images
brought just into contact by movement of the prism along the tele-
scope axis. The constants of the prism and its position in the
telescope gave the value of the angle being measured.
Rochon appears to make no mention of the fact that the two rays
produced by his prism are polarized. It is probable that he knew
this to be true but was not particularly interested in that fact. He
was an astronomer and navigator and used his device for astro-
nomical and nautical measuring instruments. However, before he










34 Circular of the National Bureau of Standards
died in 1817, Rochon had the satisfaction of seeing his device used
with great success by a young confrère named Arago, for an entirely
different purpose, for the study of polarized light.
About 1808 Malus [4] discovered, accidentally, that light when
reflected from the surface of glass, acquires properties similar to
those possessed by light transmitted through a plate of a doubly
refracting crystal, i.e., it is not the same in all directions around the
line along which the ray is traveling, but appears
to be two-sided, or “polar”; hence the term
“polarization.”
M This “two-sideness” of light may be detected

by allowing it to fall upon another plane glass
plate set at a proper angle. By maintaining the
plate at the polarizing angle and rotating it
around the beam, the reflected light is seen to
- vary in intensity as the plate is rotated, and in
one position of the plate the reflected light vanishes
“LLLP” altogether.
Arago [5], in 1810, discovered the rotation of
the plane of polarization of polarized light. He
noticed that when quartz, cut perpendicular to
l the optic axis, was placed between the two in-
clined plates, the position at which the light
vanished was different from that when nothing
was between the plates. Arago used Rochon's
achromatized doubly refracting prism to good
advantage in his studies on polarized light. The
7 glass plate of Malus served as a polarizer, while
N Rochon's prism served as the analyzer, not only
for Arago but later also for Biot. Biot might well
be called the father of polarimetry, since it was
he who worked out the fundamental physical laws
upon which modern polarimetry is based.
F $ Biot [6], in 1812, discovered the proportionality
IGURE 2–Diagram & º -
jjaj.n. ii. of the rotation to thickness. The apparatus
trate the principle of designed by Biot about 1814 for studying polari-
polarization by re- zation in general is shown in figure 3. The
ſººd by polarizer, M, was a black mirror set at the polar-
M and N izing angle and whose mounting, B, could be
adº; rotated about the axis of the tube, T. B', which
jº.º.º. could also be rotated about the axis of the tube,
about the axis. T, carried the mounting, C, upon which the sample
being studied was placed so that it could be
turned in any direction. The light from white clouds of the sky
was observed through the analyzer which consisted of an achroma-
tized double-image rhomb of calcite (Rochon prism) mounted upon
a divided circle.
This prism, in general, produced two beams, one of which being
undeflected was used, while the other, being deviated by an amount
depending upon the angle of the doubly refracting prism, was disre-
garded. This probably was the forerunner of the nicol prism, since
it seems only another step to make the separation of the two rays so
great that one would be entirely lost from the field of view. In fact,
ºrrº
Lºrr"
Polarimetry, Saccharimetry, and the Sugars 35
when the nicol prism was invented in 1828, its inventor described it
under the title, “A method of so far increasing the divergence of the 2
rays in calcareous spar that only one image may be seen at a time.”
For studying the rotation of the plane of polarization in liquids, Biot
replaced the tube, T, by supports to carry a tube closed with glass
end-plates in which the liquid was placed. His original apparatus
was described in 1811–17 (6, 7, 8). In 1840 he described [9] certain
modifications of his more general instrument, together with explicit
precautions in using it for measuring the rotation of optically active
liquids.
'ºing the period 1815–40 Biot formulated practically all the
fundamental laws of polarimetry in use today. He recognized the
FIGURE 3.−Ome form of Biot's original apparatus.
g
difference between rotation produced by crystalline structure and that
produced by substances when they appeared to have no crystalline
structure, i. e., liquids and dissolved substances. The latter he
believed to be due to the molecules themselves. He also recognized
that each different kind of optically active molecule had a different or
characteristic rotatory power. This, within the limits of his experi-
ments, he found to remain the same regardless of whether the substance
was in the solid, liquid, or vapor state. In order to have a comparable
basis for the purpose of comparing the rotatory power of different
kinds of molecules, he calculated from the observed rotation of each
substance the rotation for unit length and unit density. This he
called “molecular rotation” or “molecular rotatory power” because it
had to do with the molecule rather than crystal structure, and he
represented it by the symbol [o]. By his definition of [a] for the case
of º substances, [o]=o:/density Xlength or using present-day sym-
bols, o/pl.
In the case of solid substances dissolved in inert liquids, he defined
[o] as
100 × rotation 1000. 100 a. 12
|*|†weight %)Kdensity Xlength OI’ ( ppl or -º (12)
In these equations, o is the observed rotation in circular degrees, p
the density, l the length in decimeters, p the grams of dissolved sub-

36 Circular of the National Bureau of Standards
stance per 100 g of solution, and c is the grams per 100 ml of solution.
It is the hypothetical rotation produced in unit length by 1 g of the
active material dispersed in a volume of 1 ml, which in present day
nomenclature, is termed “specific rotation.” Molecular rotation is
the hypothetical rotation produced in unit length by 1 gram-molecule
of º active material dispersed in (or condensed into) a volume of
1 ml.
This work of Biot appears to have been the foundation of all polar-
imetry. From this time on, rapid strides were made in the improve-
ment of apparatus, and there resulted the science of Polarimetry as
we know it today. A few years later, the polarizing plate of black
~ 24° -
EXTERNAL FIELD
FIGURE 4.—Original form of the nicol prism.
A, Diagrammatic sketch; B, detailed sketch of limiting rays (1 and 2) and of the various angles. DAC and
BCA are right angles.
glass and the achromatized calcite analyzer rhomb had been replaced
by the nicol [10] prism, previously mentioned, which was a far more
effective and convenient device for polarizing light than the glass
plate. It consisted of a rhomb of Iceland spar cut diagnonally and the
two pieces cemented together in such a manner that one of the doubly
refracted rays is reflected to one side, and the other passes on through
the prism.
(b) TYPES OF POLARIZERS (FIG. 6) AND POLARISCOPES (FIG. 7)
The simple polariscope of Biot was improved by Mitscherlich [11]
and by Wentzke [13], one of whom appears to have been the first to
use two nicols, and by Robiquet [12] who added the Biquartz of Soleil
[14], thus making the setting dependent upon the transition tint
(tiente de passage), and many others. Some transition tint instru-
ments are still in use.
In 1856 Pohl [15] attempted to increase the sensitivity of the simple
polariscope by the use of a mica halfshade, but was not entirely


Polarimetry, Saccharimetry, and the Sugars 37
successful. However, his idea was later satisfactorily developed by
Laurent [16]. In 1845 Soleil [14] had invented the quartz—wedge
compensating system and added it to the polariscope, thus laying the
basis for the modern saccharimeter.
In 1860 Reverend William Jellet [17] described the first satisfactory
halfshade polariscope. The utilization of the halfshade principle
was the first important step in the perfection of the modern instrument.
Prior to this, with the exception of the Soleil biguartz transition tint
plate, both the polarizing and analyzing devices were simple nicol
prisms, the “end point” being determined by setting the instrument
for a minimum of light intensity in the field. Jellet's contribution
introduced into polariscope design the photometric field. To con-
struct his halfshade device, which he used as the analyzer, he selected
a rhomb of Iceland spar several times longer than its other dimensions,
and squared off the end faces. He then sliced the resulting prism
parallel to its long dimension, BS’ and at a small angle, SCD, to
the short diagonal D'D of the end faces (as indicated in fig. 6A),
reversed the two pieces end for end, and cemented them together
(fig. 6B). In this manner he obtained a compound prism (shown
in cross section in fig. 60) whose principal crystallographic section
A/C in one half made a small angle to that (CA) in the other half,
the principal crystallographic section of each half being equally
inclined to the short diagonal of the end face. Diaphragms were
placed centrally at each end of the prism. One ray (the ordinary
ray O' and 0) came straight through, while the other (the extraor-
dinary E' and E) was deviated slightly in each half and diaphragmed
out. Thus the light in one half of the field was polarized in a plane
making a small angle (about 2°) with the plane of polarization of the
light in the other half of the field.
In 1870 Cornu [18] improved upon Jellet's idea by removing a wedge-
shaped section from a nicol prism and recementing the two halves.
Thus the plane of polarization in each half of the field made a small
angle with that in the other half, as in Jellet's prism.
Schmidt and Haensch [19] simplified Cornu's prism by removing
the wedge-shaped section from one half only of the nicol prism, the
three pieces then being cemented together as before. In mounting,
the divided half was placed toward the analyzer, and each part of
this half gave light vibrating in a plane, which made an angle equal
to the angle of the removed section, with the plane of vibration of the
light coming from the other part. This angle is known as the half-
shade angle. The field of the instrument thus appears divided into
two parts, and the setting is made by turning the analyzing nicol
until the parts become of equal intensity. The sensitivity of the
instrument depends on the magnitude of the angle of the halfshade.
As the angle diminishes, the precision with which a setting can be made
increases. However, the total illumination of the field diminishes
with the halfshade angle. An angle of about 2.5° is the minimum
working value for ordinary conditions of measurement.
The advantage of the halfshade principle was universally recognized,
and a number of halfshade polarizing systems were introduced by
various investigators. Three of these, the Laurent, the Lippich, and
the Jellet-Cornu as modified by Schmidt & Haensch, have been
extensively used by polariscope builders.
38 Circular of the National Bureau of Standards
r N
S - N T N Le E
% As/HAs/#5.
S º N f T N ſº E
N [−l is-
++)/ s 7 ti-Hz s/{}}{-e
Q W
s ki N T P N L2 E
}{}/st/ H / /i/ ºli,
FIGURE 5.—Graphic representation of steps in the early development of saccharimetry.

Polarimetry, Saccharimetry, and the Sugars 39
A, (1669) The simple calcite rhomb (Bartholinus).
B, (1783) Rochon’s double-image prism.
C, (1808) Malus, polarization by reflection.
D, (1810–11) Arago’s discovery of the rotation of the plane of polarization. As a
polarizer, he used a plate of glass, and as an analyzer, a calcite prism, achroma-
tized with a piece of glass, operating upon the principle of Rochon’s double-
image prism with which Arago was familiar.
E, (1815–17) Biot's discovery of the proportionality of the rotation to thickness
and concentration, and the formulation of the physical laws upon which modern
polarimetry is based. He used apparatus similar to Arago’s, placing his solu-
tions in a metal tube closed with glass end plates or cover glasses. G represents
the glass plate; T, the tube; and R, the simplified Rochon prism.
F', (1827) Nicol's prism, by which one of the polarized rays (as in the Rochon prism)
is eliminated from the field.
G, (1842). Mitscherlich, also Wentzke, improved upon Biot’s apparatus by using
nicol prisms as polarizer and analyzer, and using various arrangements of
lenses, and applied it in the sugar industry.
H, (1845) Soleil’s biguartz or sensitive tint plate was added, giving a divided field
in which the setting of the instrument was made by matching the colors of the
two halves of the field at the “sensitive tint” point.
I, (1845) Soleil’s double quartz-wedge compensator was added, enabling white
light to be used and laying the foundation for the modern saccharimeter. In
G, H, and I, S represents the light source; N, nicol prisms; T, the tube containing
the sugar solution; Li and L2, lenses; E, the observer's eye; P, a quartz plate;
Q, Soleil's biguartz; and W, Soleil’s quartz-wedge compensator.
40 Circular of the National Bureau of Standards
When plane polarized light of more than one wave length traverses
an optically active substance, it emerges with the vibration planes
of the individual waves all inclined to each other in a sort of fan-
shaped arrangement, the violet waves having been rotated through
the greater angle. An analyzing nicol, on being rotated, will cut out
D
FIGURE 6.-A, B, and C, Jellet’s halfshade device which made the setting dependent
wpon matching intensities of the light in the halves of the polariscope field; D,
Lippich-type halfshade device.
each wave in turn, but it is impossible to darken the field owing to the
fact that some portion of the light from each of the remaining waves
passes through the analyzer. If the polarizer be of the divided-field
type, it will be found impossible to darken either half of the field,
and color will always be present. Thus, in all polariscopes in which

Polarimetry, Saccharimetry, and the Sugars 41
the setting is made by rotating the analyzing nicol, it is necessary
that the light source be monochromatic, or at least nearly so.
(1) LAURENT AND JELLET POLARIZERs [16,17].—Of the three half-
shade polarizing systems mentioned above, the Laurent alone is
limited to the use of one single monochromatic source. In this system
a half-wave plate, usually a thin plate of quartz cut parallel to the
optic axis, covers one-half of the field of the polarizing nicol. In order
that the two rays traversing the doubly refracting quartz can combine
to give plane polarized light on emergence, they must have an optical
difference of path equal to one-half wave length. Thus, the thickness
of the quartz must always be such as to bring this condition about,
and this form of halfshade can be used only with a light source giving
the particular wave length for which this condition is fulfilled. The
angular position of the new plane of polarization is slightly different
from that of the polarizing nicol, and the conditions for a halfshade
are thus established. The advantage of this system is due to its
adjustable sensitivity; the halfshade angle, being twice the angle
between the optic axis of the plate and the plane perpendicular to the
principal section of the polarizer, can be readily varied by rotating
the polarizer. Inasmuch as the Laurent polarizer requires a mono-
chromatic source, it is seldom combined with a quartz compensating
system. The Jellet polarizer, described above, has a fixed halfshade
angle, and therefore the sensitivity cannot be varied. Its advantage
lies in the fact that it does not easily get out of adjustment, and does
not, in itself, require the use of monochromatic light.
(2) LIPPICH SYSTEM [20].-In the Lippich polarizing system, the
halfshade angle is formed by two beams of plane polarized light which
come from two separate nicols, one of which covers but one-half of
the aperture of the other (fig. 6D). If these two nicols are turned
until the vibration planes of the light which they transmit coincide,
they act as a single nicol (with some reservations). If one of them
be rotated through any angle, a halfshade angle is formed equal to
that angle. Because of the ease with which the halfshade angle can
be varied, as well as the high degree of perfection attained by the
opticians in constructing the prisms, we have in the Lippich an
adaptable and sensitive polarizing system. The accuracy with
which a setting can be made is increased to the extent that the dark
dividing line between the halves of the field can be made to vanish.
With a broad source of light this condition is very nearly attained in
the Lippich. It does not in itself require the use of a monochromatic
SOUITCé.
(3) SENSITIVE-STRIP SYSTEM.–In 1903 Brace [21] described the
sensitive-strip spectropolariscope. In the ordinary nicol prisms the
extraordinary ray is utilized. It occurred to Brace that it was possible
to reverse this condition and use the ordinary ray. Thus, instead of a
film of liquid between two large pieces of Iceland spar, he proposed
using a thin piece of spar immersed in liquid and placed in a cell with
glass ends, the plate of Iceland spar covering the entire field and
being inclined at an angle of 70° to the axis of the system. To obtain
a polarizing system similar to the Lippich, it would be necessary to
place a second cell with a narrow strip of spar covering one-half of
the field, in the position ordinarily occupied by the small nicol of a
Lippich system. If such a system could be perfected, it would have
many advantages over the Lippich. Among these may be mentioned
42 Circular of the National Bureau of Standards
FIGURE 7.-Early polariscopes.
Boit's apparatus as modified by Wentzke.

Polarimetry, Saccharimetry, and the Sugars
43
Figure 7 (Continued.)—Early polariscopes.
2. Mitscherlich, 3, Duboscq, 4, Laurent; 5, Lippich; and 6, Landolt.

44
Circular of the National Bureau of Standards
FIGURE 7 (Continued).-Modern polariscopes.
Upper, Gaertner; lower. Hilger.

Polarimetry, Saccharimetry, and the Sugars
FIGURE 7 (Continued).-Modern polariscopes.
3, Schmidt & Haensch;4, Fric; 5. Laurent type (Jobin & Yvon).
323414°–42 5

46 Circular of the National Bureau of Standards
the saving of Iceland spar and rectilinear passage of the light through
the system. In addition, great sensitivity would be secured because
a practically vanishing line would be obtained between the halves of
the field, as the small strip of spar need not be over 0.1 mm thick.
The device was perfected and used by Bates, who subsequently suc-
ceeded in combining the two cells into one. The Brace sensitive-strip
spectropolarizing system is the most sensitive yet devised. However,
it is rather fragile, and its use is not recommended except in work
requiring the highest obtainable precision.
(c) TESTS OF POLARISCOPES WITH CIRCULAR SCALES
Polariscopes with circular scales will be accepted for test (see
test-fee schedule 421, p. 553). A thorough examination is given
all optical parts. The scale will be checked for as many points as
desired.
(d) NATIONAL BUREAU OF STANDARDS EQUIPMENT
Polariscopes with circular scales for measuring absolute rotations
are now made by most polariscope builders. The National Bureau of
Standards is fortunate in having a large Schmidt and Haensch pre-
cision instrument with a silver scale reading to 0.001°. The Lippich
polarizing system is unusually good, the larger nicol having an avail-
able opening of 15 mm. The instrument is mounted on a cast-iron
base 1 m in length. Owing to the necessity for accurately controlling
the temperature while measuring rotations, a large air thermostat,
consisting of a wooden box 40 by 55 by 60 cm covered with asbestos,
is mounted between the polarizing and analyzing systems. Access
is had to the interior by means of a small door in the side. The room
in which the instrument is located is thermostated at a temperature
approximately 1 degree lower than is desired in the polariscope air
bath. An electric heater then brings the bath temperature up to the
proper point and maintains it there. The heater is made of fine
resistance wire wound around a large framework which fits inside
the box. See figs. 26 and 27, p. 100–101. The current is controlled by
means of an electronic relay operated by a mercury contact, which in
turn is operated by toluene contained in a series of glass tubes so
constructed and placed as to give a maximum change of volume in
a minimum of time when a small temperature change takes place.
The air is kept constantly stirred by a small fan. The temperature
remains constant to 0.01° C. No mechanical relay of any kind is
used, and consequently there is no trouble from relays sticking.
A large Weiss electromagnet, figure 8, equipped with a suitable
polariscope is available for the study of magnetic rotation. This mag-
net is cooled by water circulation, thereby permitted continuous
use even when heavy currents are employed.
2. LIGHT SOURCES FOR CIRCULAR-SCALE POLARISCOPES
(a) GENERAL
In accordance with the rapidly increasing use of polarimetry in
commercial and scientific work, there has arisen a demand for greater
accuracy. The largest source of error in precision measurements is in
the light sources. The production and utilization of suitable light
Sources is by far the most difficult problem with which the polari-
Polarimetry, Saccharimetry, and the Sugars 47
scopist must cope, and it therefore receives continuous study at this
Bureau. For many years any sodium source was considered suitable
for this work. Then came the so-called light filters of Lippich [22]
and Landolt [23]. These filters, however, are open to two severe criti-
cisms: (1) The efficiency of the purification is a function of the in-
tensity of the source, and (2) the available light is reduced by absorp-
tion in the liquids used in the cells.
Subsequently, spectrum filtration came into use for precision work.
In this method, light from an intense source is passed through an
optical system containing a dispersing medium, and only the desired
wave lengths are permitted to enter the polariscope.
Figure 8.-Large electromagnet for studying magneto-optical effects.
(b) SODIUM
(1) FLAME.-Until recently the sodium lines have been the one
intense source with which a large percentage of the precision work
has been done. This source has been used for determining practi-
cally all of the polarimetric constants, including the standardization
of quartz control plates. Unfortunately, the two sodium lines are
difficult to separate from the remainder of the spectrum, and as the
flame is intense there is danger of one or the other of the lines reversing.
In 1906 [24] a careful study of spectrum lines as light sources for polari-
metric work was made at this Bureau. It was found that the lack
of intensity, the high dispersion necessary for purification, the presence
of other lines of considerable intensity in the neighborhood of D, and
D2, as well as the unstable line structure under certain conditions,
render this source far from satisfactory. Owing to the great precision

48 Circular of the National Bureau of Standards
required in present-day polariscopic measurements, intensity is of
paramount importance. Even in commercial instruments the half-
shade angle is generally not over 10 degrees, which means that the
polarization plane of the analyzing nicol is prac-
tically at right angles to the planes of the polarizing
system and less than 1 percent of the light is
transmitted. Thus only a very small fraction of
the incident light ever reaches the eye of the
observer. After an extensive investigation, the
Bureau has found that for an intense sodium flame
source the best results are obtained by feeding
}} some form of fused Na2CO3 into an oxyhydrogen
flame. In utilizing this source a rod of this sub-
stance is placed in the flame at one of the positions
shown in figure 9. The line structure of the
sodium lines obtained by this method was studied
with an echelon spectroscope. The lines were
found to be extremely sharp and to differ from the
arc spectra by the absence of the characteristic
haziness in the edges of the lines. If displace-
ments as large as 5 A had occurred, they would
Figure 9. Oxyhy have been readily detected. The broadening was
drogen sodium fiame at all times symmetrical. In this respect the
studied at the Na: observations agree with the more recent work of
§ fireau * other observers, but are contradictory to the results
0.70,0,0,7°C.S. obtained by Ebert [25], which have been accepted
in polariscopic work. By careful manipulation of the flame in posi-
tion 3, reversals of the lines took place, D2 preceded Di in this respect.

TABLE 1.-Structure of sodium limes at different intensities
Width in angstrom units
• Relative Position 3
Spectrum line intensity * , 8. & 8 &
POSition 1 ||POSition 2
Nago O3
melting Na2CO3 melting
slowly very rapidly
D1-------------------------------------- 1. () 0.08 0.2 3 to 4 4 6
D?-------------------------------------- 1.6 . 08 ... 2 13 to 4 1 6
1 Reversed.
It is thus evident that so far as their line structure is concerned, the
sodium lines can be depended upon to give a sufficiently definite
optical center of gravity up to the point of reversal in position 3
(fig. 9). However, very noticeable variations in polariscopic measure-
ments are likely to be observed with sodium sources at different
intensities. These variations, it is believed, are not due to changes in
the line structure of the source, but to the difficulty of excluding all
impurities in the light, even with a very narrow slit and a dispersion
sufficient to separate D, and D2. This extraneous light constitutes a
different percentage of the total illumination whenever the intensity
of the source varies. It may, therefore, appreciably change the optical
center of gravity, thereby giving a different apparent rotation when
Polarimetry, Saccharimetry, and the Sugars 49
the field appears dim than when it appears bright. Aside from the
color and stability of the sodium lines up to reversal, there is little in
their favor as a polariscopic source. The flame requires the constant
attention of an assistant, and even in reversal the intensity is not
nearly sufficient to permit the use of the greatest sensitivity of a good
polarizing system. The sodium flame sources have been summarized
by Landolt [26] in table 2.
TABLE 2.-Optical center of gravity of sodium light sources, Landolt [26]
e & e Effective
Source of light Purification wave length
A.
Bunsen flame with NaBr---------- 10-cm layer of 9 percent K2Cr2O7 in water- - - - - - - - - - - - - 5920. 4
Bunsen flame with NaCl- - - - - - - - - - 10-cm layer of 9 percent K2Cr2O7 in water - - - - - - - - - - - - - 5894. 8
Burner with NaCl or NaBr. - - - - - - || Lippich filter, K2Cr2O7 and U(SO4)2- - - - - - - - - - - - - - - - - - - 5893. 2
Sodium---------------------------- Prism purifications lines D1 and D2 only - - - - - - - - - - - - - - 5892. 5
Landolt lamp with NaCl---- - - - - - - 1.5-cm layer of 6 percent K2Cr2O7 in water------------- 5889. 4
Bunsen flame with NaCl-- - - - - - - - - 10-cm layer of 9 percent K2Cr2O7 in water and 1-cm 5889, 1
layer of 13.6 percent CuCl2 in water.
Landolt lamp with NaCl---------- Unpurified-------------------------------------------- 5880. 6
Various types of sodium lamps have been designed to give the
greatest possible intensity consistent with a minimum of attention.
In the Pribram [27] lamp, fused salt in platinum boats is exposed to a
Bunsen flame. When the supply in one boat is exhausted, the boat
is withdrawn and a second containing a fresh supply is quickly intro-
duced. Fairly constant illumination is obtained for a long time. In
the Schmidt & Haensch lamp, fine platinum wires are bent and in-
serted into a spoon, the melted salt being drawn up to the point
by capillarity to the hottest portion of the flame. In the Landolt (28)
type, a Muencke burner (Bunsen lamp with conical wire-gauze top
and sufficiently strong air supply to cause the inner dark cone of the
flame to disappear) is used. Exposed to the flame are two heavy nickel
wires, around the middle of which nickel gauze is wrapped. The gauze
is charged by immersing in melted salt. An intense flame is obtained.
The Zeiss lamp is a simple and convenient type. Pumice stone
saturated with salt is exposed to a Bunsen flame. The position of the
pumice stone with respect to the flame is important and is easily
controlled by means of a thumbscrew. For a very intense sodium
flame the method of molded sticks of fused sodium carbonate pre-
viously described, is the best.
(2) ELECTRIC SoDIUM LAMP.-Two forms of electric sodium lamps
with somewhat different characteristics have recently become avail-
able. They are the General Electric sodium vapor lamp [29] made
in this country (fig. 10A), and the Osram sodium vapor lamp [30]
made in Europe (fig. 10B).
The General Electric lamp must be run from a special transformer
housed in the base. The bulb has considerable area which is uni-
formly illuminated. It must be used on alternating current and is
rated at 60 watts.
The Osram lamp, on the other hand, has a comparatively small
working area but has a higher intrinsic brightness. It is constructed
to operate either from alternating or from direct current (not both,
however, as the electrodes are somewhat different in the two types).
It uses about 1.4 amperes and may be plugged directly into the power
50
ircular of the National Bureau of Standards
- - - - - -
Hº ºfflº
Figure 10.-Electric sodium lamps.
A. G. E. sodium lamp; B, Osram sodium lamp.



Polarimetry, Saccharimetry, and the Sugars 51
line in series with a suitable rheostat only. Its shape makes it par-
ticularly adaptable for use in front of a collimator slit. The General
Electric lamp is the more suitable where a broader source is required.
Neither lamp gives light consisting of the two sodium D lines alone.
While in the light there is very little of the continuous spectrum
background which is always present in flame spectra, yet these sources
cannot be used without proper purification, as there are four other
doublets in the sodium arc spectrum which are ordinarily not observed
in the flame spectrum, as shown in table 3:
TABLE 3.−Wave lengths (in angstroms) of lines in the arc spectrum of sodium
[The figures in parentheses refer to the relative intensities of the lines as given in “Lines in the Arc Spectrum
of the Elements” [31]]

5154 (6)
5149 (6)
4983 (6)
5688 (8) 4979 (6)
616I (8)
5682 (8)
6155 (8)
D1=5896 (10)
D2–5890 (10)
In many cases light filters may be used successfully, but where
ºn rotation measurements are required, spectral purification is
In 662Cl6 Ol.
The rigorous requirement as to purity may to some extent be
realized when it is known that a quartz plate, which reads approxi-
mately 40.000° for D1 (5896), will read about 40.100° for D2 (5890).
If one is attempting to read to 0.001°, or even to 0.01°, it is obvious
that the purity of the light is of much greater importance than has
generally been realized.
(c) MERCURY LINES
For the production of the so-called yellow-green line of mercury
(A=546.1 mp) several types of lamps are available. In all of them,
advantage is taken of the fact that mercury vapor, heated to incandes-
cence by an electric current in a vacuum, gives an intense line spectrum.
The most important lines, in Angstrom units, and their relative in-
tensities are given [31] as 6908 (10), 5790 (10), 5769 (10), 5461 (10),
4916 (6), 4359 (10), 4078 (8), 4047 (8). Some type of optical disper-
sion system must be resorted to in order to separate the desired line.
At this Bureau the fused-silica mercury lamps originated by Heraeus
are used. They may be obtained in almost any desired shape. The
straight Uviarc types are particularly convenient. Owing to the
relatively high melting point of fused quartz, they can be safely
operated at high intensities without water-cooling. Great care must be
exercised not to permit the radiation from these lamps to enter the eyes
without first passing through protective glasses.
The yellow-green line of incandescent mercury vapor, A=5461, was
proposed by Bates [24, p. 243) as the standard source for all accurate
polariscopic work. Quartz mercury-vapor lamps as now made are
reliable in action. If sufficient care is exercised in preparing the
mercury and exhausting the lamps, the characteristic mercury lines
Only will be obtained in the visible spectrum and with great intensity.
Different observers have found markedly different line structures
for the line X=5461 A, depending upon the method of analysis em-
ployed. The map in figure 11 was obtained with the echelon with 1.8
amperes passing through the lamp. The fractional values given are
52 Circular of the National Bureau of Standards
the relative intensities as nearly as they could be estimated. It was
found impossible to decide whether the satellite, -0.24, belongs to the
positive or negative side of the primary. When the current was
increased to more than 2.1 amperes, the satellite, -0.55, increased in
intensity until it about equaled the primary. The difference in wave
lengths of the extreme satellites is less than 0.4 A. With a different
source, Fabry and Perot [32] found 0.35 A and Houstoun [33] 0.215 A.
The distance between D, and D, of sodium is 15 times 0.4 A. As far
as it has been possible to determine, the line structure for the quartz
lamp, under widely varying conditions, is such that for polariscopic
purposes, A-5461 A is a monochromatic source of great intensity and
perfect reliability. In measuring a rotation of 250°, no differences
could be detected due to changes in the emission, and probably none
for much larger rotations. The quartz lamp requires little attention
and can be operated indefinitely. Since only the lines A=5790, 5769,
5461, 4358, 4078, and 4047 A are important, the difference in wave
length is such as to permit of perfect separation of the line 5461. A by
even a relatively small dispersion, and without bringing other lines in
INTENSITY : # 4 # *
- O.3 – 0.2 -O. sea? + O. +0.2
FIGURE 11–Map of the yellow-green mercury line, x =5461.
close proximity to the edges of the slit. Hence this source permits the
elimination of practically all diffused light.
Since the adoption of x=5461A as the official source for polarimetric
measurements by the National Bureau of Standards, its universal
acceptance has been recommended by a number of investigators.
This Bureau urges its general use, especially when measuring circular
degrees in research and precision work, to the end that reliable com-
parisons may be made between the results of different investigators.
(d) CADMIUM LINES
(1) GENERAL-The necessity for a number of suitable line sources
for polariscopic work has resulted in numerous investigators giving
FIGURE 12.-Mercury vapor lamps.
A, Shows the original quartz Heraeus lamp first shown in this country at the St. Louis Exposition in 1902.
It is still in good operating condition, - -
B, Shows a group of modern mercury-vapor lamps. In the foreground is a horizontal 110-volt direct-current
Uviarc burner; on the extreme right is the same type º for operation in the vertical position; on
the extreme left is a 400-watt alternating-current lamp in glass, which is almost assatisfactory for polari-
scopic work as the more expensive quartz burners. In the middle are the 1,000-watt, water-cooled, high-
pressure quartz capillary lamp (left) and the new 600-watt alternating-current type Uviare employing
only a slight amount of mercury, all of which is vaporized in operation [34].

See legend on opposite page.

54 Circular of the National Bureau of Standards
much time to the subject. So far as possible, it is desirable that the
lines utilized be uniformly distributed throughout the visible spectrum.
Lowry [35] has suggested the following (given in angstroms):
Lithium, 6708, red; cadmium, 6438, red; sodium, 5893, yellow; mer-
cury, 5461, green; cadmium, 5086, green; cadmium, 4800, blue;
mercury, 4539, violet. 6708 and 5893 were obtained from flame
spectra, and 5461 and 4359 from the quartz-mercury lamp. The
cadmium lines 6438, 5086, and 4800 Lowry suggests be obtained
from a rotating arc. The electrodes must rotate in opposite directions
at a speed sufficiently high to prevent flickering. As electrodes, he
uses an alloy of 28 percent of cadmium and 72 percent of silver. The
melting point is 860° C. This method has been used at this Bureau
and is capable of giving excellent results. The rotating arc is, however,
rather difficult to manipulate. Some of the silver lines, namely 5469,
FIGURE 13.-Rotating arc (Cd-Ag).
5209, and 4208, may be obtained in this manner also, and with suffi-
cient intensity for polarimetric measurements.
(2) BATEs CADMIUM-GALLIUM LAMP [36].-In order to improve the
cadmium source, this Bureau has developed a vacuum type of cadmium
arc. If pure cadmium is used in a quartz lamp, the adhesion between
the cadmium and the quartz results in the destruction of the lamp
upon the solidification and cooling of the cadmium. If the cadmium
is mixed with mercury to make a soft alloy, the cracking of the lamp
is effectively prevented, but the mercury vapor then carries most of
the current, since the vapor pressure of mercury is much greater than
that of cadmium.
On the other hand, gallium although melting at about 30°C, boils
at a very high temperature, approximately 1,500° C. Its vapor
pressure is therefore negligible in comparison to that of cadmium.
Furthermore, the addition of a few drops of gallium to 10 or 15 ml of
cadmium is found to change completely the texture of the latter,
rendering it relatively soft and greatly reducing its tensile strength.
Subsequently, it was discovered that upon distilling the cadmium
from the alloy at a pressure of about 0.001 mm of mercury, the minute
quantity of gallium carried over was sufficient to change completely
the character of the cadmium and to prevent adhesion between the
cadmium and the walls of the lamp. The type of lamp usually used
is shown in figure 14.

Polarimetry, Saccharimetry, and the Sugars 55
The total volume of the lamp was approximately 10 ml. The
electrodes consisted of tungsten wires, B, entering through quartz
capillaries. These were closed with seals similar to the type described
12%
J.P
A
4-1----------|--|-
3000 *ooo Jº OO also A.
B
FIGURE 14.—A, Bates type of cadmium-gallium arc; B, gallium spectrum.
A, Cadmium-gallium alloy; B, tungsten electrode; C, lead seal; D, tungsten lead wire: E, capillary for sealing
off lamp from pump.
by Sand [37], and later by quartz-Pyrex-tungsten seals when these
became available.
In filling the lamp, cadmium containing 2 or 3 percent of gallium,
is placed in the side tube, F, and distilled under a vacuum of 0.001 mm
Hg, or better. When carefully prepared, the lamp will have an
indefinite life. One of this type has been in intermittent use for
several years and shows no sign of deterioration. The lamp may be

56 Circular of the National Bureau of Standards
started by heating with a flame to vaporize the metal. It will operate
with as little as 3 amperes and a corresponding drop of 14 volts across
the lamp, but most satisfactory results were secured with a current of
about 7 amperes and a drop of about 25 volts across the lamp. It may
be connected directly to a 110-volt direct-current power line through
a suitable resistor. Under these conditions a practically pure cadmium
spectrum of great brilliancy is obtained. There are no gallium lines
to interfere between 4200 and 6400 A, and the ones that do occur are
so faint as to be wholly negligible in polarimetric work.
(e) LITHIUM FLAME
The lithium red line (A=6708A) may be obtained in satisfactory
intensity by blowing lithium carbonate dust into an oxyhydrogen
FIGURE 15.-National Bureau of sº apparatus for obtaining the lithium
ºne-
flame. Apparatus devised for this purpose is shown in figure 15. It
consists essentially of a cylindrical glass container, at the bottom of
which is a small fan driven by a motor. Lithium carbonate, together
with a small quantity of Ottawa sand, is placed in the apparatus. The
sand, which is picked up and kept in violent motion by the fan, keeps
the carbonate from packing and acts as a sand blast, grinding the
carbonate finer and finer the longer it is operated. A slow stream of
dried air enters at the bottom and leaves at the top, laden with
lithium carbonate dust, whence it is conducted by a rubber tube to
the housing around the oxyhydrogen burner.

Polarimetry, Saccharimetry, and the Sugars 57
(f) REMARKS ON PURITY OF LIGHT
In most instances absorption filters do not accomplish sufficient
purification. For work even approaching precision, spectral purifi-
cation needs to be used even with those sources which produce line
spectra. The purity of the light used for making rotation measure-
ments has not in the past had the attention which is due it.
If one measures a normal quartz control plate, for instance, with
first one and then the other of the two D lines (A=5896 and 5890 A),
which constitute the sodium doublet, a difference of about 0.08° is
obtained. Using a good polariscope rotation measurements can be
made with a precision of about 0.003 circular degree; while even the
Smaller instruments yield a precision of about 0.01°. It is obvious,
therefore, that a monochromaticity approaching 1 angstrom unit is
required even for ordinary work, and a considerably greater degree of
purity for precision work, if the uncertainty in the rotation because
of wave-length errors is to be reduced to the same order of magnitude
as the experimental error involved in making the settings on the scale
(matching the field) of the polariscope. ~.
3. QUARTZ CONTROL PLATES
Quartz control plates are plates of crystalline quartz designed to
be used as standards of rotation to facilitate precise saccharimetric
and polarimetric measurements. They are indispensable in standard-
izing saccharimeter scales, and also in controlling saccharimetric and
polarimetric measurements in the field, by checking the over-all
accuracy of saccharimeter or polarimeter at the time the measure-
ments are being made.
Inasmuch as the highest possible precision is frequently called for
in polarimetric measurements, quartz control plates must be designed,
constructed, and standardized in a manner commensurate with neces-
Sary accuracy and dependability.
(a) REQUIREMENTS AND METHODS OF TESTING
(1) CRYSTALLINE PURITY. —First among the requirements is that
of purity; the plate must be of optically homogeneous quartz and
contain no striae, inclusions, twinning, or other flaws, which might
render the plate unreliable in service. Such flaws, even if not within
the effective aperture, i. e., flaws which occur only around the edges
covered by the mounting, are not permissible, since the changes in
temperature may cause differential expansion and set up strains in the
plate, which might make it of doubtful utility.
Plates are tested for purity by placing them between large accurately
crossed nicols in a darkened room, using an intense white-light source
and compensating for the rotation of the plate by means of a quartz
compensating-wedge system. Flaws may best be detected by focusing
the observing telescope sharply upon the plate and then rotating the
plate in its own plane. Any flaw in the plate will be seen to move
with the plate, and hence will be readily detected. With proper
technique, this can be made an exceedingly delicate test.
(2) PLANENESS AND PARALLELISM OF THE FACEs.-A second re-
quirement is that the faces of the plate shall be both plane and
parallel to a sufficient degree of precision; otherwise the plate would
58 Circular of the National Bureau of Standards
be of different thicknesses at different points throughout the free
opening, which would give a nonuniform field. At some points the
plate, being thinner or thicker, would have less or more rotation than
at other points.
Since a standard should be at least as accurate, and preferably
more so, than the instrument it is to control, or check, and since the
best modern saccharimeters are capable of approaching an accuracy
of 0.01° S, it is necessary that quartz control plates do not differ in
thickness at any point within the free aperture by more than an
amount corresponding to about 0.01° S. Since a 100° plate is 1.59 mm
thick, 0.01° S corresponds to a thickness of 0.000159 mm, or between
one-fourth and one-third wave length in air of the light usually used
in testing them.
The planeness of the faces can be tested most conveniently by
observing the interference pattern formed, by reflections from the
surface being tested, and from an optical flat. Either a mercury or a
sodium light source is satisfactory for the purpose.
The parallelism of the faces is most easily checked by observing the
lºnger rings formed by reflections from the two surfaces of the
plate. *
Both of these methods as applied to quartz control plates are
described in detail by Brodhun and Schönrock [38].
(3) Axis ERROR.—It is important that the faces of the plate be
accurately oriented at 90° to the crystallographic axis, i. e., when in
use the light shall pass through the plate in a direction parallel to the
principal or crystallographic axis of the quartz crystal. The accuracy
of the construction of the plate in this respect is checked by observing
the amount of displacement of the uniaxial interference figure when
the plate is rotated in its own plane. This scheme was used by Gum-
lich [39] and later perfected by Schönrock [40], and by Brodhun and
Schönrock [38]. The latter designed a special instrument for the
purpose, which was built by Schmidt & Haensch and also by R. Fuess.
The method is capable of a precision of a few seconds of arc, which is
more than is needed, since the tolerance permitted between the crys-
tallographic axis and the normal to the faces of the plate is 12 minutes
of arc.
(4) MoUNTING.-Another factor of great importance, and one that
in the past has not been given the attention it deserves, is that of the
mounting. The plate should be mounted loosely in a metal frame, the
axis of which forms an angle of 90° with the plate. The amount of
play between the faces of the plate and the frame should be as small
as possible, but the metal should exert no pressure upon the plate
under any conditions.
A little play around the circumference of the plate does no harm
and is desirable in checking whether the plate is free from pressure
and yet has not too much play. One of the most sensitive and re-
FIGURE 16.-A, Aacis-error apparatus for testing quartz control plates, and group of
mounted quartz plates and the optical flat used for testing the faces for planeness;
B, Bausch & Lomb type of mount; C, Hilger type of mount; (The steel ring, C,
which carries the quartz plate, G, is ground parallel and lapped down until it is just
0.00015 inch thicker than the plate. It is held in place against the flat surfaces,
A and D, by the screws, F. The shoulder, B, rests in the trough of the instrument
in the usual manner.); D, Physikalische-Technische Reichsanstalt type of mount
(dimensions in millimeters).
Polarimetry, Saccharimetry, and the Sugars
B -- *
-
2-2.3
- - - - - - - - ---------
– wººd
See legend on opposite page.



60 Circular of the National Bureau of Standards
liable tests is made by ear in a place free from disturbing noises.
If the plate is placed close to the ear and shaken sharply in a direction
parallel to the axis of the plate, no click should be heard, or at most
only a very faint one. A shake parallel to the faces should produce
a decided click, proving that the plate is not bound in position by
pressure.
(5) MEASUREMENT OF ROTATION.—Inasmuch as precision work of
the highest type is frequently called for in meeting the demands for
accuracy in standardizing quartz control plates, the mercury line,
A=5461 A, for the reasons previously outlined, is used exclusively.
Temperature coefficient.—In order to utilize this source to best
advantage, the temperature coefficient, o, of quartz for this wave
length (N=5461 A) and also the constant by-soaſpx-sus, where q is the
rotation, were determined. It was thought advisable to measure o
for this wave length, although Lang [41], Sohncke [42], and Le Chate-
lier [43] state that it has the same value for all wave lengths.
We have
q := @o (1 +ot),
where p, is the rotation at temperature t and po at zero. For any other
temperature, ti, we have
© tº bo (1+oti).
Hence
~ d; tı— 5t. º
ºb fi-d ºf
The measurements [24] were made with the most improved types
of apparatus. By computing of from the value of q at temperatures
between 4° and 50°C, the value obtained was cº-0.000144. Then
between 4° and 50°C
q :=qo (1+0.000144t). (13)
Conversion factor.—In measuring by-5502.5/dx=5491, a large number of
determinations were made, practically all of which were concor-
dant. However, in order to eliminate the personal equation and
avoid, as far as possible, errors due to the character of the sodium
source, the value of q is computed from the measurements of five
plates whose sodium values have been determined at the Physikalisch-
Technische Reichsanstalt. The mean of these values and those of
this Bureau was taken as the rotation for N=5892.5. The rotations
were measured in part with a sensitive-strip polarizing system. The
greater number, however, were made with an exceptionally good
Lippich system. The average value obtained was
*=0.85085. (14)
©x=5461
Thus any quartz rotation for the wave length 5892.5 may be ob-
tained by measuring the rotation for the wave length 5461A and mul-
tiplying it by the constant 0.85085. By this method the errors due to
the character of the sodium source of light are eliminated, and the
measurements of one observer may be readily compared with those of
another. National Bureau of Standards certificates show the rotation
in circular degrees at 20°C for wave lengths X=5461 and A=5892.5 A.
The latter is the so-called optical center of gravity of the two sodium
D1 and D3.
Polarimetry, Saccharimetry, and the Sugars - 61
Measurement.—In carrying out the rotation measurement, the
plate is placed in the air bath of the circular-scale polariscope described
on page 46, and the optical rotation carefully measured at 20° C
for spectrally purified mercury light of wave length 5461 A. In
order to eliminate accidental errors as far as practible, at least
three sets of readings are made on different days. Moreover, all
readings are compared to, and corrected by readings on a set of
standard plates which this Bureau maintains as its primary standards.
Because of the refinements in the method of checking quartz control
plates, it is believed that the sugar values certified are not in error
by more than 0.01°S, or at most 0.02°S. Repeated determinations
made several years apart seldom differ by more than this amount.
(b) NATIONAL BUREAU OF STANDARDS SPECIFICATIONS
In line with the requirements cited above, this Bureau has drawn
up the following specifications for quartz control plates:
(1) PURITY. —The plate shall be made of quartz which is optically
homogeneous, i.e., it shall be free from twinning, striae, strain, and
other optical defects.
(2) PLANENEss, PARALLELISM.–The faces of the plate shall be
both plane and parallel within the following limits: There shall be
no departure from true flatness by more than that corresponding to
one-half wave length in air of sodium light anywhere within the free
aperture of the plate, nor shall there be a radius of curvature of less
than 100 m. The plate shall not differ in thickness between any
points comprised within the free aperture by more than 0.00015 mm.
This thickness corresponds to 0.01°S.
(3) Axis ERROR.—The faces of the plate shall be accurately orien-
tated at right angles with respect to the crystallographic axis. The
axis error, i.e., the angle between the normal to the faces and the
crystallographic axis, should be as small as possible and shall not
exceed 10 or 12 minutes of arc.
(4) MoUNTING.-The plate shall be mounted loosely in a metal
frame, the axis of which forms an angle of 90° with the faces of the
plate. The amount of play between the plate and its surrounding
frame shall be as small as possible in the direction parallel to the axis
of the plate, but the metal shall exert no pressure upon the plate.
(5) DIMENSIONs.-The plates should be 15 to 17 mm in diameter
and, after mounting, should have a free aperture not less than 10 mm
in diameter. Plates having low sugar values may be, and it is recom-
mended that they be, composed of two thicker plates, one right-
rotating and one left-rotating, mounted in separate mounts of the
same type, preferably one on each end of the tube.
(c) SPECIFICATIONS OF THE INTERNATIONAL COMMISSION FOR UNIFORM
METHODS OF SUGAR ANALYSIS FOR QUARTZ CONTROL PLATES
The following resolutions were adopted by the International Com-
mission for Uniform Methods of Sugar Analysis at its Eighth Session
at Amsterdam in 1932:
1. Quality tests of saccharimeter quartz control plates.
(a) Optical purity.—At least the central 9 mm of the plate must be sufficiently
optically homogeneous. Especially plates from 90° to 102°S must not show any
323414°—42 6
62 Circular of the National Bureau of Standards
striae. During the purity test, the plate should be rotated in its own plane at
least 360° (about its own axis).
(b) Plane parallelism.—In general the wedge angle between the faces may at
most amount to not more than 20 seconds. For plates between 90° and 102°S
this limit must be 10 seconds. The radius of curvature of each of the faces shall
be not less than 50 meters.
(c) The azis error, that is, the angle between the optical axis and the normal
to the plate, may at the highest amount to 10 minutes of arc. e
2. Dimensions of the plates.—The plates must be between 15.0 and 17.0 mm in
diameter. After mounting they must have a free aperture at least 10 mm in
diameter. Plates having values below H-24°S should be composed of two thicker
plates, one plus and one minus, the combined thickness of which, however, must
be less than 1.6 mm. The edges of the plates shall be slightly beveled.
3. Identification marks.--Near the edge of the plate shall be engraved “IP”
(International Plate), the number of the plate, and the year. $º
4. Plate mountings.--It is proposed to accept the form of mounting prescribed
by the Physikalisch-Technische-Reichsanstalt wherein the plate is free from
pressure, but the clearance is a minimum. For plates below -- 24°S, the two
plates are to be mounted in separate mounts of the same type, one on each end of
the holder tube.
5. Rotation measurement.—The rotation in circular degrees shall be made at
20°C, using spectrally purified light either of wave length 5461 or 5892.5 A,
obtained, respectively, from a mercury vapor arc of suitable design, or from a
sodium light source, such as the Pirani or Osram sodium arc lamp.
6. The plates shall be tested in one or more of the four national physical labora:
tories, viz., National Bureau of Standards, Washington, D.C.; National Physical
Laboratory, Teddington, London; the Physikalisch-Technische Reichsanstalt,
Charlottenburg, Berlin; and the Laboratoire National, Paris. All details of the
tests and measurements shall be left to these four institutions.
At the Ninth Session at London in 1936, the Referee on Quartz
Control Plates made the following recommendations which were
unanimously adopted by the Commission:
1. The resolution of the Eighth Session shall be amended to read as follows:
(a) Optical purity.—The central 9 mm at least of the plate must be sufficiently
optically homogeneous. It is essential that plates from 90° to 102° S should not
show any striae. During the purity test, the plate should be rotated in its own
plane at least 360° (about its own axis). It is recommended that the four National
Physical Laboratories should investigate tests for fixing a quantitative limit to
permissible defects in homogeneity.
(b) Identification marks.—Near the edge of the plate shall be engraved “I. P.”
(International Plate), the number of the plate, the year, and the sign of the testing
National Physical Laboratory.
(c) Plate mountings.--The form of mounting to be acceptable for testing shall
be such that the plate shall be free from compression and the clearance a minimum.
For plates below 24° S, the two plates are to be mounted in separate mounts of
the same type, one on each end of the holder tube.
2. The four National Physical Laboratories, viz., National Bureau of Standards,
Washington, D. C.; National Physical Laboratory, Teddington, London; the
Physikalisch-Technische Reichsanstalt, Charlottenburg, Berlin; and the Labor-
atoire National, Paris, be requested to collaborate and determine:
(a) The rotation of the 100° S plate in circular degrees for the wave length
(optical center of gravity) produced by the Osram sodium vapor arc lamp.
(b) The rotation in circular degrees for the wave length (optical center of
gravity) produced by the Osram sodium vapor arc lamp for plates of the following
approximate values, 25, 50, 75, and 100° S. It is suggested that sets of such
º interchanged between the above laboratories for comparative tests to
be made.
(d) CERTIFICATION OF QUARTZ CONTROL PLATES
The usual procedure at this Bureau in testing quartz control plates is:
1. Examination of the mounting to see if the plate is satisfactorily
mounted.
2. Examination between crossed nicols as a test of purity.
3. Examination as to planeness and parallelism of the faces.
Polarimetry, Saccharimetry, and the Sugars 63
4. Measurement of the axis error.
If a plate satisfactorily passes these tests, its optical rotation is
measured, at 20° C, using spectrally purified light of wave length
5461 A obtained from a mercury arc.
The rotation for X=5892.5 A may be obtained by direct measure-
ment, or by multiplying the rotation for the Hg light by 0.85085.
The sugar value of the plate is then assigned, based upon either of the
two rotations given above. The sugar value is discussed more fully
below under “Saccharimeters.”
This Bureau reserves the right to reject any plate showing faults
which tend to make it unreliable.
(e) SPECIAL TESTS
Additional data upon quartz control plates submitted for test may
be had by special arrangement. Standardization for wave lengths
other than X=5461 A and X=5892.5 A will be made, provided the
Order of accuracy desired is consistent with the intensity and purity
of the source available.
4. REFERENCES
[1] Erasmus Bartholinus, Experimenta Crystalli Islandici disdiaclustici quibus
mira et insolita refractio detegitur (Amsterdam, 1670).
[2] Christian Huygens, Traité de Lumière (Leyden, 1690).
[3] l’Abbé Alexis Marie Rochon, Recueil de mémoires sur la mécanique et sur
la physique (1783).
[4] Etienne Louis Malus, Mém. Soc. d’Arcueil 2, 143, 149 (1808–1809). Mém.
Savants Étrangers 2, 303 (1810–1811). Théorie de la double refraction
(Paris, 1810).
[5] Dominique François Arago, Oeuvres complètes 10, 54. Mem. I’Institut,
Class Math. Phys. 12, 115 (1811).
[6] Jean Baptiste Biot, Mém. l’Institut, Class Math. Phys. 12, 135–280 (1811);
13, 1–371 (1812); 13, 1–18 (1813); 13, 18–38 (1814)
[7] Jean Baptiste Biot, Bul. Sciences Soc. Philomatique, 190–195 (1815).
[8] Jean Baptiste Biot, Mem. Acad. Sci. 2, 41–136. (1817.)
[9] Jean Baptiste Biot, Sur la construction des appareils destinés a observer le
pouvoir rotatoire des liquides, Ann. chim. phys. 74, 401–430 (1840).
[10] Wº; Nicol, Edinb. New Phil. J. 6, 83–94 (1828); 14, 372 (1831); 27, 332
1839).
[11] Eilhard Mitscherlich, Polarisation et Saccharimétrie, by D. Sidersky, 2d
edition (1908), page 46.
[12] Robiquet, Polarisation et Saccharimétrie, by D. Sidersky, 2d edition (1908),
page 48.
[13] K. Wentzke, Erdmann's J. prakt. Chem. 25, 65–84 (1842); 28, 111 (1843).
[14] Henri Soileil, Compt. Rend. 20, 1805 (1845); 21, 426 (1845); 24, 973 (1847);
26, 163 (1848).
[15] Joseph Johann Pohl, Wiener Bericht 22, 492 (1856).
[16] H. Laurent, J. phys. 3, 183 (1874); 8, 164 (1879).
[17] Rev. J. H. Jellet, Brit. Assn. Rep. 29, 13 (1860); Proc. Roy. Irish Acad. 7,
348 (1860); Proc. Roy. Irish Acad. 8, 279 (1863); Trans. Roy. Irish Acad.
25, 371–450 (1875); Z. ver. Rubenzuckerind. 15, 456 (1865).
[18] Alfred Cornu, Bul. Soc. Chim. Paris 14, 140 (1870).
[19]. H. Landolt, Die Polarisationsapparate Bericht tiber die wissenschaftlichen
Instrumente auf der Berliner Gewerbeausstellung in Johre, p. 357 (1879),
(Berlin, 1880).
[20] F. Lippich, Z. Instrumentenk. 2, 176 (1882); 14, 326 (1894); Weiner Ber. 91,
1059 (1885).
[21] D. B. Brace, Phil. Mag. 161–170 (1903).
[22] F. Lippich, Z. Instrumentenk. 12, 340 (1892).
[23] H. Landolt, Ber. deut. chem. Ges. 27, 2872 (1894).
[24] F. J. Bates, Bul. BS 2, 239 (1906) S34.
[25] H. Ebert, Wied. Ann. 34, 39 (1888).
64 Circular of the National Bureau of Standards
[26] H. Landolt, Optical Rotation of Organic Substances, 2d edition, p. 404.
__ _ Translated by J. H. Long (Chemical Publishing Co., Easton, Pa., 1902).
27] Pribram, Z. anal. Chem. 34, 166 (1895).
28] H. Landolt, Z. Instrumentenk. 4, 390 (1884).
[29] General Electric Vapor Lamp Co., Bulletin 900.
30] Osram, Berlin 17, Germany.
[31] Lines in the Arc Spectrum of the Elements, compiled and published by Adam
Hilger, Ltd., 98 Kings Road, London, N. W. 1, England.
[32] Ch. Fabry and A. Perot, Compt. Rend., p. 407 (1898).
[33] R. A. Houstoun, Phil Mag. 7, 456 (1904).
[34] Gºlestº Vapor Lamp Co. Bulletin 112; also Rev. Sci. Instr. 9, 325
8).
[35] T. M. Lowry, Phil. Mag. 18, 320 (1909).
[36] F. J. Bates, Sci. Pap. BS 16, 45 (1920) S371.
[37] H. J. S. Sands, Proc. Phys. Soc., London, 26, 127 (1914).
[38] E. Brodhun and O. Schönrock, Z. Instrumentenk. 22, 353 (1902).
[39] E. Gumlich, Wissensch. Abhandl. Phys.-Tech. Reichsanstalt 2, 212 (1895).
[40] O. Schönrock, Z. Instrumentenk. 22, 1 (1902).
[41]. V. Lang, Pogg. Ann. 156, 422 (1875).
[42] Sohncke, Wied. Ann. 3, 516 (1878).
[43] Le Chatelier, Compt. rend. p. 109 (1889).
IV. MEASUREMENT OF ROTATION IN SUGAR DEGREES
1. DEVELOPMENT OF THE SACCHARIMETER
(a) HISTORICAL INSTRUMENTS (FIG. 17)
In the development of the saccharimeter there are two factors that
have of necessity received most consideration. They are, first, suffi-
cient illumination of the field for average work and, second, the high-
est obtainable sensitivity consistent with meeting necessary require-
ments. Because of the rotatory dispersion, or the different rotation
for different wave lengths, precise measurement of rotation ordinarily
requires the use of a monochromatic light source. This is especially
true if the precision attainable by the utilization of the photometric
principle as realized in the halfshade is to be obtained. This condition
holds in polariscopes designed primarily for absolute measurements
of the rotation of the plane of polarization. Unfortunately a simple
monochromatic source of sufficient intensity and otherwise suitable
for all polarimetric work has never been realized. In order to obviate
this difficulty, Soleil, a Parisian optician [1], as early as 1845 invented
the first quartz-wedge compensator and applied it to the polariscope
of Robiquet, permitting the use of white light illumination and
obviating the necessity of using monochromatic light. He used a
double quartz wedge so arranged that it was in effect a quartz plate
of variable thickness, opposite in rotation to the sugar solution being
measured. Since quartz has almost the same rotatory dispersion as
sucrose, this device compensated or balanced out the rotation produced
by the sugar solution, wave length by wave length, and returned the
vibration planes of all the different wave lengths to the original vibra-
tion direction common to all before they entered the optically active
substance. Since the calibrated wedge is driven across the field until
conditions are as they were before the rotating substance was placed
in the intrument, rotatory dispersion is practically eliminated and
white light may be used.
The absence of light sources of sufficient intensity has always been
One of the most potent factors in influencing the design of sacchari-
meters. The higher limit of the sensitivity has been almost entirely
Polarimetry, Saccharimetry, and the Sugars 65
determined by this factor. Even with the average halfshade angle of
6° to 8° the polarizing and analyzing nicols are practically crossed, so
that only a mere fraction of the incident light ever reaches the eye of
the observer. If the halfshade angle is decreased in order to increase
the accuracy with which observations can be made, the intensity
of the light transmitted is rapidly reduced. Thus monochromatic
sources are inadequate in intensity when even fairly accurate settings
are to be made, unless the active substance whose rotation is to be
measured is quite transparent. Unfortunately this is not the case
with many of the optically active liquids. This is especially true
of the average raw sugar solution, and hence Soleil, as stated above,
invented the quartz-wedge compensator which permits the use of
white light with its relatively great intensity.
(b) MODERN INSTRUMENTS (FIG. 17)
The practical necessity for using white light has resulted in the
quartz compensating instrument displacing practically all other types
of saccharimeters, as is evidenced by the similarity in the perfected
instruments of Fric; Bausch & Lomb; Schmidt & Haensch; Peters;
Reichert; and others. This has been brought about despite the fact
that the compensating wedge ordinarily prevents the full use of the
adjustable halfshade angle of the Lippich polarizing system. Thus,
while the best results in the designing of polariscopes for use with a
white-light source have so far been obtained by using the Lippich
polarizing system and a quartz-wedge compensation, all makes have
had the great weakness of an unadjustable halfshade angle, and there-
fore a fixed sensitivity. Only one value of the halfshade angle can
be used, and it must necessarily be large enough to give sufficient light
to read, for example, the darkest-colored raw-sugar solutions. When
polarizing substances having a small coefficient of light absorption,
such as the better grades of sugars, are used, in which case the observer
has more light than he needs, he still has available only the low sensi-
tivity which corresponds to that value of the halfshade angle which
gives sufficient light to polarize substances with a relatively large
coefficient of absorption, such as very dark raw sugars. If then it
were possible to retain the quartz compensation and at the same time
have the halfshade angle adjustable, an advance in polariscope con-
struction would be made comparable with the invention of the wedge.
The defect due to the lack of adjustable sensitivity on a white-
light instrument has been in evidence not only in ordinary use but
especially so when the saccharimeter was used for research work.
The Ordinary quartz compensating polariscope is utilized in practi-
cally every chemical laboratory. The highest available precision of
the instrument is required in order to meet the demands of routine
use. Yet the research investigator also has been compelled to depend
upon it. The futility of taking a large number of observations on an
instrument sensitive to 0.15 percent and using the average value as
good to 0.015 percent is too well known to need discussion here.
Nevertheless, the chemist has been compelled to do this because the
majority of the research problems involving the use of the polariscope
require the measuring of rotations with a precision greater than 0.1
percent. There can be no question that the present status of polari-
metry would have been immeasurably advanced had there been a
66 Circular of the National Bureau of Standards
º =- º- -
|||||||||||||||||||||||| |||||||||||||||||||||
*
FIGURE 17–Old types of saccharimeters.
1, Ventzke's first modification of Biot's apparatus;2, Jellet's compensating saccharimeter: and 3, Laurent
quartz wedge (Soleil) saccharimeter.







Polarimetry, Saccharimetry, and the Sugars 67
FIGURE 17 (continued.)—Old types of saccharimeters.
4, Soleil-Duboscq saccharimeter (sensitive-tint biquartz plate and double quartz-wedge compensator);
5, Schmidt & Haensch type of Soleil saccharimeter; and 6, Schmidt & Haensch type saccharimeter with
Jellet-Cornu polarizer.

68
Circular of the National Bureau of Standards
º
|º
FIGURE 17 (Continued).-Modern types of saccharimeters.
1, J. & J. Fric (single wedge); 2. Schmidt & Haensch (Lippich polarizer); and 3. Jobin and Yvon.






Polarimetry, Saccharimetry, and the Sugars 69
FIGURE 17 (Continued).-Modern types of saccharimeters.
4, Bausch & Lomb (American made); 5, Bates type (J. & J. Fric) (adjustable sensitivity type).

70 Circular of the National Bureau of Standards
saccharimeter capable of being read to 0.01 percent in the hands of
chemists at an earlier date.
(c) ADJUSTABLE SENSITIVITY TYPE
In order to build a white-light polariscope with an adjustable
sensitivity, the analyzing nicol would have to rotate through a definite
angle as the halfshade angle is varied. In such an instrument it is
not sufficient that the halfshade angle be merely adjustable, but the
far more difficult requirement must be met of having it adjustable
without shift of the Zero point. This is indispensable for two reasons:
first, to permit of making polarizations with the same rapidity as on
an ordinary saccharimeter; and second, to eliminate the danger of the
observer not properly resetting the analyzing nicol whenever the half-
shade angle is changed. The designing of an instrument to meet
these requirements would be comparatively simple if the vibration
plane of the analyzing nicol bisected the halfshade angle when the
halves of the field were matched. In general, the intensities of the
light emerging from the large and small nicols of a Lippich system are
unequal. Hence when the analyzer is set for a match, its position is
different from what it would have been had the beams been of equal
intensity. The angular difference, 6, between the two positions of
the analyzer was found by Bates [2] to be
•=tºn (anº)+0.00% Cº. (15)
It is thus evident that if the vibration plane of the analyzer always
bisects the halfshade angle, the zero of the instrument will be in error
by the angle, 6, and the amount of the error depends on the halfshade
angle, o. The Zero error, 6, is much smaller and more nearly linear
with o than had been suspected. Hence in order to have a negligible
change in the zero point as the halfshade angle is varied, it should be
necessary to make only a slight modification of the ideal gear ratio in
which the analyzing nicol always turns through one-half the rotation
of the large nicol of the Lippich polarizer.
The instrument shown in figure 18 was designed at the Bureau of
Standards in 1907 [2] to fulfill the theoretical conditions mentioned
above, and is one of a number built for the Bureau and the United
States Customs Service. It was constructed by the firm of Josef &
Jan Fric, Prague, and has been brought to a high degree of perfection.
It is double quartz-wedge compensating and has a Lippich polarizing
system with the highest grade of nicol prisms. The adjustable
sensitivity is attained by a simple mechanism which acts to maintain
the analyzer in the proper position to keep the two halves of the field
at equal intensities, no matter how the halfshade angle may be varied
to suit the pleasure of the observer. In order to accomplish this, the
vibration plane of the analyzer is constantly maintained at the angle,
6, to a line bisecting the halfshade angle. A constant match of the
field results. Messrs. Fric have succeeded in doing this to such a
degree of perfection that there is no observable change in the zero
point for a halfshade angle range of 2.5° to 15°. The analyzing nicol
and the large nicol of the polarizing system are mounted in bearings
and driven by gears from a common horizontal connecting rod. The
halfshade angle is varied by turning the milled head which is geared to
Polarimetry, Saccharimetry, and the Sugars 71
the end of this rod. The angle of the halfshade angle is indicated on
an engraved dial, 3 cm in diameter, which is in constant view of the
Operator.
Another important improvement [2] has been made in the location
of the milled heads which move the quartz wedges. Heretofore
polariscope builders have mounted these heads on the ends of vertical
rods, thereby forcing the hand and arm of the observer into a cramped
and unnatural position while making the setting. It will be observed
that the milled heads are at right angles to the customary position,
thereby overcoming this objection. The wedges can be instantly
clamped rigid at any position of the scale by means of the clamps,
C and N, figure 18, B.
Both the right- and left-rotating wedges are of unusual length, and
in the present models read from +15° S to FF 105° S. Their scales
are the regulation type ordinarily used on Fric saccharimeters. With
two exceptions, the scale now used by manufacturers generally is of
metal and reads by reflected light. Owing to the shortness of the
wedge the reading is necessarily made by means of a magnifying
telescope. A black line thus usually separates the vernier and the
scale proper or may appear with usage. Owing to the fact that the
eye must bridge this line and that the edges of the rulings are not
sharp, interpolation of the vernier to hundredths is impossible, and in
many cases it is very easy to make an error of 0.1° S. The Fric scale,
which has been in use for some years, is made with the lines etched on
glass, which permits of very sharp rulings. What is of even greater
advantage, it is read by transmitted light, the black dividing line
between the vernier and the scale being thus eliminated. Not only
is this scale much easier on the eye of the observer, but it also permits
of reading accurately to 0.01° S. It is illuminated by waste light
collected by a 45° mirror, located in front of the polarizing system.
Thus it is not necessary to have any extraneous light in the room, as
all the light needed enters the instrument through the collecting lens
in the end of the tube. In investigations utilizing the saccharimeter,
where temperature corrections are to be made, it is necessary to know
accurately the temperature of the quartz wedges. Polariscope builders
do not generally make provision for this. A thermometer (10° to
40°C, in one-fifth degree) with a horizontal scale and with its bulb
between the quartz wedges has accordingly been mounted in a brass
case on top of the metal housing containing the compensator. For
all ordinary sugar testing, where the temperature of the room changes
slowly, the reading of the thermometer is practically the temperature
of the room. The observer is thus able to take the temperature of
the wedges with the same facility that he reads the scale on his instru-
ment, since the thermometer scale is in a similar position and is
illuminated by the same light source.
In general, when a tube of liquid is placed in a polariscope, there is
present a certain amount of haziness which seems to overlie the
field of view. It is due to depolarized light and interferes with the
focusing and the accurate matching of the halves of the field. By
proper diaphragming, this has been reduced to such a low minimum
that it may be said to be practically eliminated. When a tube is
placed in the instrument, the observer sees a clear, sharply defined,
circular field with no extraneous light. The observing telescope, as
well as the two reading telescopes for the scale, has screw adjustments
72 Circular of the National Bureau of Standards
which permit of accurate and rapid focusing. Still further improve-
ment has resulted from making the base of the instruments exception-
ally heavy and mounting it on rubber tips. The resulting inertia
of the instrument and friction on its supporting bench prevent acci-
dental shifting with reference to the light source.
A twofold object has been kept constantly in view in designing this
instrument: (1) to produce a saccharimeter of great flexibility for
regular commercial testing and to correct the defects of the ordinary
instrument; (2) to provide the chemist with a white-light instrument
-
F1GURE 18-4, Bates type adjustable-sensitivity saccharimeter with NBS polariscope
lamp and bichromate filter.
suitable for research work. The result has been the production of
an instrument of a greater range of adaptability than any saccha-
rimeter heretofore built. In measuring rotations with the greatest
possible accuracy, or when it is desired to make the settings with the
least possible strain on the eye, the observer has only to change the
halfshade angle until he has just sufficient light to bring the two
halves of the field to the same intensity, without undue eyestrain.
He then has for his eye an instrument so adjusted as to give the
maximum sensitivity for making the setting, no matter what the
character of the substance whose rotation is being measured.

Polarimetry, Saccharimetry, and the Sugars 73
2. BASIS OF SACCHARIMETER CALIBRATION
The specifications defining the 100° point of saccharimeters have
been changed many times since Wentzke [3] defined the normal sugar
solution in 1842.
Two markedly different saccharimeter scales are in use today, each
purporting to give the correct percentage of sucrose in a sample.
They are the French Scale and the International Sugar Scale. The
former is used largely in France and the French Colonies; the latter
is used generally throughout the rest of the world. The International
Sugar Scale is the official scale of the International Commission for
Figure 18 (Continued)–B, front view of saccharimeter shown in figure 18, A.
Uniform Methods of Sugar Analysis and was adopted at the Eighth
Session of the Commission in 1932 at Amsterdam. Obviously any
saccharimeter scale is, by definition, a basis on which the standardiza-
tion of the saccharimeter may be brought about. In any consider-
ation of the saccharimeter scale it is essential that there be kept
clearly in mind the differentiation between mere definition of the scale
and the numerical values of the constants upon which its correctness
depends. The confusion which has long existed with regard to sac-
charimeter scales may be correctly attributed to the use of incorrect
values for these constants.

74 Circular of the National Bureau of Standards
Probably no industrial commodity is so widely utilized in inter-
national trade as sucrose and its associated products. Therefore, it is
of great importance that there be but one sugar scale, that is, one
basis of standardization of saccharimeters in use throughout the
world. Such a consummation must ultimately be brought about in
view of the importance of the matter to international trade and
especially because of the necessity of reporting the results of research
workers in unmistakable values. Until this can be done, and under
present conditions, it is therefore of special importance, insofar as
the inherent characteristics of the French and the International
Sugar Scales will permit, that the two scales give results that are
in agreement within the experimental error with which saccharimeter
measurements can be made. It is fundamental that tests of a sample
of sucrose should show an identical sucrose content regardless of
the scale used.
The specific rotatory power or specific rotation [o] is, by definition
| proportional to the rotation divided by the weight per volume,
that is, -
rotation _ L-O!
—:-----— - -->
weight per volume C
|o]=constant X
or more specifically
on 100× oft'
ſoft-ºf" j (16)
where [o]} is the specific rotation at 20°C measured with the D line
of sodium, a the observed rotation, c the concentration expressed
in grams per 100 ml of solution, and l the length in decimeters.
Hence in the formulation of any saccharimeter scale based upon
the above equation, some more or less arbitrary choice of value for
either one or the other of these two quantities, o and c, must be
made before the other can be fixed.
The French chose to let the 100° point of their scale be fixed by
a definitely selected rotation, a =21°40', and to determine by experi-
ment, based upon the law stated above, what weight of sugar (which
was called the normal weight) was required to produce that rotation.
The Germans, on the other hand, following Wentzke, chose to
Select a normal weight, c, and determine by experiment what rotation,
o, corresponded thereto and to let that rotation fix the 100° point of
their scale.
It is clear that in establishing both scales actual physical measure-
ments must be made, both of the weights and of the rotations. It
therefore makes no difference in the final analysis whether the weight
be considered fundamental and the rotation consequential or whether
the rotation be considered fundamental and the weight consequential.
In the abstract both lead to the same result, namely a relation or ratio
between rotation and weight (per standard volume).
However, practical considerations, such as established usages,
choice of values which determine the openness of the scale, effect of
concentration on specific rotation, and other factors not involving
the fundamental law itself, may operate to make one particular choice
of scale preferred over another.
Polarimetry, Saccharimetry, and the Sugars 75
(a) THE FRENCH SUGAR SCALE
It is of interest to recall that the French Sugar Scale was originally
based upon the rotation of 1 mm of quartz for sodium light to fix the
100° point. This constant was determined by Broch [5] to be 21°40'
(21.667°) for sodium light. The usual procedure has been to lay off
65° on a circle and divide the 65° segment into 300 equal parts, taking
the 100th division mark as the 100° point. Instruments were con-
structed on this basis, and when it was later found that the rotation
for 1 mm of quartz was somewhat higher, the original value (21°40')
was retained in order to avoid confusion of scales. This procedure
necessitated the abandonment of the original definition of the 100°
point for the French Sugar Scale. The 100° point thus has always
been and still is fixed by the absolute rotation, 21°40'. In this sense
the French Sugar Scale has never been changed. However, the esti-
mate of the amount of sugar required to produce this rotation, namely
the value of the normal weight, has undergone many changes. Over
20 different values have been assigned to the normal weight, ranging
from 16.0 to 16.51 g. In 1875 the value of Girard and de Luynes
[6], 16.19 g, was adopted as the official weight and remained so for
more than 20 years. In 1885 [7] Sidersky called attention to the
error in the then official normal weight of 16.19 g, and was criticised
for questioning the correctness of the official normal weight [8].
Nevertheless, Sidersky had the courage of his convictions and 11
years later, in 1896, his value was made the official value. This value
(16.29 g) was based upon two considerations [8]: (1) A calculation of
the normal weight, using Tollens' value, 66.5°, for the specific rotation
of sucrose, whereby he obtained the value 16.295 g; and (2) the direct
comparison of a Schmidt & Haensch and a Laurent saccharimeter by
means of a quartz plate, which he read in both instruments. He
assumed that the Schmidt & Haensch instrument was correct, since
it was supposed to have been directly calibrated by means of pure
Sucrose, and calculated the weight which would have to be used with
the Laurent instrument to give the correct percentage of sugar. He
found for this value 16.30 g, which confirmed his calculated value,
16.295 g. It was not known at that time, as it is now, that the
Schmidt & Haensch instruments of those days were in error by about
0.2 percent, the 100° point then corresponding to an absolute rotation
of 34.68° instead of 34.620°, as at present. Had this error been known
at that time, Sidersky’s experiment would have yielded a result of 0.2
percent lower, or 16.27 g. Also, all subsequent determinations of the
French normal weight have yielded results slightly lower than 16.29 g.
Following the action of the II* Congres International de Chimie
Appliquée (Paris, 1896) in adopting 16.29 g as the official normal
weight for the French Sugar Scale, a commission was appointed for
the revision of the saccharimetric normal weight. This commission
decided that further experimental work was required in order to estab-
lish the normal weight on a firm foundation. This work was under-
taken by Mascart and Benard [9] at the Collége de France and also by
Pellet [10] at the Sorbonne.
As a result of these experiments the correctness of the value 16.29 g
was considered to be amply confirmed. However, it has been recently
pointed out [11] that had the values actually found by these observers
been used instead of the official value which it was considered they
76 Circular of the National Bureau of Standards
had corroborated, the French Sugar Scale would from that time on
have been in agreement with the International Sugar Scale which was
adopted by the International Commission for Uniform Methods of
Sugar Analysis at Amsterdam in 1932. Mascart and Benard [9]
gave 66.54° as the specific rotation of sucrose, and 16.284 g weighed
in vacuo as the normal weight. Through an error in converting this
weight in vacuo to weight in air with brass weights, they arrived at
the value 16.29, confirming Sidersky's calculation. If this error is
eliminated, Mascart and Benard's value becomes 16.27 g.
Also Pellet [10] gave [o]}=66.536, and 16.285 g in vacuo for
the normal weight. The latter corresponds to 16.27 g weighed in air
with brass weights.
In 1933, 38 years after his original calculation, Sidersky [8] accepted
the specific rotation of 66.54° given by Schönrock [12] as the best
average value and again calculated the normal weight and found the
value to be 16.282 g. This he said differed by only a negligible
amount from 16.29 g. Sidersky appears to have overlooked the
fact that the specific rotation calculated from Schönrock's formula,
which he accepted, is that based upon weights in vacuo, and hence
that the normal weight which he obtained is the normal weight in
vacuo. Corrected to weighings in air with brass weights, his figure
becomes 16.272 g. If 21.667° be used, instead of 21.67° which
Sidersky used, this figure is still further reduced to 16.270 g.
It has also been shown [11] by calculation from the best available
constants that a French normal weight of 16.269 g would be necessary
to bring the French Sugar Scale and the scale of the International
Commission for Uniform Methods of Sugar Analysis into equivalence.
This normal weight exactly (considering that the tolerance of experi-
mental error is set at 0.002) equals that calculated by Sidersky,
namely 16.270 g, after due attention is paid to the obviously necessary
correction for buoyancy of the air and the 100° French Sugar Scale
point rotation taken as 21.667°, instead of 21.67°, and also is the
same as that actually indicated by the data of both Mascart and Be-
nard and of Pellet.
Since the 100° point of the French Sugar Scale is fixed by definition
as a rotation of 21°40' or 21.667°, it is advisable to use the latter
figure to replace the less accurate value of 21.67° now used. Parallel-
ing the definition of the International Sugar Scale, the following
statement holds for the corrected French Sugar Scale:
(1) Normal quartz plate=100° French Sugar Scale=21.667
+0.002° (X=5892.5 A) at 20° C.
(2) The graduation of the saccharimeter shall be made at 20° C.
16.269 +0.002 g of sucrose dissolved in water, and the volume made
up to 100 ml, all weighings to be made in air with brass weights, the
completion of the volume and the polarization to be made at 20°C,
on an instrument graduated at 20°C, gives a reading of 100° French
Sugar Scale.
Quoting from Bates and Phelps [11]:
From a consideration of the foregoing it is apparent that many of the difficulties
and uncertainties which have been attributed to the French Sugar Scale never
had an actual existence. They have arisen through an error in adopting a normal
weight which the experimental evidence did not fully justify. It should be a
simple procedure to eliminate them. It is therefore suggested that the value
16.269 + 0.002 g weighed in air with brass weights be adopted as the official
Polarimetry, Saccharimetry, and the Sugars 77
normal weight for the French Sugar Scale. When this is done the present official
normal weight of 16.29 g will have been discarded. Should this be done, not
only will the International Sugar Scale and the French Sugar Scale be brought
into exact agreement but there will result a long-overdue recognition of the
accuracy of the experimental work of those French investigators whose work
was interpreted as providing a value of 16.29 g for the normal weight. It is a
fortuitous circumstance that brings the two scales into complete correspondence,
and it is worthy of note that these investigators, with the limited facilities avail-
able at the early date at which the work was carried out, obtained values for the
specific rotation and the normal weight of sucrose identical with those obtained
by the use of modern instruments and methods. The adoption of the normal
weight, 16.269 g, as the official normal weight for the French Sugar Scale would
be an important development of great benefit to the sugar industry of the world.
This has now become an accomplished fact. By an official de-
cision of March 26, 1938, the French Minister of the Budget ratified
the change from 16.29 to 16.269 +0.002 g for the official French
normal weight, to be eflective September 1, 1938 [13].
(b) THE GERMAN, OR VENTZKE, SCALE
Wentzke [3], in 1842–43, proposed a method for establishing the
sugar scale which would make the use of a chemical balance unneces-
sary. The 100° point of his scale was established by the rotation of
a sucrose solution having a specific gravity of 1.100 at 17.5°C referred
to water at 17.5° C. However, it was soon found that the specific-
gravity method was unsatisfactory in use. Accordingly the weight
of sucrose in 100 ml of Wentzke's solution, namely 26.048 g, was
taken as the normal weight and the specific-gravity method was
abandoned. Many of the old instruments were made for use with
26.048 g in 100 ml.
When the Mohr sugar flask came into general use in 1855, polari-
scope builders began determining the 100° point by the use of this
flask and the same normal weight, 26.048 g, as before, which was of
course an entirely different basis, since 100 Mohr co equals 100.234 ml.
Many saccharimeters in use today were constructed on this basis,
which may be more fully stated as follows:
The 100° point (Wentzke) is determined by the rotation in a 200-mm
tube of a solution containing 26.048 g of sucrose, weighed in air with
brass weights, in 100 Mohr ce at 17.5°C, the temperature of the
quartz wedges, as well as the polarization temperature, being 17.5°C.
From 1855 to 1900 practically all saccharimeters except those using
the French Sugar Scale had their 100° points determined on the
basis given by this last definition of the Wentzke Scale. -
(c) THE INTERNATIONAL SUGAR SCALE
The Wentzke Scale, although in general use for many years, has
never been fully understood by polariscopists generally. This has
led to much confusion and to the use of 100-ml flasks on instruments
standardized for use with the Mohr flask. In addition, 17.5° C is
well below the temperature of the average laboratory. Because of
these and other considerations, the International Commission for
Uniform Methods of Sugar Analysis at the Paris meeting in 1900
recommended the use of a new definition of the 100° point [14],
based upon “true ce” and a standard temperature of 20° C. The
change to 20° C necessitated a change in the normal weight in order
to keep the physical dimensions of the new scale comparable with those
323414°–42——7
78 Circular of the National Bureau of Standards
of the Wentzke Scale. Correcting for the change in the specific rota-
tion (–0.000184), the expansion of a glass tube (+0.000008), quartz
wedge (–0.000130), and metal scale (–0.000018), the new weight
was calculated to be 26.01 + g. It was thought advisable to ignore
the small fraction and use the round number 26.00 as the normal
weight, and the Commission officially so decided [14]. Owing to the
absence of a more suitable term, and in order to divorce it as completely
as possible from confusion with the Wentzke Scale, the new scale was
referred to as the International Sugar Scale. The International Sugar
Scale then was defined at the Paris meeting as follows: “The gradua-
tion of the saccharimeter shall be made at 20°C, 26.00 g of sucrose
dissolved in water and the volume made up to 100 metric ce and
polarized in a 200-mm tube. All weighings are to be made in air with
brass weights, the completion of the volume and the polarization are
to be made at 20° C. This will determine the 100° point.”
The advantages of the new scale were at once appreciated. It has
been adopted by the National Bureau of Standards, the United States
Treasury Department, the Physikalisch-Technische Reichsanstalt, the
Institut für Zucker-Industrie and also by the makers of saccharimeters.
(1) HERZFELD-SCHöNRock VERSION.—Following this meeting of
the Commission, Herzfeld [15] and Schönrock [16] (1901–04), on the
basis of the above definition of the International Sugar Scale, stan-
dardized a number of quartz control plates on the saccharimeter and
then measured their optical rotation for sodium light. They found,
as the average of 10 plates, that a quartz plate which read 100° on
the quartz-wedge saccharimeter with white light, filtered through
bichromate, read 34.657° on a circular-scale polariscope for sodium
light. This value, 34.657, became known as the Herzfeld-Schönrock
conversion factor. By the use of this factor, optical rotations of
quartz plates determined with sodium light could be converted into
saccharimeter degrees and the standardization of saccharimeters
effected without resorting to the use of a pure sucrose solution, which
is always difficult to prepare. This version of the International Sugar
Scale—namely the one which for all practical purposes had its 100°
point set by the rotation in the saccharimeter of a quartz control
plate of such thickness that its rotation for sodium light was 34.657–
has frequently been referred to as the Herzfeld-Schönrock scale. This
scale was the practical formulation of the International Sugar Scale
as defined at the meeting in 1900 of the Commission and remained in
practically world-wide use for many years.
(2) BATES-JACKSON VERSION.—At the meeting of the International
Commission for Uniform Methods of Sugar Analysis in 1912 in New
York, Bates reported [17] that work at the National Bureau of
Standards indicated that the Herzfeld-Schönrock scale was not quite
correct. A committee was appointed to investigate the question and
report on it at the next meeting. The war intervened and the sched-
uled meeting was not held.
In 1916 Bates and Jackson [18] published their work on the rede-
termination of the 100° point of the saccharimeter, wherein it was
shown that a normal solution of pure sucrose read only 99.895° on the
Herzfeld-Schönrock scale, and consequently the 100° point should be
where the 99.895° point then was, and that the corresponding quartz
control plate read 34.620 for sodium light and 40.690 for mercury
green. Because there seemed little likelihood, due to international
Polarimetry, Saccharimetry, and the Sugars 79
conditions, that the Commission would again meet for some time to
come, the values found by Bates and Jackson were officially adopted
by the National Bureau of Standards and the United States Treasury
Department without waiting for the reconvening of the Commission,
and were used in all of their subsequent work. Their lead was fol-
lowed by makers of saccharimeters and by others generally throughout
the sugar world. This version of the International Sugar Scale became
widely known as the Bates-Jackson scale. The publication of this
work stimulated great activity in the field, and although its validity
was at first questioned in certain quarters, yet later, as more and more
data were accumulated by world-wide investigators, it was found to be
correct. In fact, when the Commission finally met in 1932 in Am-
sterdam [19], after a lapse of 20 years, it was found that the average
of all the values determined by investigators of international promi-
nence working in various parts of the world was exactly that found by
Bates and Jackson and reported in 1916.
(3) AMSTERDAM VERSION (1932) [19].—At this meeting in 1932
the Commission adopted, under subject 1, the following resolutions:
(a) It is recommended that this Commission adopt a standard scale for the
saccharimeter and that this scale be known as the “International Sugar Scale.”
Rotations expressed in this scale shall be designated as degrees sugar (° S).
(b) It is recommended that the polarization of the normal solution (26.000 g of
pure sucrose dissolved in 100 ml, and polarized at 20° C in a 200-mm tube, using
white light and the dichromate filter as defined by the Commission) be accepted
as the basis of calibration 6f the 100° point on the International Sugar Scale.
(c) It is recommended that the reading of the normal sugar solution on the
Herzfeld-Schönrock Scale be accepted as 99.90° S.
(d) It is recommended that the following rotations shall hold for the normal
quartz plate of the International Sugar Scale:
Normal Quartz Plate = 100° S=40.690°,+0.002 (X=5461 A) at 20° C. }(17)
1° (X=5461 A) = 2.4576° S. -
Normal Quartz Plate = 100° S = 34.620°-- 0.002 (X=5892.5 A) at 20° C. }(18)
1° (X=5892.5 A) = 2.8885° S.
(e) It is recommended that the Commission suggest that new saccharimeters
be graduated in accordance with the International Sugar Scale and be inscribed
by the manufacturers with the phrase, “International Sugar Scale.” In the case
of existing instruments graduated on the Herzfeld-Schönrock scale, it shall be
permitted either to change the saccharimeter scale or to use a weight of 26.026 g
in 100 ml.
(f) It is recommended that the method of purification of sucrose for use in
fixing the 100° point on the saccharimeter scale, which was adopted at the Paris
session of the Commission (in 1900), be subjected to further study.
(g) It is proposed that the recommendations (a) to (e) shall come into effect
on September 1st, 1933.
At first reading it might appear that (b), (c), and (d) are three
different definitions of the 100° point which might or might not be
concordant. A little consideration, however, will show that (b) is a
general restatement of the fundamental basis of the saccharimeter
scale, while (c) is a recognition of the essential correctness of a par-
ticular numerical value which had been arrived at through the appli-
cation of the general definitions of (b) to the then existing sugar scale.
(c) thus transfers the general definition (b) to the actual physical
instruments used for sugar testing and is the concrete physical ex-
pression, as determined by experiment, of the fundamental definition
given in (b).
80 Circular of the National Bureau of Standards
In (d) there is set up an equivalent secondary or working standard,
based upon the numerical value in (c), whereby saccharimeter scales
may be checked or standardized without recourse to the difficult
procedure of preparing and using a normal solution of pure sucrose.
In fact, having once determined the correct quartz control-plate
equivalent (conversion factor), the original definition of the sac-
charimetric scale could be lost or discarded without affecting the
graduation or standardization of saccharimeters. The 100° point
could at any time be set or checked by the simple expedient of using
a quartz control plate whose absolute rotation is 34.620° for sodium
light or 40.690° for mercury light of wave length 5461 A. Since the
values of such plates are not subject to change, they are far more
convenient for the calibration and checking of saccharimeter scales
than the normal solution of sucrose.
It is thus seen that (d) is the practical expression of (b) and (c) in
terms of the absolute rotation of a quartz control plate and supplies
the means whereby saccharimeter scales may be readily duplicated
or checked.
(4) CoRRECTION OF SACCHARIMETERs To THE INTERNATIONAL SUGAR
SCALE.-In Resolution 1 (e) adopted by the International Commission
for Uniform Methods of Sugar Analysis in 1932 in regard to the method
of correcting saccharimeters to the new scale [19], two alternatives are
provided: (1) “. . . it shall be permitted either to change the sac-
charimeter scale or” (2) “to use a weight of 26.026 g in 100 ml.” The
second alternative, namely changing the normal weight by a slight
amount, is objectionable from the standpoint of introducing additional
complications and is therefore to be discouraged.
The first alternative is much to be preferred, namely to change the
Saccharimeter scale. This does not mean that the existing scale must
be removed and regraduated or replaced. It is sufficient to change
the scale by the simple procedure of recalibrating it in terms of the
desired scale by the use of standardized (International Sugar Scale)
quartz control plates and applying the small scale corrections so
obtained to all polarizations made in the subsequent use of the instru-
ment. It is worthy of note that scale corrections resulting from
inaccuracies in the wedges and other optical parts, including residual
inaccuracies in the scale itself, may in many instances be nearly as
large as the corrections referred to above and for accurate work must
be taken into account either by the use of a calibration table or chart
or by the use of a standard quartz control plate. No additional
inconvenience is involved, therefore, if the corrections due to change
of scale are included with those due to residual inaccuracies in the
construction of the instrument.
3. ADDITIONAL CONSTANTS OF THE QUARTZ-WEDGE
SACCHARIMETER
(a) ROTATION RATIOS FOR QUARTZ AND SUCROSE SOLUTIONS
The ratios of the rotations in circular degrees of quartz and of sucrose
solutions for two wave lengths have been determined as follows: [18]
20 -
For quartz ºs-0,85085 (19)
q,20, = 5461 A
Polarimetry, Saccharimetry, and the Sugars 81
20
and for sugar *=0.84922 (20)
2
q, "A-sº A.
(b) ABSOLUTE ROTATION OF NORMAL SUCROSE SOLUTION
The rotation of the normal sugar solution for X=5461 A was found
by direct measurement.
Normal sugar solution= 100° sugar=40.763°. (21)
Since the rotation ratio for the normal solution for X=5892.5 A and
X=5461 A is shown by eq 20 to be 0.84922, the rotation of the normal
solution for X=5892.5 A is -
Normal sugar solution = 100° sugar=34.617°. (22)
(c) ROTATORY DISPERSION CURVES OF QUARTZ AND NORMAL SUCROSE SOLUTION
The difference between the rotations of the normal quartz plate and
the normal solution for X=5892.5 A is shown to be 0.003° and for
X=5461 A 0.073°. The values indicate that the rotatory dispersion
curves of plate and solution cross at about A=5850 A. The reading
of the normal solution on the true saccharimeter scale with the source
X=5892.5 A has been calculated to be 99.99°S.
(d) ROTATION DIFFERENCE, IN SUGAR DEGREES, FOR NORMAL SUCROSE SOLUTION
BETWEEN A=5461 A AND X=5892.5 A
The difference in rotation in sugar degrees, for the normal solution
on the saccharimeter, for the sources X=5461 A and X=5892.5 A,
was calculated from the absolute rotations, with the following result:
Saccharimeter reading (X=5461 A)—saccharimeter reading
(X=5892.5 A)=0.192S. (23)
An independent experimental determination was made of this
difference and the value 0.185° obtained.
(e) THICKNESS OF THE NORMAL QUARTZ PLATE
Inasmuch as the value of the conversion factor, i.e., the rotation of
the normal quartz plate, is found to be 34.620° for X=5892.5 A and
40.690° for X=5461 A, the old value of 1.5958 mm for the thickness
of the normal plate is no longer applicable. Gumlich [20], as the
result of a painstaking investigation, found the rotation of 1 mm of
Quartz for X=5892.5 A (the light traveling parallel to the optic axis)
to be 21.7182°--0.0005 at 20° C. Recently Lowry [21, 22) has made
a number of measurements on the rotation of quartz and finds at
20°C 21.7283° per mm for (X=5892.5 A) and 25.5371° per mm for
X=5461 A. The values of the thickness of the normal plate calcu-
lated from the above data are given in table 4. The argeement
between the second and third values in column 4 is very satisfactory in
view of the fact that two independent values of the rotation per
millimeter are used. The agreement between Gumlich's and Lowry's
values for sodium light is not satisfactory.
82 Circular of the National Bureau ºf Standards
TABLE 4.—Thickness of the normal quartz plate
Wave Rotation of 1 mm of risis
- Thickness
length of ; 4.x if gº Quartz at 20° C.;
light Rotation of normal platº light parallel to op- Of ºal
SOUIrCG tic axis plate
1 2 3 4 |
A. 777 Jºl
5S92. 5 34.620° (Pates and Jackson) 21.7182° (Gunnlich) 1, 594()
5892. 5 34.620° (Bates and Jackson) 21. 7283° (Lowry) 1. 5934
5461. 40.690° (Bates and Jackson) 25. 53.71° (Lowry) 1, 5934
(f) SPECIFIC ROTATION OF SUCROSE
Of all the polarimetric constants relating to the sugars, none has
received the thorough study by numerous investigators that has been
given to the specific rotation of sucrose and its variations with con-
centration. The formulas of Tollens [23] and of Nasini and Villa-
vecchia [24] giving the values at different concentrations have been
generally accepted as the most accurate. Landolt (25) combined the
two, giving [o]...g.; A =66.435–H 0.00870c–0.000235c”(c=0 to 65),
where c is the number of grams per 100 ml of solution. This equation
gives a specific rotation of 66.502° for 26.016 g per 100 ml (vacuo).
From a critical survey of the work involving the specific rotation
of sucrose, performed by prominent investigators in various parts of
the world, it appears that the most likely value for this constant is
very close to 66.53° for 26 g of sucrose in 100 ml of solution and
for sodium light (weighings in air with brass wits.).
In the light of this work Landolt's formula has been adjusted to
give 66.53° at 20°C for 26.016 g per 100 ml (weighed in vacuo). The
adjusted equation follows:
[o]... a. a = 66.462°-1-0.00870c 0.000235c” (24)
This equation gives |o]=66.53° for 26.016 g of sucrose in 100 ml of
solution and 66.54° for 16.280 g in 100 ml.
Bates and Jackson [18] in their investigation on the constants of the
quartz-wedge saccharimeter made a determination of the specific
rotation for two wave lengths. They found that the rotation of the
normal solution for X=5892.5 A is 34.617°, and for X=5461 A is
40.763°. Since this solution contains 26.016 g of sugar (weighed in
vacuo) in 100 ml at 20°C,
100×34,617
|aliºs a =#=66.520° (25)
and
º 100 × 40.763 —, , , Tº
|alºg, a ="º-78342°. (26)
(g) NORMAL WEIGHT OF DEXTROSE
Dextrose may be determined upon the saccharimeter, the readings
being directly in percent dextrose, provided the correct normal weight
for this sugar is used. This saccharimetric constant, namely the
weight of dextrose, which when dissolved in 100 ml of solution and
Polarimetry, Saccharimetry, and the Sugars 83
read in a 200-mm polariscope tube with white light and bichromate
filter, gives a reading of 100° S on the International Sugar Scale
(conversion factor, 34.620), has been carefully determined by Jackson
[26] at the National Bureau of Standards and found to be 32.231 g
weighed in air with brass weights, and 32.2515 g weighed in vacuo.
For concentrations less than normal, the rotations deviate consider-
ably from proportionality. It is therefore necessary to correct for
this deviation. Table 74, page 562, gives the corrections to be applied
to the scale readings in order to obtain the true percentage of dextrose.
These corrections are based upon the use of a standard 200-mm tube;
hence, if any other tube-length is used, this fact must be taken into
account. For example, if a 400-mm tube is used, giving twice as large
a scale reading as the standard 200-mm tube for the same concentra-
tion of dextrose, the observed scale reading obviously must be halved
before entering the table to obtain the proper correction.
(h) ROTATION OF NORMAL SOLUTION AND THE SPECIFIC ROTATION OF DEXTROSE
Jackson found for the rotation of the normal dextrose solution the
value 40.897° for the wave length X=5461 A. The corresponding
value for sucrose is 40.763° and the rotation of the normal quartz
plate is 40.690°. There is thus a considerably greater difference be-
tween the rotatory dispersion curves of dextrose and quartz than be-
tween sucrose and quartz. This difference between dextrose and
quartz is not as thoroughly eliminated by the bichromate filter as is
the corresponding difference between sucrose and quartz (see fig. 19).
A slight difference in color between the two halves of the field results
when the quartz-wedge saccharimeter is set for a photometric match.
This necessarily causes a lower degree of reproducibility for dextrose
than for sucrose solutions. The difficulty is partially overcome by an
increased number of settings or by increased experience on the part
of the observer.
The specific rotation of dextrose solutions varies with the concen-
tration according to the formula
[o]; A = 62.032–H 0.04257c,
where c is grams of anhydrous dextrose weighed in vacuo and contained
in 100 ml of solution, or the formula
[o]; A =62.032–H 0.04220p–H 0.0001897p”,
where p is percentage dextrose by weight in vacuo.
(i) SPECIFIC ROTATIONS OF OTHER SUGARS
See tables 73, 75, and 76, beginning on page 562.
(j) CONVERSION AND SCALE COMPARISON FACTORS
Table 5(a) gives equivalents of various types of sugar scales in
circular degrees.
Table 5(b) gives figures based upon the magnitude of the circular-
degree rotations given in table 5(a) and therefore are useful only in
giving an idea of the relative physical size or length of the different
scales. These values cannot be used for converting from one scale
into another, as the normal weight must also be taken into account.
84 Circular of the National Bureau of Standards
However, they would hold as a conversion factor if, for example, 26 g
were used as the normal weight on an instrument graduated on the
French Sugar Scale.
TABLE 5.—Saccharimeter scale
[Normal weight 26.000 g, International Sugar Scale; 16.269 g, French Sugar
Scale; 10.000 g, Wild Sugar Scale]
Scale Factor Equivalent
(a) CONVERSION FACTORS
1° International Sugar Scale- - - - - - - - - - - - - - - - . . . . . . . . . . . . 0.34620° Angular rotation D.
1° Angular rotation D. ------ - - - - - - - - - - -- - - - - - - - - - - - - - - - - - 2.8885° International Sugar Scale.
1° French Sugar Scale. -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 0.21667° Angular rotation D.
1° Angular rotation D- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4,6153° | French Sugar Scale.
1° Wild Sugar Scale - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 0. 13284° | Angular rotation D.
1° Angular rotation D. - - - - - - - - - - - - - - - - - - - - - - - --------- - 7.52814° | Wild Sugar Scale.
(b) COMPARISON FACTORS
1° French Sugar Scale ---------- . . . . . . . . . . . . . . . . . . . . . . . . . 0.62585° International Sugar Scale.
1° International Sugar Scale- - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - 1. 59782° French Sugar Scale.
1° Wild Sugar Scale--------...------------. - - - - - - - - - - . . . . . 0.38371° International Sugar Scale.
1 International Sugar Scale --------------- . . . . . . . . . . . . . . 2. 60614° | Wild Sugar Scale.
1° Wild Sugar Scale- - - - - - - - - - - - - - - - . . . . . -- . . . . . . . -----. 0.61310° | French Sugar Scale.
1° French Sugar Scale. --- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1.63106° | Wild Sugar Scale.
4. LIGHT SOURCES FOR SACCHARIMETERS
(a) GENERAL
It has been unfortunate in the development of saccharimetry that
more consideration was not given from the beginning to the question
of suitable light sources and particularly to the influence of the source
on the saccharimeter reading. It has been a more or less common
practice among the users of saccharimeters to employ whatever source
happened to be most convenient without adequate consideration of
its effect upon the reading.
The light originally used in setting the 100° point of the sacchari-
meter was light from the Auer or Welsbach incandescent gas mantle,
filtered through a proper bichromate filter. This has been largely
displaced today by the electric incandescent lamp in various forms,
which is far more satisfactory from the standpoint of constancy and
ease of operation. A proper filter should be used, however, in every
Cà.S6.
(b) BICHROMATE FILTER
While the saccharimeter is based upon the use of a quartz com-
pensating system originally devised by Soleil, whose function is to
balance out the rotation of the substance being measured by the
insertion of a layer of quartz whose rotation is exactly the same in
amount but opposite in direction to that of the substance being
measured, yet the compensation is never absolutely complete. For
white light containing all wave lengths of the visible spectrum, the
compensation can be exact for only one substance, namely quartz.
Owing to the fact that the rotation dispersion curves of Optically
active substances are not identical, the quartz-wedge system does not
completely return the polarization planes of all waves to their original
Polarimetry, Saccharimetry, and the Sugars 85
positions from which they had been rotated by the substance being
tested. In the case of a solution of sugar the rotatory dispersion is
nearly the same as that of quartz, but the divergence is sufficient in
the green and blue end of the spectrum (see fig. 19 curves S, Q, and
S— Q) to cause the halves of the field to appear of different tints. The
field must appear uniform in color if the readings by different observers
are to agree. Obviously the same instrument will also give different
readings with different sources inasmuch as the luminosity curves of
the sources are different. In testing sugar, the field may be made
almost uniform in color for all incandescent sources of ordinary
intensity by placing a cell of potassium bichromate solution between
the polarizing system and the lamp. The function of this filter is to
eliminate by absorption most of the shorter waves from the visible
spectrum. Some saccharimeters are provided with a cell, fitted in
the metal tube which houses the polarizing system, for containing the
absorbing solution. Owing to their small diameter and also to the
possibility of leakage inside the instrument, this Bureau has not
found these cells satisfactory. Better results have been obtained by
using a cell with a diameter of 40 or 50 mm placed between the
Saccharimeter and the light source. Any thickness may be used, but
the optical path in the bichromate solution should, however, always
be equivalent to a layer of liquid 15 mm thick for a 6-percent solution.
If the cell is not 15 mm in thickness, the concentration of the solution
must be changed accordingly. A simple rule, satisfactory for sucrose,
is always to have the product of the thickness in millimeters and the
percentage concentration equal to 90. In some instances where the
rotation dispersion differs to a greater extent from that of quartz, as
in the case of dextrose and some other sugars, it is found advisable
to restrict the short-wave end of the spectrum still more by using
2 cm of a 9-percent solution, or the equivalent.
Figure 19 shows the importance of the use of a bichromate filter for
white-light saccharimetry. The curve marked 6 gives the transmission
(uncorrected for reflection) of a layer 1.5 cm thick of a 6-percent
potassium bichromate solution, while that marked 9 gives the trans-
mission of a 2.0-cm layer of a 9-percent solution. It will be
noted that wave lengths to the left of these curves are absorbed while
those to the right are transmitted. The curve marked Q shows the
rotation, plotted against wave length, of the normal quartz control
plate, while the curve marked S is the rotation of the normal sucrose
solution. Because of the impossibility of plotting these two curves
on a sufficiently large scale, they appear to be identical over most of
their length, diverging slightly only in the blue, yet there are small
systematic differences between them which are of great importance
in saccharimetry. These differences, S-Q, have been plotted as a
function of the wave length on a magnified scale, shown on the right,
100 times as great as that upon which S and Q separately are plotted.
The dotted curve gives approximately the corresponding differences
#. between the normal dextrose solution and the normal quartz
plate.
The curve S-Q shows the residual amount of rotation at each
wave length produced by sucrose which is not balanced out by the
quartz-wedge compensating system. It will be seen that there is
considerable unbalance in the blue and even in the green but that
light of these wave lengths is effectively eliminated by the bichromate
86 Circular of the National Bureau of Standards
solution, leaving only that part of the spectrum in which S-Q is
negligible in the case of sucrose. In the case of dextrose this is true
to a lesser extent.
Owing to the fact that the bichromate absorption cell is indispen-
sable when a white-light source is used and that a suitable and con-
Venient form has not been available, the type shown in figure 20 has
been designed at this Bureau especially for saccharimetric use. The
cell is entirely of glass with an inner separation of the plate-glass walls
of 15 mm. It is mounted in a metal frame carried on the stand, F.
The height is adjustable with ample range to fit any saccharimeter.
To utilize the filter it is only necessary to fill the cell with a 6-percent

9C) 21-T :
à 8O 24217
5
o 7O
Crº
§eo | SS 50
O NYS
Or N Q \s
C 5O N S 4O
^
2 ^ -
§ 40 N 3O
^
QQ | T->
à 30 N \ H=l— 20 7
: \ TI- || (ſ)
Or \
H 20 vº IO
º: N- N. |
Šio | so O
Or. / SST-
ul Nº.
0– / Ho
440 460 480 500 52O 54O 560 58O 6OO 62O 640 660 68O 700
WAVE LENGTH
FIGURE 19.-Spectral transmission curves for bichromate filter.
Comparison of spectral-rotation curves for the normal quartz plate and normal sucrose solution, and the
Cutoff of these latter curves by the bichromate filter.
solution of potassium bichromate and place it between the light source
and the polarizer, preferably as close to the latter as possible. Re-
cently a new mount has been designed for this cell and built as an in-
tegral part of the lamp housing (fig. 21), thus doing away with the
need for the separate stand shown in figure 20. -
Colored glasses whose absorption very closely approximates that
of the 1.5-cm layer of a 6-percent bichromate solution are now avail-
able commercially.” These are far more convenient to use and serve
admirably to accomplish the same primary function as the bichromate
solution, namely the removal of the blue end of the spectrum. How-
eyer, they are open to the possible objection that they are not so
efficient in removing heat rays from the lamp as is the water solution.
When they are used, it may be desirable in some instances for precision
* Bausch & Lomb Optical Co., Rochester, N.Y.; Corning Glass Works, Corning, N. Y.
Polarimetry, Saccharimetry, and the Sugars 87
work to use a plain water cell or a heat-absorbing glass between the
lamp and saccharimeter to prevent heat rays from being absorbed by
the solution under test. Should colored glasses be used, care should be
taken to make sure they actually have the same spectral transmission
as the specified bichromate solution. Instances have been observed
where saccharimeters sent to this Bureau for test were equipped with
º NYN * B
ſ S/SN
ſ / Miłł.
rº A M | NC
ſ %
15M.M.
> 2M.M.
O
tſ)
f^) A
-—’ſº
ſ R
º ſ SAN
|A
S
Y.
FIGURE 20.-Bichromate filter and stand for saccharimeters (NBS design).
21, body of glass cell; B, B', metal cell holder; C, washer; D, glass end plates of cell; E, ground-glass stopper;
F, stand and locking device; G, threaded cap; S, Solid rod.
colored glasses, of foreign make, which did not even approximate the
bichromate solution in their spectral characteristics.
(c) INFLUENCE ON READING
In 1904 Schönrock [16] made an investigation of the effect of differ-
ent light sources on the saccharimeter reading. His results are
summarized in table 6.


88 Circular of the National Bureau of Standards
TABLE 6.-Effect of light sources on the 100° S point
Optical Sacchar-
Light Source Purification Center Of imeter
gravity reading
A S0
White light--, - - - - - - - - - - - - - - - - - - - - - - - - - - Bichromate Solution - - - - - - - - - - - - - - - - About 6000 100.00
Sodium-------------------------------. Dispersion by prism - - - - - - - - - - - - - - - - 5893 100. 03
Poº--------------------------------- Bichromate Solution- - - - - - - - - - - - - - - 5893 100. 03
White light.--------- - - - - - - - - - - - - - - - - - - - None------------------------ - - - - - - About 5510 100. 12
“Yollow-green” mercury line - - - - - - - - - - - Dispersion by prism - - - - - - - - - - - - - - - - 5461 100, 15
Electric -----. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Color-glass 436/11 - - - - - - - - - - - - - - - - - - - - About 5200 100. 224
The data in table 6 were obtained with uncolored sugar solutions.
It will be observed that with a white-light source the presence of the
bichromate absorbing solution makes a difference of 0.12° in the
Saccharimeter reading. It thus becomes important that the instru-
ment be used under the same conditions as prevailed at the time it was
standardized. If, as is usually the case, a quartz control plate is
used, the plate should be read in the instrument under the same con-
ditions as prevailed when the plate was standardized.
(d) TYPES OF LAMPS
(1) Monoch Roma TIC.—Many different types of lamps designed for
use with the saccharimeter are available. They may be divided into
two classes—those giving a monochromatic or nearly monochromatic
light and those giving white light. In the first class only the yellow
sodium lines and the yellow-green mercury line (N=5461 A) have been
utilized to any extent and these usually for special purposes. Sources
of this type must be used for circular-scale polarimeters; they are in
general not satisfactory with saccharimeters which were designed for
the more intense white-light source.
(2) WHITE LIGHT.
Gas.-A considerable variety of lamps suitable for white-light
Sources is available both for gas and for electricity. Most of the gas
lamps utilize the Welsbach mantle, which is the source formerly most
generally used in saccharimetry. The light is convenient, has con-
siderable intensity, and the radiating surface has a nearly uniform
intensity over a sufficiently large area. A ground-glass screen may
be used close to the mantle if desired, and is necessary if the lamp can-
not be so placed as to eliminate a mottled appearance of the field
when the telescope is in focus for the analyzer diaphragm.
Electric.—The available electric lamps are of several types. A
ground-glass disk, which becomes the new source of radiation, must,
with few exceptions, be used with all types, and is preferably located
as near the radiating surface as the temperature will permit. In
figure 21 is shown an electric lamp developed at this Bureau, which
has recently been modified to carry the bichromate filter. The con-
centrated-filament incandescent stereopticon lamp for 110 volts
is used.* The area illuminated is ample for the purpose, and the
intensity sufficient. Convenience has been the chief consideration in
the design. The base B is heavy. The ground-glass disk, R, 38 mm
in diameter, is easily removable and is adjustable vertically with
respect to the body, J. Thus the filament and the disk may be kept
4 The maker’s identifying specifications for this bulb are G. E. Mazda, clear spotlight, 100 watts, 110
volts, C5 filament, P25 bulb, medium screw base.
Polarimetry, Saccharimetry, and the Sugars 84)
M
-
N– K
L-
º
t
R
E1
t-
: º
º l
2, #3-ſº
: # -:
*ā-ā-
--
! {3
ºf
5:1 !
º º: º
: ºil
r:1 -
; :
º à.j
|-t-i-
|20
| 2:
l
FIGURE 21.-Saccharimeter lamp with bichromate cell holder (NBS design).
A. base perforated for ventilation; B, cast-iron stand; C. hollow post; D, pinion for adjusting height of lamp:
E. set screw; F, solid post fitted with rack; G, glass cell; H, porcelain lamp socket; I, removable disk light
screen; J, lamp housing fitting into flange, K. L., adjustable slide; M, removable cover held by springs,
N: 0, side tube carrying ground glass and bichromate cell; P, binding posts; Q, insulating blocks; R,
flange to hold ground-glass plate; S, slot opening for ventilation.







90 Circular of the National Bureau of Standards
centered, giving uniform illumination of the disk. The cap, M.
permits the heat to pass off but no light to escape into the room,
The height of the lamp is regulated by the rack and pinion, D. The
center of the disk can thus be accurately set in the axis of the optical
system of the saccharimeter. The electric connection is made at the
binding posts, P. This lamp has proved very satisfactory in the
laboratories both of this Bureau and of the United States Customs
Service and is the type most highly recommended for general use.
The firm of Schmidt & Haensch has taken advantage of the small
size of the 6-volt lamp to mount it in an attachment which fits the
metal housing containing the polarizing system of their saccharimeter.
FIGURE 22.-White-light sources.
Left, tungsten are in vacuum (30-ampere arc); right, ribbon-filament lamp (6 volts, 108 watts).
The heat developed so near the optical parts is objectionable. The
illumination is only fairly satisfactory when the lamp is new, and the
efficiency in most cases decreases rapidly with use.
In special cases where the 100-watt lamp does not yield sufficient
light, other sources have been utilized.
The Nernst glower was useful for some years but is now of little
more than historical interest. It has been largely displaced by in-
candescent stereopticon bulbs of higher wattage than that described
above. They are obtainable in 250-, 500-, and 1,000-watt ratings.
Other high-intensity sources are (1) (fig. 22 right) the 6-volt, 108-
watt ribbon filament lamp, which is operated from a small trans-
former; and (2) (fig. 22 left) the tungsten arc in vacuo developed by


Polarimetry, Saccharimetry, and the Sugars 91
the General Electric Co. as a source for photomicrographic work.
The latter is a 30-ampere arc in a small glass bulb, the incandescent
tungsten electrode serving as the light source. It is operated by a
special high-reactance transformer operating from the 110-volt
alternating-current line. Both of these types can, by the use of
proper optical systems, be made to give uniform polariscopic fields
without the use of the ground glass, thereby greatly increasing the
intensity available. Such sources, however, find only limited uses
and for very special purposes. The 100-watt lamp described above
in detail is adequate for all ordinary work.
5. CERTIFICATION OF QUARTZ CONTROL PLATES
Quartz control plates for use in checking saccharimeters will be
accepted by this Bureau for standardization with reference to the
sugar value. The conditions as to mounting, purity of quartz, correct-
ness of fabrication, etc., are given on page 57. This Bureau
reserves the right to reject any plate showing defects which may render
it unreliable or otherwise unsatisfactory in service.
Certificates are issued showing the optical rotation of the plate
for pure monochromatic light of two wave lengths, A =5461 A and
5892.5 A, as well as the sugar value of the plate at 20° C in Inter-
national Sugar Degrees. When desired, an accompanying table of
temperature corrections will be furnished covering the range 15° to
30°C, by means of which saccharimeter readings made at any tem-
perature within that range may be corrected to the reading that
would have been obtained had the readings been made at 20° C.
6. REFERENCES
[1] H. Soleil, Compt. rend. 20, 1085 (1845); 21, 426 (1845); 24, 973 (1847);
26, 163 (1848).
2] F. J. Bates, Bul. BS 4, 461 (1908) S86; 5, 193 (1908) S98.
[3] K. Wentzke, Erdmann's J. prakt. Chem. 25, 65–84 (1842); 28, 111 (1843).
[4] Jean Baptiste Biot, Mém. acad. sci. 15, 101 (1838).
[5] O. J. Broch, Dove Rep. Phys. 7, 113 (1846). Ann. chim. phys. 34, 119 (1852).
[6] A. Girard and V. de Luynes, Compt. rend. 80, 1354 (1875).
[7] D. Sidersky, Bul. assn. chim. Sucr. dist. 3–4, 255 (1885–1886).
[8] D. Sidersky, Bul. assn. chim. Sucr. dist. 50, 355 (1933).
[9] E. Mascart and H. Benard, Ann. chim. phys. 17, 125 (1899).
[10] H. Pellet, Ann. chim. phys. 23, 289 (1901).
[11] F. J. Bates and F. P. Phelps, J. Research NBS 17, 347 (1936) RP916.
[12] O. Schönrock, Geiger's Handbuch Physik 19, 705 (1928).
[13] E. Roux, Bul. assn. chim. Sucr. dist. 55, 404 (1938).
[14] Proc. Third Session, International Commission for Uniform Methods of Sugar
Analysis, Paris, (1900).
[15] A. Herzfeld, Z. Wer. deut. Zucker-Ind. 50, 826 (1900).
[16] O. Schönrock, Z. Ver. deut. Zucker-Ind. 54, 521 (1904).
[17] Proc. Seventh Session, International Commission for Uniform Methods of
Sugar Analysis, New York, 1912.
18] F. J. Bates and R. F. Jackson, Bul. BS 13, 67 (1916) S268.
9
Sugar Analysis, Amsterdam, 1932, Int. Sugar J. 35, 17, 62 (1933).
[20] E. Gumlich, Wiss. Abhandl. physik.-tech. Reichsanstalt 2 212 (1895).
[21] T. M. Lowry, Phil. Trans. 212, 288 (1912–1913).
[22] T. M. Lowry and W. R. C. Coode-Adams, Phil. Trans. 226, 391 (1926–27)
[23] B. Tollens, Ber. deut. chem. Ges. 10, 1403 (1877).
[24] Raffaello Nasini and Vittorio Villavecchia, Public di Lab. chim. delle gabelle,
Rome, p. 47 (1891). Roma, R. Acc. Lincei Rend. 7, 285–290 (1891);
Gazz. chim. ital. 22, 97–104 (1892).
[25] Hans Landolt, Das optische Drehungsvermogen, p. 420 (Friedrick vieweg
und Sohn, Braunschweig, Germany; 1898).
[26] R. F. Jackson, Bul. BS 13, 633 (1916) S293.
92 Circular of the National Bureau of Standards
V. TEMPERATURE CORRECTIONS AND CONTROL
1. QUARTZ-WEDGE SACCHARIMETER
The question of temperature corrections for polarimetric apparatus,
as well as for the optically active substances, is a difficult one. The
literature on this subject is extensive, but it has not always been a
simple matter to select the proper correction owing to the different
results secured by various investigators. For the ordinary polar-
imeter used for measuring absolute rotations no instrument correction
is necessary. It may be used at any temperature if care is taken to
allow for any zero-point shift that may occur. However, a correction
is unavoidable for saccharimeters, in which a quartz wedge is used to
neutralize the rotation of the substance being tested if temperatures
other than the standard are used. The rotation for a plate of quartz
in the neighborhood of 20°C is given by the following:
o'- oft–H of 0.000143 (t–20). (27)
The linear coefficient of expansion of quartz perpendicular to the
optic axis is 0.000013, and of the scale is 0.000018 if it is of nickelin,
and 0.000008 if it is of glass. Thus the total temperature coefficient
[1] for the ordinary quartz-wedge saccharimeter is -
0.000143–0.000013–1–0.000018–0.000148 (metal scale) (28a)
OI’ -
0.000143–0.000013–1–0.000008–0.000138 (glass scale). (28b)
If the scales were etched on the wedges, the scale coefficient would
become zero. Since the effect of the expansion coefficient 0.000148
is to lower the reading of the scale with an increase of temperature,
the apparent polarization of any substance is lower than it should be
and the reading at 20° (S20) is given by the following:
Sºo-S,--S, 0.000148(t–20). (29)
When a quartz control plate is read in a saccharimeter, this effect
is not completely compensated. Since the temperature coefficient of
the plate is 0.000143, the reading (Sºo) of the plate is then
Soo-S,--S, 0.000005(t–20). (30)
The correction given by this equation changes sign if the scale is of
glass, and is so small at all times as to be negligible in ordinary polar-
izations.
2. SU CROSE
The influence of temperature on the specific rotation of sucrose has
been studied by numerous investigators, of whom Dubrunfaut [2] was
the first to discover that the constant decreased with increase in
temperature. Unfortunately, subsequent determinations of this
variation have not shown satisfactory agreement.
Schönrock [3] at the Reichsanstalt carried out an elaborate investi-
gation and found that for the normal sugar solution (p=23.701) the
temperature coefficient (6) was independent of the wave length of the
light used, but that it decreased with increase in temperature as
follows:
10°C, 0.000242; 20°C, 0.000184; 30°C, 0.000121.
Polarimetry, Saccharimetry, and the Sugars 93
These data show the change to be practically linear over the range
10° to 30°C, and have been combined into the following equation
|4, p. 7]: -
6= –0.000184+0.0000063 (t–20° C) (31)
3. COMBINATION OF CORRECTIONS FOR QUARTZ-WEDGE
SACCHARIMETER AND SUGARS
If a proper temperature correction is to be applied to a polarization,
it is necessary to add algebraically all the corrections applicable to the
conditions under which the polarization is being made, or to determine
the correction experimentally.
(a) SUCROSE
In the ordinary testing of sucrose, the solution is made up to volume
and read at the same temperature, which in general is not the standard-
ization temperature. It is desirable, therefore, to know the variation
with temperature in the saccharimeter reading of a near normal
sucrose solution.
Among the factors that require consideration are the changes in the
Quartz-wedge system due to changes in temperature, changes in the
specific rotation of sucrose, in the volume of solution, in the volume
of the flask, and in the length of the tube used. Some of these act in
ºte directions and thus partially cancel or compensate for each
Other.
By a summation of the best known values of the separate coeffi-
cients which enter into the correction factor, we obtain the value 0.0309
per degree centigrade for a normal sucrose solution (100° S).
Owing to its importance, this over-all temperature coefficient has
been measured experimentally by a number of investigators. Their
results are given in table 7, based upon a normal solution of sucrose.
TABLE 7.-Saccharimeter temperature coefficient for sucrose
Tempera- - Tempera-
Investigator ature Investigator ature
coefficient coefficient
Andrews------------------------------ 0.0300 || Watts and Tempany-------- - - - - - - - - - - 0.0310
U. S. Coast and Geodetic Survey - - - - - . 0.293 ºmº-º-º-º-º-º:
Wiley--------------------------------- . ()314 Average------------------------- 0.0303
GeerligS.---- - - - - - - - - - - - - - ------------- . 0300
The average value obtained is 0.0303 for a normal sugar solution
(100° S). The value varies slightly for different instruments, probably
in part because of slightly different differential expansions of the
scale and wedge mountings.
This correction factor is predicated upon the instrument and all
apparatus, flasks, tubes, etc., having been originally calibrated at
20° C but used at some other temperature between 20° and 30° C.
It is important and necessary, for the proper application of this tem-
perature correction, that the solution be made up to volume at the
same temperature as that at which it is to be read in the saccharim-
eter and that the entire saccharimeter also be at that same tem-
perature.
323414°–42 S
94 Circular of the National Bureau of Standards
Under these conditions the polarization in sugar degrees at 20°C
(S20) of an approximately normal sucrose solution made up to volume
and polarized at the same temperature (tº C) is given by the follow-
Ing:
Sºo-S,--S, 0.0003 (t–20° C). (32)
This equation is sufficiently accurate for all ordinary polarizations,
irrespective of type of tube or scale.
(b) APPLICATION OF TEMPERATURE CORRECTION BY MEANS OF A QUARTZ
CONTROL, PLATE
This correction is most conveniently and satisfactorily applied by
means of a standardized quartz control plate. The proper use of such
a plate gives an over-all correction which includes not only the
above temperature correction but also corrects any accidental or
irregular variations, such as those due to minor residual temperature
differences in the quartz wedges, etc.
The procedure in using a quartz control plate is quite simple and is
as follows:
When making a series of polarizations of sugar solutions on the
saccharimeter, also make a series of readings on the standard quartz
control plate. Observe the temperature. From the table of sugar
values for the standard plate find the sugar value corresponding to
the observed temperature. The difference between the observed
reading of the plate and the sugar value obtained from the table is
applied as a temperature correction to all polarizations made during
that series.
This is the procedure which has long been recommended by this
Bureau whenever making polarizations where a standard 20°C con-
stant-temperature room is not available.
Because of its convenience and accuracy this practice was introduced
by the Bureau into the various Customs laboratories at a very early
date. Figure 23 is a facsimile copy of a table showing the sugar
values for various temperatures of a quartz control plate, which was
issued in 1907 as a part of the certificate of test for that plate. Prior
to that date similar tables were issued and are still being issued
whenever requested in connection with the certificates for quartz
control plates. (See this Circular, p. 553, Fee Schedule 423e;
Circular C44, Polarimetry, 2d edition (1918), p. 111, Fee Schedule
44d; Circular C44, 1st edition (1914), p. 96, Fee Schedule 44d).
These tables are based upon the measured value of the plate at 20°C
and the saccharimeter temperature coefficient 0.0003, as defined
above. They are calculated from the equation
S.–S, (1+0.0003 (-20° C) (33)
and are valid, of course, only under the conditions stated above,
namely, that the solution be made up and polarized at the same
temperature.
(c) CORRECTIONS FOR USE IN TROPICAL COUNTRIES
Temperature correction by the method outlined above is frequently
utilized and gives excellent results in tropical countries, and it is
Polarimetry, Saccharimetry, and the Sugars 95
Brpartment uf (Lummerre and Tabur
Tºureau uſ $faithari`a
(ſertificate
FOR
Quartz Polariscope Control Plate
Maker: Schmidt and Haensch B. S. No. 226-8S-1907
SUBMITTED BY
Treasury Department
Washington, D. C.
Degrees Sugar Degrees Sugar Degrees Sugar Degrees Sugar
Centigrade Value Centigrade Value Centigrade Value Centigrade Value
1330 99.277 2O3O 99 298 25 30 100 313 3O3O IOO 328
1430 28O 2025 10O3OO 25.35 315 3O 25 330
152O 283 21?O 100 °Ol 26%. O 316 31?O 231
16?O 286 2135 2O3 26 35 318 3135 233
17 ?O 289 22:30 204 27.30 219 32?O $34
1725 391 2235 2O6 27 25 221 3235 $36
1830 392 23?O 2O7 28 BO 322 3330 237
1835 394 23 25 209 28.35 324 34 30 340
1930 295 24?O 210 29 30 3.25 352O 343
1935 297 2435 212 29°5 227 36:O $46


º/3. - ~. Director.
- /
Test JVo. 2633 (24- zº
Dec. 16, 1907 / ºr In charge of test.
Washington, D. C. 11–17.84
FIGURE 23.−Facsimile of certificate for quartz control plate 226–BS-1907.
96 Circular of the National Bureau of Standards
preferable to adopting a different standardization temperature, such
as 25° or 27.5°C, as sometimes suggested.
Einsporn and Schönrock [4] have made an elaborate study to find
by calculation what the corrections would be if the polarization is
carried out at the tropical temperatures of 25° and 30° C. Their
final values are identical with those which this Bureau has always
given for these temperatures in its tables of temperature corrections
accompanying quartz control-plate certificates. (See fig. 23.)
If the solution is made up to volume at 20°C, but is polarized at
another temperature, all apparatus being at that temperature,
equation 32 is no longer applicable. Under these conditions the
temperature coefficient of the normal sucrose solution alone is given
by Schönrock as 0.000469, while that of the saccharimeter, as pre-
viously shown, is 0.000148. If a glass tube is used, we have as the
total temperature correction
0.000469–0.000008-|-0.000148–0.000609.
The polarization in sugar degrees at 20° C (S20) of the near normal
solution of sucrose is therefore given by
Soo-S,--S,0.000609 (t–20° C). (34)
Equation 34 obviously holds only while the number of grams of sugar
in 100 ml of the solution remains unchanged.
(d) SUGAR MIXTURES
The coefficient 0.0003, in eq. 32, having been determined for the
normal weight of sucrose, should be applied with considerable care.
It has, however, long been a widespread practice to apply it to all
Sorts of Saccharine products, with the result that a polarization,
supposedly accurate, may contain errors of appreciable magnitude.
If the solution does not read approximately 100° S, the correction to
give the reading at 20° C should not be obtained by multiplying 0.03
by the difference in temperature—a common practice. In general,
no great error will be introduced by following this procedure provided
the polarization is above 85° S. Nevertheless, the better and safer
practice is to solve eq 32, thereby correcting for the difference in
Sucrose concentration from the normal solution.
An even more widespread practice has been to apply eq 32 to sugar
polarizations without regard to the associated impurities. This is
particularly true of raw sugars and molasses which contain appreciable
quantities of invert sugar. Of the constituents of invert sugar, the
dextrose has a negligible temperature coefficient, while the levulose
has a very large coefficient, and in such a direction that the positive
rotation of the mixture tends to increase upon elevation of temperature.
It is therefore manifestly erroneous to apply a pure sucrose tempera-
ture coefficient to a mixture unless all the substances, except sucrose,
are present only in such small quantities that the error introduced is
negligible.
For the temperature correction of the better grades of raw sugar,
the temperature formulas 32 and 34 give results which are sufficiently
accurate; but if they are applied to low-grade products, errors are
Polarimetry, Saccharimetry, and the Sugars 97
introduced. Raw sugars may be considered as mixtures of pure
sucrose and cane molasses. To correct the whole mixture for the
effect of temperature, change, it would be necessary to apply the
resultant coefficient obtained by combining the separate coefficients
for sucrose and for molasses, taking into consideration the relative
quantities of the two and the constitution of the particular molasses
which contaminates the sample. C. A. Browne [5] has done this
and shows that the temperature coefficient varies in almost direct
proportion to the content of molasses. It is in general incorrect to
apply this computed correction because of possible individual varia-
tion in the constitution of the molasses. Accordingly Browne advises
the omission of the temperature correction for low-grade samples. He
has computed an average coefficient for large numbers of samples of
raw sugar which may be determined according to the polarization.
Thus for cane products the coefficient is 0.0015. It is seen from this
that at 80° the coefficient becomes zero and for lower grades it becomes
positive instead of negative. If individual variations did not occur,
this correction would be a useful one; but as it stands, it merely serves
to show the possible error of applying eq 32 to low-grade sugar.
For beet products the coefficient is 0.0006.
4. THERMOSTATS
(a) WATER
The satisfactory control of temperature in polarimetric work is
an important and troublesome subject. For accurately making up
solutions to volume at a desired temperature, water thermostats
which give extremely close regulation are to be preferred. Many
types which are entirely satisfactory are available from apparatus
dealers. These consist essentially of metal or glass tanks suitably
insulated on the outside and nearly filled with water. The cooling
is accomplished by circulating ice water through an immersed coil,
and the temperature regulation is maintained by immersed lamps or
heaters operated intermittently by means of mercury relays connected
to mercury thermoregulators. The water is kept in constant motion,
insuring an even temperature throughout, by means of electric tur-
bines or stirrers. For circulating constant-temperature water through
the jackets of polariscope tubes, refractometers, etc., use is made of
small electric-driven pumps.
(b) AIR
At the National Bureau of Standards most polariscopic measure-
ments are made in a constant-temperature room maintained at the
standard temperature of 20° C. Three such rooms are available.
The largest of the three, used for both routine and research work, is
approximately 10 by 20 feet. The walls and ceiling are insulated with
thick corkboard. The temperature is maintained by the automatic
intermittent operation of a large ammonia compressor located in the
attic room above, the direct-expansion ammonia coils being mounted
on the side walls of the constant-temperature room. Satisfactory
temperature control is accomplished through the use of a bimetallic
regulator.
The saccharimeters are placed within the room on a table of con-
venient height. For special work the instruments are enclosed in
98 Circular of the National Bureau of Standards
individual insulated boxes. This so retards any change in temperature
of the instrument that, when the room is operating within a few tenths
of a degree, no significant change can be detected on the thermometer
inside the instrument case after equilibrium is reached. The illumina-
tion of the instrument is secured by placing suitable light sources just
outside the room, allowing the light to pass into the room through small
glass windows in the walls.
One of the rooms used for special research work, in which the
Bureau's large polariscope, described on page 46, is located, is
approximately 7 by 10 by 9 ft. with an adjoining closet in which is
housed refrigeration coils feeding from the central refrigerating system
(CO2) of the Bureau and controlled by
a needle valve on the intake side
(fig. 24). A fan, F, located in an
opening near the top of the closet blows
cold air from around the refrigera-
tion coils, RC, out into the room into
the space above a false ceiling, C, which
|O' is perforated throughout and serves to
distribute the cold air evenly over
the top of the room. An opening
near the bottom of the closet allows
return air to be sucked into the closet
to be recooled. Cold air is prevented

7. from circulating in reverse direction,
when the fan is not operating, by
F means of a valve, V, consisting of aflap
CH C of heavy cloth tacked across the upper

T- edge of the bottom opening. When
% the fan stops, the cloth falls against
, the opening and effectively seals it
9 against the cold air in the closet.
ſ Thus cold air is fed into the room
V
only while the fan is operating and in
an amount depending upon the speed
§ of the fan.
7. A heater, H, attached to the lower
Figure 24.—Constant-temperature side of the false cºiling may be operated
TOO770. when needed, either continuously by a
Upper, basal section; lower, vertical Section. switch or automatically by a thermo-
stat. This heater is used, however,
only when temperatures above outside room temperature are
required.
The fan which controls the amount of cold air put into the room is
operated automatically by a bimetallic-strip regulator through an elec-
tronic relay. This avoids the use of all mechanical relays and their
troublesomeness.
The assembly used for operating the fan is shown in figure 25 and
is largely self-explanatory.
It is essentially a full-wave grid-controlled rectifier arranged for on
and off or relay operation. It was assembled from stock parts which
were immediately available, with a view to extreme flexibility and
adaptabilitv to other uses. Had it been engineered only for the par-
Polarimetry, Saccharimetry, and the Sugars 99
ticular job in hand, considerable simplification could have been made.
For instance, the variac, T., could have been dispensed with and also
a much smaller transformer of the correct voltage and power rating
used in place of T. However, the apparatus as assembled has proved
Very convenient and dependable in operation and has a power-handling
ability of over 500 watts. - --
In operation, current is first switched onto the filament lighting
transformer, T., and the filaments of the FG 57's allowed a heating
time of about 5 minutes before switching on the plate power, T.
For the sake of simplicity of the drawing, the filaments are shown
lighted by separate transformers. In practice they may just as well
be paralleled on a single 5-volt winding.
After the filaments have reached their operating temperature,
the switch, S, is closed, activating the variac, T, whose output tap
FIGURE 25.-Wiring diagram for electronic-relay control of thermostated cold room.
T, GR Variac, 200 CM; output voltage, 0 to 130 volts; T., GE transformer No. 9TM416A; primary 683
kilovolt amperes, secondary 990 kilovolt amperes, 110/220/55 to 550/275 volts; T3, Filament transformer,
110 to 5 volts, 50 watts; S, Fuse and switch; VT, Thyratrons FG 57; plate current, 2.5 amperes each, maxi-
mum average; 1,000 volts, maximum peak; filament, 5 volts, 4.5 amperes each; R1, 20-ohm resistors (660-
watt heater units with medium screw base) mounted in porcelain lamp-socket bases; R2, 50,000-ohm,
l-watt resistors; R3, 100,000-ohm, 1-watt resistor; R4, 10,000-ohm, 1-watt resistor; C. 1-microfarad capaci-
tor; B, 7.5-volt bias battery; K. American Instrument Co. “Quickset” bimetallic regulator; V, Direct-
current voltmeter, for use when adjusting the load voltage bw means of Ti; O, Hubbell plug which serves
as output terminals; F, Fan located in cold closet; and W, Twisted lamp cord leads.
has been set at or below the proper operating position for the particular
load, which is connected through a Hubbell plug at O. When first
adjusting the apparatus, the voltage on the primary of T, is varied by
means of the variac, Ti, until the direct-current voltmeter, V, shows
the correct voltage across the load at O, which in this case is the fan
motor, F. Thereafter the variac may be left at its proper setting and
the power simply switched on at S. -
For the particular fan at present in use, about 70 volts is required
OT). } input side of T, to maintain the fan's rated voltage of 120 volts
at 0.
The resistors, R1, are ballast resistors to protect against current
surges and extreme overload on the tubes made possible by the non-
resistive character of the load (fan motor). Even if the load were
short-circuited, RI would limit the current to the point where the tubes
and transformer would not be injured before the fuse could blow or an
overload relay, if used, could operate. Heater units, 110-volt 660-
watt, such as are used in the ordinary household electric reflecting
heater, serve admirably. They consist of resistance wire wound on
a ceramic cone which carries a screw plug on one end similar to that on
ordinary incandescent lamps and which fits the ordinary medium
screw-base lamp socket.
:
:

100 Circular of the National Bureau of Standards
Load current is not passed by the tubes as long as the grids are kept
sufficiently negative. When the contacts of the bimetallic regulator,
K, are open the grids assume practically ground or cathode potential
and load current normally flows, operating the fan. When sufficient
cold air has been blown into the room to cause the contact, K, to
close, the battery, B, operating through the networks R,R,R, im-
presses a negative bias on the grids sufficient to block off the plate
current and stop the fan. Since this battery, which is an ordinary
7%-volt radio C battery, is only connected in the circuit intermittently,
and then through a high resistance of more than 100,000 ohms, its
expected life is not much less than its shelf life.
The condenser, C, serves to stabilize the grid-cathode difference of
potential and at the same time, in connection with R, and Ra, serves as
a time-delay device, to delay starting or stopping until after K makes
good contact or breaks contact. This aids in eliminating chattering
due to mechanical vibrations when the contacts, K, are nearly closed.
Ra serves to discharge Cafter K opens, thus allowing the grid to return
to cathode potential and start the fan. R, serves to limit the rush of
charging current to C when K closes, preventing sparking at the con-
tact, K. By use of this device the temperature of the room may be
maintained constant at any desired temperature within the range
of the cooling system, for long periods of time, with a variation of only
a few tenths of a degree. The exterior walls of the room are cork-
insulated. Provision also is made for cooling the room in wintertime
by the use of outside air instead of refrigeration, by blowing the cold

Polarimetry, Saccharimetry, and the Sugars 101
outside air through a duct into the room. The fan for this also may
be plugged in at O and operated thermostatically either instead of or
in parallel with the fan in the cold closet. Lamp-cord connections
are used at W and permit the relay to be located at any convenient
place, since their length is immaterial.
The air bath (fig. 26) on the polariscope mentioned on page 46 is
located in this room. In operation the room temperature is set at
from one-half to 1% degrees below that desired in the polariscope
thermostat. The temperature of the latter is then brought up to and
maintained at the desired temperature, usually 20°C, by an electric
heater whose windings are fairly uniformly distributed around four
surfaces of the box, as indicated in the photograph. A slight increase
R
3
i
•.
i-
NIOV
x-
:
T
- |OV i. 22OV
FIGURE 27.-Wiring diagram for electronic relay control of polariscope air bath
(fig. 26).
Ti, 110- to 220-volt transformer, about 100 watts; T2, Filament-lighting transformer, 110 to 5 volts, 4.5
amperes; T3, Biasing transformer, 110 to 10 volts, 0.1 ampere. Note that T2 and T3 may conveniently be
separate windings on Ti; VT, Thyratron FG 57; R1, 50,000-ohm, 1-watt grid resistor; R2, 1-megohm, 1-watt
resistor; R3,200-ohm potentiometer (not needed if T is supplied with a mid-tap); L, Lamp sockets for the
insertion of different-wattage lamps as series resistance for H; H, Heater-winding in thermostat; MC,
Mercury-platinum contact contained in 1-mm capillary tube connected to toluene coil; and W, No. 20
lamp-cord leads to mercury contact.
T2
/
R
in temperature causes toluene in the glass tubing, fig. 26, to expand and
close the mercury contact, MC, figure 27. This figure shows the wiring
diagram for the relay and heater. The transformer, T3, working
through the resistors RIR2R3, when MO is closed, impresses a negative
bias on the grid of the Thyratron, VT, sufficient to block off the plate
current. When MC opens, this negative bias is removed and plate
current again passes, since the grid potential then becomes 0 or posi-
tive, according to the position of the tap on Ra. If a 10-volt middle-
tapped transformer is available, R3 is not necessary.
The heater, H, and the mercury contact may be seen in the photo-
graph. The lamps, L, are outside the thermostat and serve to control
the current in H without the necessity of varying the input voltage
to T. Ordinarily a single 50-watt lamp gives about the right amount
of series resistance, since only a few watts are required in H when the
surrounding temperature is only about 1° below that of the thermostat.
The air in the thermostat is stirred by means of a fan driven by a small
electric motor. The temperature remains constant to 0.01° C or

102 Circular of the National Bureau of Standards
better. No variation can be seen on a 0.1° thermometer read by a
telescope, where 0.01° C would readily be detected. There are no
moving contacts to give trouble, and this relay has been left in opera-
tion for months at a time with no attention whatever. The current
made and broken at the Hg-Pt contact, MC, has been reduced to a
very small value, which largely eliminates contamination of the mer-
cury due to arcing or sparking. If a screen-grid Thyratron, such as
the FG 95, is used in place of the FG 57, the resistance in series with
the contacts, MC, may be increased to several megohms without loss
of reliability, still further reducing the current in MC.
Recently a third constant-temperature room has been installed,
designed to permit polariscopic measurement over a wide range of
temperatures. The room is insulated by a 6-inch layer of cork on
all walls, ceiling, and floor; the inner surface is finished in cement
plaster on the walls, and thick cement floor. In the attic above is
located a large insulated brine tank, cooled by immersed coils con-
nected to the central system of liquid CO2 refrigeration. The cold
brine is circulated through cooling coils mounted in the constant-
temperature room by means of an electrically driven pump. The
circulating pump may be run intermittently by a thermostat or con-
tinuously as desired. The cooling coil in the room is mounted in a so-
called cooler placed near the ceiling. A large fan located in the cooler
forces air over the coils and distributes it through a duct running the
length of the room. The duct is fitted with suitable adjustable
openings, permitting even distribution of the cooled air. A thermo-
regulator controls the pump which circulates the brine through the
coolers. Other thermostats control heaters mounted within the duct.
Constant temperatures may be maintained within the room over a
temperature range of from –30° to +30° C.
5. REFERENCES
[1] O. Schönrock, Z. Ver. deut. Zuckerind. 54, 521 (1904).
[2] Dubrunfaut, Ann. chim. phys. [3]. 18, 99, 107 (1846).
[3] O. Schönrock, Z. Ver. deut. Zuckerind. 50, 419 (1900).
[4] E. Einsporn and O. Schönrock, Z. Ver, deut. Zuckerind. 89. 1 (1939).
[5] C. A. Browne, J. Ind. Eng. Chem. 1, 567 (1909).
VI. ACCESSORY APPARATUS
1. POLARISCOPE TUEES +
(a) TYPES
(1) ORDINARY. —There are available at present a variety of polar-
iscope tubes each designed to give satisfactory results under certain
conditions. In making a selection, the user must be guided by his
own particular needs. In general, polariscope tubes should be con-
structed to meet three essential requirements, and if these are not
met by the device as furnished by the maker, the faults cannot be
remedied by the user. These requirements are (1) parallel ends which
are perpendicular to the axis of the tube, (2) accurate length, and (3)
accurate centering of the axis of the tube in the trough of the saccharim-
eter. In most instruments the center of the optical path is approxi-
mately 15 mm above the bottom of the trough. The type for ordinary
*See test-ſee Schedule 297, p. 555.
Polarimetry, Saccharimetry, and the Sugars 103
polarizations at temperatures not far removed from 20°C is the sim-
plest, but, unfortunately, has received least consideration. Its design
should have careful study, even to the slightest detail. This is essen-
tial owing to its widespread and constant use for both scientific and
commercial purposes.
An all-metal tube of small bore (fig. 28, No. 4), being one type that
is in more or less general use, has the same diameter for the entire
length. These tubes frequently are constructed with walls so thin
that they are easily bent or distorted, resulting in a change of length
and ruining the tube. In many cases the bore is too small. The
diaphragming in the modern saccharimeter is designed to give the
highest possible illumination of the field. To utilize this as well as
to eliminate the undesirable “halo” in the field of the instrument, it is
necessary that the bore have a diameter of not less than 9 mm. Con-
siderable time is lost in filling owing to the fact that the tube must be
so completely filled that no air bubble remains. The weight of the
tube is carried upon the caps which hold the cover glasses. If the
tube is rotated in the trough of the instrument, the caps may be
tightened, and the additional pressure may cause double refraction
in the cover glasses, which has the effect of changing the rotation
of the plane of polarization.
Glass tubes must be used when the solutions contain acid or other
corrosive chemicals. Metal collars threaded to fit the screw caps are
cemented on. Wax is sometimes used for this cementing, but this is
objectionable on the ground that the wax sometimes softens and
permits the collar to be displaced until it extends over the end of the
tube. Thus the length of the column of liquid being polarized is
increased and an error introduced in the observation. A mixture of
glycerine and litharge or a similar cement is more satisfactory, and
the ends of the glass tube should not extend more than 1 mm beyond
the threaded collar.
(2) BATES.-In the laboratories of the U. S. Customs Service, as
well as in other laboratories, there is required a tube which is both
rugged and as free as possible of defects. The Bates tube (fig. 28,
No. 1) designed at this Bureau, has proved to be entirely satisfactory
in meeting these requirements. It will be observed that the weight is
carried upon two shoulders, which are integral parts of the tube, and
not upon the caps, thereby eliminating all danger of tightening when
the tube is rotated in the trough of the instrument. The bore is 9
mm, permitting the utilization of the full aperture of the polarizing
system. This also reduces to a minimum the light depolarized by
reflection from the walls of the tube. The field of the instrument
appears as a bright circle with no overlying haziness, and permits
readings of increased accuracy. Both ends are enlarged with all the
attendant advantages; hence but one size cover glass and washer is
required. The walls are unusually heavy, eliminating all danger of
bending. These tubes are available in 400-, 200-, and 100-mm
lengths. Glass tubes of the same design are also in general use.
(3) SPECIAL.-There are a number of tubes available for special
purposes. For polarizations, where the temperature must be con-
trolled or measured, a water-jacketed tube is recommended (fig.
28, No. 2). This consists of an inner tube of either metal or glass
having a tubulature midway between the ends to permit filling and
inserting a thermometer. A watertight jacket of metal surrounds
104 Circular of the National Bureau of Standards
the inner tube provided with a nipple at each end to allow the circu-
lation of hot or cold water. Landolt has designed a glass tube with
one end enlarged and having sliding caps which fit over metal mounts,
this construction being intended to eliminate the possibility of exces-
sive pressure on the cover glasses. This tube has been modified by
having the caps held in place by bayonet catches. However, the
Landolt tube has not been generally used in the United States. Tubes
provided with screw caps are preferred by most chemists, and if care
is taken not to tighten the caps too much, they are entirely satisfactory.
|I 11||
º
ſ º/t
j
Lºlº, |
& º ºn º º & º º º 'º º ºsº º º
º 5% cº-
5 6
FIGURE 28.- Polariscope tubes.
The continuous-flow tube of Pellet (fig. 28, No. 3) is widely used in
factory control work. It is provided with a tubulature at each end,
permitting filling and emptying without removing the tube from the
instrument. The tube is filled by pouring the solution through a
small funnel into one of the tubulatures. After the polarization, the
succeeding solution is poured into the tube, displacing the first
solution. These tubes effect a saving of time and are satisfactory for
use with solutions of approximately the same polarization. Yoder
devised a volumetric tube having the graduation mark on the connec-





Polarimetry, Saccharimetry, and the Sugars 105
tion joined on the middle of the tube. The usual size is 10 ml, but
º, of various volumes may be constructed by varying the length
and bore.
When the temperature of the solution is below the dew point,
moisture condenses on the cover glasses. Wiley has overcome this
by an ingenious desiccating cap (fig. 28, No. 6), which carries calcium
ºride or other desiccant, and screws to the end of the polariscope
tube.
A special glass-lined Bates tube is shown in figure 28, No. 5. It is
made in 50- and 25-mm lengths and is useful in cases where a limited
volume of liquid is available or where high rotating liquids are to be
measured.
(4) WATER-JACKETED FOR HIGH-TEMPERATURE POLARIZATION.—
It is frequently necessary to make polariscopic observations at high
temperatures. Difficulty has been experienced in such measurements,
using the ordinary water-jacketed tubes, due to leakage and distortion
of the field caused by uneven heating. There has recently been
developed at this Bureau a tube designed to eliminate the existing
defects. The new tube, figure 29, is constructed entirely of an iron-
nickel alloy having practically zero expansion for temperatures from
| _l
|
0° to 100° C. The tube is welded into a water jacket which extends
well beyond the end of the inner tube, thus maintaining an even
temperature throughout the length of the liquid-column under obser-
vation. The tube is provided with a tubulature for the insertion
of a thermometer.
(b) TEMPERATURE CORRECTIONS
FIGURE 29.-High-temperature polariscope tube (NBS type).
It is customary to determine the exact length of polariscope obser-
vation tubes at the standard temperature of 20° C. The length of
any tube at any temperature may be obtained by the following formula:
L,- Loo [1+B (t–20° C)], (35)
where Loo is the length at 20°C and 6 is the coefficient of linear expan-
sion of the material of which the tube is made. For glass, 8–
0.000008, and for brass, 3–0.000019. From eq 35 for L20–200,
Lao–200.016 for glass and 200.038 for brass. It is evident that the
errors resulting from changes in length of tubes of either material are
negligible in ordinary use, but it is customary to apply the correction
in all precision measurements. -
(c) ACCURACY
All types of polariscope tubes are accepted by the Bureau for test.
The tolerances adopted by the National Bureau of Standards for
polariscope tubes are given in table 8.

106 Circular of the National Bureau of Standards
TABLE 8.—Tolerances for polariscope tubes
Length Tolerance
IIl II, IIl II.
400 ––0.04
200 +. ()3
I ()() +. 03
50 +. 03
25 +. 03 .
2. COVER GLASSES*
Glass which is not free from strain is doubly refractive, and on this
account should not be used between the polarizing and analyzing
systems of a polariscope. It is therefore of great importance that
cover glasses be made of optical glass and thoroughly annealed. A
strain in the cover glass is in effect a rotation, a cause of many baffling
discrepancies that occur in polarizations. There is no infallible
method of detecting this trouble after the glass is in use, the only safe
procedure being to use cover glasses which have been tested, and to
put as little pressure as possible on the screw caps. After a setting
has been made, it is advisable to rotate the tube in the trough of the
instrument; if the halves of the field show variations in intensity,
strain exists in one or both of the glasses. Strains may be caused by
poorly fitting rubber washers. These should be made from the best
Quality rubber, soft and flexible. They should be made of such size
that they lie flatly and evenly in the cap with no marginal elevation.
Once a glass has been strained, it should not be used for several days
or until test shows the absence of strain. All cover glasses must have
plane, parallel surfaces, free from scratches, and should never be less
than 1 mm thick. A thickness of 1.5 to 2 mm is preferable. The
necessity for optically perfect glasses has not received the attention its
importance demands. The cover glasses used in the laboratories of
the National Bureau of Standards for Bates-type polariscope tubes
conform to the following specifications:
“Cover glasses shall be made from clear, colorless optical glass,
thoroughly annealed, free from strain, and shall show no optical
rotation or double refraction when observed in a precision polarimeter.
The surfaces shall be plane and parallel and be free from scratches.
The edges shall be slightly rounded to prevent chipping. Plane
parallelism shall be within 5’; thickness 1.85 + 0.15 mm; diameter
23.2 + 0.2 mm.” The National Bureau of Standards will accept
polariscope tube cover glasses for test.
3. VOLUMETRIC FLASKS**
(a) SPECIFICATIONS
(1) MATERIAL AND ANNEALING.-The material should be the best
Quality of glass, transparent, and free from bubbles and striae. It
should have small thermal hysteresis and should adequately resist
chemical action. All flasks should be thoroughly annealed before
being graduated.
(2) DESIGN.—The cross section of the neck must be circular, and
the shape of the flask must be such as to admit of complete emptying
*See test fee schedule 423, p. 553.
**See test fee schedule 241, p. 558.
Polarimetry, Saccharimetry, and the Sugars 107
and drainage from the whole interior surface at the same time. The
bottom of the flask should be slightly concave upward and should be
of sufficient size to enable the flask to stand on a surface inclined at
an angle of 15° to the horizontal. The neck must be cylindrical for
at least 1 cm on each side of every graduation mark, but may be
enlarged in the form of a bulb between graduation marks (for example,
Giles flasks). At the graduation mark the inside diameters of the
neck of the flask must be within the limits given in table 9.
TABLE 9.—Diameters of necks and tolerances for volumetric flasks
Capacity Diameter of neck Tolerance—
of flask
up to and
including—| Maximum | Minimum | If to contain | If to deliver
Tml 77,777, 77,772 Tml ml
10 || -------- -------- 0.01 0.02
25 8 6 . 03 05
50 10 6 . 05 10
100 12 8 08 15
200 14 9 10 20
250 15 10 12 25
500 18 12 15 30
1,000 20 14 30 50
2,000 25 18 50 1. ()()
(3) GRADUATION MARKs.—The graduation marks must be of uni-
form width, finely but distinctly etched, must be perpendicular to
the axis of the flask, and must extend completely around the neck.
On flasks having a capacity of 100 ml, or less, the graduation mark
shall be not less than 3 cm from the upper end, nor less than 1 cm from
the lower end of the neck, and on flasks having a capacity of more than
100 ml, the graduation mark shall be not less than 6 cm from the upper
end, nor less than 2 cm from the lower end of the neck.
(4) UNIT OF VolumE.—The unit of volume employed is the liter,
which is defined as the volume occupied at the temperature of its
maximum density (4° C) by a quantity of pure water having a mass of
1 kg. The water is under a pressure of 760 mm of mercury, and the
weighings are reduced to vacuo. The one-thousandth part of the
liter, called the milliliter (ml), is also employed as a unit of volume.
(5) STANDARD TEMPERATURE.-Twenty degrees centigrade has been
adopted by the Bureau as the standard temperature for volumetric
apparatus, and an extra charge is made for testing apparatus for use at
other temperatures.
(6) INSCRIPTIONS.–Each flask must bear, in permanent and legible
characters, the capacity in liters or milliliters, the temperature at which
it is to be used, the method of use, i. e., whether to contain or to deliver,
and an identification number. In the case of flasks with stoppers, the
stopper must bear the same number as the flask, or, if standard inter-
changeable grindings are used, they must bear the proper identification
marks. A suitable arrangement of the inscription is as follows:
No. 134
Contains
100 ml
at 20° C.
108 Circular of the National Bureau of Standards
(b) TOLERANCES
The tolerances for flasks of various sizes are shown in table 9.
(1) PRECISION STAMPs.-Flasks tested by the National Bureau of
Standards and found to comply with the foregoing specifications will
be given the official precision stamp of the Bureau. The stamp con-
sists of the letters “NBS” and the year in which the test is made,
surrounded by a circle. Thus for the year 1941 the stamp will be
NBS
I941
The ºny will be placed on the neck of the flask, above the graduation
IQ 8.I’K.
(2) SUGAR-TESTING FLASK (BATEs).-The type of flask used in the
sugar laboratories of this Bureau and in the United States Customs
Service is shown in figure 30, No. 1. It is especially designed for sugar
polarizations and is described in the Customs Regulations, 1931,
chapter XI, Sampling, Weighing, and Testing of Sugars, Sirups, and
Molasses, as follows: “The flasks shall have a height of 130 milli-
meters, the neck shall be 70 millimeters in length and have an internal
diameter of not less than 11.5 millimeters and not more than 12.5
millimeters. The upper end of the neck shall be flared, and the grad-
uation marks shall be not less than 30 millimeters from the upper end
and 15 millimeters from the lower end of the neck.” All flasks shall
be standardized to contain 100 ml at 20° C. These specifications
permit a maximum internal diameter of the neck of 12.5 mm, which
exceeds the maximum allowed in the National Bureau of Standards
specifications for 100-ml precision flasks by 0.5 mm. However, since
the sugar flask is used almost exclusively for polariscopic work, it is
tested as precision volumetric apparatus, and if the tests show it to
be in accordance in all respects with the specifications given above, it
* º given the precision stamp of this Bureau, described under (b)
(1) above.
In the Bates type of flask the neck, while smaller than that of the
ordinary 100-ml sugar flask, is made slightly larger than the Bureau's
requirements for a flask of this size in order that the neck shall not
become clogged when the sugar is being introduced into the flask.
The upper end is flared to facilitate pouring. The height of only 130
mm minimizes the dilution of the solution by moisture on the upper
part of the neck and gives a length which readily permits the flask to
be closed with the thumb while the forefinger rests on the bottom,
...; facilitating a thorough mixing by shaking, with no loss by
Sp1111ng.
(3) SPECIAL.-A number of flasks designed for special purposes are
shown in figure 30. -
Flask 1 is the Bates-type sugar flask, specifications of which are
given above. This flask is used extensively in the United States
Customs Service and elsewhere in routine sugar analysis.
Flask 2 is the Kohlrausch flask with a funnel neck to facilitate the
transfer of the solid sugar without loss.
Polarimetry, Saccharimetry, and the Sugars 109
Flask 3 is typical of the double-graduated flasks and is used in
inversions and clarification methods where one volume is to be diluted
to a different volume. The usual sizes are 50–55, 100–110, 200–220,
and 500–550 ml.
Flask 4 was designed at the National Bureau of Standards for
precision work. The inside diameter of the neck is 5 to 6 mm. The
enlarged portion of the neck permits complete mixing of the contents
of the flask without the solution coming in contact with the grinding
or the thumb until the mixing is complete. Before making to volume,
the bulb is dried inside by a current of filtered air. The glass tube
is ground to fit the grinding of the flask and also the glass stopper of
the tubulated water-jacketed polariscope tube, which permits the
transfer from flask to polariscope tube without exposure to the air
and the consequent evaporation of the solution. In addition to the
100-ml mark on the neck of the flask, there are supplementary gradu-
ations above and below the mark. With this flask it is possible to
|
No. 6
CONTAINS
100nt.
• 20°C
No. 2
CONTAINS
100ml.
• 20°C
No.3
CONTAINS
Pił.
No. 1 N O.2 No.3
FIGURE 30.-Volumetric flasks.
No.6
make the calibration and reproduce the volume of solution with an
accuracy of 0.002 ml.
Flasks 5 and 6 are special flasks used chiefly in the determination
of the density of molasses and sirups.
(4) CoRRECTION TABLEs.-Tables 106 and 107, p. 612, are given
for the convenience of those who wish to verify the graduation of
volumetric apparatus. More complete data for this purpose will be
found in National Bureau of Standards Circular C19.
4. THERMOMETERS*
(a) GENERAL
Thermometers [1] should be of good design and workmanship and
should be made of suitable materials, with special attention to the
thermometric properties of the glasses used. Detailed specifications,
covering the necessary items for the various types of thermometers
suitable for use in polarimetric measurements, have been prepared
and are available upon request. A sample form of the specifications
is printed in this circular, page 382.
*See test-fee schedule 311, p. 554.
323414°–42 9








110 Circular of the National Bureau of Standards
Mercury-in-glass thermometers are calibrated to agree as closely
as possible with the International Temperature Scale adopted in 1927
and now in general use. On this scale, which conforms with the
Centigrade Thermodynamic Scale as closely as possible with present-
day knowledge, temperatures in the interval — 190° to 660° C are
defined in terms of the resistance of a standard form of platinum
resistance thermometer calibrated at basic fixed points. The Inter-
national Temperature Scale is defined in NBS Research Paper
RP22 [2].
It is highly desirable that a fixed point appear on the scale of a
mercury-in-glass thermometer. The ice point (0° C or 32° F) or
steam point (100° C or 212° F) is convenient. The volume of the
bulb of a mercury-in-glass thermometer is known to change with
time and use by amounts which must be taken into consideration if
the best results are to be obtained. By checking the fixed-point read-
ing from time to time, these changes may be determined and allowed
for. For example, if the ice-point reading is found to be higher Or
lower than the previous reading, all other readings on the thermometer
will be higher or lower by the same amount.
Thermometers provided with graduated metal backs should, in
addition, have graduations engraved on the glass stem. The ther-
mometer should be securely and firmly fastened to the back. If the
thermometer is of the inclosed-scale (Einschluss) type, such fiducial
mark should be placed on the outer glass tube.
Thermometers should comply in all respects with the applicable
specification.
(b) ICE BATHS [3]
Because of the changes in bulb volume, the ice bath, which provides
a convenient means of determining the amount of such changes, is
very important. The most convenient form consists of a wide-
mouthed thermos bottle or Dewar flask, filled with a mixture of
shaved ice and distilled water, or water obtained by the melting of
the ice. Other containers may be used, but are likely to be less
convenient because of the more rapid melting of the ice. Clear ice
is considered sufficiently pure for the purpose and is readily obtainable.
The ice may be shaved by means of a small plane, resembling a car-
penter's plane, or other appropriate mechanism. There should be
enough water in the mixture to make it soft or slushy, but not enough
to cause the ice to float. Excess water which accumulates may be
conveniently removed by means of a glass siphon, ending in a rubber
tube with a pinch cock. Precautions should be taken to wash the
ice and to avoid contaminating it in handling.
5. WEIGHTS”
(a) SUGAR
It is generally advantageous to have special 26- and 13-g weights
for weighing out sugar samples for direct polarization. For this work,
the Bureau recommends that the ordinary screw-knob type of weight
be avoided in favor of a strictly one-piece weight in which the knob
forms an integral part of the weight. Gold- or platinum-plated
Tobin bronze weights have been found satisfactory. Recently,
*See test ſee Schedule 226, p. 557.
Polarimetry, Saccharimetry, and the Sugars 111
stainless-steel weights have been introduced, and the indications are
that they will prove satisfactory if made from steel of the proper
composition. The working standards should conform to the Bureau's
requirements for class B and the reference standards (i. e., those used
only for checking the working standards) should conform to the
requirements of class A. The maximum error allowed in both classes
is 2 mg on the 26-g weight and 1.5 mg on the 13-g weight.
(b) ANALYTICAL
In most analytical procedures in the sugar laboratory, a good grade
of analytical weights should be accurate enough, but it is not safe to
rely on them unless they are tested. For work requiring considerable
accuracy in the weighing, the weights should conform to the Bureau's
requirements for class S. The maximum errors allowable range from
0.5 mg on the 100-g weight to 0.1 mg on the 1-g weight and 0.02 mg
on the 10-mg weight. For less accurate work, weights conforming
to the requirements of class S2 having allowable errors of five times
those of class S, may be used.
(c) REFERENCE STANDARDS
Weights are liable to change. They cannot be used without a
certain amount of wear, which will ultimately make an appreciable
change in their values. Ordinary analytical weights sometimes
suffer serious change from the oxidation of adjusting material placed
in the cavity under the knob. Weights must therefore be retested
from time to time according to the nature of the weights and of the
work for which they are used. Reference standards are therefore
needed, since it is seldom advisable to send the weights to this Bureau
as often as would be needed. There is no gain in the purchase of
complete sets for this purpose when this is done at the expense of
quality, as must usually be the case. A set of working standards can
be tested readily by intercomparison of the weights among themselves,
if one or two reference standards are available on which to base the
calibration. The Bureau will furnish information in regard to series
that are much better than the ones generally used and yet involve
no great amount of additional labor. Probably the best denomina-
tions for reference standards would be one 100- or 50-g weight, one
1-g weight, one 10-g weight, one 26-g weight, and one 13-g weight.
The 1-g weight should be made of platinum, as it is the starting point
for the determination of the milligram weights.
For the best reference standards, the Bureau recommends one-piece
weights. Gold- or platinum-plated Tobin bronze weights are the
most satisfactory ones now available for this purpose for weights
above 1 g. Weights having a hard metal driven plug would rank
next. Standards for the analytical sets should conform to the require-
ments for class S and be tested under that class." Reference standards
for the “sugar weights” should come under class A, as stated above.
(d) CERTIFICATION
Sugar weights and analytical weights are among the weights tested
by the Bureau, but the rougher weights are not regularly accepted
for test.
* The Same kind of weights, but less accurately adjusted, may be obtained as class 4 and class B weights.
For extreme accuracy (seldom, if ever, needed in weighings for polarimetry), when careful corrections
must be made for the buoyant force of the air, only one-piece weights can be relied upon, and the volume of
each weight must be determined. This requires that the weights come under class M.
112 Circular of the National Bureau of Standards
Information as to the precision to which corrections will be certified
for weights of classes A, M, or S, and lists of tolerances for any class,
will be supplied on application to this Bureau. Full details as to
specifications, tolerances, and precision of corrections, together with
other information as to standard weights and some of the methods of
testing them, are given in National Bureau of Standards Cir-
cular C3.
To assist in the identification of the weights, the test number assigned
to the weights by the National Bureau of Standards will be stamped
on the bottom of the box provided for keeping them, thus NBS
Test No. 4978.
The shipping case or the inner wrappings will always be sealed when
tested weights are shipped from the Bureau.
(e) SUBMISSION OF WEIGHTS FOR TEST
A written request for the testing should be sent when the weights
are shipped. This should always indicate the class of weights sub-
mitted, and if two different tests are available in that class, the char-
acter of test desired. Sufficient information should also be given to
enable the Bureau to identify the package.
If weights have already been used as standards in exacting work, and
it is important to know what their corrections were at the close of
such work, this fact should be stated; otherwise, weights are carefully
cleaned before being tested.
Weights should be packed tightly. Sets in covered cases generally
need extra packing inside the case. The very small sheet-metal frac-
tional weights are especially likely to work out of place and be
damaged.
Address packages and correspondence, “National Bureau of
Standards, Washington, D. C.”
6. BALANCES
The methods of analysis employed in the sugar laboratory require
the use of a high-grade analytical balance for such operations as the
determination of ash, moisture, and specific rotation, as well as a
special sugar balance for the rapid weighing of sugars, molasses, and
sirup for the usual saccharimetric determinations.
In selecting an analytical balance, it is well to keep in mind several
essential points. The sensibility of the balance is influenced by (1)
distance between the center of gravity and the point of support, (2)
coincidence of the planes of the three surfaces on which the three
knife-edges bear, (3) length of the arms of the beam, and (4) reduction
of friction to a minimum by finely ground and polished knife-edges and
planes. In addition, the sensibility is affected by the weight of the
beam; in general, a balance with a light beam is more sensitive than
one with a heavy beam.
The Bates sugar balance, especially designed at the National Bureau
of Standards for saccharimetric work, has a number of improved
features. The customary bows supporting the pans have been re-
placed by single-arm hangers at the back, an arrangement which gives
free access to the pans and reduces to a minimum the danger of spilling
Sugar on the pans. The weighing scoop is adjusted to balance exactly
either of the pans, thereby avoiding the use of a counterpoise weight.
Polarimetry, Saccharimetry, and the Sugars 113
The errors introduced by evaporation or absorption of moisture
during weighing are greatly reduced by the rapidity of weighing with
this balance. The general design and construction of the balance is
such as to make it especially adapted for use in the tropics. It has a
capacity of 200 g, with a sensitivity of 1 mg, which may be increased
to 0.2 mg by raising the center of gravity weight on the pointer.
Figure 31.-Bales sugar balance.
7. REFERENCES
[1] NBS Circular C8, Testing of Thermometers (current edition).
[2] G. K. Burgess, BS J. Research 1, 635 (1928) RP22.
[3] E. F. Mueller and R. M. Wilhelm, Proc. Am. Soc. Testing Materials 38,
pt. 1 (1938). -

PART 2. RAW AND REFINED SUGARS AND SUGAR
PRODUCTS
VII. POLARIZATION OF RAW AND REFINED SUGARS
1. SAMPLING AND MIXING OF SAMPLES
The importance of a correct method of sampling raw sugar cannot
be overestimated. If this step is carelessly or erroneously carried out,
the most careful work on the part of the chemist is vitiated. The
details of the process of sampling should be arranged with two require-
ments kept in view: (1) The sample should be thoroughly representa-
tive of the package, and (2) after the sample is taken, it should undergo
no change until used for analysis.
In order to obtain a representative sample, the sampling instru-
ment, called the trier, should be plunged into the middle of the pack-
age and drawn out filled with sugar. If the trier has the correct length
and the sampling is skillfully done, all the layers of sugar in the pack-
age are represented in the sample. Great care should be exercised to
avoid taking a surface sample, since the variations caused by drying
or absorption of moisture have their maximum effect at the surface.
The dimensions of sugar triers are given in the regulations of the
United States Treasury Department relative to sampling of imported
sugars. These regulations are printed beginning on page 781 of this
Circular.
If the sugar is contained in barrels or other wooden packages, it
should be sampled by running the “long trier” or “barrel trier”
diagonally through the package from chime to chime. In case mo–
lasses has drained to the bottom of the package, especial care must be
taken to obtain the sample symmetrically.
In procuring samples from large shipments of sugar, it is advisable
to take samples from every package, to mix the large quantity of
material thoroughly, and to resample the mixture for analysis.
In order to prevent a change in the composition of the sample
taken, the total contents of each trier should be emptied into a tightly
covered receptacle and the trier left clean for the next sample, the
whole operation being completed within a few seconds. The subse-
quent mixing and resampling should be conducted in such manner as
to avoid unnecessary exposure to the atmosphere. These precautions
are necessary because of the great tendency of raw sugar to change its
moisture content when exposed to the air.
A large proportion of the impurities in raw sugar is in the form of
molasses clinging to the surfaces of the crystals, and the evaporation
or absorption of moisture may be very rapid. The action of an
absorbing material during mixing (such as the brown paper frequently
used) may affect the polarization very markedly by wiping the
molasses from the surfaces of the crystals. If samples are to be pre-
115
116 Circular of the National Bureau of Standards
served before analysis or for subsequent reference, they should be
placed in tightly sealed containers in order to avoid loss by evaporation.
Further details as to the correct procedure in sampling will be
found in the United States Treasury Customs Regulations, page 786.
2. DIRECT POLARIZATION
The determination most widely used in the analysis of sugar and
sugar products, both in chemical control during extraction and
refining and also in the adjustment of commercial transactions, is the
direct polarization. The term “direct polarization” is defined as the
reading on the saccharimeter of 26.000 g of the sample dissolved in
100 ml of solution at 20°C, with only such substances removed by
clarification as impede the passage of light. The value thus obtained
is the resultant optical rotation of all optically active substances
present in the solution and indicates the percentage of sucrose only
in cases where the other constituents have no effect on the rotation.
Distinguished from the direct polarization, is the Clerget, or double-
polarization, method, which indicates the true percentage of sucrose.
In sugars of high purity, the direct polarization and the sucrose by
the Clerget method give results that closely agree, but in low-grade
sugars and molasses the differences may become considerable.
The direct polarization is executed in a great variety of ways with
respect to the details of manipulation. The following method is the
one most conveniently used in commercial work, and if carefully per-
formed, the results are sufficiently uniform and reproducible for the
adjustment of sugar trade relations and for the control of sugar
manufacture in the sugar industry.
The sample is thoroughly mixed, all lumps being broken up, and
weighed very quickly in the weighing dish, great care being taken to
prevent moisture change during weighing, by hastening the process
as much as needed accuracy permits. (If the polariscope is read to
only 0.05% S, it is useless to weigh more closely than 0.015 g). By
means of a jet of distilled water, the sample is then washed into a
100-ml sugar flask and dissolved. This is readily accomplished after
a little practice. However, if difficulty is experienced, the trans-
ference to the flask may readily be made by use of a funnel, the stem
of which extends just into the body of the flask. The sugar is then
brought into solution by a few minutes shaking, a shaking machine
being convenient if large numbers of samples are to be handled. After
solution is complete, the clarifying agent is added. The method of
clarification depends on the nature and amount of impurities present.
The universal principle is to add the minimum quantity necessary to
clarify, whatever the agent added. In a large proportion of samples
the clarification consists in the addition of 0.5 to 2 ml of basic lead
acetate solution. The contents are mixed and the volume completed
to 100 ml, the neck of the flask being washed down. If foam appears
on the surface of the meniscus, rendering it impossible to adjust the
volume accurately, it may be dispersed by blowing upon it a small
quantity of alcohol or ether from an atomizer.
To obtain good definition while making up to volume, the bottom
of the meniscus should be made to appear dark by a reflection of the
finger or of a section of rubber tubing placed a few millimeters below
the mark on the neck of the flask. The meniscus, shaded in this way,
Polarimetry, Saccharimetry, and the Sugars 117
should be made tangential to the upper edge of the graduation mark.
It is essential that the temperature of the solution during the process
º the same as that of the saccharimeter, tubes, and quartz control
plates.
The solution is then shaken thoroughly and the entire contents of
the flask is poured on a filter in a stemless funnel. The first 25 ml of
the filtrate is rejected, since this portion is almost invariably made
turbid by the passage of a small amount of the lead precipitate through
the filter paper. In addition, the first portions passing through the
dry filter paper suffer a change in concentration, as shown by Hardin
and Zerban [1]. By rejecting the 25-ml portion, this absorption effect
is largely or wholly avoided. During the filtration it should be made
an invariable practice to cover the funnels with cover glasses to pre-
FIGURE 32-Bates saccharimeter and lamp.
vent evaporation of the solution. This important precaution is
frequently neglected. The contention that the evaporation is one of
the constant errors of this method is not valid. The evaporation is
not constant but depends on the accidental conditions of temperature,
relative humidity of the atmosphere, and the movement of air in the
room. Bates and Phelps [2] have made an exhaustive study of the
influence of atmospheric conditions in the testing of sugars. They
found for raw sugars, filtered once, that:
1. The increase in the polarization due to evaporation is negligible
in ordinary testing for all potential heads (P-PA) up to 22 mm,
and that it is therefore unnecessary to use any precautions to prevent
or to correct for evaporation for ordinary atmospheric conditions,
provided the duration of the filtration does not exceed 10 or 12
minutes.

118 Circular of the National Bureau of Standards
2. If the correction for the increase in polarization is desired, it may
be obtained from the following equation:
Q=0.00017 (P.-P.)T, (36)
where Q=increase in polarization in degrees sugar,
Ps=Saturation vapor pressure at the temperature of the solu-
tion,
Pa =Saturation vapor pressure at the temperature of the dew
point in the air,
T=time of filtration in minutes.
Q should be subtracted from the observed polarization to obtain
the true polarization.
3. Practically all increase in polarization, regardless of atmospheric
conditions, may be prevented by covering the funnel with a watch
glass.
When all or a part of the filtrate is returned to the filter, the con-
centration is increased, since this filtrate takes up the solution already
tº POUR EO 3F C K W H E N ALL THROUGH AW
A POURED BACK WHEN V2 THROUGH RAW SUGAR
G) NOT POURED BACK
OF E AND zºº.
MM HG
(P. -P) IN wº. OF HG
CHANGE IN POLARIZATION PER MINUTE=#-
FIGURE 33.-Curves showing the effect of evaporation on the polarization of raw
SugarS.
adhering to the filter paper and which has become concentrated by
evaporation after the level of the solution in the funnel has fallen.
Bates and Phelps show graphically in figure 33 the change in polariza-
tion per minute when normal solutions of raw sugars are poured back
after filtration.
Before filling the polariscope tube, it is rinsed two or three times
with the filtered solution. During the rinsing the filtration cylinder
should be given a rotary motion to stir its contents. This stirring
brings the solution to a uniform density, thereby permitting a sharp
focusing of the eyepiece of the saccharimeter. Care should be exer-
cised to avoid errors due to the physical condition of the tube.
The accepted reading of the saccharimeter scale should be the
average of at least three settings of the end point, and it is a great
advantage to use both eyes in making the observations.
Direct polarization by this method gives a value which is uni-
formly reproducible. It does not, however, represent the percentage

Polarimetry, Saccharimetry, and the Sugars 119
of sucrose in raw sugars, because it does not take into account other
optically active substances which are usually present.
3. CLARIFICATION
(a) GENERAL
All methods of clarification at present available have accompanying
disadvantages which necessitate great precautions in order to mini-
mize their effect.
The choice of a clarifying agent for polariscopic work depends
largely on the color of the sample to be tested. Agents in most fre-
quent use are alumina cream, basic lead acetate, and decolorizing
carbon. In less frequent use, but having some advantages in special
cases, are neutral lead acetate, basic lead nitrate, alum, sodium
hydrosulfite, and sodium hypochlorite.
(b) ALUMINA CREAM
Alumina cream is a suspension of aluminum hydroxide Al(OH)3 in
water. It is prepared by precipitation from alum or aluminum
sulfate solution by means of ammonia. The precipitate is washed
free of soluble salts or left unwashed, depending on the use to which
it is to be put.
In case the precipitate is to be washed, it is advisable to add the
ammonia in slight excess. The washing of the precipitate may be
conveniently carried out by suspending the mixture in parchment-
paper bags in a vessel of water, changing the water in the vessel fre-
Quently, or it may be washed in the usual way on a filter, provided
caution is used to prevent the precipitate from becoming dry. The
washing is continued until a portion of the wash water tested with
barium chloride shows only traces of dissolved sulfates. The washed
alumina cream may be used either as the sole clarifier for high-grade
samples, if its action is sufficiently effective, or it may be used in
conjunction with basic lead acetate. When used with lead, it in-
creases the clarifying action of the basic lead acetate and permits the
use of a smaller quantity than would otherwise be necessary. When
the washed alumina cream is used alone, the only error introduced is
caused by the volume of the precipitate of aluminum hydroxide. If
only a few milliliters is used, the volume of the dry solid is small, and
for all ordinary purposes, negligible.
If the alumina cream contains an excess of alum and other soluble
sulfates, its use is recommended by many as an aid to clarification by
basic lead acetate in the analysis of very impure products where a
large quantity of lead acetate is required. The alumina cream then
fulfills several purposes. It precipitates the excess of lead as lead
sulfate. It adds its own clarifying effect and tends to furnish a
slightly acid solution, which decomposes some of the compounds
formed by lead with some sugars, notably levulose.
Impure saccharine products usually contain large quantities of dis-
solved inorganic salts, so that the addition of a clarifier containing a
relatively small quantity of soluble salts is not seriously detrimental.
The method of preparation of the Association of Official Agricul-
tural Chemists [3] is as follows: Prepare a cold saturated solution of
alum in water. Add ammonium hydroxide with constant stirring
120 Circular of the National Bureau of Standards
until the solution is alkaline to litmus, allow the precipitate to settle,
and wash by decantation with water until the wash water gives only
a slight test for sulfates with barium chloride solution. Pour off the
excess of water and store the residual cream in a stoppered bottle.
(c) BASIC LEAD ACETATE
(1) PREPARATION.—Basic lead acetate is the clarifying agent most
extensively used. It is formed by the chemical combination of normal
y
a’
4
/º \ º bO 4H /
/ V \ \) 3RbWC.
. –7– - 7 7 7
| O 2O 4 O 5O 6O 7O
% P b(C2 H3 O2) 2
30
FIGURE 34.—Isothermal equilibrium between lead acetate, lead oride, and water at
25° C.
lead acetate, Pb(C2H5O2)2 with litharge, PbO. Jackson [4] in a
study of the equilibrium in the system lead acetate, lead oxide, and
water, has shown that four compounds capable of existing in the
solid phase are neutral lead acetate, Pb(C2H5O2)3.3H2O.; tetra-lead-
monoacy-hea:acetate, 3Pb (C2H5O2), PbO.3H2O; tri-lead-dioacy-diacetate,
Pb(C.H.O.),2PbO.4H2O; and lead hydrozide, Pb(OH)2. The basic
lead acetate of commerce is a mixture of the two basic acetates,
3Pb (C2H5O)2.PbO and Pb (C2H5O2)2.2PbO. The reagent known as
Horne's dry lead has been found to be quite uniform in composition.
It consists of a mixture corresponding to 4 parts of 3Pb(C2H3O3)2PbO
and 3 parts Pb(C2H5O2)2.2PbO. At this Bureau it has been found








Polarimetry, Saccharimetry, and the Sugars 121
advisable to use this product for preparing the clarifying solution,
as well as for dry lead clarification, by the Horne method [5].
The laboratory method of preparing the solution prescribed by the
Association of Official Agricultural Chemists [3] is as follows:
Boil 430 g of neutral lead acetate, 130 g of litharge 0 and 1 liter of water for 30
minutes. Allow the mixture to cool and settle, and then dilute the supernatant
liquid to a specific gravity of 1.25 with recently boiled distilled water. Solid
basic lead acetate may be substituted for the normal salt and litharge in the
preparation of the solution.
In 1909 The International Commission for Uniform Methods of
Sugar Analysis, adopted the solution of basic lead acetate of the
German Pharmacopoeia, which is prepared by boiling 3 parts normal
lead acetate, 1 part lead oxide, and 10 parts of water. Various other
proportions of lead acetate and lead oxide for the preparation of the
reagent are given in various handbooks.
With the exception of the dry basic lead acetate prepared by a few
firms, the samples occurring in commerce and also samples prepared
in the laboratory, even by official methods, vary in composition
within wide limits. Basic acetates having the highest proportion of .
PbO have the greatest clarifying power, but they also combine to the
greatest extent the errors accompanying clarification with this reagent.
The constitution of basic acetate may be determined chemically by
a double analysis of the sample.
(2) ANALYSIs.-Weigh out 10 g of the solid or take a known
volume of the solution containing approximately this quantity of the
solid substance, and dissolve in water in a 500-ml flask. In general,
this will give a milky solution because of the partial hydrolysis of the
lead salt. In order to avoid the possibility of the subsequent forma-
tion of basic lead sulfate, it is advisable to add a measured volume
of normal acetic acid until a clear solution is obtained. Then add the
equivalent of 60 ml of normal sulfuric acid, fill to a volume of 501.3 ml,
close the flask, shake thoroughly, and allow the precipitate to settle.
The extra 1.3 ml is to compensate for the volume of the precipitated
lead sulfate, and is added from a burette after filling the flask to the
500-ml mark.
After the precipitate has settled, determine the excess of sulfuric
acid by adding a slight excess of barium chloride to 100 ml of the
clear solution. Filter the precipitate, ignite, and weigh as barium
sulfate. The calculation of the total lead present computed as lead
oxide is as follows:
_T ºnn a lif v for for — wt. BaSO, - 4 TD
iſm H2SO4}x normality factor 1/2 mol. wt. BaSO, 1/2 mol. wt. PbO
* ,,,,,,,, wt. BaSO4
OI 5575ml H2SO, X factor 0.1167 |
To ascertain the quantity of lead present in the form of Pb(C2H5O2),
and that in the form of PbO, add to another 100-ml aliquot portion a
few drops of phenolphthalein and titrate with a standard caustic
alkali solution, taking the necessary precautions to free the solution
of carbonic acid. The calculation of PbO is as follows: 5 (total ml of
normal acid added—ml of normal alkali) 1/2 mol. wt PbO.
6 Directions for the preparation of activated litharge are given under (i)(1) p. 237 this Circular.
122 Circular of the National Bureau of Standards
The total normal acid is the sum of the acetic and sulfuric acids.
This computation gives the weight of lead present as lead oxide.
If this is subtracted from the total lead oxide, the remainder is the
lead oxide present in the form of neutral acetate, and this weight
multiplied by the factor 1.4574 reduces it to the weight of neutral
acetate.
Basic lead acetate has the great advantage of efficiency, but it has
also many disadvantages which require the exercise of great caution
in its use. In general, the minimum quantity which is necessary to
clarify the solution should be used. This quantity is gaged with
requisite accuracy by experienced workers. The needed quantities
for particular cases cannot be stated, but the following approximate
numbers are given as examples: For Java, Peruvian and Cuban
“first” sugars, from 0.5 to 2 ml of the lead solution; molasses sugars,
2 to 4 ml; Philippine III, 3 to 6 ml. Molasses usually requires 6 to
12 ml. Many analysts follow the lead treatment by adding a little
alumina cream. The washed alumina cream is used for high-grade
samples, the cream with soluble sulfates for low-grade samples.
(3) CoRRECTION FOR WOLUME OF PRECIPITATE.—The basic lead
acetate owes its clarifying action to its ability to precipitate the
suspended albuminoids along with other organic impurities. Since the
total volume of 100 ml is occupied by the solution and precipitate, the
solution alone occupies somewhat less than the volume indicated and is
thus correspondingly concentrated. The error in the polarization
thus caused has occasioned considerable discussion, and a number of
methods have been devised either to correct or to avoid it.
Method of Sachs. [6].-This is practically a direct measurement
of the volume of the precipitate. It is described in the Spencer-
Meade Handbook [7] as follows: Clarify 100 ml of the juice or the
dissolved normal weight with the subacetate as usual. Wash the
precipitate by decantation, first with cold water and finally with hot
water until all of the sucrose is removed. Transfer the precipitate
to a 100-ml flask and add one-half the normal weight of cane sugar
(of known polarization), dissolve the sugar and dilute the solution
to 100 ml; mix, filter, and polarize, using a 400-mm observation tube.
The volume of the precipitate is (100P' – 100P)/P', in which P
is the polarization of the sugar taken, and P' the polarization of the
sugar in the presence of the precipitate.
Method of Scheibler. [8].—To 100 ml of the sugar solution 10 ml
of lead solution is added and the saccharimetric reading taken. A
second solution is prepared by mixing the same volumes of the
saccharine liquid and lead solution, which is then diluted to 200 ml
and polarized.
The Scheibler method may be expressed by the following equations:
r= 100R/(100—A), where r is polariscopic reading, R the true reading
if the solution were continued in 100 ml, and A the volume of the
precipitate. Similarly, r1= 100R/(200–A). Combining the two equa-
tions and eliminating A, we obtain R=rri/(r—ri). A further simpli-
fication is due to C. A. Browne, who deduces the expression R=4r1–r.
Method of Horne.—The following method gives a more direct
determination of this volume and is free from the difficulty of determin-
ing Small differences between large numbers. A solution of the raw
Sugar is prepared and precipitated in the usual manner. The pre-
cipitate is allowed to settle and is washed by decantation, all the
Polarimetry, Saccharimetry, and the Sugars 123
washings being poured through a weighed Gooch crucible. As little
of the precipitate as possible is transferred to the filter. When the
washing is completed, the precipitate is transferred to a weighed
picnometer, which is filled to the mark and weighed. The difference
between the first and final weighings gives the total weight of the lead
precipitate.
The density of the precipitate is found in the following way:
Let c=weight of precipitate transferred in decanting,
A=weight of water in picnometer when filled,
B=weight of water and precipitate in picnometer,
C=weight of precipitate in picnometer found by difference be-
tween second and third weighing of Gooch crucible,
C+ W= total weight of precipitate, and
Density=C/A— (B–C).
The total volume of the precipitate is then its total weight divided
by its density, thus
volume=WID=*MA-(B-C).
If care is taken to avoid any considerable loss of precipitate during
the decantation, the determination may be shortened by neglecting
the small quantity of precipitate lost in this way. The washed
precipitate may be transferred directly to the picnometer, which is
filled and weighed. The picnometer is then emptied directly upon a
weighed Gooch filter. The volume of the precipitate is then the weight
of water displaced in the picnometer by the precipitate, or A– (B-C).
If the weight of the precipitate lost in the decantation does not ex-
ceed a few percent, the shorter method is satisfactory.
Horne dry-lead method.—A method intended to avoid rather than
correct for the effect of the volume of the lead precipitate has been
proposed by Horne [5]. Dissolve the sample in water and make up
to 100 ml before adding the clarifer. Add a minimum quantity of dry
basic lead acetate until sufficient clarification is obtained. Or, as in
careful work with a lead solution, add the solid in successive small
amounts until precipitation is almost complete. It is evident that it
is necessary to stop short of complete precipitation because an excess
of the solid, which does not produce a corresponding precipitate, serves
to swell the volume of solution and a corresponding error is intro-
duced. Horne has been able to show that by this method the volume
of the solution is very approximately that indicated.
(4) EFFECT ON SUCROSE,--It is often erroneously stated that basic
lead acetate has no effect on the rotation of sucrose. The experiments
of Bates and Blake [9] show that errors in rotation caused by excessive
amounts of basic lead acetate solution are of equal importance to the
other errors in saccharimetry. These authors have found, figure 35,
that an excess of 9% ml causes a diminution of polarization of 0.10° S;
1 ml, 0.12° S.; 2 ml, 0.11° S.; 3 ml, 0.09° S. The rotation reaches a
minimum value when an excess of 1 ml is present. It returns to its
initial value when 6 ml in excess has been added and continues to
increase linearly with the amount of lead solution added. If as much as
50 ml is present, the rotationis then increased by a whole degree Wentzke.
This source of error is avoided if the minimum quantity of lead solution
necessary to clarify is added.
124 Circular of the National Bureau of Standards
(5) EFFECT ON LEvu Los E.-By the action of basic lead acetate on
levulose, the direct polarization may be considerably disturbed. This
effect may occur from two causes. A soluble combination of lead
and levulose may be formed which has a lower specific rotation than
levulose or the lead-levulose compound may be actually precipitated
from solution. The result in either case is an increase in dextrorotation
or a higher polarization. Prinsen Geerligs has shown that basic acetate
of lead precipitates levulose when the same solution contains salts
which are capable of producing insoluble compounds with lead.
0.9
0.8
0.7
0.6
0,5
0.3
0.2
*} 0.1
99.90°
- 0,1
4.
ML OF BASIC LEAD ACETATE
FIGURE 35.-Influence of lead acetate on normal sugar solution.
The combinations between lead and levulose are very easily broken
up by a slight acidification. Acetic acid is sufficiently effective, but
many other acids have been used for this purpose. Sulfur dioxide,
tannic acid, and, as is frequently claimed, a solution of alum is acid
enough to decompose this rather loose combination. In any case,
only a slight excess of acid should be present.
(d) BASIC LEAD NITRATE (HERLES SOLUTION)
Herles solution [10] is prepared by dissolving 100 g of solid NaOH
in 2 liters of water, and a second solution is prepared by dissolving 1 kg
of neutral lead nitrate in 2 liters of water. Upon mixing equal
volumes of the two solutions, basic lead nitrate is precipitated, the
reaction being expressed by the equation
2Pb(NO3)2+2NaOH = Pb(NO3)2.Pb(OH)2+2NaNO3.
The precipitate is washed free of soluble impurities and mixed with
water to a cream for use in clarification. The clarification may also
be performed by forming the basic lead nitrate in the solution to be
polarized. This is done by first adding a measured quantity of the
above lead nitrate solution, 1 to 10 ml, according to the darkness of
the sample, and then, after mixing, adding an exactly equal quantity

Polarimetry, Saccharimetry, and the Sugars 125
of the alkaline solution. An excess of alkali must be avoided. The
mixture is then shaken and made to volume. The latter procedure
gives the better clarification but introduces a considerable quantity of
soluble salts, which may affect the polarization. The defects of the
basic nitrate are, in general, those of the basic acetate. The volume
of the precipitate is even greater because of the bulk of the solid
clarifier. The precipitation of reducing sugar is even more marked
than in the case of the basic acetate.
(e) HYPOCHLORITE (ZAMERON METHOD)
The hypochlorite solution is prepared by grinding 625 g of dry
bleaching powder in a mortar with 1 liter of water. The mass is
Squeezed out in a sack and the extract filtered through paper. The
filtered solution, about 700 to 800 ml of about 18° Baumé, is preserved
in a stoppered dark-glass bottle in darkness. To perform the clarifica-
tion, a few milliliters of the hypochlorite solution is added to the sugar
solution and then a few milliliters of neutral lead acetate solution.
The reagent usually causes a slight rise in temperature so that the
solution should be readjusted to the temperature of the polariscope
before making to volume. This method of clarification is very
effective, and if no great excess of the reagent is employed, the reducing
sugars are unaffected. The volume of the precipitate, which is
increased because of the presence of insoluble lead chloride, is the
main fault of this method.
(f) HYDROSULFITE
Sodium hydrosulfite is prepared by the reaction of zinc, sodium
bisulfite, and sulfuric acid according to the formula
2NaBHSOs + Zn + H2SO, F ZnS2O4 –H Na2SO4 + 2H2O.
The zinc hydrosulfite is changed to the sodium compound by the
reaction
ZnS2O, + Na2CO3 - Na2S2O, + ZnCO3.
The sodium hydrosulfite is salted out from solution by means of
sodium chloride and dehydrated by warming with strong alcohol.
The compound is then dried in a vacuum at 50° to 60° C. This
substance is produced commercially under the names of Blankit and
Redo. It is frequently used in sugar manufacture for bleaching
massecuites and, in dissolved form, as a wash for whitening sugar
in centrifugal machines. To prepare a solution for polarization, a
quantity of alumina cream is added and then a few crystals of hydro-
sulfite, 0.1 to 1 g, according to the color of the solution. The solution
is made up to volume, shaken thoroughly, and filtered. As the
clarified solutions occasionally redarken, they should be polarized
immediately. The clarifying action, according to Weisberg [11], is
due to free sulfurous acid and nascent hydrogen. The reduction by
the latter leaves compounds which may be reoxidized and cause a
redarkening of the solution.
Another hydrosulfite derivative (sodium sulfoxylate-formaldehyde)
known as Rongalite accomplishes a permanent clarification but it is
slower and less effective than Blankit.
323414°–42——10
126 Circular of the National Bureau of Standards
The defects of hydrosulfite as clarifiers are, in addition to the
frequent redarkening, their effect on reducing sugars, the possible
separation of finely divided sulfur, and their ineffectiveness in dis-
charging the color of caramel bodies. Bryan [12] states that the
rotation of dextrose is lowered by hydrosulfites and finds evidence of
the formation of a laevo oxysulfonate. No immediate effect is
observable upon sucrose or fructose, but sucrose is apparently inverted
by a prolonged action. These clarifiers have not come into general
use in analytical work, but nevertheless they are unique in that they
produce no volume error.
(g) BONE CHAR
In cases where neither alumina cream nor lead subacetate is capable
of producing a clear solution, recourse may be had to bone black. Bone
black, for analytical purposes, may be prepared by treating the
granular material used in sugar refining with a slight excess of hydro-
chloric or nitric acid until all of the mineral matter is dissolved. The
treated char is washed with boiling water, dried at 120°, and finely
powdered and bottled. The more completely the material is freed
from mineral matter, the more effective is its action for analytical
purposes. Bone black probably owes its clarifying action to the very
large surface which is caused by its porosity.
The most serious error accompanying clarification with bone char
is caused by its tendency to absorb sugar and thus give abnormally
low readings. For this reason, most official methods of clarification
exclude bone black as an agent. It is difficult to make a correction
for the amount of sugar absorbed, because it varies with the composi-
tion and concentration of the sample and the condition of the bone char.
In order to avoid the error arising from the absorption of sugar, the
absorption coefficient may be determined under the approximate
conditions of the analysis or the solution may be made up to volume
and filtered through a column of bone black, the first third of the
filtrate being rejected.
4. REFERENCES
[1] G. H. Hardin and F. W. Zerban, Louisiana Planter 73, 388 (1924).
[2] F. J. Bates and F. P. Phelps, Bul. BS 10, 537 (1914) S221.
[3] Official and Tentative Methods of Analysis of the Association of Official
Agricultural Chemists, 5th ed., p. 490 (1940).
[4] R. F. Jackson, Bul. BS 11, 331 (1914) S232.
[5] W. D. Horne, J. Am. Chem. Soc. 26, 186 (1904).
[6] F. Sachs, Z. Wer. deut. Zucker-Ind. 30, 229 (1880).
[7] G. L. Spencer and G. P. Meade, A Handbook for Cane-Sugar Manufacturers
and Their Chemists, 7th ed., p. 224 (1929).
[8] C. Scheibler, Z. Ver. deut. Zucker-Ind. 25, 1054 (1875).
[9] F. J. Bates and J. C. Blake, Bul. BS 3, 105 (1907) S52.
O] F. gº Z. Zuckerind. Böhmen 13, 559 (1888); 14, 343 (1889); 21, 189
1896).
1] J. Weisberg, Centr Zuckerind. 15, 975 (1906).
2] A. H. Bryan, Bul. Bur. Chem. No. 116.
[1
[1
[1
VIII. CLERGET METHOD
1. INTRODUCTION
The direct polariscopic reading of a sugar solution is the resultant
rotation of all optically active substances present, and is conse-
Polarimetry, Saccharimetry, and the Sugars 127
quently a correct measure of the sucrose only when the other sub-
stances present have no effective rotatory power. If other optically
active substances are present, the direct polarization must be supple-
mented by a second observation in which the rotations of these sub-
stances are kept constant while that of sucrose is subjected to a change
which can be measured and is known to be an exact function of the
quantity of sucrose. This change is brought about by the hydrolysis
of sucrose to invert sugar. The change of rotation of the normal solu-
tion of pure sucrose is known as the Clerget divisor. The divisor is
not a constant but its numerical value is influenced by concentration,
temperature, and impurities. The hydrolysis or inversion can for
analytical purposes be effected by either the enzyme, invertase, or by
hydrochloric acid.
In its simplest form applicable to the ideal case, where nothing but
the rotation of sucrose is altered, the Clerget formula is
(P–P')
CEacLö(F20)”
Percentage of S=
in which P and P' are the direct and invert polarizations, respectively,
of the normal solution; C, the basic value of the Clerget divisor at
20°C; ac, the change in the value of the divisor with concentration of
substance; and b, its change for each degree rise in temperature.
The Clerget formula is frequently applied in the above form without
assurance that the fundamental condition is fulfilled, namely, that the
rotations of all substances except sucrose remain unaltered in the two
polarizations. In general, it is true that for samples containing high
percentages of sucrose and small quantities of invert sugar the method
yields reliable results and that for low-grade products it yields results
which are sometimes sufficiently accurate for the purposes at hand. .
Of the two commonly employed hydrolytic agents, invertase is
the superior because of its highly selective action on the sucrose group
and because it is without effect on the rotations of other substances
occurring as impurities in sugar samples. Its disadvantages are its
relatively high cost, the considerable labor required for its preparation,
the uncertainty that the preparation has retained its activity, and,
except under certain conditions, the long time required for the com-
pletion of the hydrolysis. :
Hydrochloric acid, on the other hand, involves negligible expense
and is capable of completing the hydrolysis in any desired period of
time by merely regulating the temperature of reaction. However,
it is not selective but hydrolyzes any glycosidic group. Moreover, it
influences the rotatory power of invert sugar and many other impuri-
ties occurring in natural products.
2. ACID METHODS
(a) BASIC VALUES OF THE CLERGET DIVISOR
In devising the method, Clerget [1] in 1849 took 50 ml of a normal
sucrose solution in a 50- to 55-ml flask, added 5 ml of “pure and fum-
ing” hydrochloric acid, and after mixing, placed the flask in a water
bath so regulated that 10 minutes were required to raise the tempera-
ture of the solution to 68°C. Upon attaining this temperature the
flask was removed, cooled rapidly to 20°C, and the solution polarized.
128 Circular of the National Bureau of Standards
The invert reading was multiplied by 11/10. The percentage of
sucrose was calculated by the formula
__100D
S f
144–5
j
in which D is the algebraic difference between the two corrected polari-
zations and t is the centigrade temperature.
Browne [2] modified the Clerget method by allowing the solution to
invert overnight at room temperature and making it to a volume of 55
ml at the completion of the inversion. It was pointed out that as the
result of three factors a contraction in volume of about one-third of a
milliliter occurred in the original method. The diminution in volume
is caused, first, by the contraction which all sucrose solutions undergo
during inversion and which for 13 g of sucrose in 55 ml is about 0.25
ml; second, the elevation of temperature caused by dilution of 5 ml of
concentrated hydrochloric acid; and third, by the evaporation of water
during the inversion. The advantage claimed by the author is that
the invert solution, being but slightly diluted, can be observed with
practically the same precision as the solution for direct polarization
and with no great multiplication of errors, as is the case in methods in
which the invert solution is more highly diluted. This advantage is
lost, however, if the invert solution in the alternative methods is ob-
served in a 400-mm column.
Browne found the percentage of sucrose to be expressed by the
formula *
S= f 100D f y
144.9–3–0.01(144.9–3–D)
in which the parenthetical term multiplied by 0.01 in the denominator
is the correction of the divisor for concentration of sugar. If the
concentration of sucrose is diminished from 26 to 25 g, the parentheti-
cal term becomes roughly 5.19 and the concentration coefficient 0.052
for 1 g of sucrose. This value is considerably lower than the prevailing
value 0.0676, and quite at variance with the revised value, 0.0794, of
Jackson and McDonald discussed in a later paragraph.
Jackson and Gillis [3] showed that under the conditions prescribed
by Browne inversion is complete in 8 minutes at 60° C.
In 1888 Herzfeld [4] devised the modification of the Clerget method
which has remained in use to the present day. He observed the direct
polarization in the usual manner, employing the normal weight of
sucrose. He then took the half-normal weight (13 g) in 75 ml of
solution, added 5 ml of hydrochloric acid (38 percent or 1.188 specific
gravity), and warmed the solution to 67° to 70° C in from 2 to 3 min-
utes. The solution having attained the prescribed temperature, he
kept it as near 69° C as possible for 5 minutes, when it was quickly
cooled, made to a volume of 100 ml at 20°C, and polarized at the same
temperature. Being that of a half-normal solution, the reading was
ºpied by 2. Under these conditions he found the Clerget formula
to be
s=="—
T 142.66–0.5;
Polarimetry, Saccharimetry, and the Sugars 129
The basic value of the Clerget divisor in the above formula, 142.66,
is defined as the algebraic difference between the rotation of the
normal pure sucrose solution at 20° C (i. e., +100) and twice the
rotation of 13 g of inverted sucrose in 100 ml at 20°C, corrected to
0°C by the term +0.5t. The actually measured value, free from the
jºinty of the value of the temperature coefficient, is 132.66 at
20° C.
The basic value of the divisor has been the subject of numerous
investigations with different results. Herzfeld, in his original publica-
tion, adopted the value 132.66 at 20°C, but apparently the actual
measurement was made by Dammiller [5]. Later investigators have
invariably obtained higher values: Walker [6], 132.78; Tolman [7],
132.88; and Steuerwald [8], 133.05. Jackson and Gillis computed that
by the Herzfeld procedure the destruction of invert sugar caused a
lowering of the rotation by 0.15 to 0.20° S, which, deducted from
their recalculated value, 133.18, left a resultant rotation of —33.03 to
—32.98.
In 1920 Jackson and Gillis [3] published the results of a careful
series of measurements in which they inverted sucrose solutions at 60°
C instead of 70° C in order to avoid the destruction of invert sugar.
They made their measurements at a somewhat higher concentration
than the half-normal solution in order to utilize such standard quartz
plates as were available, thus eliminating the errors of graduation
of the saccharimeter scale. They were consequently obliged to
correct their observed rotations for the higher concentration of sugar,
using for this purpose the then prevailing value 0.0676 per g departure
from 13 g of sucrose per 100 ml. Recent experiments have shown
that this coefficient is considerably too low and that a recalculation of
the Jackson and Gillis value for the rotation of the half-normal weight
is necessary. Thus their originally announced value, –33.25, now
becomes —33.18 at 20° C.
Subsequent to the publication of the Jackson and Gillis measure-
ments, but previous to the appearance of the German translation of
the same article [9], Herzfeld published a posthumous work of Schre-
feld [10], whose experiments were made in 1910 to 1912. Schrefeld
dissolved the half-normal weight of sucrose in 75 ml of water and
added 5 ml of concentrated hydrochloric acid (sp gr 1.19). Inserting a
thermometer in the sugar solution, he immersed the flask in a water
bath having a temperature of 70° C, and agitated it until in 2% to
2% minutes the solution had reached a temperature of 67° C. From
this moment he allowed it to remain in the bath for exactly 5 minutes,
during which time the temperature gradually rose to 69.5° C. The
flask was removed and cooled rapidly to 20.0° C and the solution
made up to 100 ml. Polarization measurements were made at 20° C.
As a mean of seven concordant polarizations, Schrefeld found the
rotation of the half-normal solution multiplied by 2 to be –33.00.
This value has not been officially adopted by the International Com-
mission for Uniform Methods of Sugar Analysis but has been widely
used and has been verified by Browne. Zerban and coworkers under
similar conditions found —32.97; Spengler, Zablinsky, and Wolf [11],
–33.02; and Jackson and McDonald, -32.99. Thus the basic
value, 133.00 at 20° C, for inversion under the Schrefeld conditions
must be considered a well-established constant. It has been adopted
officially by the Association of Official Agricultural Chemists.
130 Circular of the National Bureau of Standards
Jackson and McDonald have experimentally corroborated the
recalculated value –33.18 of Jackson and Gillis and have extended
their measurements to include values obtained after inversion at
several other temperatures. The Arrhenius formula, 37, evaluated
by Jackson and Gillis, and discussed further on page 133 permits a
calculation of the velocity constant of inversion at any desired tem-
perature in the presence of 0.7925 N hydrochloric acid. With the
aid of this equation, Jackson and McDonald [15] calculated the time
required for 99.99-percent hydrolysis at 49° and 35°C, respectively,
and measured the rotation of the half-normal solution. They found
the value –33.25 for both temperatures.
Many analysts advocate inversion at room temperature as a safe
means of avoiding decomposition of invert sugar. Formula 37 en-
ables us to calculate the velocities of inversion and times required for
99.99-percent inversion at the temperatures which may be expected
in uncontrolled laboratories. These periods of time vary considerably
with small changes of temperature, as is shown in table 10. While the
velocities of many reactions double themselves with a rise of 10 de-
grees in temperature, the velocity of inversion of cane sugar increases
more than fourfold between 20° and 30°C. Thus room-temperature
inversion is safe only if such variations of temperature as inevitably
occur are known to the analyst and are considered in calculating the
time required for complete hydrolysis. It appears from table 10
that 24 hours is insufficient for hydrolysis at 20°C, that 16 or 17 hours
for overnight inversion at 30° C is excessive, and that serious decom-
position of invert sugar can result. Evidently room-temperature
inversion must be carried out with considerable discretion.
TABLE 10.-Time required for inversion of sucrose at room temperature by 0.7925
- N hydrochloric acid


Time for Time for Time for
Temper- | Velocity 1 99.99- Temper- | Velocity 1 99.99- Temper- Velocity 1 99.99-
ature | constant percent ature constant percent ature constant percent
IIl VerSIOIl IIl VerS10Il IITVerS1OI).
oC Hours oC Hours oC Hours
18 0.001590 41.9 24 || 0, 003941 16.9 30 0.009421 7.08
20 . 002161 30, 8 26 | . 005290 12. 6 32 | . 012502 5.33
22 | . 002924 22.8 28 . 007073 9.4
1 Common logarithms and minutes.
For room-temperature inversion the value of the negative constit-
uent of the Clerget divisor adopted by the Association of Official
Agricultural Chemists is –33.20. Jackson and McDonald [15]
have measured this constant with care by inverting the half-normal
weight of sucrose in a thermostat which maintained a constant tem-
perature within a few hundredths of a degree. The times of inversion
were calculated by formula 37 for temperatures varying from 20° to
25° C. The mean value found for the rotation of the half-normal
solution was –33.29.
In recapitulation, table 11 shows the values of twice the rotation of
the inverted half-normal solution. All of these measurements except
the first one at 70° C were made with care to avoid the destruction of
invert sugar after the completion of the inversion. Jackson and
Gillis showed that when sucrose is inverted by the Herzfeld method
Polarimetry, Saccharimetry, and the Sugars 131
in a bath at 70° C decomposition of invert sugar ensues as a result
of too drastic conditions. Jackson and McDonald [15] have carried
out the inversion in a 70° bath but have shortened the final period
of heating from the prescribed 5 minutes to 3, 2, and 1 minute,
respectively. In these measurements the value —33.00 for 5 minutes
rose to a maximum of —33.08 at the 2-minute period. With this
value included, all of the values in table 11 except the first represent
twice the rotation of the inverted half-normal solution, the destruc-
tion of invert Sugar after the completion of the inversion being avoid-
ed. It is evident that the rotation is definitely a function of temper-
ature and that invert sugar is attacked by acid during the course
of the inversion. Conceivably furanoid fructose, which has a trans-
itory existence, is attacked by the acid, and increasingly so as the
temperature rises.
TABLE 11.-Variation of twice the rotation of the half-normal invert-sugar solution
with varied conditions of inversion


Tempera- * Tempera-
...ture of Time Rotation ...ture of Time Rotation
inversion inversion
oC sº oS oC oS
67 to 69 5 min-------------------- —33.00 49 38 min------------------- —33. 25
67 to 69 || 2 min-------------------- —33.08 35 | 205 min------------------ —33. 25
60 9.5 min------------------ —33, 18 25 | 17.2 hr------------------- —33. 29
The data in table 11 illustrate the importance of specifying the
time and temperature of inversion for the standard values of the
divisor and of adhering closely to the specifications in carrying out
the analysis. For practical purposes there are three temperatures
which require consideration. Room temperature is quite suitable
if the precautions stated above are observed. For more rapid work
the inversion can be effected in a bath regulated at either 60° or 70°
C. At 70° there is a destruction of about 1 percent of invert sugar,
and the analysis is incorrect unless such destruction occurs. It is
quite possible to reproduce the value, –33.00, with relatively pure
sugars, but the question arises whether in crude substances, which
are heavily charged with inorganic salts of weak acids, the acid retains
its activity. If by buffer action the activity of the acid is diminished,
it is possible that the 1 percent of invert sugar is not destroyed and
an error in the analysis would result, since the basic value of the divisor
to be used at 70° requires that such decomposition occur. The same
statements are of course true of the 60° inversion, but here only one-
third of 1 percent of invert sugar must be destroyed. Moreover,
such destruction occurs unavoidably during the process of inversion
and not both during and after the inversion, as is the case at 70°.
These considerations make it appear that the 60° inversion advo-
cated by Jackson and Gillis is preferable to that at 70°, but further
experiments are required before a final decision can be made. It is
true that at 60° many final molasses are not completely inverted in
the specified period of time. Such samples would require either a
prolonged time of inversion at 60° or an elevation of the temperature
to 70°, and the value of the divisor under these altered condition
requires determination. .
132 Circular of the National Bureau of Standards
Until much additional work is done it appears advisable to employ
alternatively three inversion temperatures, namely 70°, 60°, and
that of the laboratory, and to use for each temperature the proper
basic value of the divisor. Detailed methods are given on page 152.
Walker [12] has devised a method of inversion which has the advan-
tage of requiring a minimum of attention. In this method 75 ml of
the solution used for the direct polarization is transferred to a 100-ml
flask and heated in a water bath to 65° C. The flask is removed
from the bath, and to the solution is added 10 ml of HCl (dº 1.1029).
The solution is allowed to cool spontaneously in the air for 15 minutes
or as much longer as may be convenient, made to volume, and
polarized in the usual manner. The advantage claimed in addition
to its convenience is that the maximum temperature coincides with
the minimum quantity of invert sugar, and thus the destruction of
levulose is diminished. Walker did not determine the basic value
of the divisor, but Jackson and Gillis in a limited number of experi-
ments found it in agreement with the value obtained by inversion at
60° C. It is, therefore, tentatively assigned a value of 133.18.
Low-grade products which were clarified by basic lead acetate
suffered decomposition of reducing sugar during the period of heating
as a result of the excess basic lead in the filtrate. Walker therefore
advised, in these instances, the addition of 1 or 2 ml of acid to bring
the solution to neutrality or slight acidity.
(b) VELOCITY OF INVERSION OF SUCROSE
The hydrolysis of sucrose, when catalyzed in dilute aqueous solu-
tion by acids, follows the unimolecular reaction formula
*m-. | jº Ro–R.
k=; In}=#.
in which Ro and R. are, respectively, the initial and final rotations,
and R, is the rotation at the time t. Under any one set of conditions,
k is constant during the course of the reaction but varies somewhat
with the concentration of sugar and directly with the activity of the
acid. An inspection of the chemical equation shows that two molecu-
lar species are involved in the hydrolysis, namely sugar and water.
The amount of water which disappears is, however, in dilute solution
quite insignificant in comparison with the amount of water present
in the solution, and it is for the reason that the concentration of water
remains practically constant that the unimolecular formula applies.
That the reaction is of second order becomes evident if reaction
velocities of different concentrations of sugar are compared. Thus
Jackson and Gillis found the velocity constant 0.002161 for 19.5 g
in 100 ml of solution at 20°C, while Jackson and McDonald found,
under the same conditions of temperature and volume concentration
of acid, a constant of 0.003355 for 83.3 g in 100 ml. This large differ-
ence of 50 percent is probably due to increased activity of the hydro-
chloric acid as well as to the increased concentration of sucrose.
Jackson and Gillis [3] measured the velocities of hydrolysis of sucrose
in the presence of 0.01, 0.10, and 0.7925 N hydrochloric acid for a
concentration of 13 g of sucrose in 80 ml of solution, over a wide
range of temperatures.
Polarimetry, Saccharimetry, and the Sugars
133
Arrhenius [13] proposed the hypothesis that some molecules in a
reacting system contained sufficient energy to react, while some were
inactive, and, if the system contained a constant amount of energy
there would be an equilibrium between active and inactive molecules.
Thus
__[active molecules] .
inactive molecules
The displacement of the constant with temperature follows the van't
Hoff equation
d log k Q
di TT.I.T.’
in which Q is the energy of activation. If () is constant over a wide
range of temperatures, this equation can be integrated to the form
Q *#)
k+,+k+le” Tº T'i 5
in which T represents absolute temperature, and R is the gas constant.
Jackson and Gillis applied this formula to their velocity-constant
measurements with satisfactory agreement.
The data are computed to a usable form in table 12. These data
are reproduced to serve as a guide for general use. They are applicable
to a concentration of 13 g of sucrose in 80 ml and will deviate slightly
for different concentrations of sugar.
(37)
TABLE 12.-Time required at various temperatures for 99.99-percent inversion
$n the presence of 0.01, 0.1, and 0.7925 N hydrochloric acid as catalyzer

0.01 N. HC] 0.1 N H Cl 0.7925 N H Cl
Tempera- Time for e º
ture Velocity 99.99-per- Velocity { Time ſo Velocity Time for
constant cºver. constant | *Pºnt constant | *Pºent
b. sion - *...* -- . . . 1I] VérSIOIn II]. VerS101]
o C. - Hours
20 (). 00001899 3, 511 0.0002032 || 328 hr. (). 002161 30.8 hr.
25 , 00003984 1, 673 . 0004264 156 hr. . 004569 14. 6 hr.
30 , 00008148 818 . 0008.737 76 hr. . ()09427 7. 1 hr.
35 . 0001629 409 . ()01747 38. 2 hr. , 0.1900 3.5 hr.
40 . 0003186 209 . 003453 19. 3 hr. . ()3785 106 min.
50 . 001145 58 . 01230 5. 4 hr. . 1365 29.3 min
60 . 0.03806 17. 5 . 04151 1. 6 hr. . 4606 8.7 min
70 . 01182 5. 6 . 1273 31.4 min. 1.447 2.76 min
80 . 03303 2. 02 . 3542 11.3 min. -------- ----------
90 . 08982 0.74 --------- " ---------- -------- ----------
(c) INFLUENCE OF CONCENTRATION OF SUGAR ON THE CLERGET DIVISOR
The specific rotations of both dextrose and levulose vary with the
concentration of sugar, and that of invert sugar likewise varies with
concentration, as is shown by the Gubbe [14] equation
[o]}=–19.447–0.06068p––0.000221p”,
in which p is the percentage of invert sugar. Thus the basic values of
the Clerget divisor discussed above are valid only for a concentration
of 13 g of inverted sucrose.
Herzfeld applied to the basic value of the divisor the correction
0.0676 (m—13), in which m is the weight of inverted sucrose in 100 ml
134 Circular of the National Bureau of Standards
of the solution taken for the invert polarization. This value of the
coefficient has remained in general use to the present day. Steuerwald
found a slightly higher value, 0.0717. Herles found 0.067 and Sazavsky
0.0677.
Jackson and McDonald [15] have recently measured this coefficient
by observing the polarization of a series of solutions prepared by
dilution of an invert-sugar solution over a wide range of concentrations.
By this procedure assurance was had that all variables such as those
arising from the inversion reaction itself were eliminated, the only
variable being that caused by dilution. Two series of measurements
were made. In one series each solution contained 10 ml of 6.34 N
hydrochloric acid in 100 ml, the condition which prevails in the acid
Clerget method; in the other series no substance other than dextrose
and levulose was present, the condition of the enzymotic method of
analysis. The results are given in table 13. The respective coeffi-
cients are shown in the following formulas:
(0.634 NHCl) P’ = — (32.265–1–0.07935S)
(Pure water solution) P’ = — (30.994+0.08241S)
in which P’ is the rotation calculated to 26 g of sucrose, and S is the
weight of sucrose in 100 ml of solution. The relation proved to be
linear between 2 and 26 g of sucrose.
TABLE 13.-Measurement of the concentration coefficient of invert sugar
10 ml of Synthetic invert sugar, P’ = —(30.994+
6.34 NHCl P’ = —(32.265+0.07935° S) 0.08241° S)
Weight of f —P', calcu- Weight of p, — P', calcu-
SUICTOSé —P', found lated SUICrOSé P', found Hated
g o S o S g o S o S
26. 000 34.33 34.33 25. 6001 33. 11 33. 10
23. 6201 34. 13 34. 14 23. 2542 32.91 32.91
20. 7796 33.93 33.91 20. 4571 32.66 32.68
18. 1639 33.68 33. 70 17.8814 32.47 32.47
15. 5841 33. 51 33. 50 15. 3376 32. 25 32. 26
12.98.91 33. 29 33. 29 12. 7940 32. 08 32.05
10. 6115 33. 13 33. 11 10. 1919 31.85 32.84
7. 7942 32.84 33. 89 7. 6688 31.61 31.63
5. 1782 32.71 33.68 || --------- --------- ---------

(d) EFFECT OF VARYING TEMPERATURE ON THE CLERGET DIVISOR
The specific rotation of levulose varies considerably with the
temperature of observation, while that of dextrose is very nearly
independent of temperature. The specific rotation of invert sugar,
and consequently the negative constituent of the Clerget divisor, are
therefore functions of temperature. Clerget found that the divisor
diminished 0.5° S for each degree increase of temperature above 20°
C, and applied the correction—0.5t to his value 144.0, in which t is
the centigrade temperature and 144.0 is the divisor extrapolated to
0° C. This does not imply that the value 144.0 is actually valid at
0°; it rather means that for relatively small deviations from 20°C,
the correction is valid. If, as Zerban suggests, the basic value is
defined as the reading at 20°C, the temperature correction becomes
–0.5 (t–20). This value of the temperature correction has remained
in general use to the present day. Tuchschmidt [16] in 1870 found
Polarimetry, Saccharimetry, and the Sugars 135
the value to be —0.50578t, but it is questionable whether the instru-
ments available at that early date were capable of the precision required
for so accurate a measure of the coefficient.
Zerban calculated from Vosburgh's observations that the coefficient
for the half-normal (German) weight of sucrose would be —0.478 and
for the quarter-normal weight, —0.466. Gillet [17] reported a value
of -0.49 for the half-normal solution. Zerban states that the value
-0.50 for final cane molasses at quarter-normal concentrations is
considerably too high.
It is evident that considerable uncertainty attaches to the value of
the temperature coefficient and that new careful measurements are
urgently required.
The foregoing coefficients apply solely to the polarization of the
inverted solution. Sucrose also has a definite, although small, tem-
perature coefficient. The normal solution diminishes 0.03% S per
degree increase of temperature, so that the negative temperature
coefficients given above are to be increased to a higher negative value
by 0.03° S when applied to the whole Clerget divisor. Pending further
accurate measurements and general agreement, it appears necessary
to use 0.53 for the temperature coefficient except in special instances
where a different value is known to apply accurately.
In applying the Clerget divisor and its temperature coefficient to
actual analyses, it is assumed that the solutions are made to volume
and polarized at the same temperature, the saccharimeter wedges
likewise being at this temperature. Zerban recommends that these
readings be made at exactly 20° C in view of the uncertainty of the
temperature coefficients. Evidently this difficult requirement can be
met only by laboratories that have complete temperature control.
It is urgent therefore that the temperature coefficients not only
of the pure sugars, but also of the commonly occurring crude mixtures,
be determined.
It frequently occurs that the two polarizations differ slightly from
each other in the temperature of observation. In such a case it is
preferable to calculate the results from the temperature of the invert
polarization alone and, whenever possible, to correct the direct polari-
zation and the quartz wedges to this temperature. If the temperature
of the wedges differs from that of the solution under observation, the
reading can be corrected to the temperature of either solution by
applying the temperature coefficient of quartz, namely 0.000148 per
degree temperature per degree sugar. Since the effect of the coeffi-
cient is to lower the reading of the scale with increase of temperature,
the apparent polarization is lower than it should be. Thus if a solution
polarizes 100° S and the wedges are 1 degree centigrade higher than the
solution, the reading must be increased by 0.015. Obviously these
corrections need be made only for high polarizations and considerable
differences in temperature.
If the solution for direct polarization is free from invert sugar, as is
the case with beet products, and if made to volume and polarized at a
temperature different from that of the invert polarization, it can be
corrected to the temperature of the latter by
P,-P,’--0.0003 P(t’—t),
in which t and tº are the temperatures of the invert and direct polari-
zations, respectively.
136 Circular of the National Bureau of Standards
If, finally, the solutions for direct and invert polarizations were
made to volume at the same temperature but polarized at different
temperatures, the direct polarization (if free from invert sugar) can
be corrected to the temperature of the invert polarization by
P,-P, +0.00061 P(t’—t),
in which the coefficient includes the changes arising from the change
of rotary power of sucrose and the expansion of the solution.
(e) EFFECT OF HYDROCHLORIC ACID
Many dissolved substances affect the rotation of invert sugar, the
greater number elevating it to a higher negative rotation but some
altering it in a positive direction. Hydrochloric acid is most common-
ly used as the inverting agent, and its effect has been shown to increase
the negative rotation to a higher negative value. Jackson and Gillis
studied this effect quantitatively and found that the negative rotation
was enhanced as the concentration of acid was increased, the relation
being precisely linear up to 1.3 N hydrochloric acid and approximately
so up to 2.5 N. They confined their measurements to a single concen-
tration of invert sugar, namely that formed by the inversion of 13 g
of sucrose in 100 ml of solution. In their formula, R and Ro repre-
sent the rotation at 20°C of 13 g of inverted sucrose multiplied by 2,
m the grams of hydrochloric acid, and N the normality of the acidified
solution.
If we select for a stock hydrochloric acid one having a normality
of 6.34 (d.” 1.1029),
R=Ro-0.1250, (39)
in which v is the number of milliliters of 6.34 N acid in 100 ml of the
solution polarized.
It is evident from these equations that the concentration of acid
should be carefully regulated. Instead of the 5 ml of concentrated
acid previously used, Jackson and Gillis recommended dilution of
strong acid to 6.34 N or d,” 1.1029. This constitutes a 1:1 dilution
if the original concentrated acid contained exactly 38.8 percent of
hydrochloric acid. As this is seldom the case, it is preferable to adjust
the diluted acid to the concentration specified. This specification has
been adopted by the Association of Official Agricultural Chemists
[18]. Ten milliliters are used for inversion.
If in eq 39 the correction term which, evaluated for 10 ml of 6.34
N hydrochloric acid, becomes –1.25°, is applied, and if the experi-
mentally determined values of R given in table 14 are then substituted,
the equations can be solved for Ro, the rotation of invert sugar in the
absence of acid. If no decomposition of invert sugar during the in-
version reaction occurred, Ro would equal the rotation of pure invert
sugar, or in other words, the Clerget divisor by the invertase method.
For the acid inversion at 70° C, Ro becomes — 31.75; for 60° C,
–31.93; for room temperature, — 32.03; and for 4°C, -32.08. The
accepted value for invert sugar by invertase inversion is –32.10.
Evidently in all methods of acid inversion, decomposition of invert
sugar occurs, but to a diminishing extent as the temperature of
inversion is decreased.
Polarimetry, Saccharimetry, and the Sugars 137
(f) EFFECT OF VARIOUS REAGENTS ON THE ROTATION OF INVERT SUGAR
An effect on the rotation of invert sugar similar to that of hydro-
chloric acid is produced by neutral salts. It is thus not because of its
acidity that hydrochloric acid enhances the negative rotation of invert
sugar, but rather because it, like many salts listed below, is a dissolved
substance which, conceivably on account of its high degree of solva-
tion, produces an effect similar to an increase in concentration.
Jackson and Gillis [3] studied systematically the effect of various
reagents on the rotation of invert sugar. They derived the formulas
given in table 14, in which R is twice the rotation in saccharimeter
degrees of the half-normal solution, and m the weight in grams per
100 ml of the substance (anhydrous) whose effect is measured. Fur-
ther but less detailed measurements are given in table 15.
TABLE 14.—Effect of salts on the rotation of invert sugar a
J ºn 1 + Molecular Equivalent
Salt R depression depression
HCl- > -- - - - - - - - - - - - - R = —32.10–0. 5407 m_ _ _ _ _ _ _ _ _ _ _ - - - - - - - - - - - - - - - - - - - - - - - 19. 71 19. 71
NaCl. . . . . . . . . ------ R=–32. 10–0.540 m - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ... 31. 56 31. 56
NH4C1. - - - - - - - - - - - - - R= —32. 10–0.563 m - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 30. 12 30. 12
CaCl2. -- - - - - - - - - - - - - R= —32. 10–0.710 m - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 78. 80 39.90
K2C2O4- - - - - - - - - - - - - R=–32. 10–0.510 m - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 84, 77 42. 39
H3PO4- - - - - - - - - - - - - - R=–32.10--0.0776 m - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - | . . . . . . . . . . . . . . -
HC2H3O2- - - - - - - - - - - R=–32.10+0.0823 m - - - - - - - - - - - - - - - - - - . . . . . . . . . . -- - - - - | . . . . . . . . . . . . . . . . . . . . . -->
• In their original article, Jackson and Gillis used the value —32.00 for invert Sugar in the absence of re-
agents. However, they determined merely the slope of the curves upon addition of reagents. The sub-
Stitution of the correct value, –32.10, does not affect their measurement of the slope.
It will be recognized that the list of salts is far from comprehensive,
but the data show clearly that relatively large variations in the
rotatory power of invert sugar can arise as a result of the admixture of
salts and furthermore that the anion produces unpredictable effects.
Under the column headed “molecular depression” is given the
depression caused by 1 mole of dissolved substance, and under “equiv-
alent depression” that caused by the salt calculated to valence 1. A
very rough similarity in the equivalent depression caused by the
sodium, potassium, and ammonium salts seems to occur, 1 molecular
equivalent depressing the rotation by 25° to 40° S. Further reference
will be made to this relation under a discussion of Saillard's modifica-
tion of the Clerget method.
Attention should be directed to the well-known effect of basic lead
acetate on the rotation of invert sugar. This is probably due to a
chemical combination of the basic lead constituent with levulose and
illustrates the necessity of acidifying the direct polarization of a crude
substance which contains invert sugar and which has been defecated
TABLE 15.—Influence of various reagents on the rotation of invert sugar

Change in Change in Correspond-
rotation per | Equivalent rotation ing equiva-
Reagent gram in depression Reagent per gram lent depres-
100 ml in 100 ml Sion
oS oS oS oS
Pb(C2H3O2)2.JPbO . . . . . . . . +1. 43 |------------ KC]------------------- —0.486 38. 6
Pb(C2H3O2)2- - - - - - - - - - - - - - –0. 020 | - - - - - - - - - - - - Na2HPO412H2O. —. 161 28.8
NH4NO3--...-------------- —. 399 31.9 || NaC2H3O2- - - - - - - - - - - - —. 314 25.8
138 Circular of the National Bureau of Standards
with basic lead. Acetic acid, and probably many other weak organic
acids, change the rotation of invert sugar in a positive direction.
(g) ROTATION OF SUGAR MIXTURES AND THE EVALUATION OF m
It has been shown above that the rotatory power of pure invert
sugar increases in a negative sense with increase in concentration, and
that for the analysis of pure sucrose the Clerget divisor must be
increased by the quantity 0.0794 (m—13), in which m is the number of
grams of sucrose taken in the sample for the invert polarization. The
question now arises as to what the value of m is if the original sample
contains invert sugar, organic nonsugars, or inorganic salts in admix-
ture with sucrose. In general, sugar-cane products contain all four
of these constituents, while beet products usually contain all except
invert sugar.
Consider first the analysis of a mixture of sucrose and invert sugar.
The essential condition of the Clerget method is that the rotation
of the invert sugar in the direct polarization be the same as in the
invert polarization. Jackson and Gillis (3, 9) showed that a given
quantity of invert sugar in the presence of sucrose had a slightly
lower negative rotation than it would have if all of the sucrose were
inverted. However, since its rotation approached constancy more
closely if the concentration of total sugar were unaltered than if the
relatively large effects of dilution were introduced, they recommended
that both direct and invert polarizations have the same concentration
of the sample. This expedient was admitted by the authors to be a
first approximation “since the problem of the rotation of mixtures
was too large a one for a complete solution at that time.” If now the
plausible assumption is made that the rotatory power of sucrose is
unaltered by admixture with invert sugar, its change of rotation
upon hydrolysis would be from the positive rotation of sucrose itself
to the negative rotation of invert sugar at the concentration of total
invert sugar, which is the sum of the invert sugar formed by hydrolysis
and the invert sugar originally present. Since the variations in the
Clerget divisor are caused only by the variations of the specific rota-
tion of invert sugar with concentration, the quantity m should
represent the grams of total sugar in 100 ml of solution rather than
the grams of sucrose.”
Vosburgh [19] in a more general study measured the rotations of
mixtures of sucrose, dextrose, and levulose and stated his results in
an article which has been widely quoted and very frequently mis-
quoted. Vosburgh summarized his conclusions as follows:
1. The specific rotations of glucose and fructose when mixed in equal
proportions (invert sugar) are those which the sugars would have if
each were present alone at a concentration equal to the total invert-
sugar concentration.
2. In mixtures of glucose and sucrose the specific rotations of the
two are those which the sugars would have if each were present alone
at a concentration equal to the total sugar concentration.
3. The relationship is only approximate for mixtures of fructose
and sucrose, in which case the rotation is a little smaller (or larger
numerically if negative) than that calculated upon its assumption.
i. This is a reversal of the recommendation of Jackson and Gillis, who substituted for m the grams of sucrose
3.10116.
Polarimetry, Saccharimetry, and the Sugars 139
4. The polariscopic determination of the percentage of sucrose
replaced by invert sugar gives slightly high results.
It should be noted that the statement in conclusion 1, which was
confined to pure invert sugar and was not even applied to all dextrose-
levulose mixtures, has frequently in subsequent literature been extended
to apply not only to all sugar mixtures but to all sugar-nonsugar
mixtures. Conclusion 4, which concerns the Clerget analysis spe-
cifically, implies that conclusion 1 does not apply exactly to sucrose-
invert sugar mixtures, the deviation amounting to about 0.4 percent,
an error quite appreciable in Clerget analysis. This conclusion is in
harmony with the previously described experiment of Jackson and
Gillis, although the precision of analysis by the invertase method
and by the compensation methods described in later paragraphs is
closer than 0.4 percent. It should be recognized that the expedients
suggested in this paragraph are recommended as approximations and
are subject to alteration as knowledge of the rotations of sugar mix-
tures advances.
Zerban [20] in an extensive study of the analyses of complex sugar
mixtures showed that satisfactory agreement of calculated and de-
termined values of sucrose was obtained if “in these calculations the
divisor corresponding to the total sugar concentration, and not that
for the sucrose concentration, is used.” In other words, m represents
the number of grams of total sugars taken for inversion and made up
to 100 ml after inversion.
In a further study Zerban prepared samples simulating cane mo-
lasses by combining accurately known quantities of its constituents,
and here he found it necessary to assign to m the total weight of dry
substance taken for inversion.
(h) INFLUENCE OF REAGENTS ON THE ROTATION OF SUCROSE
Sugar sirups of commercial importance frequently contain appreci-
able quantities of inorganic salts. Cane and beet molasses are es-
sentially sirups in which, by removal of sugar, the salts have accumu-
lated to such an extent that no further crystallization of sugar is
possible. The presence of salts causes an alteration of the rotatory
power of sucrose and, therefore, not only is the direct polarization of
plant juices rendered uncertain, but both the direct and invert polari-
zations of the Clerget method are affected and the analytical results
are made uncertain unless the change in the direct is the same as in
the invert polarization.
In general, dissolved inorganic salts diminish the rotatory power of
sucrose. For a few salts, Jackson and Gillis measured this depression
and found it linear with respect to concentrations of salt ranging
between 0 and about 4 g in 100 ml. They established the relations
shown in table 16.
TABLE 16.—Effect of salts on the rotation of sucrose
Molecular Equivalent
Salt R depression depression
NaCl------------------- R=100–0.265 m - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 15. 5 15. 5
NH4C1- - - - - - - - - - - - - - - - - R= 100–0.169 m -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9. 0 9. 0
CaCl2------------------- R= 100—0.339 m -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 37.6 18.8
K2C2O4----------------- R= 100–0.234 m_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -- - - - - - - - - - - - - - - - 38.9 19. 4
140 Circular of the National Bureau of Standards
In the early literature [21] efforts were made to find some regularity
between the depression and the molecular weight of the salt, and
indeed the “molecular depression,” that is, the depression caused by
1 g multiplied by the molecular weight, approached constancy for a
few closely related salts, such as the chlorides of barium, strontium,
and calcium. But molecular depression failed of constancy if applied
more generally. Evidently in the relations listed above no constant
molecular depression can be observed.
The depression caused by a given quantity of salt is, in dilute
solution, a constant percentage of the rotation of pure sucrose quite
regardless of the concentration of the latter. Thus Jackson and Gillis
[22] showed by their own measurements and by calculation of the
careful measurements of Browne [23] that 3.392 g of ammonium
chloride produced the same relative depression on the rotation of
sucrose, even when the concentration of the latter was varied between
5 and 52 g in 100 ml. When all rotations were calculated to 26 g of
sucrose, the depressions were found to be the constant quantity
0.56° S. Similarly, 2.315 g of sodium chloride in 100 ml of a sucrose
solution caused depressions of rotation which, when calculated to 26 g
of sucrose, amounted to 0.62° S, quite regardless of the concentration
of sugar.
Brown [24] extended these studies to very low concentrations of
sugar and various salts, expressing this relation by the formula
Percentage of sugar=P+KPM,
in which P is the polarization, M the weight in grams of the salt
present in 100 ml of the solution polarized, and K a constant which is
characteristic for each salt. The following values of K were found
mainly by measurement in very dilute solution, and with inevitable
multiplication of error:
Salt R
NaCl----------- - - - - - - - - - - - - 0. 00246
K2SO4--- - - - - - - - - - -- - - - - - - - - - . 001.99
Na2SO4.10H2O . . . . . . . . . . . 00205
Na2HPO4.12H2O – . . . . . . . . . . . 00305
Brown thus agreed with Jackson and Gillis that the depressive effect
of salt was the same relative fraction of the total polarization regardless
of concentration. Hence the values of K can be determined at high
concentrations where the errors are small and applied to the low
concentrations of thin juice and other dilute sirups.
(i) METHODS OF COMPENSATION
The direct application of the Clerget method in unmodified form to
low-grade cane and beet products frequently leads to the introduction
of analytical errors which are due to the effects of impurities in such
samples. Cane products usually contain, in addition to sucrose,
invert sugar which in the case of molasses may amount to 30 percent
or more of the total sugar. It is necessary that the rotation of this
invert sugar remain unaltered in both the direct and invert polariza-
tions. Mention has already been made of the necessity of observing
both polarizations in the same concentration of substance in order to
avoid the change in rotation caused by dilution. An additional source
of error is introduced in the acid methods of inversion as a result of the
Polarimetry, Saccharametry, and the Sugars 141
fact that the invert sugar which is present as an impurity has its
rotation increased negatively in the invert reading in the presence of
the hydrochloric acid. Browne (25) has shown by applying the simple
acid Clerget method to pure synthetic mixtures of invert sugar and
sucrose that gross inaccuracies can be caused by the changed rotation
of the added invert sugar in the two polarizations.
TABLE 17.-Errors of analysis of sucrose caused by invert sugar
Sucrose Sucrose
Invert Sugar In Vert Sugar ---
Found Taken Found Taken
g/100 ml Percent Percent g/100 ml Percent Percent
1. 10 96. 18 96.15 8. 21 38.99 38.46
2. 74 77. 10 76. 92 9.86 19.82 19. 23
5. 48 58. 14 57. 69 || - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Jackson and Gillis sought to avoid this source of error by adding to
the solution for direct polarization a neutral salt in such quantity
that its effect on the invert sugar just equalled that of hydrochloric
acid. The effects of added reagents on the rotation of invert sugar
have been described on page 137. It was shown that 10 ml of 6.34
N hydrochloric acid in 100 ml increased negatively the rotation of the
negative constituent of the divisor by 1.25° S. From the list of neutral
salts it can be computed that 2.312 g of sodium chloride in 100 ml
produces the same change of rotation. If, therefore, this weight of
salt is added to the solution for direct polarization, the invert sugar
present as an impurity will have the same rotatory power in both
polarizations. But the addition of salt has now diminished the rota-
tory power of the normal sucrose solution from 100° to 99.38° S.
The total change in rotation of sucrose is then from 99.38 to −33.18,
and the Clerget divisor becomes 132.56 at 20° C. This is the basis
of the Jackson and Gillis method IV described on page 155.
Nitrogenous substances consisting mainly of amino acids and their
internally compensated salts occur in both beet and cane molasses.
Many of these are optically active but possess one rotatory power in
acid solution and quite a different one in neutral or alkaline solution.
In order to compensate for this source of error Saillard (26) proposed
that the invert solution be neutralized with sodium or potassium
hydroxide. The method was elaborated in greater detail by Jackson
and Gillis, who proposed that ammonia be used for neutralization
because it had less destructive action on invert sugar than the more
caustic alkalies. The neutralization of 10 ml of 6.34 N hydrochloric
acid with ammonia produces 3.392 g of ammonium chloride; this
causes an increased value of the negative constituent of the Clerget
divisor, making it –33.84. This method of compensation was de-
signed for beet products which were free from invert sugar. The
basic value of the Clerget divisor becomes 133.84 for inversion at 60°C,
or 133.94 for room-temperature inversion. This was designated Jack-
son and Gillis method III.
Many samples of sugar products contain both invert sugar and
amino acids. Jackson and Gillis in method II sought to compensate
for the altered rotation of these substances by neutralizing the solution
323414°–42—11
142 Circular of the National Bureau of Standards
for invert polarization with ammonia and adding 3.392 g of ammon-
ium chloride to the solution for direct polarization. This diminishes
the rotation of sucrose from 100° to 99.43° S. The basic value of the
divisor according to this method is 133.27.
Method III has had such limited use that it will not be described
in the present Circular. While it is capable of eliminating the errors
which otherwise would be introduced by the altered rotations of
aminoacids, it still serves no useful purpose, because quite invariably
products which contain aminoacids also contain raffinose. Such
products, therefore, contain three unknown quantities and cannot be
analyzed accurately by processes which yield but two equations. The
method, however, has been utilized by Osborn and Zisch, whose
procedure is described in a later paragraph (p. 160).
Saillard [27] has emphasized the fact that molasses contains sodium
and potassium salts of organic and inorganic acids which diminish the
rotation of sucrose and increase the levorotation of invert sugar.
These two effects are incompletely compensated, the effect on invert
sugar being the greater. His proposed remedy is to determine the ash
content of each sample, and in a control test to determine the Clerget
divisor by adding to pure sucrose and to the invert-sugar solution
sodium or potassium chloride in amount equivalent to the ash in the
sample. Thus for beet molasses no less than four polarizations and
an ash analysis are required for a single Clerget test. Saillard's
proposal has not been put into extensive practice, primarily because
of the prohibitive labor involved. Moreover, the procedure rests on
a questionable basis, because the assumption is made that sodium
and potassium chlorides produce the same effects as the alkali salts of
all other acids, regardless of the nature of the anion. In other words,
Saillard unwittingly assumes the constancy of “molecular depression,”
which numerous previous experiments had shown was lacking. Never-
theless, it is quite possible that Saillard's procedure diminishes the
error caused by alkali salts in the sample, and it would be desirable to
investigate the effects upon the rotations of sucrose and invert sugar
of the particular alkali salts which are known to occur in molasses.
The special determination of the divisor for each test recommended
by Saillard appears to be an unnecessary complication, for we have
complete equations for the effects of sodium chloride upon sucrose and
invert sugar and of potassium chloride upon invert sugar. If the
procedure should prove of value, these equations could be solved for
any desired concentration of salt.
Zerban and Gamble (28] have studied the question by preparing and
analyzing known solutions of sucrose mixed with low-purity products
of high ash content and observed no noticeable effect on the Clerget
divisor, provided the divisor was based on the dry-substance concen-
tration. (See conclusion 10, p. 145).
The ingenious suggestion has been made by R. J. Brown, who
pointed out that the data of Jackson and Gillis showed that the effect
of a given quantity of salt was approximately twice as great on invert
sugar as on sucrose, and that in the absence of invert sugar in the
sample, if the concentration of salt in the invert polarization is half as
great as in the direct, the effect is completely compensated in the two
polarizations. It is then merely necessary to use the normal weight
for the direct polarization and the half-normal weight for the invert
polarization.
Polarimetry, Saccharimetry, and the Sugars 143
(j) CREYDT RAFFINOSE FORMULA
Creydt [29] has shown that, in the absence of other optically active
substances, sucrose and raffinose can be estimated by the Clerget
method. This estimation depends upon the fact that for the solution
of two unknown quantities two equations are sufficient. One of these
equations states that the direct polarization is the sum of the rotations
of the two constituents, and the other states that the invert polariza-
tion is the sum of the rotations of the products of hydrolysis.
Assume that the analysis is conducted at 20°C and that the normal
weight of the sample is contained in 100 ml. Let the sample contain
S percent of sucrose and R percent of anhydrous raffinose. Since the
specific rotation of anhydrous raffinose is + 123.2, while that of sucrose
is +66.5, the raffinose in the mixture will have 1.852 times as great a
rotatory power as an equal weight of sucrose. The direct polarization
then will be
P=S+ 1.852R. (40)
Let the invert solution contain 13 g of sample and the reading in the
presence of 0.634 N hydrochloric acid be multiplied by 2. Raffinose,
upon inversion, yields a mixture of levulose and melibiose, the resul-
tant rotation of which was, according to early measurements, 0.5124
times the rotation of the unhydrolyzed raffinose. Browne and Gamble
[30], revising this ratio, found the value 0.514. Osborn and Zisch [31]
found a slightly lower value, but nevertheless accepted and used the
value 0.514. The structure of the Creydt formula is such that small
variations in the raffinose inversion factor have little effect upon the
calculated sucrose or raffinose percentages. The invert polarization
of the raffinose constituent is then 0.514 X 1.852R=0.952R. The
invert reading of inverted sucrose varies slightly with the method of
inversion. If we accept the Schrefeld method, the basic value of the
negative constituent of the Clerget divisor is —33.00, while if we
employ the Jackson and Gillis method of inversion at 60°C, the divisor
is —33.18; if the method of overnight room-temperature inversion is
employed, the value becomes —33.29. It is therefore necessary to
derive three slightly different Creydt formulas.
If we assume that the basic value of the divisor is 133.00 at 20°C,
P’ = –0.3300S-H-0.952R, (41)
whence, upon elimination of R from eq 40 and 41
_0.5140P–P’
S= T0.84.40 T at 20°C, (42)
and
P–S -
R=1.353 (43)
The derivation is quite similar when the other values of the divisor
are used, the resulting formulas differing only in the values of the
denominator, as appears in columns b and c in table 77, p. 563. These
formulas are valid only at 20° C and for 13 g of dry substance taken
for the invert polarization.
144 Circular of the National Bureau of Standards
The direct and invert polarizations of sucrose vary with tempera-
ture,
P=S(1–0.0003 (t–20))=S(1,006–0.0003t)
P’ =S(–0.3300+0.005 (t–20))=S(–0.4300+0.005t).
Browne and Gamble [30] have shown that the change of direct
polarization of raffinose with temperature is very nearly the same as
that of sucrose. The direct polarization of a mixture of sucrose and
raffinose is then
P=S(1,006–0.0003t) + 1.852R(1.006–0.0003t). (44)
The accepted value of the temperature correction of the negative
constituent of the Clerget divisor is +0.5t. Browne and Gamble have
measured the change of polarization of invert raffinose with tempera-
ture, and have found that a solution of raffinose having a direct
polarization of +1.00 would have an invert polarization of +0.478+
0.0018t. The invert polarization of a mixture of sucrose and raffinose
would then be
P’ = S(–0.4300+0.005t) + 1.852R(0.478-1-0.0018t). (45)
This equation is strictly valid only for 13 g of dry substance taken
for inversion, and a further correction of –0.000794 (m—13) must be
applied to the parenthetical coefficient of S.
Simultaneous solution of eq. 44 and 45 and the introduction of the
concentration correction yield
P(0.478-1-0.0018t) — P' (1.006–0.0003t)
*-(IOO6·Hoodosijñāoší0.003;iiodoúðið. II3)] (*)
P–S
R= T.S.52" (47)
Equation 46 is cumbersome to handle in ordinary analytical work.
In order to facilitate its application, the respective coefficients have
been computed and assembled in table 77, p. 563. Equation 46 may
be expressed in the form
* a P-b P’
Tbo-T0.000794 (m-13)'
S (48)
and the coefficients a, b, c, and be may be calculated for various
temperatures. The term “c” is valid only for 13 g of dry substance,
and for any variation of concentration the correction +0.000794
(m—13) as determined by Jackson and McDonald [15], or +0.000676
as used by Herzfeld, must be applied to the denominator.
The Creydt formula, as is shown by its derivation, is valid only in the
absence of other optically active substances than sucrose and raffinose.
Beet products contain, in addition to these sugars, optically active
nitrogenous substances, the presence of which vitiates the formula
with respect to precision. It is, however, extensively used and the
errors of analysis are tolerated. For strict accuracy the double-
enzyme method or, in certain localities, the double-acid method of
Osborn and Zisch [31] is required.
Polarimetry, Saccharimetry, and the Sugars 145
(k) WORK OF ZERBAN AND COLLABORATORS
Zerban and Gamble [32] have summarized the work of The New
York Sugar Trade Laboratory in a series of articles [33] and have
applied the principles to a study of the analysis of crude products.
The solutions previously analyzed contained known amounts of su-
Crose in mixture with invert sugar; reversion products of invert sugar;
the amino compounds asparagine and aspartic acid, which are the
Pºpal substances of this nature found in cane products [34]; and
SaltS.
The four inversion methods employed were: (a) The official inver-
tase method of the Association of Official Agricultural Chemists [18]
p. 470, (b) Jackson and Gillis method II [3, p. 184], (c) Jackson and
Gillis method IV (3, p. 187]; and (d) Schrefeld’s modification of the
Herzfeld plain acid method [10]. The inversions were carried out
mostly at room temperature, but in some of the work higher tempera-
tures were employed; 55° C in method (a), 60°C in methods (b) and
(c), and 67° to 69.5°C in method (d).
f i. results of these investigations may be summarized briefly as
OJIOWS.
1. The solution used for the direct polarization must have the same
dry-substance concentration as the solution used for inversion.
2. The Clerget divisor must be based on the dry-substance concen-
º and not on the sucrose concentration or on the invert reading
8,1OIle.
3. It is preferable whenever possible to carry out the inversions at
room temperature, because at high temperatures slight variations in
the time used may have an appreciable effect on such reactions as the
destruction of invert sugar in the presence of strong acid, on the
hydrolysis of inversion products, and on the interaction between in-
vert Sugar and amino compounds.
4. The invertase method is the only one of the four methods com-
pared which may be depended upon to give reliable sucrose results.
5. The sucrose result by Jackson and Gillis method II is increased
by reversion products hydrolyzed under the conditions of the analysis.
6. The sucrose result by Jackson and Gillis method IV is increased
by the hydrolysis of the reversion products in the same way as in
method II, but aspartic acid or asparagine lowers the sucrose result
considerably.
7. Accordingly, the difference between the sucrose result by Jackson
and Gillis method II and that by the invertase method gives a relative
measure of the reversion products hydrolyzed by hydrochloric acid
under the conditions of the analysis.
8. The difference between the sucrose result by Jackson and Gillis
method II and that by method IV gives a relative measure of the
amino compounds present.
9. The plain acid method may give any kind of result, high, low,
or correct within the limits of error, depending on the relative propor-
tions of levulose, reversion products, and amino compounds present.
10. In the case of mixtures of known amounts of sucrose with a
practically sucrose-free low-purity product, containing 13.74 percent
of ash on the basis of dry substance, the salts, as such, had no notice-
able effect on the Clerget divisor for any of the four methods investi-
gated, provided the divisor was based on the dry-substance concen-
tration.
146
Circular of the National Bureau of Standards
The four methods which had been applied to artificial mixtures
containing known quantities of sucrose were then used in the analysis
of various blackstraps and refinery sirups. The inversions were car-
ried out at a temperature of 26° to 30° C, and the polariscopic
readings were made at the standard temperature of 20° C. The
results, which are averages of many analyses calculated in accordance
with rules 1 and 2 given above, are shown in table 18.
TABLE 18.-Comparsion of sucrose found by four Clerget methods
Jackson *
Number Jackson ge º 'º s Plain
of Material Invertase land Gillis *...* acid
. Samples method II IV method
Percent | Percent | Percent | Percent
8 || Filtered sirups------------------------------------- 34.86 35.43 35. 14 35. 25
6 | Refinery blackstraps------------------------------- 33. 34 34.46 33.85 34. 11
9 || Raw-Sugar blackstraps----------------------------- 33.65 |---------- 34. 12 34. 27
Without exception, Jackson and Gillis method II gave higher
figures than either the invertase method or Jackson and Gillis method
IV. This shows that all the samples contained reversion products
as well as amino compounds. The quantity of the reversion pro-
ducts, expressed as sucrose, in the refinery blackstraps varies from
0.64 to 1.32 percent, averaging 1.12 percent; and the quantity of
amino compounds from 0.40 to 0.89 percent, averaging 0.61 percent.
In the filtered sirups there are found 0.10 to 1.03 percent, averaging
0.57 percent, of reversion products, and 0.11 to 0.66 percent, averag-
ing 0.29 percent, of amino compounds, all again expressed as equiva-
lent sucrose. Expressed as asparagine or aspartic acid, the content
of amino compounds in blackstraps and refinery sirups is, according
to data given by Ambler [35] and by Browne [36], very much higher,
in the neighborhood of 2 to 2.5 percent.
Leaving out Jackson and Gillis method II, and comparing the re-
sults of the other three methods for all the three groups of products
analyzed, it is found that the plain acid method gives the highest
average results, 0.10, 0.26, and 0.15 percent, respectively, higher
than Jackson and Gillis method IV. The average figures by this last-
named method again exceed those of the invertase method by 0.28,
0.51, and 0.47 percent, respectively, owing to the differential effect
of reversion products and of amino compounds.
The application of the results, previously obtained with artificial
mixtures, to the analysis of actual cane products has thus shown
that Jackson and Gillis methods II and IV, used in conjunction with
the invertase method, give valuable indications with regard to the
relative quantities of reversion products and of amino acids present
in such products.
3. INVERTASE METHODS
(a) PREPARATION OF INVERTASE
The enzyme, invertase, which can be prepared simply and abun-
dantly from yeast, hydrolyzes sucrose under suitable conditions to
invert sugar. The invertase prepared from “top” or baker's yeast
inverts sucrose to invert sugar and also hydrolyzes raffinose to a
mixture of levulose and melibiose, while a similar preparation from
Polarimetry, Saccharimetry, and the Sugars 147
“bottom” or brewer's yeast contains also the enzyme, melibiase,
and hence possesses the additional power to hydrolyze melibiose to
a mixture of dextrose and galactose. It is thus possible, as Hudson
and Harding showed [37], to devise analytical processes for the de-
termination of sucrose and raffinose in their mixtures or in crude
beet-sugar products which contain them. :
The two stages of the hydrolysis may be expressed as follows:
I §: (invertase present)-- invert sugar.
‘l Raffinose (invertase present)—e levulose-Himelibiose.
II. Melibiose (melibiase present)—e galactose-H dextrose.
Reynolds [38] has given detailed directions for the preparation,
purification, and concentration of highly active invertase and meli-
biase solutions. For the preparation of invertase (free from melibiase),
10 pounds of baker's yeast are broken up and mixed with 5 liters of
water. Two liters of toluene are added and the mixture is stirred at
frequent intervals throughout the first 24 hours. The autolysis is
allowed to continue for 7 days. The extract is then filtered by
gravity on large fluted filters, yielding about 5 liters of filtrate. The
residue is mixed with 2 liters of water and filtered. The two filtrates
are combined and show usually an activity of k=0.028 (see p. 150)
The 7 liters of filtrate are transferred to the ultrafilter, described
below, concentrated to 1 liter, and washed with 1 liter of water. The
concentrated extract is removed from the ultrafilter, diluted again
to 7 liters, acidified with 14 ml of glacial acetic acid, and allowed to
stand overnight. This produces the precipitation of flocculent ma-
terial which is removed by slow filtration through paper. As soon as
a sufficient quantity of solution has filtered, it is transferred to the
ultrafilter and its concentration continued simultaneously with the
filtration from the flocculent precipitate. The extract is concentrated
to a volume of 800 ml. In an instance cited by Reynolds, the activity
of one such preparation was k=0.22.
For the preparation of invertase-melibiase 2.5 gallons of beer yeast
is filtered on a large Büchner funnel to remove the wort. About
5,500 g of compressed yeast containing about 23 percent of solids is
obtained. This is placed in a jar and 3 liters of toluene added. In a
few hours the yeast becomes liquid and autolysis is continued for
7 days, the liquid being agitated once or twice each day. The extract
is filtered by gravity on large fluted filters, yielding in 48 hours about
3 liters of filtrate. The residue is mixed with 1,200 ml of water, al-
lowed to stand overnight, and again filtered. The combined filtrates
should have an approximate volume of 4,200 ml and an activity of
k=0.0818. The crude extract is ultrafiltered to a volume of 600 to
700 ml and washed with 1 liter of water. It is then diluted to 4 liters,
treated with 8 ml of glacial acetic acid, and allowed to stand over-
night, filtration through fluted paper funnels being started the next
morning. Ultrafiltration is started as soon as sufficient filtrate has
accumulated and is continued until the volume has been reduced to
about 600 ml, whereupon it is washed with 3 liters of distilled water.
The final extract is, if necessary, filtered again through paper.
Reynolds found in one instance an invertase activity of k = 0.554 and
a melibiase activity of k=0.024. During ultrafiltration the solution
is stirred with a motor-driven stirrer; otherwise the enzyme is liable
to concentrate and precipitate at the membrane. Water should flow
148 Circular of the National Bureau of Standards
through the membrane at the rate of 500 ml per hour, but the enzyme
solution filters much more slowly, from 25 to 100 ml per hour, depend-
ing to some extent upon the vacuum applied. A membrane Once
properly prepared can be used continually for months and maintains
practically the same permeability. When not in use, it should be
kept covered with water to which a preservative has been added, e.g.,
a 1 : 2000 solution of chinosol.
(1) CollodroN ULTRAFILTER.—Dissolve 6 g of soluble (in alcohol
and ether mixture) pyroxylin or nitrocellulose, such as Astoria's, in a
mixture of 50 ml of absolute alcohol and 50 ml of absolute ether by
first adding the alcohol to the cotton, allowing the mixture to stand in a
stoppered flask for 10 minutes, adding the ether, and shaking. Allow
the solution to stand overnight, pour about 100 ml into a 2,000-ml
PARAF FIN OR VASE LINE
COLLODION MEMBRANE
FILTER PAPER
FIGURE 36.-Ultra filter for purification of enzymes.
cylinder, and coat the entire inside surface of the cylinder with the
collodion. Drain, and dry for 10 minutes. Fill with water, let stand
10 to 15 minutes, pour out the water and remove the collodion sack.
Test for leaks by filling with water. Slit open longitudinally and cut
out a circular piece about 7 to 8 inches in diameter. Cut the bottom
from a 2-liter bottle or Erlenmeyer flask and grind the edge smooth.
Place it upon the still moist collodion disk, fold the edge of the disk up
around the bottle, and cement it thereto with collodion that contains
an increased percentage of ether. Place three or four thicknesses of
wet filter paper in an 8-inch Büchner funnel. Place the bottle with
the collodion membrane upon the filter paper. Pour melted vaseline.
to the depth of 1 inch, between the bottle and inside of the funnel.
Provide the bottle with a small mechanical stirring device.
(2) WASHING AND ConCENTRATION OF INVERTASE SOLUTION BY
ULTRAFILTRATION.—Filter 4 liters of the partially purified solution


Polarimetry, Saccharimetry, and the Sugars 149
through the ultrafilter, stirring continuously, until about 1 liter
remains. , Wash with distilled water introduced by means of a
constant-level device until the filtrate is colorless, 3 or 4 liters of
wash water being required. During the entire process the invertase
Solution should be preserved with toluene.
The activity of the enzymes is in high degree dependent upon the
pH of the medium. The curve (fig. 37) shows the relative activity of
invertase as a function of pH. Michaelis and Davidson [39] found a
broad optimal zone of activity for the enzyme between pH 3.5 and 5.5.
Beyond these limits the activity diminished very rapidly. They
found the maximum activity at pH 4.2.
IO
9
IO 9 8 7 6 5 4. 3 2
P H —-
FIGURE 37.-Activity of invertase versus pH.
The purity of invertase preparations was expressed by O'Sullivan
and Thompson in terms of the “Time Value,” which represents the
number of minutes required for 0.05 g of a preparation to invert to the
point of zero rotation 4.0 g of sucrose in 25 ml of a solution containing
1 percent of dihydrogen sodium phosphate at 15.5° C. This point
corresponds to 75.75-percent hydrolysis.
Willstätter and Kuhn [40] introduced the term “Saccharase Unit,”
namely the amount of enzyme having the time value 1 in 0.05 g of the
invertase-containing substance acting under the definition of O'Sulli-
van and Thompson. Thus if a preparation containing 0.05 g of dry
substance inverts sucrose to the point of zero rotation in 1 minute, it
has 1 saccharase unit. Obviously, for the more active preparations
Smaller quantities of the enzyme are used for measurement, but the
results can be calculated to the units defined above.
The practical sugar analyst is usually less concerned with the purity
of his enzyme preparations than with their actual activity, which
depends partly on the purity and partly on their concentration. Con-
sequently he is not interested in expressing the activity in terms of

150 Circular of the National Bureau of Standards
dry substance. The following procedure is the official method of the
Association of Official Agricultural Chemists [18, p. 470.]
(3) ACTIVITY OF INVERTASE SOLUTION.—The following test for
activity of the invertase solution is usually adequate: Dilute 1 ml of
the invertase preparation to 200 ml. Transfer 10 g of sucrose (granu-
lated sugar) to a sugar flask graduated at 100 and 110 ml, dissolve in
about 75 ml of water, add 2 drops of glacial acetic acid, and dilute to
the 100-ml mark. To the 100 ml of sugar solution add 10 ml of the
dilute invertase solution and mix thoroughly and rapidly, noting the
exact time at which the solutions are mixed. At the termination of
exactly 60 minutes make a portion of the solution just distinctly alka-
line to litmus paper with anhydrous sodium carbonate and polarize
in a 200-mm tube at 20° C. If the invertase solution is sufficiently
active, the alkaline solution will polarize approximately 31° S without
correcting for the dilution to 110 ml and the optical activity of the
invertase solution.
If more exact information concerning the activity of the invertase
preparation is desired, determine its velocity constant as follows:
Dilute 1 ml of the invertase solution to 200 ml at 20°C; place in a
constant temperature bath at 20° C.; and when the solution has
attained the latter temperature, pipette 20 ml of it into a flask con-
taining 200 ml of a sucrose solution (10 g per 100-ml concentration)
that has been previously made distinctly acid to methyl red (corre-
sponding to approximately pH 4.6) by the addition of acetic acid,
and also brought to a temperature of 20° C in the same bath. Mix
thoroughly and promptly and note the time at which the invertase
solution was added. Keep the sucrose-invertase mixture in the
constant-temperature bath, remove portions at the end of 15, 30,
and 45 minutes; render each portion just distinctly alkaline to litmus
paper with anhydrous sodium carbonate immediately after removing,
and polarize at 20° C. Correct all polarizations for the polarization
of the invertase solution. Calculate the velocity constant, k, for
each of the polarizations (at the time, t) subsequent to the initial
polarization, using the following formula:
A logo1.32R-logo.(R,+032R)
--- f y
in which
k=the unimolecular reaction velocity constant,
t=number of minutes elapsing from the time the invertase
and sucrose solutions were mixed until inversion was
stopped by addition of sodium carbonate,
Ro–initial polarization (calculated by multiplying the polari-
zation of the sucrose solution by 10/11 and correcting
for the polarization of the invertase solution),
HR,-polarization at time t.
An invertase solution of sufficient activity should yield an average
value for k (for the various time periods) of at least 0.1 after multi-
plying the k value directly obtained by 200, in order to correct for
the initial dilution of the invertase solution. The dilution of the
invertase solution mentioned above is made solely for the purpose
of determining its activity. The original undiluted invertase solu-
tion is used as the inverting reagent in the determination of sucrose
Polarimetry, Saccharimetry, and the Sugars 151
unless the activity of the original invertase solution greatly exceeds
a k value of 0.1 and it is desirable to conserve the invertase. In
this case, dilute to a k value of 0.1, which is done in the same manner
as diluting other solutions to a standard strength. The activity of
the invertase preparation required for rapid inversion is the same
as that needed for overnight inversion, but the proportion of invertase
preparation used in the former case is twice that used in the latter.
(b) PURIFICATION OF INVERTASE BY ADSORPTION
Yeast invertase, in common with other enzymes, can be absorbed
on various suspended solid materials. Willstätter and Racke, whose
starting point was the autolysate according to Hudson, purified the
invertase by separating out impurities with kaolin which, in the
crude mixture, did not adsorb invertase. They then fractionally
adsorbed the enzyme with alumina in acid reaction with the addition
of acetone. The eluted and purified enzyme was then found to be
adsorbable by kaolin.
Adams and Hudson [41] have given in detail a method of adsorp-
tion by bentonite and subsequent elution. The following procedure
is typical: A fractional autolysis of baker's yeast was prepared by
treating 430 g of yeast (time value, 34.3) at 30°C with 43 ml of ether,
adding after the yeast had liquified 43 ml of toluene, 430 ml of water,
and 3.2 g of sodium can bonate, and 4 hours after the addition of the
ether, filtering through Filter-cel, with 80 g of Filter-cel added to
the mixture before filtration. The filtrate, which contained only
7.7 percent of the invertase, was discarded. To the residue was added
43 ml of toluene and 430 ml of water and autolysis was continued
for 5 days at 20° C. After filtration, this autolysate was dialyzed
immediately in Wisking sausage casings. To a mixture of 80 ml of
0.5 percent bentonite suspension and 27 ml of a solution at pH 4.1,
prepared by mixing 1 N acetic acid and 1 N sodium hydroxide was
added 265 ml of the dialyzed autolysate, which contained 7.53 units
of invertase per 100 ml and had a time value of 2.24 minutes. The
bentonite was separated by centrifuging, washed by stirring with
200 ml of distilled water, and again centrifuged. Ninety-two percent
of the invertase was adsorbed. Elution was effected by shaking
gently with 3 portions, 40, 30, and 20 ml, respectively, of an acetate
solution at pH 5.7, prepared from mixtures of 0.1 N acetic acid and
0.1 N sodium hydroxide solutions. The three extracts represented 57.8,
13.2, and 3.6 percent of the invertase in the original autolysate, and
after dialysis had time values of 0.216, 0.215, and 0.278 minute, and
contained 10.5, 2.26, and 0.64 units, respectively. The relatively
small change in pH between adsorption and elution requires careful
adjustment of the buffer solutions by colorimetric or electrometric
methods.
Richtmyer and Hudson [42] have described an alternative adsorp-
tion method with the use of zinc sulfide precipitated directly in the
invertase solution. They give in detail a typical preparation.
A baker's yeast of relatively high invertase content was allowed to
autolyze fractionally, in the manner described in the process, with
bentonite and the first fraction discarded. The main autolysate was
dialyzed in Wisking sausage casings and then represented 60 percent
of the original invertase in the yeast. To 1,940 ml of this solution,
152 Circular of the National Bureau of Standards
containing 110.2 invertase units, was added 1,940 ml of water, 43.5
ml of a 10-percent zinc acetate solution, 160 ml of a buffer solution
at pH 4.5 (made by mixing 2 N sodium hydroxide and 2 N acetic
acid), and 450 ml of a 10-percent sodium chloride solution (to prevent
the zinc sulfide from becoming colloidal). Hydrogen sulfide was
bubbled through the solution, and the zinc sulfide separated by cen-
trifuging; the supernatant liquid had a pH of 4.4 and contained only
6 percent of the invertase. The zinc sulfide was washed by shaking
with 1,500 ml of a 1-percent sodium chloride solution and again cen-
trifuged. The invertase was eluted by shaking with 400, 200, and
100-ml portions, respectively, of a solution containing 1 percent of
sodium chloride and 1-percent of mono- and dibasic ammonium
phosphate until it had a pH of 6.1. The combined extracts, after
dialysis, contained 77.6 invertase units, and had a time value of 0.20
unit.
Zinc sulfide has been used in similar fashion in purifying the dialyzed
autolysates of brewer's yeast of relatively low invertase content.
With these solutions a fractional adsorption with zinc sulfide is neces-
sary, 15 to 20 percent of the invertase being discarded in the first
portion. Adsorption and elution, as described, then produced inver-
tase solutions with time value 0.21 to 0.22 minute.
(c) INVERTASE DIVISOR
Paine and Balch [43] determined with care the values of the Clerget
divisor when pure sucrose is inverted with invertase. The basic
value, as determined, was found to be in essential agreement with that
previously measured by Zerban [44], and the values at other concen-
trations agreed with those of Ogilvie and of Hudson. Invertase from
both top and bottom yeasts was purified by the Reynolds method [38].
Measurements were made at widely varying concentrations of Sugar.
The relation between sucrose concentration and the divisor is
expressed by the equation
Divisor=131.17–1–0.073c,
in which c is the number of grams of sucrose in 100 ml.
The basic value of the divisor thus becomes 132.12 at 20° C.
Zerban found experimentally 132.10. Their concentration coefficient
0.072 is considerably at variance from the 0.082 determined by Jack-
son and McDonald (see p. 134).
4. DETAILED ANALYTICAL PROCEDURE
(a) CONSIDERATIONS GOVERNING THE CHOICE OF METHODS
The choice of a method of Clerget analysis depends largely upon
the purpose of the analysis, the nature of the material, and upon the
precision required. In general, it must be recognized that the only
methods completely free from limitations are those in which the
sucrose and raffinose are hydrolyzed by enzymes (see p. 159), and if
high precision and perfect selectivity are required, these methods alone
can insure a correct analysis. However, for the purely practical
considerations of the analyst's time and the expense of the enzymes,
these methods are confined largely to research projects.
Polarimetry, Saccharimetry, and the Sugars 153
The acid methods may be divided into two groups, the plain acid
methods (p. 154 and 155) and the compensation methods. The
compensation methods were devised, first, to eliminate errors in the
analysis of products high in invert-sugar content arising from the
increased rotation of the original invert sugar in the presence of acid,
and second, to eliminate errors caused by the change of rotation of
amino acids when highly acidified. Thus for the analysis of relatively
pure samples high in invert sugar Jackson and Gillis method IV
(p. 155) is to be recommended. For the analysis of samples con-
taining both invert sugar and amino acids Jackson and Gillis method
II (p. 154) is available.
There is, however, in many products of the sugar industry a group
of disaccharides or oligosaccharides which are not sucrose or raffinose
but are hydrolyzable by acids. The hydrolysis of these substances
introduces errors into the Clerget analysis which are obviously insur-
mountable except by the enzyme methods.
(b) REVISED METHODS OF JACKSON AND GILLIS
(1) GENERAL METHODS OF INVERSION.—The following methods of
inversion were designed to avoid destruction of invert sugar subse-
quent to the completion of the inversion. There is, however, a
variable amount of destruction during the process of inversion which
is unavoidable. Each method, therefore, requires the use of its ap-
propriate value of the Clerget divisor. These methods, which were
determined by inversion of pure sucrose, are in general applicable
to all products which do not contain considerable quantities of inor-
ganic salts of weak acids. They can be applied to cane molasses but
not to beet molasses. The latter should be inverted in a bath at
70° C, as described on page 155.
(a) Pipette 50 ml of the solution into a 100-ml flask, add 20 ml of
water and 10 ml of hydrochloric acid (dź” 1.1029 or 24.85° Brix at
20° C). Immerse in a water bath at 60° C. Agitate the solution
continually for about 3 minutes, and allow it to remain in the bath
for a total time of 9 minutes. Cool quickly. Basic value, 133.18.
(b) Pipette 70 ml of the solution into a 100-ml flask, add 10 ml of
hydrochloric acid (diº 1.1029) and proceed as in (a). Basic value,
133.18.
(c) Pipette 75 ml of the solution, add 10 ml of hydrochloric acid
(d;3° 1.1029) and proceed as in (a), but allow the solution to remain
a total time of 9.5 minutes. Basic value, 133.18.
(d) Pipette 50 ml and add 20 ml of water, or pipette 70 ml of the
solution, into a 100-ml flask, add 10 ml of acid, d: 1.1029, and allow
to remain 30.8 hours at 20°C, 14.6 hours at 25°C, or 7.1 hours at
30° C. Basic value, 133.28.
(e) Walker method. Transfer 50 ml and add 25 ml of water or
transfer 75 ml of the solution to a 100-ml flask and heat in a water
bath to 65° C. Remove from bath, add 10 ml of hydrochloric acid
(d. 1.1029), allow to cool spontaneously for 15 minutes, and cool
to the temperature of polarization. In the case of low-grade products
containing an excess of basic lead acetate, add previous to heating,
1 ml (or 2 ml if excess of lead is large) of the acid used for inversion.
Basic value, 133.18 (tentative).
154 Circular of the National Bureau of Standards
(2) METHOD I.-(Applicable to pure sucrose, or to sugar mixtures
in * the impurities are unaffected optically by hydrochloric
8,O1Cl.
Reagents. Hydrochloric acid (diº 1.1029 or 24.85 Brix).
Prepare a normal solution of the sample or a solution of such
fractional normality as the nature of the substance will permit.
Defecate, if necessary, with basic lead acetate in the usual manner,
making to volume at the temperature at which the observations are
to be made, and filter.
(If desired, the excess of lead may be removed at this point by the
addition of pulverized potassium or sodium oxalate. However, it is
necessary that the whole filtrate be treated by the deleading reagent,
since the latter exerts an effect upon the rotation of invert sugar
which should be as far as possible offset by a similar effect on sucrose.)
Polarize the solution to obtain the direct reading and, if necessary,
correct to the value which would have been obtained if 26 g of the
sample were taken in 100 ml of solution.
To obtain the invert polarization, invert as described on page 153.
make to a volume of, 100 ml at the temperature at which the observa-
tions are to be made, and polarize. Correct the observed polarization
to that of a normal solution. The algebraic difference between the
two polarizations corrected for dilution gives the value P-P'. De-
termine by refractometer the dry-substance concentration of the
original sample and calculate the weight of solids, m, taken for the
invert polarization.
Calculate the percentage of sucrose by the formula
S= P. P. º
TBasic value--0.0794 (m—13)—0.53(t–20)
The basic value is 133.18 for inversion at 60°C or 133.28 for room-
temperature inversion.
(3) METHOD II.-(General method applicable to all products.)
Reagents. Hydrochloric acid (d. 1.1029 or 24.85 Brix); ammonium
hydroxide solution, 5 to 6 N; solution of ammonium chloride contain-
ing 226 g per liter; pulverized potassium or sodium oxalate.
Ascertain by at least three concordant titrations in the presence of
methyl orange the volume of the ammonia solution required to neutral-
ize 10 ml of the hydrochloric acid.
Prepare a normal solution of the sample or a solution of such
fractional normality as the nature of the substance will permit. Defe-
cate, if necessary, with basic lead acetate in the usual manner, making
ºme at the temperature at which the observations are to be made.
ilter.
(If desired, the solution may at this point be freed from lead; but
if this is done, the deleading reagent must be added to the whole filtrate.
Finely pulverized potassium oxalate in minimum quantity is added
until precipitation is complete. Filter. If this procedure is omitted,
the lead is precipitated satisfactorily by the chlorides added later.)
Pipette into two 100-ml flasks two equal volumes of the filtrate
(50, 70, or 75 ml).
For the direct polarization, add to 1 portion 15 ml of the ammonium
chloride solution or 3.392 g of dry ammonium chloride. Make to
volume at the temperature at which the observations are to be made;
filter, if necessary, and polarize.
Polarimetry, Saccharimetry, and the Sugars 155
For the invert polarization, add hydrochloric acid to the other
portion and invert by one of the methods described on page 153. Cool
Quickly. After the solution has become quite cold add from a burette
during continual shaking, the precisely determined volume of am-
monia required to neutralize the acid. Adjust the temperature,
make to volume, filter, if necessary, and polarize at carefully con-
trolled temperature. Correct both polarizations to the normal weight
of sample.
Calculate the percentage of sucrose by the formula
S= P. P/ .
Basic value-F0,0794.(m-13)=0.53(H2O).”
in which m is the weight of dry substance taken for invert polarization.
The basic value of the divisor is 133.27 for 60° C inversion or 133.37
for room-temperature inversion.
(4) METHOD Iv.—(Applicable in the presence of invert sugar, but
inapplicable in the presence of optically active non-sugars which
change rotation with acidity. In principle sodium chloride equalizes
the effect of hydrochloric acid on invert sugar present as an impurity.)
Prepare a normal solution of the sample or a solution of such
fractional normality as the nature of the substance will permit.
Defecate, if necessary, with basic lead acetate in the usual manner,
making to volume at the temperature at which the observations are
to be made. Filter. -
(If desired, the excess of lead may be removed at this point. Add
pulverized potassium or sodium oxalate to complete precipitation of
lead. The deleading reagent should be added to the whole filtrate.
If the deleading is omitted, the lead is satisfactorily removed by the
chlorides subsequently added.)
Pipette two 70-ml (or 50 ml–H20 ml of water) portions of the clear
filtrate into two 100-ml flasks. If preferred, 75-ml portions may be
taken.
To 1 portion add 2.315 g of sodium chloride or 7.145 ml of a saturated
sodium chloride solution or 10 ml of a solution containing 231.5 g per
liter; make to volume at the temperature at which the observations
are to be made and polarize.
To the other portion add hydrochloric acid and invert by one of the
methods described on page 153. Cool and make to volume at the
temperature at which the observations are to be made. Polarize.
Correct both rotations to the normal weight of sample.
Calculate the percentage of sucrose by the formula
S= P_P'
Basic value-E0.0794.(n −13)=0.53(f-20)'
in which m is the weight of dry substance taken for the invert polari-
zation. The basic value is 132.56 for 60° C inversion or 132.66 for
room-temperature inversion.
(c) ACID METHODS OF THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS
(1) DETERMINATION OF SUCROSE BY Pola RIZATION BEFORE AND
AFTER INVERSION WITH HYDROCHLoRIC ACID.—(In the presence of
much levulose, as in honeys, fruit products, sorghum sirup, cane sirup,
156 Circular of the National Bureau of Standards
and molasses, the optical method for sucrose, requiring hydrolysis by
acid, gives erroneous results.)
Direct reading.—Proceed as directed under “Direct reading,” page
157.
Invert reading.—Pipette a 50-ml portion of the lead-free filtrate
into a 100-ml flask and add 25 ml of water. Then add, little by little,
while rotating the flask, 10 ml of hydrochloric acid (sp. gr. 1.1029
at 20°/4° or 24.85° Brix at 20°C). Heat a water bath to 70°C and
regulate the burner so that the temperature of the bath remains
approximately at that point. Place the flask in the water bath,
insert a thermometer, and heat with constant agitation until the
thermometer in the flask indicates 67°C. (This preliminary heating
period should require from 2% to 2% minutes). From the moment
the thermometer in the flask indicates 67°C, leave the flask in the
bath for exactly 5 minutes longer, during which time the temperature
should gradually rise to about 69.5°C. Plunge the flask at once into
water at 20°C. When the contents have cooled to about 35°C,
remove the thermometer from the flask, rinse it, and fill almost to the
mark. Leave the flask in the bath at 20°C for at least 30 minutes
longer and finally make up exactly to volume. Mix well and polarize
the solution in a 200-mm tube provided with a lateral branch and a
water jacket, maintaining a temperature of 20°C. This reading must
also be multiplied by 2 to obtain the invert reading. If it is necessary
to work at a temperature other than 20°C, which is permissible within
narrow limits, the volumes must be completed, and both direct and
invert polarizations must be made at exactly the same temperature.
Calculate sucrose by the following formula:
100(P– I)
S= 143+0.0676 (m—13) —0.53t'
in which
S=percentage of sucrose,
P= direct reading, normal solution,
I=invert reading, normal solution,
t=temperature at which readings are made,
m=grams of total solids from original sample in 100 ml of
the invert solution.
Determine with the refractometer the total solids as percentage by
weight, as directed on page 258, and multiply this figure by the den-
sity at 20°C, as obtained from table 113, page 626.
Inversion at room temperature.—The inversion may also be accom-
plished as follows: (1) To 50 ml of the clarified solution, freed from
lead, add 10 ml of hydrochloric acid (sp. gr. 1.1029 at 20°/4° or 24.85°
Brix at 20°C) and set aside for 24 hours at a temperature not below
20°C; or, (2) if the temperature is above 25°C, set aside for 10 hours.
Make up to 100 ml at 20°C and polarize. Under these conditions,
the formula must be changed to the following:
S= 100(P–I) *-
143.2-i-0.0676(m—13) —0.53t’
(2) DETERMINATION OF SUCROSE AND RAFFINos E BY POLARIZATION
BEForL AND AFTER INVERSION WITH HYDRoch Loric ACID.—(Of value
chiefly in the analysis of beet products.) If the direct reading is
Polarimetry, Saccharimetry, and the Sugars 157
more than 1% higher than the percentage of sucrose, as calculated by
the formulas given on p. 156, raffinose is probably present. Calculate
sucrose and raffinose by the following formulas:
When the polarizations are made at 20°C,
_0.514P— I _0.33P+ I
S=*#H+ and R="####,
in which
P=direct reading, normal solution,
I=invert reading, normal solution,
S=percentage of sucrose,
R=percentage of anhydrous raffinose.
The following formulas are applicable at all temperatures:
S_P(0.478+0.0018t)–I(1,006–0.0003t)
(0.908–0.0032tº) (1.006–0.0003t) '
p_P(0.43–0.005b)+1(1,006–0.00035)
(1.681–0.0059t,) (1.006–0.0003t) '
in which •
P= direct reading, normal solution,
I = invert reading, normal solution,
S= percentage of sucrose,
R= percentage of anhydrous raffinose,
t = temperature of the direct polarization,
tº = temperature of the invert polarization.
See also discussion of Creydt's raffinose formula on page 143.
(d) INVERTASE METHODS OF THE ASSOCIATION OF OFFICIAL AGRICULTURAL
CHEMISTS
(1) DETERMINATION OF SUCROSE.
Direct reading.—Dissolve the double-normal weight of the substance
(52 g), or a fraction thereof, in water in a 200-ml volumetric flask;
add the necessary clarifying agent, avoiding any excess; shake, dilute
to the mark with water, mix well, and filter, keeping the funnel
covered with a watch glass. Reject the first 25 ml of the filtrate.
If a lead clarifying agent was used, remove the excess lead from the
solution when sufficient filtrate has collected, by adding anhydrous
Sodium carbonate a little at a time, avoiding any excess; mix well and
filter again, rejecting the first 25 ml of the filtrate. (Instead of weigh-
ing 52 g into a 200-ml flask, two 26-g portions may be diluted to 100 ml
each and treated exactly as described. Depending on the color of the
product, multiples or fractions of the normal weight may be used
and the results reduced by calculation to the basis of 26 g in 100 ml.)
Pipette one 50-ml portion of the lead-free filtrate into a 100-ml flask,
dilute with water to the mark, mix well, and polarize in a 200-mm
tube. The result, multiplied by 2, is the direct reading (P of formula
given below), or polarization before inversion. (If a 400-mm tube is
used the reading equals P.) If there is a possibility of mutarotation,
allow sufficient time for its completion.
Invert reading.—First determine the quantity of acetic acid neces-
sary to render 50 ml of the lead-free filtrate distinctly acid to methyl
323414°–42—12
158 Circular of the National Bureau of Standards
red indicator, pH 4.4; then to another 50 ml of the lead-free solution
in a 100-ml volumetric flask, add the requisite quantity of acid and
5 ml of the invertase preparation, fill the flask with water nearly to
100 ml, and let stand overnight (preferably at a temperature not less
than 20° C). Cool, and dilute to 100 ml at 20° C. Mix well and
polarize at 20°C in a 200-mm tube. If there is doubt as to the com-
pletion of the hydrolysis, allow a portion of the solution to remain for
averal hours and again polarize. If there is no change from the
previous reading, the inversion is complete. Carefully note the
reading and temperature of the solution. If it is necessary to work at
a temperature other than 20°C, which is permissible within narrow
limits, complete the volumes and make both direct and invert readings
at the same temperature. Correct the polarization for the optical
activity of the invertase solution and multiply by 2. Calculate the
percentage of sucrose by the formula
142.1 +0.073 (m—13)—tſ2’
in which
S=percentage of sucrose,
P= direct reading, normal solution,
I =invert reading, normal solution,
t=temperature at which readings are made,
m=g of total solids from original sample in 100 ml of the invert
solution.
Determine with the refractometer the total solids as a percentage
by weight, as directed on page 258, and multiply this figure by the
density at 20°C, as obtained from table 113, p. 626.
Rapid inversion at 55° to 60° C.–If more rapid inversion is desired,
proceed as follows: Prepare the sample as directed under “direct
reading,’’ p. 157, and to 50 ml of the lead-free filtrate in a 100 ml
volumetric flask add glacial acetic acid in sufficient quantity to render
the solution distinctly acid to methyl red, pH 4.4. The quantity of
acetic acid required should be determined before pipetting the 50-ml
portion, as described in the preceding paragraph. Then add 10 ml
of invertase solution, mix thoroughly, place the flask in a water bath
at 55° to 60°C, and allow to stand at that temperature for 15 minutes
with occasional shaking. Cool, add sodium carbonate until dis-
tinctly alkaline to litmus paper, dilute to 100 ml at 20°C, mix well,
and determine the polarization at 20° C in a 200-mm tube. Allow
the solution to remain in the tube for 10 minutes and again determine
the polarization. If there is no change from the previous reading,
the mutarotation is complete. Carefully note the reading and the
temperature of the solution. Correct the polarization for the optical
activity of the invertase solution and multiply by 2. Calculate the
percentage of sucrose by the formula given above.
If the solution has been rendered so alkaline as to cause destruction
of sugar, the polarization, if negative, will in general decrease, since
the decomposition of fructose ordinarily is more rapid than that of the
other sugars present. If the solution has not been made sufficiently
alkaline to complete mutarotation quickly, the polarization, if nega-
tive, will in general increase. As the analyst gains experience he may
omit the polarization after 10 minutes, if he has satisfied himself
Polarimetry, Saccharimetry, and the Sugars 159
that he is adding sodium carbonate in sufficient amount to complete
mutarotation at Once without causing any destruction of sugar during
the period intervening before polarization.
(2) SUCROSE AND RAFFINOSE BY POLARIZATION BEFORE AND AFTER
TREATMENT WITH Two ENzYME PREPARATIONS.
Invertase solution (top-yeast extract). —Prepare as directed on
page 147. This solution should be free from the enzyme melibiase.
Its invertase activity should be at least as great as that used for the
determination of sucrose in the absence of raffinose.
Invertase-melibiase solution (bottom-yeast extract).—Prepare as di-
rected on page 147, using bottom fermenting yeast (brewers' yeast)
instead of bakers' yeast. The invertase activity should be at least as
great as that from the top-yeast extract.
Test the melibiase activity of the solution as follows. Add 2 ml
of the solution to be tested to 20 ml of a weakly acid melibiose solution
polarizing +20.0° S and allow to stand 30 minutes at about 20° C.
Then add sufficient sodium carbonate to render the solution slightly
alkaline to litmus paper. A preparation suitable for the overnight
hydrolysis of solutions containing not more than 0.2 g of raffinose in
100 ml should hydrolyze 35 percent of the melibiose present under the
conditions mentioned; a preparation suitable for the overnight hydroly-
sis of solutions containing not more than 0.65 g of raffinose in 100 ml
should produce 50-percent hydrolysis of melibiose; and a preparation
suitable for the overnight hydrolysis of solutions containing 0.65 to
1.3 g of raffinose in 100 ml should hydrolyze at least 70 percent of the
melibiose present under the above condition. The polarizations that
correspond to 35-, 50-, and 70-percent hydrolysis of a melibiose solu-
tion polarizing, before hydrolysis, +20° are +16.4°, + 14.9°, and
+12.9° S, respectively.
Determination.—In the analysis of sugar-beet products, weigh the
quantity of material specified in table 19, transfer to a 300-ml volu-
metric flask, add the quantity of basic lead acetate solution indicated
in the table, and dilute to volume at 20° C. Mix thoroughly and filter
through fluted paper in a closely covered funnel, rejecting the first 25
ml of filtrate. When sufficient filtrate has collected, remove the lead
from the solution by adding ammonium acid phosphate in as Small
excess as possible (see table 19). This condition is readily determined,
after a little practice, by the appearance of the lead phosphate pre-
cipitate, which usually flocculates and settles rapidly in the presence
of a slight excess of the salt. Mix well and filter, again rejecting at
least the first 25 ml of the filtrate. Make a direct polarization in a
200-mm tube at 20°C, unless the solution contains an appreciable
quantity of invert sugar, in which case pipette a 50-ml portion of the
lead-free filtrate into a 100-ml flask, dilute with water to the mark,
mix well, and polarize at 20°C, preferably in a 400-mm tube. This
reading, calculated to the normal weight of 26 g in 100 ml and 200-mm
tube length, is the direct reading (P) of the formula given in table 19
for polarization before inversion.
Transfer two 50-ml portions of the lead-free filtrate to 100-ml
flasks. To one add 5 ml of invertase solution (top-yeast extract),
page 147, and to the other add 5 ml of invertase-melibiase solution
(bottom-yeast extract), page 147, let stand overnight at atmospheric
temperature (preferably not below 20° C), dilute to volume, mix well,
and polarize at 20°C, preferably in a 400-mm jacketed tube. If a
160 Circular of the National Bureau of Standards
TABLE 19.-Quantity of sample and reagents required for clarification and deleading
of beet sugar-house products
* +-ry Basic lead Ammonium
Material Quº per acetate dihydrogen
(55° Brix) phosphate
7ml
Cossettes'------------------------------------------------ 13 3 '2
*P------------------------------------------------------ 100 ml 2 to ... 2
Lime cake or sewer 3---------------- - - - - - - - - - - - - - - - - - - - - - -- 26. 52 1, 54 (4)
Thinjuice------------------------------------------------ 52 2 . 2 to 0.3
Thick juice----------------------------------------------- 26 4 . 3 to . 4
White massecuite------------------- - - - - - - - - - - - - - - - - - - - - - - 13 Or 26 3 Or 6 . 3 to . 7
High Wash Sirup----------------------- - - - - - - - - - - - - - - - - - - - 13 Or 26 3 Or 6 . 3 to . 7
High green sirup------------------------------------------ 13 Or 26 5 Or 10 . 3 to . 7
Raw Gr'remelt massecuite--------------------------------- 13 6 . 3 to . 4
Raw or remelt Sugar-------------------------------------- 26 3 to 4 . 3 to . 4
Sugar melter---------------------------------------------- 26 2 to 3 . 3 to . 4
LOW Wash sirup------------------- - - - - - - - - - - - - - - - - - - - - - - - - 13 8 to 10 . 4 to . 5
Low green sirup or molasses------------------------------ 13 10 . 4 to . 5
Saccharate cakes and milk (carbonated) - - - --------------- 26 4 to 6 . 3 to . 4
Steffen waste and wash waters 3 - - - - --------------------- 78 or 50 ml 2 to 3 ... 2
! Usual method of extraction, 26 g in 201.2 ml.
2 Dilute to 110 ml.
* Neutralize with acetic acid before adding basic lead acetate.
* Lime in solution will be precipitated partly by the phosphate, and it is necessary to add sufficient phos-
phate to complete the precipitation of both the lead and lime salts; hence no definite quantity can be specified.
rapid hydrolysis is desired, add 10 ml of each of the enzyme solutions
to the 50-ml portions of deleaded filtrate in 100-ml flasks, and place in
a water bath at 50° to 55°C for 40 minutes. Then add sodium car-
bonate until the solution is slightly alkaline to litmus paper, dilute
to volume at 20°C, mix well, and polarize at 20°C, preferably in a
400-mm tube. Correct the invert readings for the optical activity
of the enzyme solution, and calculate the polarization to that of a
normal-weight solution of 26 g in 100 ml; also calculate the reading to a
200-mm tube length, if necessary.
Calculate the percentages of anhydrous raffinose and sucrose from
the formula
R=1.354 (A–B),
S== (P–2.202A-L 1.209B) 100
TI32.12–0.00718II32.12 (P-2.202AEI2O2B)]’
in which
R=percentage of raffinose,
S=percentage of sucrose,
P= direct polarization, normal solution,
A=corrected polarization after top-yeast hydrolysis, normal
solution,
B=corrected polarization after bottom-yeast hydrolysis,
normal solution. A and B are treated algebraically.
(e) DOUBLE-ACID METHOD OF OSBORN AND ZISCH
Osborn and Zisch [31], finding the double-enzyme method reliable
in the analysis of beet products, but impracticable because of the
expense of the enzymes and the difficulty of obtaining satisfactory
preparations, sought to modify the methods of acid hydrolysis in such
manner as to make them suitable for routine analysis. They pointed
out that the direct polarization is the resultant rotation of sucrose,
Polarimetry, Saccharimetry, and the Sugars 161
raffinose, and a group of optically active nonsugars consisting mainly
of amino acids. The rotation of the latter group they called the N
value. The presence of three unknown quantities required three
equations for their solution. They found, in agreement with Paine
and Balch [45] and with Zerban [46], that the rotation of the nonsugars
became zero in strongly acid solution but was restored to its original
value by neutralization. If, therefore, the invert polarization was
observed in both acid and neutral solution, the difference between
the two readings became a measure of N. This fact had previously
been stated by Zerban, who observed that the difference between
Jackson and Gillis methods II and IV was a measure of the optically
active amino compounds, but he did not apply the principle to a
quantitative method of analysis.
(1) Procedure.—Transfer 130 g of the sample, or its equivalent, to a
500-ml Kohlrausch flask, add the necessary basic lead acetate, and
make to 400 to 450 ml with water. Deaerate under vacuum until all
visible gas bubbles are removed, using a few drops of ether or amyl
alcohol to break the foam, if necessary. Make to 500 ml at 20°C,
mix, and filter. Delead the filtrate with the minimum of powdered
ammonium dihydrogen phosphate, and filter, using a little filter aid if
º; Polarize in a 200-mm tube to obtain the direct polariza-
tion, P.
Pipette 50 ml of the deleaded filtrate into each of two 100-ml
Kohlrausch flasks. Add 15 ml of water and heat to 68° to 69°C in a
70° C water bath. Remove from bath, and immediately add 10 ml
of hydrochloric acid (dº. 1.1029). Allow to cool spontaneously for 2
hours, and then cool to 20° C. Make the one invert to 100 ml at
20°C, mix, filter if necessary, and polarize at 20°C in a 400-mm tube,
the reading being the invert polarization, I. To the second invert,
add 1 or 2 drops of 0.2 percent methyl red indicator solution and
neutralize with 6.34 N ammonium hydroxide, adding the ammonia
very slowly from a burette while constantly whirling the flask. Then
add exactly 1 ml in excess. Make to 100 ml at 20°C, filter if necessary,
and polarize in a 400-mm tube to obtain the neutralized invert polari-
zation, I’.
The N value, sucrose, and raffinose are then calculated by the
formulas
N= I’—I-I-K,
P’ = P-N,
S = 0.514 P’ — I 0.514P" – I
T0.514 T(0.321-E0.00009S) 0.835+0.00009S'
R=0.54 (P’—S),
in which
N=polarizing effect of the optically active nonsugars,
P’ = true direct polarization of the raffinose and sucrose,
S=percentage of sucrose,
R=percentage of raffinose,
K=neutralization correction=0.0047S+0.00017Sv, in which
v is the number of milliliters of basic lead (55 Brix)
added per 100 ml. It is satisfactory to use Pinstead of S.
NOTES.—The correction, K, is required because the negative rotation of invert
sugar is enhanced to a higher negative value upon neutralization with ammonia.
It also includes the effect of ammonium acetate, which varies with the volume of
162 Circular of the National Bureau of Standards
lead acetate added. The numerical values of K are conveniently tabulated in the
original article.
Not more than a few drops of amyl alcohol should be added, since it is optically
active.
Cover filters during filtration, and discard the first 10 to 15 ml of each filtrate.
No more ammonium phosphate than necessary should be used, since 1 g per 100
ml depresses the direct polarization by 0.35°S.
The authors restrict the method to beet products subsequent to the carbonation
stage. It proved applicable to such products in a wide geographical territory,
centering in Colorado, but not to those from California. It cannot be applied to
any mixture containing invert sugar.
With the application of the method thus restricted, the authors found excellent
agreement between this and the double-enzyme method. It proved inexpensive
and well adapted to routine analysis. The average value of N for 28 samples of
beet molasses from both Steffen and non-Steffen factories, proved to be — 1.62 by
the double-acid method, and — 1.71 by the double-enzyme method. The average
sucrose content agreed within 0.01 percent and raffinose within 0.06 percent. The
International Commission for Uniform Methods of Sugar Analysis in 1936 found
the method too restricted in its application to justify adoption. It is to be noted,
however, that the method of Osborn and Zisch is the first successful attempt to
find the necessary third equation for the solution of the three unknown quantities
in the composition of beet products, even though somewhat restricted in its
application.
(f) METHODS OF OTHER NATIONS
Much effort has been devoted to the elimination of the effect of
optically active amino acids on the Clerget analysis. These nitrog-
enous substances exhibit one rotatory power in a neutral or alkaline
medium and a quite different one in acid medium. It was, therefore,
recognized early that both direct and invert polarizations must be
made in the same medium in respect to hydrogen-ion concentration.
These efforts have been directed in two ways, namely to read both
solutions in neutral solution or both in acid solution.
In the early experiments, Pellet sought to equalize the effect by
acidifying the direct polarization with sulfur dioxide. The acidity of
such a solution, however, is too weak to affect the rotation of the amino
acids to the same degree as the hydrochloric acid of the invert polariza-
tion. Andrlik observed the direct polarization in the presence of
hydrochloric acid to which urea was added in such quantity as to slow
the hydrolysis of sucrose. This interesting expedient has caused much
discussion but has not been put into general use.
A more promising method was proposed by Stanek [47], who
inverted with hydrochloric acid in the usual way, but upon completion
of the inversion added potassium citrate stoichiometrically equivalent
to the hydrochloric acid, causing the formation of potassium chloride
and citric acid. To the direct polarization was added the same mixture,
it being determined that the citric acid, having but 1.72 percent of the
inverting power of hydrochloric acid, produced no appreciable effect
upon the sucrose. Stanek found a Clerget divisor of 132.66 at 20° C.
The official methods in Czechoslovakia specify the Stanek method,
with the rounded-off divisor 132.6 for sucrose determinations in beet
molasses.
Babinski and Ablamowicz [48] utilized the Stanek principle, but
substituted sodium acetate for potassium citrate. The method was
officially adopted in Poland, with a basic value of 131.46 for the divisor.
Both Stanek and Babinski clarified the solutions by the addition of
Saturated (3-percent) bromine water. This is stated to give good
clarification and rapid filtration. The precipitate amounts, with
molasses, to about 0.1 g and, therefore, its influence on the con-
Polarimetry, Saccharimetry, and the Sugars 163
centration of the sample is negligible. The objecton to its use is the
disagreeable odor and corrosive effect of free bromine.
In order to make use of the Stanek-Babinsky principle, Schlemmer
[49] studied the clarification with Aktivin or Chloramin-T, which
reacts with water as follows:
Cl H
/ /
CH3( >SO, N + H2O= CH3( >SO2N + NaCl-HO
N N
Na. H
In combination with sodium bromide, the oxygen set free releases
two atoms of bromine from the sodium bromide. The released bromine
clarifies the solution which, after filtration, remains clear for about
% hour. The precipitate from beet molasses weighs about 0.15 g. No
odor of bromine is appreciable. .
The following solutions are required:
(a) Hydrochloric acid, 18.38 percent; d = 1.092. .
(b) Sodium acetate, 400 g; and potassium bromide, 50 g in 1 liter.
(c) A solution containing about 15 percent of Chloramin-T.
(d) A mixture of solutions (a) and (b) in the ratio 20 ml of (b) to
10 ml. of (a).
Procedure for beet molasses.—Transfer 52 g of molasses to a 200-ml
flask and fill to the mark at 20°. Mix thoroughly, and pipette two
50-ml portions to 100-ml flasks. To one add 30 ml of solution (d).
Add 10 ml of solution (c). Adjust to 20°, mix, filter, and polarize at
20°. To the other solution add 10 ml of solution (a), invert according
to Schrefeld’s method (page 129), cool, and add 20 ml of solution (b).
Add in 3 portions 10 ml of solution (c), make to volume at 20°C, filter,
and polarize at 20°.
Schlemmer determined the value of the divisor for one-half-, one-
fourth-, and one-eighth-normal solutions of sucrose and, surprisingly
enough, found no variation with concentration. He reported the
values 131.98 for pure sucrose and 131.75 at 20° for final beet molasses.
Apparently no measures are taken in these methods to evaluate the
raffinose content of beet products.
Steuerwald [50] devised a method, extensively used in the Dutch
East Indies, in which the inversion is carried out at room temperature
by hydrochloric acid of such high concentration that the reaction is
completed without the attention of the analyst within 2 or 3 hours.
The direct polarization is observed in the usual manner.
For the invert polarization, measure 50 ml of the clarified filtrate
with a 100-ml flask, and add 30 ml of hydrochloric acid of 1.1 sp. gr
(acid of 1.188 sp gr diluted with an equal volume of water). Set
aside for 3 hours if the temperature is between 20° and 25°C or for 2
hours if above 25°. Dilute the solution to 100 ml and polarize at a
carefully observed temperature. Calculate both polarizations in
terms of the normal weight of the sample in 100 ml.
Calculate the percentage of sucrose by the formula
*-*. 100(P–P') *
T 145.54–H 0.0676 (m—13)—0.53t
Jackson and Gillis [3, p. 168] showed that the high basic value of the
Steuerwald divisor was consistent with their own and other values of
the divisor if the effect of the acid is considered.
S
164 Circular of the National Bureau of Standards
If the sample contains a considerable quantity of invert sugar it
would seem probable that the Steuerwald method would yield high
results for sucrose, since the effect of the acid is to increase greatly
the negative rotation of original invert sugar in the invert polarization.
This effect is uncompensated.
5. REFERENCES
. T. Clerget, Ann. chim. phys. [3] 26, 175 (1849).
. A. Browne, J. Assn. Official Agr. Chem. 2, 134 (1916).
. F. Jackson and C. L. Gillis, Sci. Pap. BS 16, 141 (1920) S375.
. Herzfeld, Z. Ver. deut. Zucker-Ind. 38, 699 (1888).
. Dammiller, Z. Ver. deut. Zucker-Ind. 38, 746 (1888).
. S. Walker, Sugar 17, 47 (1915).
. M. Tolman, Bul. Bur. Chem. 73, 73 (1903).
L. G. L. Steuerwald, Int. Sugar J. 16, 82 (1914).
R. F. Jackson and C. L. Gillis, Z. Ver, deut. Zucker-Ind. 70, 521 (1920).
O. Schrefeld, Z. Ver. deut. Zucker-Ind. 70, 402 (1920).
O. º Zablinsky, and A. Wolf, Z. Wirtschaftsgruppe Zuckerind. 86,
670 (1936).
| H. S. Walker, J. Ind. Eng. Chem. 9, 490 (1917).
[13] S. Arrhenius, Z. physik. Chem. 4, 230 (1889).
[14] O. Gubbe, Ber. deut. chem. Ges. 18, 2207 (1885).
[15] R. F. Jackson and E. J. McDonald, J. Assn. Official Agr. Chem. 22, 580 (1939).
[16] C. Tuchschmidt, Z. Ver. deut. Zucker-Ind. 20, 649 (1870).
[17] R. Gillet, Z Ver. deut. Zucker-Ind. 64, 271 (1914).
[18] Official and Tentative Methods of Analysis of the Association Official Agri-
cultural Chemists, 3d ed. (1935).
[19] W. C. Vosburgh, J. Am. Chem. Soc. 43, 219 (1921).
[20] F. W. Zerban, J. Assn. Official Agr. Chem. 8, 384 (1925); 11, 167 (1928).
[21] E. von Lippmann, Die Chemie der Zuckerarten, 11, 1188, (Vieweg u. Sohn,
Braunschweig, 1904).
[22] R. F. Jackson and C. L. Gillis, Louisiana Planter 66, 380 (1921); Facts
About Sugar 13, 10 (1921); Int. Sugar J. 23, 445 (1921).
[23] C. A. #º Louisiana Planter 66, 171 (1921); Facts About Sugar 12,
230 (1921).
[24] R. J. Brown, Ind. Eng. Chem. 17, 39 (1925).
25] C. A. Browne, J. Assn. Official Agr. Chem. 2, 138 (1916).
26] E. Saillard, Eighth Int. Cong. Applied Chem. Communication 25, 541 (1912).
27] E. Saillard, J. fab. Sucre (May 22, 1912 and July 1, 1914); Z. Wer. deut.
Zucker-Ind. 64, 841 (1914).
28] F. W. Zerban and C. A. Gamble, Ind. Eng. Chem., Anal. Ed. 5, 34 (1933).
29] R. Creydt, Z. Ver. deut. Zucker-Ind. 37, 153 (1887).
30] C. A. Browne and C. A. Gamble, J. Ind. Eng. Chem. 13, 793 (1921).
31] S. J. Osborn and J. H. Zisch, Ind. Eng. Chem., Anal. Ed. 6, 193 (1934).
[32] F. W. Zerban and C. A. Gamble, Ind. Eng. Chem., Anal. Ed. 5, 34 (1933).
[33] F. W. Zerban, J. Assn. Official Agr. Chem. 8, 384 (1925); 9, 166 (1926); 10,
183 (1927); 11, 167 (1928); 12, 158 (1929); 13, 188 (1930); 14, 172 (1931).
[34] F. W. Zerban, Orig. Com. Eighth Int. Cong. Applied Chem. 8, 103 (1912).
[35] J. A. Ambler, Int. Sugar J. 29, 439 (1927).
[36] C. A. Browne and R. E. Blouin, Louisiana Sugar Expt. Sta. Bul. 91, 93 (1907).
[37] C. S. Hudson and T. S. Harding, J. Ind. Eng. Chem. 7, 2193 (1915).
[38] F. W. Reynolds, Ind. Eng. Chem. 16, 169 (1924).
[39] L. Michaelis and H. Davidsohn, Biochem. Z. 35, 386 (1911).
[40] R. Willstätter and R. Kuhn, Ber. deut. chem. Ges. 56, 509 (1923).
[41] M. Adams and C. S. Hudson, J. Am. Chem. Soc. 60, 982 (1938).
[42] N. K. Richtmyer and C. S. Hudson, J. Am. Chem. Soc. 60, 983 (1938).
[43]. H. S. Paine and R. T. Balch, J. Am. Chem. Soc. 49, 1019 (1927).
[44] F. W. Zerban, J. Am. Chem. Soc. 47, 1104 (1925).
[45] H. S. Paine and R. T. Balch, J. Ind. Eng. Chem. 17, 240 (1925).
[46] F. W. Zerban, J. Assn. Official Agr. Chem. 12, 158 (1929).
[47] W. Stanek, Z. Zuckerind. Böhmen 38, 429 (1914); Int. Sugar J. 16, 387 (1914).
J. Babinski and W. Ablomowicz, Gez. Ceur. 1914–15, T44, S10, 147.
[49] J. Schlemmer, Z. Zuckerind. Čechoslovak. Rep. 53, 13 (1928).
[50] I. Steuerwald, Arch. Suikerind. 21, 831 (1913). Int. Sugar J. 15, 489 (1913).
M
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T
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Polarimetry, Saccharimetry, and the Sugars 165
IX. CHEMICAL METHODS FOR THE DETERMINATION OF
REDUCING SUGARS
1. THEORETICAL AND GENERAL
(a) INTRODUCTION
The history of the growth of reducing-sugar analysis begins in
1815, when Vogel showed that the reddish precipitate produced by
boiling copper acetate with honey was not metallic copper, as had
previously been supposed, but was cuprous oxide. From this small
beginning the development was slow, with the major steps in progress
decades apart. In 1841 Trommer found that, by making the copper
solution alkaline, not only was a differentiation of sugars made pos-
sible, but the sensitivity was increased. In 1838 a French society
offered a prize for a successful method of quantitative estimation of
sugar, and an award of a portion of the prize was made in 1844 to
Barreswil, who adapted Trommer's qualitative method to a quan-
titative method of analysis. He also showed that cane sugar could
be determined by observing its reducing power before and after
inversion.
In 1849 H. Fehling [1] worked out with great care the details of the
method, giving some account of the stoichiometrical equivalents.
Fehling believed that one molecule of glucose reduced five equivalents
of copper, not recognizing that the reaction is quantitative only
within narrow limits of concentration and time of reaction. Fehling's
method proved satisfactory in respect to sensitivity and repro-
ducibility of analysis, but the copper solution was unstable.
Soxhlet [2] effected still further improvements, utilizing the same
reagents in the same proportions as Fehling, but preserving the
copper solution and the alkaline tartrate solution in separate containers
until required for analysis. This solution and method have been
utilized up to the present day.
(b) REDUCING SUGARS IN ALKALINE SOLUTION
When glucose, levulose, or mannose is subjected to the action of
dilute alkali in aqueous solution, the three sugars undergo a mutual
conversion into each other until an equilibrium is established.* The
composition of this mixture is the same regardless of the sugar taken
as the starting material. These relations were shown in a very strik-
ing manner by Lobry de Bruyn and van Ekenstein [3], who applied
the same conditions to other sugars and found equilibria between
galactose, talose, and tagatose, and in many other systems. This
reaction is a perfectly general one and is of practical value for the
conversion of readily available sugars into new sugars or into sugars
of less common occurrence.
The mechanism of the reaction has been studied extensively.
Nef [4] showed that a hexose in alkaline solution was converted into
a 1,2-enediol (I). He accounted for the final products by assuming
that, to this enediol, water can be added in three different ways:
The hydroxyl may attach to the terminal carbon atom, yielding the
aldehyde group; the hydrogen attaching to the second carbon atom
8 The reactions occurring in alkaline solution, and briefly indicated in this and succeeding paragraphs, are
too involved to describe in detail. The purpose here is to show the nature of the reactions rather than their
aCCurate COUrSe.
166 Circular of the National Bureau of Standards
by rupture of either one of the bonds, yielding either of two aldoses;
or the hydroxyl may attach to the second carbon atom and yield,
with elimination of water, the ketose.
chon chon choi choi
COH COH CHOH CHOH
choi con con co
choi choi con choi
biſon bion choi CHOH
choi chon choi choi
I II III IV
*
Wolfrom and Lewis [5], working with tetramethylglucopyranose,
observed that true equilibrium was apparently established between
glucose and mannose but that no ketose appeared to be formed.
On this basis they considered the reaction to consist of a simple enoliza-
tion and regeneration of the carbonyl group. Thus
cho chon chon cho
OI’
Hºoh-ºoh-º-o Hoºh
On more prolonged action of the alkali, the enediols may descend
to the 2,3 position (II), or to the 3,4 position (III). The latter yields
a 3-ketose, known as glutose (IV), which, since the hydroxyl on the
second carbon may previously have undergone transformation, occurs
in two forms, alpha and beta glutose. As a result of overliming or of
high local concentrations of lime in the processes of cane-sugar manu-
facture, glutose is frequently found in cane molasses to the extent of
several percent. It has about one-half the reducing power of dextrose
and is unfermentable by yeast.
If the alkalinity of the solution is greatly increased, still more deep-
seated changes occur in the reducing-sugar molecule, and saccharinic
acids and their lactones are formed, of which there are 24 isomers
theoretically possible.
In the presence of oxidizing agents, such as cupric salts in alkaline
solution, the enediols are strongly reducing and can take up oxygen
at the expense of copper, thereby reducing it to cuprous oxide. Accord-
ing to Nef’s theory [4], a momentary dissociation of the molecule
occurs at the position of the double bond and each fragment takes up
oxygen to yield the corresponding hydroxy acid. Since the enediol
may, at the time the molecule is ruptured, be either at the 1,2; 2,3;
or 3,4 position, and since the hydroxyls may have altered their rela-
tive position, the number of different acids produced is large. Man-
nose, glucose, and levulose all give the same oxidation products in the
presence of sodium and cupric hydroxides, namely carbon dioxide,
formic, glycolic, d,l-glycerinic, l-threonic, and d-erythronic, d-mann-
onic, d-gluconic, cº-hydroxy-methyl-d-arabonic, and the pentonic acids.
(c) COPPER-TARTRATE COMPLEXES
If a solution of copper sulfate is added to a chemically equivalent
Solution of sodium tartrate, cupric tartrate is precipitated and may be
Polarimetry, Saccharimetry, and the Sugars 167
isolated. If to this cupric tartrate one equivalent of sodium hydroxide
is added, the insoluble cupric tartrate dissolves to form a deep-blue
solution that is neutral to litmus, indicating that the whole cupric
tartrate residue has behaved as an anion to neutralize the alkali. This
is further shown by the migration of copper to the anode upon elec-
trolysis. Cupric salts behave in a similar manner with many other
substances, such as citrates, oxalates, Salicylates, carbonates, glycerol,
and cane Sugar.
Fortunately, this property of forming soluble complexes is confined
to the cupric salts, for, when under the influence of reducing reagents
the copper is reduced to the cuprous state, the latter, being unable to
form such complexes, precipitates in the alkaline solution in the form
of cuprous oxide.
For the preparation of reagents suitable for sugar analysis, the
alkali must be in excess of one equivalent of alkali to one of cupric
tartrate, for the enolization occurs only in alkaline solutions.
(d) CLASSIFICATION: OF REDUCING SUGARS
The sugar group may be classified with respect to reducing power
into three classes: Nonreducing Sugars, such as sucrose and raffinose;
monosaccharides, such as glucose, levulose, and xylose; reducing di-
saccharides, such as lactose and maltose. The nonreducing sugars
lack the free aldehyde or lactonyl structure which is characteristic of
reducing sugars. The reducing disaccharides possess the reducing
group on only one of the hexose residues. During the reduction it is
this residue which is mainly subject to oxidation; consequently the
disaccharides have but little more than half the reducing power pos-
sessed by the monosaccharides.
(e) MODERN INVESTIGATIONS
Subsequent to the work of Fehling and of Soxhlet, which laid the
foundation for accurate analytical processes, variations of procedure
and of composition of the alkaline copper solutions were proposed in
great number in an effort to effect still further improvements. Many
of these modifications served a useful purpose in their day, but almost
all have been displaced in modern times by the unified methods. The
early tendency was to devise a particular method for each sugar under
examination. This necessitated the use of different reagents and dif-
ferent procedures and, when the sample contained a mixture of sugars,
rendered an interpolation of copper equivalents impossible. These
difficulties led to the establishment of unified methods of procedure,
whereby the same reagents and procedure were used, regardless of the
nature of the sugar. Empirical copper equivalents were then deter-
mined for the sugars of common occurrence. This unification of
methods has caused most of the older methods to become obsolete.
However, the latter are of historical interest and, in some instances,
of intrinsic value, and they are frequently useful to the specialized
worker.”
Quisumbing and Thomas [6] have investigated the reduction reac-
tion in detail, studying in particular the results caused by varying the
* A list of the many alkaline copper solutions which were devised during this early period is given in
Wiley’s Agricultural Analysis, 1st ed. Vol. 3, p. 183. Some of the more valuable early methods are described
in Browne’s Handbook of Sugar Analysis, 1st ed., p. 388 (1912).
168 Circular of the National Bureau of Standards
composition of the alkaline copper reagent. The nature and concen-
tration of alkali influence both the amount of reduction and the
physical character of the cuprous oxide. Sodium hydroxide and
potassium hydroxide solutions of equivalent concentrations yield
practically the same reduction with the hexoses, but potassium
hydroxide causes a higher reduction with maltose than sodium
hydroxide. In general, sodium hydroxide yields the more satisfac-
tory precipitate in respect to physical characteristics.
When the concentration of alkali is varied, the amount of copper
reduced by sugars rises sharply as the alkalinity is increased from zero
and reaches a maximum at about 1.6 N, the normality being referred
to the mixed copper reagents. Around this concentration of alkali
the curve is relatively flat, so that considerable variations in alka-
linity produce inappreciable effects. The Fehling-Soxhlet tartrate
Solution, which is so commonly employed, is about 1.2 N with respect
to alkali. It has not exactly the optimum composition, but it is
nevertheless situated on a portion of the curve at which the amount of
copper precipitated varies but slightly with the concentration of
alkali. It is remarkable that Fehling, groping about in an effort to
devise a system of analysis, should have aimed so nearly true. At
higher concentrations of alkali the amount of copper reduced dimin-
ishes, slightly in the case of hexoses, considerably more with maltose
and lactose.
Since, as was indicated in a previous paragraph, the reactions of
reducing sugars are very complex, it follows that there is no exact
stoichiometrical relation between the sugar and reduced copper.
In the early stages of the reaction very rapid changes occur, and in
fact the maximum rate of reduction occurs at about 75° C. The
products of these first stages of oxidation are also capable of reducing
copper but at a much slower rate. The result is that the reduction
of copper continues, even if the time of reaction is greatly prolonged.
All practical methods therefore necessarily require that the time of
reaction be strictly defined. The time of reaction may be arbitrarily
chosen, but must be definite. Since the reaction starts at a relatively
low temperature, the preliminary stages of heating are important and
the conditions should be carefully controlled.
As is well known, sucrose possesses an appreciable reducing power
in alkaline solution. The source of its reducing action is obscure but
is generally ascribed to a slight hydrolysis by hydroxyl ions. The
reducing power increases rapidly with the alkalinity of the solution.
Hence the Soxhlet and similar solutions containing caustic alkali
are more strongly reduced by sucrose than those which contain alkali
carbonates. In the analysis of relatively pure samples of sucrose, the
reduction by the sucrose itself is frequently of such magnitude that it
greatly masks that of the contaminating reducing sugar. This has
led from very early times to the employment of the more weakly
alkaline carbonate solutions for the analysis of sucrose samples.
Even with such solutions, sucrose exhibits a measurable reducing
power. In the preparation of sucrose for the establishment of polari-
scopic standards, Bates and Jackson [7] showed that the reducing
reaction of sucrose was different from that caused by true reducing
sugar, for sucrose yielded weights of reduced copper increasing linearly
with the time of reaction, while the reduction by reducing sugar was
practically complete in the early stages of the reaction. The carbonate
Polarimetry, Saccharimetry, and the Sugars 169
**
Solutions are used almost exclusively in the determination of reducing
Sugar in biological preparations. The alkalinity is supplied by carbo-
nates or bicarbonates, or their mixtures.
Somogyi [8] and Shaffer and Somogyi [9] studied the copper reduc-
tion in mixed carbonate-bicarbonate solutions, particularly with
reference to the ratio of carbonate to bicarbonate. They found that
the characteristic feature was that when the alkalinity was lower (or
the ratio Na2CO3:NaHCO3, was lower) the sugar oxidation was
slower but that the final amount of copper reduced was higher. The
maximum reduction of copper was found to vary inversely with the
logarithm of the carbonate: bicarbonate ratio. The rate of reduction
conforms roughly with a first-order equation and may be treated as a
pseudomonomolecular reaction. The velocity of copper reduction
(and of sugar oxidation) is likewise a linear function of the logarithm
of the carbonate: bicarbonate ratio and thus presumably of pH.
Shaffer and Somogyi showed that the rate of oxidation varied with
the nature of the sugar. With a copper solution having a carbonate: bi-
carbonate ratio of 1, the rate of reduction diminishes in the order (1)
fructose, (2) glucose, (3) galactose, maltose, and arabinose, (4) lactose,
and (5) mannose. It is thus necessary to extend the period of heating
in the analysis of slowly reacting sugars.
For precise analytical work it is important to prepare the caustic
alkali solutions with sodium hydroxide which is free from carbonate.
This can be done in a simple manner by preparing a 50-percent solution
(by weight) of the sodium hydroxide and allowing it to stand until
the carbonate has separated. The solution is then decanted or filtered
through asbestos, and a weighed quantity (about 1 g) is titrated
against a standard acid. The 50-percent alkali is about 19.3 N.
(f) CLARIFICATION OF CRUDE PRODUCTS
Crude natural products and the crude products of the sugar industry
require clarification as a preliminary step in the determination of
reducing sugars. Basic lead acetate is unsuitable for this purpose,
since it precipitates appreciable amounts of reducing sugar. Normal
lead acetate, however, while it does not usually produce a filtrate of
sufficient brilliancy for polariscopic analysis, meets the requirements
of chemical methods of reducing-sugar analysis, for it precipitates
colloidal material and aids in the removal of suspensions and material
which would otherwise contaminate the precipitated copper. Lane
and Eynon [10], in an investigation of its action in the analysis of the
products of the cane-sugar industry, found no instance in which it
removed reducing substances.
Of even more importance than the removal of the substances men-
tioned above is the removal of calcium salts. Lane and Eynon have
shown that all of the alkaline earths exert an inhibiting effect on the
reduction of copper and may cause errors in excess of 5 percent by
their retarding action. The deficiency of copper reduced is equally
apparent in gravimetric and volumetric methods. An excess of calcium
salts renders the end point in the presence of methylene blue indistinct.
In order to remove both lead and calcium salts the filtrate from the
lead defecation should be treated either with a 10-percent solution of
potassium oxalate or with dry, finely powdered sodium or potassium
oxalate. If the former is used, the volume relations must be accurately
170 Circular of the National Bureau of Standards
observed by diluting to one-tenth greater volume or by some similar
procedure. If dry sodium oxalate is used, the original volume of the
filtrate is not altered unless large quantities of calcium salts are present.
2. METHODS WHICH REQUIRE FILTRATION OF CUPROUS OXIDE
(a) MUNSON AND WALKER UNIFIED METHOD [11]
This method, which is in more general use in this country than any
other gravimetric method is applicable to any sample containing re-
ducing sugars. Tables were prepared by the authors for the more
common sugars and sugar mixtures and can be extended to other
sugars as the need arises without modification of procedure. Success
with this method depends in great measure upon attention to details.
If copper or copper oxide is to be weighed, the asbestos must be
prepared with care to remove substances soluble in the caustic re-
agents, and assurance must be had that the precipitate is uncontami-
nated. If crude substances are under examination, the copper should
not be weighed but should be determined analytically. In ordinary
practice the simplicity and directness of procedure tend to encourage .
careless operation, and errors in results are charged against the method.
If the concentration of sugar in the sample is subject to control, it is
advisable to use the higher ranges of the tables.
(1) PREPARATION OF SoxHLET REAGENTs. * Copper sulfate solu-
tion.—Dissolve 34.639 g of pure copper sulfate crystals in water and
dilute to 500 ml.
Alkaline tartrate solution.—Dissolve 173 g of Rochelle salt and 50 g
of sodium hydroxide in water, and dilute to 500 ml.
(2) PROCEDURE.-Transfer 25 ml each of the copper and alkaline
tartrate solutions to a 400-ml Jena or Pyrex beaker, and add 50 ml of
reducing-sugar solution, or if a smaller volume of sugar solution is
used, add water to make the final volume 100 ml. Heat the beaker
upon an asbestos gauze over a Bunsen burner, so regulate the flame
that boiling begins in 4 minutes, and continue the boiling for exactly
2 minutes. Keep they beaker covered with a watch glass throughout
the entire time of heating. Without diluting, filter the cuprous oxide
at once on an asbestos mat in a Gooch crucible, using suction. Wash
the cuprous oxide thoroughly with water at a temperature of about
60° C, then with 10 ml of alcohol, and finally with 10 ml of ether.
Dry for 30 minutes at 100°C, coolin a desiccator, and weigh as cuprous
oxide. If the precipitate is contaminated, determine copper analyt-
ically by one of the methods described on page 178. Refer the weight
of copper to the Munson and Walker table (table 78, p. 564) to
determine the weight of the sugar in the sample.
(b) HAMMOND REDETERMINATION OF THE MUNSON AND WALKER VALUES
In the years that followed the Fehling proposal in 1849 [1] to use
an alkaline copper tartrate solution for the quantitative estimation
of reducing sugars, many methods were proposed in which various
modifications of the concentrations of the components of the Fehling
reagent and of the period of boiling the sugar solution and reagent
were used. In 1906 Munson and Walker [11] surveyed the various
methods and proposed one to unify all the others. This method has
deservedly gained widespread use because of its simplicity and ex-
Tºcommonly known as Fehling’s Solution.
Polarimetry, Saccharimetry, and the Sugars 171
treme reproducibility of results. Despite the wide utilization of
the Munson and Walker table for commercial and scientific purposes,
there has been neither a redetermination of their original values
nor any needed additions to the scope of the table in 33 years.
Since improved methods for producing pure sucrose and dextrose
are easily available, the original Munson and Walker values were
redetermined with high precision, and since it is now possible to
produce pure levulose by the methods of this Bureau [12] the reducing
values of this sugar were also determined.
Within the past few years there has been imported into this country
a new twpe of molasses product made by the partial hydrolysis of
raw cane-Sugar solution and boiling to a thick sirup. Samples received
at this Bureau have a composition varying between 70 to 82 percent
total sugar and a reducing-sugar content from 45 to 58 percent.
When a sample of this product is taken for analysis to give a total
Sugar content of 0.4 g in 50 ml of solution, the concentration of re-
ducing sugar is such that the limits of the Munson and Walker table
are exceeded. Until the thorough revision and additions to the
table were made by Hammond [13] it was necessary to add sucrose
to the sample to reduce its invert-sugar content. In order to be
able directly to weigh a sample, it was decided to determine data
for a new column in the table by using a mixture of invert sugar
and sucrose having a total sugar content of 0.3 g.
In redetermining these values, as well as in determining the new
ones, the conditions of the Munson-Walker method were rigorously
followed and the same concentration of copper reagent was used.
However, certain changes in technique were soon found to be necessary.
Munson and Walker brought the solution to boiling by heating over
a gas flame. This procedure was changed to use electric heating.
When the 400-ml beaker was placed in the heater, the 100 ml of
solution it contained was entirely surrounded in a nest of the resistance
wire. When gas is used to heat such a mixture, a yellow substance
often forms on the side of the beaker. This yellow deposit is
ordinarily formed when low-grade sugar products, such as blackstrap
molasses, are to be analyzed, but has never been observed when the
heating is done electrically. The current was controlled by means
of a General Radio Corporation Variac and a Raytheon voltage
regulator. The solution could readily be brought to boiling in the
prescribed 4-minute interval (+5 sec).
Munson and Walker transferred the precipitated cuprous oxide
to Gooch crucibles and weighed the cuprous oxide. This procedure
was abandoned and the copper determined electrolytically. The
cuprous oxide was transferred to a Gooch crucible, washed, and then
dissolved by the slow dropwise addition of 5 ml of 1:1 nitric acid.
The copper nitrate was received in a 250-ml beaker; 10 ml of 1:1
nitric acid was added as well as about 5 g of ammonium sulfate.
Enough water to cover conveniently the cylindrical gauze electrodes
was added, making the total volume of electrolyte about 180 ml.
The electrolysis was conducted at a current density of approximately
0.10 amp/dm”, and, upon completion, the electrolyte was displaced
with distilled water before breaking the current. The copper deposit
was washed with alcohol, dried 15 minutes at 100° C, cooled in a
desiccator, and weighed. All deposits were bright and showed no
trace of “burning.”
172 Circular of the National Bureau of Standards
Munson and Walker prepared the invert-sugar solution by hydro-
lyzing a sucrose solution with 0.02 N. hydrochloric acid and, upon
completion of the hydrolysis, neutralizing with 0.2 N sodium hydrox-
ide. In the investigation by Hammond, the invert solution was
made by taking equal weights of crystalline dextrose and levulose.
The levulose was prepared by taking a purified sample and dis-
Solving it in water to make a 50-percent solution. Vegetable carbon
was added and the solution heated. The filtered solution was
evaporated in vacuo to a thick sirup, seeded with pure levulose, and
crystallized in motion. The crystals were centrifuged and then
washed with absolute alcohol. After drying in the air, the crystals
were pulverized, dried for 2 hours at 50° C, and finally dried and
stored in a vacuum desiccator. A polariscopic examination showed
the levulose to be pure.
The sucrose and dextrose used in this work were Standard Samples
17 and 41, respectively, issued by this Bureau.
The same intervals of concentrations of the sugars employed by
Munson and Walker were used, and fresh solutions were made for
each determination by weighing the requisite amount of sugar into a
sugar scoop, transferring to a 500-ml flask, and completing the volume
at 20° C, at which temperature the solution was kept while the
aliquots of 50 ml were taken. For the concentration 20 mg per 50
ml, the amounts of sugar necessary for 1 liter of solution were taken.
Quadruplicate determinations of each sugar concentration were made.
From the average result of each series of quadruplicate determina-
tions there was calculated by the method of least squares a set of
equations for calculating the reducing sugar from any given weight
of copper within the limits of the method. In table 78 in the Appendix
are shown the reducing-sugar values for each sugar and sugar mixture
for values of copper from 10 to 440 mg at intervals of 1 mg. The
values for cuprous oxide were computed by multiplying the corre-
sponding value for copper by the factor 1.12585.
Attention is called to the fact that for the columns 0.3 g and 0.4
g of total sugar in table 78, the values are practically identical beyond
the concentration of 220 mg. This is probably due to the fact that as
the copper content of the copper reagent diminishes during the 2-min-
ute boiling period, the rate of the reaction decreases, so that the dif-
ferences are of a magnitude approximating the experimental error of
the method. A comparison of the copper values of the Munson and
Walker table and those of the new table show the Munson-Walker
values to be slightly higher for a definite weight of sugar. The dif-
ferences for dextrose are a few tenths of a milligram, distributed
positively and negatively. For invert sugar and the invert-sugar and
sucrose mixtures the differences are somewhat larger and, in general,
increase with the sugar concentration. It is to be noted that if a
comparison is made between a definite weight of copper and the cor-
responding sugar value, the sugar value in the new table will be
higher than that in the Munson and Walker table.
In a critical study of the Munson-Walker method, Jackson and
McDonald [35] have shown that cuprous oxide is contaminated with
organic decomposition products, even when pure sugars are analyzed,
and that the amount of this contamination is almost exactly equal to
º difference between Hammond’s and Munson and Walker’s copper
Value.S.
Polarimetry, Saccharimetry, and the Sugars 173
(c) ALLIHN METHOD FOR THE DETERMINATION OF DExTROSE [14, 15.
Copper sulfate solution.—Dissolve 34.639 g of CuSO4.5H2O in water
and dilute to 500 ml.
Alkaline tartrate solution.—Dissolve 173 g of Rochelle salt and 125 g
of potassium hydroxide in water and dilute to 500 ml.
Description of method.—Place 30 ml of the copper solution, 30 ml
of the alkaline tartrate solution, and 60 ml of water in a beaker, and
heat to boiling. Add 25 ml of the sugar solution, which must be so
prepared as to contain not more than 0.25 g of dextrose, and boil for
exactly 2 minutes, keeping the beaker covered. Filter immediately
through asbestos without diluting and obtain the weight of copper by
one of the methods described on pages 178–185. The corresponding
weight of dextrose is found from the Allihn table (table 79, p. 584).
Quisumbing and Thomas found that the maximum amount of
copper was reduced at a concentration of caustic alkali of 0.8125 N.
Soxhlet's copper mixture is 0.625 N, whereas Allihn’s solution is
0.922 N with respect to potassium hydroxide, the calculated normality
being referred in each instance to the final reaction mixture containing
the sugar. That all three solutions are within the range of high
sensitivity is shown by the fact that in spite of varied conditions of
analysis they all reduce approximately the same weight of copper.
Thus 100 mg of dextrose reduces respectively 201.5, 198, and 195 mg
of copper.
(d) QUISUMBING AND THOMAS METHOD
The method of Quisumbing and Thomas [6] was devised after a
careful study of the fundamental properties of the reaction had
revealed the most favorable conditions for conducting the analysis.
In order to obviate the autoreduction of the alkaline copper solution
and the reduction of copper by sucrose, and to avoid variations in
temperature caused by changes of barometric pressure, the reduction
reaction was carried out in a water bath at 80° C. Preliminary
experiments had shown that the maximum reduction occurs at an
alkalinity of 1.6 N and at a ratio of 5 to 6 of sodium hydroxide to 1 of
copper. Fifty milliliters of mixed reagent should thus contain 3.2 g
of sodium hydroxide and from 0.525 to 0.630 g of copper. With
greater concentrations of copper, the total reduction is decreased,
while the autoreduction is increased. The concentration of Rochelle
salt employed in the Soxhlet reagent was retained.
This method is capable of producing more accurate results than
any other gravimetric method. No reduction of copper is caused by
sucrose if the sample does not contain more than 400 mg. In its
present form the method is limited to materials of low sucrose content.
It should be possible, however, to extend the application of the method
to samples of high sucrose content by determining the corrections at
higher sucrose concentrations. In view of its independence of
barometric pressure, the method is useful at high altitudes. -
Copper sulfate solution.—Dissolve 41.2 g of CuSO4·5H2O and dilute
to 500 ml. The crystals should be free from dust or partially
dehydrated salt.
Alkaline tartrate solution.—Dissolve 173 g of crystallized Rochelle
salt in water in a 500-ml flask, and add the calculated amount of
sodium hydroxide solution containing 65 g of Sodium hydroxide.
323414°–42 13
174 Circular of the National Bureau of Standards
Fill to a volume of 500 ml. The alkali solution is freed from car-
bonates in the manner described on page 169.
General procedure.—Measure accurately 25 ml each of the copper
sulfate and alkaline tartrate solutions into a 400-ml Pyrex-glass beaker,
the diameter of which is about 9 cm. Add 50 ml of sugar Solution
containing 50 to 150 mg of dextrose, levulose, or invert Sugar; or 100 to
300 mg of lactose or maltose. Cover the beaker with a watch
glass, and place the beaker in a water bath maintained at 80° C.
After digesting for exactly 30 minutes, filter the cuprous oxide by
suction through a mat of asbestos in a Gooch crucible. Wash the
precipitate in the usual manner and determine the copper by one of the
methods described on page 178.
From the weight of copper or cuprous oxide obtained, find the cor-
responding weight of reducing sugar from table 80, p. 586.
(e) BERTRAND METHOD
This method [16] has been but little used in the United States. It is
more widely employed in Europe, more frequently in the pure chemis-
try of carbohydrates than in commercial analysis.
The reagents are prepared as follows:
(a) 40 g of pure CuSO4.5H2O dissolved to 1 liter.
(b) 200 g of Rochelle salt and 150 g of sodium hydroxide dissolved to
1 liter.
Into a 150-ml Erlenmeyer flask transfer 20 ml each of solutions (a)
and (b) and 20 ml of the sugar solution, which should contain not more
than 100 mg of reducing sugars. Heat to boiling and keep at gentle
ebullition for exactly 3 minutes. Filter through asbestos and deter-
mine the reduced copper as follows by Mohr’s volumetric perman-
ganate titration. Reference table 81 is given on page 587. Transfer
the asbestos film to the beaker, add about 30 ml of hot water, and heat
the precipitate and asbestos thoroughly. Rinse the crucible with 50
ml of a hot saturated solution of ferric sulfate in 20-percent sulfuric
acid, receiving the rinsings in the beaker containing the precipitate.
After the cuprous oxide is dissolved, wash the solution into a large
Erlenmeyer flask, and immediately titrate with a standard solution of
potassium permanganate. One milliliter of the permanganate solu-
tion (0.1573 N) should equal 0.010 g of copper. Standardize the
permanganate against pure sodium oxalate.
(f) HERZFELD METHOD FOR DETERMINATION OF LESS THAN 1.5 PERCENT OF
INVERT SUGAR IN SUCROSE
Many of the products of the cane-and beet-sugar industries, particu-
larly in the later stages of the processes, contain small residual quan-
tities of invert sugar which cannot be accurately determined by the
Meissl and Hiller method. The Herzfeld method [17] is designed to
apply to this range of concentrations. It therefore serves to supple-
ment the Meissl and Hiller method (p. 175), which is serviceable at
ratios of invert sugar to sucrose greater than 1% percent. In his
fundamental research, Herzfeld determined the copper reduced by a
10–g sample of total sugar containing varying quantities of added
invert sugar, collecting the precipitated copper in a thick-walled filter
tube (12 by 2 cm) containing 1.5 cm of asbestos supported by a
platinum cone. The cuprous oxide was burned at low heat to cupric
Polarimetry, Saccharimetry, and the Sugars 175
oxide in order to destroy precipitated organic matter and then reduced
to copper in a stream of hydrogen. Herzfeld’s procedure, in spite of
its early date, thus corresponds to modern procedure. He made
triplicate or quadruplicate determinations at seven ratios of invert
Sugar to sucrose and plotted a smooth curve through the determined
points.
The method is well adapted to the determination of reducing sugar
in the higher grades of commercial raw sugar. These in general
require a preliminary clarification with normal lead acetate. This
can be conveniently done by weighing out a 20-g sample, transferring
to a 100-ml flask, adding normal lead acetate, making to volume, and
filtering. To the filtrate, dust in sufficient dry sodium oxalate to
precipitate the excess lead and filter. A volume of 50 ml of the filtrate
will contain 10 g of the original sample.
An alternative method [18] is to dissolve 44 g of the sample and
transfer to a 200-ml volumetric flask. Clarify with normal lead
acetate, make to volume, and filter. Measure 100 ml of the filtrate
into a 100- to 110-ml flask, add sufficient sodium sulfate to precipitate
the excess lead, and filter. Take for analysis 50 ml of the filtrate.
Add the 50-ml solution thus prepared to 50 ml of mixed Soxhlet
solution and heat rapidly to boiling. From the moment when the
boiling becomes vigorous continue the boiling for exactly 2 minutes.
Then add 100 ml of cold water freed from air by previous boiling
and collect the precipitated copper by filtration and thorough
washing. Determine the copper by any of the usual methods (p. 178).
Refer the weight of copper to table 82.
It was recognized by Herzfeld that the influence of sucrose upon the
amount of copper reduced was relatively considerable and variable.
Much of the variability was ascribed to the variable degree of super-
heating of the sugar solution during the period of boiling. Vondrak
[19] in a careful study showed that the boiling temperature of the
reaction mixture rose to 104° to 105°C, but the addition of talcum
or roughened glass beads diminished the boiling temperature to 102°C
and, moreover, the analytical results were far more reliable than those
obtained by the original method. He sought to improve the proce-
dure by using glass beads, 5 to 6 mm in diameter, which had been
roughened by vigorous shaking in a stout bottle for 10 minutes with
2 percent of coarse carborundum (No. 100). These beads can be
used repeatedly if after each use they are again shaken with carborun-
dum for 5 minutes.
The analysis is conducted as prescribed by Herzfeld, with the excep-
tion that five roughened glass beads are added to the reaction mixture.
The reducing action of sucrose is diminished and consequently a
revision of Herzfeld’s table (table 83, p. 589) was required. Inter-
polation between adjacent values of copper yields accurate results.
(g) MEISSL AND HILLER METHOD FOR DETERMINING INVERT SUGAR ADMIXED
WITH SUCROSE IN ALL PROPORTIONS
At a very early period Meissl recognized the importance of correct-
ing the precipitated copper for the reducing action of sucrose. Meissl
and Wein determined the reducing powers of mixtures containing less
than 10 percent of invert sugar. In order to extend the applicability
of the principle, Hiller [20] determined the reducing action of invert
sugar in the presence of widely varying quantities of sucrose and con-
176 Circular of the National Bureau of Standards
structed a table of factors by which the weight of copper should be
multiplied in order to yield invert sugar correctly in the presence of
all ratios of sucrose to invert sugar up to 99 percent. Hiller's table of
factors (p. 589) illustrates well the effect of sucrose. Each column
gives the factors (expressed in percent) for a constant weight of invert
Sugar in the presence of varying quantities of sucrose. In extreme
cases an error of nearly 30 percent could be introduced by disregarding
the effect of sucrose.
In order to select the proper factor, it is necessary to determine
polariscopically the approximate sucrose content of the sample. The
direct polarization in the presence of invert sugar is not a correct
measure of sucrose but is sufficiently exact for the purpose, except in
very low-grade products. If the sucrose is determined by the Clerget
method, its percentage should be substituted for P, the direct polariza-
tion, in the formulas given below.
The Hiller factors were carefully determined, but not with the rigid
specifications which are imposed at the present time. He used Fehling
solution, boiled “2 to 3 minutes,” and collected the precipitate on a
paper filter, ignited, and reduced the oxide by hydrogen to copper.
It is not essential that enough solution be taken to precipitate nearly
all of the copper, but, in general, the results are more accurate at
higher than at lower sugar concentrations.
Prepare a solution of suitable concentration of the material to be
examined, clarify with neutral lead acetate, and remove the excess of
lead with an alkali oxalate or sodium phosphate. Prepare a series of
solutions in large test tubes by adding 1, 2, 3, 4, and 5 ml of this
solution to each tube successively. Add 5 ml of mixed Soxhlet reagent
to each, heat to boiling, boil 2 minutes, and filter. Note the volume
of sugar Solution that gives the filtrate lightest in tint but still dis-
tinctly blue. Place 20 times this volume of the sugar solution in a
100-ml flask, dilute to the mark, and mix well.
Transfer 50 ml of mixed Soxhlet reagent and 50 ml of the solution
to a 250-ml beaker. Heat this mixture at such a rate that a period
of approximately 4 minutes is required to bring it to the boiling point,
and then boil for exactly 2 minutes. Add 100 ml of cold recently boiled
water. Filter immediately through asbestos, and determine the copper
by one of the methods described on page 178.
Let
Cu + the weight of copper obtained,
P=polarization of the sample (or sucrose by Clerget analysis),
W= the weight of the sample in the 50 ml of solution used for
the determination,
F= the factor obtained from Hiller’s table.
Then
º = Z, approximate weight of invert Sugar,
ZX º = Y, approximate percentage of invert Sugar,
1905. R, approximate percentage of sucrose in mixture of
P+ Y Sugars,
100– R= I, approximate percentage of invert Sugar,
Oh! F
=percentage of invert sugar.
W
Polarimetry, Saccharimetry, and the Sugars 177
The factor, F, for calculating copper to invert sugar, is found in
table 84.
Eacample: The polarization of a sugar is 86.4, and 50 ml of solution containing
3.256 g of sample gave 0.290 g of copper.
Cu_0.290
2 2 = 0. 145 = Z.
4 × 100 n 145 sº 100. A 45 v
100P 8640
P+ Y 86.4 + 4.45
100—R = 100–95.1 = 4.9 = I.
R : I = 95.1 : 4.9.
By consulting the table, it will be seen that the vertical column headed 150 is
nearest to Z, 145, and the horizontal column headed 95:5 is nearest to the ratio
of R to I, 95.1:4.9. Where these columns meet there is found the factor 51.2,
which enters into the final calculation:
Cu F_0.290)×51.2
W T 3.256
= 95.1 = R.
= 4.56 percent of invert sugar.
(h) BROWN, MORRIS, AND MILLAR METHOD FOR REDUCING SUGAR IN MOLASSES [21]
The general method of these authors has been adapted by W. A.
Davis to the determination of reducing sugar in cane and beet molasses.
The method is extensively used in Great Britain. It is applied to
solutions containing 1 g of molasses in 100 ml (not defecated). The
Fehling solutions contain 34.639 g of copper sulfate crystals in 500 ml,
and 173 g of Rochelle salt and 65 g of sodium hydroxide in 500 ml,
respectively. Mix 25 ml of each of the two solutions in a 250-ml
beaker of tall lipped form and heat in a gently boiling water bath for
6 minutes. Add 50 ml of the molasses solution (1 g in 100 ml), cover
the beaker, and continue the heating for 12 additional minutes.
Collect the cuprous oxide in a Gooch crucible, wash with 200 ml of
boiling water, and finally with alcohol. Dry and oxidize to copper
oxide by placing the Gooch crucible in a larger ordinary crucible in a
tilted position, heat gently at first, and finally strongly over a Teclu
burner (but not with a blast lamp). Correct the weight of copper
oxide for the quantity (usually less than 1 mg) obtained in a blank
determination.
For weights of copper oxide less than 0.245 g multiply the weight
of copper oxide by the factor 81.5 to obtain directly the percentage of
invert sugar in the sample. For weights greater than 0.245 g, use the
factors given in table 20.
TABLE 20.-Factors for calculating invert sugar from copper owide
º. r Factor ºº Factor
| g g
| 0.3430 82. 31 0.3546 84. 60
| . 2668 82.46 . 3764 85. 02
. .2898 82.82 . 3971 85. 62
.3121 83. 31 . 4177 86. 19
.3339 83.86 . 4376 86.84
| |
178 Circular of the National Bureau of Standards
3. DETERMINATION OF COPPER
(a) GENERAL
The estimation of copper in the cuprous oxide precipitate may be
accomplished gravimetrically or volumetrically. The gravimetric
methods, which consist in the weighing of the cuprous-oxide precipi-
tate either directly or after conversion to copper or cupric oxide, may
be employed only in case the precipitate is uncontaminated. Con-
tamination may be caused by the precipitation or inclusion of inorganic
or organic impurities in the sample. Such precipitation is more likely
to occur when cruder samples are analyzed.
Sherwood and Wiley [22] made an extended series of analyses of
pure and crude products, which, in table 21, is condensed by com-
puting the averages. Included in the table is the mean of a number
of analyses made by Hammond.
TABLE 21,–Comparison of methods for determining reduced copper
Reduced copper
Material Author
From From Iodo- | Reduced | Electro-
weight weight metric by lytic
of Cu2O of CuO €LF1C alcohol
- g g g Q g
Molasses residuum . . . . . . Sherwood and Wiley_ _ _ _ _ (). 31.76 (). 3023 0.2938 |_ _ _ _ _ . . . . . . . . . . . . .
Corn juice- - - - -- . . . . . . . . . . . . do . . . . . . . . . . . . . . . . . 3360 | . . . . . . . . . 3134 |- - - - . . . . . . . . . . . . . . .
Malt extract ------------|--...- do----- - - - - - - - - - - - - - - - - -- . 2858 || - - - - - - , 2638 |- - - . . . . . . . . . . . . . -- - - -
Beer------------------...------ do-----, ------------ . 0750 | . . . . . . . . - - .0750 - - - - - - - - | . . . . . . . . --
Molasses------- . . . . . . . . . . . . . . do . . . . . . . . . . . . . . . . . . 4628 - - - - - - - - - - . 4520 - - - - - - . . . . . . . . . - - -- - - - -
Pure dextrose. . . . . . . . . . ---do. . . . . . . . . . . . . . . . . . 2773 |- - - - - - - - - . 2773 |- - - - - - - - - - - - - - - - - - - -
Molasses------. ...] Hammond . . . . . . . . . . . . ---|----------|------... - -- - - - - - - - (), 2519 (), 2467
Pure dextrose . . . . . . . --| - - - - do -- . . - -- * * ~ * * * * * * * * * * * . 3791 ----------|---------- . .3780 , 3784
The data presented indicate that the iodometric and electrolytic
methods yield the true weights of reduced copper. It is evident at
Once that other methods yield correct results only with relatively
pure substances. Unfortunately, the materials selected for illustra-
tion are extremely crude products and do not permit judgment as to
what classes of materials can safely be analyzed gravimetrically.
Unquestionably there are many classes of commercial products
sufficiently free from impurities which may contaminate the copper
precipitate, but the analyst must exercise discretion in the selection
of a method of copper analysis. Inasmuch as some of the volumetric
methods are less time-consuming than the gravimetric methods,
the recommendation appears justified that each analyst select one
which best meets his requirements, leaving the gravimetric methods
for materials of unquestionable purity. The data in table 21 show
that the error of analysis due to contamination is greatly diminished
by ignition to cupric oxide, which is weighed directly or reduced to
copper. Inorganic contamination is not removed by this procedure.
(b) GRAVIMETRIC METHODS
Preparation of asbestos [11].-Digest the asbestos, which should be
of the amphibole variety, with hydrochloric acid (1+3) for 2 to 3
days. Wash free of acid, digest for a similar period with 10-percent
Sodium hydroxide solution, and then treat for a few hours with hot
Polarimetry, Saccharimetry, and the Sugars 179
alkaline tartrate solution (old alkaline tartrate solutions are suitable)
of the strength used in sugar determinations. Wash the asbestos
free from alkali, digest for several hours with nitric acid (1+3), and
after washing free from acid, shake with water into a fine pulp. In
preparing the Gooch crucible, make a film of asbestos 4-inch thick and
wash thoroughly with water to remove fine particles of asbestos. If
the precipitated cuprous oxide is to be weighed as such, wash the
crucible with 10 ml of alcohol, then with 10 ml of ether, dry for 30
minutes at 100° C, cool in a desiccator, and weigh. For the most
careful work, the analyst should assure himself that the weight of the
crucible remains constant, by pouring 100 ml of clear hot alkaline
Solution through it, washing, drying, and reweighing.
A more rapid and perhaps equally effective method developed by
Brewster and Phelps for the preparation of asbestos is described on
page 324.
Determination.—The gravimetric estimation of copper by direct
weighing of cuprous oxide has been described in detail on page 170.
To eliminate organic contamination of the copper precipitate, it may
be converted to cupric oxide. Ignite at red heat for 15 to 20 minutes,
preferably in a muffle or in such a manner as to avoid exposure of the
precipitate to hot reducing gases. Too intense heating must be
avoided. Cool in a desiccator and weigh rapidly, since cupric oxide
is hygroscopic. Multiply the weight of cupric oxide by 0.7989 to
obtain the weight of copper. For the most careful work the crucible
containing the asbestos should be heated previous to the filtration in
order to insure its constancy of weight during the analysis.
Because of the hygroscopic nature of cupric oxide, and to eliminate
the possible error arising from its incomplete oxidation, it is some-
times advisable to reduce the precipitate to metallic copper. This
can be effected readily by exposing the precipitate to a continuous
stream of hydrogen and at the same time heating gently with a
Bunsen flame until reduction is complete. Cool in a stream of hydro-
gen. This method is facilitated by use of a filtering tube constructed
of hard glass, the asbestos being supported by a perforated disk or
platinum cone. This tube permits the direct application of the flame
during reduction, whereas the Gooch crucibles must be supported in a
suitable glass chamber.
A convenient method of reduction to copper is in use by the United
States Customs Service (Treasury Decision 39350; 1922). The
method was devised in principle by Wedderburn [23].
Wash the cuprous oxide thoroughly with water at a temperature of
about 60°C, then with 10 ml of alcohol, and dry for 30 minutes in a
water oven at 100° C. Heat the crucible for 30 minutes over a
Bunsen burner. The precipitate is reduced to metallic copper in me-
thyl-alcohol vapors. This is done by placing about 100 ml of methyl
alcohol in a 400-ml beaker, and placing a triangular support in the
beaker so that the crucible is above the level of the alcohol. Heat the
covered beaker on a hot plate to boiling, remove the cover, and place
the hot Gooch crucible on the triangle. This ignites the alcohol
vapors. Immediately cover the beaker with a watch glass and allow
the Gooch to remain for about 3 minutes, remove, cool in a desiccator,
and weigh.
180 Circular of the National Bureau of Standards
(c) ELECTROLYTIC DEPOSITION FROM NITRIC ACID SOLUTION [24]
Upon completion of the copper reduction reaction, decant the hot
solution through an asbestos mat in a Gooch crucible and wash the
beaker and precipitate thoroughly with hot water. Transfer the
asbestos mat from the crucible to the beaker with a glass rod and
rinse the crucible with 14 ml of nitric acid (1+1), allowing the rinsings
to flow into the beaker. After the cuprous oxide is dissolved, dilute
to 100 ml, heat to boiling, and continue the boiling for about 5 minutes
to remove the oxides of nitrogen. Cool, filter, and dilute to 200 ml.
Add 1 drop of 0.1 N hydrochloric acid and mix thoroughly.
If extreme care is exercised to avoid spattering, the cuprous oxide
can be dissolved by allowing the nitric acid to flow down the walls of
the crucible. Keep the crucible covered as well as possible with a
small watch glass. Collect the filtrate in a 250-ml beaker and wash
the watch glass and the tip of the pipette with a jet of water. Con-
tinue as described above, beginning with “heat to boiling.”
For electrolysis use cylindrical electrodes of platinum gauze 1.5 and
2 inches, respectively, in diameter, and 1.75 inches in height, thor-
oughly cleaned, ignited, cooled in a desiccator, and weighed. Insert
the electrodes in the copper solution so that the surface of the cathode
clears the anode by at least 5 mm and both electrodes almost touch
the bottom of the beaker. Electrolyze with a current of 0.2 to 0.4
ampere until deposition is complete, usually overnight. Without
interrupting the current, slowly lower the beaker and at the same time
wash the electrodes with a stream of distilled water. Immediately
immerse the electrodes in another beaker of water, lower the beaker,
and break the current. Rinse the cathode with ethyl alcohol and
dry º a few minutes in an oven at 110° C. Cool in a desiccator and
Weign.
(d) THIOSULFATE METHOD
When potassium iodide is added to a cupric copper solution, cuprous
iodide is precipitated and iodine liberated according to the equation
Cutt-H2I--Cut-i-IT-H 1/2 I.
The reaction is reversible and has been shown by Bray and MacKay
[25] to obey the mass law within certain limits in dilute solutions. For
the purposes of titration the reversible reaction can be made to run to
completion in either direction by adjustment of conditions. Thus by
the removal of cupric ions in the form of a complex ion or by great
dilution the reaction can be made to run quantitatively from right to
left, while the presence of a large excess of iodide ions, together with
the removal of cuprous ions in the form of insoluble cuprous iodide,
causes the reaction to run quantitatively from left to right.
Shaffer and Hartmann (26) determined the positions of the equili-
bria and concluded that for the determination of cupric salts potassium
iodide must be added to give a final concentration of about 0.25 M
(4 to 5 g per 100 ml of solution). For the determination of cuprous
salts, the solution must be so diluted that the final concentration of
copper and of iodide does not exceed about 0.005 M each. Equivalent
to this dilution, which curtails the general usefulness of the method,
is the addition of potassium oxalate, which forms anions containing
both copper and oxalate. The cuprous titration can thus be made
conveniently without excessive dilution.
Polarimetry, Saccharimetry, and the Sugars 181
The principles established by Shaffer and Hartmann are the basis
of the cupric titration given in detail below. The cuprous titration
is generally made directly in the reaction mixture, and examples are
given in several of the special reducing-sugar methods described under
“volumetric processes” page 185. (See also Methods of Analysis of
AOAC [27].)
Reagent.—Standard thiosulfate solution.—Prepare a solution con-
taining 39 g of pure Na2S2O3.5HO2 in 1 liter. Weigh accurately 0.2
to 0.4 g of pure Cu and transfer to a 250-ml Erlenmeyer flask roughly
graduated by marks at 20-ml intervals. Dissolve the Cu in 5 ml of
a mixture of equal volumes of HNO3 and H2O, dilute to 20 or 30 ml,
boil to expel the red fumes, add a slight excess of strong Br water, and
boil until the Br is completely driven off. Cool, and add NaOH solu-
tion with agitation until a faint turbidity of Cu(OH)2 appears (about
7 ml of a 25-percent solution is required). Discharge the turbidity
with a few drops of acetic acid and add 2 drops in excess.
Prepare a solution of 42 g of KI in 100 ml of solution made very
slightly alkaline to prevent formation of HI and its oxidation.
It is essential for the thiosulfate titration that the concentration of
KI in the solution be carefully regulated. If the solution contains
less than 320 mg of Cu, 4.2 to 5 g of potassium iodode should have
been added at the completion of the titration for each 100 ml of total
solution. If greater quantities of Cu are present, the amount of KI
should be proportionately greater. The KI solution should be added
slowly from a burette, with constant agitation.
Observe the volume of the Cu solution and add 1 ml of KI solution
for each 10 ml of the solution undergoing titration. Titrate at Once
with the thiosulfate solution until the brown color becomes faint.
Again observe the volume and add an additional volume of KI to
make the required concentration, noting from the volume of the thio-
sulfate the approximate Cu content of the solution. Add sufficient
starch indicator to produce a marked blue coloration. Continue the
titration cautiously until the color changes toward the end to a faint
lilac. As the end point is approached, add the thiosulfate in fractions
of drops, allowing the precipitate to settle slightly after each addition.
One ml of thiosulfate solution equals about 10 mg of Cu.
Determination.—Wash the precipitated Cu2O, cover the Gooch
crucible with a watch glass, and dissolve the oxide by means of 5 ml
of HNO3(1-H1) directed under the watch glass with a pipette. Collect
the filtrate in a 250-ml Erlenmeyer flask roughly graduated by marks
at 20-ml intervals, and wash the watch glass and Gooch crucible free
from Cu. Proceed as directed under “Reagent,” beginning with
“boil to expel the red fumes.”
Foote and Vance [28] have studied the titration and have proposed
that an addition of 2 g of ammonium thiocyanate be made when the
tiration has proceeded nearly to the end point. In the usual procedure
the cuprous iodide is not white but slightly discolored, apparently
as a result of the adsorption of iodine. Because of the greater insolu-
bility of cuprous thiocyanate, the surface particles of cuprous iodide
are changed to thiocyanate, releasing the adsorbed iodine, which thus
consumes a slight additional volume of thiosulfate. The end point is
exceedingly sharp, the precipitate turning completely white. This
modification can be introduced into the procedure described above,
182 Circular of the National Bureau of Standards
provided both standardization and determination are conducted in
the same manner.
Foote and Vance performed the titration in the presence of 5 ml
of sulfuric acid and in the presence of the same reagent buffered by
3 g of ammonium acetate and obtained the same analytical results.
Even a small volume of nitric acid (1 ml) produced no measurable
deviation. In view of these results, it is probable that the procedure
given on page 181 could be materially simplified.
(e) PERMANGANATE METHOD
When cuprous oxide is dissolved in a ferric sulfate solution the latter
is reduced to ferrous sulfate and can be titrated with standard per-
manganate. The reduced copper can then be computed on the basis
of the stoichiometric relations. This method of determination of
reduced copper was originally proposed by Mohr [29], but has erron-
eously been attributed to Bertrand [16]. Mohr prescribed that the
ferric sulfate be dissolved in sulfuric acid, and this procedure was
adopted by Bertrand, who based his tables (see page 587) upon the
volume of permanganate consumed, instead of referring his sugar to
copper. Subsequently, it was discovered that the permanganate
volumes, when converted to copper, gave results which were invariably
about 1.4 percent too low, and many authors advocated a blanket
correction by this amount. Schoorl and Regenbogen [30] ascribed the
low results to the rapid oxidation of ferrous sulfate by air. The oxida-
tion is more rapid than is ordinarily the case with ferrous sulfate, but
in the presence of copper, which increases the rate of oxidation, and in
the presence of the asbestos, which carries finely subdivided air, the
amount of oxidation appears to be accounted for.
Schoorl and Regenbogen found that if the cuprous oxide was dis-
solved in neutral ferric sulfate, or better, ferric alum, before addition
of sulfuric acid, correct results were obtained. A brownish-red clear
solution is obtained in which the Fe2O3 apparently remains dissolved
in the form of a basic salt. The authors suggest that the following
reaction occurs:
Cu2O + 2Fe2 (SO4)3 —-2CuSO4–H 2FeSO4–H Fe2O3 + SO3.
Reagents.-Prepare a potassium permanganate solution, about
0.1573 N, containing 4.98 g per liter. After several days' aging,
filter through asbestos or sintered glass. Standardize by either of the
following methods.
(a) Transfer 0.35 g of sodium oxalate (dried at 103°C) [31] to a
600-ml beaker. Add 250 ml of sulfuric acid (5-H95) previously boiled
for 10 minutes and cooled to 27-E3°C. Stir until the oxalate is dis-
solved. Add 29 to 30 ml of permanganate solution at a rate of 25
to 35 ml per minute while stirring slowly. Let stand until the pink
color disappears (about 45 seconds). Heat to 55° to 60°C, and com-
plete the titration by adding permanangate solution until a faint pink
color persists for 30 seconds. Add the last 0.5 to 1 ml dropwise, allow-
ing each drop to become decolorized before the next is added. De-
termine the excess of solution (usually 0.03 to 0.05 ml) required to
impart a pink color to the same volume of acid boiled and cooled to
55° to 60°C.
In potentiometric titrations the correction is negligible if the end
point is approached slowly.
Polarimetry, Saccharimetry, and the Sugars 183
(b) Transfer [32] about 0.3 g of As2O3 (dried at 110°C) to a 400-ml
beaker. Add 10 ml of a cool solution of sodium hydroxide (20 percent)
and allow to stand until dissolved, stirring occasionally. Add 100
ml of water, 10 ml of HCl (sp gr 1.18), and 1 drop of 0.0025 M KIOs
or KI. Titrate with permanangate solution until a faint pink color
persists for 30 seconds, adding dropwise the last 1 to 1.5 ml, and
allowing each drop to become decolorized before adding the next.
Determine by a blank test with all reagents except As2O3, the volume
of KMnO, (usually about 0.03 ml) required to duplicate the pink
color of the end point. The end point can also be determined with
ferrous phenanthroline indicator, in which case 1 drop of a 0.025 M so-
lution of the indicator is added as the end point is approached. De-
termine blank correction.
The titration can also be conducted potentiometrically.
Ferric sulfate.—Dissolve 135 g of ferric ammonium alum or 55 g of
Fe2(SO4)3 (anhydrous) and dilute to 1 liter. Determine Fe3(SO4)3
in the stock supply by strong ignition to Fe2O3. Ferric sulfate,
particularly after exposure to light, contains a small quantity of re-
ducing substance which must be oxidized before the solution is used.
Titrate 50 ml of the ferric sulfate solution, acidified with 20 ml of
4 N sulfuric acid, with the permanganate and use the titer as a zero-
point correction in subsequent titrations.
4 N sulfuric acid.
Ferrous phenanthroline indicator.—Dissolve 0.7425 g of orthophenan-
throline monohydrate in 25 ml of 0.025 M ferric sulfate solution (6.95
g of FeSO4.7H2O in 1 liter).
Procedure.—Filter the cuprous oxide in a Gooch crucible and wash
the beaker and precipitate thoroughly. Transfer the asbestos film
to the beaker with the aid of a glass rod. Add 50 ml of the ferric
sulfate solution and stir vigorously until the cuprous oxide is com-
pletely dissolved. Examine for complete solution, holding the beaker
above the level of the eye. Add 20 ml of 4 N sulfuric acid and titrate
with standard permanganate. As the end point is approached, add 1
drop of ferrous phenathroline indicator. At the end point the
brownish solution changes to green. One milliliter of 0.1573 N
permanganate equals 10 mg of copper.
The concentration of the permanganate solution in the method
described above is such that a single filling of the burette supplies
enough reagent for the determination of the maximum amount of
copper precipitated by any of the usual methods of analysis. For
many purposes the reagent is too concentrated. Thus, for the Small
quantities of copper precipitated by high-grade cane- or beet-sugar
Samples, a N/30 permanganate solution is more commonly used. An
Outstanding disadvantage of the method is that the larger weights of
cuprous oxide dissolve with great difficulty in the ferric sulfate solution.
(f) DICHROMATE METHODS
(1) ELECTROMETRIC.—Jackson and Mathews [33] have described a
rapid and convenient method for the determination of reduced copper,
in which cuprous oxide is oxidized in hydrochloric acid solution by an
excess of standard dichromate, the excess being determined by back
titration with ferrous sulfate to an electrometric end point. The
electrometric apparatus can be obtained by purchase or it may be
184 Circular of the National Bureau of Standards
assembled easily. Its arrangement is shown diagrammatically in
figure 38. The current from two dry cells, E, flows continuously
through a resistance, R, of about 3,000 ohms. The potassium
chloride bridge, C, of a calomel celland a bare platinum wire, P, dip into
the solution undergoing analysis. The sliding contact on the rheostat
is so adjusted as to produce a zero reading on the galvanometer, G,
when the electrodes dip into an acidified ferrous-ferric system con-
taining a slight excess of dichromate. As ferrous sulfate is added,
there is but slight change in the position of the galvanometer needle
until the end point is reached. At

the end point the deflection of the
== needle is so large that no actual
S. - measurements of electromotive force
are required. The galvanometer
—- E must be fairly sensitive.
Reagents.-Potassium dichro-
mate.—Dissolve 7,7135 g of pure
C crystals, preferably pulverized and
dried at 150° C, and make to a
volume of 1 liter. One milliliter of
this solution, which is 0.1573 N, is
FIGURE 38–Apparatus for electro- equivalent to 10.00 mg of copper.
tº
R
metric determination of copper. Ferrous ammonium sulfate.—Dis-
solve 61.8 g of the hexahydrate
crystals, add 5 ml of sulfuric acid, and make up to 1 liter. Equally
suitable is 43.8 g of FeSO4.7H2O, acidified and made to 1 liter. The
ferrous solutions are oxidized slowly by air and must occasionally be
titrated against the standard dichromate solution.
Procedure.—Collect the precipitated cuprous oxide on a Gooch
crucible and wash thoroughly. Detach the mat with a glass rod and
transfer to the reaction beaker. Add a small volume of water and
disintegrate the mat. Pipette accurately a volume of standard dichro-
mate in excess of the quantity required to oxidize the cuprous oxide.
In general, the approximate weight of copper will be known or can be
roughly estimated, but in any case a sufficient volume must be added to
supply an assured excess. Add from a graduated cylinder 50 ml of
1+1 hydrochloric acid with stirring, and continue to stir until all
cuprous oxide is dissolved. Immerse the crucible in the solution and
be sure that the adhering cuprous oxide is dissolved. Remove the
crucible with the glass rod, washing it free of solution. Dilute the
solution to about 250 ml and titrate the excess dichromate with ferrous
sulfate to an electrometric end point. Determine the ratio of ferrous
sulfate to dichromate, and thence compute the volume of dichromate
required for the oxidation of cuprous oxide. This volume multiplied
by 10 gives directly the number of milligrams of copper reduced.
(2) Color IMETRIC.—Many laboratories lack the necessary equip-
ment for electrometric titration, but a number of suitable internal
indicators are known which make possible a colorimetric end point.
A particularly serviceable one, orthophenanthroline,” was shown by
Walden, Hammett, and Chapman [34] to be applicable in oxidation-
reduction reactions.
Jackson and McDonald [35] have applied the colorimetric dichromate
method of titration to the determination of copper in cuprous oxide.
10 Manufactured by the G. Frederick Smith Chemical Co., Columbus, Ohio.
Polarimetry, Saccharimetry, and the Sugars 185
Reagents.-Potassium dichromate.—Standard solution, 0.1573 N,
containing 7.7135 g of pure dry crystals in 1 liter. One milliliter is
equivalent to 10 mg of copper. Ferrous ammonium sulfate.—Dissolve
61.9 g of the hexahydrate, add 5 ml of sulfuric acid, and complete the
volume to 1 liter. Hydrochloric acid.—Approximately 6 N. Phe-
manthroline-ferrous compler.—Dissolve 0.725 g of orthophenanthroline
monohydrate in 25 ml of 0.025M ferrous sulfate solution (6.95 g of
FeSO4·7H2O in 1 liter).
Procedure.—Estimate the volumes of hydrochloric acid and water
which at the end of the titration will yield a concentration of HCl of
about 2 N in about 200 ml of final volume. An error of from 5 to 10
percent can be tolerated.
Collect the precipitated cuprous oxide on a Gooch crucible and wash
thoroughly. Detach the mat with a glass rod and transfer to the
reaction beaker. Add a small volume of water and disintegrate the
mat. Pipette accurately a volume of standard dichromate in excess
of the quantity required to oxidize the cuprous oxide. In general,
the approximate weight of copper will be known or can be roughly
estimated, but in any case a sufficient volume must be added to supply
an assured excess. Add rapidly the whole required volume of hydro-
chloric acid with continuous stirring and continue to stir until all
cuprous oxide is dissolved. Immerse the crucible in the solution and
be assured that the adhering cuprous oxide is dissolved. Remove the
crucible with the glass rod and wash it with the water from the
graduate. Add 1 drop of phenanthroline solution and titrate with
ferrous sulfate to the permanent appearance of the brown ferrous-
phenanthroline complex. As the end point is approached, the brown
color appears and fades as each of the last few drops is added. The
ferrous sulfate must be added until the color is permanent, the
additions finally being in fractions of drops.
Determine the ratio of concentrations of ferrous sulfate and dichro-
mate and then compute the volume of dichromate required for the
Oxidation of cuprous oxide. This volume multiplied by 10 gives
directly the number of milligrams of copper reduced.
The electrometric and colorimetric dichromate methods described
above are still in an experimental stage in the laboratories of this
Bureau. A comparison has been made of the values of copper re-
duced by the Munson and Walker method and determined by the
thiosulfate and by colorimetric dichromate titration, respectively.
At low concentrations of copper, identical values were obtained by
the two methods. Above 200 mg of copper, systematic differences
occurred, which rose to a maximum of 0.2 percent for levulose and 0.3
percent for invert sugar. This discrepancy would disappear if a
special table were used for the dichromate methods. Further studies
are in progress, since the methods recommend themselves on account
of their great rapidity and convenience.
4. VOLUMETRIC METHODS
(a) LANE AND EYNON METHOD
The most convenient, most expeditious, and frequently the most
accurate method for the determination of reducing sugars is the volu-
metric method of Lane and Eynon [36]. In principle, the method
involves the determination of the volume of sugar solution required
186 Circular of the National Bureau of Standards
to reduce completely a measured volume of alkaline copper solution,
the end point being internally indicated by the reduction of methylene
blue to methylene white by a minute excess of reducing sugar. Methy-
lene blue is a thiazine dye, intensely colored and of oxidation reduction
potential well suited to the titration of reducing sugars. A few
drops of a 1-percent solution of this dye impart an intense blue
color to the reaction mixture, which, in the absence of air, is al-
most instantly reduced to the leuco base by an excess of reducing
sugar. The methylene white is rapidly reoxidized by air, particularly
at the high alkalinity of the reaction mixture. Hence it is essential
that air be excluded during the titration. This is accomplished by
causing an uninterrupted current of steam to issue from the neck of
the flask in which the analysis is performed.
Lane and Eynon determined the weight of each sugar required to
reduce the copper completely. These weights, which vary with
the nature of the sugar and with its concentration, constitute a table
of factors (tables 85 and 86), from which the proper one may be
selected when the titer is known. The concentration of sugars is
then
Factor X 100 •
--Titºr--mg of sugar in 100 ml.
(1) STANDARD METHOD of TITRATION.—Ten or twenty-five milli-
liters of mixed Soxhlet reagent is measured into a flask of 300- to 400-ml
capacity, and treated cold with almost the whole of the sugar Solution
required to effect reduction of all the copper, so that if possible not
more than 1 ml is required later to complete the titration. The
approximate volume of the sugar solutions required is ascertained by
a preliminary incremental titration. The flask containing the cold
mixture is heated over an asbestos-gauze plate. After the liquid has
begun to boil, it is kept in moderate ebullition for 2 minutes, and then,
without removal of the flame, 3 to 5 drops of the methylene blue indi-
cator are added, and the titration is completed in 1 additional minute,
so that the reaction liquid boils altogether for about 3 minutes with-
out interruption.
The visual end point coincides with the disappearance of cupric
ions and hence is the same as that marked by the ferrocyanide and
the electrometric test. It has the advantage over the ferrocyanide
test that the search for the end point can be completed without in-
terruption of the titration.
Like all volumetric reducing-sugar methods, this method produces
best results if almost all the sugar required is added in the early
stages of the analysis. Usually the sugar concentration is not known
with sufficient certainty to do this. Consequently, Lane and Eynon
advise performing a preliminary titration in order to determine the
approximate volume of solution required. This is most conveniently
accomplished by adding an initial volume of 15 ml of the sugar
Solution to the measured volume of copper solution, boiling for about
15 to 20 seconds, and then adding further increments of sugar until
the blue color of the copper solution has nearly disappeared. This
point can be fairly judged within 1 or 2 ml of sugar solution. At this
point the methylene blue is added and the titration completed drop-
wise, the period of operation occupying as nearly 3 minutes as possible.
Polarimetry, Saccharimetry, and the Sugars 187
In the analysis of solutions of the hexoses, this incremental method
is nearly as reliable as the standard method, but with solutions of
the disaccharides and solutions containing sucrose, it is desirable to
repeat the titration by the standard method.
The outlet of the burette should be fitted with a rubber tube
connected with a glass tube bent twice at right angles in order that
the solution shall not be heated by the reaction mixture. Glass
stopcocks cannot be used as they invariably jam under the fluctuating
temperature conditions.
Soxhlet's modification of Fehling's solution is used for the method.
The solution is made by mixing exactly equal volumes of (1) a copper
sulfate solution containing 69.28 g of CuSO4.5H2O per liter, (2) a
solution containing 346 g of Rochelle salt and 100 g of sodium hydrox-
ide per liter.
Pure copper sulfate ordinarily contains somewhat more than the
theoretical amount of water. Hence the authors recommend that a
standardization of the solution be performed by titration against a
standard invert-sugar solution and that any small adjustment of
the copper solution be made to correspond with the tables by addition
of copper sulfate or water. Twenty-five milliliters of solution (1)
should contain 440.9 mg of copper.
The standard solution of invert sugar may be prepared as follows:
A solution of 9.5 g of pure sucrose is treated with 5 ml of hydrochloric
acid (sp gr 1.19), made up to about 100 ml, left at room temperature
for several days (e.g., about 1 week at 12° to 15°C or 3 days at 20° to
25° C) and then made up to 1 liter. The acidified 1-percent solution
of invert sugar is very stable and retains its titer unchanged for
months. A known volume of the standard solution is neutralized
with sodium hydroxide and suitably diluted immediately prior to use.
The experimental factor determined by titration, of the standard
solution is
Titer Xmg of sugar per 100 m!_F,
100 te
F' is then compared with F, the tabulated factor, and the copper
solution is adjusted accordingly. If the deviation of the experimental
from the tabulated factor is small, it has been the practice of this
Bureau to apply the small correction to the tabulated factors rather
than to make numerous adjustments of the copper Solution.
Carry out the titration as described, find in the table the factor
corresponding to the titer and, if necessary, apply to the factor the
correction previously determined. Estimate the sugar by
Factor X 100
Titer
The Lane and Eynon factors are given in tables 85 and 86, pages
590–91.
(2) APPLICATIONS OF THE METHOD.
Determination of reducing sugars in raw sugars containing more than
about 0.4 percent of reducing sugars.-A solution of the sample con-
taining 5, 10, or 25 g per 100 ml is titrated against 10 ml of Fehling
Solution, the percentage of reducing sugar (as invert sugar) being
found from table 85. Preliminary treatment with normal lead ace-
=mg of sugar in 100 ml.
188 Circular of the National Bureau of Standards
tate and potassium oxalate is generally unnecessary except for very
low-grade raw sugars.
The sucrose content may be found from the invert-sugar content
before and after hydrolysis, which is carried out as described below.
Determination of reducing sugars in refined or raw sugars containing
less than about 0.4 percent of reducing sugars.-Twenty-five grams of
the sample is dissolved with a quantity of neutralized standard invert-
sugar Solution containing 0.1 g of invert sugar, and the whole is made
up to 100 ml. A convenient procedure is to wash 25 g of the sample
into a 100-ml flask containing the requisite quantity of neutralized
invert-sugar Solution. After solution and completion to volume, the
solution is titrated against 10 ml of Fehling solution. The percentage
of invert sugar in the sample is found by deducting 0.1 from the per-
centage of invert Sugar in the solution and multiplying the remainder
by 4, or it may be found directly from table 87, page 592.
Determination of invert sugar in molasses.—If the sucrose in the
sample is to be determined polarimetrically, it is convenient to weigh
65 g of the sample and dilute to 250 ml, using 50 or 100 ml of this
solution for determination of reducing sugars, as described below.
Came molasses.—A solution containing 13 g of the sample is treated
with 25 ml of a 10-percent solution of normal lead acetate, made up
to 250 ml, shaken and filtered. Fifty milliliters of the filtrate is
treated with 5 ml of a 10-percent solution of potassium oxalate, a
little alumina cream is added, and the solution is made up to 250 ml,
shaken, and filtered. The filtrate, which is free from lead and calcium
salts, represents a 1.04-percent solution of the sample and is titrated
against 10 ml of Fehling solution. The percentage of invert sugar in
the sample is found from table 85 by interpolation between the values
given in the columns headed “no sucrose” and “1 g of sucrose per
100 ml.’’
NOTE.-For purposes of interpolation, a 1.04-percent solution of cane molasses
may be taken as containing 0.3 percent of sucrose.
Beet molasses.—One hundred milliliters of a solution of the sample
(26 g in 100 ml) is treated with 30 ml of a 10-percent solution of
normal lead acetate, shaken, and filtered. The filtrate, representing
a solution of the sample of 20 g in 100 ml, is treated with enough solid
potassium oxalate (e. g., about 2 g) to remove lead and calcium and
filtered. The filtrate is titrated against 10 ml of Fehling solution,
the percentage of invert sugar in the sample being found from table
85, column headed “10 g of sucrose per 100 ml.” If the sample con-
tains more than 1 to 1.5 percent of invert sugar, the deleaded and
decalcified solution should be further diluted with distilled water
before titration.
NOTE.-A 20-g sample of beet molasses may be taken as containing 10 g of
SUICI'OSe.
Determination of sucrose in came or beet molasses.—Fifty milliliters
of the clarified, deleaded, and decalcified 1.04-percent solution of cane
molasses obtained as above is treated with 15 ml of 1.0 N hydrochloric
acid, diluted to about 150 ml, heated to boiling, and kept boiling for 2
minutes. The solution is then cooled, neutralized with sodium hydrox-
ide, and made up to 200 ml. The solution, which now represents a
0.26-percent solution of the sample, may be titrated against 10 ml of
Fehling solution, the invert-sugar content being found from table 85,
Polarimetry, Saccharimetry, and the Sugars 189
column headed “no sucrose.” The sucrose content of the sample is
calculated from the difference between the invert-sugar content
before and after hydrolysis. Sucrose in beet molasses may be deter-
mined by a similar method.
Determination of reducing Sugars in starch, dextrin, and glucose.—
For most purposes it is sufficient to assume that the reducing sugars in
starch dextrin and starch sugar consist of dextrose. This is determined
by titrating a solution of the sample of suitable concentration against
10 or 25 ml of Fehling solution and finding the dextrose content of
the solution from table 85 or 86.
If it is desired to determine dextrose and maltose in starch products,
the procedure devised by Morris [37] may be used.
Determination of lactose in Sweetened condensed milk.-In the analysis
of Sweetened condensed milk, the determination of lactose by Fehling
Solution is somewhat affected by the sucrose present. The effect of
the sucrose is to reduce the volume of lactose solution required, and it
may be allowed for by adding the requisite correction to the burette
reading. Tables 85 and 86 give the values for lactose itself, and table
88 shows the burette corrections, in milliliters, for sucrose-lactose
ratios of 3:1 and 6:1. At any given part of table 88 the correction is
practically proportional to the sucrose-lactose ratio, and the propor-
tionality holds up to a ratio of about 10:1.
(b) SCALES METHOD
(1) GENERAL.-Scales [38] devised an iodometric semimicro
method of analysis which requires the use of samples of less than 20
mg of monosaccharides or less than 30 mg of diaccharides. The entire
analysis is conducted in a single reaction vessel. Scales confined his
experimental analyses to dextrose and concluded that each milliliter
of iodine represented a constant weight of sugar irrespective of the
concentration. He prescribed a 3-minute period of boiling over a
free flame or an electric hot plate.
Isbell, Pigman, and Frush [39] employed a modification of the method
for determining the reducing powers of a wide variety of sugars.
They found that greater precision of analysis was obtained if the period
of boiling was increased to 6 minutes. Shaffer and Somogyi (see p. 169)
showed that relatively large differences in reaction rates occurred
between certain sugars. Hence in order that a uniform method of
analysis might be adopted, the time of reaction must be adapted to
the most slowly reacting sugar. If the rapidly reacting sugars,
dextrose and levulose, are analyzed, it is suitable to shorten the period
of boiling to the 3 minutes prescribed by Scales.
Isbell, Pigman, and Frush were unable to verify Scales' statement
that each milliliter of iodine represented a constant weight of glucose,
irrespective of the concentration of sugar, but found the function
f= 1.05.11+0.0021C+0.000086C*,
in which f is the factor for glucose and C is the titer in milliliters of
0.04 Niodine. The factors for glucose are shown in tables 22 and 23.
The various sugars under strictly comparable conditions reduce
different quantities of copper. It may be observed by comparing the
reducing values given in table 24 that epimeric sugars give approxi-
323414°—42—14
190 Circular of the National Bureau of Standards
TABLE 22.-Factors for calculating glucose by the Scales method
• * - e. Sugar factors | Calculated from
DextroSe |0.04 N iodine (average) equation
7ng Tml
5 4. 69 1. 067 1. 063
10 9. 30 1. 0.75 1. 078
15 13. 72 1. 093 1.096
20 17. 92 1. 116 1. 116
25 21.93 1. 140 1. 139
mately like reducing values—that is, the configuration of carbon 2
does not materially influence the reducing power. The similarity of
epimeric sugars probably arises from the rapidity with which they
revert to the common enolic form. Since the groups about carbons
3, 4, and 5 are held more firmly, sugars which differ in the configura-
tion of these carbons are not interconvertible in the alkaline solution
and exhibit characteristic properties. Sugars in which the hydroxyl
on carbon 3 is trans to the hydroxyls on carbons 4 and 5 give the
highest reducing powers, while sugars which have cis hydroxyls on
carbons 3 and 4 give lower reducing values. The differences in the
values for lactose, maltose, cellobiose, and turanose show that the
configuration of the nonreducing component in the disaccharide
molecule influences the reducing power and that the reducing power
of the disaccharide may be higher or lower than that of the reducing
sugar component. If the glycosidic union is on carbon 3, as in tura-
nose, the molecular reducing power is less than that of the corre-
sponding monosaccharide. If the glycosidic union is on carbon 4,
the molecular reducing power is about 1.4 that of the corresponding
monosaccharide; and if the glycosidic union is on carbon 6, the molecu-
TABLE 23.−Factors for various sugars for use with the modified Scales method 1
Milligrams of anhydrous Milligrams of anhydrous
Sugar per milliter of 0.04 Sugar per milliter of 0.04
M-iodine N-iodine
Sugar Sugar
5-ml | 10-ml | 15-ml | 20-ml 5-ml | 10-ml | 15-ml | 20-ml
titer | titer | titer | titer titer | titer | titer | titer
l-Arabinose----------- 1.078 | 1.092 | 1. 107 | 1. 127 || Lactose - - - - - - - - - - - - - - 1.426 | 1.434 | 1.445 | 1.462
Cellobiose------------|------- 1. 383 | 1.393 | 1.413 || Lactulose- - - - - - - - - - - - 1.460 | 1.467 | 1.477 |_ _ _ _ _ _
d-Fructose- - - --------| 1.040 | 1.050 | 1.078 || 1.097 || d-Lyxose -- - - - - - - - - - - - - - - - - - - 0.994 | 1.006 | 1.024
!-Fucose--------------|------- 1.201 | 1. 235 |_ _ _ _ _ _ _ Maltose-------------- 1.479 | 1.481 | 1.485 | 1.497
d-Galactose----------- 1. 215 1. 223 | 1. 240 | 1.267 || d-o-Mannoheptose- - - - - - - - - - 1. 310 | 1.328 - - - -
d-o-Galaheptose------|------- 1.261 | 1. 292 |_ _ _ _ _ _ _ d-6-Mannoheptose----|------- 1. 312 | 1.329 |_ _ _ _ _ _
d-6-Galaheptose------|------- 1. 259 | 1. 283 |_ _ _ _ _ _ _ d-Mannose----------- 1.075 | 1.087 | 1. 103 || 1, 126
Gentiobiose----------|------- 1. 717 | 1. 731 | 1. 755 || Melibiose . . 1. 747 | 1. 757 | 1.769 |_ _ _ _ _ _
d-or-Glucoheptose-----|------- 1. 291 | 1.313 |_ _ _ _ _ _ _ Neolactose----------- 1.427 | 1.433 | 1.440 | 1.451
d-6-Glucoheptose-----|------- 1. 318 | 1.341 |_ _ _ _ _ _ _ l-Rhamnose.---------|------- 0.973 || 0.999 |_ _ _ _ _ _
d-Glucoheptulose-----|------- 1. 287 | 1. 322 |_ _ _ _ _ _ _ d-Ribose - - - ---------- 1.049 | 1.065 | 1.083 | 1. 106
d-Glucose------------ 1.067 | 1.075 | 1.093 | 1. 116 || l-SorboSe_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1. 171 | 1. 182 |_ _ _ _ _ _
4-8-Glucosido-man- d-Talose--------------|------- 1. 224 | 1. 240 |------
DOS8----------------|-------|------- 1. 360 | 1.392 || Turanose-------------|------- 2. 691 || 2.714
d-or-Guloheptose------|------- 1. 291 | 1.312 |_ _ _ _ _ _ _ d-Xylose------------- 0.996 || 1.007 | 1. 021 | 1. 040
d-6-Guloheptose------|------- 1. 318 | 1.341 |_ _ _ _ _ _ _ Invert Sugar---------- 1.061 | 1.067 | 1.082 | 1.095
d-Gulose-------------|------- 1. 152 | 1. 170 |_ _ _ _ _ _ _
! The factors given in this table are the averages of the values obtained in measurements conducted in this
laboratory over a period of 8 years. Each value represents not less than 3 determinations. The individual
determinations by the same operator did not vary over 1 percent, but the results of different operators
Varied by as much as 2 percent.
Polarimetry, Saccharimetry, and the Sugars
191
TABLE 24.—Relative molecular reducing power' (modified Scales method)
- 0.04 N Relative
aßis iodine molecular
Sugar - sugar in Solution reducing
10 ml consumed power:
by Cu2O glucose=1
Tng 7ml
d-Glucose------------------------------- 15 13. 7 1.00
d-Mannose------------------------------ 15 13. 6 0.99
d-Fructose------------------------------ 15 13.9 1.01
l-Rhamnose----------------------------- 13. 7 13.8 1. 01
d-Galactose----------------------------- 15 12.2 0.89
d-Talose-------------------------------- 15 12.2 . 89
!-Fucose-------------------------------- 13. 7 11.4 . 83
d-Gulose-------------------------------- 15 12.9 .94
l-Sorbose-------------------------------- 15 12.8 .93
l-Arabinose----------------------------- 12.5 11.4 . 83
!-Ribose-------------------------------- 12. 5 11. 7 . 85
d-Ribose-------------------------------. 12.5 11. 7 . 85
d-Xylose-------------------------------- 12, 5 12.4 .91
d-Lyxose-------------------------------- 12.5 12.6 . 92
d-o-Galaheptose------------------------- 17. 5 13.6 . 99
d-6-Galaheptose------------------------- 17. 5 13. 7 1. 00
d-or-Glucoheptose----------------------- 17. 5 13. 6 0.99
d-6-Glucoheptose------------------------ 17. 5 13. 1 .96
d-Glucoheptulose----------------------- 17. 5 13. 3 . 97
d-or-Mannoheptose------------------ - - - - 17. 5 13.2 .96
d-8-Mannoheptose---------------------- 17. 5 13. 2 .96
d-or-Guloheptose------------------------ 17. 5 13.4 98
d-8-Guloheptose------------------------- 17. 5 13. 1 .96
4-6-Glucosido-mannose------------------ 28. 5 20.4 1.49
4-6-Glucosido-glucose (cellobiose).-------- 28. 5 20. 2 1.47
4-o'-Glucosido-glucose (maltose).--------- 28, 5 19. 1 1. 39
4-6-Galactosido-glucose (lactose).--------- 28. 5 19. 5 1.42
4-6-Galactosido-fructose (lactulose).------ 28, 5 19. 1 1. 39
4-6-Galactosido-altrose (neolactose).------ 28. 5 19.7 1.44
6-8-Glucosido-glucose (gentiobiose).------ 28. 5 16.4 1, 20
6-of-Galactosido-glucose (melibiose).------ 28. 5 ]6. I 1. 18
3-o-Glucosido-fructose (turanose).-------- 28. 5 10.6 (). 77
! Ratio of the reducing power of the Sugar to the reducing power of glucose.
lar reducing power is about 1.2 that of the corresponding mono-
saccharide. It may be observed from the results given in table 25 that
the molecular reducing powers of the pentoses are slightly lower and
of the heptoses slightly higher than the molecular reducing powers
of the corresponding hexoses.
TABLE 25.-Molecular reducing power for configurationally related substances
Configuration 1 | Average molecular reducing power
C2 C3 C3 C3 PentOSes HexOSes HeptoSeS
+ — — — — — 0.91 1.00 1. 00
— — —H + . 92 . 99 . 99
+ — — —H· 83 . 89 .96
— — — — — 85 . 89 .96
+ + — — — -------- .94 .99
— — — — —H | -------- || -------- .96
| The configurations of carbons 2, 3, 4, and 5 are indicated by plus and minus signs according to whether
the OH lies to the right or left when the formula is written in the conventional manner. For example, the
configuration of d-glucose is indicated by + — + +. In the case of the pentoses, the sugar has been classified
with the configurationally related hexose. Thus d-xylose, d-lyxose, l-arabinose, and l-ribose are placed with
groups having the (+) configuration for carbon 5.
192 Circular of the National Bureau of Standards
(2) METHOD FOR MAKING SUGAR DETERMINATIONs.
Reagents.--(1) Dissolve 16 g of copper sulfate (CuSO4.5H2O) in
125 to 150 ml of water. Dissolve sodium citrate, 150 g of 2Na3Ca（O.
11H2O or 124 g of Na3CsPI;O.2H2O; 130 g of anhydrous sodium
carbonate; and 10 g of sodium bicarbonate in about 650 ml of water,
while warming them slightly to accelerate solution. Cool and com-
bine the two solutions while stirring, make up to 1 liter, and filter.
& § 0.04 N solution of iodine containing 4 percent of potassium
IOCI1016.
(3) 0.04 N sodium thiosulfate solution containing 0.1 g of sodium
carbonate.
(4) Hydrochloric acid solution containing 60 ml of concentrated
HCl per liter.
| (5) Acetic acid solution containing 24 ml of glacial acetic acid per
iter.
Procedure.—To 10 ml of a solution containing 10 to 20 mg of a
monosaccharide (or about 30 mg of a disaccharide) and contained in a
300 ml Erlenmeyer flask, add from a fast-draining pipette 20 ml of
the copper reagent. Stopper the flask with a two-hole rubber stopper
and place over an electric heater or gas flame so regulated that the
solution comes to boil in 4 + 4 minutes. Allow the solution to boil for
6 minutes and then cool it in an ice-water bath for $4 minute while
keeping the solution in gentle circular motion. Remove the flask
from the ice-water bath, draw up 25 ml of 0.04 N iodine solution into
a pipette, and while holding the pipette, pour into the flask from a
graduate 100 ml of the acetic acid solution, mix gently, and add the
iodine solution from the pipette. Then pour 25 ml of the hydrochloric
acid solution down the walls of the flask and into the solution. Mix
with a gentle circular motion and titrate the excess iodine with 0.04
N sodium thiosulfate, using starch as the indicator. Subtract the
back titration from the iodine originally added and multiply this value
by the sugar factor to give the milligrams of sugar in the sample.
For best results each worker should determine his own factors by
applying the method to known quantities of sugars. If a large num-
ber of determinations is to be made, charts in which the factors are
plotted against the titrations may be constructed so that the factor
for any titration may be obtained readily.
(c) SCHOORL METHOD FOR INVERT SUGAR IN CANE MOLASSES [40]
Solutions.—Soxhlet solution, p. 170. Deleading solution. Dissolve
7 g of Na2HPO4.12H2O and 3 g of K2C2O4.H2O and make to 100 ml.
Procedure.—Dissolve 6 g of molasses in water in a 250-ml volu-
metric flask and defecate with 15 ml of a 10-percent neutral lead acetate
solution. Make to volume and filter. Transfer 50 ml of the filtrate
to a 100-ml flask and add 5 ml of deleading solution. Make to volume
and filter. Pipette 50 ml of the filtrate containing 0.6 g of molasses
into a 300-ml Erlenmeyer flask and add accurately 50 ml of Soxhlet
reagent. Add one or two fragments of washed and ignited pumice,
and place the flask on a wire gauze resting on an asbestos card with a
central hole 6.5 cm in diameter. Heat to boiling in 4 minutes and
continue the boiling for exactly 2 minutes. Cool rapidly without
agitation and add 25 ml of KI solution (20 g in 100 ml) and 35 ml of
H2SO4 (1 volume of concentrated acid to 5 volumes of water). Titrate
Polarimetry, Sacchari metry, and the Sugars 193
the liberated iodine with 0.1 N thiosulfate, using 3 to 4 ml of a 1-per-
cent starch solution as indicator. Determine the blank titration,
using 50 ml of water instead of the sugar solution. Deduct the titer
of the test sample from that of the blank, and multiply the result by
6.357 to obtain the number of milligrams of copper reduced. Refer
the weight of copper to table 96, p. 602, and read the percentage of
invert Sugar. The table is applicable only to a 0.6-g sample of molasses.
A linear interpolation yields accurate results.
(d) METHODS FOR SMALL PERCENTAGES OF INVERT SUGAR IN SUCROSE
(1) OFNER METHOD [41].-(Official method of the Czechoslovakian
Republic.)
Reagent.—Dissolve 5.0 g of CuSO4.5H2O, 10.0 g of anhydrous
Na2CO3, 300 g of pulverized Rochelle salt, and 50 g of Na2HPO4.12H2O
in about 900 ml of water at room temperature, warming slightly at
the end of the solution, if necessary. When completely dissolved,
it is advisable to heat for 2 hours on the water bath to destroy mold
spores. Cool and fill to 1 liter. Treat with active carbon or kieselguhr
and filter. Preserve the solution in a dark place.
Sodium thiosulfate.—Dissolve 4.00 g of crystals and make to a
volume of 500 ml or, preferably, prepare a stock solution containing
in 500 ml, 20.0 g of crystals and 1 ml of N NaOH or 0.1 g of Na2CO3.
Dilute 100 ml to 500 ml, as required. Standardize in the usual way
or titrate against the following iodine solution.
Iodine solution.—Dissolve 2.05 g of pure iodine in about 10 g of
iodate-free KI dissolved in a few milliliters of water. Make to a
volume of 500 ml and preserve in a dark place.
Starch solution.—Rub 2.5 g of soluble starch and about 10 mg of
red mercuric iodide in a little water. Dissolve the starch in about
500 ml of boiling water.
Approacimately N hydrochloric acid.
Sodium phosphate solution.—Dissolve 100 g of Na2HPO4.12H2O
and make to 1 liter. (For lead precipitation.)
Neutral lead acetate.—Dissolve 250 g of Pb(C2H5O)2.3H2O and
fill to 1 liter.
Procedure. Refined or affined sugars.-Dissolve 20 g of the sample
in distilled water and make up to 100 ml. Transfer 50 ml of the
Solution to a 300-ml Erlenmeyer flask and add 50 ml of the copper
Solution. Mix well, add a knife point of pumice or talcum powder,
and set on a wire gauze resting on an asbestos card having a central
hole 6.5 cm in diameter. Heat to boiling with a Bunsen flame within
4 to 5 minutes and continue the boiling for exactly 5 minutes, diminish-
ing the flame so that only the tip touches the gauze. Cool without
agitation by immersion in cold water. Pour from a graduated
cylinder 15 ml of 1.0 N hydrochloric acid down the wall of the flask,
and add immediately a carefully measured volume of the iodine
solution (burette or calibrated pipette). The volume of iodine will
vary from 5 to 20 ml, according to the amount of copper reduced, but
must always be added in excess. After the first few milliliters of
iodine have flowed in, the remainder must be added with continuous
agitation. Stopper the flask and allow the iodine to react for 2
minutes with occasional agitation. Add 5 ml of the starch solution
and titrate the excess of iodine with thiosulfate. Deduct the volume
194 Circular of the National Bureau of Standards
of the excess iodine from the volume added. One milliliter of iodine
solution is equivalent to 1 mg of invert sugar. Ten grams of pure
sucrose have, under the conditions of analysis, a reducing power
equivalent to 1 ml of iodine; hence deduct 1 ml from the volume of
iodine required in the test for reoxidation of the copper. In general,
deduct 0.1 ml of iodine for each gram of sucrose in the sample.
Pure sugar sirups.-Prepare a solution containing a known weight
of dry substance, preferably 7 to 10 g in 50 ml.
Raw sugar.—Transfer 52 g of the sample to a 200-ml volumetric
flask. Dissolve in water, add 2 to 3 ml of neutral lead acetate.
Make to volume and filter. Transfer 153.6 ml to a 200-ml flask and
add 15 ml of sodium phosphate solution and make to volume. Add
1 g of active carbon, mix thoroughly and allow to stand 15 minutes.
Filter and take 50 ml (10 g) of the filtrate for analysis. For the copper
analysis take 20 ml of iodine. If the sample contains more than 0.15
percent of invert sugar, take 25 ml (5 g) for analysis. Deduct 0.1 ml
from the volume of iodine for each gram of sucrose in the sample.
More impure after-products.-Dissolve 52 g in water, add 4 to 5 ml
of lead acetate, fill to 200 ml, and filter. Pipette 153.6 ml into a
200-ml flask, add 20 ml of sodium phosphate solution, make to 200 ml,
mix, and filter. Add 1 g of active carbon, mix thoroughly, and allow
to stand for 15 minutes. Filter and take for analysis 50 ml or some
smaller volume that will contain not more than 15 mg of invert sugar.
Molasses and low-purity sirups.—Dissolve 26 g in water, add 10 ml
of neutral lead acetate, fill to 200 ml, mix, and filter. Transfer 153.6
ml of the filtrate to a 200-ml volumetric flask, add 20 ml of sodium
phosphate solution, fill to volume, mix, and filter. Add 4 g of active
carbon, agitate thoroughly, allow to stand 15 minutes, and filter.
Take 50 ml (5 g) of molasses for analysis. Conduct the analysis as
described above, but continue the boiling for 7 instead of 5 minutes,
since the impurities in low-grade products diminish the rate of reduc-
tion of copper. Since 5 g of molasses contains about 2.5 g of sucrose,
deduct 0.25 ml from the iodine volume.
Low-grade products frequently contain substances, notably SO,
which are oxidized by iodine. Ofner, therefore, recommends a
“cold” experiment in which the analysis is carried out as described
above but with the omission of the boiling period. The iodine
consumed in the cold analysis, together with the correction for sucrose,
is deducted from the total iodine consumed in the analysis.
(2) SPENGLER, TöDT, AND SCHEUER METHOD [42].
Preparation of stock Müller's solution.—Dissolve 35 g of CuSO4.5H2O
in 400 ml of boiling water and in a separate container 173 g of Rochelle
salt and 68 g of anhydrous Na2CO3 in 500 ml of boiling water. Allow
both solutions to cool and pour the second solution into the first with
agitation. Add 1 to 2 teaspoonfuls of active carbon and after several
hours' standing, filter with suction through a hardened filter paper.
If copper compounds separate subsequently, the solution must be
refiltered.
Procedure.—Transfer 100 ml of a solution containing 10 g of sugar
to a 300-ml Erlenmeyer flask, add 10 ml of the stock Müller solution,
and heat for 10 minutes in a boiling-water bath. The bath must be
heated so strongly that the introduction of the flask does not interrupt
the boiling. Adjust the position of the flask so that the level of the
Polarimetry, Saccharimetry, and the Sugars 195
inner liquid surface is at least 2 cm below the outer. Cool rapidly to
about room temperature without agitation and add 5 ml of 5 N
acetic or tartaric acid and then 20 or 40 ml of 0.0333 Niodine solution.
After the precipitated cuprous oxide is completely dissolved, titrate
the excess of iodine with 0.0333 N thiosulfate, using a few milliliters of
1- to 2-percent starch solution as indicator.
Conduct a blank analysis with 100 ml of water in the same manner.
Deduct the thiosulfate titer of the sugar analysis from the blank
titer to determine the volume of 0.0333 N iodine used for reoxidation
of the precipitated copper. One millititer of 0.0333 N iodine equals
1 mg. of invert sugar.
When a series of analyses is conducted, it is obviously necessary to
determine the blank only occasionally.
The stability of the thiosulfate solution is increased by the addition
of about 3 ml of normal sodium hydroxide per liter of solution.
A deduction of 2 ml of 0.0333 Niodine (equals 2 mg of invert sugar)
is made to correct for the reducing power of 10 g of pure sucrose and,
in general, in the same proportion for smaller weights of sample, for
example, for 2.5 g of sucrose a deduction of 0.5 ml is made.
The authors recommend for many cases a “cold analysis,” which is
conducted in the manner described above except that the heating is
omitted. This permits a correction for such impurities as sulfites,
which otherwise would be reported as invert sugar.
Ten milliliters of Müller solution contains sufficient copper to
oxidize 40 mg of invert sugar, but the authors recommend that
samples be taken containing not over 30 mg. Thus if the invert sugar
is in excess of 0.3 percent, a correspondingly smaller sample should
be taken. -
(3) LUFF-SCHOORL METHOD [43].-(For determination of invert
Sugar in cane sugars ranging from 0.3 to 4.0 percent.)
Preparation of copper solution.—Dissolve with gentle heating
17.3 g of CuSO4.5H2O and 115 g of citric-acid crystals in about 200
ml of water in a 1-liter volumetric flask. To this solution, after
cooling, add with agitation 185.3 g of anhydrous Na2CO3 in about
500 ml of water. It is important that the second solution be added to
the first and not the first to the second. Make to 1 liter, shake well
with 2 g of washed and ignited kieselguhr, and filter with suction.
The total alkalinity should be 1.78 N (phenolphthalein) and should
be controlled.
Procedure.—Transfer to a 300-ml Erlenmeyer flask, 25 ml of the
copper reagent and 25 ml of the sugar solution containing 5 g of the
sample, or, if necessary, such smaller quantity as contains not more
than 45 mg of invert sugar. Add a few fragments of pumice, and
place the flask on a wire gauze resting on an asbestos card having a
central hole 6.5 cm in diameter. Fit the flask with a reflux air con-
denser, heat to boiling in 3 minutes, and continue the boiling for
exactly 5 minutes. Cool at once without agitation in tap water.
To the cooled solution add 15 ml of KI solution (20 g in 100 ml) and
15 ml of H2SO, (25 g of concentrated acid in 100 ml,) in such a manner
as to avoid loss by effervescence. Titrate the liberated iodine with
0.1 N thiosulfate, using about 1 ml of a 1-percent starch solution as
indicator. Make a blank determination, using 25 ml of water in
place of the sugar solution. Refer the difference between the volume
of 0.1 N thiosulfate required by the blank and the sample under test
196 Circular of the National Bureau of Standards
to table 97, p. 602, to ascertain the corresponding weight of invert
sugar in the sample.
Standardization of thiosulfate.—Dissolve 25.5 g of Na2S2O3.5H2O
#. "; g of Na2CO3 and make to 1 liter. Standardize with pure
2UI'2"U7.
Weigh accurately about 0.22 g of K2Cr,0; and dissolve in 450 ml
of water in a 750-ml Erlenmeyer flask. Add successively 15 ml of
RI solution (20 g in 100 ml) and 15 ml of concentrated HCl. Titrate
the liberated iodine with thiosulfate, using 3 ml of a 1-percent starch
solution as indicator.
mg K2Cr2O7
49.022×ml thiosulfate
5. MICROCHEMICAL METHODS
(a) SOMOGYI MODIFICATION OF SHAFFER AND HARTMANN MICROMETHOD FOR
DEXTROSE
Normality factor=
Shaffer and Hartmann [44] elaborated in detail a method for the
determination of sugar in blood, which was applicable to the analysis
of samples containing from 0.07 to 2.2 mg of reducing sugar. The
method was subsequently applied to other materials than blood and
indeed has been found generally applicable to any material containing
reducing sugar. It is particularly serviceable in instances in which
it is necessary to conserve the supply of material.
Shaffer and Hartmann copper reagent was prepared by mixing
copper sulfate, tartaric acid, and sodium carbonate, the last two
substances reacting and releasing carbon dioxide. The solution also
contained potassium iodate and potassium iodide in such concentra-
tion that it was 0.02 N with respect to iodine which was released upon
acidification.
Somogyi [8], in a study of the method, found that the amount of
copper reduced was in a high degree dependent upon the alkalinity
of the solution. Within a narrow range, in which the ratio of Na2CO3
to NaHCO3 lay between 7:13 and 2:3 and the pH varied from 9.40
to 9.55, the highest copper values were obtained and the ratio of copper
to sugar remained constant. In the Shaffer and Hartmann solution
the ratio of carbonate to the bicarbonate formed by the reaction of
tartaric acid with sodium carbonate was variable and depended upon
the variable amount of carbon dioxide lost. Somogyi therefore
modified the Shaffer and Hartmann solution.
Reagents.
Grams
Final per
concentration Substance liter
0.026 M__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Copper sulfate crystals--- - - - - - - - - - - - - - - - - - - 6.5
.06 M----------------- Rochelle salt------------------------------ 12
2 M------------------ Sodium carbonate (anhydrous)-- - - - - - - - - - - - - 20
3 M------------------ Sodium bicarbonate------------ - - - - - - - - - - - - 25
.023 N 12- - - - - - - - - - - - - - Potassium iodide-------------------------- 10
Potassium iodate-------------------------- . 80
.1 M------------------ Potassium oxalate------------------------- 18
Dissolve the Rochelle salt, sodium carbonate, and sodium bicar-
bonate in about 500 ml of water, and into this pour with stirring the
copper sulfate dissolved in about 100 ml of water; then add the
solution of the other constituents and dilute to 1 liter. (Only the
potassium iodate need be weighed accurately.)
Polarimetry, Saccharimetry, and the Sugars 197
Measure 5 ml of the reagent into a large test tube (250 by 25 mm)
and add 5 ml of the sugar solution containing not less than 0.1 mg
and not more than 2.0 mg of dextrose. Mix by gentle shaking, cover
the tube with a small funnel, bottle cap, or glass bulb, and keep it
in a boiling-water bath for 15 minutes. Cool by placing in a shallow
dish of water until the temperature is lowered to 35° or 40° C. Add
with agitation 1 ml of 5 N H2SO4 (or its equivalent) and see that all
Cu2O is promptly dissolved. After about 2 minutes, titrate with 0.005
N sodium thiosulfate. A blank titration on 5 ml of the reagent is
determined after heating with an equal volume of water.
The difference between the blank and the titration of a determina-
tion is equivalent to the copper reduced and thus to the sugar. The
corresponding amounts of sugar are given in table 98, p. 603, which
is a modified form of the table given in the original article.
Notes.—Details of the determination of sugar in 0.2 ml of blood are given in the
reference cited.
A 0.005 N thiosulfate solution cannot be kept unchanged for more than a few
days. It is advisable to keep a 0.1 N stock solution and prepare 1:20 dilutions as
required.
Any agitation of the test tubes, from the beginning of heating in the water bath
up to the addition of acid, should be avoided to minimize reoxidation of cuprous
oxide by air.
It is undesirable to cool below 30° C. If the sample contains more than 1 mg
of Sugar, incomplete oxidation of copper may occur.
In order that the pH of the reagent may remain unaltered, it is important that
the sample be neutralized with sodium hydroxide (not carbonate). Phenol red
i º ºble indicator and renders the end point of the thiosulfate titration more
1STUII). CTG.
(b) BENEDICT MODIFICATION OF FOLIN AND WU METHOD [46, 47)
Reagents.-Alkaline copper solution.—Dissolve 200 g of sodium
citrate and 60 g of sodium carbonate in about 800 ml of water. Then
dissolve 6.5 g of pure copper sulfate crystals in about 100 ml of water
and add to the former solution with agitation. Add 9 g of ammonium
chloride, dilute to 1 liter, and mix.
Tungstic acid color.—Dissolve 100 g of pure sodium tungstate in
about 600 ml of water in a liter flask. Add 50 g of pure arsenic
pentoxide, then 25 ml of 85-percent phosphoric acid and 20 ml of
concentrated hydrochloric acid. Boil 20 minutes. After cooling
this, add 60 ml of commercial formalin, 45 ml of concentrated hydro-
chloric acid, and 40 g of sodium chloride. Dilute to 1 liter and mix.
To 100 ml of the alkaline copper solution add 2.5 to 3.0 g of pure
anhydrous sodium sulfite and preserve for use. This solution is not
reliable after 1 month.
Procedure.—Transfer 2 ml of the sugar solution and 2 ml of the
copper reagent to a Folin and Wu sugar tube. Into another tube
transfer 2 ml of a standard dextrose solution containing 0.1 (or 0.2)
mg per milliliter and 2 ml of copper reagent. Mix by side-to-side
shaking and place the two tubes in boiling water for 5 mintues. Cool
by immersion in cold water and add to each 2 ml of tungstic acid color
reagent. After 1 to 2 minutes dilute to 25 ml, mix thoroughly, and
compare in a colorimeter. The sugar in the unknown solution is
calculated by the formula
Depth of column of standard
Depth of column of unknown
X10 (or 20)=mg per 100 ml.
198 Circular of the National Bureau of Standards
(c) FERRICYANIDE MICROMETHOD OF HAGEDORN AND JENSEN
Hagedorn and Jensen [48] devised a method particularly for the
determination of blood sugar, but which is capable of extension to the
analysis of any material containing minute quantities of reducing
sugar. The maximum weight of dextrose which can be determined
is 0.385 mg.
When ferricyanide in alkaline solution is heated with a reducing
sugar it is reduced to ferrocyanide, the amount of reduction being a
measure of the amount of sugar taken. The quantity of reduced
ferricyanide is determined as the difference between the total and that
remaining after the reduction reaction. The determination depends
upon the reaction
2HaRe(CN)6+2HI=2H4Fe(CN)6+I,
which is reversible but can be made to run quantitatively from left to
right by the precipitation of ferrocyanide as a zinc complex:
2K, Fe(CN)6+3ZnSO4=KAZn3(Fe(CN)6]2+3K2SO4.
The liberated iodine is then titrated with standard thiosulfate.
The Hagedorn-Jensen method has been used extensively in blood
analysis. It is introduced into this circular because of its probable
general applicability to other materials than blood. It has the great
advantage that ferrocyanide is stable in air and no back oxidation
occurs. Miller and Van Slyke [49] point out the disadvantage of the
determination of ferrocyanide by difference, and they describe a
method of direct titration with ceric sulfate, the end point being
determined in the presence of the indicator, Setopaline C (a trade
name). However, ceric sulfate gave uncertain results with fructose,
which curtails the general applicability of the modification. Shaffer
and Williams [50] have described a modification in which the amount
of reduction is determined by measuring the potential of the ferri-
ferrocyanide electrode. This is extremely rapid and convenient, but
is to be recommended only if the number of analyses is great enough
to justify the labor of assembling the necessary apparatus. Van
Slyke and Hawkins [51], using the Van Slyke-Neil apparatus [52],
determined unreduced ferricyanide gasometrically by measuring the
pressure of nitrogen evolved by the reaction
4KaRe(CN)6+N2H4+4Na(OH=4|K&NaFe(CN)6+4H2O+N2
and have shown that the method can be used rapidly and conveniently
for the determination of sugar in both blood and urine. Folin [53]
determined the ferrocyanide by a colorimetric measurement of the
prussian blue found by addition of ferric chloride to the reaction mix-
ture after completion of the reduction. He also described an effec-
tive method for the purification of ferricyanide. Hawkins [54], using
the gasometric method, found that the reduction was proportional to
concentration for all sugars analyzed except fructose, arabinose, and
xylose, in which instances it was proportional up to 0.1-mg concen-
tration. The relative reducing powers are glucose, 1.00; mannose,
1.014; galactose, 0.792; fructose, 0.986; arabinose, 0.949; xylose,
1.019; maltose, 0.725; and lactose, 0.726.
Reagents.--(1) Dissolve 1.65 g of KaRe(CN)6, recrystallized and
dried at 50°C, and 10.6 g of anhydrous Na2CO3. Fill to 1 liter and
preserve in the dark.
Polarimetry, Saccharimetry, and the Sugars 199
(2) ZnSO4.7H2O, 10 g; NaCl, 50 g; and water to 200 ml. Im-
mediately before use, add solid KI in the proportion of 2.5 g per 100
ml to the volume of solution required for the analyses. If added to
the stock solution, a separation of iodine occurs with lapse of time.
(3) Acetic acid, 3 ml of glacial acid in 100 ml.
(4) One gram of soluble starch in 100 ml of saturated NaCl solution.
(5) Sodium thiosulfate 0.005 N. Dissolve 0.7 g of crystals and
make to 500 ml. Standardize frequently by titration against 0.005
N KIOA (0.3566 g in 2 liters), adding for each 10 ml of iodate solution
about 20 mg of KI and a few milliliters of dilute HCl,
Procedure.—Into large test tubes (30 by 90 mm) transfer a sugar
Solution containing less than 0.38 mg of dextrose, and add water to
make a volume of 12 ml. Add accurately 2 ml of the alkaline ferri-
cyanide Solution and heat in a boiling-water bath for 15 minutes.
Cool and add 3 ml of the potassium-iodide-zinc-sulfate solution and
2 ml of acetic acid. Titrate the liberated iodine, using a microburette
and 2 drops of starch indicator.
Conduct a blank determination in the absence of sugar. Refer to
table 99, p. 604.
Eacample.—A sample of sugar required 1.26 ml of thiosulfate, and the blank,
1.86 ml; 2.00 ml of standard iodate required 1.90 ml of thiosulfate. Each titer
is multiplied by 2.00/1.90 to reduce it to a 0.005 N basis. Corrected titers are,
respectively, 1.33 and 1.95 ml. In table 99, 1.33 ml is equivalent to 0.119 mg,
º ": ml to 0.008 mg of dextrose. Therefore, the corrected sugar content is
6. COLORIMETRIC AND VISUAL METHODS
(a) POT METHOD OF MAIN FOR DETERMINATION OF REDUCING SUGARS IN RAW
SUGARS AND SIMILAR PRODUCTS [55]
Main has devised a visual method for the determination of reducing
sugars, which is capable of yielding results of high precision and of
extending the range of quantitative estimation to very low per-
centages. The reaction is carried out in large resistant-glass test
tubes, 150-mm length by 38-mm internal diameter and weighing 50
to 55 g. In order to avoid back oxidation by air, a series of floats is
constructed of similar test tubes having slightly smaller diameter and
which make a sliding fit into the others. The barrels of these floats
are 100 mm long, and the upper end of each is drawn out to a taper,
making a total length of about 170 mm.
The water bath is an ordinary oval iron kitchen pot, tinned inside,
the capacity of which is 3 gallons. An overflow is fitted near the
upper edge of the boiler, and hot water is added continuously through
a “sight feed” to replace loss by evaporation. The temperature of
the water must be maintained at the boiling point, for which a large
ring gas burner is necessary. While in the water bath, the tubes are
supported symmetrically by clips in a carrier.
Two alkaline copper reagents are employed: solution I, for concen-
trations of invert sugar extending up to 16 percent; solution II, for
samples containing a maximum of 0.832 percent.
Solution I.-The usual Soxhlet modification of Fehling solution
(p. 170). 10 ml of the mixed reagents are used for the analysis. The
results are referred to in table 100, p. 605.
Solution II.-A Soxhlet solution (A) as usual, containing 34.639
g of CuSO4.5H2O in 500 ml of Soxhlet solution; (B) 173 g of Rochelle
200 Circular of the National Bureau of Standards
salt, 50 g of NaOH, and 14.647 g of K.Re(CN)6 in 500 ml of solution.
For solution II, mix 1 volume of (A), 1 volume of (B), and 2 volumes
of 5 N NaOH. This mixed reagent was designated “L. F. S.”, and
the results are referred to in table 101.
In the extra-alkaline L.F.S. solution, the ferrocyanide, which is
present in the ratio of 1 mole to 4 moles of cupric sulfate, has the
function of combining with the reduced copper to form cuprous ferro-
cyanide and obviates the red coloration that tends to mask the end
point as indicated by the methylene blue.
For the standardization of copper solution I, invert sugar is prepared
according to the method of Lane and Eynon [36]. Prepare a stand-
ard invert-sugar solution by dissolving 9.5 g of pure sucrose, accu-
rately weighed, in about 80 ml of water, adding 5.3 ml of hydrochloric
acid (sp gr 1.16, or approximately 10 N), and completing the volume
to approximately 100 ml. Allow this solution to stand at 22° to 25°C
for 3 or 4 days and dilute to 1 liter. From this stock solution, pipette
50 ml into a 250-ml flask, neutralize with sodium hydroxide (approxi-
mately 2.5 ml of N NaOH), and complete to volume. This solution
now contains 0.002 g of invert sugar per milliliter.
Transfer the following solutions to each of three tubes in the order
stated: 10 ml of mixed Soxhlet solution (solution I); standard neutral-
ized invert-sugar solution, 24.5, 25.0, and 25.5 ml, respectively; and
2 drops of 1-percent methylene blue.
Mix the contents of each tube by gentle rotation and insert the
floats so that they rest on the liquid, care being taken not to entrap
any air bubbles. Place the tubes in the carrier and immerse in the
briskly boiling water for exactly 5 minutes. Then remove and
inspect. In general, one of the three solutions will show complete
reduction of copper, while the adjacent one will show a trace of blue.
The volume of invert intermediate between these two is taken as
equivalent to 10 ml of Soxhlet solution. The precision of standardiza-
tion and also of analysis can be greatly increased by lessening the
intervals between the volumes in the tubes. The mean between
the last blue and the first red is always taken as the true result, unless
the blue color is actually seen to fade in a tube on removing it
from the pot at the end of the 5 minutes. In such case, the actual
volume in that tube is taken as the correct figure.
As in other methods, some preliminary idea of the amount of invert
sugar present in the sample must be ascertained by using a rough
incremental titration or other guide.
For the estimation of small percentages of invert sugar, that is,
less than 0.8 percent, L. F. S. solution (solution II) may be used. The
table upon which the use of this solution is based overlaps table 100
for solution I, since the latter permits the estimation down to about
0.3 percent. The L. F. S. solution should be standardized against
an invert-sugar solution containing 0.025 g per 100 ml; 37 ml of such
a solution should decolorize 4 ml of L. F. S. in the presence of 2 drops
of methylene blue.
The time of heating for amounts of invert sugar below 0.01 percent
must be increased to 10 minutes, as shown in table 101, p. 606.
Polarimetry, Saccharimetry, and the Sugars 201
(b) DE WHALLEY METHOD FOR THE DETERMINATION OF INVERT SUGAR IN
REFINED WHITE SUGARS [56]
Range, 0.001 to 0.015 percent, capable of extension to higher per-
centages by dilution with pure sucrose.
Select test tubes of white glass 6 by % inches having a uniform weight
of about 9.4 to 9.6 g. Fit large rubber rings about the tops in order to
Support them in the water bath. The bath is of sheet copper, 7-inch
cube with three holes 1 inch in diameter, the central hole being used
for the test and the other two as steam vents. A constant water
level is maintained 2 inches below the top of the bath. Heat is
applied by a ring burner protected from draught. For accurate work,
maintain a constant gas pressure of 3.5 to 3.75 inches of water by
means of a pressure regulator.
Prepare accurately solutions of, (1) 0.20-percent methylene blue
and (2) 3 N sodium hydroxide.
Grind the sample of sugar and transfer 7 g, weighed correctly within
0.05 g, to a clean, dry test tube. Add 6 ml of distilled water, 1 ml. of
methylene blue (microburette or calibrated pipette), and 1 ml of the
caustic soda solution.
Shake the test tube (closed with a rubber stopper) vigorously for
15 seconds, and immerse in the boiling water bath for exactly 2
minutes. Remove from the bath and compare immediately with
the row of standard tubes.
Standards.-Prepare a solution of 19.5 g of CuSO4.5H2O in boiled
distilled water and make to 500 ml. Measure accurately the following
volumes into 50-ml volumetric flasks and add to each 10 ml of am-
monium hydroxide (sp gr 0.880; 32.9 percent of ammonium hydroxide
by titration) and make to volume. *
TABLE 26.-Standards for use with the de Whalley method
Invert-Sugar º Invert-Sugar º
Standard sulfate Standard *J le
Solution Solution
Percent 7ml Percent 7ml
(). 001 40.00 0.007 2.97
. 002 24. 60 . 008 2. 26
. 003 16. 40 . 009 1. 74
, 004 10. 66 . 010 1. 33
, 005 7. 18 . 015 0. 50
. 006 4.92 | - - - - - - - - - -
7. ELECTROMETRIC METHOD FOR THE DETERMINATION OF
REDUCING SUGARS [57, 58]
When a solution of reducing sugar is added to a boiling alkaline
copper solution, the potential set up at a platinum electrode during
the first part of the titration is represented by the expression
RT Cut
Ept- Ecu"—scu"- TF log}}
The concentration of cupric ions is governed by the composition of
the alkaline tartrate solution and by the removal of copper in the
form of insoluble cuprous oxide. The concentration of cuprous ions
is determined by the solubility product of cuprous hydroxide. When
202 Circular of the National Bureau of Standards
all the cupric ions have been removed the potential changes rapidly.
This sudden change in potential indicates the end of the reaction
between cupric ions and reducing sugar.
A micro application of the electrometric method has been made by
Niederl and Müller [59]. They used alkaline copper solutions com-
posed of (A) 3.95 g of CuSO4.5H2O in 500 ml of solution; (B) 19.75 g
of Rochelle salt and 7.4 g of NaOH in 500 ml of solution. For the
analysis, they mixed equal volumes of A and B. Their apparatus
consisted of two vessels, each containing an alkaline copper solution
of the same concentration, in which was immersed a platinum elec-
trode. The vessels were connected by an agar-potassium chloride
bridge.
†. analysis, 3 to 5 mg of substance is accurately weighed, dissolved
in water (1 ml for each mg), and transferred to a microburette.
One milliliter of the mixed copper reagent, containing 1 mg of copper
is placed in each of the two vessels. A reading is taken on the potenti-
ometer and again after the solution in one vessel is brought to boiling.
A preliminary titration is carried out as follows: 0.1 ml of the Sugar
solution is added, the mixture boiled, and a reading taken again.
Additions of the sugar solution are continued until 1.2 ml has been
used. In the region of the end point the change of potential is very
considerable. The maximum change per 0.01 ml marks the end
point. The actual determination is carried out in the same way, but
larger volumes of the sugar solution are used until the end point is
approached.
Their results are as follows:
Sugar equivalents of 1 mg of copper
7ng
d-Glucose------------------------------------- 0. 635
d-Mannose------------------------------------ . 638
d–Galactose----------------------------------- . 770
d-Fructose------------------------------------ . 679
Maltose-------------------------------------- 1. 019
Lactose--------------------------------------- 0, 884
Invert sugar---------------------------------- . 657
The following method, in which the end point is determined by the
change of potential between two thick copper wires serving as elec-
trodes, has been devised by Tryller [60]:
Reagents and apparatus.--(1) Soxhlet solution (I), 34.639 g of
CuSO4.5H2O made to 500 ml of solution; (II), 173 g of Rochelle salt
and 50 g of NaOH made to 500 ml of solution.
(2) Sodium sulfate for cell, 39.415 g of anhydrous Na2SO4 made to 1
liter of solution.
(3) An electrode of thick copper wire (about 2 mm in diameter).
(4) A cell of Pyrex-glass tubing (8 mm inside diameter with a
plug (8 mm long) of plaster of paris at one end. The plug
should be washed with the cell solution in which it should
be stored when not in use.
(5) A dead-beat moving-coil galvanometer with central zero.
(6) A press-key.
(7) Burette stand, 250-ml Pyrex flasks, burettes, etc.
Method.—The arrangement consists of a galvanometer wired
directly to the electrodes through a press-key. Any convenient
Polarimetry, Saccharimetry, and the Sugars 203
number of flasks may be wired to the same galvanometer. Figure
39 shows the flask and electrode assembly. The 250-ml, flat-bottomed
flask is fitted with a cork (7) which holds the thick copper-wire
electrode, the tip of the burette (6), the cell (2), and the steam vent
(5) in position. A copper wire makes contact between the inner
cell and the lead to the galvanometer. The liquid in the inner cell
is composed of 5 ml of Soxhlet solution II, 5 ml of sodium sulfate
solution, and 40 ml of water. This solution may be made up and
stored for short periods of time, the liquid in the cell being changed
after every six determinations.
A plaster-of-paris plug lasts for 25 to 30 determinations, after
which time its sensitivity is reduced. The changing of the cell is
easily carried out by making the
hole for the cell a sliding fit and
placing the rubber collar (9)
around the top and adjusting it
so that the plug is immersed to
a suitable depth. With this ar-
rangement, the cell may be
changed while waiting for the
solution to boil. A perforated
asbestos slab resting on the
shoulder of the flask deflects
the hot gases away from the
measuring apparatus.
In carrying out the determina-
tion, the method of Lane and
Eynon is followed to the point
where methylene blue is added.
At this time the press-key is de- , , &
pressed; and, if the galvanometer Fº jº', for electrometric
needle is deflected, the Sugar solu- | cº º º ºntº.
tion is added dropwise. The "of paris plug. 5, steam vent; 6, burette tip; , cork;
tº 8, asbestos; and 9, rubbor collar.
swing of the needle becomes less
and less until finally 1 drop will cause a deflection in the opposite
direction. Toward the end of the titration it is advisable to wait 3
to 5 seconds between the addition of 1 drop of sugar solution and the
next, as at this point there appears to be a slight lag before the system
attains equilibrium. . .
8. SELECTIVE METHODS
(a) JACKSON AND MATHEWS MODIFICATION OF NYNS METHOD FOR LEVULOSE
Elaborating an observation made by Biourge [61], that at 50° C
levulose had, in the presence of Ost reagent, a reducing power 10
times as great as that of dextrose, Nyns [62] determined the copper-
levulose equivalents over a wide range of sugar concentrations by
heating the reaction mixtures at 48.6°C for 2% hours. Jackson and
Mathews [63] modified the Nyns procedure, shortening the time of
reaction by raising the temperature to 55° C and specifying an in-
creased concentration of copper, thus enlarging the range of sugar
concentrations which could be analyzed and supplying more rapid
methods of copper analysis.

204 Circular of the National Bureau of Standards
(1) STANDARD SoLUTIONs—
Potassium dichromate.—Prepare a standard solution N × 0.1573,
by dissolving 7.7135 g of the pure dry salt and filling to 1 liter. One
milliliter is equivalent to 10.00 mg of copper.
Ferrous ammonium sulfate.—Dissolve 61.8 g of the hexahydrate,
º ; ml of concentrated sulfuric acid, and complete to a volume
of 1 liter.
Ost solution.—Dissolve 250 g of potassium carbonate (anhydrous)
in about 700 ml of hot water and add 100 g of pulverized potassium
bicarbonate. Agitate until completely dissolved. Cool and add,
with very vigorous agitation, a solution of 25.3 g of pure CuSO4.5H2O
in 100 to 150 ml of water. Adjust to room temperature, make to
1 liter, and filter.
(2) ANALYTICAL PROCEDURE.-Transfer 50 ml of Ost reagent to
a 150-ml Erlenmeyer flask. Add by means of an accurately graduated
pipette a volume of the solution to be analyzed. This should contain
not more than 92 mg of levulose or its equivalent of a levulose-
dextrose mixture, remembering that dextrose has about one-twelfth
the reducing power of levulose. Add enough water to make the
total volume 70 ml. Immerse in a water bath regulated preferably
to within 0.1° C at 55° C. Digest for exactly 75 minutes, agitating
with a rotary motion at intervals of 10 or 15 minutes.
At the expiration of the prescribed time, filter the precipitated
copper on a closely packed Gooch crucible and wash the flask and
filter thoroughly without attempting to transfer the precipitate
quantitatively. (It is well, however, to transfer all of the loose cuprous
oxide, leaving in the flask only the small portion which adheres to the
walls.) Remove the asbestos mat by means of a glass rod and
transfer to a 400-ml beaker. Add 5 or 10 ml of water and disintegrate
the asbestos mat. Add a carefully measured volume of standard
potassium dichromate (NX 0.1573) in excess of the volume required
to oxidize the cuprous oxide. In many cases the expected amount
of precipitated copper will be roughly known, and it will be possible
to gage the volume of dichromate which will supply a 3- to 4-ml
excess. If the amount of precipitated copper is not even roughly
known, it is preferable to add an amount which will supply an assured
excess. A very large excess introduces no uncertainty, provided its
volume is accurately measured. Of this volume about 1 ml is added
to the original reaction flask in order that the residual cuprous oxide
may be dissolved and subsequently added to the remainder of the
solution. Add to the Erlenmeyer flask by means of a graduated
cylinder about 50 ml of hydrochloric acid (1+1). Pour the acidified
solution slowly into the 400-ml beaker with constant stirring, and
continue to stir until the cuprous oxide is completely dissolved. Wash
the Erlenmeyer flask with a jet from the wash bottle, receiving the
rinsings in the beaker. Examine the asbestos critically by looking
through the bottom of the beaker, which is held above the eye. . (If
any undissolved cuprous oxide remains, it can be clearly discerned as
dark-colored particles.) Immerse the crucible in the acidified solu-
tion to dissolve such cuprous oxide as remained in it. Remove the
crucible with a glass rod, washing it free of solution. Dilute the
solution thus prepared to about 250 ml and electrometrically titrate
the excess of dichromate with ferrous sulfate.
The excess of dichromate can also be determined satisfactorily
Polarimetry, Saccharimetry, and the Sugars 205
with the use of the internal indicator, orthophenanthroline, as described
on page 184. Indeed, any other method of copper analysis will serve
equally well, but in all cases control analyses with pure levulose
should be made and a correction applied to bring the copper equiva-
lents into correspondence with table 93, p. 597.
In table 93 is given the correspondence between the reduced copper
and the levulose in the sample.
(3) ANALYSIS OF DExTROSE-LEVULOSE MIXTURES.–Jackson and
Mathews found that the method, when applied to dextrose-levulose
mixtures, lacked perfect selectivity and that it was necessary to apply
a correction for the reducing power of dextrose. Throughout the
entire range of concentrations 12.4 mg of dextrose proved to have the
same reducing power as 1 mg of levulose.
For the analysis of an unknown mixture of dextrose and levulose
two equations are necessary for a solution, and Jackson and Mathews
recommended a combination of the Lane and Eynon titration for total
reducing sugar and the modified Nyns method. The Lane and Eynon
titration (25 ml of Soxhlet reagent) is corrected to correspond with
the Lane and Eynon table, as described on page 187, and multiplied
by the number of milligrams of “apparent” levulose, that is, the
levulose equivalent of the copper from table 93. The product,
divided by 100, is referred to table 94, p. 599 and the ratio of levulose
to total sugar is read from the appropriate column.
(b) HINTON AND MACARA METHOD FOR LEVULOSE IN CONDENSED MILK
Hinton and Macara [64] devised a method which they applied to
the determination of levulose in sweetened condensed milk, but which
obviously is capable of a more general application. In outline, the
method consists in the oxidation of aldose groups to aldonic acids,
leaving the levulose unaltered. The levulose is then determined by
reducing-sugar analysis. A control solution free of levulose is analyzed
simultaneously.
Reagents.-(1) Sucrose solution, approximately 9 g of sucrose per
100 ml (freshly prepared).
(2) Iodine solution, 13 g of iodine and 15 g of KI per 100 ml.
N ºſised alkaline solution, equal parts of 2 N Na2CO3 and 2 N
8,O_II.
(4) Sulfuric acid, approximately 5 N.
(5) Sodium sulfite solution, 20 percent by volume.
(6) Dilute sodium sulfite solution, 2 percent freshly prepared; or
diluted from 20-percent solution.
(7) Luff solution. Dissolve 25 g of CuSO4.5H2O in 100 ml of
water; 50 g of citric acid in 50 ml of water; 338 g of Na2CO3.10H2O
in 300 to 400 ml of lukewarm water. Add the citric acid solution
to the sodium carbonate solution, and then add the copper solution.
Mix, cool, make up to 1,000 ml and filter. This solution should be
accurately prepared, and 10 ml of the finished solution should require
approximately 45 ml of 0.5 N sulfuric acid for neutralization to methyl
Orange.
(8) Todate-iodide solution, 2.7 g of KIO4, 30 g of KI and 10 ml of
0.5 N, NaOH solution per liter.
(9) Potassium oxalate solution.
(10) Sodium thiosulfate solution, 0.05 N.
323414°–42—15
206 Circular of the National Bureau of Standards
(11) Soluble starch solution, approximately 2 percent.
(12) Control serum, prepared from fresh milk with the same
quantities of ammonia and acetic acid and precipitants as for 40 g
of condensed milk, made up to 200 ml and filtered.
Procedure 1, oridation of aldose sugars.—Pipette 10 ml of the con-
densed milk serum (zinc serum, page 207) and the same amount of
the control serum into 250-ml Erlenmeyer flasks in such a way that
the liquid does not flow on the sides of the flasks. To the condensed
milk serum add 10 ml of water, and to the control serum add 10 ml
of the sucrose solution. Add to each exactly 5 ml of the jodine solu-
tion and exactly 6 ml of the 2 N mixed alkali solution; mix gently,
and allow the flasks to stand for 10 minutes at from 18° to 20° C.
Acidify with 1.6 ml of 5 N sulfuric acid, and remove the liberated
iodine, first, with 20-percent sodium sulfite solution, and finally, after
adding 6 drops of starch solution, with the 2-percent sulfite solution.
This operation should be conducted as rapidly as possible and with
the precision of a titration, although the quantities of sulfite solution
need not be measured. When all of the free iodine is eliminated,
immediately add 1 drop of methyl orange solution and neutralize with
2 N mixed alkali solution. The time elapsing between acidifying with
5 N sulfuric acid and neutralizing with the mixed alkali should not
exceed 2 minutes to avoid the danger of inversion of the sucrose.
Procedure 2, treatment with Luff solution.—To the contents of each
flask add 20 ml of Luff solution; cover with a watch glass and heat
the contents to boiling on a plain wire gauze over a burner regulated
so that the boiling takes place in 2 minutes; impinging of the flame
as hot gases on the sides of the flask should be prevented by an as-
bestos sheet, with a central hole of suitable dimensions, placed in
contact with the wire gauze. When boiling takes place, transfer the
flask to an asbestos-covered gauze already heated by a small Bunsen
flame, attach a reflux condenser, and maintain gentle ebullition for
exactly 10 minutes. Remove from the flame and cool in running
water for 4 or 5 minutes.
Titration of reduced copper.—Add exactly 25 ml of the iodate—iodide
Solution and 20 ml of saturated potassium oxalate solution. Acidify
carefully, while swirling, with 20 ml of 5 N sulfuric acid. Carefully
shake with a rotating motion until the precipitate of cuprous oxide
(which is partly converted into white cuprous iodide) has dissolved,
and titrate with 0.05 N thiosulfate. No further addition of starch
should be required. The end point is distinguished by a sharp change
to a fine light blue (the color of the cupric salt).
Calculation of levulose.—The difference between the titrations of the
sample serum and the control serum, as milliliters of 0.05 N thiosulfate
solution, multiplied by 0.064, gives the percentage of levulose in the
sample, uncorrected for the volume of the clarification precipitate.
This factor is strictly correct only for a 20-percent serum, that is, if
exactly 40 g of condensed milk is diluted to 200 ml in the preparation
of the serum.
(c) SICHERT AND BLEYER MODIFICATION OF BARFOED COPPER ACETATE
METHOD FOR MONOSES
Barfoed [65] found that copper acetate in the presence of acetic
acid was reduced by monosaccharides but not reduced to any great
Polarimetry, Saccharimetry, and the Sugars 207
extent by the disaccharides, maltose and lactose. Steinhoff [66] modi-
fied the Barfoed solution by substituting sodium acetate for the acetic
acid. This strongly buffered solution had a pH of 6.4, which remained
unchanged during the reduction, whereas the Barfoed solution con-
tinually lost acetic acid.
Sichert and Bleyer [67], using Steinhoff solution, formulated a de-
tailed method of analysis which, however, required the use of a
specially designed filter. This unnecessary complication has been
avoided in the procedure of the Corn Products Refining Co., which,
through the courtesy of that company, has been brought to our
attention.
Reagents.-(1) Copper solution, 69.28 g of CuSO4.5H2O per liter.
(2) Sodium acetate, 500 g of NaC2H8O2.3H2O per liter.
(3) Ferric sulfate, 120 g of Fe3(SO.). (NH4)2SO4.24H2O (or 50 g of
Fe2(SO4)3) and 100 ml of concentrated H2SO, per liter.
(4) Potassium permanganate, 0.1 N, standardized against pure
Sodium oxalate.
Determination.—Into a wide-necked 250-ml Erlenmeyer flask intro-
duce 10 ml of copper solution, 20 ml of sodium acetate solution, and
20 ml of a sugar Solution containing less than 100 mg of dextrose.
The flask, equipped with a Bunsen valve, is placed into a calmly boil-
ing water bath for exactly 20 minutes. The flask should be out of line
with steam bubbles and should be immersed up to the neck.
Filter the precipitated cuprous oxide through washed asbestos in a
Gooch crucible, and wash the flask three times with hot distilled
water. It is not necessary to transfer the precipitate quantitatively.
Transfer the crucible to a 150-ml beaker, which bears a mark at 60
ml. Wash the precipitation flask with exactly 20 ml of ferric sulfate
Solution divided in three portions. Add all washings to the beaker.
Care must be taken to dissolve all of the red precipitate. Wash the
flask with hot water. Remove and wash the crucible and add water
to the 60-ml mark. Bring the solution to boiling on a hot plate,
allow to stand 3 minutes, and titrate with permanganate to a pink-
gray color, which persists for about 20 seconds. The addition of 1 ml
of sirupy phosphoric acid at a late stage of the titration facilitates
reading the end point. Refer the volume of permanganate to table
102, p. 607.
(d) MONIER-WILLIAMS MODIFIED BARFOED METHOD FOR MONOSE SUGARS IN
CONDENSED MILK [68] -
Copper reagent.—Dissolve 60 g of crystallized sodium acetate in
water, add 105 ml of N acetic acid and make up to 1 liter. Transfer
to a dry bottle, add 52 g (or more) of finely powdered crystallized
copper acetate, and shake to saturation, and filter.
Ferric sulfate solution.—Dissolve 50 g of ferric sulfate in about 400
ml of water to which 109 ml of concentrated sulfuric acid has been
added. Make to 1 liter and filter. Before use, this solution should
be treated with 0.1 N permanganate until the color of the latter ceases
to be discharged.
Clarification.—Transfer to a 100-ml beaker an accurately weighed
quantity, approximately 40 g of the well-mixed sample, add 50 ml of
hot distilled water (80° to 90° C), mix, and transfer to a 200-ml
measuring flask, washing in with successive quantities of water at
60° C until the total volume is 120 to 150 ml. Mix, cool to air tem-
208 Circular of the National Bureau of Standards
perature, and add 5 ml of dilute ammonia solution (1+9, approx.
1.43 N). Again mix, and allow to stand for 15 minutes. Add a
sufficient quantity of dilute acetic acid (approx. 1.43 N) exactly to
neutralize the ammonia added and again mix. Add with gentle
mixing 12.5 ml of zinc-acetate solution (21.9 g of Zn (C2H5O2)3.2H2O+3
ml of glacial acetic acid per 100 ml) and subsequently 12.5 ml of
potassium-ferrocyanide solution (10.6 g per 100 ml). Adjust the
temperature to 20° C and fill to 200 ml. In all operations avoid the
formation of air bubbles. Mix thoroughly, allow to stand for a few
minutes, and filter, rejecting the first 25 ml of filtrate.
Determination.—Introduce 25 ml of milk serum (40 g of condensed
milk in 200 ml, clarified with zinc ferrocyanide) into a thin-walled
boiling tube (8 by 1% inches), add 70 ml of the copper solution, mix,
cover with a watch glass, and immerse to the level of the liquid in the
tube in a large water bath maintained at 80° C for 20 minutes. Re-
move, cool in running water, filter on asbestos with suction, wash the
tube and filter rapidly a few times with freshly boiled water. Dissolve
the cuprous oxide in the tube and filter in 20 ml of the ferric sulfate
solution. Wash the asbestos pad with cold water and add the wash-
ings to the ferric sulfate filtrate. Titrate with 0.1 N permanganate
to faint permanent pink.
Table 27 is applicable to 25 ml of the milk serum containing 5 g of
condensed milk.
TABLE 27.-Determination of monose sugar in condensed milk
[5–g sample]
MOnOSe Milliliters of 0.1 N permanganate
Sugar as MonoSe Solution for—
percentage Of Sugar in
condensed Seru In
milk Levulose Dextrose | Invert Sugar
7ml Tng 7ml Trºl 7ml
- - - 0 a0. 15 a0. 15 a 0.15
0. 1 5 3. 50 2. 7 2.8.
... 2 10 5. 50 4. 75 4.25
... 3 15 7.35 6. 0 6, 15
. 5 25 11. 55 8. 75 9.85
1. 0 50 19.50 15.45 18.0
2. 0 100 34.05 25, 35 29.45
a Blank.
(e) IODOMETRIC DETERMINATION OF ALDOSES
In the presence of iodine in alkaline solution, aldose sugars under
suitable conditions are oxidized quantitatively to their respective
aldonic acids. The postulated reactions for this oxidation are
I2+2NaOHz−2 NaIO-H-NaI-H H2O (49)
RCHO-H-NaIO-i-NaOH−RCOONa+–NaI-I-H2O. (50)
Equations 49, and 50 may be combined to represent the reaction,
which is usually written
RCHO-H-I2+3NaOH−RCOONa+–2NaI-H2H2O. (51)
Polarimetry, Saccharimetry, and the Sugars 209
It was early recognized that the sodium hypoiodite may also react to
form sodium iodate:
3NaIO— NaIOa-H2NaI. (52)
Since sodium iodate cannot oxidize the Sugar in alkaline solution, some
active iodine is lost from the sugar oxidation reaction, but all the
unreduced iodine, that is, all that remains in the form of iodate or
iodite, is recovered when the solution is acidified and titrated with
standard thiosulfate, thus
NaIO + NaI –H H2SO4–-I2 + Na2SO4+ H2O
NaIO3+5NaI-H 3H2SO4–3I2+3Na2SO4+3H2O
I? + 2Na2S2O3—2NaI + Na2S4O6.
The difference between the total iodine added and the excess iodine
as found by the thiosulfate titration represents the amount of iodine
used up in the oxidation of the sugar according to eq 51.
Slator and Acree [69] showed that a check on the iodine value
could be obtained by titrating with standard alkali the free acid left
after completing the iodine titration.
HCl–H NaOH->NaCl-H H2O.
Sugar acid lactone-H H2O=2RCOOH.
RCOOH-L NaOH->RCOONa+ H2O.
As shown by eq 51, for every two equivalents of iodine used, three
equivalents of acid are produced. The final acidimetric titer should
then be three halves as great as that of the iodine consumed.
In its earliest form, the method was first devised by Romijn [70],
who used buffer salts, such as alkaline carbonates, bicarbonates,
phosphates, and borax, to supply the alkalinity in order to avoid the
overoxidation which he found occurred with caustic alkali. Later,
many investigators who had used buffer salts found that extended
periods of time were required to complete the oxidation of the sugar
in these weakly alkaline media and that consistent results were not
always obtainable. In the most widely used methods, caustic alkali
is employed.
The difficulties which must be overcome in standardizing the
analytical procedure can be summarized briefly. If the whole re-
quired volumes of alkali and iodine are admitted to the sample simul-
taneously, much of the iodine is transformed to iodate by eq 52.
This may leave a deficiency of iodine for the oxidation reaction. If
the iodine is present in too great excess, overoxidation can occur.
Kline and Acree [71] showed that while the ratio of alkali to iodine
consumed by the aldehyde group was 3:2, the ratio in the oxidation
of sucrose or levulose proved to be 5:4, indicating that the primary
alcohol group was slowly oxidized to a carboxyl group. Conceivably
the overoxidation of an aldose proceeds similarly. The rate of addi-
tion of the reagents has an important bearing on the results. In the
analysis of a mixture of aldose and ketose, such as dextrose and levu-
lose, it is important that the levulose remain unoxidized. If too
great an excess of alkali is present the levulose can undergo the
Lobry de Bruyn-van Ekenstein rearrangement to dextrose and man-
210 Circular of the National Bureau of Standards
nose, which are rapidly oxidized by iodine. The time of reaction has
undergone endless variation in the specifications, from 24 hours,
according to Romijn, to 2 minutes, according to Kline and Acree.
Observers agree, however, that in the presence of sodium hydroxide
the reaction is rapid, and that short periods of time are sufficient.
Space permits the inclusion of only four of the many procedures that
have been described.
Method of Willstäter and Schudel [72].—To the aldose solution con-
taining from 1 to 100 mg of sugar, add about twice (1.5 to 4 times)
the volume of 0.1 Niodine required for Oxidation. At room tempera-
ture and with effective stirring, add dropwise 1.5 as much 0.1 N
NaOH as iodine (from alcohol-free sodium hydroxide) and allow the
mixture to stand at room temperature for 12 to 15 minutes (for small
amounts of sugar, 20 minutes). Add dilute sulfuric acid to slight
acidity and titrate the excess of iodine with 0.1 N thiosulfate, using
starch indicator. Deduct the excess iodine from the volume origi-
nally added. The amount of reducing sugar is calculated from the
difference where 1 ml of 0.1 N Ig=9.00 mg of hexose or 7.50 mg of
pentose.
Kline and Acree [71] have criticized the procedure of Willstäter and
Schudel on the grounds that the great excess of iodine in general
tends to cause overoxidation. Occasional low results are probably
caused by the formation of iodate, which removes iodine from the
reacting system. Apparently, as Goebel [73] showed, the rate of
addition of alkali requires delicate adjustment. If added over a
period of 2 to 4 minutes, correct results were obtained. If added
more rapidly, the recovery was low.
Method of Kline and Acree [71].—Kline and Acree have devised a
procedure by which any considerable excess of either alkali or iodine
is avoided, thus eliminating the errors due to iodate formation and
overoxidation.
Transfer to an Erlenmeyer flask a weighed sample or aliquot con-
taining approximately 180 mg of aldohexose or 150 mg of aldo pentose
and neutralize exactly (phenolphthalein, 1 drop only). Add 5 ml
of 0.1 Niodine from a burette; then add drop by drop from a burette
7.5 ml of 0.1 N NaOH. Repeat this process until 22 ml of iodine
and 35 ml of alkali solution have been run in, the operation requiring
about 5 to 6 minutes. Allow a 2-minute interval for the completion
of the oxidation. Acidify with 0.1 N (or 0.2 N) HCl and titrate the
liberated iodine with 0.1 N thiosulfate (starch indicator). Add 2 to
3 drops of phenolphthalein and titrate the excess acid with 0.1 N
NaOH. Deduct the thiosulfate titer from the number of milliliters
of iodine added and deduct the hydrochloric acid titer from the num-
ber of milliliters of alkali added. The results will be the number of
milliliters of iodine and alkali, respectively, consumed by the oxida-
tion reaction. Then 1 ml of iodine equals 9.0 mg of hexose or 7.5
mg of pentose, and 1 ml of alkali equals 6.0 mg of hexose or 5.0 mg
of pentose.
NotEs.—The ratio of volumes of alkali to iodine should be 3:2
if the reaction is confined to the aldehyde group alone. A departure
from this ratio shows that other groups or other substances, such as
lignins, are being oxidized. If assurance is had that only sugars are
oxidized, and if it is desired to diminish the labor of analysis, either one
of the two titrations may be omitted.
Polarimetry, Saccharimetry, and the Sugars 211
The back titration should require about 2 ml of thiosulfate. If
the titer exceeds this, it is probable that over oxidation has occurred;
if less, an insufficiency of iodine has been added. It is therefore ad-
visable in such instances to repeat the analysis and to use more or less
of the reagents, as indicated by the trial analysis.
A small amount of the lactone of the sugar acid is found after
acidification, which will result in a fading end point with phenolphtha-
lein. However, when the titration is carried out in a stoppered flask
and the alkali is added slowly, a pink color which persists for 1 minute
or longer may be taken as the end point.
Lothrop and Holmes method for the determination of deactrose and
levulose in honey by the iodime-oridation method.—Lothrop and Holmes
[74] have recommended a procedure which is essentially the same as
that of Willstäter and Schudel but specifically adapted to the analysis
of honey. They recognized that levulose was slightly oxidized under
the conditions of analysis, but the amount of oxidation was found to be
an approximately constant percentage (1.2) of the levulose present
and permitted the application of an empirical correction. The oxida-
tion of levulose was found to vary rapidly with temperature, and hence
the correction applied is valid only for 20°C. Total reducing sugar
was determined by the Munson and Walker method and calculated as
dextrose. The results agreed with the analysis by the Lane and
Eynon volumetric method. In the following detailed procedure, the
italicized words have been added to the original text.
To 20 ml of a solution containing 0.2 g of honey add 40 ml of 0.05
N iodine solution, using a 250 ml Erlenmeyer flask. Run in 25 ml of
0.1 N sodium hydroxide slowly and with continuous agitation, stopper,
and allow to stand 10 minutes at a temperature of 20° C. Acidify
with 5 ml of 2 N sulfuric acid and titrate at once with 0.05 N. sodium
thiosulfate, using starch indicator. The weight of dextrose in grams
(not corrected for reduction of iodine by levulose) is found by multi-
plying the milliliters of 0.05 Niodine reduced by 0.004502. Calculate
as follows:
LA = approximate percentage of levulose,
R = percentage of total reducing sugars calculated as dextrose
(Munson and Walker),
Dr=percentage of apparent dextrose (iodometric),
L = true percentage of levulose,
D = true percentage of dextrose.
Then introducing numerical values,
L = 1.081 (R—D),
in which the factor 1,081 is the reciprocal of 0.925, the reducing
ratio of levulose to dextrose at the nearly constant concentration of
reducing sugars specified by the method.
(f) HINTON AND MACARA CHLORAMINE-T METHOD FOR THE DETERMINATION
OF ALDOSES [75]
A solution of Chloramine-T behaves like sodium hypochlorite in
producing hypoiodite and a certain amount of free iodine when excess
potassium iodide is added. It is believed that the reaction takes place
212 Circular of the National Bureau of Standards
through an intermediate hydrolysis of the Chloramine-T to hypo-
chlorite. The reactions which appear to occur are indicated by the
following equations:
C.H.S.O., Na. NCI-I-H2O->C.H.SO.H. NH-H NaClO
NaClO-|-KI—-NaCl- KIO
KIO-H-KI+ H2O->2KOH-HT2 (to a small extent before acidi-
fication).
The hypoiodite can be used for the oxidation of aldoses.
KIO-I-C. HiſO3CHO=C.H.I.O.COOK-l-HI.
Upon acidification, the iodine equivalent of the unaltered Chloramine-
T, and any unused hypoiodite can be determined by means of
thiosulfate.
C.H.S.O., Na. NCl–H2HCl·H-2KI— C, H2SO.H. NH-i-NaCl-H2KCl–H Ig.
This oxidation proceeds more slowly than when alkaline iodine solution
is used and hence it is more easily controlled.
Reagents.-0.05 N. Chloramine-T solution containing 7.04 g/liter
freshly prepared and protected from the light. Standard sodium
thiosulfate solution, preferably slightly stronger than 0.05 N.
Sodium hydroxide solution, 0.5 N.
Sodium hydroxide solution, 0.1 N.
Potassium iodide solution, 10 percent.
Soluble starch solution.
Procedure.—Pipette 20 to 25 ml of sugar solution containing about
0.1 g of sugar, into a 250-ml Erlenmeyer flask. Add 20 ml of 10-per-
cent KI solution and 0.8 ml of 0.5 N sodium hydroxide followed by
50 ml of 0.05 N. Chloramine-T solution. Close the flask with a rubber
stopper and allow it to stand 1% hours in a water bath at 17.5° C.
Acidify with 10 ml of 2 N HCl and titrate at once with standard
sodium thiosulfate solution.
1.410 g of iodine= 1 g of dextrose.
0.706 g of iodine=1 g of lactose.
.710 g of iodine=1 g of invert sugar.
Sucrose has little effect on the oxidation of aldoses except in mixtures
where there is only a small amount of the aldose present. Levulose,
although unaffected in neutral solution under the conditions given
above, has an apparent iodine equivalent of 0.007. This method has
been studied by the authors in its application to condensed milk.
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214 Circular of the National Bureau of Standards
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X. ANALYSIS OF SUGAR MIXTURES
1. INTRODUCTION
For the analysis of a sugar mixture it is generally necessary to have
as many different analytical processes as there are sugars. These
methods should be selected in such a way that the most varied prop-
erties of the sugars are represented. A consideration of some of these
properties follows.
Total sugar.—In a relatively few instances, total sugar can be
determined in a mixture by densinetric, refractometric, or desicca-
tion methods. Obviously, such methods can be applied only to
Solutions uncontaminated with nonsugars. The densities and refrac-
tive indices of the pure constituents must be known, and in most
instances it must be assumed that the properties of the mixture are in
linear relation with those of the constituents. In crude materials
these methods are more frequently used for the determination of total
dry substance than for total sugars and thus are contributory to the
determination of purity.
Polarizing power.—This property can be expressed in terms of
specific rotation for a monochromatic wave length or as the rotation
per gram in 100 ml, in terms of the saccharimetric scale, or as the
ratio of the specific rotation of the sugar in question to that of sucrose.
For many sugars the specific rotation varies appreciably with con-
centration, and the tendency at present is to select the concentration
of total substance rather than the partial concentration of each
sugar in assigning the value of the specific rotation for the calculation.
The specific rotations of the sugars are tabulated on page 563.
Reducing power.—For the purposes of calculation, it is convenient
to state the reducing powers of the various sugars in terms of that of
dextrose. The “reducing ratio” may be defined as the ratio of weights
of dextrose to the sugar in question which produce the same weight of
reduced copper. Thus by the Allihn method, 240 mg of levulose is
required to reduce the same weight of copper as 219.5 mg of dextrose.
The reducing ratio of levulose is then 0.915. In the study of starch
and its Scission products, maltose is frequently used as the unit of
Polarimetry, Saccharimetry, and the Sugars 215
reducing power. In some cases levulose is taken as the sugar of unit
reducing power.
Usually the reducing ratios of dextrose to the various sugars vary
Somewhat with the concentration of sugar. Thus Jackson [1], using
the Munson and Walker method, found that the reducing power of
levulose varied from 0.912 for 89 mg of copper to 0.937 for 375 mg of
copper. With the Allihn method, the ratios appear to be more nearly
independent of concentration. Browne [2] found the following reduc-
ing ratios for the Allihn method: Levulose 0.915; arabinose, 1.032;
xylose, 0.983; galactose, 0.898; invert sugar, 0.958. The ratios for
the more common sugars can, for the Munson and Walker method, be
calculated from table 78, p. 564. The most comprehensive table of
reducing ratios, including both common and unusual sugars, is that
of Isbell, Pigman, and Frush (table 23, p. 190), who employed a
modification of the Scales method.
2. SELECTIVE METHODS
(a) RECAPITULATION OF PREVIOUSLY DESCRIBED METHODS
Many of the methods of analysis described in detail in previous
chapters are selective for the respective sugars and are directly appli-
cable to their determination when they occur in admixture with other
sugars. Thus the Clerget method is selective for sucrose and raffi-
nose and is particularly free from analytical error when invertase is
used as the inverting agent.
Levulose is selectively determined by the modified Nyns procedure,
as described on page 203, but in this case corrections must be applied
for the slight reduction by other sugars.
Aldoses can be distinguished from ketoses by oxidation to aldonic
acids in mildly alkaline solution (p. 208).
Monoses can with fair approximation be determined in the presence
of reducing disaccharides by the modified Barfoed procedure (p. 206).
Pentoses and pentosans upon distillation in the presence of hydro-
chloric acid yield furfural, which can be estimated as described on
page 241. -
These selective methods, as well as the general methods described
above, can be combined in a great variety of ways for the analysis
of sugar mixtures. It is usually true, however, that the application
of the selective methods to actual mixtures must be made with
caution, since frequently unexpected complications are encountered.
It is for this reason that in the following pages will be described only
those applications which have been thoroughly studied.
(b) INVERT SUGAR BY POLARIZATION AT TWO TEMPERATURES
By polarization of a solution at two widely separated tempera-
tures, invert sugar or levulose can be determined selectively in the
presence of other sugars, since the levulose constituent of invert sugar
possesses a high temperature coefficient, whereas the rotatory power
of dextrose is independent of temperature. Browne, however, [3, p.
298], points out that 1.5 g of arabinose, 3.0 g of galactose, 7.0 g of
maltose, 9.0 g of lactose, or 50 g of sucrose, in 100 ml produces approxi-
mately the same change of polarization with change of temperature
as 1 g of levulose or 2 g of invert sugar. In some instances, the
216 Circular of the National Bureau of Standards
partial change of rotation of these sugars with temperature can be
applied as a correction.
Gubbe's [4] comprehensive formulas for the specific rotation of
invert sugar can be solved for the change of its rotation with change
of temperature or for the temperature of complete inactivation.
This inactivation is due to the fact that since the rotatory power of
levulose diminishes with increasing temperature, while that of dex-
trose remains constant, there is some temperature at which the two
rotations are equal and opposite. Gubbe's formulas
[o]}= – 19.657–0.0361C (53)
[o]} =[o]}}+0.3246 (t–20)—0.00021 (t–20)” (54)
indicate that the specific rotation at 20° C is variable with concen-
tration but that the temperature coefficient is independent of con-
centration. The temperature of inactivation therefore is not a
constant but a function of concentration.
|Browne [3] has calculated that the temperature of inactivation
varies with concentration of invert sugar from 83.2° C for 2 g to
90.2°C for 60 g in 100 ml. For general purposes, 87° C is usually
taken as the temperature of optical inactivity of invert sugar.
On the other hand, the temperature coefficient of the rotation of
invert sugar is 0.0180° S for each gram in 100 ml, regardless of con-
centration. Hence invert sugar without any assumption of a tem-
perature of inactivation can be determined by
P’ — P te
00ISO(7–1)=grams in 100 ml, (55)
in which P’ is the saccharimetric reading at t' and P the reading
at t in a 200-mm column. Obviously, any pair of temperatures
sufficiently separated will serve for the determination.
The suggestion seems valid that the method of determination by
temperature coefficient is more reliable than that of polarization at
the temperature of inactivation. Not only is there considerable
experimental difficulty in accurately maintaining a temperature of
87° C, but there remains the uncertainty that inactivity has been
attained. The method of temperature coefficient is free from these
uncertainties, since any pair of temperatures will serve, provided
they are accurately observed.
After the temperature coefficient has been determined, the invert
sugar is calculated by formula 55. If it is desired to determine the
other constituent of the mixture, the rotation of the invert sugar
at 20° C (P20) can be substituted into the low-temperature polariza-
tion by reference to table 76, p. 563, which is computed from the
Gubbe specific rotation formula 53, in which C refers to the con-
centration of total solids in 100 ml. The third column gives the
rotation which each gram of invert sugar contributes to the total
rotation at various concentrations of sugar. Note that these values
are expressed in Saccharimeter degrees. Peo so found can be trans-
formed to P, if necessary, by formula 55. The rotation of invert
sugar is deducted algebraically from the observed polarization, leaving
a remainder which represents the rotation of the second constituent.
If there is an excess of dextrose, it can be calculated quantitatively
Polarimetry, Saccharimetry, and the Sugars 217
by dividing its rotation by that of 1 g of dextrose at the concentra-
tion of total sugals in the mixture. The rotation of dextrose can be
Selected from table 74, p. 562.
Frequently the second constituent of the mixture is commercial
glucose. This product as manufactured in this country is a liquid of
density varying from 41° to 45° Baumé, and has a specific rotation
varying from 100° to 125°. Obviously no exact determination is
possible by means of polariscopic measurement, but if a specific
rotation of say 108° is arbitrarily assumed, a measure of the constituent
is obtained by dividing the observed rotation (corrected by deducting
the rotation of the invert sugar) by 0.1600, the polarization of 1 g of
the liquid product. The analyst should always state the specific
rotation which is assumed for the purpose of calculation.
Any other probable specific rotation can be assumed for the purposes
of this calculation, and the appropriate divisor can be found in table
28, which is taken from Browne's Handbook of Sugar Analysis [3].
TABLE 28.-Rotatory power of commercial glucose
Liquid in 100
ml giving a
rotation of
19 S
Liquid in 100
ml giving a
rotation of
10 S
[o] D (for Polarization
liquid prod- of 26 g in 100
uct) ml
[a] D (for | Polarization
liquid prod- of 26 g in 100
uct) ml
Degrees o S g Degrees o S g
+125- - - - - - 188.0 0. 1383 108 162. 5 0.1600
120-------- 180. 5 . 1440 105 157. 9 . 1647
115-------- 172.9 . 1503 100 150. 4 . 1729
110- - - - - - - - 165.4 . 1572
(c) LEVULOSE BY POLARIZATION AT TVO TEMPERATURES
By the procedure outlined in the previous section, levulose can be
determined by polarization at two temperatures. The change of
rotation of 1 g of levulose per degree change of temperature should be
exactly twice as great as that of invert sugar, or 0.036. Wiley [5]
gives the value 0.0357. The average computed value of five previous
investigations [3] is 0.0362, the difference between the extreme values
being about 20 percent. On the other hand, Jackson and Mathews
[6] in an extended investigation found experimentally between 20°
and about 70° C a coefficient of 0.03441. The value was found to be
independent of concentration between 3 and 18 g of levulose in 100
ml. There is thus an outstanding, discrepancy of 4.5 percent between
the older values of the temperature coefficient and the recent experi-
mental determination of Jackson and Mathews. The lower value of
the coefficient has been closely verified by Lothrop [7], who found in
a limited number of experiments between 20° and 70° C a mean value
of 0.0341. By application of the Jackson and Mathews coefficient,
0.03441, to the analysis of levulose in honey, Lothrop found a close
agreement with the levulose percentage as determined by chemical
methods.
This important coefficient requires further investigation. Not
only is it divergent from Wiley's value, but it is inconsistent with the
invert-sugar coefficient, 0.018, which should be exactly half that of
levulose. It is apparent that the coefficient remains constant with
varying concentration of sugar, but to what extent it is constant
between different temperature intervals is at present undetermined.
218 Circular of the National Bureau of Standards
Until further investigations are made, it is to be recommended that
the temperature interval 20° to 70° C be employed with the coefficient
0.03441, that is, 1 g of levulose in 100 ml of solution in a 200-mm col-
umn diminishes 0.03441° S for each degree rise of temperature. The
mean expansion coefficient between these temperature limits is,
according to Jackson and Mathews, 0.00044. Thus if the higher
temperature is exactly 70°, the observed polarization must be multi-
plied by 1.022 before subtracting from the polarization at 20° C.
The decrease in the corrected polarization divided by 0.03441 yields
the number of grams of levulose in 100 ml of solution.
(d) GALACTOSE BY MUCIC ACID PRECIPITATION
Galactose is oxidized by nitric acid to yield about 75 percent of
mucic acid. Under closely specified conditions of analysis, the quantity
of recovered mucic acid is reproducible and can be related empirically
to the quantity of galactose in the sample. The method is applicable
to free galactose or to the combined galactose in compound sugars
or in galactans. Certain glycosides containing galactose, for example,
Saponins, yield insoluble products upon hydrolysis. Such glycosides
must first be hydrolyzed with sulfuric acid (2 to 5 percent) and the
insoluble material separated by filtration [8].
van der Haar [8] has given detailed specifications for the analytical
procedure. Transfer the weighed sample containing galactose to a
beaker (12 cm in height and about 60 mm in diameter) and add
sufficient sucrose to increase the weight of total sugar to 1.000 g.
Add 60 ml of nitric acid (sp gr 1.15 at 15° C) and place the beaker
in an inclined position in a boiling-water bath and with repeated
agitation allow it to remain until the weight of the contents has
diminished to somewhat less than 20 g (that is, 19.8 to 20). Cool,
and add water to make the weight exactly 20 g. Add 500 mg of pure,
dry mucic acid and allow to stand for 48 hours at approximately
15° C, during which time stir occasionally. During the last few
hours, adjust the temperature to exactly 15° C. Filter the precipi-
tated mucic acid with suction on a weighed Gooch crucible prepared
with asbestos which has previously been treated with nitric acid.
Wash the precipitate four times with 5 ml of a solution of mucic
acid saturated at 15° C and finally with 5 ml of water. Dry the
precipitate at 100° C to constant weight. Deduct 500 mg from the
weight of the precipitate and refer the result to column 3 of table
103, p. 608.
Acree [9] states that the oxidation of galactose by nitric acid is ac-
celerated by the oxides of nitrogen, hence if the nitric acid is too pure
it is preferable to add a small quantity of nitrous acid or an alkali
nitrite.
(e) DETERMINATION OF. MANNOSE AS PHENYLHYDRAZONE
While all reducing sugars are capable of forming hydrazones, the
hydrazone of mannose is particularly insoluble and thus is suitable
for its quantitative estimation. Bourquelot and Hérissey [10]
prescribe the conditions of analysis. About 1 g of mannose dissolved
in 16.6 ml of water is treated with a solution of 1.2 ml of phenylhydra-
zin and 1.2 ml of glacial acetic acid made up to 6 ml with water, and
allowed to stand for 8 hours at a temperature not above 10° C. The
hydrazone is collected on a Gooch crucible and washed with 15 ml
Polarimetry, Saccharimetry, and the Sugars 219
of ice water, 10 ml of absolute alcohol, and 10 ml of ether. The
precipitate is dried in a vacuum over sulfuric acid. One gram of
mannose yields theoretically 1.5 g of phenylhydrazone.
The hydrazone is soluble to the extent of 40 mg in 100 ml of solution
and a small correction for this solubility increases the precision of
analysis.
Pellet [11] has found the method suitable for the estimation of
small amounts of mannose in cane molasses.
(f) DETERMINATION OF ARABINOSE AS DIPHENYLHYDRAZONE
Neuberg and Wohlgemuth [12] have made use of the high in-
solubility of arabinose diphenylhydrazone for estimating arabinose
in the presence of other monosaccharides. Mannose or fucose in
excessive quantities are apparently the only sugars which interfere
with the selectivity of the analysis. The authors illustrate the
method by the following example.
A solution (100 ml) containing dextrose, fructose, xylose, glucuronic
acid, and 1.0066 g of arabinose was evaporated to 30 ml. The re-
sulting solution was heated on a water bath for 9% hour with 6 g
of diphenylhydrazine in 50 ml of 96-percent alcohol with additions
of very dilute alcohol or preferably with a reflux condenser. The
solution was cooled and allowed to stand for 24 hours. The pre-
cipitated hydrazone was collected on a Gooch crucible, washed with
50 ml of 50-percent alcohol, dried, and weighed. Yield, 2.1143 g of
hydrazone, equivalent to 1.0035 g of arabinose. Factor, 0.4747.
(g) DETERMINATION OF URONIC ACIDS
The uronic acids, glucuronic and galacturonic, are widely dis-
tributed in both plants and animals. They play an important role
in the carbohydrate metabolism of the cell wall. Dickson, Otterson,
and Link [13] have found that free glucuronic acid is present within
the cell of corn seedlings and that a polymerized glucuronic acid
sometimes associated with the cellulose, comprises part of the
pectinaceous substance of the cell and cell wall. Nanji, Patin, and
Ling [14] found that purified pectin preparations contained from 70
to 73 percent of uronic acid anhydride. Browne and Phillips [15]
showed that uronic acids comprised about 3 percent of sugar-cane
bagasse and that sugar-cane juice contained from 0.1 to 0.6 percent
(based on ash-free solids) of uronic acids, the variations depending
upon the methods of maceration. In cane molasses the uronic acids
were found concentrated to an average of about 2 percent. These
authors believed that the uronic acids are derived from pectins which
are extracted with the juice.
When a uronic acid is heated with hydrochloric acid, decarboxyla-
tion occurs with the formation of furfural and carbon dioxide accord-
ing to the equation
C6H10O. = C.H.O. + CO2 + 3H2O.
The yield of furfural is less than the theoretical, while that of carbon
dioxide is quantitative. In the absence of other reactions yielding
carbon dioxide, a measure of the gas evolved serves for the quantitative
determination of uronic acid.
220 Circular of the National Bureau of Standards
Whistler, Martin, and Harris [16] in a study of the determination
of uronic acids in cellulosic materials, found that under the drastic
conditions employed in the analysis, carbohydrates free from uronic
acids were slowly but regularly decomposed with the formation of
carbon dioxide, necessitating the application of a correction.
The method of determination was originally devised by Lefèvre
and Tollens [17]. Dickson, Otterson, and Link [13] further elaborated
the method, measuring the carbon dioxide by absorption in barium
hydroxide and titration of unreacted alkali.
The details of the method described here are those of Whistler,
Martin, and Harris [16], who adapted the procedure specifically to
the determination of uronic-acid groups in cellulosic materials. Their
procedure can, however, be used without modification for any other
material by selecting a weight of sample which will yield 30 to 40 mg
of carbon dioxide.
† ſ
A B C C D
FIGURE 39 (a).-Apparatus for determination of the rate of evolution of carbon
dioxide from uronic acids or materials containing wronic acids during treatment
with hydrochloric acid.
The apparatus is not drawn to scale. See original article for dimensions.
The apparatus is shown in figure 39 (a). Nitrogen, which is used
as the carrier gas for the evolved carbon dioxide, enters the apparatus
through an empty safety bottle, A. It next passes through an alkaline
solution of pyrogallol, B. The inlet tube in this bottle is drawn out
to a small orifice, which produces very fine bubbles. From B the gas
passes through two absorption towers, C, filled with soda lime, into
a second safety bottle, D, which is provided with a mercury ma-
nometer, E, and then enters the reaction flask, F, by way of a side arm
whose outlet is 10 to 15 mm above the surface of the liquid in the
flask. The size of the flask depends upon the type of material and
the size of the sample to be analyzed. In most experiments a 500-ml
reaction flask is suitable. From the reaction flask the gas passes
through a 40-cm reflux condenser, G, and into a bubbling tower, H,
containing approximately 60 ml of concentrated sulfuric acid. The
sulfuric acid serves to remove interfering decomposition products
which are carried over from the reaction flask. The gas next passes
through the U-tube, I, which is filled with anhydrous copper sulfate
to remove chlorine or hydrogen sulfide, then through the tube, J,

Polarimetry, Saccharimetry, and the Sugars 221
which contains phosphorus pentoxide, and finally through the carbon
dioxide—absorption tube, K, containing Ascarite, backed by phos-
phorus pentoxide. The absorption tubes, K, are connected into the
train by means of mercury-cup seals [18]. This type of connection
makes possible a rapid exchange of the absorption tubes. Tube K
is protected by a soda-lime tube, L, which is followed by a calibrated
flowmeter, M, for estimating the rate of flow of nitrogen through the
apparatus.
The reaction flask is immersed in a vessel containing about 16 liters
of hydrogenated cottonseed oil. A bath temperature of 130° C was
found to be optimum for maintaining a steady but gentle boiling of
the reaction mixture. The bath is brought to the operating tem-
perature by means of two electric immersion heaters, one of 500 and
one of 1,000 watts. When the desired temperature is reached, the
500-watt heater alone is sufficient to maintain thermal constancy
within +0.2° C. The time required to raise the temperature of the
bath to 130°C is approximately 50 minutes.
The flask is placed in position in the oil bath so that the oil level is
3 to 4 mm lower than the liquid level inside the flask. This precau-
tion is taken to prevent the baking of small bits of sample which may
be splashed against the sides of the flask. Nitrogen, at the rate of
about 10 liters per hour, is passed through the apparatus until the
Ascarite tube, K, shows no further gain in weight. This operation
requires about 30 minutes, during which time the temperature of the
oil bath is slowly raised to 50° C. When the apparatus is free of
carbon dioxide, both heating units are turned on and the temperature
is brought to 130° C. This procedure is always carefully followed in
Order to assure the same preliminary heating for all samples. The
point of zero time is taken as the time at which the bath reaches 130°
C. At that time the Ascarite tube, K, is removed for weighing and
a second weighed Ascarite tube inserted in its place. At the end of
1 hour the second tube is removed for weighing and replaced by the
first. This process is repeated at intervals of 1 hour for the duration
of the analysis. When analyses are made of pure uronic acids or
materials rich in uronic acids, a small amount of carbon dioxide is
evolved by the time the temperature of the bath reaches 130°C. In
these cases, this amount is measured and added to that evolved
during the first hour.
Since the rate of evolution of carbon dioxide is appreciably affected
by variations in acid strength, it is essential that the same concentra-
tion (within 0.02 percent) of hydrochloric acid be used in all analyses.
The acid should be accurately 12 percent, or 3.290 N.
To determine the correction for the carbon dioxide evolved by
decomposition of carbohydrates other than uronic acids, weigh the
Ascarite containers hourly until the rate of increase in weight is con-
stant. The constant rate of evolution indicates that the carbon
dioxide is being derived solely from the uronic acid-free carbohydrates.
Calculate from the determined increase per hour the total weight of
carbon dioxide which was evolved during the period (3 to 5 hours)
before the rate became constant, and deduct the computed weight
from the total evolved during this period. The weight of carbon
dioxide times 4.00 equals the weight of uronic acid anhydride.
323414°–42—16
222 Circular of the National Bureau of Standards
3. DETERMINATION OF TWO SUGARS IN A MIXTURE
(a) TWO SUGARS BY COMBINATION OF TWO POLARIMETRIC EQUATIONS
In many instances it is possible to polarize a sugar mixture under
conditions sufficiently different to emphasize some striking difference
in the properties of the two sugars. The variation in specific rotation
of the two individuals under the varied conditions must be known in
order to substitute in the two corresponding equations. If a and y are
the respective percentages of each sugar in the mixture, a and a' the
known specific rotations of one of the sugars under the two varied
conditions, and b and bº those of the second sugar,
aw-H by = 100|o]p (56a)
a'a-H bºy=100|o]p', (56b)
in which ſolo and [o]o' are determined experimentally. The specific
rotations can obviously be replaced by the saccharimetric constants.
While it is possible theoretically to determine both constituents of
a mixture by the procedure outlined, the method is most frequently
used to determine one constituent selectively in the presence of an
optically active impurity. Thus the Clerget method, which has been
described in detail, is employed for the determination of sucrose in the
presence of invert sugar. Theoretically, it should be possible to cal-
culate the invert sugar also, but it is at present difficult to assign with
confidence a definite value to the specific rotation of invert sugar,
since our knowledge of the partial rotatory powers of the constituents
of Sugar mixtures is incomplete.
The principle of the method is used in the determination of mixtures
of sucrose and raffinose by the Creydt raffinose formula, which would
yield exact results for both constituents but for the complication that
usually a third group of optically active substances, namely aminoacids,
contaminates the product which is subjected to analysis.
Other examples of the use of two polarimetric equations have been
cited in the description of the determination of levulose and invert
sugar by polarization at two temperatures. In some instances the
second constituent of the mixture can be determined by calculation
from the residual rotation obtained by deduction of the rotation of the
determined constituent from the observed rotation.
/
(b) TWO SUGARS BY COMBINED POLARISCOPIC AND REDUCTION EQUATIONS
(1) BROWNE FORMULAs.- A thorough study of the determination
of two sugars in a mixture by a combination of polariscopic and reduc-
ing-power methods has been made by Browne [2] and [3, page 475].
Reducing sugars are determined by the Allihn method and polariza-
tions, observed in a 200-mm column, are stated in terms of Wentzke
sugar degrees. Browne showed that by the Allihn method the reduc-
ing power of a sugar mixture is a strictly additive property of the
constituents. The assumption is made tacitly that the polarizing
power is also additive.
If the reducing ratio of sugar A to dextrose is a and of sugar B is b,
then in a mixture of a percent of A and y percent of B, the combined
influence is
aw-H by =R,
in which R is the percentage of total reducing sugars determined as
dextrose.
Polarimetry, Saccharimetry, and the Sugars 223
If the relative polarizing power of sugar A is o. and that of B is
8, then, in the mixture, or—H 3y–P, in which P is the polarizing power
of the mixture of sugars expressed in Wentzke degrees. Hence
aff–ob
_a P- oft_R-aa.
VTag-Taº T b
Relative polarizing power (a and 6) is defined as the ratio of specific
rotation of the sugar in question to that of sucrose. The values of
o, and 8 for 20°C and a concentration of 10 percent are given in table
29. For levulose and galactose these values vary considerably with
concentration and temperature and must be calculated by the formulas
Levulose o- — 1.3393–0.00166p––0.0085 (t–20),
Galactose 8–1.210–H0.0012(p−10)—0.00315(t–20),
in which p is the percentage of the sugar in the solution polarized.
TABLE 29.-Constants applicable to the Browne method of analysis of sugar mixtures
Denominator
Mixture (l b CY 8 ...?o :*
percent
Levulose (A), glucose (B) - - - - - - - - - - - - - - - - - - - - - 0.915 1.00 — 1. 356 0. 793 +2.082
Glucose (A), galactose (B) --------------------- 1. 00 0.898 0. 793 1. 21 +0.498
Levulose (A), galactose (B) - - - - - - - - - - - - - - - - - - - 0.915 . 898 — 1. 356 1. 21 . +2. 325
Levulose (A), arabinose (B)------------------- . 915 1.032 — 1. 356 1. 571 —H2. 837
Xylose (A), arabinose (B) --------------------- . 983 1. 032 0.283 I, 57.1 — 1. 252
The constants required for calculation are given in table 29. The
list is capable of extension as the constants for other sugars are deter-
mined. The values tabulated under a and o refer to the sugar A and
those under b and 8 to the sugar B.
Eacample.—A solution containing 4.52 percent of levulose and 4.84 percent of
dextrose rotated –2.15° W in a 200-mm tube at 22° C and showed a reducing
#. equivalent to 9.06 g of dextrose. By the above formula, o = — 1.3378.
hen
0.793)(9.06— (–2.15)
0.915X 0.793– (–1.3378)
(percentage of dextrose) = 9.06— (0.915X4.524) = 4.92.
(2) MATHEws ForMUL.A.—The most commonly occurring mixture
of two sugars which can be analyzed by a combination of reducing and
polarizing equations is that of dextrose and levulose. Mathews [6, p.
433] has derived a formula which permits a ready calculation of the
ratio of levulose to total reducing sugar when the sample has been
polarized in a saccharimeter and its reducing power determined by the
Lane and Eynon method of titration. The method of calculation is
valid under the assumptions that no optically active or reducing sub-
stance other than dextrose and levulose is present in the sample, and
that the rotation of the mixture is the algebraic sum of the rotations
of the constituents whose specific rotations are referred to the con-
ºtion of total sugar rather than to the partial concentration of
€8,0I).
= 4.524.
2 (percentage of levulose) =
224 Circular of the National Bureau of Standards
While the method of determination strictly applies only to pure
mixtures of dextrose and levulose, it may frequently be applied to
crude mixtures, such as fruit juices, to yield a proximate analysis. At
this Bureau the method has been applied to numerous samples of
hydrolyzed juices of the jerusalem artichoke for rapid proximate
analysis. The sugar mixture in such products consists of about 70
to 80 percent of levulose, about 20 to 25 percent of dextrose, and a
small quantity of dextrorotary difructose anhydrides, which introduces
an error of about 2 percent into the analysis. Application of an
empirical correction diminished the error considerably.
The procedure is simple. If the levulose content is high, prepare a
sample containing 15 to 20 percent of sugars, or somewhat more if
dextrose is the predominating sugar. Polarize in a 200-mm tube, pref-
erably at 20° C. Dilute a measured aliquot to such volume that the
resulting solution contains about 0.5g of sugar per 100 ml and titrate
against 25 ml of mixed standardized Soxhlet solution by the method
of Lane and Eynon. If necessary, correct the burette reading to con-
form to an exactly standardized Soxhlet reagent. The method of cal-
culation is greatly facilitated by use of table 95, p. 601.
Eacample.—Assume that a solution of levulose and dextrose polarized – 43.8°S
at 20°C, and that 5 ml of this solution diluted to 100 ml gave a Lane and Eynon
titration (25 ml of Soxhlet solution) of 26.18. Then D = 100/5 = 20 and
PT - 43.8×26.18 57.3
D T 20 - " ' ".
By table 95, p. 601, the approximate ratio is 89.8 percent, and the correction
factor, f, is — 0.80. The correction is
ſ2.P. -0.80×20 0.6
T T 26.18 “”
and the true ratio is 89.8–0.6 = 89.2. The concentration of total sugar is calcu-
lated in the usual way from the titer
100F_100×127.0
T T 26.18
of the solution titrated. The concentration of total sugar in the polarized solu-
tion is
= 485.1 mg per 100 ml
0.4851 X20=9.702 g per 100 ml.
Levulose is
9.702 × 89.2 percent=8.654 g per 100 ml,
and dextrose is
9.702 X 10.8 percent= 1.048 g per 100 ml.
(c) TWO SUGARS BY COMBINATION OF TWO REDUCTION EQUATIONS
(1) GENERAL.-For analysis of two sugars in a mixture, advantage
is frequently taken of differences in reducing action which the indi-
vidual sugars show under different conditions of analysis. In many
instances the difference in behavior between the two sugars is so
marked that one sugar can be determined selectively. In most
cases the accompanying sugar produces minor effects, and corrections
are required for accurate analysis. Thus Jackson and Mathews in
their modification of the Nyns method found that 12.4 mg of dextrose
reduced as much copper as 1 mg of levulose, but that this constant
correction could be applied with certainty.
The variety of combinations by which this analysis can be con-
ducted is considerable, but quite invariably one process is the de-
Polarimetry, Saccharimetry, and the Sugars 225
termination of total reducing Sugar. The remaining methods of
analysis can be chosen from the group of selective methods, but
should take advantage of Some property which the accompanying
sugar lacks.
(2) SUCROSE AND LACTOSE IN DAIRY PRODUCTS BY Two REDUC-
TION PROCESSES.—An interesting method for the simultaneous de-
termination of sucrose and lactose in Sweetened condensed milk and
ice cream has been described by White [19]. In outline, the clarified
solution is subjected to the Munson and Walker method of lactose
analysis and the copper referred to the appropriate column of lactose-
sucrose mixtures. The filtrate from the cuprous oxide, which is
then free from lactose, is collected quantitatively, acidified, and
heated to invert the sucrose, which is then determined in the form
of invert sugar by a second reducing-sugar analysis. Inasmuch as a
portion of the sucrose is destroyed during the lactose analysis, an
empirical correction is applied to the cuprous oxide precipitated by
invert sugar. The method is given in the following brief example:
Weigh 10 g of condensed milk (20 g of ice cream) into a 250-ml
volumetric flask and dissolve in 125 ml of boiling water. Mix for
3 minutes, cool to 20°C and add gradually 10 ml of Soxhlet copper-
sulfate solution and 6 ml of 0.5 N sodium hydroxide. Make to 1.5
ml over the mark (3.2 ml for ice cream) and filter.
Determine lactose in 50 ml of the filtrate by the Munson and
Walker method, using the “1 lactose—4 sucrose” column. Collect
the filtrate from the cuprous oxide precipitate in a 250-ml flask and
wash with 80 ml of hot water. Add 34 ml of 1+1 hydrochloric acid
and invert in a boiling water bath for 5 minutes. Cool and neutralize
with 50-percent sodium hydroxide. Determine invert sugar by
Munson and Walker method. Add 1.6 mg to the weight of cuprous
oxide (1.0 mg for ice cream). Refer both weights of copper to the
Munson and Walker table 78, p. 564.
4. DETERMINATION OF THREE SUGARS IN A MIXTURE
(a) GENERAL
The analysis of mixtures containing three sugars requires the ap-
plication of analytical processes which yield three equations. Special
methods in great variety have been brought into use for the analysis
of these complex products. The combinations of methods which
have proved most successful are those which include at least one
process which is selective for one of the constituent sugars. The
number and nature of the possible combinations of methods is large,
but for the present purpose it will suffice to illustrate the principles
by a few examples given in detail.
In a very few instances one equation can be evaluated for total
sugar in a mixture by using a physical method. Such a mixture can
consist solely of pure sugars, but it is of such infrequent occurrence
that the methods of analysis will not be described here. They can
be found in Browne's Handbook of Sugar Analysis [3].
(b) THREE SUGARS BY COMBINATION OF POLARIMETRIC AND REDUCTION
METHODS AND ONE SELECTIVE METHOD
Wherever this combination can be applied, it is the simplest method
of analysis of a complex mixture, involving as it does but three stand-
226 Circular of the National Bureau of Standards
ard operations. Thus for the analysis of a mixture of sucrose, dextrose,
and levulose, a direct and invert polarization and a reducing-sugar
analysis suffice for the completed determination.
The method is illustrated in the determination of the Browne
polarizing constants [2]. It would seem preferable to call them
“quotients” rather than “constants,” since the value of the quotient
is not constant but varies with the ratio of dextrose to levulose.
The Browne polarizing constants are defined by the expression
(S–P)/R, in which S and R are the percentages of sucrose and reduc-
ing sugar, respectively, and P is the direct polarization. Assume a
normal solution of a mixture of 99 percent of sucrose and 1 percent,
or 0.26 g, of invert sugar. The invert sugar will rotate — 1.19)(0.26=
—0.309. The value of the quotient is then 99–(99–0.309)|1=0.309.
Similarly, if the reducing sugar were 1 percent levulose, the quotient
would be 1.404, and if 1 percent dextrose, –0.806. At the ratio of
dextrose to levulose of about 64 to 36, the quotient becomes 0.
To calculate the percentages of dextrose and levulose, Browne used
the equations
a +ky= R
ca;+ cry-HS-P,
in which aſ and y are the percentages of dextrose and levulose, respec-
tively; k, the reducing ratio of levulose to dextrose; c, the polarizing
ratio of dextrose to sucrose at 20°C; c.1, the polarizing ratio of levulose
to sucrose; and R, the percentage of total reducing sugar, expressed
as dextrose (Allihn method).
Solving the equations for a and y,
cB+ S- P.
ly– percentage of levulose= kc–c
– U1
a = percentage of dextrose=R—ky.
Sucrose is estimated selectively by the Clerget method.
The numerical value of c is 52.74:66.5 = 0.793; that of c1,
–92.88:66.5= — 1.397. For k an average value of 0.915 is employed.
The method yields reliable results if the reducing-sugar content is
not too low. If S approaches closely to P, small errors in either
become large errors in their difference. It was, however, the only
practicable method previous to the introduction of the selective
method for levulose.
Zerban has shown the fair agreement of results obtained by this
method with those obtained by two selective analyses. The compara-
tive results are shown in table 30. The method of two selective
analyses, combined with the determination of total reducing sugar,
must be considered the more reliable procedure.
(c) THREE SUGARS BY COMBINATION OF TOTAL REDUCING POWER AND TWO
SELECTIVE METHODS
Mixtures of sucrose, dextrose, and levulose can be analyzed by a
Selective determination of sucrose by the Clerget method, a selective
determination of levulose by the Nyns method, and a determination of
total reducing sugar. Alternatively, a selective determination of dex-
trose by the iodine-alkali reaction can be used to replace the levulose
analysis, provided that adequate correction is applied for the action
of iodine on the nonaldose sugars.
Polarimetry, Saccharimetry, and the Sugars
227
TABLE 30.-Zerban analyses of deactrose and levulose in raw came sugar
Method I. Polarizing constants and total-reducing sugar
Method II. Total reducing sugar and Selective levulose analysis
Method I Method II
Sugar
Fi D%R2 PC3 R D%R PC4
SOME INDIVIDUAL SAMPLES
1. 55 55. 5 0. 181 1. 55 55. 7 (). 175
0. 73 47. 5 . 358 0. 73 44. 6 . 425
. 88 51. 5 . 273 . 88 51. () 273
1.03 56.2 . 166 1.03 54.8 . 195
0.94 65, 7 —. 043 0.94 59. 1 . 106
AVERA GE DEXTROSE-RATIO AND POLARIZING CONSTANTS
Cuba-------------------------------------|---------- 49. 0, 305 |---------- 47.8 (). 348
Puerto Rico.------------------------------|---------- 53, 7 . 221 ---------- 51.9 , 256
Santo Domingo---------------------------|---------- 45.8 . 394 ||---------- 49, 7 . 307
EHawaii- - — — I —- - - - - - - - - - 48.9 . 326 ---------- 48.0 349
Philippines---------------------------|---------- 49. • 317 ---------- 53.5 224
ANALYSES OF TWO PAIRS OF SU GARS
1, New crop - - - - - - - 0. 531 42.4 0. 471 0. 531 45, 6 0.395
1, Old Crop------------------------------- 1. 245 63. 1 . 016 1, 240 76. 5 —. 274
2, New crop - - - --- 0.431 42. 7 . 464 0.430 50.2 . 302
2, Old Crop------------------------------- .991 59.6 . 0.91 . 985 74. 5 —. 234
1 Percentage of total reducing Sugars found.
2 Percentage ratio of dextrose to total reducing Sugars.
3 Polarizing constant. -
4 Polarizing constant calculated from dextrose and levulose found.
(1) SUCROSE, DExTRose, AND LEVULOSE IN RAW SUGAR.—Zerban
and Wiley [20] have applied the method of two selective analyses to
the determination of sucrose, dextrose, and levulose in raw cane Sugar,
using for levulose the modification of Jackson and Mathews and for
sucrose the invertase Clerget analysis. For the determination of
total reducing sugar they used the Lane and Eynon volumetric
method, but since the original tables listed titers for dextrose, levulose,
and invert sugar only, they prepared interpolated tables for varying
ratios of these sugars in the presence of 10 and 25 g of sucrose, re-
spectively. In abbreviated form, these data are reproduced in tables
90 and 91, p. 596. Zerban and Wiley found slightly higher factors for
invert sugar than Iane and Eynon and recommend that the analyst
verify the published factors or establish his own. A similar recom-
mendation was made with respect to the Jackson-Mathews method.
They found that in order to obtain the same copper equivalents as
tabulated by these authors, they must conduct the reduction at 55.2°
C instead of 55.0° C, as specified. They determined the reduced
copper by ferric sulfate-permanganate titration.
The reducing power of dextrose (12.4 mg of dextrose= 1 mg of
levulose) determined by Jackson and Mathews was confirmed. Four
grams of sucrose reduced 8.5 mg of copper; 5 g, 9.0 mg; and 2 g, 5.7 mg.
Procedure.—Transfer a sample of raw sugar containing 62.5 g of
sucrose (determined by direct polarization) to a 250-ml flask, clarify
with neutral lead acetate, make to volume, and filter. Delead with
dry potassium oxalate. Determine (preferably in duplicate) apparent
228 Circular of the National Bureau of Standards
levulose in 20-ml portions by the Jackson-Mathews procedure, p. 203,
estimating copper by any desired method except that of direct weigh-
ing of the copper precipitate. Titrate the remainder of the solution
against 10 ml of Soxhlet solution. If the titer is less than 15 ml,
dilute 100 ml to 250 ml and repeat the titration. Determine the
sucrose by the invertase Clerget analysis.
The calculation of results, made by successive approximation, is
illustrated by an example. A sample, 64.60 g containing 62.5 g of
sucrose, gave a Lane and Eynon titer of 18.13 ml which, estimated as
invert sugar, indicated 239.4 mg of reducing sugars per 100 ml. By
the Jackson-Mathews method, 76.9 mg of reduced copper was found;
from which 9.0 mg is deducted to correct for the reducing action of 5 g
of sucrose. By table 93, p. 597, 67.9 mg corresponds to 22.0 mg of
apparent levulose in 20 ml of solution, or 110.0 mg in 100 ml.
Mg
Total reducing Sugars as invert_-- - - - - - - - - - - - - - - - - - - - - - - - 239. 4
Apparent levulose, first approximation - - - - - - - - - - - - - - - - - - - 110. 0
Apparent dextrose, first approximation, 239.4 – 110.0 - - - - - - 129. 4
Equivalent levulose, 129.4–4–12.4____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 10. 4
Apparent levulose, second approximation, 110.0- 10.4 - - - - - 99.6
Apparent dextrose, second approximation, 239.4–99.6- - - - - 139. 8
Equivalent levulose, 139.8--12.4-- - - - - - - - - - - - - - - - - - - - - - - 11. 3
Apparent levulose, third approximation, 110.0-11.3 - - - - - - 98. 7
Apparent dextrose, third approximation, 239.4–98.7 - - - - - - 140. 7
The levulose equivalent of the dextrose, 140.7–3–12.4, is again 11.3,
so that further approximation is unnecessary.
The ratio of levulose to dextrose is thus found to be 98.7 to 140.7,
or 41 to 59. From table 90, p. 596, the factor is 43.3, and total
reducing sugar, 238.8 in 100 ml. Calculated for original sample,
levulose is 0.382 percent; dextrose, 0.542 percent; and total reducing
sugar, 0.924 percent.
In a further study of raw-sugar analysis, Zerban [21] has compared
the Browne method of polarizing constants with the method of total
reducing sugar combined with selective methods for sucrose and
levulose. He devised a less laborious method of calculation than that
of successive approximations. Thus
aa;+y= R (57)
0.08062.--y= R1, (58)
in which aſ and y are the milligrams of dextrose and levulose, respec-
tively, in 100 ml of solution analyzed; R is milligrams of total sugars,
expressed as levulose by Lane and Eynon titration; and R1, the milli-
grams of apparent levulose determined by the Jackson-Mathews
method and corrected for the reducing effect of the sucrose. The
factor, 0.0806, is the constant reducing ratio of dextrose to levulose,
12.4 mg of dextrose having the same reducing effect as 1 mg of levulose.
Solution of eq 57 and 58 gives -
R—R1
a;=mg of dextrose in 100 ml of solution= a–0.0806
!y=mg of levulose in 100 ml of solution= R–air.
The calculation is facilitated by the factors in table 91, p. 596,
which is abbreviated from the expanded form given in the reference
cited. Interpolation yields the true factors accurately.
Polarimetry, Saccharimetry, and the Sugars 229
The simplified method of calculation is not as rigorous as the
method of successive approximations, but the errors for small per-
centages of total sugars are within the error of experiment. For
samples containing large amounts of reducing sugar in the presence
of small amounts of sucrose, the successive approximation method is
to be recommended.
The analytical procedure is described on page 227. Some typical
analyses of individual samples are shown in table 30, p. 227. In
table 30 are also given the averages of a large number of samples of
different geographical origin. Interesting analyses were made of two
pairs of samples produced from the same Cuban plantation in the crop
year 1934. The A samples were manufactured in 1934, the B samples
in 1935. In both cases the amount of total reducing sugars in the
old-crop samples is more than twice that in the new crop, and at the
same time the dextrose is very much higher. There is strong indication
that the old-crop sugars have undergone inversion during storage and
that levulose has been destroyed through the activity of torulas.
(2) SUCROSE, DEXTROSE, AND LEVULOSE IN CANE MOLASSES.–
Erb and Zerban [22] extended the work of the New York Sugar Trade
Laboratory to the determination of total reducing sugars, dextrose
and levulose, in cane molasses. Total reducing sugars were deter-
mined by the Munson and Walker method in samples containing 0.4 g
of total sugar. In amplification of the tables of Munson and Walker,
they determined the copper value of sucrose mixed with pure dextrose
and pure levulose, respectively, and also revised the tabulated values
of sucrose—invert-sugar mixtures, deriving the formulas
D=0.38476 CuO +0.00009436 CuO”—3.177,
L=0.4305 CuO +0.0000611 CuO°–3.412,
I=0.40016 CuO +0.00009631 CuO2–2.9911,
which are valid for 0.4 g of total sugar.
The revised values for invert sugar show, for concentrations of sugar
above 150 mg., slightly higher weights of sugar than those of Munson
and Walker for the same weights of copper.
For the analysis of molasses, total sugars were determined by the
Munson and Walker method, as described above, and levulose was
determined selectively in the same filtrate by the Jackson-Mathews
procedure, page 203.
The experimental data were solved for the respective figures by
substitution in the formulas
* R1–R.
D=º0.1
L=R1–a1),
the sucrose having been determined previously by the Clerget method.
R1, total reducing sugars, expressed as levulose (table 92, p. 597),
and R2, the apparent levulose (table 93, p. 597), after deducting from
the total copper precipitated the weight of copper reduced by the
sucrose, p. 227.
230 Circular of the National Bureau of Standards
These formulas are similar to those derived for the raw-sugar analy-
sis, but the a's now have different values because of the difference in
method of total reducing-sugar analysis. The solution of these
equations is greatly facilitated by use of the expanded table published
by the authors. Here it is possible to include the table only in greatly
abbreviated form, but interpolation yields correct figures for inter-
mediate values of CuO.
(d) ANALYSIS OF A MIXTURE OF THREE SUGARS BY THREE REDUCTION PROCESSES
(1) STEINHOFF METHOD For DExTRose, MALTOSE, AND DExTRIN
[23].—Steinhoff has based a proposed method for the simultaneous
determination of the three carbohydrates upon the assumption that all
dextrins in starch-conversion products are nonreducing toward Fehling
solution. In outline, he determined dextrose selectively by a modifica-
tion of the Barfoed method, total reducing sugar by Fehling solution
and total dextrose produced by complete hydrolysis of the mixture.
The required reagents consist of Soxhlet solutions I and II (p. 170),
and III, a 50-percent sodium-acetate solution. Prepare also 0.1 N
iodine and 0.1 N thiosulfate.
Weigh 8.75 g of commercial glucose sirup and make to 500 ml.
(Solution a). For complete hydrolysis, transfer 50 ml to a 100-ml
volumetric flask, add 25 ml of 3 N hydrochloric acid, and digest for
2% hours in a boiling-water bath. Cool, neutralize with sodium
hydroxide, and fill to mark. (Solution b). Reducing-sugar analysis
is carried out in three 200-ml Erlenmeyer flasks.
Analysis A.—For selective dextrose analysis take 10 ml of Soxhlet
solution I, 20 ml of solution III (sodium acetate), 10 ml of water, and
10 ml of solution a.
Analysis B.-For total dextrose and maltose, take 10 ml each of
Soxhlet solutions I and II, 20 ml of water, and 10 ml of solution a.
Analysis C.—For total sugar in the hydrolyzed solution take 10
ml each of Soxhlet solutions I and II, 20 ml of water, and 10 ml of
solution b. This aliquot sample contains half as much of the original
sample as analyses A and B. Hence the dextrose observed is multi-
plied by 2 to correspond with that derived from a 175-mg aliquot.
All three flasks are brought to boiling and ebullition is continued
for 2 minutes, or preferably allowed to stand in a boiling water bath
for 20 minutes. Dissolve the cuprous oxide precipitate in hydrochlo-
ric acid, neutralizing the excess acid with sodium bicarbonate. Meas-
ure in an excess of 0.1 Niodine, and after cooling the solution, titrate
the excess of iodine with thiosulfate. Calculate the number of milli-
liters of 0.1 Niodine consumed.
For the calculation of the results
Percentage of dextrose=''}}
Percentage of maltose="#.
Percentage of dextrin="##! –M),
Polarimetry, Saccharimetry, and the Sugars 231
in which D is the weight of dextrose found by analysis A when referred
to column 1 of table 104, p. 609; M is the weight of maltose which
corresponds to the milliliters of 0.1 Niodine which is obtained if the
volume used in analysis A but calculated to Fehling solution by
column 2 is deducted from the volume of iodine consumed in analysis
B. T is the weight of total dextrose corresponding to the volume of
iodine consumed in analysis C; and W is the weight in milligrams in
the respective aliquot samples, that is, 175 mg.
Eacample.—8.75 g of a glucose sirup was analyzed as described above.
Analysis A.—9.17 ml of 0.1 N iodine was consumed. The aliquot contained
175 mg of the original sample. The 9.17 ml corresponds to 26.25 mg of dextrose.
100X26.25_ t
175 = 15 percent.
Analysis B.—16.60 ml of iodine was consumed. According to the table, 9.17
ml of iodine (analysis A) is equivalent to 8.24 ml when the analysis is carried out
by the Soxhlet reagents. Hence, by deducting the reduction by dextrose, 16.60–
8.24= 8.36, we obtain the reduction caused by maltose. This volume of iodine
corresponds to 45.5 mg of maltose by column 3
100 × 45.5
175
Analysis C.—21.56 ml of iodine was consumed by a sample half as great as in
the preceding analysis. This corresponds, by column 4, to 72.82 mg of dextrose,
which, multiplied by 2, equals 145.64 mg from a 175-mg sample. Deduct the
dextrose and maltose already present before hydrolysis, that is, 26.25-H 45.5=
Dextrose =
Maltose = = 26 percent.
71.75.
Dextrin _90 dº; 71.75) =38 percent.
O
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[2] C. A. Browne, J. Am. Chem. Soc. 28, 439 (1906).
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[4] O. Gubbe, Ber. deut. chem. Ges. 18, 2207 (1885).
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]
}
[
[1
[1
| 1
tº-
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ſ
[14] D. R. Nanji, F. T. Paton, and A. R. Ling, J. Soc. Chem. Ind. 44, 253T (1925).
[15] C. A. Browne and M. Phillips, Int. Sugar J. 41, 430 (1939).
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[17] K. V. Lefèvre and B. Tollens, Ber. deut. chem. Ges. 40, 4513 (1907).
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[20] F. W. Zerban and M. A. Wiley, Ind. Eng. Chem., Anal. Ed. 6, 354 (1934).
[21] F. W. Zerban, Ind. Eng. Chem., Anal. Ed. 8, 321 (1936).
[22] C. Erb and F. W. Zerban, Ind. Eng. Chem., Anal. Ed. 10, 246 (1938).
[23] G. Steinhoff, Z. Spiritusind. 56, 64 (1933). -
232 Circular of the National Bureau of Standards
XI. ANALYSIS OF SPECIAL PRODUCTS
1. HONEY [14]
(a) PREPARATION OF SAMPLE
(1) LIQUID OR STRAINED HONEY. —If the sample is free from granu-
lation, mix it thoroughly by stirring or shaking before weighing por-
tions for the analytical determination. If the honey is granulated,
place the container, having the stopper loose, in a water bath and
heat at a temperature not exceeding 50° C, with occasional stirring
until the sugar crystals dissolve. Mix thoroughly, cool, and weigh
portions for the analytical determinations. If foreign matter, such
as wax, sticks, bees, particles of comb, etc., is present, heat the sample
to 40° C in a water bath and strain through cheesecloth in a hot-
water funnel before weighing portions for analysis.
(2) CoMB HoNEY.-Cut across the top of the comb, if sealed, and
separate completely from the comb by straining through a 40-mesh
sieve. When portions of the comb or wax pass through the sieve, heat
the sample as in (1) and strain through cloth. If the honey is granu-
lated in the comb, heat until the wax is liquefied; stir, cool, and remove
the wax.
(b) MOISTURE
Proceed as directed under (c), page 262 of this circular.
(c) ASH
Weigh 5 to 10 g of honey into a platinum dish, add a few drops of
pure olive oil to prevent spattering, heat carefully until swelling ceases,
and ignite at a temperature not above dull redness until a white ash
is obtained.
(d) DIRECT POLARIZATION.—TENTATIVE
(1) IMMEDIATE DIRECT Pola RIZATION.—Transfer 26 g of the honey
to a 100-ml flask with water, add 5 ml of alumina cream, dilute to the
º: with water at 20°C, filter, and polarize immediately in a 200-mm
tube.
(2) ConstANT DIRECT POLARIZATION.—Complete the mutarota-
tion by allowing the solution prepared for polarization to stand over-
night before making the reading or by adding a few drops of NH4OH
to the solution before making to volume. If necessary to conserve
the sample, the solution from the tube used in the immediate direct
polarization (1) may be returned to the flask. Make the final reading
at 20°C in a 200-mm tube.
(3) MuTAROTATION.—The difference between (1) and (2) is a
measure of the mutarotation.
(4) DIRECT Pola RIZATION AT 87°C.—Polarize the solution obtained
º: (2) at 87° C in a jacketed 200-mm metal tube, preferably of
SLIVOI’.
(e) INVERT POLARIZATION.—TENTATIVE
(1) AT 20° C.—Invert 50 ml of the solution obtained under (d),
using either invertase or hydrochloric acid as directed on pages 157-58,
or page 155 this Circular, and polarize at 20°C in a 200-mm tube.
(2) AT 87° C.—Polarize the solution obtained under (1) at 87° C
in a 200-mm tube.
Polarimetry, Saccharimetry, and the Sugars 233
(f) REDUCING SUGARS
Dilute 10 ml of the solution used for direct polarization (d) to
250 ml and determine reducing sugars in 25 ml of this solution by
Lane-Eynon method, p. 185, or by the Munson-Walker method,
p. 170, of this Circular. Calculate the result to percentage of invert
Sugar.
(g) SUCROSE
(a) Calculate from the data given in (d) (2) and (e) (1) if inversion
is made by invertase, as directed on page 157. Use the formula
given on page 158.
Figure 40.-Apparatus for high-temperature polarization.
(h) LEVULOSE—TENTATIVE
Multiply the direct reading at 87°C, (d) (4), by 1.0315, and sub-
tract the product from the constant direct polarization at 20° C,
(d) (2); divide the difference by 2.3919 to obtain grams of levulose
in a normal weight of honey. From this figure calculate the percentage
of levulose in the original sample.
(i) DEXTROSE—TENTATIVE
Multiply the percentage of levulose (h) by the factor 0.915, which
gives its dextrose equivalent in copper-reducing power. Subtract
the figure obtained from that of the reducing sugars (f), calculated as
dextrose, to obtain the dextrose in the sample. Because of the differ-
ence in the reducing powers of the different sugars, the sum of the
dextrose thus found and the levulose as obtained under (h) will be
greater than the quantity of invert sugar obtained under (f).

234 Circular of the National Bureau of Standards
(j) DEXTRIN (APPROXIMATE)—TENTATIVE
Using not more than 4 ml of water, transfer 8 g of the sample (4 g in
the case of dark-colored honeydew honey) to a 100-ml flask by allow-
ing the sample to drain from the weighing dish into the flask and then
dissolving the residue in 2 ml of water. After adding this solution to
the contents of the flask, rinse the weighing dish with two 1-ml portions
of water, adding a few milliliters of absolute alcohol each time before
decanting. Fill the flask to the mark with absolute alcohol, shaking
constantly. Set the flask aside until the dextrin has collected on the
sides and bottom and the liquid is clear. Decant the clear liquid
through a filter paper, and wash the residue in the flask with 10 ml of
95-percent alcohol, pouring the washings through the same filter.
Dissolve the dextrin in the flask with boiling water and filter through
the filter paper already used, receiving the filtrate in a weighed dish
prepared as directed on page 262, (c). Rinse the flask and wash the
filter a number of times with small portions of hot water, evaporate on
a water bath, and dry to constant weight at 70° C under a pressure of
not more than 50 mm of mercury.
After determining the weight of the alcohol precipitate, dissolve the
latter in water and make up to definite volume, using 50 ml of water for
each 0.5g of precipitate or part thereof.
Determine reducing sugars in the solution both before and after
inversion by the method of Munson and Walker, p. 170, expressing
the results as invert sugar. Calculate sucrose from the results thus
obtained, and subtract the sum of the reducing sugars before inversion
and sucrose from the weight of the total alcohol precipitate to obtain
the weight of the dextrin.
(k) FREE ACID
Dissolve 10 g of the honey in water and titrate with 0.1 N NaOH
solution, using phenolphthalein indicator. Express the results in
terms of milliliters of 0.1 N NaOH required to neutralize 100 g of the
sample.
(1) COMMERCIAL GLUCOSE
(1) QUALITATIVE TEST-TENTATIVE.-Dilute the honey with water
in the proportion of 1:1 and add a few milliliters of iodine solution (1 g
of I, 3 g of KI, 50 ml of water). In the presence of commercial glucose
the solution turns red or violet, the depth and character of the color
depending upon the quality and nature of the glucose used. A blank
test with a pure honey of about the same color should be made in
order to secure an accurate color comparison. Should the honey
be dark and the percentage of glucose very small, precipitate the dex-
trin that may be present by adding several volumes of 95-percent
alcohol. Allow to stand until the precipitate settles (do not filter),
decant the liquid, dissolve the residue of dextrins in hot water, cool,
and apply the above test to this solution. A negative result is not
proof of the absence of commercial glucose, as some glucose, especially
of high conversion, does not give reaction with I. [2]
(2) QUANTITATIVE METHOD–TENTATIVE.-An approximate deter-
mination can be made by Browne's formula as follows: Multiply the
difference in the polarizations of the invert solution at 20° and 87°C,
(e) (1) and (e) (2), p. 232, by 77, and divide this product by the
percentage of invert sugar found in the sample after inversion. Mul-
Polarimetry, Saccharimetry, and the Sugars 235
tiply the quotient by 100 and divide the product by 26.7 to obtain the
percentage of honey in the sample; 100 percent minus the percentage
of honey gives the percentage of glucose. [2]
(m) COMMERCIAL INVERT SUGAR [3]
(1) RESORCINOL TEST [4]—TENTATIVE.
a. Resorcinol solution.—Dissolve 1 g of resublimed resorcinol in 100
ml of HCl (sp gr 1.18 to 1.19).
b. Determination.—Introduce 10 ml of a 50-percent-honey solution
into a test tube and add 5 ml of ether. Shake gently and allow to stand
for some time until the ether layer is clear. Transfer 2 ml of this clear
ether solution to a small test tube and add a large drop of the recently
prepared resorcinol solution. Shake, and note the color immediately.
A cherry-red color appearing at once indicates the presence of commer-
cial invert sugar. Yellow to salmon shades have no significance.
(2) ANILINE CHLORIDE TEST [5]—TENTATIVE.
a. Reagent.—Aniline chloride solution.—To 100 ml of chemically
pure aniline add 30 ml of 25-percent HCl.
b. Determination.—Introduce 5 g of the honey into a porcelain dish
and add, while stirring, 2.5 ml of the recently prepared aniline reagent.
In the presence of commercial invert sugar, the reagent assumes
immediately an orange-red color turning dark red. Yellow to salmon
shades have no significance.
The resorcinol test and the aniline-chloride test, when negative,
may not be regarded as conclusive evidence of the absence of commer-
cial invert-sugar sirup in honey.
(n) DIASTASE [6]—TENTATIVE
Mix 1 part of honey with 2 parts of sterile water. Treat 10 ml
of this solution with 1 ml of 1-percent soluble starch solution and
digest at 45°C for an hour. At the end of this time test the mixture
with 1 ml of iodine solution (1 g of I, 2 g of KI, 300 ml of water).
Treat another 10 ml portion of the honey solution, mixed with 1 ml
of the soluble starch solution without heating to 45° C, with the re-
agent and compare the colors produced. If the original honey has
not been heated sufficiently to destroy the diastase, an olive green or
brown coloration will be produced in the mixture that has been heated
at 45° C. Heated or artificial honey becomes blue.
2. MAPLE PRODUCTS [7, 14]
(a) PREPARATION OF SAMPLE
(1) SIRUP.
For solids determination.—-If the sample contains no sugar crystals
or suspended matter, decant sufficient of the clear sirup for use in the
determination. If sugar crystals are present, redissolve them by
heating. If suspended matter is present, filter the sample through
cotton wool.
For other determinations.—If sugar crystals are present, redissolve
them by heating. If other sediment is present, distribute it evenly
through the sirup by shaking. Transfer approximately 100 ml of the
sirup, with its suspended sediment, to a casserole or beaker, add
one-quarter the volume of water and evaporate over a flame. When
the temperature of the boiling sirup approaches 104°C, draw a small
236 Circular of the National Bureau of Standards
quantity into a thin-walled pipette of about 1-ml capacity, and cool to
room temperature in running water. Wipe the outside of the pipette,
allow the possibly diluted sirup in the point to escape, and make a
refractometric measurement of the solids content of the cooled sirup.
Repeat this procedure from time to time until a reading is obtained
corresponding to 64.5-percent solids (n20=1.4521), or to such other
value as, in the experience of the analyst, will give a filtered sirup of
65.0-percent solids. Filter the sirup through a filter which will allow
the 100 ml to pass within 5 minutes and adjust the filtrate to 65.0+0.5-
percent solids (refractometric) by thorough mixing with the appropri-
ate quantity of water.
(2) SUGAR AND OTHER SOLID AND SEMIsol1D PRODUCTs—TENTA-
TIVE.
For moisture and solids determination.—Grind in a mortar, if neces-
sary, and mix thoroughly.
For other determinations.—Prepare a sirup by dissolving approxi-
mately 100 g of the sample in 150 ml of hot water, boil until the
temperature approaches 104°C and complete the preparation of the
resulting sirup as directed under (1), commencing at “draw a small
amount into a thin-walled pipette.”
(b) MOISTURE OR SOLIDS
(1) MAPLE SUGAR.—Proceed as directed under (b), p. 262.
(2) MAPLE SIRUP, MAPLE CREAM, ETC.–Proceed as directed under
(c), p. 262, using a sample prepared as directed under (a) (1) p. 235.
The determination may be made by means of the refractometer, as
directed on page 258.
(c) ASH
Proceed as directed on page 264.
(d) POLARIZATION
(1) DIRECT Pola RIZATION.—Proceed as directed on page 157.
(2) INVERT Pola RIZATION.
At 20° C.–Proceed as directed on page 155 or 157, after clarifi-
cation with a minimum amount of basic lead acetate and t e removal
of the excess lead in the filtrate by anhydrous sodium carbonate.
At 87° C.—Polarize the solution obtained under (d) (1), at 87° C
in a 200-mm tube.
(e) SUCROSE—POLARIMETRIC METHOD
Calculate from the results of (d) (1) and (d) (2), using the appro-
priate formula, page 156 or page 158.
(f) SUCROSE—CHEMICAL METHOD
By reducing Sugars before and after inversion.—Determine the reduc-
ing sugars (clarification having been effected with neutral lead acetate,
never with basic lead acetate) as directed on page 170, and calculate
them to invert sugar from table 78, p. 564. Invert the solution as
directed under (1), p. 156, exactly neutralize the acid, and again
determine the reducing sugars, but calculate them to invert sugar
from the table referred to above, using the invert column alone.
Deduct the percentage of invert sugar obtained before inversion from
Polarimetry, Saccharimetry, and the Sugars 237
that obtained after inversion and multiply the difference by 0.95 to
obtain the percntage of sucrose. The solutions should be diluted in
both determinations so that not more than 240 mg of invert sugar is
present in the aliquot taken for reduction. It is important that all
lead be removed from the solution with anhydrous powdered potassium
oxalate or NagcO3 before reduction.
(g) REDUCING SUGARS AS INVERT SUGAR
(1) BEFORE INVERSION.—Proceed, as directed under 2 (a)(2), p. 170,
on aliquots of the solution used for direct polarization, (d) (1), p. 236.
(2) AFTER INVERSION.—Proceed, as directed under (1), on aliquots
of the solution used for invert polarization, (d) (2), p. 236.
(h) COMMERCIAL GLUCOSE [8]
(1) SUBSTANCEs CoNTAINING LITTLE or No INVERT SUGAR.—
Commercial glucose cannot be determined accurately owing to the
varying quantities of dextrin, maltose, and dextrose present in the
product. However, in sirups in which the quantity of invert sugas
is so small as not to affect appreciably the result, commercial glucose
may be estimated approximately by the following formula:
(a—S)100
G=*†,
in which
G= percentage of commercial glucose solids,
a = direct polarization, normal solution, and
S=percentage of cane sugar.
Express the results in terms of commercial glucose solids polarizing
+211° S. (This result may be recalculated in terms of commercial
glucose of any Baumé reading desired.)
(2) SUBSTANCEs ContAINING INVERT SUGAR.—Prepare an inverted
half-normal solution of the substance as directed on page 156; cool
the solution after inversion, make neutral to phenolphthalein with
NaOH solution, slightly acidify with HCl (1+5) and treat with 5 to
10 ml of alumina cream before making up to the mark. Filter, and
polarize at 87° C in a 200-mm jacketed tube. Multiply the reading
by 200 and divide by the factor 196 to obtain the quantity of commer-
cial glucose solids polarizing +21.1° W. (This result may be recal-
culated in terms of commercial glucose of any Baumé reading desired.)
(i) LEAD NUMBER
(1) CANADIAN LEAD NUMBER [9] (Fow LER MoDIFICATION).
Reagent—Standard basic lead acetate solution.—Activate litharge by
heating it to 650 to 670° C for 2% to 3 hours in a muffle. (The cooled
product should be lemon color.) In a 500-ml Erlenmeyer flask pro-
vided with a return condenser, boil 80 g of normal Pb acetate crystals
and 40 g of the freshly activated litharge with 250 g of water for 45
minutes. Cool, filter off any residue, and dilute with recently boiled
water to a density of 1.25 at 20° C.
Determination.—Weigh the quantity of sirup containing 25 g of
dry matter, transfer to a 100-ml flask, and make up to mark at 20°C,
or use the solution in which the conductivity value has been determined
323414°–42——17
238 Circular of the National Bureau of Standards
(j). Pipette 20 ml into a large test tube, add 2 ml of the standard
basic Pb acetate solution, cork, and allow to stand for 2 hours.
Filter with suction on a 25-ml tared Gooch having an asbestos mat
at least 3 mm thick. When nearly all the liquid has run through, fill
the crucible with cold water. Repeat to a total of four washings,
taking care to prevent formation of fissures in the precipitate by
keeping it covered with water and avoiding too great suction. Dry
at 100°C, weigh, and multiply the weight by 20.
(2) WINTON LEAD NUMBER [10].
Reagent—Standard basic lead acetate solution.—To a measured volume
of the reagent prepared for determination of the Canadian lead num-
ber (1) add 4 volumes of water, and filter. A blank should be run
with each set of determinations.
Determination of lead in the blank.-Transfer 25 ml of the standard
basic Pb acetate to a 100-ml flask, add a few drops of glacial acetic
acid, and make up to the mark with water. Shake, and determine
PbSO, in 10 ml of the solution, as directed below. The use of acetic
acid is imperative in order to retain all Pb in solution when the reagent
is diluted with water.
Determination.—Transfer 25 g of the sample to a 100-ml flask by
means of water. Add 25 ml of the standard basic Pb acetate solution
and shake. Fill to the mark, shake, and allow to stand for at least
3 hours before filtering. Pipette 10 ml of the clear filtrate into a
250-ml beaker, add 40 ml of water and 1 ml of H2SO4, shake, and add
100 ml of 95-percent alcohol, dry in a water oven, and ignite in a
muffle or over a Bunsen burner, applying the heat gradually at first
and avoiding a reducing flame. Cool and weigh. Subtract the
weight of PbSO, so found from the weight of PbSO, found in the
blank, and multiply by the factor 27.33. The use of this factor gives
the Pb number directly, without the various calculations otherwise
required.
(j) CONDUCTIVITY VALUE [11]
(1) APPARATUs.
Conductivity cell.—Should be made of resistance glass with plati-
nized Pt electrodes firmly fixed and adequately protected from dis-
placement. These electrodes may be sealed in a vessel into which
the solution under examination may be run and subsequently drawn
off (Zerban type), or attached to a support so that they can be low-
ered into a cylinder (or a 100-ml beaker) containing the solution
(dipping type). The cell must be provided with a thermometer
graduated in tenths of a degree over the range 20 ° to 30 ° C,
and the bulb must be placed in the immediate vicinity of the elec-
trodes. The cell constant should be approximately 0.15.
Galvanometer or a microphone hummer (or an induction coil) and a
sensitive telephone receiver.
Suitable source of current.—Dry or storage cells if a hummer or
ºn coil is used; 110-volt alternating current if a galvanometer
1S U186O1.
Resistances of 10 and 100 ohms.-Should be fixed and accurate.
Slide wire or Wheatstome bridge.
Device for control of the temperature of the cell to within +0.1° C.—
This may consist of a thermostat or a vessel into which water of suit-
able temperature may be run to adjust the cell contents to 25 °C.
Polarimetry, Saccharimetry, and the Sugars 239
(2) DETERMINATION OF THE CELL CONSTANT.-Prepare solutions
of 0.3728 and 0.7456 g of dry KCl in water, which offers a resistance
of at least 25,000 ohms in the cell, and make them to the mark at
20° to 25° C in 500-ml volumetric flasks. Fill the cell with the
more dilute (0.01 M) solution, adjust to 25° -- 0.1°C, measure the
electrical resistance, and multiply the number of ohms by 141.2.
Rinse with the stronger (0.02 M) solution, fill the cell with the solu-
tion, measure its resistance at 25°C, and multiply by 276.1. Average
the two results.
(3) DETERMINATION.—Weigh out a quantity of sirup that contains
25 g of dry matter, transfer to a 100-ml volumetric flask with warm
water of the same quality as that used in the determination of the
cell constant, cool to 25°C, make to mark, and measure the resist-
ance in the cell at 25° -- 0.1° C. Divide the cell constant by the
number of ohms found.
(k) MALIC-ACID VALUE (COWLES) [12]—TENTATIVE
Weigh 6.7 g of the sample into a 200-ml beaker; add 5 ml of water,
then 2 ml of a 10-percent calcium acetate solution; and stir. Add,
gradually and with constant stirring, 100 ml of 95-percent alcohol
and agitate the solution until the precipitate settles, or let stand
until the supernatant liquid is clear. Filter off the precipitate and
wash with 75 ml of alcohol, 85 percent by volume. Dry the filter
paper and ignite in a platinum dish. Add 10 ml of 0.1 N HCl, and
warm gently until all of the lime dissolves. Cool, and titrate back
with 0.1 N NaOH solution, using methyl orange indicator. The
difference in milliliters divided by 10 represents the malic-acid value
of the sample. Previous to use, the reagents should be tested by a
blank determination and any necessary corrections applied.
3. DETERMINATION OF SUGARS IN MILK PRODUCTS
The estimation of lactose in fresh milk is, from the standpoint of
sugar analysis, relatively simple, but the preparation of the sample
for analysis involves procedures regarding which there is much dis-
pute. The Association of Official Agricultural Chemists finds it
satisfactory to clarify with copper sulfate in preparation for reducing-
sugar analysis or with mercuric nitrate for polariscopic analysis. On
the other hand, the British Subcommittee on Milk Products recom-
mends the use of zinc ferrocyanide, prepared in the presence of the
sample, but permits the use of phosphotungstic acid. The volume of
the precipitate is relatively large and must be calculated or
determined.
An important commodity is condensed milk sweetened with Su-
crose. Occasionally the sucrose is partially inverted by the action of
enzymes or microorganisms, and in some instances further action of
microorganisms converts the levulose so formed into a nonreducing
levan. In some cases, other sugars may be added as sweetening
agents. The analysis of such sugar mixtures becomes an intricate
problem.
Many of the methods for the sugar mixtures in milk products have
been elaborated solely for the purposes of milk analysis, but appear
to be capable of general application to other products.
240 Circular of the National Bureau of Standards
(a) DETERMINATION OF THE VOLUME OF THE PRECIPITATE
If the percentages of fat and protein of a milk product are known,
the volume of the clarification precipitate can be calculated with fair
approximation by the method of the British Subcommittee on Milk
Products [13]. The volume of the protein precipitate varies with
the nature of the precipitant. For phosphotungstic acid clarification
the specific volume of fat is 1.08 and for protein, 0.74. The volume
then is fat).{1.08+ protein X 0.74, to which is added a further empirical
correction of 1.5 ml.
For the zinc ferrocyanide method the volume of precipitate is about
double that for the phosphotungstic acid precipitate. The volume of
precipitate is then fat).{1.08-|-protein X1.55. The British subcom-
mittee, however, recommends actual determination of the volume of
the precipitate for each sample [13].
(1) Weigh 100 g of milk into a 200-ml flask. Add precipitating
reagents, make up to the mark at 20°C, filter, and polarize at 20° C.
Reading=A.
(2) Weigh 100 g of the same milk and 16.8 g of sucrose into a 200-ml
flask, dissolve the sugar, add precipitating reagents, make up to the
mark at 20°C, filter, and polarize at 20° C. Reading=B.
(3) Weigh 140 g of the same milk into a 200-ml flask and add
Seven-fifths of the previous quantities of precipitating reagents. Make
up to the mark at 20°C, and filter. Take 70 ml of the filtrate, make
up to 100 ml, and polarize at 20° C. Reading=C.
(4) Measure 70 ml of the filtrate from (3) into a 100-ml flask, add
8.4 g of sucrose, dissolve, make up to the mark at 20°C, and polariez
at 20° C. Reading=D.
The correction for volume of precipitate for 100 g of milk
D—C
–200(1-#%
)-milliters.
(b) LACTOSE IN MILK [14]
(1) OPTICAL METHOD.
Reagents.-(a) Acid mercuric nitrate solution.—Dissolve mercury in
twice its weight of concentrated nitric acid and dilute with an equal
volume of water.
(b) Mercuric iodide solution.—Dissolve 33.2 g of KI and 13.5 g of
HgCl2 in 200 ml of glacial acetic acid and 640 ml of water.
Determination.—Determine the specific gravity (20°/20°) of the
milk and place in a flask graduated at 102.6 ml, the volume of milk
indicated in table 31. Add 1 ml of solution (a) or 30 m) of solution (b),
fill to the mark, shake frequently for at least 15 minutes, filter through
a dry filter, and polarize. The volumes in the table are those of a
double-normal weight of lactose (32.9 g per 100 ml); hence, if a 200-ml
tube is used, divide the saccharimeter reading by 2 to obtain the
percentage of lactose in the sample.
(2) CHEMICAL METHoD.—Dilute 25 g of the sample with 400 ml of
water in a 500-ml volumetric flask and add 10 ml of CuSO4 solution
(Soxhlet solution 1) and about 7.5 ml of a KOH solution of such strength
that 1 volume is just sufficient to precipitate completely the copper as
hydroxide from 1 volume of the copper sulfate solution. (Instead, 8.8
ml of 0.5 N NaOH solution may be used). After the addition of the
alkali Solution, the mixture must still have an acid reaction and con-
Polarimetry, Saccharimetry, and the Sugars 241
TABLE 31.-Volume of milk corresponding to lactose double-normal weight
Yº: of Volume of
St Mar, ific, Imilk for a S 1 avoi fir, Imilk for a
jº lactose º lactose
normal normal .
weight weight
nl ml
1. ()24 64. 25 1. 030 63.90
1. ()25 64. 20 1.031 63. 8()
1. ()26 64. 15 1. 032 ($3.75
1.027 64. 05 1.033 63. 7()
1.028 64. 00 1.034 63. 65
1. 029 63.95 1. 035 63. 55
1.036 63. 50
tain copper in solution. Fill the flask to the 500-ml mark, mix, filter
through a dry filter, and determine lactose in an aliquot of the filtrate
by the Lane and Eynon or Munson and Walker method.
4. REFERENCES
[1] U. S. Dept. Agri., Bur. Chem. Bul. 110 (1908) and 154 (1912); Z. Nahr.
Genussm. 18, 625 (1909).
[2] U. S. Dept. Agr., Bur. Chem. Bul. 110, 60 (1908).
[3] U. S. Dept. Agri., Bur. Chem. Bul. 110 (1908) and 154 (1912).
[4] U. S. Dept. Agri., Bur. Chem. Bul. 154, 15 (1912); J. Ind. Eng. Chem. 17,
612 (1925); J. Assn. Official Agr. Chem. 15, 78 (1932).
5] Z. Nahr. Genussm. 22, 412 (1911).
6] Z. Nahr. Genussm. 19, 72 (1910).
7] J. Hortvet, J. Am. Chem. Soc. 26, 1523 (1904); J. Assn. Official Agr. Chem.
15, 79 (1932); 16, 79 (1933); 17, 73 (1934); 18, 83 (1935).
[8] A. E. Leach and A. L. Winton, Food Inspection and Analysis, 4th ed., p. 652
(John Wiley & Sons, Inc., N. Y., 1920).
[9] J. § jº, J. Assn. Official Agr. Chem. 4, 437 (1921); 16, 80 (1933); 17, 74
1934).
[10] A. L. Winton and J. L. Kreider, J. Am. Chem. Soc. 28, 1204 (1906); J. Official
Agr. Chem. 16, 80 (1933); 17, 74 (1934).
11] C. A. Browne, J. Am. Chem. Soc. 28, 435 (1906); J. Assn. Official Agr.
|
|
|
ſ
[
[
[
Chem. 16, 80 (1933); 17, 74 (1934).
[12] H. W. Cowles, Jr., J. Am. Chem. Soc. 30, 1285 (1908).
[13] Analyst 55, 116 (1930).
[14] Methods of Analysis of the Association of Official Agr. Chem., 5th ed. (1940).
XII. DETERMINATION OF PENTOSANS
1. DESCRIPTIVE
Pentosans are polysaccharides that yield pentoses upon hydrolysis.
As their names imply, araban is thus related to arabinose, and xylan
to xylose. The determination of pentosans depends upon their
conversion into furfural and the subsequent determination of the
furfural. The following reactions are assumed to take place:
+ H5O —3H2O
C5HsO4–C5H10O3 — CŞIH4O2
Pentosan Pentose Furfural
In carrying out pentosan determinations, one is therefore concerned
with the quantitative conversion of the pentosan into furfural and the
subsequent determination of the furfural.
The method universally adopted for converting pentosans into
furfural consists in boiling the substance with 12-percent hydro-
242 Circular of the National Bureau of Standards
chloric acid and collecting the distillate at the rate of 30 ml per 10
minutes. The quantity of distillate collected in some procedures is
arbitrarily defined, while in others the distillation is continued until
furfural ceases to come over, as indicated by the aniline acetate test."
Methylfurfural gives only a faint-yellow color with aniline acetate.
A solution of aniline in alcohol is used to test for this substance.
Furfural and hydroxyfurfural derivatives are very sensitive to the
aniline alcohol reagent, giving a bright-red color.
Jolles [1] employed steam distillation in order to remove the fur-
fural from the acid solution more rapidly and reported quantitative
conversion of arabinose and xylose into furfural. Pervier and Gortner
[2] found that steam distillation from a 12-percent hydrochloric acid
solution as used by Jolles, or from an 18- to 20-percent hydrochloric
acid solution (the acid percentage being indicated by the boiling
point), resulted in quantitative yields of furfural from arabinose and
xylose. They also concluded that the rate of distillation did not
affect the yield, and thus a slow current of steam was sufficient to
sweep out the furfural as fast as it was formed from the pentose.
When the usual method of distillation from 12-percent hydrochloric
acid was used, these authors obtained a 95.3-percent yield of furfural
from arabinose and 96.1-percent yield from xylose. These figures are
approximately 7 percent higher than those generally obtained.
Kline and Acree [3] concluded that steam distillation gave no better
yields of furfural from xylose than did the usual method of distillation.
Kullgren and Tydén [4] converted pentosans to furfural by distilling
from a 13.15-percent hydrochloric acid solution saturated with
sodium chloride. They thus had a constant acid concentration in the
distilling flask.
Hughes and Acree [5] reported that a rapid steam distillation from a
12-percent hydrochloric acid solution saturated with sodium chloride
gave quantitative yields of furfural from xylose as compared with
96-percent yields when a slow current of steam was used, irrespective
of whether or not the solution was saturated with sodium chloride.
The gravimetric methods for the determination of furfural include
the use of phloroglucin [6], barbituric acid [7], thiobarbituric acid [8],
and diphenyl thiobarbituric acid [9]. The phloroglucin method has
been carefully studied and generally adopted.
The volumetric methods include the use of phenylhydrazine
[10], potassium bisulfite [1], and potassium bromate-bromide solution.
The latter was studied by Pervier and Gortner [2]. They used an
electrometric titration method and found that under their experi-
mental conditions the potassium bromate and furfural reacted in
the molecular ratio 1:3. Powell and Whittaker [11] determined the
amount of bromine absorbed by a back-titration method, using
potassium iodide and sodium thiosulfate. Under their experimental
conditions they found that 4 atoms of bromine reacted with 1 molecule
of furfural. In 1933, Magistad [12] pointed out that the furfural-
bromate reaction is influenced greatly by temperature. Hughes
and Acree [13] carried out the reaction at 0°C. By carefully con-
trolling the temperature and time of reaction, they obtained reproduc-
!! The aniline acetate reagent is prepared by shaking equal volumes of aniline and water in a test tube
and adding glacial acetic acid until the solution is clear. Place a drop of the reagent on a filter paper and
allow a drop of the distillate to spread into the reagent. If furfural is present, a red color will appear where
the circles intersect. Toward the end of the distillation the red line will appear only after drying.
Polarimetry, Saccharimetry, and the Sugars 243
ible results in which 1 mole of bromine reacted with 1 mole of fur-
fural. Kullgren and Tydén employed a potassium bromate-bromide
solution, which they added at a temperature of 18° to 19°C, together
with 10 ml. of ammonium molybdate. In 0 to 4 minutes a yellow
color developed, and the reaction was allowed to run exactly 4 minutes
after this coloration appeared. It will be noted that the bromine
reaction with furfural takes place in two distinct stages. One mole
of bromine reacts with furfural very rapidly and then another mole is
slowly absorbed. Powell and Whittaker allowed their reaction mix-
ture to stand 1 hour, under which condition more than 1 mole of
bromine reacts with a mole of furfural.
During the distillation of plant products with hydrochloric acid,
along with the furfural are formed other substances which react with
phloroglucin and with potassium bromide-bromate. These include
methylfurfural (from rhamnosan), hydroxymethylfurfural (from hexo-
sans), and formaldehyde (from lignin). The separation of the
phloroglucin compounds is dependent upon the assumption that
furfural forms with phloroglucin, a product which is insoluble in
alcohol, while the other phloroglucin compounds are soluble. This is
not entirely true. The Kullgren process employs a second distillation,
which destroys 33 percent of the methylfurfural and all of the hydroxy-
methylfurfural. Hughes and Acree [14] studied the reaction of bro-
mine with furfural and methylfurfural at 0°C and found that by
determining the amount of bromine consumed during two periods
of time it was possible to calculate the quantities of furfural and
methylfurfural present. They expressed the consumption of bromine
at two periods of time, based upon the molar consumption of bromine
for each aldehyde, by the following equations:
f=grams of furfural.
m=grams of methylfurfural.
a', and a 2–milliequivalents of bromine consumed by aliquots at
times tº and t2.
a1 and a2–molar consumption of bromine by furfural at ti and tº.
by and b2–molar consumption of bromine by methylfurfural at
tl and t2. *
--- Q1022 - Q2001
7), F (0.055); -;
--- bowl-bia?
f=(0.048); i.
For 5– and 10-minute periods these equations become
(1.00) (22) – (1.00) (c.) .
.00) (1.63)—(1.00) (1.38)
- (1.63) (al) — (1.38) (r.)
f= (0.048) (1.00) (1.63)-(1.00) (1.38)
m = (0.055) (1
2. STANDARD METHOD FOR THE ESTIMATION OF FURFURAL BY
MEANS OF PHLOROGLUCIN
Reagents [6]—Hydrochloric acid.—Contains 12 percent by weight
of hydrogen chloride. To 1 volume of concentrated hydrochloric
244 Circular of the National Bureau of Standards
acid add 2 volumes of water. Determine the percentage of acid
by titration against standard alkali and adjust to proper strength
by dilution or addition of acid, as may be necessary.
Phloroglucin.—Dissolve a small quantity of phloroglucin in a few
drops of acetic anhydride, heat almost to boiling, and add a few
drops of sulfuric acid. A violet color indicates the presence of dire-
Sorcin. A phloroglucin which gives more than a faint coloration may
be purified by the following method. Heat in a beaker about 300
ml of the dilute hydrochloric acid and 11 g of commercial phloroglucin,
added in small quantities at a time, stirring constantly until it is
nearly dissolved. Pour the hot solution into a sufficient quantity
of the same hydrochloric acid (cold) to make the volume 1,500 ml.
Allow to stand at least overnight, preferably several days, to permit
the diresorcin to crystallize. Filter immediately before using. A
yellow tint does not interfere with its usefulness. In using, add the
volume containing the required quantity of phloroglucin to the
distillate.
Determination.—Place such a quantity of the sample, 2 to 5 g, that
the weight of phloroglucide obtained shall not exceed 0.300 g, in a
300-ml distillation flask, together with 100 ml of the dilute hydro-
chloric acid and several pieces of recently ignited pumice stone.
Place the flask on a wire gauze, connect with a condenser, and heat,
rather gently at first, and then regulating so as to distill over 30 ml
in about 10 minutes. Pass the distillate through a small filter paper.
Replace the 30 ml distilled by a like quantity of the dilute acid, added
by means of a separatory funnel in such a manner as to wash down
the particles adhering to the sides of the flask, and continue the pro-
cess until the distillate amounts to 360 ml. To the total distillate
add gradually a quantity of phloroglucin dissolved in the dilute
hydrochloric acid and thoroughly stir the resulting mixture. (The
quantity of phloroglucin used should be about double that of the fur-
fural expected. The solution turns yellow, then green, and very
Soon there appears an amorphous greenish precipitate that grows
darker rapidly, until it becomes almost black.) Make the solution
up to 400 ml with the dilute hydrochloric acid and allow to stand
overnight.
Collect the amorphous black precipitate in a weighed Gooch
crucible having an asbestos mat, wash carefully with 150 ml of water
So that the water is not entirely removed from the crucible until
the very last, and dry for 4 hours at the temperature of boiling water.
Cool, and weigh in a weighing bottle. The increase in weight is taken
to be furfural phloroglucide. To calculate the furfural, pentoses, or
pentosans from the phloroglucide, use the following formulas given
by Kröber:
(1) For a weight of phloroglucide, designated by a in the following
formulas, under 0.03 g: -
Furfural= (a+0.0052) × 0.5170.
Pentoses= (a+0.0052) × 1.0170.
Pentosans= (a+0.0052) × 0.8949.
In the above and also in the following formulas, the factor 0.0052
represents the weight of the phloroglucide that remains dissolved in
the 400 ml of acid solution.
Polarimetry, Saccharimetry, and the Sugars 245
(2) For a weight of phloroglucide a between 0.03 and 0.300 g, use
Kröber's table (table 105, p. 610), or the following formulas:
Furfural= (a+0.0052) × 0.5185.
Pentoses= (a+0.0052) × 1.0075.
Pentosans= (a+0.0052) × 0.8866.
(3) For a weight of phloroglucide a over 0.300 g, use the following
formulas:
Furfural= (a+0.0052) × 0.5180.
Pentoses= (a+0.0052) × 1.0026.
Pentosans= (a+0.0052) × 0.8824.
3. METHOD FOR THE ESTIMATION OF FURFURAL ACCORDING TO
KULLGREN AND TYDEN METHOD
Reagents.-Sodium hydroxide solution, 1.58 N.
A bromate-bromide solution containing 1.392 g of potassium bro-
mate and 10 g of potassium bromide per liter, representing 0.05 N
bromate solution.
Sodium thiosulfate solution, 0.05 N.
Ammonium molybdate solution containing 25 g of the salt per liter.
Hydrochloric acid (density, 1.065) which contains 13.15 percent of
hydrochloric acid.
Sodium chloride and potassium iodide.
(a) PROCEDURE APPLICABLE TO THE DETERMINATION OF PENTOSANS OR
METHYLPENTOSANS
Place a quantity of material corresponding to 0.15 to 0.2 g of xylose
or rhamnose, or 0.20 to 0.30 g of arabinose, in a 300-ml distilling flask
with 100 ml of 13.15-percent hydrochloric acid and 19 to 20 g of
sodium chloride. Continue the distillation for 100 minutes for xylose
and 140 minutes for arabinose and rhamnose at the rate of 25 ml per
10 minutes. After the distillation of each 25 ml add 25 ml of acid.
For xylose 250 ml of distillate is obtained and for arabinose about
350 ml. Make the solution up to 250 ml in the first case, and 400 ml
in the second, with hydrochloric acid. Place a 100-ml portion of this
solution in a 500-ml flask fitted with a cork. While the liquid is cooling,
add 200 ml of 1.58 N sodium hydroxide solution and cool to 18° to
19° C. Add at once 10 ml of ammonium molybdate solution and
25 ml of bromide-bromate solution. Place the flask over a white
surface so as to be able to recognize the appearance of a yellow color.
This usually occurs in zero to 2 minutes' time. Allow the flask to
stand 4 minutes after the appearance of the yellow color, and add 1 g
of solid potassium iodide and shake. Let stand for 5 to 10 minutes
and titrate the liberated iodine with 0.05 N thiosulfate.
The bromate consumed is equal to the volume of solution added
minus the volume of thiosulfate required. The total bromate is ob-
tained by multiplying the volume of bromate consumed by 2.5 for
xylose and by 4 for arabinose and rhamnose. Calling this volume n ml
of 0.05 N. potassium bromate, the quantities obtained in grams are
Furfural= m × 0.00240.
Xylose= n X0.00425. Xylan= n > 0.00374.
Arabinose='m X 0.00506. Araban=m)K0.00445.
Rhamnose (CaFH12O5.H2O) = m × 0.00346.
246 Circular of the National Bureau of Standards
Rhamnosan = m × 0.00278.
Pentosans (general) = m × 0.00410.
To obtain the quantity of furfural in the original substance, increase
the value obtained by 3.1 percent.
(b) ESTIMATION OF PENTOSES OR PENTOSANS IN THE PRESENCE OF HEXOSES
AND POLYOSES
Take a quantity of substance that will give between 0.075 and 0.1 g
of furfural. Carry out the distillation as described above. To the
distillate add 2 ml (or 3 ml if the distillate reaches 350 ml) of hydro-
chloric acid (density, 1.19) and make up to 250 or 400 ml with 13.15-
percent hydrochloric acid. Return 100 ml of this solution to the dis-
tillation flask, add 19 to 20 g of sodium chloride, and repeat the
distillation with the addition of 25 ml of hydrochloric acid after each
25-ml distillation. When 100 ml has come over, neutralize and titrate
as before. Calculate as before. As two distillations have been made,
it is necessary to increase the furfural value by 3.1 percent twice when
determining the amount of furfural produced by the original substance.
GROUND JOINT
e”
FIGURE 41.-Steam-distillation apparatus used for furfural determinations.
1, Distillation flask; 2, thermometer well; 3, titration flask; and 4, Scrubber trap containing water and
Raschrig Pyrex rings.
4. DISTILLATION AND VOLUMETRIC DETERMINATION OF
FURFURAL FROM XYLOSE [5]
The xylose is weighed in a Pyrex micro pan and placed in flask 1
(fig. 41) along with 20 g of sodium chloride. The apparatus is then
completely assembled. One hundred milliliters of 12-percent hydro-
chloric acid is added through the separatory funnel, and the tempera-
ture of the solution in the distilling flask is brought to 103° to 105° C.
Steam at a pressure of 10 pounds per square inch (115° C) is then intro-
duced at such a rate that with the distillation temperature at 110°
+ 19 C, 200 ml of distillate is collected every 30 minutes. A constant
level is maintained in the distillation flask by the addition of hydro-
chloric acid. The acidity of each fraction is determined by removing
1 ml and titrating it with 0.1 N sodium hydroxide (phenolphthalein).


Polarimetry, Saccharimetry, and the Sugars 247
This sample is then returned and the acidity of the distillate adjusted
to about 1 N. The distillation is continued until the final fraction
contains no furfural (aniline acetate test). The receiving flasks, in
whose side arms have been previously placed the 0.1 N potassium
bromate-bromide solution and the potassium iodide solution, are then
placed in an ice bath to attain a temperature of 0° C. The potassium
bromate-bromide solution is run in, thoroughly mixed, and allowed to
react exactly 5 minutes, at which time the potassium iodide is added.
The flask is removed from the ice bath and shaken vigorously to allow
all of the free bromine to react. The contents of the flask are then
titrated with 0.1 N sodium thiosulfate in the presence of starch indica-
tor. Under these conditions 1 mole of bromine reacts with 1 mole of
furfural; hence 1 ml of 0.1 N potassium bromate is equivalent to
0.0048 g of furfural.
A representative analysis is indicated by the following: 0.1600 g of
xylose, 11 fractions of 200 ml, and 21.33 ml total volume of potassium
bromate-bromide solution consumed. The authors were interested
in obtaining 100-percent yields, and thus have used precautions not
required when an error of 1 to 2 percent could be tolerated.
With a 25-mg sample of furfural it was found that 2 percent was
collected in the trap. When rubber stoppers were used to close the
distilling flask, an error of 0.04 to 0.06 ml of 0.1 N potassium bromate-
bromide resulted for each 200 ml of distillate. The potassium bro-
mate-bromide and the potassium iodide solutions may be cooled in
separate containers, the bromate solution being quantitatively washed
into the flask before the thiosulfate titration. The distillate may be
collected in one flask and an aliquot part used for the final titration.
This method has also been applied to rhamnose and arabinose [15].
5. REFERENCES
1] A. Jolles, Sitzber. Akad. Wiss. Wien 114, 1191 (1905); Ber. deut. chem.
Ges. 39, 96 (1906).
| N. C. Pervier and R. A. Gortner, Ind. Eng. Chem. 15, 1167, 1255 (1923).
] G. M. Kline and S. F. Acree, BS J. Research 8, 35 (1932) RP398.
| C. Kullgren and H. Tydén, Ingeniorsvetenskas Akad., Handlingar No. 94
(Stockholm, 1929). Discussed in Methods of Cellulose Chemistry, by
C. Doree (Chapman & Hill, London 1933).
[5] E. E. Hughes and S. F. Acree, J. Research NBS 21, 327 (1938) RP1132.
[6] Official and Tentative Methods of Analysis of the Association of Official
Agricultural Chemists, 5th ed., p. 361 (1940). A. W. Scharger, J. Ind. Eng.
Chem. 15, 748 (1923).
[7] R. Jäger and E. Ungar, Ber. deut. chem. Ges. 36, 1221 (1903).
[8] A. W. Dox and G. P. Plaisance, J. Am. Chem. Soc. 38, 2156 (1916).
W. G. Campbell and L. H. Smith, Biochem. J. 31, 535 (1937).
[10] A. R. Ling and D. R. Nanji, Biochem. J. 15, 466 (1921).
[11] W. J. Powell and H. Whittaker, J. Soc. Chem. Ind. 43, 35 T (1924).
[12] O. C. Magistad, Ind. Eng. Chem., Anal. Ed. 5, 253 (1933).
[13] E. E. Hughes and S. F. Acree, Ind. Eng. Chem., Anal. Ed. 6, 123 (1934).
[14] E. E. Hughes and S. F. Acree, Ind. Eng. Chem., Anal. Ed. 9, 318 (1937).
[15] E. E. Hughes and S. F. Acree, J. Research NBS 23, 293 (1939) RP1233.
ſ
[2
[3
[4
XIII. DENSIMETRY
1. GENERAL
Density is the term used to represent the mass per unit volume
and is expressed in grams per milliliter; thus d- (m/v), in which d
is the density, m the mass, and v the volume of the substance. Since
248 Circular of the National Bureau of Standards
1 ml of distilled water at 4°C, the temperature of its maximum density,
(d=1.00000) weighs 1 g in vacuo, densities are usually referred to
water at 4°C. The standard temperature adopted for sugar analysis
is 20°C, and density measurements are usually made at this tempera-
ture. The density of a sugar solution at 20°C referred to water at
4° C is indicated as follows: dº. Unless otherwise stated, densities
refer to weights reduced to vacuo and are termed “true” or “absolute”
densities.
The term “specific gravity” is used to express the relative masses of
equal volumes of the substance in question and water, each substance
being at a definitely stated temperature. For example, specific gravity
at dº means the specific gravity of the substance at 20°C referred to
water at 20°C as unity. Specific gravity is frequently referred to as
relative density.
2. DEGREES BRIX (OR BALLING)
The system of graduating hydrometers on the basis of the percentage
by weights of sucrose in a pure sucrose solution was first devised by
Balling [1]. The Balling scale was subsequently recalculated by
Brix [2], and the instrument is now generally referred to as the Brix
hydrometer, and the readings are indicated by the term “degrees
Brix.” The original hydrometers were calibrated at 17.5°C, but at
present most Brix hydrometers are standard at 20° C.
3. DEGREES BAUME
The Baumé hydrometer is widely used in the sugar industry, particu-
larly in connection with the sale of molasses and sirups. The original
instrument was devised by Antoine Baumé [3], a French chemist, in
1768. Baumé described his method of graduating the hydrometer in
L'Avant Coureur in 1768 and repeated them in the several editions of
his Elements de Pharmacie. In the eighth edition of this work,
published in Paris in 1797, he stated that he constructed his instru-
ment in this way:
For the hydrometer for liquids heavier than water he prepared a solution of salt
containing 15 parts of salt by weight in 85 parts of water by weight. He described
the salt as “very pure” and “very dry” and stated that the experiments were made
in a cellar in which the temperature was 10° Réaumur (12.5° C). The zero on the
scale indicated the point to which the instrument sunk in distilled water and the
15-mark the point to which it sunk in the 15-percent salt solution.
With a pair of dividers the space between 0 and 15 was divided into 15 equal
parts, and degrees of the same size were continued above 15.
Although the degrees on the Baumé scale are entirely arbitrary and
bear no obvious relation to the density of the liquid, the instrument
met with speedy acceptance by workers in the sugar as well as other
industries. With the general use of the Baumé scale, other investiga-
tors found difficulty in following the original directions for calibrating
the instrument, and the values of the scale divisions have been
variously reported. This led to the introduction of a number of dif-
ferent so-called Baumé scales.
Chandler, [4] in a paper read before the National Academy of Sci-
ences at Philadelphia in 1881, gave an admirable review of the origin
and history of the Baumé scales in use up to that time. He gave
the details of 23 different scales for liquids heavier than water. This
subject of Baumé scales is also discussed in Bureau Circular C59.
Polarimetry, Saccharimetry, and the Sugars 249
In view of the uncertainty which existed because of the number of
different scales, Bates and Bearce [5] devised a new Baumé scale for
sugar solutions. This has three features that commend it for use in
sugar work.
1. It is based upon the density values of Plato, which are considered
the most reliable. .
2. It is standard at 20°C, the most widely accepted temperature
for sugar work.
3. It is based on the modulus 145, which has already been adopted
by the Manufacturing Chemists Association of the United States,
by the National Bureau of Standards, and by all American manufac-
turers of hydrometers.
In constructing this table, Bates and Bearce reduced the Plato
density values dº to specific gravities at 20°/20° C in order that
zero degrees Baumé correspond to zero percentage of sucrose and zero
degrees Brix.
The relation between specific gravity 20°/20° C and degrees Baumé
(Bates and Bearce) is as follows:
t 145 e
sp gr 20°/20° C
The Bates and Bearce table of equivalents is now in general use;
table 109, p. 614.
Degrees Baumé = 145–
4. DETERMINATION OF DENSITY
(a) BY MEANS OF HYDROMETERS
Hydrometers are seldom used for great accuracy, since the usual
conditions under which they are used preclude such special manip-
ulation and exact observation as are necessary to obtain high
precision. It is, nevertheless, important that they be accurately
graduated to avoid, as far as possible, the necessity for instrumental
corrections. To obtain this end, it is necessary to employ certain
precautious and methods in standardizing these instruments.
The hydrometer should be clean, dry, and at the temperature of the
liquid before immersing.
The liquid in which the observation is made should be contained
in a clear, smooth, glass vessel of suitable size and shape.
In order that a hydrometer may correctly indicate the density of a
specified liquid, it is essential that the liquid be uniform throughout
and at the standard temperature.
To insure uniformity in the liquid, stirring is required shortly
before making the observation.
In making the determination, the hydrometer is slowly lowered
into the liquid slightly beyond the point where it floats naturally and
then is allowed to float freely.
The scale reading should not be made until the liquid and hydrom-
eter are free from air bubbles and at rest.
In reading the hydrometer scale, the eye is placed slightly below
the plane of the surface of the test liquid; it is raised slowly until the
surface, seen as an ellipse, becomes a straight line. The point where
this line cuts the hydrometer scale should be taken as the reading of
the hydrometer.
250 Circular of the National Bureau of Standards
The liquid should be at nearly the temperature of the surrounding
air, as otherwise its temperature will change during the observation,
causing not only differences in density but also doubt as to the actual
temperature. When the temperature of observation differs from the
standard temperature of the instrument the observed reading differs
from the normal reading by an amount depending on the difference
in temperature and on the relative thermal expansions of the instru-
ment and the particular liquid. If the latter properties are known,
tables of corrections for temperature may be prepared for use with
hydrometers at various temperatures. Such tables should be used
with caution, and only for approximate results when the temperature
differs much from the standard temperature or from the temperature
of the surrounding air. Such temperature corrections are given in
tables 110 and 111, pp. 624–25. Further information on the use and
testing of hydrometers is given in Bureau Circular C16, The Testing
of Hydrometers.
In case the sample is too dense for direct determination, the follow-
ing dilution method of the AOAC [6] may be employed.
Dilute a weighed portion with a weighed quantity of water or
dissolve a weighed portion and dilute to a known volume with water.
In the first instance, the percentage of total solids is calculated by the
following formula: .
Percentage of solids in the undiluted material= WS/w, in which
S=percentage of solids in the diluted material,
W= weight of the diluted material, and
w-weight of the sample taken for dilution.
When the dilution is made to a definite volume, the following
formula is to be used:
Percentage of solids in the undiluted material=WDS/w, in which
V= volume of the diluted solution,
D=specific gravity of the diluted solution,
S=percentage of solids in the diluted solution, and
w-weight of the sample taken for dilution.
A table for the comparison of density, degrees Brix, and degrees
Baumé, etc., is given in table 109, p. 614.
In applying the dilution method to low-grade products, such as
final molasses, the results obtained are higher than when direct methods
are used. This is due to the fact that when diluted with water the
solutions of the dissolved salts and other impurities contract by
amounts different from solutions of pure sucrose.
(b) BY MEANS OF PICNOMETERS
(1) GENERAL.—For more accurate determinations of the density of
liquid sugar products, such as sirups and molasses, some form of
picnometer or specific gravity bottle is used. The procedure is as
follows: Carefully clean the picnometer by filling with a solution of
potassium dichromate in concentrated sulfuric acid, allowing to stand
for several hours, emptying, thoroughly washing with water, and,
finally rinsing with alcohol. Dry the instrument in an air bath, cool
and weigh. Fill the picnometer with recently boiled distilled water
which has previously been cooled to 18° or 19°C, insert the stopper or
thermometer, being careful to prevent the introduction of air bubbles,
Polarimetry, Saccharimetry, and the Sugars 251
and place the filled instrument in a water thermostat held at 20° C.
Allow to remain in the thermostat for a sufficient time to reach the
temperature of 20° C. Adjust the volume by removing the excess
water which has exuded from the capillary stem, fit the ground-glass
cap in place, and remove the instrument from the bath; wipe dry with
a clean cloth and after allowing to stand for 15 to 20 minutes, weigh.
Reduce the weight in air of the contained water to the weight in
vacuo. Obtain the volume of the picnometer by dividing the weight
in vacuo of the water content by the density of water at 20° C,
0.998.2343. After emptying and drying the picnometer, fill it with the
sample in question, and ascertain the weight of the
contained sample at 20° C. Reduce the weight in
air of the contained sample to the weight in vacuo.
Divide the weight of contained sample in vacuo by
the volume of the picnometer to obtain the true
density, dź.
(2) METHOD OF NEw KIRK.—The accurate de-
termination of the density of blackstrap molasses is
difficult due to the high viscosity of the material
and to the presence of included and dissolved gases.
Newkirk [7] has designed a special picnometer for
making the determination (fig. 42). It consists of a D
bottle, C, fitted with an enlargement at the top, B, U
ground optically flat and closed by another optical
flat, A. An expansion chamber, D, is ground to the
$º
cock, F, so that when the proper vacuum has been
bottle and fitted with a vacuum connection, E. To
reached the apparatus can be closed off from the B
vacuum source. In using the picnometer, the ex-
avoid loss of water due to evaporation under reduced
pressure, the connecting tube is fitted with a stop-
pansion chamber, after lubrication of all joints with
molasses, is placed on the bottle. The molasses to
be analyzed is allowed to flow into the bottle and
into the expansion chamber until the latter is about
one-third full. The vacuum line is then connected
and the pressure reduced until the gas expands into
visible bubbles. The apparatus is then closed off
by turning the stopcock, F, and the whole placed in FIG U R.E. 42–
a thermostat and allowed to remain until the tem- N ºrk p? C-
perature has reached equilibrium and all of the “”
bubbles have collected in the expansion chamber. The expansion
chamber is removed and the volume fixed by carefully sliding plate A
over surface B. The picnometer is then removed from the thermo-
stat, wiped clean, placed in the balance case, and weighed. The
weight of the contained sample is corrected to vacuo and compared
with the weight of an equal volume of water at 4°C in vacuo.
(3) WEIGHT PER GALLON of MoDAssEs.—Since, in commercial
transactions, molasses is sold both by volume and by weight, the
determination of the weight per gallon is of considerable importance.
The method employed at the National Bureau of Standards and
adopted by the United States Customs Service is as follows:
C


252 Circular of the National Bureau of Standards
A special 100-ml calibrated volumetric flask with a neck of approxi-
mately 8 mm inside diameter shall be used. Weigh the flask empty
and then fill it with molasses, using a long-stem funnel reaching below
the graduation mark, until the level of the molasses reaches the lower
end of the neck of the flask. The flow of molasses may be stopped
by inserting a glass rod of suitable size into the funnel so as to close
the stem opening. Remove the funnel carefully to prevent the molas-
ses coming in contact with the neck, and weigh flask and molasses.
Add water almost up to the graduation mark, running it down the
side of the neck to prevent mixing with the molasses. Allow to stand
several hours or overnight to permit the escape of bubbles. Place
the flask in a constant temperature water bath at 20°C for a sufficient
time for it to reach the temperature of the bath, then make to volume
at that temperature, with water. Weigh. Reduce the weight of
the molasses to vacuo and calculate the density.
Eacample.
Weight per gallon determined at 20° C.
Weight of flask, 37.907 g.
Weight of flask and molasses, 167.148 g.
Weight of flask, molasses, and water, 174.711 g.
167.148 g–37.907 g = 129.241 g = weight of molasses (in air with brass weights).
174.71.1 g – 167.148 g- 7.563 g = weight of water (in air with brass weights).
Calculating volume of water from weights in air at 20° C.
Divide weight of water in air by weight of 1 ml of water in air at 20° C (table
106, p. 612), 7.563/0.99718 = 7.584 ml.
Volume of flask at 20° C, 100. 060 ml
7. 584 ml
*
92. 476 ml= volume of molasses.
To reduce weight of molasses to vacuo:
129.241/8. 4 = 15.4 ml= volume of brass weights.
(8.4 = density of brass weights).
92.5 ml= volume of molasses (approximate).
15.4 ml = volume of weights.
77.1 ml= net volume of air displaced.
77.1 × 0.0012=0.093 g, buoyancy correction to be added to weight of molasses.
(0.001.2 g = weight of 1 ml of air at 760 mm at 20° C).
129. 241
0.093
129. 334 = weight of molasses in a vacuum.
. 129.334
% = — = 1.3986.
92.476
By interpolation from table 117, p. 644,
Weight per gallon in air at 20° C = 11.664 pounds.
(c) BY MEANS OF DIRECT-READING BALANCE
The weight per gallon of molasses may be determined directly by
means of a torsion balance designed by H. J. Bastone, of the American
Sugar Refining Co. It is fitted with two beams, one a double beam
for taring the sample bottle, and the other a recording beam gradu-
ated in pounds per gallon from 10.80 to 12.05 in 1/100 pound per
Polarimetry, Saccharimetry, and the Sugars 253
gallon. A bottle or picnometer for containing the molasses is fur-
nished with the balance. The performance of the balance has been
investigated by Snyder and Hammond [8], who deemed it more
convenient and accurate to fix the volume by sliding a flat glass disk
seated on the flat polished top of the perforated stopper. Johnson
and Adams [9] and Newkirk [7] have shown the accuracy of thus
fixing the volume. By this procedure only a very thin film of mo–
lasses remained between the disk and the top of the stopper. The
calibration of the volume of the bottle and the direct determinations
were made in the same manner.
This balance seems entirely satisfactory for most determinations
of the weight per gallon of molasses, provided the usual precautions
are taken to allow the foam to subside and occluded gases to escape.
Any direct-reading balance will be found useful in commercial work
and routine testing as compared with other methods, since results
may be obtained without resort to tedious calculations.
(d) BY MEANS OF ANALYTICAL BALANCE
Another method of determining the specific gravity of sugar solu-
tions is based on the well-known principle of Archimedes that a body
immersed in a liquid is buoyed up by a force equal to the weight of
the displaced liquid. In making a determination, a glass sinker or
bulb weighted with mercury is suspended from the arm of a balance
by means of a fine platinum wire. It is weighed in air, immersed in
distilled water, and immersed in the sugar solution. The specific
gravity is calculated from the equation
A–C
S A—B'
where
S=specific gravity of sugar solution,
A=weight of sinker in air,
B=weight of sinker in distilled water,
C=weight of sinker in sugar solution.
By reducing the weights in air to weights in vacuum and taking
into account the temperature, the density of the air, and the atmos-
pheric pressure, the true density may be calculated.
The so-called Westphal balance employs the same principle as
the above and is so graduated that the specific gravity is obtained
directly from the readings of the riders on the beam. A more de-
tailed discussion may be found in textbooks on physics.
5. DENSITY OF SUCROSE SOLUTIONS
The density of sucrose solutions of different concentrations has been
the subject of extensive study by investigators over a period of many
years. Among the early workers in the field were Balling [1], Niemann
[10], Brix [2], Gerlach [11], Scheibler [12], and others. A number of
tables were published, varying with respect to the temperature, and
expressed in terms of true density or of specific gravity. In 1900 the
German Normal-Aichungs-Kommission published density tables of
sucrose solutions [13] based on the very precise determinations of
323414°–42—18
254 Circular of the National Bureau of Standards
F. Plato in collaboration with J. Domke and H. Harting. These
tables include the percentages of sucrose by weight for density at
20°/4° C, table 113, p. 626, and specific gravities 15° C/15° C and
tº C/15° C. These tables are considered the most accurate available
and are universally accepted as standards. Using the Plato tables
as a basis, numerous other tables have been computed, giving such
values as grams of sucrose per 100 g of solution (Brix), grams of
sucrose per 100 ml of solution, etc. Among the more widely used of
these are the tables of Sidersky, Les densités des solutions sucrees à
differentes temperatures, Paris, 1908.
6. REFERENCES
[1] C. J. N. Balling, Gahrungschemie 1, pt. 1, p. 119.
[2] A. Brix, Z. Ver. deut. Zucker-Ind. 4, 304 (1854).
[3] A. Baumé, Elements de Pharmacie (Paris, 1797).
[4] C. F. Chandler, Mem. Am. Nat. Acad. Sci. 3, I, 63–73 (1884).
[5] F. J. Bates and H. W. Bearce, Tech. Pap. BS (1918) T115.
[6] Official and Tentative Methods of Analysis of the Association of Official
Agricultural Chemists, 5th ed., p. 485 (1940).
[7] W. B. Newkirk, Tech. Pap. BS 13 (1920) T161.
[8] C. F. Snyder and L. D. Hammond, Tech. Pap. BS 21 (1927) T345.
[9] J. Johnson and L. H. Adams, J. Am. Chem. Soc. 34, 566 (1912).
[10] C. von Niemann, Erdmann's J. Ötonomische tech. Chem. 15, 106.
[11] th Gerlach, Dingler's Polytech. J. 172, 31; Z. Ver. deut. Zucker-Ind. 13, 283
1863). -
[12] C. Scheibler, Neue Z. 25, 37, 185 (1890).
[13] F. § J. Domke, and H. Harting, Z. Ver. deut. Zucker-Ind. 50, 982, 1079
1900).
XIV. REFRACTOMETRY
1. GENERAL
The refractive index of a pure sucrose solution is an accurate measure
of the concentration of dissolved substance. The first refractometer
table appears to have been prepared by Ströhmer [1], who showed the
relation between the refractive index and the specific gravity of sugar
solutions. Stolle [2] determined the refractive indices of solutions
of sucrose, dextrose, levulose, and lactose, using the Pulfrich refrac-
tometer. He found but little variation in the refractive index of
solutions of the different sugars at the same concentration.
Tolman and Smith [3], using an Abbe refractometer, found that
solutions of a number of sugars and related substances in equal
percentage composition by weight gave approximately the same refrac-
tive index. They recommended the use of the refractometer in the
determination of soluble carbohydrates in solution and pointed out
the advantages of the method from the standpoint of speed, ease of
manipulation, and the small amount of sample required.
To expand the usefulness of the refractometer, Geerligs [4] showed
that the refractive indices of impure sugar solutions, even when the
impurities consisted of mineral salts, yielded far more reliable measures
of total dissolved substance than the determinations by densinetric
measurement.
Hugh Main [5] prepared a table of refractive indices of sucrose
solutions and demonstrated the applicability of the Abbe refrac-
tometer in sugarhouse work. Schönrock [6], using methods of high
precision, determined the indices of sucrose solutions for concentra-
Polarimetry, Saccharimetry, and the Sugars 255
tions ranging from 0 to 66 percent. Landt [7] redetermined the
indices for concentrations from 0 to 24 percent and obtained values
in almost perfect agreement with the Schönrock values for that range.
In 1936 the International Commission for Uniform Methods of
Sugar Analysis, realizing the need for a standard table of refractive
indices of sugar solutions, adopted such a table [8]. This table,
known as the “International Scale (1936) of Refractive Indices of
Sucrose Solutions at 20°C,” is constructed from the values of Schön-
rock-Landt (1933) up to 24 percent, of Schönrock (1911) from 24
to 66 percent, and of Main from 71 to 85 percent. The values 67
to 71 were obtained by extrapolation of the Schönrock values as a
straight-line curve to meet the Main value at 71. This table in an
expanded form is given in table 122, p. 652. -
A similar table, based on the same data for use with the tropical
model refractometer, standard at 28°C, is given in table 124, p. 658.
Temperature corrections are made by means of tables 123 and 125.
2. PRINCIPLES OF THE ABBE REFRACTOMETER
When a ray of light travels through a homogeneous medium, its
path is a straight line. However, when the ray passes from one
medium to another at an angle
oblique to the surface of separa-
tion of the two media, the
direction of the ray changes N
abruptly at the surface of sepa- K |
ration. In addition to the por- M
tion of the ray which penetrates OL
the second medium and is bent
or refracted, a portion of the //K% roz 25%
light is reflected. According to .
Snell's Law, the sine of the e
angle of refraction bears a con-
stant ratio to the sine of the R |N'
angle of incidence for all angles -
of incidence, the value of the
ratio depending on the nature
of the two media at the surface
of separation at which the refraction takes place, and also on the
wave length of the incident light. This law is usually expressed as
FIGURE 43.−Refraction of light.
=#, (59)
where n is the index of refraction; i, the angle of incidence; and r,
the angle of refraction. This is illustrated by figure 43.
Suppose AB represents the surface of separation between two
media, say, air above and water below, and that a ray of light having
the direction IO is incident to AB at O. Let NON’ be the normal to
the surface of separation, AB. A portion of the light of the ray
IO is reflected in the direction OK; the other portion is refracted in
the direction OR. The angle IOM, or o, is the angle of incidence, and
angle ROm, or 3, is the angle of refraction.


256 Circular of the National Bureau of Standards
In sugar analysis two types of refractometers are generally used,
the Abbe and the immersion. In both of these the method of grazing
incidence is employed. If light passes from a rarer to a denser
medium, the angle of refraction will be smaller than the angle of
incidence. The largest angle of incidence is 90°, and therefore there
will be a maximum angle of refraction (less than 90°). This angle is
called the critical angle. Equation 59 then becomes
|
- ? (60)
SLI) 7°C
7) =
where re is the critical angle.
In the Abbe refractometer, instead of actually reading the value of
the critical angle in degrees and minutes and computing the index by
means of a formula, the sector scale of the instrument is graduated
directly in refractive indices, the intervals of which have been com-
puted for the constants of the glass of the Abbe prisms. In making a
determination with the instrument, the high-index prism is rotated
about an axis perpendicular to the axis of the observing telescope until
the border line of total reflection coincides with the intersection of the
cross hairs of the telescope. Attached to the prism is an alidade with
index, which moves along the graduated sector scale as the prism
is rotated, permitting the reading of the index.
In the immersion refractometer the objective lens of the telescope
forms an image of the border line between the light and dark portions
of the field on a scale engraved on the plane side of the collecting lens
in the eyepiece.
In both the Abbe and the immersion refractometer, compensators
are provided to permit the use of white-light illumination. In the
Abbe instrument two Amici prisms, which rotate in opposite directions,
compensate for the combined dispersion of the sample and prism and
produce a sharp image of the dividing line. These compensating
prisms furnish a means of measuring the dispersion.
(a) DISPERSION
The dispersion of a substance, (no–1/nº-no) may be calculated
from the amount of rotation of the compensator prisms with respect
to one another. no, nr., and no are the indices of the substance for
the sodium line, the blue hydrogen line, and the red hydrogen line,
respectively. By means of a drum on which is engraved an arbitrary
scale, one of the Amici compensating prisms is rotated until the border
line is achromatized and the scale reading taken. Suitable charts or
tables are furnished by the manufacturers to facilitate conversion of
the scale readings to values for the dispersion.
(b) EFFECT OF TEMPERATURE
Both the refractive index and the dispersion vary with change of
temperature. For liquids the temperature coefficients generally are
larger and negative. It is therefore essential that the temperature
be known and be kept constant during observation. Most Abbe
refractometers are provided with water-jacketed prisms, which permit
the circulation of water at a constant temperature. These instru-
ments are also fitted with suitable thermometers for indicating the
temperature of the material and the prisms.
Polarimetry, Saccharimetry, and the Sugars 257
(c) ILLUMINATION
The refractometer may be illuminated by daylight. It has been
found more satisfactory, however, to use an incandescent electric
lamp of suitable intensity, provided with a shield to eliminate the
disturbing influence of extraneous light.
(d) ADJUSTMENT OF THE INSTRUMENT
In many laboratories, the scale of the Abbe refractometer is fre-
quently checked for adjustment, a practice which should be generally
Figure 44.—Abbe refractometer.
followed. Most instruments are furnished with a test plate made of
special glass and whose index has been carefully measured and the
value engraved on it. The test plate is applied to the upper prism
with the polished end toward the light source, by means of a drop of
monobromnapthalene. A series of careful readings is then taken, and
the average value thus obtained is compared with the value engraved
on the test plate. If necessary, the correction may be made by turn-
ing a small screw in the telescope tube, which moves the objective,
causing the dividing line to shift. -

258 Circular of the National Bureau of Standards
(e) METHOD OF DETERMINING REFRACTIVE INDEX
Place a few drops of the solution on the polished face of the fixed
prism and slowly bring the two prisms together and clamp them.
To insure a sharp, clear image use sufficient liquid to fill the space
between the prisms. Swing the instrument to an upright position and
adjust the illuminating mirror so that the light source is reflected into
the lower prism of the instrument. Rotate the compensating prisms
to obtain a sharp colorless dividing line. Circulate water at a con-
stant temperature, preferably 20° C, through the jackets of the
prisms long enough to allow the temperature of the prisms and of the
sample to reach an equilibrium, continuing the circulation during
observations and taking care that constant temperature is maintained.
If the determination is made at a temperature other than 20° C,
correct the reading to the standard temperature of 20°C by means of
tables 123 or 127, pp. 657, 664.
Caution must be observed if the humidity causes condensation of
moisture on the exposed faces of the prisms. If such a condition
exists, make the measurements at room temperature and correct the
readings to 20°C by means of table 123 or 126.
Dark-colored solutions, such as molasses, are frequently difficult
or even impossible to read on the refractometer. In such cases it is
necessary to follow the procedure of Tischtschenko [9], who diluted
the dark-colored solution with a pure sucrose solution of about the
same concentration. Water should never be used, since such dilu-
tion introduces errors due to contraction in volume. The method
employed is as follows:
Mix thoroughly a weighed quantity of the solution under exami-
nation (A) and a weighed quantity of a solution of pure sucrose of
about the same concentration (B) whose sugar content has been
previously determined by the refractometer. Obtain the refractive
index of this mixture and, by means of table 122, p. 652, convert to
percentage of dry substance. The percentage of dry substance in
the sample in question is calculated by the formula:
(A+B) C–BD
X= A y
(61)
where
X=percentage of dry substance to be found,
A=weight in grams of the sample mixed with B,
B= weight in grams of pure sucrose solution used in the dilu-
tion,
C= percentage of dry substance in the mixture A+B obtained
from the refractive index,
D= Percentage of dry substance in the pure sucrose solution
obtained from its refractive index.
In using the refractometer for determining the percentage of dry
substance in solution, it is well to consider the effect of impurities,
such as salts and organic nonsugars. Tolman and Smith [3] and
others have shown that the instrument is applicable for determining
the soluble carbohydrates in solution. The various sugars have ap-
proximately the same refractive index for equal concentrations.
Stanek [10] has shown the effect of organic salts of sodium and po-
tassium on the refractometric estimation of dissolved solids.
Polarimetry, Sacchari metry, and the Sugars 259
3. IMMERSION REFRACTOMETER
This instrument is designed for the measurement of solutions in
bulk, but, with accessory prisms, may be used where only small
quantities of solution are available.
Originally the immersion instrument of Zeiss [11] was designed
with a single prism having a range of refractive indices from 1.32 to
1.36. The present design permits the use of interchangeable prisms,
usually six in number, extending the range to 1.54. The arbitrary
scale of the instrument, graduated in equal divisions from –5 to
+105, is engraved on the plane side of the collecting lens of the
& y &
Figure 45.-Immersion refractometer.
eyepiece. The image of the border line is coincident with the scale.
By means of the micrometer drum, readings may be made to tenths of
a scale division. Each instrument is furnished with tables for con-
verting the readings on the arbitrary scale to refractive indices.
Since the relation between the arbitrary scales and refractive indices
is not the same for all immersion refractometers, it is necessary to
make the conversons by means of the tables furnished with the
individual instrument.
The refractive indices corresponding to the scale divisions of the
original single prism Zeiss immersion refractometer are given in table

260 Circular of the National Bureau of Standards
TABLE 32.-Refractive indices corresponding to the scale divisions of the original
Zeiss immersion refractometer
Scale Refractive Scale Refractive
reading index reading index
—5 1. 32539 55 1. 34836
0 1. 32736 60 1. 35021
+5 1. 32932 65 1. 35205
10 1. 33126 70 1. 35.388
15 1. 33320 75 1. 35569
20 l. 33513 80 1. 35750
25 1. 33705 85 1. 35930
30 1. 33896 90 1. 36109
35 1. 34086 95 }. 36287
40 1. 34275 100 1. 36464
45 1. 34463 105 I. 36640
50 1. 34.650
In the Bausch & Lomb immersion refractometer the six inter-
changeable prisms were furnished and have the following index ranges:
A, 1.32539 to 1.36639.
B, 1.36428 to 1.40608.
C, 1.39860 to 1.43830.
D, 1.43620 to 1.47562.
E, 1.47320 to 1.51335.
F, 1.50969 to 1.54409.
The adjustment of the scale of the instrument is made for each
prism by means of a test solution or test plate.
With prism A the adjustment is made with distilled water; B, with
a standard sodium chloride solution; C, with a test piece of fluorite;
and D, E, and F, with glass test pieces.
The observations regarding illumination and temperature control
of the Abbe refractometer also apply to the immersion instrument.
The use of the immersion refractometer has been found advantageous
by Bachler,[12], who devised a “one-solution method of analysis of sugar
products,” in which a sufficient quantity of a normal weight solution
of the product is prepared and all or part of the necessary analytical
data are obtained on this one solution. Certain changes were neces-
sary in the immersion refractometer. At the suggestion of Bachler,
the firm of Carl Zeiss, of Jena, produced an immersion refractometer
with a single prism having a range of from mp 1.331 to 1.372 and
adjusted with distilled water at scale division 0. With the use of
this instrument and the Goldbach flow-through cell, the method has
been shown to give satisfactory results for factory control work.
4. SPECIAL REFRACTOMETERS
For special purposes there are available other types of refrac-
tometers. A pocket-type instrument is used for the estimation of the
Sugar present in the juice of the cane. Another special type is the
factory refractometer, which is mounted on the vacuum pan and
permits readings to be taken during the boiling process.
A new type of laboratory instrument is now in the course of manufac-
ture by the Bausch & Lomb Optical Co. It is mounted in a hori-
Zontal position and illuminated by a sodium lamp. It combines
features of both the Abbe and the immersion instruments and is
capable of readings to a few units in the fifth decimal place.
Polarimetry, Saccharimetry, and the Sugars 261
5. REFERENCES
[1] F. Strohmer, Oesterr-ungar. Z. Zuckerind. I andw. 12, 925 (1883); 13, 185
(1884).
[2] F. Stolle, Z. Ver. deut. Zucker-Ind. 51, 469 (1901).
[3] L. M. Tolman and W. B. Smith, J. Am. Chem. Soc. 28, 1476 (1906).
[4] H. C. P. Geerligs, Arch. Suikerind. 15, 487 (1907).
5] H. Main, Int. Sugar J. 9, 481 (1907).
[6] O. Schönrock, Z. Ver. deut. Zucker-Ind. 61, 424 (1911).
[7] E. Landt, Z. Ver. deut. Zucker-Ind. 83, 692 (1933).
[8] E. Landt, Int. Sugar J. 39, 225 (1937).
[9] J. Tischtschenko, Z. Ver. deut. Zucker-Ind. 59, 103 (1909).
[10] W. Stanek, Z. Zucker Ind. Böhmen 34, 5 (1909).
[11] C. Pulfrich, Z. angew. Chem. p. 1168 (1899).
[12] F. R. Bachler, Facts About Sugar 28, 420 (1933).
XV. DETERMINATION OF MOISTURE
1. GENERAL
An accurate determination of the moisture in sugar products is fre-
quently a matter of great difficulty, and the proper procedure has not
been definitely established. Moist sugar or sugar products, sirups, and
molasses resist drying with great obstinacy. Sometimes the material
is hygroscopic. At ordinary pressures, moisture can be removed only
by prolonged heating at a high temperature. But a high temperature
frequently exerts a destructive effect on the solid sugars. The destruc-
tive action of a temperature of 100° C. is a particularly important
consideration in the case of levulose and, to a less extent, in the cases
of dextrose and sucrose. Consequently, the best drying methods are
those which combine mild temperature and high vacuum. If the
substance is in the form of a sirup, drying is facilitated by mixing it
thoroughly with dry quartz sand or pumice. The action of the sand
is to cause a larger area to be exposed and prevent the formation of a
crust. Flaked asbestos or, for fluid substances, a roll of filter paper
may be used.
Below are given various methods in common use for determining dry
substance. The method to be adopted depends somewhat upon the
material. If levulose is present in considerable quantity, the tem-
perature of drying should not exceed 70° C. .
2. METHOD OF THE UNITED STATES BUREAU OF CUSTOMS
For control analysis of raw sugars, the Bureau of Customs, Treasury
Department, has adopted an arbitrary method which yields readily
reproducible results. The procedure is as follows [1]: For the determi-
nation of moisture in sugars, dry approximately 4 g in a metal dish
55 mm in diameter and 15 mm in height. Subject each sample to a
temperature of 100° C. for 2 hours, care being exercised that the dishes
are not in close proximity to the heaters.
In making the determination, dishes of polished aluminum with
tightly fitting covers are used. Upon removing from the drying
oven, the dish is immediately covered and placed in a desiccator. As
soon as the dishes and contents have cooled, they are weighed. The
loss of weight is expressed as moisture.
262 Circular of the National Bureau of Standards
3. METHODS OF THE ASSOCIATION OF OFFICIAL AGRICULTURAL
CHEMISTS
(a) DIRECT DRYING [2]
(Applicable to Cane and Beet Raw and Refined Sugar)
Dry 2 to 5 g of the prepared sample in a flat dish (Ni, Pt, or Al), at
the temperature of boiling water, for 10 hours; cool in a desiccator and
weigh. Dry again for an hour or until the change in weight is not
more than 2 mg. For sugars of large grain, heat at 105° to 110°C
to expel the last traces of occluded water. Report the loss as moisture.
(b) VACUUM DRYING [3]
Dry 2 to 5 g of the prepared sample in a flat dish (Ni, Pt, or Al,
and with a tightly fitting cover) at a temperature not exceeding 70°C
(preferably at 60° C), under a pressure not exceeding 50 mm of Hg,
and for 2 hours. Remove from the oven, put cover in place, cool in
desiccator, and weigh. Redry for an hour and repeat until the change
in weight is not more than 2 mg between successive weighings at 1-hour
intervals. The oven should be bled with a current of dry air during
drying to insure removal of water vapors.
(c) DRYING ON QUARTZ SAND [2]
(Applicable to massecuites, molasses, and other liquid and semiliquid products)
Digest pure quartz sand that will pass a 40-mesh but not a 60-mesh
sieve with hydrochloric acid, wash free from acid, dry, and ignite.
Preserve in a stoppered bottle. Place 25 to 30 g of the prepared sand
and a short stirring rod in a dish approximately 55 mm in diameter and
40 mm in depth, fitted with a cover. Dry thoroughly, cover dish,
cool in a desiccator, and weigh immediately. Then add sufficient
diluted sample of known weight to yield approximately 1 g of dry
matter and mix thoroughly with the sand. Heat on a steam bath for
15 to 20 minutes and stir at intervals of 2 to 3 minutes, or until the
mass becomes too stiff to manipulate readily. Dry at 70° C under a
pressure of not to exceed 50 mm of mercury. Make trial weighings
at 2-hour intervals toward the end of the drying period (about 18
hours) until the change in weight does not exceed 2 mg.
For materials containing no levulose or other readily decomposable
substance, the material may be dried at atmospheric pressure by heat-
ing 8 to 10 hours in a water oven at the temperature of boiling water.
The sample is cooled in a desiccator and weighed; the heating and
weighing are repeated until the loss in 1 hour does not exceed 2 mg.
The loss of weight is reported as moisture.
(Dry sand, as well as the dried sample, will absorb an appreciable
quantity of moisture after standing over most desiccating agents,
therefore all weighings should be made as quickly as possible after
cooling in the desiccator.)
4. ADDITIONAL METHODS
The length of time required to determine moisture in molasses and
other low-grade products by drying on sand has led to the introduc-
tion of a number of special methods, such as the method of Spencer
Polarimetry, Saccharimetry, and the Sugars 263
[4] and the method of Rice and Boleracki [5]. In the Spencer method
the drying is effected in a specially designed electric oven. The
method is applicable to solid sugars as well as liquid sugar products.
The samples are placed in aluminum capsules fitted with metallic
gauze bottoms which permit free passage of air. When liquid or
semiliquid products are to be dried, the sample is absorbed on asbestos
[6]. Air, heated by passing over an electric heating element, is passed
through the sample and the moist air is continuously withdrawn by
suction.
The Rice and Boleracki method [5] consists in spreading a very
thin film of molasses or sirup on thin sheets of silver and drying in a
vacuum oven at 70° C. In the hands of an experienced operator
the method appears to yield concordant results and has the added
advantage of rapidity. It is necessary to exercise some care in pre-
paring the film for drying and also in the manipulation during drying
and weighing. The authors recommend the method for the determi-
nation of moisture in such products as honey, invert sirup, and black-
strap molasses.
5. REFERENCES
U. S. Customs Regulations (see p. 797 of this Circular).
1]
2] Official and Tentative Methods of Analysis of the Association of Official
Agricultural Chemists, 5th ed. p. 484, 485 (1940).
3] J. Assn. Official Agri. Chem. 21, 89 (1938).
4] G. L. Spencer, J. Ind. Eng. Chem. 13, 70 (1921).
3. § W. Rice and P. Boleracki, Ind. Eng. Chem., Anal. Ed. 5, 11 (1933).
6] G.
[
[
[
|
[ P. Meade, J. Ind. Eng. Chem. 13, 924 (1921).
XVI. DETERMINATION OF ASH
Although the determination of ash in sugars and sugar products is
subject to considerable uncertainty, it is still widely used as an indi-
cation of the mineral constituents present. In routine analysis the
Socalled “sulfated-ash” method is employed, largely on account of
its simplicity and reproducibility. In this method any volatile con-
stituents, such as Cl, NO3, CO2, etc., are driven off and are replaced
by SO4. This replacement is considered advantageous in that it com-
pensates for the losses. A further advantage is the conversion of
volatile salts, such as KCl, into the nonvolatile sulfate. The method
is as follows:
1. SULFATE METHOD
Weigh 2 to 5 g of the sample in a 50- to 100-ml platinum dish, add
0.5 ml of concentrated H2SO4 or 1.0 ml of 1:1 H2SO4, heat gently on a
hot plate until the sample is well carbonized, and then heat in a muffle
furnace at a low red heat until all carbon is burned. Cool and add a
few drops more of H2SO4, heat until this is fully volatilized, then cool
in desicator and weigh. Reignite in the muffle furnace to constant
weight. Express the result as the percentage of sulfated ash.
The general practice in many laboratories is to deduct one-tenth of
the amount of sulfate ash to reduce to the normal ash. This deduc-
tion of 10 percent has been studied by many investigators and found
to be in error for cane products. Jamison and Withrow [1] found that
the value for sulfate ash in Cuban raw sugar, even with the customary
10-percent correction, was about 34 percent higher than the ash by
264 Circular of the National Bureau of Standards
direct incineration. Ogilvie and Lindfield [2] found the correction
factor to be from 12 to 15 percent for beet sugars and from 6 to 26
percent for cane sugars.
Jamison and Withrow proposed a modification of the sulfate method,
in which they added 2 ml of sulfuric acid (2:1) to the sample of sugar,
heated the sample on a hot plate until completely carbonized, and
finally ignited it in the muffle furnace to a white ash. After cooling
the ash, they added 3 or 4 drops of sulfuric acid (2:1) and heated it
until the excess acid was driven off. They again ignited the ash in
the muffle for 15 minutes.
2. METHODS OF THE ASSOCIATION OF OFFICIAL AGRICULTURAL
CHEMISTS [3]
In addition to the sulfate-ash method, the AOAC has adopted as
official two methods for carbonated ash, as follows: -
Method I.-Heat 5 to 10 g of the sample in a 50- to 100-ml platinum
dish at 100° C until the H2O is expelled, add a few drops of pure olive
oil, and heat slowly over a flame until swelling ceases. Then place
the dish in a muffle and heat at low redness until a white ash is ob-
tained. Treat the residue with a little (NH4)2CO3 solution, reevapo-
rate, and heat again in the muffle at a very dull red heat to constant
weight.*
Method II.--Carbonize 5 to 10 g of the sample in a 50- to 100-ml
platinum dish at a low heat and treat the charred mass with hot
water to dissolve the soluble salts. (In low-purity products the addi-
tion of a few drops of pure olive oil may be desirable.) Filter through
an ashless filter, ignite filter and residue to a white ash, add the filtrate
of soluble salts, evaporate to dryness and ignite to about 525° C to
constant weight.*
3. ADDITIONAL METHODS
A number of other methods of determining ash have been proposed
by various investigators, the details of some of which have been col-
lected by Jamison and Withrow [1]. The methods are as follows:
Oxalic acid method of Grobert [4].
Quartz sand modification of Alberti and Hempel [5].
Benzoic acid modification of Boyer [6].
Zinc oxide modification [7].
Lixiviation modification [8].
Von Lippman advocates taking the dried-out sample on which the
water determination has been made, saturating it with Vaseline oil
(having a boiling point of about 400° C), and igniting the mixture.
The carbonized mass is then to be burned to ash in a mixed current
of air and oxygen.
Since certain insoluble materials, such as sand and clay, which may
be present in the sugar, and would therefore be included in the ash
as determined by incineration, have no appreciable effect on the sugar
in the process of refining, it is frequently necessary to determine the
percentage of soluble ash. This may be accomplished by dissolving
the sugar in hot water, filtering, washing the filter thoroughly with
hot water, and evaporating the combined filtrate and washings in a
platinum dish to dryness. The ash in the dry residue is then deter-
mined by one of the standard methods.
*The use of (NH4)2CO3 was dropped in 1940.
Polarimetry, Saccharimetry, and the Sugars 265
The determination of ash by means of conductivity measurements
is treated in chapter XVII, p. 275.
4. REFERENCES
[1] U. S. Jamison and J. R. Withrow, J. Ind. Eng. Chem. 15, 386 (1923).
[2] J. P. Ogilive and J. H. Lindfield, Int. Sugar J. 20, 114 (1919).
[3] Official and Tentative Methods of Analysis of the Association of Official
Agricultural Chemists, 5th Ed., p. 487 (1940).
[4] J. de Grobert, J. Chem. Soc. 58, 670 (1890).
[5] Alberti and Hempel, Deut. Zuckerind. 16, 1069 (1891).
[6] E. Boyer, J. Chem. Soc. 58, 1472 (1890).
[7] A. H. Allen, Commercial Organic Analysis, 4th ed., p. 346 (P. Blakiston's
Sons & Co., New York, N. Y., 1909.)
[8] Methods of Sugar Analysis, p. 10 (The Great Western Sugar Co., Denver,
Colo., 1920).
XVII. ELECTRICAL CONDUCTANCE OF SUGAR
SOLUTIONS
1. INTRODUCTION
Since the electrical conductance of a liquid may be made a measure
of the concentration and mobility of conducting particles in solution,
its measurement is useful in determining these qualities in sugar
products. It has been used extensively, principally as a rapid method
of estimating the ash content of solutions [1, 2, 3] at various stages
of manufacture in order to predict their performance in subsequent
stages or as an index of the quality of the finished product. Many
have found, however, that it is not always necessary to convert the
conductance measurement to the more familiar value of sulfate or
carbonate ash. In such cases, conductance values are reported in
units of specific conductance.
More recently, conductance measurements have come into use in
the sugar-manufacturing process to control such operations as boiling
[4], crystallization [5], centrifuging [6], and others [7], and in the
laboratory to determine purity (8, 9) and concentration of solute
[10].
Briefly, electrical conductance is the reciprocal of electrical re-
sistance. In sugar solutions it is expressed in units of specific con-
ductance or reciprocals of units of specific resistance, which in turn
may be defined as the resistance in ohms of a column of liquid 1 cm
long and having a uniform cross-sectional area of 1 cm *.
To determine the specific conductance of any volume of liquid
containing an electrolyte, it is therefore necessary to measure (a)
the resistance in ohms of the liquid, and (b) the dimensions of the
volume of liquid causing this resistance. This measurement may be
performed with great precision, provided errors depending on the
temperature of the solution, the construction of the bridge, oscillator,
balancing capacitor, resistance standards, and change of apparent
resistance with frequency, have been eliminated or corrected [11, 12].
The resistance of the solution is determined by connecting the cell,
Zz, figure 46, in one arm of an alternating-current bridge and adjusting
R, and C, until no current flows between the points C and D, as de-
tected by means of head phones, T. Then, if Zi and Z, are elec-
trically the same, the value of R, may be used to determine the
resistance of the column of solution in the cell.
266 Circular of the National Bureau of Standards
The volume of liquid causing this resistance is most conveniently
measured indirectly as explained later under the section on Con-
ductivity Cells, p. 268.
The possibility of electrolysis and oxidation-reduction in sugar
solution has dictated the use of alternating current for the measure-
ment of electrical conductance. Although alternating current does
tend to reverse the effects of electrolysis, this reversal is not complete
except under special conditions. Furthermore, the use of alternating
current has introduced complicated electrical phenomena in the bridge
network. The conductivity cell, being a part of this network, be-
haves in a manner that can be approximately simulated by a circuit
made up of resistors and capacitors [12, 44]. The resistance of the
column of liquid in the cell can be balanced by the variable resistor,
/NJ
FIGURE 46.-Direct-reading bridge circuit for electrical conductance.
R, figure 46, and the capacitance is most conveniently balanced by
the variable capacitor, C, placed in parallel with the variable resistor.
There still remains, however, a residual effect, which will be referred
to as electrode-polarization reactance. The magnitude of this effect,
which tends to increase the apparent resistance of the solution, is
influenced by the degree of platinization, the material of the electrodes,
the composition of the electrolytes, and the frequency of the alter-
nating current [12, 17].
2. APPARATUS
(a) BRIDGE
Most of the bridge circuits of recent design for studies of sugars are
modifications of the type used by Kohlrausch [13], figure 47. The
most important change, aside from improvements in apparatus, is
that the majority read directly either in ohms or ash percentage.
The Sandera bridge [14], figure 48, although basically a Wheatstone

Polarimetry, Saccharimetry, and the Sugars 267
bridge, depends not on the variation of resistance to accomplish
balance but on the variation of the distance between electrodes.
The cell, C, and the calibration resistor, R, which remains unchanged
during any one measurement, form two arms of the bridge. The
other two arms are incandescent /\!/ –
lamps, Li and L2. These lamps are
arranged in such a manner that light
falls on opposite sides of an opaque
wedge, P. The bridge is balanced by
modifying the distance between the
electrodes of the cell until the light
reflected from the wedge is of equal R
intensity on both sides. After proper T
adjustment, the distance between the
electrodes indicates ash percentage.
CELL
(b) NULL-POINT INDICATOR
In most precision bridges, a tele- Ry
phone receiver, sensitive to the fre- FIGURE 47.—-Kohlrausch bridge
quency of the alternating current circuit for electrical conductance.
flowing through the bridge, is con- Rºº
nected as shown in figure 46 to indicate
the absence of current across CD when both the resistance and
capacitance branches are balanced.
An electron-ray tube (6E5) has been successfully employed in a
bridge circuit as a visual null-point indicator. This circuit, figure 49,
may be used at any frequency between 1,000 and 15,000 cycles, and if
the tuned circuit, Li and C13, is properly selected, it is sensitive to a
change in cell resistance of 1 part in 100,000, with a potential difference
of less than 2 volts between the bridge terminals, A and B, figure 46.
f
FIGURE 48.—Sandera bridge circuit.
Other types of indicators are those which are sensitive to frequencies
of 60 cycles or lower, as, for example, an alternating-current galvanom-
eter, milliameter, etc. Such types are particularly useful when
observations must be made in noisy surroundings. However, the
polarization reactance resulting from these low frequencies must be
ignored or compensated for in the manner described under Checking
Cells, p. 274 .

268 Circular of the National Bureau of Standards
(c) OSCILLATOR
Since the electrolytes in sugar solutions are usually of unknown
composition and may affect the electrode polarization reactance in a
different manner in different solutions, it is best to reduce this effect as
much as possible by using electrodes coated with platinum or pal-
ladium black, and employing a frequency of at least 1,000 cycles per
second. For extreme precision, measurements should be made at two
or more frequencies and values so found should be extrapolated to
infinite frequency [12, 15].
The most useful source of current to accomplish this is obtained by
using a variable-type vacuum-tube oscillator. With this source, the
frequency may be varied and errors due to bridge or cell design thus
can be detected and often eliminated.
6J 7 il C9 R13 6 E5
+ssov +zlov
FIGURE 49.-Wiring diagram of electrical conductance bridge null-point indicator.
The human ear has a practically constant sensitivity at frequencies
between 1,000 and 5,000 cycles. The oscillator should, therefore, be
capable of supplying a current at any desired frequency between these
limits if a telephone receiver is to be used as an indicator. In order to
increase the precision of bridge setting, the oscillating current should
have a pure sine wave form or be reasonably free from overtones, for
if the bridge is balanced at the fundamental frequency and there re-
main notes of other frequencies in the detector branch of the bridge
network, the sharpness of setting will be diminished and the time
required to find the minimum will be increased. Since the current
flowing through the cell heats the solution, and a potential difference
between electrodes above 1.23 volts changes the bridge balance
[12, 16, 44], the intensity and time of current flow should be reduced
as much as possible.
(d) CONDUCTIVITY CELL
Since the conductance of a sugar solution is expressed in units of
reciprocals of resistance and specific resistance has been defined as the
resistance of a column of substance 1 cm long and 1 cm” in cross-
sectional area, the specific resistance of any other column of the sub-
stance may be found from the equation
l
p=R+; (62)
or, since k=1/p, the specific conductance may be found by equation
1 l
k=#X; (63)

Polarimetry, Saccharimetry, and the Sugars 269
where R is the resistance in ohms; p, the resistivity or specific re-
sistance; k, the specific conductance; l, the length in centimeters;
and a, the uniform cross-sectional area in square centimeters. The
values of l and a are usually combined and expressed as one quantity,
l/a, which is defined as the “cell constant.” The cell constant is best
determined by measuring, in the cell to be calibrated, the resistance
of a standard solution of known specific conductance, k, substituting
in eq 63, and solving for l/a. As shown later, page 275, these
constants should be based on the resistance extrapolated for infinite
frequency [12, 16].

|5 CM.
º
FIGURE 50.-Precision-type conductivity cell.
F, Filling tubes; A, lead tubes; E, electrodes.
AS-
The cell must be so designed that the cell constant will remain
unchanged under all conditions of the experiment [12, 18]. Unless
the cell has been properly constructed, however, its constant changes
with the specific resistance and dimensions of the solution being
measured and with the frequency of the alternating current [19].
This change in cell constant with frequency (this should not be con-
fused with the electrode polarization effect), sometimes called the
Parker effect [20], results from the reactive shunts between parts of
the cell of opposite polarity in close proximity, such as the filling tubes
and lead tubes. This last factor can be made negligible by separating
these parts by about 15 cm [18], figure 50. Errors due to the Parker
effect may be expected when the “dipping type” cells, figure 51, are
used. Since the error in measurement resulting from this Parker
effect increases with frequency, and since the electrode polarization
reactance decreases with frequency, it is recommended that both be
checked by a method described below.
(e) ELECTRODES
Electrodes are usually made of platinum-iridium. They are
sometimes platinized to decrease the errors caused by the electrode
323414°—42—19
270 Circular of the National Bureau of Standards
polarization. Platinum black has the disadvantage that it is a good
catalyzer and may change the conductivity of the solution by in-
creasing the rate of oxidation of sugar therein [21]; therefore, if used,
measurements should be made as soon after filling the cell as possible.
Palladium black has less catalytic action and is considered more ef-
fective, especially at high concentrations [22].
Electrodes are platinized, in the completed cell, by filling it with
0.025 N hydrochloric acid solution containing 0.3 percent of platinum
chloride and 0.025 percent of lead acetate. A direct current of 0.010
ampere from a battery is passed through the cell, with reversal of
polarity every 10 seconds, until the amount of platinum deposited
is sufficient [23]. The platinum salt ab-
L sorbed in the electrodes should be removed
by immersing the cell for some hours in
warm distilled water which is frequently
changed. Removal of the last traces of
platinizing liquid and occluded chlorine
may be effected by placing the electrodes
in a solution of sodium acetate or dilute
sulfuric acid and passing a direct current
through the electrolyte for about 15
minutes, with reversal of direction every
minute.
2S Platinized electrodes which have dried
are wetted with difficulty, subsequently
introducing errors into the measurements
by the layer of air bubbles on the surface.
To prevent this they should be allowed to
rest in distilled water when not in use [24].
The cell constant may change slightly
with use, because of changes in the posi-
tion and surface character of the elec-
conductivity cell. trodes, and should be checked regularly
1. Leads Eclectrons, s, doctrode with a standard solution of potassium
cell immersed in solution chloride. Should it become necessary to
contained in jar. replatinize the electrodes, they may first
be deplatinized by electrolyzing aqua regia in the cells for a few minutes
reversing the current every minute. Palladium black may be re-
moved in the same manner except that hydrochloric acid is used in
place of aqua regia.
SOLUTION
~
FIGURE 51.-Dipping-type
(f) CONSTANT-TEMPERATURE BATH
Most solutions encountered in the measurement of conductivity
have a high temperature coefficient of about 2 percent per degree
centigrade. The desired precision determines the limits within
which the temperature must be controlled. Thus with a precision
of 0.02 percent, a temperature control to better than 0.01° is required.
For this precision the cell should be immersed in a well-stirred bath
with adequate regulation, and the bridge current should not produce
an appreciable heating effect.

Polarimetry, Saccharimetry, and the Sugars 271
The use of oil in the bath is preferred to water. Oil decreases the
errors caused by (1) capacitance bypaths between parts of the cell,
(2) capacitance between the cell and the walls of the bath, and (3)
electrical eddy currents in the liquid outside the cell. These errors
may amount to 0.5 percent or more [11,12].
3. PROCEDURE
(a) EQUILIBRIUM WATER
All solutions on which conductivity determinations are to be made
should be prepared from water of low specific conductance. It is pos-
sible to obtain water which has a specific conductance of 0.043×10−9
mho cm" at 18° (25). However, the instant water comes in
contact with the air, CO2 is absorbed and the conductivity increases.
When it is brought into equilibrium with the CO, in the air, preferably
by rapid aeration [26], and has no other impurities, it has a specific
conductance of about 0.85X107" [27]. It also has the pH value 5.7,
which can be readily checked with isohydric indicators [26]. (A
diaphragm pump of suitable construction is very convenient for
spraying outdoor air through a porous Alundum or fritted Pyrex
aspirator immersed in the water. Laboratory compressed air gener-
ally carries along a spray of oil and impure water.) Such water is
known as “equilibrium water.” Water having a specific conductance
greater than 3 × 10−" mho cm−" at 25° C may produce a precipitate
in the sugar solution, which would alter its conductivity. However,
it is possible to secure water of this or lower conductivity from an
ordinary laboratory still. If such water is not available, equilibrium
water may be prepared directly from tap water [27], but preferably
from distilled water, by distillation in a Jena- or Pyrex-glass vessel to
which a few milliliters of Nessler solution or alkaline permanganate
|28] has been added, and condensing the vapors in a block tin condenser.
This water is then thoroughly aerated (overnight generally sufficing)
and should be stored in thoroughly steamed and seasoned Pyrex
glass-stoppered bottles. It is quite stable over a period of several
weeks.
(b) PREPARATION OF POTASSIUM CHLORIDE solution
The potassium chloride should be selected from the purest material
available, recrystallized from conductivity or equilibrium water,
Separated by centrifugal drainage, fused in a platinum crucible, poured
into a platinum dish, and transferred to a closed bottle while still hot.
Solutions made from it should be carefully prepared according to the
following procedure: -
An approximate cell constant is estimated from a rough measure-
ment of the dimensions of the cell. From this value the concentration
of potassium chloride is selected from the recommended value in
table 33. The correct amount of potassium chloride is weighed into
a Pyrex vessel and equilibrium water is added to bring the weight to
1,000 +0.02 g. The correction to be applied to convert both the
weight of the potassium chloride and the solution to weight in vacuum
is determined according to directions found in table 114, page 632
272 Circular of the National Bureau of Standards
TABLE 33.−Specific conductance (at 1,000 cycles) of potassium chloride solutions, in
reciprocal ohm-centimeler
Rºº 1 º Specific conductance, K= ohm-1 cm-' at—
Solution Cell CODS p d 18°/4°
number 1,000 g of /
• 2- Solution in
min II].8 X vacuum, C 09 C 18° C. 20° C. 259 C.
1------------ 100 5,000 71. 3828 0.065430 0.098201 |0. 102024 0. 111733 | 1.04492
2----------- 12 600 7.43344 . 0071543 . 01 11919 . 0116676 , 0.128862 | 1.00343
3------------ 1. 3 65 0.746558 | . 00077512 . ()0122269| . 00127572 . 00141145|| 0.999.11
4------------ (). 13 6. 5 . 0.74748 |- - - - - - - - - - - - .0001.2740 - - - - - - - - - - . 00014699 . 99867
1 When the corresponding standard solutions are used in cells that have a cell constant lying between the
limits given in this column, the measured resistance will be between 1,000 and 50,000 ohms.
The specific conductances of solutions 1, 2, and 3 in table 33 were
determined by Jones and Prendergast [29]. The value for solution 4
was calculated from the empirical equations of Davies [30], which
are as follows:
A=149.92–93.85 VC-1 50C at 25°C (64)
A=129.67–79.55VC-I-35C at 18°C, (65)
where A is the equivalent conductance, and C the concentration of the
solution in moles per liter. Values calculated from these equations are
in agreement with those experimentally determined by Shedlovsky
[31], Davies [30], and Johnson and Hulett [32], at 25°C., and with those
of Shedlovsky [33], as well as Davies [30], at 18° C. The specific
conductance is determined from the equivalent conductance by
equation
k=Am, (66)
where k is the specific conductance, and m the concentration in
equivalents per milliliter (not per liter).
In order to calculate the concentration of solution 4 in grams of
potassium chloride per 1,000 g of solution, the density of a 0.001
N KCl solution at 25°C was determined by methods of interpolation
from data found in the International Critical Tables. This density
is º on a solution which contains 0.074533 g of KCl per liter
at 25° C.
(c) DETERMINATION OF CELL CONSTANTS
The resistance, Roly, of equilibrium water from the same lot as that
used in making the potassium chloride solutions is checked in a clean
cell [12, 34]. The cell is rinsed two or three times with the potassium
chloride solution and then filled therewith. It is allowed to remain 15
or 20 minutes in the constant-temperature bath. The resistance of
the solution is then determined, and redetermined at the end of 5
minutes. If the two resistances check, the solution has reached thermal
equilibrium. To verify the cleanliness of the cell, a second determina-
tion should be made after rinsing and filling it with fresh solution.
The final value of the resistance, Rson., is used to determine the cell
constant (uncorrected for solvent conductivity) by means of the
equation
(...) uncorrected —ºn. (67)
Polarimetry, Saccharimetry, and the Sugars 273
in which k is the specific conductance of a standard potassium chloride
solution (from table 33); C, the concentration in grams of potassium
chloride per 1,000 g of solution corresponding to this specific con-
ductance; and C1, the actual concentration of the solution. Both C
and Ci are expressed in grams of potassium chloride per 1,000 g of
Solution, corrected to weight in vacuum. Since the change in specific
conductance of a potassium chloride solution with concentration is
not constant, the value of C, should be made as nearly equal to C as
possible.
The uncorrected value of the cell constant, as determined from eq67,
may be used to determine the approximate specific conductance,
Ksolv., of the equilibrium water by means of the equation
I g
Rºoiv.
J
K.-() uncorrected X (68)
Since the specific conductance of the solution, Kson., is the sum of the
specific conductance of the potassium chloride ions, Kkol, plus the
specific conductance of the ions present in the equilibrium water,
Ksolv., a very close approximation of the cell constant may be calculated
from the equation
l O
}=(K% +kº)”. (68a)
A more accurate method would be to make two resistance measure-
ments, R' and R'', extrapolated for infinite frequency, on two stand-
ard solutions of known specific conductance, K' and K’’. Then
l / // 1 |
:= (K' –K (#-F#) (68b)
(l,
All measurements should be made at the temperature and frequency
corresponding to that at which the conductance values of the standard
potassium chloride solution were determined.
The cell constant, (l/a), at any temperature, t, may be computed
from the cell constant, (l/a)0, at 0°, according to the following equation
[35]:
()–()0–20, (69)
where o is the linear coefficient of expansion of the glass from which
the cell is constructed. For Jena normal 16 III glass, oſ-8.08×10"
[36], and for Pyrex glass, oſ-3.6×10" [37].
Cells should be selected which have constants of such values that
the total measured resistance of solutions of the electrolytes will
lie between the limits of 1,000 and 50,000 ohms [35]. The highest
resistance of any of the solutions measured will be that of equilibrium
water, which should have a specific conductance not greater than
3.0}< 107" and the lowest resistance, that of molasses, which may
have a specific conductance as high as 5X10^*. Three cell constants
will cover this range and yet fall within the limits of resistance given
above. These are 0.15, 7.5, and 50.0 reciprocal centimeters. If the
specific conductance covers a narrow range, a single cell may suffice.
274 Circular of the National Bureau of Standards
(d) CHECKING OF CELLS
The best test for the quality of the cells, whether they have bright
or platinized electrodes, and for sufficiency of platinization, is to note
the change in resistance resulting from a change in frequency of the
oscillator current [38].
If electrode polarization reactance be treated as a function of the
frequency, it follows that this reactance may be determined by
successively measuring the resistance of the solution at two frequencies,
W 1–1–1 I-I u 1–I- M I I-I-I r—I-I
5.00H - *
.O
O
}=mº.
O.I.O
700 CYCLES PER SECQND ==
O
.O
3O7O CYCLES PER SECOND
.OO! ————l—H–
5 |O 15
PLATINIZING CURRENT IN COULOMBS PER SQCM
FIGURE 52.-Polarization reactance versus platinization.
one of which is about four times as great as the other. Whenever the
difference between these two measurements is negligible for the pur-
pose of the measurement, then the deposit of platinum black is
adequate. (Fig. 52 [17] shows how the platinization of electrodes
reduces this reactance.) However, if the two measurements indicate
that a correction should be made, the true resistance may be found by
extrapolating the data to infinite frequency [12, 15]. This may be
done graphically or in the following manner:
Let R, and R, be the resistance measurements at two frequencies,
f, and f, respectively. Then, if the electrode polarization reactance,

Polarimetry, Saccharimetry, and the Sugars 275
AR, is inversely proportional to some function, m, of the frequency
Ol' . AR= k/f"
where k is the proportionality factor. The true resistance, Rr, of the
solution is equal to the measured resistance minus the electrode
polarization reactance or
R4 = R, – AR = R2– AR,
Rz-R-k/f;=R,-k/fº,
OI’
from which
R1–R.
k = l_l (71)
f* f.
and
R-R-## (72)
1-()
f
Early observers have used unity for the value of m [15], but in a
recent investigation 1/2 has been used [17]. It must be remembered
that the use of the above equations is valid only when other errors in
measurement resulting from changes in frequency (such as from the
Parker effect) have been eliminated.
When routine measurements, such as those encountered in factory
operations, are being made, no correction for electrode polarization
reactance need be estimated. The frequency used for the observation
should be recorded if it is to be compared with other data.
4. SPECIFIC CONDUCTANCE OF SOLUTIONS OF SUGAR PRODUCTS
(a) ASH DETERMINATION BY THE “C-RATIO” METHOD
“C-ratio” is defined as the ratio of the percentage of ash determined
by incineration, as in chapter XVI, p. 263, to the specific conductance.
After this factor has been established by averaging the results of several
determinations of gravimetric ash and specific conductance, it may
then be used to determine the percentage of ash of similar products by
substituting its value and measured values of specific conductance in
the equation
Percentage of ash– C-ratio X specific conductance. (73)
This method of determining ash is applicable to control work of
individual sugar manufacturers and to the ash analysis of granulated
and other refined sugars [39]. However, since the specific-conductance
value alone may be used to predict the performance of the product,
º prefer to use it without conversion to percentage ash for control
WOI’K.
276 Circular of the National Bureau of Standards
Specific-conductance determinations are made in cells of predeter-
mined cell constant at a temperature most convenient for the locality,
by measuring, as described above, the resistance of a solution of the
product in equilibrium water and substituting this value in eq 63.
The value of the specific conductance of the equilibrium water should
be subtracted from the value found for the solution before the cal-
culation of the C-ratio is made.
If the solutions are heated or subjected to vacuum, the value of
Ksoly will be changed from loss of CO2; if high precision is required,
the value of Koly should be redetermined on a sample of the equilib-
rium water treated in the same manner as the solution.
The concentration of the solution recommended by different
observers varies from 2.5 g of dry substance per 100 ml to 50 g per
100 ml. Since the conductivity of solutions of beet-sugar products
passes through a maximum at 25 g of sucrose per 100 ml of solution [8],
measurements made near this concentration will be affected less by
slight errors in concentration than at other concentrations [40].
Regardless of what concentration is selected as being the most suitable,
it should be the same as that used for the determination of the C-ratio.
(b) ZERBAN AND SATTLER CONDUCTANCE METHOD FOR ASH
Although the C-ratio method may be used to determine the ash
content of sugars from the same source in any one season, the ratio
determined for one district cannot be used for another district. This
fact has resulted in the Zerban and Sattler method for ash determina-
tion, based on conductivity measurements under special conditions,
and no reference need be made to the gravimetric ash,
In developing this method, they minimize all causes for variability
of the C-ratio except that resulting from the composition of the dis-
Solved salts. The inorganic salts in solution in raw sugars are prin-
cipally sulfates and chlorides. Since the equivalent conductance of
solutions containing anions of inorganic salts is considerably higher
than that of solutions containing anions of organic salts derived
from the same base, it follows that the specific conductance of a solu-
tion containing a large percentage of chlorides or sulfates in the ash is
relatively greater than that of a solution containing a small percentage.
Furthermore, the C-ratio will decrease as the percentage of inorganic
anions in the ash increases.
If hydrochloric acid is added to a solution containing only inorganic
anions, the specific conductance will increase linearly with the addition
of acid. However, if the solution contains both organic and inorganic
anions, the specific conductance will increase linearly only after the
weaker inorganic anions have been displaced by those of the added
acid.
A similar relationship exists between the specific conductance of
solutions containing inorganic and organic cations if a solution of
potassium hydroxide is added. However, except when the sugar
product has received treatment with bone black, this latter relation-
ship is not pronounced and may be ignored.
From these relationships, Zerban and Sattler have developed three
general methods for the determination of ash applicable to:
1. Raw cane and soft sugars [41].
Polarimetry, Saccharimetry, and the Sugars 277
2. Refinery sirups and molasses produced without char treatment
[42].
3. Raw and refinery sirups and molasses of unknown origin [43].
(1) RAw CANE AND SOFT SUGARs [40].-Twenty-five grams of sugar
is dissolved in equilibrium water and the solution diluted to 500 ml
at 20° C. The specific conductance, k, of one portion of this solution
is determined and likewise, the specific conductance, ki, of another
portion to which 5 ml of 0.25 N hydrochloric acid has been added to
each 200 ml. Corrections are made for temperature and the con-
ductivity of the water. The corrected specific conductances multi-
plied by 10° give, respectively, K for the original solution, and K, for
the acidified solution. The percentage of ash may then be computed
from the empirical equations,
Raw sugar, percentage of ash–0.001757). (0.913K-H 193.5–0.1K)
- (74)
Soft sugar, percentage of ash–0.001695). (0.913K-H 193.5–0.1K)
(75)
The temperature corrections for k and ki are given by the equations
(k) = (k)20 [1+0.02234 (t–20)-H0.0000885 (t–20)* (76)
(k1),= (ki)261–H 0.01704 (t–20) +0.000062(t–20)*], (77)
in which t is the temperature at which the conductivity determination
is made. The correction for (k), is roughly 2.2 percent per degree
centigrade if measurements are made near 20° C.
The concentration of the acid may be checked by conductivity
determinations. When 5 ml of the 0.25 N acid is mixed with 200 ml
of ºrium water the corrected specific conductance is 0.002370
at 20° C.
(2) REFINERY SIRUPS AND MOLASSES PRODUCED WITHOUT CHAR
TREATMENT [41].-A solution is made of 100 ml of hot equilibrium
water and 25 g of sirup or molasses. It is filtered with vacuum through
asbestos and filter-paper pulp into a 200-ml volumetric flask with
repeated washing with hot equilibrium water. The filtrate is mixed
thoroughly and diluted with equilibrium water to 200 ml at 20° C.
To a 20-ml portion of the filtrate is added 22.5 g of pure tablet sugar.
This is diluted to 500 ml at 20° C with equilibrium water. This is
known as solution A. To 200 ml of solution A, 5 ml of 0.25 N hydro-
chloric acid is added. This is known as solution B.
The specific conductances are determined in both solutions A and
B and are corrected for solvent, specific conductance of the tablet
Sugar, and temperature. These values multiplied by 10° are re-
Spectively K and K1, which may be substituted in the equation
Percentage of ash–0.001757 (9.13K+ 1935–Kı). (78)
(3) RAW AND REFINERY SIRUPS AND MOLASSEs of UNKNOWN
ORIGIN [42].-The procedure is the same as that used for the preceding
determinations except that three conductivity measurements are
required. Normal orthophosphoric acid is added to solution A to
obtain solution B. The specific conductance at 20° C is determined
on each of the following solutions:
1. k of solution A, as prepared in the preceding section.
278 Circular of the National Bureau of Standards
2. ki of solution A, to which has been added 5 ml of 0.025 N potas-
sium hydroxide per 200 ml.
3. kg of solution A, to which has been added 5 ml of normal ortho-
phosphoric acid per 200 ml.
Each of the three specific conductances so determined are corrected
for the specific conductance of the equilibrium water used and for the
specific conductance of the tablet sugar. The corrected values
multiplied by 10° are respectively K, K2, and Ks. The percentage of
ash is then determined by substituting these values in the equation
Percentage of ash–0.0191369|K–0.002249A3–0.001210 K3-I-3.07.
79)
The concentration of the acid may be checked by conductivity
determinations. When 5 ml of the normal orthophosphoric acid is
added to 200 ml of equilibrium water the corrected specific conductance
is 1925). 10-0 at 20° C.
5. REFERENCES
[1] Hugh Main, Int. Sugar J., 11, 334–9 (1911).
[2] A. E. Lange, Z. Ver. deut. Zucker-Ind. 60, 359–81 (1910).
[3] F. Toedt, Chem.-Ztg. 49, 656–7 (1925).
[4] R. Sandera, Listy Cukrovar. 48, 312–5 (1930; J. Peller, Listy Cukrovar. 49,
76–80 (1930); O. Spengler, F. Toedt, and J. Wigand, Z. Ver. deut. Zucker-
Ind. 82, 789–816 (1932); 83, 822–32 (1933); 84, 93–111 (1934); 84, 443–9
(1934); 84, 789–805 (1934); P. Honig and W. F. Alewijn, Arch. Suikerind.
III, Mededeel. Proefsta. Java-Suikerind. (1932); 1811–224 A. Courriere,
Betterave 42, 17–19 (1932); 44, 5 (1934).
[5] K. Sandera, Listy Cukrovar. 48, 312–5 (1930).
[6] V. Netuka, Listy Cukrovac. 46, 564–6 (1928).
[7] K. Sandera, Z. Zuckerind Cechoslovak. Rep. 53, 378–82 (1929).
[8] A. R. Nees, Ind. Eng. Chem. (Ind. Ed.) 19, 225–6 (1927).
[9] J. H. Zisch, Facts About Sugar 25, 741–6 (1930).
[10] V. Dejmek and F. Stern, Listy Cukrovar. 53, 353–6 (1935); Z. Zuckerind.
Cechoslovak. Rep. 59, 417–21 (1935).
[11] G. Jones and R. C. Josephs, J. Am. Chem. Soc. 50, 1049–1092 (1938).
[12] W. A. Taylor and S. F. Acree, Science, 44, 576–578 (1916).
[13] F. Kohlrausch and L. Holborn, Leitvermögen der Electrolyte (B. G. Teubner,
Leipzig, 1898).
[14] K. Sandera, Chimie & industrie, 651, Special No. May, 1927.
[15] W. A. Taylor and S. F. Acree, J. Am. Chem. Soc. 38, 2415–2430 (1916).
[16] W. A. Taylor and S. F. Acree, J. Am. Chem. Soc., 38, 2396–2403 (1916).
[17] G. Jones and S. M. Christian, J. Am. Chem. Soc. 57, 272-280 (1935).
[18] G. Jones and G. M. Bollinger, J. Am. Chem. Soc. 53, 411–451 (1931).
[19] M. Randall and G. N. Scott, J. Am. Chem. Soc. 49, 639 (1927); F. A. Smith,
J. Am. Chem. Soc. 49, 2167—2171 (1927).
[20] H. C. Parker, J. Am. Chem. Soc. 45, 1366, 2017 (1927).
[21] F. W. Zerban and L. Sattler, Facts about Sugar 21, 1158–1162 (1926).
[22] J. Reilly and W. N. Rae, Physico-Chemical Methods, p. 707 (D. Van
Nostrand Co., Inc., New York, N. Y.) 1932.
[23] G. Jones and D. M. Bollinger, J. Am. Chem. Soc. 57, 280–284 (1935)
[24] C. W. Davies, The Conductivity of Solutions, 2d. ed., p. 56 (John Wiley &
Sons, Inc., New York, N. Y., 1933).
(25] F. Kohlrausch and Heydweiller; Z. Physik. Chem. 14, 326 (1894).
(26] Edna H. Fawcett and S. F. Acree, J. Bact. 17, 163—204 (1929).
27] J. Kendall, J. Am. Chem. Soc. 38, 2460–2466 (1916).
[28] Fºrºn and L. Sattler, Facts about Sugar 21, 1158–1159, 1162–6
1 ->
[29] G. Jones and M. J. Prendergast, J. Am. Chem. Soc. 59, 731–736 (1937).
[30] C. W. Davies, J. Chem. Soc. 59, 432–436 (1937).
[31] Theodore Shedlovsky, J. Am. Chem. Soc. 54, 1424 (1932).
[32]. C. R. Johnson and G. A. Hulett, J. Am Chem Soc. 57, 258 (1935).
[33] Theodore Shedlovsky, J. Am. Chem. Soc. 54, 1410 (1932).
Polarimetry, Saccharimetry, and the Sugars - 279
| W. A. Taylor and S. F. Acree, J. Am. Chem. Soc. 38, 2403–2415 (1916).
| G. Jones and B. C. Bradshaw, J. Am. Chem. Soc. 55, 1791 (1933).
[36] H. Thiene, Glas, p. 130, (G. Fischner, Jena, Germany, 1931.)
| C. G. Peters and C. S. Cragoe, Sci. Pap. BS 16, 449 (1920) S393.
] G. Jones and D. M. Bollinger, J. Am. Chem. Soc. 57, 280–284 (1935).
| F. W. Zerban and L. Sattler, Ind. Eng. Chem., Anal. Ed. 3, 43 (1931).
| H. Lunden, Centr. Zuckerind, 33, 204–5 (1925); B. Lazar, Listy Cukrovar.
49, 480–5 (1931); M. Sanderova and K. Sandera, Listy Cukrovar. 53,
389–6 (1935); F. Majer, Listy Cukrovar, 54, 341–5 (1936).
F. W. Zerban and L. Sattler, Facts about Sugar 22, 990–994 (1927).
F. W. Zerban and L. Sattler, Ind. Eng. Chem., Anal. Ed. 2, 32–35 (1930).
F. W. Zerban and L. Sattler, Ind. Eng. Chem., Anal. Ed. 3, 38–40 (1931).
S. F. Acree, Edward Bennett, G. H. Gray, and Herald Goldberg, J. Phys.
Chem. 42, 871–896 (1938).
XVIII. MEASUREMENT OF HYDROGEN-ION
CONCENTRATION
1. INTRODUCTION
Bates and Associates [1] in 1920 reported results giving the hydrogen-
ion concentration of aqueous solutions of a number of commercial
Sugars. In 1922 Brewster and Raines [2] published an account of the
use of hydrogen-ion methods for reaction-control in cane juices in
the experimental manufacture of sugar. Balch and Paine [28] in
1925 described a scheme for the automatic recording of hydrogen-ion
concentration in lime-treated cane juice. These appear to be the
earliest recorded instances of the application of such methods (now
regarded as indispensable) to commercial sugar products and their
manufacture. These were followed shortly by the development of
apparatus for the automatic dosage of cane or beet juices with lime
or carbon dioxide to a desired end point controlled by electrodes
reacting to the pH of the liquid, the resulting pH being simultaneously
recorded. .
Prior to the advent of hydrogen-ion methods, the adjustment of
reaction in sugar juices was based upon the titration of a quantity
with standard acid or alkali to an indicator end point. This gave a
measure of the quantity of acid or alkali present. Hydrogen-ion
methods, on the other hand, give information regarding the intensity
of reaction of acid or alkali due to the concentration of hydrogen (or
hydroxyl) ions, which influence the rate of inversion of sucrose, and
the clarification, filtration, and decolorization of juices, as is well known.
The nomenclature of hydrogen-ion concentration is based upon the
normal weight (1.008 g) of ionized hydrogen in a liter of solution. This
may be expressed fractionally as 1/1 N. A solution containing 0.01008 g
of hydrogen ions per liter would be 1/100 N, and so on. If these
fractions are expressed as powers of 10, we have 1/1 = 10", 1/10=107",
1/100 = 10^*, . . . 1/1,000,000–107", and so on. The negative
exponent, which may or may not be a whole number, is the logarithm
of the reciprocal of the hydrogen-ion concentration, log 1/[H+] (the
brackets indicate normality). To this has been assigned the symbol
pH. The numerical value of pH is sometimes called the hydrogen-ion
exponent. Instead of using fractions, we therefore write pH = 1,
pH=6, pH=8.4, etc. Also one may say that the pH value of a
solution is the logarithm of the number of liters that contain 1 gram-
ion of hydrogen. Thus in pure water, at the ordinary temperature, it
requires 10 million liters to yield 1.008 g of ionized hydrogen. The
log of 10,000,000 is 7. Therefore the pH of pure water is 7.
280 Circular of the National Bureau of Standards
In all neutral aqueous solutions, as well as in pure water, pH-i-
pOH = 14 at the ordinary temperature, and the products of disso-
ciation, H+ and OH− ions, are present in equal amounts, so that
pH=p0H=7. The expression, pCH, which might be taken for the
purpose of expressing alkalinity, ordinarily is not used, since, as may
be seen by reference to the two equations, values of pH below 7 indi-
cate an excess of Ht over OH− ions, and the solution is said to be
acid. Similarly, when pH values are above 7, the OH− ions are in
excess and the solution is said to be alkaline.
The so-called strength of a pure acid or alkali in solution depends
upon the degree of ionization and the hydrogen-ion concentration of
such solutions may be calculated from the ionization constant. If a
strong acid or alkali be added little by little to water, the hydrogen-ion
concentration changes enormously with each addition. If, however,
a soluble salt of the acid or base be present, the ionization is depressed
and upon the addition of the one or the other the change in hydrogen-
ion concentration is gradual and may be controlled within certain
limits. This resistance to change in pH due to the presence of a salt
is called buffer action. Buffer action also results from the presence
of salts of bases with weak acids as encountered in most plant juices
and accounts for the very gradual increase in hydrogen-ion concen-
tration of cane juice when the latter is treated with sulfur dioxide.
Advantage is taken of the buffer action of certain salts in the prepara-
lº of standard solutions for colorimetric pH methods, as described
ater.
Methods for the measurement of hydrogen-ion concentration may
be divided into two categories (a) potentiometric methods, whereby
is measured, under proper conditions, the potential of a concentration
cell, of which the unknown solution is a part, and (b) colorimetric
methods depending upon the use of indicators, the color or shade of
color of which changes with variation in hydrogen-ion concentration.
It is advantageous to have both potentiometric and colorimetric
methods available.
2. POTENTIOMETRIC METHODS
(a) POTENTIOMETERS
The electromotive force (emf) of a concentration cell is measured
by balancing against it a measurable potential from an external
source. At balance no current passes through the cell, as indicated
by the null-point instrument. The apparatus employed consists of
a potentiometer; a galvanometer as indicating instrument; an outside
source of emf, such as that furnished by dry cells or a storage cell,
the value of which is known by reference to a standard cell, the last-
named being usually a Weston cadmium-mercury cell.
Potentiometers are available in several forms, some of which are
highly accurate and used in research and for calibrating other instru-
ments. Others intended for industrial laboratory and plant use,
although having sufficient accuracy, are portable, with galvanometer,
standard cell, and measuring device in a single housing, or with all
accessories, including glass and reference electrodes, amplifying tubes,
and voltage supply housed within a small space. The choice of appa-
ratus is dictated by the accuracy required and by the nature of the
material in which measurements are to be made.
Polarimetry, Saccharimetry, and the Sugars 281
A diagram of the Leeds & Northrup type K potentiometer is shown
in figure 53, which, with the description that follows, illustrates the
potentiometric principle and the operation of the instrument. In
figure 54 the instrument is shown in use with a hydrogen gas-calomel
cell. The standard cell, galvanometer, and dry cells also are shown.
. In the diagram the portions of the bridge by which measurements
are made consist of fifteen 5-ohm coils in series in the circuit AD
(contact made with M), and in series with them the extended wire
DB, the resistance of which is also 5 ohms. The scale of DB, shown
in the photograph, reads from 0 to 1,100. Contact with the extended
wire is made by the moving contact, M'. Current from the battery,
W, flows through these resistances and may be made exactly 0.02
ampere by means of the regulating rheostat, R. This is done by
setting the double-throw switch to “stol. cell”, which connects the
standard cell in series with the galvanometer, G, and the tapping keys,
+6% &-
FIGURE 53.−Wiring diagram of type K potentiometer
GA.
Courtesy of I.eeds & Northrup Co.
R1, R2, and R3, and with the point .5 on AD, to which one point on the
double-throw switch is wired. Between A and 0 there is a series of
resistances with a sliding contact, T. The resistance between the
points .5 and A is exactly that which corresponds with the emf of 1
volt, and between 1.0166 and .5 a sufficient resistance is added to make
the resistance between these points correspond exactly with an emf
of 1.0166 volts. The small circular slide wire connected at 1.0166
makes contact with the standard cell through the contact, T. The
resistance value of this slide wire is such that a practically continuous
variation can be obtained in the standard-cell circuit voltages from
1.0166 to 1.0194, a range corresponding with the variations in different
standard cadmium cells. To adjust the current to 0.02 ampere, with
the switch thrown to the “stol. cell” position, the contact, T, is set to
correspond with the standard cell voltage and rheostat, R, is regulated
until the galvanometer shows no deflection. The unknown emf is

282 Circular of the National Bureau of Standards
now measured by throwing the switch to the emf position and adjusting
the resistances with M and Mº by touching the contact keys, R., R.,
and R, until there is again no galvanometer deflection. After this
measurement is made the working current may again be checked
against the standard cell, as described.
In figure 55 is shown a Leeds & Northrup potentiometer-electro-
meter with range from 0 to 1.100 volts. This portable instrument
contains a stage of amplification and is suitable for pH measurements
Courtesy of Leeds & Northrup Co.
FIGURE 54-Leeds & Northrup type K potentiometer with hydrogen-gas electrode,
calomel electrode, etc.
with all types of electrodes, including glass. Other types of poten-
tioneters are illustrated in figure 59, A and B.
(b) CALOMEL ELECTRODES
Various forms of calomel electrode vessels are shown in figure 56.
The bulb at the bottom of the cell (C, D, E) is filled with a layer of
pure mercury. On this rests a layer of pure calomel mixed with
mercury, and the filling of the cell is completed with a solution of
potassium chloride having a definite concentration and saturated with
calomel. One of three concentrations of potassium chloride is custom-
arily used, either 0.1 M, 1.0 M, or saturated, and in reference to these
concentrations the terms “tenth-normal”, “normal”, or “saturated”
calomel electrodes are used as abbreviations. By means of side-tubes
the cells communicate with a reservoir of saturated potassium chloride
which by turning the stopcock at the top of the cell may be allowed to
fill the side arm and form the necessary salt bridge between the calomel

Polarimetry, Saccharimetry, and the Sugars 283
electrode and the unknown solution. Electrical connection between
the electrode and the potentiometer is made through platinum wire
sealed into the bottom of the vessel and either wired directly, as in D,
or through a short column of mercury in the small glass tubes sealed
at the bottom of the electrode (C and D). In the dipping electrodes,
Courtesy of Leeds & Northrup Co.
FIGURE 55.-Potentiometer-electrometer.
A and B, the calomel electrode proper is contained in the small
inner tube, which, near the bottom and just above the calomel layer,
has a small opening through which the electrode communicates with
the potassium chloride solution contained in the outer jacket. This
i
|
|
i
-
|
A B C D E
FIGURE 56.--Types of calomel electrodes.
jacket is closed by a ground joint which is moistened with potassium
chloride solution which passes the current when immersed in the
test solution.
It is essential that pure materials be used in preparing the electrodes
in order that they may have the accepted emf values. Mercury may
be purified by allowing it to fall in a fine spray through diluted nitric


284 Circular of the National Bureau of Standards
acid. It is then washed with distilled water, dried, and distilled in
vacuo. Reilly and Rae [4] give the following directions for purifying
mercury by electrolysis: “The mercury is placed in a large dish inside
which is a small dish containing a small quantity of mercury. Plati-
num-wire electrodes sealed into glass tubes make contact with the
two portions of mercury, that in the smaller vessel being the cathode.
An electrolyte, consisting of 90 parts of water, 5 parts of sulfuric acid,
and 5 parts of nitric acid, is poured in so as to cover the upper edge of
the smaller vessel to a depth of 2 cm. A current of 0.5 ampere is
passed for 2 hours for each kilogram of mercury in the outer vessel.
The mercury in the outer vessel is then removed, washed, dried, and
distilled in vacuo.”
For the preparation of calomel a portion of the purified mercury is
dissolved in pure nitric acid that has been redistilled and slightly
diluted. The mercury nitrate solution is poured into a large excess
of distilled water containing some nitric acid. To this solution is
slowly added dilute hydrochloric acid purified by distilling pure 20-
percent acid, discarding the first and last portions of the distillate.
The precipitate is repeatedly washed with distilled water, preferably
by decantation. Some free mercury should be present throughout
the process to prevent the formation of mercuric salt. At the com-
pletion of washing, the calomel should be intimately mixed with finely
divided mercury by shaking.
TABLE 34.—Arbitrarily standardized values for half-cells
Half-Cell I.------------------------------------ |(H+)=1|H2 (1 atm), Pt
Half-Cell II----------------------------------- KCl (sat.) | KCl (0.1 N), HgCl Hg.
Half-cell III---------------...------------------- RCl (Sat.), HgCl) Hg.
Half-Cell IV----. --- - - - - - - - - - - - - - - - - - - - - - - - - - - - KCl (Sat.)|HCl (0.1 N)|H2 (1 atm), Pt.
Half-Cell V------------------- ---------------- RCl (Sat.) K. º: Ç M)|H2 (1 atm), Pt.
Cetic aci .1
Half-cell VI---------...------------------------- RCl (Sat.) Na acetate (0.1 M) H2(1 atm), Pt.
Half-Cell VII--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - |(H+) = 1, quinhydrone|Pt.
Balf-cell VIII--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - KCl (Sat.) | HCl (0.1 N), quinhydrone|Pt.
Tem- Half-cell
pera-
ture
II III IV V VI VII VIII
o C, Volts Volts Volts Volts Volts Volts Volts Volts
18 0.0000 0.3380 (). 251 –0, 0621 (–0. 229) –0. 2668 (). 7044 0.6423
20 . 0000 . 3379 . 250 —. 0625 —. 2310 — . 2686 . 7029 . 6404
25 . 0000 . 3376 . 2458 —. 0636 (—. 235) —. 2732 . 6992 . 6356
30 . 0000 . 3371 . 242 — . 0647 (–. 239) || - - - - - - - - - - - - , 6955 . 6308
35 . 0000 . 3365 . 238 –.0657 |- - - - - - -------|------------- , 69.18 . 6261
38 . ()000 . 3361 . 236 -. 0664 || - - - - - - - - - - - - - - - - - - - - - - - - - . 6896 . 6232
40 . 0000 . 3358 . 234 –. 0668 - - - - - - - - - - - - | . . . . . -------- . 6881 . (52.13
1 W. M. Clark, The Determination of Hydrogen Ions, 3d. ed., p. 672 (Williams & Wilkins Co., Balti-
more, Md., 1928).
The calomel-mercury mixture, before being placed in the vessel, is
repeatedly shaken with small quantities of the potassium chloride
solution chosen for the cell. The potassium chloride solution used
to complete the filling of the cell is also saturated with calomel.
The calomel half-cell may be connected directly with the test solution
or through a salt bridge formed usually by a saturated solution of
potassium chloride flowing from a reservoir through a side arm of
the vessel and making contact with the calomel-saturated potassium
chloride of the cell. After a measurement, the solution at the end
of the side arm may be flushed out by slightly turning the stopcock.
Polarimetry, Saccharimetry, and the Sugars 285
In electrodes A and B (fig. 56) the larger outside tube contains
saturated potassium chloride and the inner tube is the calomel elec-
trode proper.
Clark’s [3] table of values for several half-cells commonly used in
the determination of hydrogen-ion concentration is reproduced in
table 34. It is pointed out by Clark that discrepancies may be
found in certain values given in the table and that certain values are
to be regarded as tentative. This applies particularly to the tem-
perature error in the saturated calomel half-cell. “On the other
hand, the potential of a cell composed of a hydrogen or quinhydrone
half-cell and a saturated potassium chloride calomel half-cell has a
small temperature coefficient . . . so that the temperature value
may be in considerable error without causing great error in potential.”
(c) HYDROGEN ELECTRODES
A hydrogen electrode is formed by saturating platinum black
(coated on platinum foil or wire for rigidity) with hydrogen gas.
When such an electrode is placed in contact with a solution containing
hydrogen ions, a difference of potential is established at the electrode-
solution interface analogous to the potential difference between a
metal electrode and a solution containing its ions. The emf of such
a half-cell is not directly measurable, but if two half-cells be con-
nected so that the electrolytes form a sharp liquid junction, the total
emf of the concentration cell so formed may be measured potentiomet-
rically. If the emf of one half-cell is known, that of the other may be
computed.
The emf of such a concentration cell, ignoring the liquid-junction
potential, is represented by
_RT 1, C
E=# Il O'
where R is the gas constant=8.31507 volt-coulombs in absolute
units; T is the absolute temperature=273.1+tº C; n is the valency
of the electrode element; and F (the faraday) is the charge on 1 g
equivalent of the ion=96,500 coulombs. C and Ci are the ion con-
centrations in the two halves of the cell. Substituting and multiply-
ing by 2.3026 to convert to common logarithms, we obtain
- T', C.
E=0.000198406; log C.'
Since measurements of E are customarily made in terms of inter-
national volts instead of absolute units, the numerical value in eq
81 is converted by dividing by 1.00042 [3, p. 250], and we obtain
T O
m log C.’ (82)
| (80)
(81)
E=0.000198322
For the hydrogen electrode, let us assume that the concentration in
one of the half-cells is normal with respect to hydrogen ions (1.008
g/liter) and write C=1, and in the other half-cell let the hydrogen-ion
concentration be unknown and write C1 =[H+]. The valence, n=1,
and eq 82 then becomes
E=0.000198322T log º (83)
323414°–42—20
286 Circular of the National Bureau of Standards
.. 1 12 vizc 7 ſ
and since log [H+]#-pH, we have
E
P*-0000ſ,5355T (84)
Or at 25° C
E
PH=00553. (85)
The normal hydrogen half-cell is not used as a reference standard
in practical pH measurements. As a primary standard of reference,
Clark [3, p. 480] recommends the 0. 1 N calomel half-cell, referred to
the potential of the normal hydrogen half-cell as equal to zero, and
specifies as follows:
“It shall be assumed, arbitrarily, that in the cell Pt, Hg (1 atmos.)
|H+ (activity, *kc. ºntºc (0.1 N), HgCl(sat.) |s the po-
A
tential difference at B remains constant as a varies and that the sum
of the potential differences at B, C, and D is as follows at each in-
dicated temperature. [These values are given in table 34, column 2.]
“The standard experimental meaning of pH shall be the potential
of the above cell considered as of positive numerical value, less
the above value for the calomel half-cell pertaining to the temper-
ature used, the difference being divided by the numerical quantity
0.000198322T, where T is the absolute temperature.”
The statement of the last paragraph may be formulated in the
equation
pH= E— E(cal)
T0.0001983227' (86)
This does not preclude the use of secondary standards, such as the
saturated calomel half-cell or the quinhydrone electrode, but the
“attempt shall be made to use this standard in accordance with the
specifications made above.”
Hydrogen-electrode potentials vary with barometric pressure, and
the apparatus should be so constructed that the gas pressure in the
half-cell is the same as that of the surrounding atmosphere. In most
routine measurements, a barometric correction may be omitted, but
it should be included for exact measurements. The corrected value
of pH is obtained by
H_{i-1} (bar.) – E (cal)
P*T TO.00019s;257.
y
and the correction value E (bar.) is found by
0.000198322T
2
760
E (bar.)= log ---,
12 Clark [3, p. 479] states: “Originally ph was defined by pH = log Hi Actually the numerical values
called pH have been determined by dividing the potential of a hydrogen cell by 2.3026 RT/F. In the
comparison of one solution with a standard solution of hydrion activity of unity, the rigid relation may
be written
lo 1___ – EF
* (HF) 73.3035ET’
where (H+) represents the hydrogen-ion activity of the solution under investigation. Consequently, the
measured values called pH are log d; +) .”
Polarimetry, Saccharimetry, and the Sugars 287
where w is the value found by Subtracting the pressure of aqueous
vapor at the temperature, tº C, from the barometer reading.
The hydrogen electrode is used for the standardization of buffer
Solutions and for checking methods in which other electrodes are used.
It is useful in properly buffered solutions over a range of 0.0 to 14.0
pH. It is inaccurate in the presence of certain metals and dissolved
gases and in the presence of sulfites or sulfurous acid. The coating of
platinum black is sometimes clogged or “poisoned” and rendered
inactive.
The Clark rocking-electrode assembly, consisting of hydrogen and
calomel electrodes, is shown in detail in figure 57, and mounted for
use in figure 58 (E). The hydrogen electrode vessel, shown at E
(fig. 57) is mounted in a clamp pivoted behind the rubber connection
between J and H. This clamp runs in a groove of the eccentric, I, the
#
=
-*E-—T-
=—
#
FIGURE 57.-Clark rocking electrode.
rotation of which rocks the vessel. With the hydrogen electrode
inserted at F, the vessel is filled as full as possible with water from D
through cock C. The water is displaced with hydrogen through A
after turning C to communicate with drain, B, and the vessel is
flushed with succeeding changes of hydrogen. The vessel is rocked
back toward C, which is closed, and the test solution is run in from
reservoir, D, with G open toward B' until the vessel is half full.
Cock G is now closed and cock C is opened so that hydrogen may
enter through A to exert a continuous pressure on the liquid. The
solution is then rocked until equilibrium is established with the liquid.
The rocking alternately completely immerses and then exposes the
electrode to the hydrogen gas.
At M is a saturated potassium chloride—calomel electrode used as a
working standard, and at N is a reservoir containing saturated potas-
sium chloride used in making liquid junctions. At P is a battery of
accurately made 0.1 N calomel electrodes used in standardizing the
saturated calomel working cell. This battery may be connected with
the system through the liquid junction at 0 by opening cock K. To
measure the emf, the rocking is stopped, and E is opened so that a
Small amount of saturated potassium chloride may escape through





288 Circular of the National Bureau of Standards
B’ while the rubber tube between J and H is pinched. Cock E is
turned so that E and H communicate and liquid flows into H to form
a liquid junction with the saturated potassium chloride salt bridge.
Measurement is made with the potentiometer to give a combined
emf for the entire chain which, let us assume, is 0.645v at 25°C. The
emf of the saturated calomel half-cell and potassium chloride salt
bridge at 25°C, as given by Clark, is 0.2458w. Then
H_0.645–0.2458
Prº-O.050T5
=6.92,
the barometric correction being ignored.
Simpler forms of hydrogen electrodes that are satisfactory are
illustrated in figure 58. Electrodes A and C are made of platinum
º
i
_ſſ
A B C D E
FIGURE 58.-Various types of hydrogen electrodes.
A, B, C, D, dipping electrodes; E, rocking electrode.
Courtesy of Leeds & Northrup Co.
wire and foil, respectively, sealed into glass tubing, contact with the
wire leading to the potentiometer being made through mercury
contained in the tubing. At B and D are shown the electrodes in
glass jackets which are connected with the supply of hydrogen gas by
rubber tubing fitted to the side arm. Hydrogen under slight pressure
bubbles from the bottom openings of the jacket, alternately bathing
the electrode with hydrogen and with solution. When the solution
has become saturated with hydrogen, the flow of gas is stopped and
the emf is measured.
For the deposition of platinum or palladium black on bright plati-
num, Clark electrolyzes a 3-percent solution of the chloride of either
metal, acidified with hydrochloric acid. The current from a 4-volt
storage battery is allowed to produce a vigorous evolution of gas until
the coating of black conceals the glint of the metal. The coated
electrode as negative, is then placed in a dilute solution of sulfuric
acid and electrolyzed to charge with hydrogen. The bubbles should
come off evenly and the electrode should be evenly coated. The
deposit should adhere under a vigorous stream of water and the
electrodes should not be allowed to become dry. In use, electrodes
frequently become clogged, poisoned, or otherwise unfitted for further
use. The black should then be removed and the metal recoated. To
remove the deposit of black, the electrode is connected to the positive
pole of the battery and immersed in 1:1 hydrochloric acid which is
electrolyzed. Palladium is more easily removed by electrolysis than

Polarimetry, Saccharimetry, and the Sugars 289
is platinum. The latter, however, is easily removed if the platinum
electrode is plated with gold before the black is deposited.
(d) QUINHYDRONE ELECTRODE
The quinhydrone electrode (or half-cell), because of its simplicity
and ease of manipulation, has been widely used for pH measurement.
To make a measurement, the platinum or gold electrode is immersed
in the test solution and a small amount of quinhydrone, which is
sparingly soluble, is added and the potential is measured against a
Saturated calomel half-cell in liquid junction with the solution.
To calculate the pH of the solution from the observed potential,
Biilmann [5], whose investigations contributed largely to our knowl-
edge of the quinhydrone electrode, used the following equation:
– E-H Eq— Ec
O
where E is the observed potential, Eq is the potential of the quinhy-
drone-platinum electrode when (H+) = 1, and Ec is the potential of the
saturated calomel half-cell when (H+) = 1. The numerical values of
Eq and Ec, as given by Clark [3, p. 672), are, respectively, 0.6992v and
0.2458V, so that eq 87 becomes
0.4534 — E
pH=ºjigº, (88)
the sign of E being negative over most of the useful range of the
electrode. Tables or charts are furnished with quinhydrone pH
instruments, giving pH values corresponding to observed potentials
for several temperatures. s
For accurate results, the platinum or gold electrodes should be
cleaned after use, and with careful manipulation the limit of error is
about 0.01 pH. The quinhydrone electrode is inapplicable in the
presence of oxidizing and reducing substances and in alkaline solu-
tions with pH above 9.0. The arrangement of apparatus for pH
measurements is shown in figure 59 (A).
(e) GLASS ELECTRODE
Haber and Klemenziewicz [6] appear to have been the first to dem-
onstrate the usefulness of the glass electrode. Their electrode vessel
was made by blowing a thin bulb on the end of a glass tube and con-
tained an electrolyte in which dipped a platinum wire connected with
an electrometer. The bulb was immersed in the test solution and
the concentration chain was completed by means of a normal potas-
sium chloride—calomel half-cell. The apparatus was used for electro-
metric titration of acids and bases, and the authors considered that the
potential of the cell was determined in part by the concentration of
hydrogen ions. They used a soft glass in preference to others that
were tried, and directed that after the bulb was formed it was to be
steamed inside and out for an hour and kept in pure water until used.
Hughes [7], using apparatus similar to the above with the addition
of a potentiometer, showed that the potential varies quantitatively
with pH over a wide range of values and that the glass electrode may
290 Circular of the National Bureau of Standards
FIGURE 59.-A, Quinhydrome potentiometer (courtesy of Leeds & Northrup Co.);
B, pH electrometer (courtesy of Coleman Electric Co.).

Polarimetry, Saccharimetry, and the Sugars 291
be used in the presence of strong oxidizing or reducing agents when a
hydrogen electrode is useless. He also showed that the linear rela-
tionship of glass-electrode potential and pH is affected by strong
concentrations of certain salts. Kerridge [8] found the glass electrode
useful in the presence of substances of biological origin that poison a
hydrogen electrode. -
A study of the composition of glasses was made by MacInnes and
Dole [9], who consider as most suitable a glass composed of 22 percent
of sodium oxide, 6 percent of calcium oxide, and 72 percent of silica.
Glass of this composition, known as Corning 015, is made by
Corning Glass Works, Corning, N. Y. The same investigators [10]
produced membranes as thin as 0.025 mm by first blowing a bubble on
the end of a glass tube until red and blue interference colors appeared.
The end of a second tube, heated to dull redness, is placed against the
bubble and the film fused to it. These membranes are fragile but
have comparatively low resistance. Robertson [11] produced thin-
walled bulbs by drawing 10-mm tubing to a tapering point and form-
ing on this a small lump of glass by heating in a pointed flame. The
bulb was then blown to a volume of 8 or 10 ml. Thompson [12]
devised a metal-connected glass electrode of bulb or test-tube form by
silvering the outer surface. The silver film was protected by lightly
copperplating and the metal coating was then wired to a potentiom-
eter. The test solution was added to the vessel and the chain was
completed by means of a saturated calomel half-cell. No standard
electrolyte is used in actual pH measurement, but each electrode must
be calibrated before being used. This may be done with the help of
standard buffer solutions, and the cell constant is determined.
Accounts of the evolution of the glass electrode are given by Perley
[13], MacInnes and Longsworth [14], and by Clark [3], while theories
of the action of the electrode have been advanced by Haber and
Klemenziewicz [6], Horowitz [15], Michaelis [16], Dole [17], and Mac-
Innes and Belcher [18].
The Haber type of vessel, consisting of a thin bulb blown on the
end of a glass tube, is now commonly employed. Various electrolytes
have been used inside the electrode but a 0.1 N solution of hydro-
chloric acid (pH = 1.0) saturated with quinhydrone is generally favored
for routine measurements. The electrode tube is half-filled with the
solution, connection with the potentiometer being made with a short
length of platinum wire sealed in a narrow glass tube containing mer-
cury into which the potentiometer lead extends. The latter tube is
supported in the rubber stopper of the electrode vessel. The bulb
of the glass electrode is immersed in the test solution and a calomel
half-cell is used as a reference electrode. The concentration chain
may be represented thus:
Hg|HgCl, KCl (sat.) (). 1 N HCl
quinhydrone
*-*e
glass membrane
solution Pt.
The pH of an unknown solution is calculated from potential reading,
E, as with the quinhydrone electrode, as described under (d), p. 289.
That is, at 25°C.
H_0.6992–12:02458_04534 E.
pri- 0.05912 T 0.05912
292 Circular of the National Bureau of Standards
Tables giving pH values corresponding to potentiometer readings at
various temperatures are supplied with some instruments, whereas
others are calibrated to read directly in pH values.
Since the resistance of the glass electrode is high, a sensitive detect-
ing instrument must be used. Some workers prefer an electrometer,
but with improved electrodes, a lamp-and-scale galvanometer with a
sensitivity of 0.0005 ua per mm at 1 m is satisfactory, and an inexpen-
sive potentiometer of the usual type may be used (fig. 59, A). The
use of grounded metal supports for the electrodes prevents leakage
currents from reaching the galvanometer.
Various methods of thermionic amplification of the weak currents of
the glass electrode have been reported by Goode [19], Elder and Wright
[20], Partridge [21], Müller [22], DuBridge [23], Morton [24], Gilbert
and Cobb (25), and others. In figure 55 is shown a potentiometer-
electrometer in which the amplification is incorporated in the potenti-
ometer housing.
In some apparatus the entire assembly, consisting of potentiometer,
vacuum-tube amplifier, dry cells, galvanometer, pH electrodes, etc.,
is housed in a single portable unit. One of these units is illustrated in
figure 59 (B). With amplification, the employment of the glass
electrode in automatic pH apparatus becomes possible. Longsworth
and MacInnes [26] have described such a device for the automatic
control of the addition of alkali solution to a growing culture of acid-
forming bacteria. A pH recorder for sugar juices, in which a glass
electrode is employed, is described by Crites [27].
Electrodes made of the usual glass are considered inaccurate in the
presence of sodium salts at ranges above pH 9.5; however, a calibration
curve may be obtained for the range 9.6 to 12.5 which is said to be
reproducible within 0.1 pH. Very recently the use of a different
glass suitable for high alkaline ranges, has been reported [42].
(f) SILVER—SILVER CHLORIDE ELECTRODE
The silver-silver chloride half-cell, represented by Ag|AgCl, KCl(m),
where (m) refers to molar concentration, is analagous to the calomel
half-cell for which it has been substituted as a secondary reference
electrode, particularly in the study of reactions in chloride solutions.
The electrode consists of a coating of silver chloride, intimately
mixed with silver, on platinum or silver-plated platinum. The
platinum support, which may be in the form of a small rectangle of
foil or gauze or a wire coil, is sealed by means of a short lead of platinum
wire to a convenient length of glass tubing, as in the construction of
hydrogen electrodes. The silver-silver chloride coating may be
produced in various ways, either electrolytically [37], thermoelectro-
lytically [38], or thermally [39]. The last-named process is simple
and produces satisfactory electrodes. A coil of platinum wire is
sealed into a glass tube and covered with a paste composed of 7 parts
of silver oxide (precipitated and washed) and 1 part of silver chlorate
and heated to decomposition in an electric furnace. After coating
the electrodes, regardless of the process used, they are washed in many
changes of distilled water to remove contaminants, and finally washed
in the solution in which they are to be used. The period of washing
and aging to stability may extend to as much as 20 days.
Smith and Taylor [40] studied the reproducibility and stability
of silver chloride electrodes and found an average agreement of 0.02 mv,
Polarimetry, Saccharimetry, and the Sugars 293
among electrodes produced in the several ways referred to above.
They also found that even after proper aging, the potential is sensi-
tive to polarizing currents produced by as small as 0.1 to 0.2 mv.
These authors indicate that the difference in values reported for the
standard potential of silver chloride electrodes, quoted as varying
from 0.2221 to 0.2238 volt, may be due to insufficient aging time and
consequent lack of concentration equilibrium within the porous elec-
trode materials.
Values for the standard electrode potential of the silver-silver
chloride electrode as given by Harned and Ehlers [41] for the tem-
peratures 20°, 25°, and 30° C. are 0.2255, 0.2224, and 0.2191 volt,
respectively.
The utility of the silver chloride electrode has been realized in the
construction of glass electrodes where the inner member of the glass-
electrode assembly is a stabilized silver chloride electrode immersed
in a chloride solution, the assembly being sealed to prevent evapora-
tion. Polarization is said to be prevented by suitable electrical
construction.
3. AUTOMATIC RECORDING AND CONTROL OF pH
A scheme for the automatic recording of pH in lime-treated cane
juice was described by Balch and Paine [28], wherein a tungsten-
manganese sesquioxide electrode and a calomel half-cell in contact
with the flowing liquid were connected with an automatic recorder.
The quinhydrone electrode in special form also is used in certain
industrial solutions. Reference has already been made to the em-
ployment of the glass electrode for pH control on a relatively small
scale (26] and for recording the pH of sugar juices [27].
Electrodes of metallic antimony have been much used in industrial
control equipment. These have the advantage of being rugged and
not affected by flowing liquids. They may be set up in tanks and
other vessels and used in sugar factories for both automatic recording
and control of liming and gassing of beet juices. The electrode
assembly consists of the antimony electrode and a saturated calomel
electrode usually fitted into a chamber through which a sample of
the juice flows continuously, the potential established being propor-
tional to the pH of the juice. The electrodes are wired to a recording
and controlling device which contains a potentiometer circuit in
which the electrode potential is balanced automatically against an
adjustable standard potential. Deviation of the pH from the control
value unbalances the circuit, and the controller acting through a
relay actuates a motor-drive unit, which in turn operates a feeder
or valve to increase or decrease the flow of lime-milk or of gas.
The antimony electrode should be made from pure metal and
depends for its action upon the presence of very slightly soluble
Sb (OH)3 formed by the action of dissolved air or oxygen. The ex-
posed portion of the electrode is ground and polished at the start
and is wiped clean daily. The electrodes are calibrated for the solu-
tions in which they are to be used. The useful range of the antimony
electrode under proper conditions is said to be 2.0 to 12.0 pH in con-
tinuous operation, with a limit of error of 0.2 pH. Antimony elec-
trodes and their characteristics have been discussed by Perley
[13, 29, 30]. Reference has been made in section 2 (e), p. 292, to
the use of glass electrodes for pH control and recording.
294 Circular of the National Bureau of Standards
4. COLORIMETRIC METHODS
(a) WITH STANDARD BUFFER solutions
The standard buffer solutions used in the colorimetric determination
of hydrogen-ion concentration, according to Clark [3], are mixtures
of some acid or alkali with one of its salts, of such well-defined com-
position that they may be accurately reproduced, and with pH values
accurately defined by hydrogen electrode measurements. Several
such mixtures have been used, but the set of buffers devised by Clark
and Lubs [31], as described here, have proved satisfactory and are
conveniently prepared.
Stock solutions.—The following stock solutions are used in pre-
paring the standards: 0.2 M hydrochloric acid, 36.465 g of HCl
per liter, 0.2 M sodium hydroxide, 40.005 g of NaOH per liter.
0.2 M potassium chloride, 14.912 g of KCl per liter. 0.2 M acid po-
tassium phthalate, 40.836 g of KHCsPI.O, per liter, 0.2 M acid
potassium phosphate, 27.232 g of KH2PO, per liter. 0.2 M boric
acid-H 0.2 M potassium chloride, one liter of the solution to contain
12.4048 g of HaBO; and 14.912 g of KCI.
The ordinary chemically pure salts are not considered suitable for
making these stock solutions but are to be recrystallized three or
four times from water that has been redistilled from a Pyrex flask and
protected from absorbing CO2 by a soda-lime guard tube.
Although the salts, the stock solutions, and even the buffer mixtures,
especially prepared for pH determination, may now be purchased, the
preparation of the various stock solutions and the buffer mixtures to
cover the pH range 1.2 to 10.0 is briefly outlined here. Clark's
directions for recrystallizing potassium acid phthalate state that the
crystallization from the hot solution should be allowed to take place
slowly at a temperature not below 20°C, since there is deposited at
lower temperatures a more acid salt having the form of prismatic
needles instead of the six-sided orthorhombic plates of the salt,
KHCs H4O4. After the final crystallization the salt is dried at 110° to
115°C to constant weight.
Recrystallized potassium acid phosphate is dried at 110° to 115°C
and potassium chloride at 120° C. The boric acid is air-dried in thin
layers between filter paper, and the constancy of weight is established
by drying small samples in thin layers in a desiccator over CaCl2.
Preparation of 0.2 M sodium hydroxide.—To prepare the 0.2 M
sodium hydroxide solution, 100 g of high-grade stick soda in a Pyrex
Erlenmeyer flask is treated with 100 ml of distilled water which is
used for rinsing any adhering soda from the neck of the flask. After
solution and cooling, the flask is stoppered and allowed to stand until
carbonate has settled. It has been found convenient to filter this
strong solution by suction through purified asbestos (see Chapter XIX,
6 (a), p. 324) supported in a Jena No. 2 filter or in a Gooch crucible.
From this point on, the solution is protected from absorption of CO2
from the air by careful manipulation and by means of soda-lime guard
tubes. After a rough calculation, the clear filtrate is quickly diluted
to a solution somewhat more concentrated than 1.0 M. Of this solu-
tion 10 ml is withdrawn and titrated with an acid solution of known
strength. From this standardization, the dilution required to furnish
a 0.2 M solution is calculated. The dilution is made with the least
possible exposure and the solution is poured into a bottle thickly
Polarimetry, Saccharimetry, and the Sugars 295
coated with paraffin wax and to which a calibrated 50-ml burette and
soda-lime guard tubes have been attached. The solution is now care-
fully standardized. The purified acid potassium phthalate is recom-
mended by Clark for this operation. Portions of the salt of about 1.6 g.
each are carefully weighed on an analytical balance with standardized
weights and dissolved in beakers in about 20 ml of distilled water,
and 4 drops of phenolphthalein are added. A stream of air free of
CO2 is passed through the solution, which is titrated with the alkali
to a faint but distinct permanent pink. It is preferable to use a factor
with the solution rather than to attempt adjustment to an exact
0.2 M solution.
Preparation of 0.2 M hydrochloric acid solution.—A high-grade
hydrochloric acid solution is diluted to about 20 percent and distilled.
The distillate is diluted to approximately 0.2 M and standardized
with the sodium-hydroxide solution described above.
Preparation of the buffer mixtures.—The standard buffer mixtures
used in performing the actual pH tests are made, as already indicated,
by adding varying amounts of an acid or an alkali to a solution of its
salt. Although in routine sugar-factory work only a limited range of
buffer solutions may be required, the entire list is given here, since
the occasion frequently arises for tests in other ranges.
TABLE 35.-Clark and Lubs buffer mixtures, temperature 20° C.
50 ml of 0.2 M KCl–H X ml of 0.2 M HCl
Milliliters of 0.2 M HCl -- 46. 7 || 39.6 |32.95 |26. 42 |20.32 ||14.70 | 9.90 || 5.97 || 2.63 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
PH----------------------- 2, 2 2. 4 || 2.6 2.8 3.0 3.2 3.4 3, 6 3.8 ------|------|------
50 ml of 0.2 M KHC8H4O4+ X ml of NaOH
Milliliters of 0.2 M NaOH-] 0.4 || 3.70 || 7.50 |12. 15 |17.70 |23. 85 |29.95 |35.45 |39.85 |43. 00 |45. 45 || 47.00
Pti----------------------- 4. 0 || 4.2 4.4 4.6 4.8 5. 0 5.2 5.4 5. 6 5.8 6.0 6.2
50 ml of 0.2 M KH2PO4-H X ml of NaOH
Milliliters of 0.2 M NaOH. 3.72 || 5.70 | 8.60 |12. 60 |17.80 |23.65 29. 63 |35.00 |39. 50 |42.80 |45. 20 || 46.80
PH----------------------- 5, 8 || 6. 0 || 6. 2 | 6.4 || 6.6 6.8 || 7. 0 || 7. 2 || 7.4 || 7.6 || 7.8 8. ()
50 ml of 0.2 MH3BO3, KCl–H K ml of NaOH
Milliliters of 0.2 M NaOH | 2.61 || 3.97 5, 90 | 8.50 | 12.00 |16. 30 |21. 30 |26.70 |32.00 |36.85 |90.80 || 43.90
pH----------------------- ... 8 8, 0 8.2 8.4 8.6 8.8 9.0 9, 2 9.4 9.6 9.8 10. 0

In table 35 is shown, in the first horizontal line of figures, the
number of milliliters of 0.2 M acid or alkali that must be added to 50
ml of a given salt solution to produce 200 ml of standard buffer
mixture having the corresponding pH shown in the second line of
figures.
To prepare the solutions, 50 ml of the salt solution is pipetted into
a calibrated 200-ml glass-stoppered volumetric flask, and the required
amount of 0.2 M acid or alkali is run in from a burette. The solution
296 Circular of the National Bureau of Standards
is made up to 200 ml with double-distilled water, the flask is stoppered,
and the solution mixed.
For storage the standard buffer solutions are transferred to resistant
glass bottles labeled with the corresponding pH. The bottles con-
taining the most frequently used standards may be provided, for
convenience, with clean one-hole rubber stoppers, each carrying a
10-ml pipette.
Indicator solutions.—Indicators recommended for the colorimetric
determination of hydrogen-ion determination are listed in table 36
under the common names of the dyes. The list includes the indicators
originally selected by Clark and Lubs [32], while those marked with
an asterisk have been added as a result of the work of Cohen [33].
All are sulfonphthaleins with the exception of methyl red, an azo dye,
and cresol phthalein. Methyl red, although replaced in the revised
indicator list by chlor phenol red, is included in table 36 because it is
prescribed in the method of Gillespie, as described later. Opposite the
name of the indicator are given the molecular weight, the number of
milliliters of 0.01 N. sodium hydroxide needed to form the monobasic
salt of 0.1 g of dye, pK (= log 1/K, where K is the dissociation constant
of the indicator), useful pH range, and the colors of the acid and alkaline
forms of the dye.
TABLE 36.-Indicators of Clark and Lubs 1
| 2 3 4 5 6
- Milliliters
Molecu- *
* * * Of 0.01 N Color change, acid to
Name of indicator wºnt NaOH/0.1 g pK pH range alkaline
g of dye
Meta Cresol purple *_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 382 26.2 1.51 1.2 to 2.8 | Red to yellow,
Thymol blue----------- - - - - - - - - - - - 466 21.5 1.5 1.2 to 2.8 O.
Brom phenol blue- - - - - - - - - - - - - - - - - 669 14.9 3. 98 3.0 to 4.6 || Yellow to blue.
Brom cresol green *- - - - - - - - - - - - - - - - 698 14.3 4.67 3. 8 to 5.4 DO.
(Methyl red) ---------------------- 269 14.8 5. 10 4.4 to 6. 0 | Red to yellow.
Chlor phenol red” ----------------- 423 23. 6 5.98 4.8 to 6.4 || Yellow to red.
Brom phenol red *- - - - - - - - - - - - - - - - - 512 19.5 6. 16 5.3 to 6.8 DO.
Brom cresol purple---------------- 540 18. 5 6.3 4. 2 to 6.8 || Yellow to purple.
Brom thymol blue- - - - - - - - - - - - - - -. 624 16. 0 7. 0 6.0 to 7.6 || Yellow to blue.
Phenol red------------------------ 354 28, 2 7. 9 6.8 to 8.4 || Yellow to red.
Cresol red------------------------- 382 26. 2 8. 3 7.2 to 8.8 DO.
Meta Cresol purple” - - - - - - --------- 382 26, 2 8.32 7.4 to 9.0 || Yellow to purple.
Thymol blue---------------------- 466 21. 5 8.9 8.0 to 9.6 || Yellow to blue.
Cresol phthalein-------------------|----------|-------------. [9.4| 8. 2 to 9.8 || Colorless to red.
Mſ.": ºrmination of Hydrogen Ions, W. M. Clark, 3d ed. p. 94 (Williams & Wilkins Co., Baltimore,
., 1928).
*Added as result of later work by Cohen [33].
Stock solutions of the indicators are prepared by grinding 0.1 g of
the dry powder in an agate mortar with the corresponding volume of
0.01 N. sodium hydroxide given in column 3 of table 36. The alkali is
added little by little, and when solution is complete it is diluted to
250 ml with distilled water to give a 0.04-percent solution. Methyl
red (0.1 g) is dissolved in 125 ml. of neutral alcohol and diluted with
water to 250 ml.
Performing the tests.-Test tubes 15 mm in diameter and 120 mm
long are calibrated roughly for uniformity of bore by adding 10 ml of
water from a pipette and choosing those in which the water stands
Polarimetry, Saccharimetry, and the Sugars 297
at approximately the same level. These are cleaned and afterward
rinsed with distilled water, and drained. To separate tubes are
added 10 ml. of each standard buffer mixture to cover a chosen pH
range, and 5 drops of the appropriate 0.04-percent indicator solution.
Meade [34] recommends that the corks used for closing the tubes be
first boiled and thoroughly rinsed before inserting.
To another calibrated test tube is added 10 ml. of the solution to
be tested and 5 drops of the indicator. The matching of colors is best
done with the aid of a comparator, a simple form of which is the block
comparator described by Clark as having six deep holes of such size
as to accommodate neatly the test tubes, drilled parallel in pairs,
each pair being as close together as possible without breaking the wood.
Through the center line of each pair and at right angles to them are
drilled three smaller holes completely through the block so that light
may pass horizontally through the pairs of tubes when introduced.
The block is then painted a dull black inside and out. The back of
the illuminating holes is covered with a ground plate of colorless glass
to diffuse the light. The sample tube with indicator is placed in one
of the middle holes and backed by a tube of water. Standard tubes
containing the indicator are placed in the holes on either side of the
sample, and each is backed by a tube containing the sample without
the indicator, thus compensating for color and turbidity in the sample.
When the sample appears to fall midway between two standards that
differ by 0.2 pH unit, let us say, for example, between pH 7.2 and pH
7.4, then the value 7.3 may be taken as the pH of the sample.
There are other forms of comparators arranged for quick and con-
venient exchange of color standards, such as that of Meade and Baus
[35], which has a sliding rack carrying alternate tubes of color standard
and water, and of such length as to cover the entire pH range of the
indicator. A metal cover with suitably spaced apertures, and having
sockets for holding tubes of the sample and the sample plus indicator,
is provided. A white surface at 45° is placed behind the apertures
and illuminated from above with a Daylite Mazda bulb.
Care must be exercised in maintaining like volume of solutions and
of indicators and like thicknesses of light-transmitting layer. Alka-
line and neutral buffer solutions should be protected from absorbing
º dioxide and should not be allowed to come in contact with the
8,IlCIS.
(b) WITHOUT BUFFER SOLUTIONS.–GILLESPIE METHOD [36]
This method for the determination of hydrogen-ion concentration
without the use of buffer mixtures depends upon the ratio of the
number of drops of a given indicator present in a solution wholly
transformed into the alkaline form to the number existing wholly in
the acid form.
The indicators used are those of the original selection of Clark and
Lubs [32]. The stock solutions of the dyes are prepared, except in
the case of methyl red, by grinding 0.1-g portions with 1:1 equivalents
of alkali solution (1.5 equivalents in the case of cresol red) to give the
monosodium salt of the indicator acid. The equivalents of sodium
hydroxide may be obtained from table 36, column 3. When the
dye is in solution the volume is made up to 250 ml with water. Methyl
red is dissolved as explained under (a), p. 296.
In determining the data upon which table 37 is based, Gillespie
298 Circular of the National Bureau of Standards
made use of the Clark and Lubs buffer mixtures, as given in table 35,
which were checked electrometrically. The data were then smoothed
by use of the equation pH = k log (alkaline form)/(acid form), where
pH is the hydrogen-ion exponent, k is the apparent or total dissocia-
tion constant of the dye, and “alkaline form” and “acid form” desig-
nate, respectively, the concentrations of the indicator completely
transformed into the alkaline or acid form by excess of base or acid.
In table 37 the drop ratios are given in the first column, the first figure
of the ratio being the alkaline form and the second figure the acid
form of the dye. The pH values corresponding to these ratios are
found in the succeeding columns headed by the indicator used.
TABLE 37.—pH values corresponding to various drop ratios 1
Brom |Brom Brom - Y}) \r
Drop ratio phenol Mºyl CreSol thymol Pº Ol Cººl T º
blue purple blue
1:9-------------- 3. 1 4. 05 5.3 6. 15 6. 75 7. 15 7. 85
1.5.8.5------------ 3. 3 4.25 5. 5 6. 35 6.95 7.35 8. 05
2:8-------------- 3. 5 4.4 5. 7 6. 5 7, 1 7.5 8.2
3:7-------------- 3. 7 4, 6 5.9 6, 7 7.3 7.7 8.4
4:6-------------- 3.9 4.8 6. 1 6.9 7, 5 7. 9 8, 6
5:6-------------- 4. 1 5. 0 6.3 7. 1 7.7 8, 1 8. 8
6:4-------------- 4.3 5. 2 6. 5 7.3 7. 9 8. 3 9. 0
73-------------- 4. 5 5.4 6, 7 7. 5 8. 1 8.5 9. 2
8:2-------------- 4. 7 5, 6 6.9 7.7 8. 3 8.7 9.4
8.5:1.5------------ 4.8 5. 75 7. 0 7.85 8.45 8.85 9. 55
9:1-------------- 5. 0 5.95 7.2 8.05 8. 65 9. 05 9. 75
Produce acid col- 0.05 N ().05 N. 0.05 N. 0.05 N. 0.05 N 2% 2%
Or with. HCl, HCl, HCl, HCl, HCl, H2KPO4, H2KPO4,
1 ml 1 drop 1 drop 1 drop 1 drop 1 drop 1 drop
1 T. J. Gillespie, J. Am. Chem. Soc. 42, 744 (1920),
The following is the Gillespie procedure for the preparation and use
of the color standards: Test tubes, preferably without flanged tops,
15-mm bore and 150-mm length, selected for uniformity of bore as
already described under (a), are cleaned, rinsed, and drained. The
tubes may be held in pairs by means of a rubber band wound around
them in the form of a figure 8. It is convenient to use test-tube racks,
one for each indicator, each holding two rows of tubes, accommodating
one tube of each pair in front and one in back. For any desired indi-
cator a set of color standards is prepared by placing from 1 to 9 drops
in the back row of tubes, and 9 to 1 drops in the front row. A drop
of 0.05 N. sodium hydroxide is then added to each of the tubes in the
back row (2 drops in the case of thymol blue) to develop the alkaline
color. A 0.2-percent solution of stick soda is sufficiently accurate for
this solution. To each of the tubes in the front row is added the kind
and quantity of acid indicated at the bottom of each column in table
37. According to Clark, the 0.05 N. hydrochloric acid is prepared
with sufficient accuracy by diluting 1 ml of concentrated hydrochloric
acid (sp gr 1.19) to 290 ml. The volume is at once made up in all the
tubes to a constant height, corresponding to 5.5 ml with distilled water.
Each pair of tubes thus constitutes a colorimetric standard and is
to be labeled with the corresponding pH value given in table 37.
These dilute standards are not considered stable and daily renewal is
recommended.
Polarimetry, Saccharimetry, and the Sugars 299
A block comparator for matching solutions and standards, as shown
in Gillespie's article, is illustrated in figure 60. This is a modification
of the comparator described in section (a) in that there are three holes
in series instead of two to accommodate the extra tube. A third
series of vertical holes with a
third observation hole would
permit comparison with two
adjacent standards in the in-
dicator range.
To perform a test, 10 drops
of the desired indicator solu-
tion is added to a clean test
tube, and the test solution is
added in amount to match
the height of the standard
solutions in their tubes. The
sample tube with the indica-
tor is placed in the compara-
tor and is backed by two tubes
containing distilled water.
Pairs of the indicator tubes are
placed in two of the holes of
the other series and are backed
by a tube containing the
sample without the indicator.
For colorless test solutions, one
compensating tube may be
omitted from each series. The
pH value of the pair of stand-
ards most nearly matching the
sample containing the indi-
cator is taken as the pH value
of the sample. The same
precautions pointed out in the
º
|--—— -**----> --~~2:4---->
FIGURE 60.-Comparator for pH
measurement (after Gillespie).
previous section are to be observed in
regard to volume and concentration relations.
5. REFERENCES
1] F. J. Bates and Associates, Intern. Sugar J. 22, 654 (1922) (Abstract).
2] J. F. Brewster and W. G. Raines, Louisiana Planter 69, 167 (1923); Intern.
Sugar J. 25, 88 (1923).
[3] W. M. Clark, The Determination of Hydrogen Ions, 3d Ed. (The Williams
& Wilkins Co., Baltimore, Md., 1928).
[4] J. Reilly and W. N. Rae, Physico-Chemical Methods, 2d Ed. (D. Van Nos-
trand Co., Inc., New York, N. Y., 1932).
[5] E. Biilmann, Bul. soc. chim. 41, 276 (1927).
[6] F. Haber and Z. Klemenziewicz, Z. physik. Chem. 67, 385 (1909).
[7] W. S. Hughes, J. Am. Chem. Soc. 44, 2860 (1922).
[8] P. M. T. Kerridge, Biochem. J. 19, 611 (1925).
[9] D. A. MacInnes and M. Dole, Ind. Eng. Chem., Anal. Ed. 1, 57 (1929).
[10] D. A. MacInnes and M. Dole, J. Am. Chem. Soc. 52, 29 (1930).
[11] G. R. Robertson, Ind. Eng. Chem., Anal. Ed. 3, 5 (1931).
[12] M. R. Thompson, J. Research NBS 9, 833 (1933) RP511.
[13] G. A. Perley, Trans. Am. Inst. Chem. Eng. 29, 257 (1933).
[14] D. A. MacInnes and L. G. Longsworth, Trans. Electrochem. Soc. 71, 73
1937).
[15] K. Horowitz, Z. physik. Chem. 115, 424 (1925).
[16] L. Michaelis, Naturwissenschaften 14, 33 (1926).
[17] M. Dole, J. Am. Chem. Soc. 53,4260 (1931); 54, 2120, 3095 (1932).
[18] D. A. MacInnes and D. Belcher, J. Am. Chem. Soc. 53, 3315 (1931).






300 Circular of the National Bureau of Standards
[19] K. H. Goode, J. Am. Chem. Soc. 44, 26 (1922).
[20] L. W. Elder and W. H. Wright, Proc. Nat. Acad. Sci. 14, 936 (1928).
[21] H. M. Partridge, J. Am. Chem. Soc. 51, 2 (1929).
[22] R. Müller, Z. physik. Chem. 155, 451 (1931).
[23] A. DuBridge, Phys. Rev. 37, 392 (1931).
[24] C. Morton, J. Sci. Inst. 9, 289 (1932).
[25] E. C. Gilbert and A. Cobb, Ind. Eng. Chem., Anal. Ed. 5, 69 (1933).
(26] L. G. Longsworth and D. A. MacInnes, J. Bact. 29, 595 (1935); 31, 287
(1936); 32, 567 (1936).
27] N. Crites, Rep. Assn. Hawaiian Sugar Tech. Chem. Eng. Sect. 14, 41 (1935).
28] R. T. Balch and H. S. Paine, Planter Sugar Mfr. 75, 347 (1925).
[29] G. A. Perley, Ind. Eng. Chem., Anal. Ed. 11, 316 (1939).
30] G. A. Perley, Ind. Eng. Chem., Anal. Ed. 11, 319 (1939).
[31] W. M. Clark and H. A. Lubs, J. Biol. Chem. 25, 497 (1916).
[32] W. M. Clark and H. A. Lubs, J. Bact. 2, 1, 109, 191 (1917).
[33] B. Cohen, U. S. Pub. Health Service Rep. 41, 3051 (1927).
[34] G. L. Spencer and G. P. Meade, Handbook for Cane Sugar Manufacturers
and º Chemists, 7th Ed. (John Wiley & Sons, Inc., New York, N. Y.,
1929).
. P. Meade and R. Baus, Planter Sugar Mfr. 74, 509 (1925).
J. Gillespie, J. Am. Chem. Soc. 42, 742 (1920); Soil Sci. 9, 115 (1920).
. S. Brown, J. Am. Chem. Soc. 56, 646 (1934).
. S. Harned, J. Am. Chem. Soc. 51, 416 (1929).
. K. Rule and V. K. La Mer, J. Am. Chem. Soc. 58, 2339 (1938).
. R. Smith and J. K. Taylor, J. Research NBS 20, 837 (1938) RP1108.
[41] H. S. Harned and R. W. Ehlers, J. Am. Chem. Soc. 55, 652 (1933).
[42] L. R. º J. W. Hensley and T. H. Vaughn, Ind. Eng. Chem., 33, 723
(1941).
[3
;
i
XIX COLORIMETRY
1. INTRODUCTION
The maintenance and improvement of the quality and appearance
of sugar products leads naturally to the recognition of the importance
of colorimetry and of the need for adequate apparatus and methods
for the measurement of sugar color. The early literature on this
subject dealt with methods used in connection with the refining of
sugar with bone char; thus Wentzke [1] in 1860–61 published the
description of a “decolorimeter,” by means of which colors of solu-
tions were compared before and after char treatment. In these
articles Wentzke referred to the work done by Payen about 25 years
previously. In 1861 Stammer [2] published a description of the
instrument and method for sugar colorimetry that bears his name,
and which, little changed, is still in use.
In 1873 von Vierordt studied the measurement of color in diluted
molasses with a spectroscope, the entrance slit of which was divided
into upper and lower halves by independent jaws actuated by microm-
eter screws. To each screw was attached a drum which bore a gradu-
ated scale reading from 0 to 100. The opening and closing of the
slits thus served to vary the light intensity in a measurable manner
in either half of the field of view. The description of this apparatus
is contained in a reprint in the Bureau's possession. This was re-
printed in 1873 by Schmidt & Haensch, Berlin, from an article by
Vierordt, but the journal source is not cited. The table in the
reprint gives —log transmittancy corresponding to scale readings,
and layer thickness and dilution were taken into consideration in the
text, the latter on a volumetric basis. This approach to a spectro-
photometric method apparently received little attention from sugar
technologists until many years later.
Polarimetry, Saccharimetry, and the Sugars 301
In 1920 Bates and Associates [3] published a description of an
abridged spectrophotometer (to be described later) with which three
pure spectral lines of the mercury arc were used. This was the be-
ginning of a systematic investigation of color in sugar products at
the National Bureau of Standards. Spectral-transmission and
absorption curves of a large number of varied sugar products were
obtained over a greater part of the visible spectrum [4] and these
afforded a qualitative and quantitative measure of sugar color and
its characterization, and a way to the scientific classification of sugar
products according to color. These results served as a basis for
further investigation and demonstrated the possibility of using
abridged spectrophotometric methods and simplified apparatus
whereby sugar colorimetry, on a spectrophotometric basis, was made
quite as simple as by the Stammer method and without the objection-
able features of the latter.
In 1936 the International Commission for Uniform Methods of
Sugar Analysis [5] at its London meeting unanimously adopted the
resolution that “ ” * * spectrophotometry is to be considered the
basis of all colorimetric measurements in the sugar industry. It is
therefore recommended that absolute measurement be introduced as
far as possible into factory and commercial control, the measurements
to be performed with the monochromatic light of the mercury arc,
namely at the wave lengths 4358, 5461, and 5789 A, and that meas-
urements of —log tº at 5600 A be calculated from the measurements
at 5461 and 5780 A. It is to be understood that any country or
group of workers may use other wave lengths as desired.”
The adoption of the above resolution was prompted by practical,
as well as theoretical considerations. Not only is the measurement
of absorption more exact with monochromatic illumination than with
white light as used in former days, but it is much easier for the ob-
server, and there seems to be no other means of interrelating such
measurements over the whole gamut of sugar color. Spectrophoto-
metric equipment has been in use for several years in many laborator-
ies in the sugar industry for purposes of research and control and
this use is increasing, particularly in the field of simplified or abridged
spectrophotometry adaptable to routine observations.
2. COLOR NOMENCLATURE IN THE SUGAR INDUSTRY [4]
In the work at the National Bureau of Standards on color phe-
nomena in sugars, the recommendations contained in the various
reports of the Committee on Standards and Nomenclature and of the
Progress Committees of the Optical Society of America have been
adopted. Special care has been taken to conform to the recom-
mendations of the Committee on Spectrophotometry (6, 7} and of
the Committee on Colorimetry (Preliminary Draft) 1919, and subse-
quent reports of this latter committee published from time to time,
insofar as those recommendations adequately cover the ground. In
certain cases, however, it has been found necessary to coin new terms
and symbols. Where this has been necessary, the new symbols and
terms have been selected and defined in such a manner as to cover
the desired ground and at the same time be an extension of, and not
323414°–42 21
302 Circular of the National Bureau of Standards
in conflict with, the recommendations contained in the committees’
reports.
To one not thoroughly familiar with the subject, the elaborate
and extensive system, with its fine distinctions of meaning to be
hereinafter set forth, may appear somewhat pedantic and academic.
Not so, however, to him whose daily work is in this field, for he is
continually inconvenienced and annoyed by the circumlocution and
misunderstandings occasioned by lack of suitable terms and symbols
to express his ideas and findings cogently and without ambiguity.
It will be noted in the list of terms below that there are many that
are not explicitly used in the color work on sugar products. The
terms that are most used in experimental sugar work are relatively
few in number (T, t, — log t, — log t, c, b, \, Q, n, as defined below).
The others are necessarily given for the purpose of precisely defining
these terms and to bring out the small but important differences
between them and certain other similar terms.
In the case of homogeneous light passing through homogeneous
substances, such as a plane parallel polished plate of glass, we have
the following terms [6], all being functions of wave length:
E=radiant energy (of light source).
E = radiant energy incident upon the first surface.
E’=radiant energy reflected at the first surface.
E = radiant energy transmitted by the first surface.
Ey-radiant energy incident upon the second surface.
E’’=radiant energy reflected at the second surface.
Er – radiant energy transmitted by the second surface.
E = E1–E’.
T =#-transmission. It is the fraction of the incident light which is
E.
E – E/T
transmitted, and not lost either by reflection or absorption.
T =
#-transmittance ; that is, the transmission after cor-
recting for losses by reflection (8, 9]. The trans-
mittance per unit of thickness, which is called
transmissivity, t, may be calculated from the
transmittance, T, for any thickness, b, by means
of the relation
t=*VT=transmissivity, which is known as the Lambert law. No
exceptions to this law have ever been noted.
A=1 —T = absorbance.
For transparent solutions:
Tson. = transmission of a given cell containing the solution.
Tsoty = transmission of the same (or a duplicate) cell containing pure
solvent.
Toln. Tson. & $º e &
r=# =# =transmittancy; that is, the transmission after cor-
Solv. SO IV.
rection for reflection at the surfaces and for
absorption, if any, by the pure solvent.
Since the absorption of pure water is negligible for our purposes,
T has practically the same significance as T above. The symbols
T, t, A, referring to solutions, are distinguished from T, t, A, referring
to solids (or homogeneous substances), in handwriting and type-
writing by underscoring the former, and in printing by the use of
Polarimetry, Saccharimetry, and the Sugars 303
bold-face type as is recommended in the spectrophotometry report
(J. Opt. Soc. Am. and Review Sci. Instr., February 1925). Since in
all cases we compensate for losses by reflection by the use of a water
cell (or one containing a colorless sucrose solution) exactly similar to
the cell containing the solution to be measured, we have to do only
with the transmittancy, T, and not at all with the transmission, T,
or the transmittance, T.
t=specific transmissivity=transmittancy reduced to unit conditions
as regards thickness and concentration; t differs from t above in
that t takes into account concentration as well as thickness.
b=thickness (cm) of the absorbing solution.
c= concentration (grams of saccharine dry substance per 1 ml of
solution). c refers exclusively to the original colored dry sub-
stance, which consists of sucrose–H nonsugar-H coloring matters.
t=*VT or —log t=} —log T) = (Lambert–Beer law).”
—log tº is a measure of the coloring power—that is, intensity of
absorption—of the unknown amount of coloring materials associated
with 1 g of saccharine dry substance.
A=1 —T=absorbancy.
Since the transmissivity, t, and the absorption coefficient or expo-
nent are related according to the equation t=e^*, where i, the absorp-
tive exponent, depends upon the nature of the substance and the
wave length, it is evident that independent of the original use of the
minus sign before the log tº (log transmissivity) as a matter of con-
venience, -log tº is the absorptive index and has a definite physical
significance.
—log t- the specific absorptive index.”
X = wave length.
One color degree is the integrated (sum total) effect for the visible
spectrum of one absorption “unit” at each wave length. One unit
of coloring matter evokes a color sensation of one color degree and
X = 700
is measured by its integral (sum total) absorption ( > —log t)
X=440
* This law may or may not be valid for different types of coloring matters in solution under the conditions
obtaining in the sugar industry. Under these conditions it is valid at best only within rather narrow
confines as to concentration and transparency. However, it was found to be valid for several hundred
absorption spectra of technical sugar products ranging from white sugar to final molasses, but only upon
condition that stable transparency was produced in the solutions. This was accomplished by an improved
process of colorimetric clarification, which is described below. & & &
* -log tin the above committee reports was defined as specific transmissive index instead of absorptive
index. That specific absorptive index is the more appropriate name may be seen from the following demon-
stration. Using the symbolstabulated above for a homogeneous solid, suppose a beam of light passes through
a parallel-faced slab of thickness, b. The change (decrease) in energy, E, of the beam in passing through the
nfinitely thin layer, db, is given by the differential equation, —d E=iPºdb, where i is a coefficient proportional
to the absorption or absorbing power of the substance. It depends upon the nature of the substance and
the Wave length, but is constant for any given substance at any given wave length. It may be called the
absorption coefficient or exponent, as will appear later. tº e .
Separating the terms of this equation we have — (dE)/E=idb. Integrating between the limits b-0 to
b=b and E= E1 to E=E2 as above defined, we have
E2 b
–lossel -b]
Fl 0
Putting in these limits, -[loge E-loge Ei)=ib, or -loge E./E =ib. Since El El-T, -loge T =ib, or i=–1/b
log T--log t. Therefore, t-e-. Sincei in the differential equation is the quantity which defines absorp-
tion, º'- should be called the absorptive exponent and —log10t= iſ 2.3026= k should be called the absorp-
tive index.
304 Circular of the National Bureau of Standards
over the visible spectrum. The visual effect of this is represented by
X = 700
> WEt the luminosity curve of the transmitting layer of unit thick-
X=440
IlêSS. -
m= the number of units of coloring matter corresponding to n color
degrees and m absorption units.
77, - —log tº-560 (of sample) = —log ty–560 (of sample).
—log tix=560 (of standard) 0.00485
The sum total absorption of one unit of coloring matter,
= 700
,2,..., log ti, is defined as equivalent, colorimetrically, to the common
=44
absorption unit, -log ti, measured at X = 560, the wave length at
the optical center of gravity of its luminosity curve. The numerical
value of —log tº at X = 560=0.00485.
n is the number of units of coloring matter in 1 g of saccharine dry
substance.
3. VISUAL SPECTROPHOTOMETRIC APPARATUS
Reports on spectrophotometry and descriptions of spectropho-
tometers have been published by the Committee on Spectrophotometry
of the Optical Society of America [6], and later Gibson [9] described
Several spectrophotometers and discussed factors affecting the relia-
bility of spectrophotometric data. McNicholas [10] has described in
detail some of the equipment for routine spectral transmission and
reflection measurements used at the National Bureau of Standards.
Description and illustrations of various instruments are to be found
also in catalogs and advertising literature issued by the makers.
A spectrophotometer is a combination of devices consisting of (1)
a spectrometer for breaking up the light from the source into its
constituent wave lengths, (2) a photometer for Securing a two-part
photometric field with means for varying the brightness of one or
both parts in a measurable manner so that the eye is enabled to judge
equality of brightness, and (3) a source of light with auxiliary equip-
ment such as sample cells, supports, etc. With such apparatus, trans-
mission measurements may be made at numerous points over the
entire visible spectrum, and from the data curves may be plotted and
various ratios calculated which permit qualitative and quantitative
comparison of sugar color.
There are also simpler instruments not equipped with a dispersing
device but arranged by other means whereby certain wave lengths or
narrow spectral bands are made available for limited or abridged
spectrophotometry. Such instruments are well suited to routine work
in technical laboratories and are described in this section.
(a) BAUSCH & LOMB SPECTROPHOTOMETRIC EQUIPMENT
The Bausch & Lomb spectrophotometric equipment as used prin-
cipally for sugar colorimetry at the National Bureau of Standards is
described here to exemplify one type of polarization instrument. In
the drawings shown in figure 61 (Bausch & Lomb booklet [11])
the sections are, respectively, plan and side view of the complete
assembly for transmission measurements at fixed thickness, and a
Polarimetry, Saccharimetry, and the Sugars 305
large-scale view of the Martens-type photometer. The lettering of
the parts is uniform throughout. Light from the lamp, L, is diffused
by the double-ground glass, L2, which becomes the source of illumina-
tion. The beams are collimated and directed by the wedges, A, and
E— RHOMBOJD PRiSMS
F– COb-LECTIVE LENS
| G- wollasTON PRISM (Polarizer,
H– Gi-AN THOMPSON PRISM (ANALYzer)
!— Bi-PRISM COLLECTIVE ICEMENTED,
J– EYE LENS L1- 250 W. MAZDA LAMP
|
Ki- AUXILMARY LEN's Ln- GROUND GLASS i-AMP WiNDow
FP FP A- We DGES
Sº- COLLIMATOR SLIT •
M- COLLIMATOR SLIT MICROMETER SCREw B– CONDENSING lenses
On- COLLiMATOR OBJECTIVE C— SPECIMIEN TUBEs
Pi— COMPARISON PRISM
Pr- DisPERSING PRISM (PELLIN.skocA TYPE)
*::::= Rºss Os– TELESCOPE OBJECTive (Focusing)
º-r WD–WAVE LENGTH DRUM
R d FP— FOCUSING PINION
R— SHUTTER EYEPIECE HOLDER
SLIT ADJUSTMENT
SLIT wºoth scALE ADJUSTMENT
sirr wºoth scals.
EYEPIECE
SCALE READeº
PłłOTOMETER SCALE
RH()MBOID PRISMS
COLLECTIVE LENS
WOLLASTON PRISM (POLARIZER)
GLAN THOMPSON PRISM (ANALYZER)
BI-PRISM COLLECTIVE (CEMENTED,
EYE LENS
EYE POINT DIAPHRAGM
SCALE READER
PHOTOMETER SCA F.
FIGURE 61.-Bausch & Lomb spectrophotometric outfit for transmission measurements.
Above, plan and side view of complete assembly; below, large-scale view of photometer.
lenses, B, through the solution and solvent cells, C, and are focused
by the second pair of lenses, B, upon the rhombs, E, at the aperture
of the photometer whereby they are directed through lens, F, into the
polarizer, G, a Wollaston double-image prism. The two beams, one
from each aperture, transmitted by the Wollaston prism are polarized






306 Circular of the National Bureau of Standards
in mutually perpendicular planes and enter the analyzer, H, a Glan
Thompson prism fixed in a rotatable sleeve to which is attached the
graduated circle, U. By rotation of the analyzer the intensities of the
two beams may be equalized and the angle of rotation noted on the
circular scale. The light of the two beams transmitted by the analyzer
is focused upon the biprism at I, whereby it is directed along the axis
of the photometer. On leaving the analyzer, the light of these two
beams is linearly polarized in the same plane, so that the action of
the biprism on each beam is the same.
At the eyepiece diaphragm, K, may be seen a circular field with
horizontal dividing line formed by the edge of the biprism which is
brought into focus by means of lens, J. By rotation of the analyzer
through 360°, it is seen that complete extinction of each half of the
field occurs twice at points 90° apart. Midway between each pair of
extinctions lies a point at which the two halves match. This is the
Zero point. When the instrument is in proper adjustment and both
apertures are equally illuminated, the zero point falls at 45° and the
photometer becomes direct reading.” One quadrant of the circle is
calibrated to read directly in terms of T, a second quadrant in terms
of -log percent, and the remainder of the circle in degrees from 0°
to 180° C.
The eyepiece diaphragm at K is replaced by a short-focus lens that
images the photometric field upon the adjustable vertical collimator
slit of the spectrometer at S in the focal plane of the collimator lens,
O1. Spectrally dispersed by the prism, P., the light enters the tele-
scope system through the objective, O2, and is observed through the
eyepiece lens at d. Within the eyepiece holder, R, is a shutter or eye-
piece slit, the width of which is adjustable by lever b, thus defining
the length of the spectral band observed and controlling the spectral
purity. The eyepiece slit is movable horizontally across the axis of
the telescope and along the length of the spectrum by turning screw
head a, which provides a means of wavelength calibration. The
dispersing prism is mounted on a turntable actuated by a micrometer
screw to which the wavelength drum, WD, is fixed. The latter is
graduated in units of 1 mp, from 400 to 800 mp. The rotation of the
prism table brings any desired part of the spectrum upon the central
part of the field as defined by the ocular slit and as indicated on the
wavelength drum. At the eyepiece lens of the spectrometer the
observer sees a rectangular field composed of two juxtaposed spectra
with horizontal dividing line; in other words, a portion of the spectral
image of the two-part photometric field.
The wave-length scale of the spectrometer may be calibrated by
means of mercury or helium lamps, or by wave lengths from other
Sources. The photometer scale may be checked by means of rotating
sectors of fixed opening (see following section) [10], which may be
accurately calibrated mechanically, or by means of filters of accurately
known transmission [9]. Measurements on a solution at different
thicknesses may also assist in detecting errors, the negative loga-
rithm of the transmittancy being accurately proportional to the
thickness [9].
15 In earlier designs of the Martens photometer, the biprism was cemented to the front face of the Wollaston
prism. The light of the transmitted beams, being polarized in planes mutually perpendicular, was affected
unequally by the inclined faces of the biprism, and the amount of light transmitted by the two halves of the
biprism was not the same. The zero point, therefore, did not fall at exactly 45°, which precluded the use of
direct reading.
Polarimetry, Saccharimetry, and the Sugars 307
A pair of absorption cells to contain solution and solvent, respec-
tively, are shown at C. The diameter of these should be such that
light does not reach the inside cylindrical surfaces and become re-
flected into the photometer. This, however, may be prevented by
using proper diaphragms. The focusing lenses at B, nearest the
photometer, may be omitted in many cases or may be replaced with a
diaphragm, thus allowing longer absorption cells to be used. To
permit measurements over a wide range of transmission and long spec-
tral range, an assortment of matched pairs of cells should be available
in thicknesses between end plates of 0.5, 1.0, 2.0, 5.0, 10.0, and 20.0
cm. The 0.5, 1.0, and 2.0-cm sizes are available in the usual U-
shaped form with glass separators, while the larger sizes are in the
form of glass cylinders fitted with screw caps in the manner of sac-
charimeter tubes and having stoppered side openings. Cells with
fused-on glass end plates may now be purchased.
The interchange method is used in measuring the transmission of a
Solution relative to that of the solvent at any wave length. After a
Series of measurements has been recorded, the position of the cells
relative to each other (and to the respective apertures of the photo-
meter) is reversed and a second series of an equal number of readings
is taken. If either of the direct-reading scales has been used, the
arithmetic mean of all the readings is taken as T, or —log TX. If the
degree scale is used with the zero point falling at or near 45°, the arith-
metic mean of each series of readings in angular degrees is taken and
the transmittancy is found by
T=cot 91X tan 6, (89)
where 01 and 02 are the observed angles of match, respectively, with
the sample in positions 1 and 2.
By the use of an illuminated white-lined sphere substituted for L,
the apparatus may be used for spectral-reflection measurements.
The reflection standard and the sample are in a rotary specimen
holder in a vertical position at the side of the sphere opposite the
apertures of the photometer and are illuminated by the white inner
surface of the sphere which contains two 500-watt Mazda lamps.
Soft sugars may be pressed into a suitable container in a manner to
present a smooth, flat surface, the reflectance of which may be meas-
ured. For dry granular sugars a cover must be used to retain the
sample because of the vertical mounting. According to Judd and
Gibson [56], an error of as much as 10 percent may result from the
use of the cover glass.
(b) GAERTNER POLARIZING SPECTROPHOTOMETER
This apparatus, figure 62, also consists of a spectrometer, polarizing
photometer, illuminating device, and equipment for mounting the
samples [12].
The white-lined diffusing sphere at the right contains four 200-watt
incandescent lamps and serves for illumination. For transmission
measurements, a diffusing white surface is placed at the back of the
sphere and serves as the light source (upper drawing). This may be
replaced by an opal or ground glass, if desired, permitting illumination
by a mercury arc or other source. Light from the diffusing surface is
collimated by a lens and then divided by a pair of rhombs into two
308 Circular of the National Bureau of Standards
beams that pass through the tubes containing the solution and solvent.
The beams are then directed by rhombs and lenses into the Martens-
type photometer. -
For reflectance measurements (lower part of diagram) the first pair
of rhombs is removed, the two beams coming directly from the surfaces
of sample and reference standard. The sample and standard are
carried on a holder and may be interchanged in vertical position.
This position is not suitable for dry, granular sugars.
The photometric field is circular with horizontal dividing line, being
projected through the entrance slit to a position in the collimator
objective where it is viewed from the ocular slit without eye lens.
Transmission and reflectance are computed by the formulas used with
the instrument described under (a), p. 307. The instrument also
ASAEAE-3/X&ZºZAZYZTACGP. 7&2/X5/Ø/Y/ZZ25C/CA///y/.5
... **. - la---==========E=E== == −–H
'º- ,-- E=====-4---------E w
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O427/C43Z A-249/AKS AO42 AeAſAZAC//O/Y / 7: A SO/47A/7ZºzyżJ’
FIGURE 62.-Gaertner polarizing spectrophotometer.
may be made direct reading if the angle of match (100 point) can be
secured at exactly 45°.
(c) KöNIGS-MARTENS SPECTROPHOTOMETER WITH AUXILIARY
EQUIPMENT DESIGNED AT THE NATIONAL BUREAU OF STANDARDS
The following description of this apparatus is a part of that given
by Gibson [9], and figure 63 is a reproduction of figure 3 of an article
by McNicholas [10].
Light entering the collimator slits, A and B, forms beams 1 and 2. These beams
follow the usual course through the collimator lens, dispersing prism, and telescope
objective. Cemented to the latter lens is a combination of Wollaston prism,
wedge, and biprism. The purpose of the wedges in the collimator and telescope
is to prevent passage to the eye of certain multiply reflected rays from the optical
surfaces.
Looking through the ocular slit one sees the surface of the biprism uniformly
illuminated by a mixture of light of wave-length range determined by the widths
of the collimator and Ocular slits, the mean wave length corresponding to the
position of the Ocular slit in the spectrum. The biprism edge forms a vertical
dividing line in this photometric field which is circular and the lights in the two
halves of the field are plane-polarized in directions perpendicular to each other.

Polarimetry, Saccharimetry, and the Sugars 309
By turning the nicol between the eye and the ocular slit, the two parts of the field
may be matched in brightness.
For spectral-transmission measurements three different illuminants are used,
Viz, the mercury arc, the helium lamp, and the incandescent lamp. Only the
latter is shown in the diagram. Each of the three illuminants is mounted in a
Small enclosure, the inside surface of which is coated with MgO. In each case the
light used for the transmission measurements is taken from the diffusing rear
surface of the enclosure; this is collimated by the combination lenses (3) and
enters the collimator slits, A and B, as shown.
The drum in which the analyzing nicol is mounted is graduated only in degrees
reading from 0° to 360°. Since the angle of match does not fall exactly at 45°,
the scale is not direct reading. The method of interchanging the sample in the
two beams is used, and T is computed by formula:
T = cot 61 Xtan 62.
The mercury and helium illuminants afford ready means of checking the wave-
length calibration of the spectrophotometer; they also enable measurements of
$KOING-MARTENS
FIGURE 63.-Königs-Martens spectrophotometer.
transmission to be made at certain wave lengths free from slit-width or wave-
length error. - -
The rotating sector, shown in the diagram between the collimator slit and the
transmission sample, serves two purposes: (1) It enables a direct check to be
made on the reliability of the photometric scale. A number of sectors are avail-
able to give transmissions of approximately 0.01 to 0.80. These apertures are
accurately determined mechanically. Any desired sector may be placed in
position, rotated rapidly enough to eliminate flicker, and its transmission deter-
mined photometrically in the same manner as for the transmission sample.
(2) To measure low transmissions, the 0.10 or 0.01 sector is placed in the blank
beam and the transmission of the sample is measured relative to that of the sector.
This brings the angles of match away from the extinction points into a more suit-
able region of the scale and greatly extends the range of the instrument for low
transmission measurements.
For spectral reflectance measurements, the sample and reference white standard
are placed, as shown, at the base of a hemisphere whose interior surface is coated
with MgO and studded with 156 small lamps so that, in effect, the sample and
standard are in completely diffused illumination. The light reflected at right
angles from the sample and standard, respectively, forms beams 1 and 2 and
enters the spectrophotometer via right-angled prism 4 and lenses 1 and 2. Sample
and standard may be reversed in position by the observer and the apparent


310 Circular of the National Bureau of Standards
reflectance of the sample, Rs, relative to that of the standard, Ro, is given by the
relation, analogous to formula 89,
#=cot 61 tan 62.
(d) KEUFFEL & ESSER COLOR ANALYZER
This spectrophotometer is designed for both transmission and re-
flectance measurements and the arrangement of parts and the light
paths are shown in figure 64, as given in the article by Keuffel [13].
The white-lined sphere is illuminated by two 400-watt lamps. For
transmission measurements, two blocks of magnesium carbonate are
placed at 6 and 7. The light diffusely reflected from these surfaces is
incident upon the cells at 8, containing solution in the upper one and
FIGURE 64.—Keuffel & Esser color analyzer.
Upper, plan; lower, side view. 1, White-lined sphere; 4, wave-length scale; 5, photometer scale; 6, magnesia
block; 7, magnesia block or solid sample; 8, cells for solution and solvent; 9, two-part field; 12, lamps; 14,
revolving sectors; 15, motor; 17, entrance slit; 18, collimating lens; 19, dispersing prism; 20, lens; and 21,
eyepiece diaphragm.
solvent in the lower. The photometric device consists of two sec-
tored disks, one larger in diameter than the other, encased in a housing,
14, with windows through which the light passes to the slit. These
disks rotate around the same axis in the same direction and are driven
by a motor at sufficient speed to eliminate flicker. The smaller
sector is movable concentrically across the openings of the larger while
rotating, by means of the knurled head to which the photometer scale,
5, is attached. Near its edge the larger sector, intercepting the upper
beam in which the solution is placed, transmits a constant amount of
light which enters the upper half of the collimator slit of the spectrom-
eter. The combined opening of the two sectors below the edge of
the smaller intercepts the lower beam transmitted by the solvent, the
amount of light entering the lower half of the slit being variable from
0 to 110 percent.

Polarimetry, Saccharimetry, and the Sugars 311
The spectrometer is similar to that already described in (a) and (b).
Wave-length selection is accomplished by turning the knob attached
to the wave-length scale, 4. The emergent spectra from the disper-
sion prism are directed along the telescope tube and are viewed through
the ocular slit, 21, where a circular 2-part field with horizontal dividing
line is seen. The two halves of the field may be matched by turning
the knurled head carrying the photometer scale and the transmittancy
is read directly. The lever at 13 operates an adjustment which lowers
the sectors and doubles the amount of light transmitted. This
arrangement is used for low transmissions, the sectors being so con-
structed that the scale then reads four times the actual value.
4. APPARATUS FOR ABRIDGED SPECTROPHOTOMETRY
(a) IVES TINT PHOTOMETER [14]
This instrument, which has been widely used in the sugar industry,
is illustrated in figure 65. Light from the Daylite lamp located at
Figure 65.-Ives tint photometer.
Courtesy of Palo-Meyer.
the back near the top is diffusely reflected upward by the block of
MgCOs that rests on an adjustable support and is again reflected by
the inclined mirror into the two entrance apertures of the instrument.
The width of one aperture is fixed, while the width of the other may
be varied measurably by a lever shown at the top of the instrument.
The index on this lever traverses a scale graduated to read from 0 to
100 in equal divisions corresponding to the percentage of opening.
At a reading of 100 the two halves of the eyepiece field should match.
Three color filters (red, green, and blue) supplied with the instrument
permit measurements to be made in the three corresponding spectral
regions. A fourth filter, transmitting a rather broad band of yellow
green, is provided for the use of sugar technologists. Between the
mirror and the apertures, provision is made for placing absorption
cells. To make a measurement, the cell containing solution is placed
over the fixed aperture, while the cell with solvent is placed

312 Circular of the National Bureau of Standards
over the variable aperture. With a chosen color filter in place, an
intensity match is obtained by means of the lever, and the scale
reading is noted.
A mercury-arc light source with appropriate spectral filters, as
described under 5 (e) p. 324, may be used to advantage with the
Ives Tintometer, or a Brewster or Gibson filter may be used for direct
measurement at \560 mp. (see 4, (c), p. 314).
Meade and Harris [15] evolved a method for translating the scale
readings of the Ives Tintometer into sugar color units. They obtained
transmittancy readings with different concentrations of a certain raw
sugar in water solution and found that any set of readings in a series
is related according to a power function such that where
y=any scale reading,
K= the scale reading for 1 unit of material, and
ac- the number of units of material required to give a scale
reading of y, •
then
J– K*, or log y=a log K, from which *Tog k.
To avoid repeating the calculation for each reading, Meade and Harris
adopted the reading 99 as a standard and calculated a table by means
of the last expression, wherein is given for each scale reading, y, the
ºding number of color units, ar, of the hypothetical solution
(K=99).
(b) MODIFIED STAMMER COLORIMETER
Bates [16] and associates [3] first used the mercury arc as a light
Source for sugar colorimetry in connection with a modified Stammer
colorimeter. The arrangement of the apparatus is shown in figure 66.
A sector is mounted on a shaft which rests on bearings in such position
that, when rotating, the blades of the sector alternately intercept and
transmit the beam of light entering the open tube of the colorimeter.
When the speed of rotation is high enough to eliminate flicker, the
light transmitted is directly proportional to the aperture of the sector,
which may be determined mechanically. Two such sectors are used,
One transmitting 80 and the other 46 percent, and are easily inter-
changeable on the shaft. The shaft is provided with a pulley con-
nected to the small driving motor by a belt.
The column of solution in the closed colorimeter tube is varied in
length by means of the plunger until the intensities of the two halves
of the field match. The height of the liquid column, in centimeters,
is read on the scale. The transmittancy, T, is then equal to the
known T of the sector, from which —log tº is calculated by
—log t-1/cb (–log T). -
The reflection losses caused by the end plates in the solution tube
and plunger are compensated by introducing two similar plates over
the upper end of the open tube.
Spectral filters for isolating the yellow, green, and blue-violet
mercury lines are described under 5 (e), p. 324.
(c) DUBOSCQ COLORIMETER
A standard type of Duboscq colorimeter has been adapted by
Brewster [17] to purposes of abridged spectrophotometry suitable for
Polarimetry, Saccharimetry, and the Sugars 313
sugar factory laboratories. The light source may be either a mercury
arc with the appropriate filters or an incandescent tungsten lamp with
which a special 560-mu filter is used. Glass plates calibrated for
transmission at the various wave lengths are used as standards. The
apparatus, figure 67, consists of a Bausch & Lomb Duboscq colori-
FIGURE 66–Stammer colorimeter modified for abridged spectrophotometry.
meter with 10-cm cups, to the vertical column of which a shelf with
a heavy bracket is fastened with screws to leave a clearance of 1 cm
when the cups are in their lowest position. A carrier for the standard
plates with a 25-mm center orifice, and with the ends cut as shown,
slides between guides on the shelf and has a slot that engages in a

314 Circular of the National Bureau of Standards
metal stop at the center of the shelf to center properly the orifice
under either cup. A 60° prism enclosed in the triangular housing
of the eyepiece telescope permits observation with the head in a
natural, unstrained position. The adjustable mirror at the bottom
of the colorimeter is silvered glass with the outer surface ground to
diffuse the reflected light.
Spectral filters for obtaining light from ordinary tungsten illumina-
tion at wave length 560 mp or close thereto have been devised by
Brewster [18] and by Gibson [19]. These permit very satisfactory
measurement of transmittancy at this wave length. The composition
of these filters is given in table 38.
TABLE 38.-Spectral filters for 560 mp.
Brewster Gibson
Material Thickness Designation of glass Tº
- 77,777.
Wratten filter 21---------------- - - - - - - - - 1 layer . . . . . . . . . Corning 351 . . . . . . . . . . -- - - - - - - - - || 4. 55
Wratten filter 61 - - - - - - - - - - - - - - - - - - - - - - - . . . . do - - - - - - . . . Corning didymium 512 - - - - - - - - - -. 5. 82
Corning didymium glass 512- - - - - - - ----- 6.5 mm . . . . . . . . . Jena V G–3 - - - - - . . - - - - - - - - - - - - - 1.99
Colorless glass---------------- - - - - - - - - - - l to 2 mm - - - - - - - Jena B G-18. -- - - - - - - - - ------------ 1.94
The components are sealed together with Canada balsam and may
be bound with black tape or mounted in metal. The filters may be
cut to such diameter as to be mounted in the telescope tube of the
instrument or may be used over the eyepiece. In the Brewster filter
the gelatine sheets are sealed between the glass components. In the
Gibson filter the Jena glasses are sealed between the Corning
components. -
In the Brewster filter the spectral centroid of the transmitted light
for incandescent tungsten illumination at 2,848° K was computed to
be 558.8 mp. For the original Gibson filter and certain replicas
made at this Bureau, the optical centroid, under the same conditions
as above, was found to be located at 560.0 mp.”
A second filter consisting of a blue glass, Jena BG-12, thickness
3.42 mp, is used by Brewster for the special case of very pale sugar
solutions, such as those of high-grade refinery products. The optical
centroid of this filter was computed for 2,848°K as being at 459.9 mg.”
The photometric standards are plane parallel plates of polished
glass, the color of which is known as “carbon amber.” This glass is
obtainable in shades varying from brown to palest straw. These
are to be calibrated in terms of transmission, T, at wave length 560 mp.
This calibration is best obtained by sending the plates to the National
Bureau of Standards with a request for calibration, as above specified.
The transmission value may be controlled by the shade and thick-
ness of the glass, and it is advisable to have plates of three values,
16 At the time this was written there was difficulty in obtaining exact duplication in the two Jena glasses
used in the Gibson filter. However, it is doubtful that a slight shift of the optical centroid on either side
of A560 by 1 or 2 mp would greatly affect the results in sugar colorimetry. Attempts to duplicate this filter
by substituting glasses with transmission properties too greatly different from those specified by Gibson
would likely result in an inferior filter.
17 In order to measure transmittancy in extremely pale sugar solutions at 560 mp, excessive layer thickness
is required beyond the 10 cm available in the standard type of Duboscq colorimeter. Employment of the
460-mg filter is therefore a compromise between having an instrument constructed with much longer cells or
choosing a wave length at which the light absorption is greater.
Polarimetry, Saccharimetry, and the Sugars 315
one each with TA-sºo me about 50, 70, and 80, respectively. This
makes for flexibility of the method, permitting measurements over a
sufficient range of shades. The glass is customarily supplied in the
form of 2-inch polished squares, but other shapes and sizes may be
specified to conform to the construction of the instrument. For meas-
urements with pale solutions and the 460-mu filter, a plate consisting
of colorless optical glass calibrated in terms of T at 460 mu is used.
To measure the transmittancy of a solution a portion is added to
each colorimeter cup, a standard is placed in the carrier and centered
under one of the cups, which is adjusted in height to a scale reading of
1 cm. With the spectral filter
in place, the observer adjusts the -
height of the opposite cup to a - º
photometric match and records
the scale reading. Three to five
such settings are made, and the
standard is shifted by sliding the
carrier and centering the stand-
ard under the opposite cup,
which is then adjusted to the
1-cm scale reading as above,
and a second series of the same
number of readings is recorded.
This substitution method of com-
parison is the usual one employed
with direct-reading spectropho-
tometers and serves to compen-
sate for any error of zero setting.
The readings in centimeters
are added, and the sum is divided
by the total number of readings
to give the mean. The blank
setting (1 cm) is deducted, and
the remainder represents that
thickness, b, of the solution
whose transmittancy, T, equals
the calibrated transmission of
the standard at the specified
wavelength. Assuming that the
dry substance concentration, c, " "
in grams per milliliter, as gi - -
g p : given Figure, 67-Duboscq colorimeter with ac-
in table 114, (corresponding to - -
- - cessories for abridged spectrophotometry.
the refractometric Brix of the f ged sp p ſ
solution) is already known, the final value, –log t, is found by sub-
stituting the values of b, c, and —log T (table 129) in the Lambert-
Beer equation, -log t-1/cb (–log T).
(d) ZEISS-PULFRICH PHOTOMETER
This instrument, with accessories and methods of manipulation for
yarious photometric purposes, was first described by Pulfrich [20].
The diagram in figure 68 illustrates the photometer (accessories not
shown). The optics will be understood from a glance at the drawing.

316 Circular of the National Bureau of Standards
It consists in principle of two parallel telescopes having a common
eyepiece, and is enclosed in a cast housing. The device for measurably
varying the intensity of the light is shown in the drawing.
The two diaphragm leaves, with 90° openings, are movable toward
or away from each other by equal amounts by means of the microm-
eter screws. These screws are turned by means of the drum upon
which scales are engraved. When the drum is set at the scale-reading
100, the diaphragm is full open; and at 0 (a complete drum revolution)
it is completely closed. One scale reads directly in values of trans-
mission and the other in extinction (-log T). The graduations are
read from a common index line engraved on a small glass plate. Since
both telescopes are provided with photometric devices, the substitu-
tion method may be used. The instru-
ment may be mounted either in a vertical
or a horizontal position. Supports, ab-
sorption cells, and illuminating lamps with
appropriate housing, including a mercury-
vapor lamp, are available. The Zeiss
pamphlet [21] describes these in detail.
Four different kinds of color filters
designated S, K, L, and Hg, respectively,
are supplied for use with the photometer,
the Hg series being used with the mercury
arc, and the others with incandescent
tungsten or other white-light source.
There are nine filters in the S series
characterized by high optical density and
narrowest transmitted spectral band of
the three series. The seven filters of the
K series transmit relatively wider bands
and more light than the S series, while the
three L filters have high transmission and
e . . are used for faint luminosities. Landt
º; t º:º [22] states that the Pulfrich photometer
pho º º º º ... with a mercury arc as light, source, and
*...*.*.*.*.*.*.*.*.* with the appropriate spectral filters, may
º Prisms. P. biprism: oº be recommended, for purposes of color
g measurement in the sugar industry. No
doubt one of the 560-mg filters described under (c) p. 314 could be
used to advantage with this instrument.
5. PHOTOELECTRIC PHOTOMETERS
Photoelectric cells of various kinds have become available at moder-
ate cost within the past few years, and their use in the construction of
colorimetric apparatus has become widespread. This is true particu-
larly in the field of analytical chemistry, a review of which, with an
extensive bibliography, has been published by Müller [23]. The ad-
vantages and limitations of photoelectric cells in colorimetry have been
discussed by Gibson [24].
Among the advantages of photoelectric over visual methods may be
named: Greater objectivity of measurement; relief from eyestrain and
fatigue; and, under good conditions, greater speed. The precision and

Polarimetry, Saccharimetry, and the Sugars 317
reliability of results depend upon the design and construction of the
apparatus. Specific literature references to the measurement of
sugar color with certain photoelectric instruments are given in ref-
erences [25 to 33] at the end of the present chapter. Some of the
instruments there cited had been designed primarily for sugar color-
imetry, while others evidently were intended for purposes of analytical
chemistry. For the measurement of transmittancy of sugar solutions
over a great range, as, for example, in comparing the decolorizing
efficiency of carbons, a flexibility is demanded that is not usually
present in analytical apparatus. This may be attained by providing
for (1) the accommodation of a variety of thicknesses of absorbing
layer up to 20 cm and (2) for the employment of monochromatic light.
The second of these considerations is more important in photoelectric
than in visual photom-
etry over wide trans-
mission ranges, because
when a photocell is il-
luminated by a spectral
band that is too wide,
it responds to all the
impinging light, where-
as the eye, being unable
to integrate over a
broad spectral band, re-
sponds to the effective
wave length.
Discussion of the nu-
merous optical and elec-
trical arrangements that
have been employed in
the construction of pho-
toelectric photometers
cannot be attempted Figure 69.—Objective sugar colorimeter of Sandera.
here. This is to be
found in the references cited. The instruments described in the fol-
lowing pages have been used particularly for the measurement of sugar
color and will serve to illustrate some principles of design and con-
struction.
(a) SANDERA. OBJECTIVE SUGAR COLORIMETER [25]
The apparatus devised by Sandera is illustrated in figure 69. Light
from the incandescent filament inclosed at 0 passes through the
diaphragm and lens at e to form a practically parallel beam, which is
transmitted by the solvent in cell, a, or solution in cell, b. These cells
rest upon a movable carrier, whereby the cells may be interchanged
as desired. The transmitted beam enters the window of the photo-
tube, A (a potassium cell) and strikes the sensitive surface, K. The
voltage is supplied from a battery. The photoelectric current is
amplified by means of the vacuum tube, while the millivoltmeter in the
plate circuit is the indicating instrument. By means of the variable
resistance, R3, the sensitivity of the millivoltmeter may be varied so
that dark- and light-colored solutions may be measured equally well.
323414°–42—22 r

3.18 Circular of the National Bureau of Standards
Color filters are introduced at f. The voltage of the light source may
be regulated either by means of an iron resistance or manually by
means of a rheostat and voltmeter.
The null, or “dark,” current on the millivoltmeter, always present
in this apparatus, is designated as eo. To obtain the transmittancy of
a solution the cell containing the solvent is placed in the light beam
and the reading, e, is noted. The cell containing the solution is next
g €9 – 6 *
exposed and the reading, e3, noted. Then :== T, from which
1- to
—log tis calculated.
(b) HIRSCHMULLER APPARATUS
This instrument was first described briefly by Landt and Hirsch-
müller [29] and later in greater detail by Hirschmüller [34] in a Beer’s-
FIGURE 70.-Hirschmüller photoelectric colorimeter.
1, Mercury arc; 2, plug connector; 3, reactance; 4, spectral filter; 5, filter holder; 6, three-part condenser;
7, fixed aperture; 8, lens; 9, variable aperture; 10, tube; 11, diaphragms; 12 and 12, cells for solution and
solvent; 13, achromat; 14, photocell; and 15, iris diaphragm.
law study of beet sugars. Details of construction of the photometer
and of the Multiflex galvanometer are shown diagrammatically in
figures 70 and 71.
As shown in figure 70, the light source at 1 is a high-pressure
mercury arc operating on a 180- to 250-volt alternating current.
An inductance, 3, limits the current to 1.3 amperes. Fifteen minutes
after starting the lamp it burns with full intensity and with little
change in voltage. The emitted light consists of a weak, continuous
spectrum, which is disregarded, and a number of intense lines of the
mercury spectrum, the ultraviolet portions of which are absorbed by
the glass of the lamp. The wanted visible lines are isolated by means
of colored-glass filters analogous to those described under (e), p. 324.
The filters, held in the revolving holder, 5, are readily changeable.
The absorption cells, up to 5 cm in length, at 12 and 12", rest on a
revolving platform controlled by a knob above the housing and are
thus interchangeable. The light beam, defined by properly arranged
lenses and diaphragms, reaches the selenium barrier-layer photocell
with minimum divergence.
The response of the photocell to various light intensities is measured
by means of the Multiflex galvanometer of Lange [35], illustrated
diagrammatically in figure 71. The distinguishing feature of this

Polarimetry, Saccharimetry, and the Sugars 319
galvanometer is that the image of the straight lamp filament is reflected
by the galvanometer mirror and by fixed strip mirrors over the paths
represented by the broken lines to the 20-cm scale of the ground-glass
window at 5. The working distance of 1 meter is thus attained in a
relatively small housing. Using a pair of matched absorption cells in
the manner already described, the transmittancy of a solution,
T= deflection solution/de-
flection solvent, is ob- [i].”
tained for any of the three smſ
wave lengths.

(c) COMPENSATING VACUUM S
PHOTOTUBE PHOTOMETER | Tumº A
The apparatus described * A2% | |
below is a modification of J - &? |
the photoelectric colorim- *.* |
eter of Withrow, Shrews- - - | |
bury, and Kraybill [38] | |
and is used at the Na- |
|
tional Bureau of Standards |
for the measurement of |
transmittancy in sugar so- | |
lutions. Either a mercury º
arc with appropriate filters, | |
or a Mazda lamp with a |
560-mu filter, may be used | | | | |
interchangeably as a light | | |
source. The optical bench | |
accommodates absorption 1. | | | |
layers up to 20 cm in thick- \ | |
ness and the measuring | R- - |
bridge is simplified. The \;=pºp---sº
phototubes may be oper- +j *||aa =;
ated from either 115-volt
alternating- or direct-cur- FIGURE 71.-Multifler galvanometer of Lange.
rent, the latter being the 1, Lamp; 2, prism; 3, º 4, lens; 5, Scale; and
more satisfactory. The y te
apparatus is illustrated schematically in figure 72, and by figure 73.
The light source is at S. The mercury arc used is a vertical quartz
Uviarc, 22.5 cm over-all in length and 1.8 cm in diameter, giving an
arc about 7.5 cm in length. The lamp is fixed to the door of the lamp
housing, which is hinged so as to open downward. By lowering the
door, the mercury flows to the tungsten anode and the arc is struck
when the door is replaced. At either side, and close to the lamp, are
metal diaphragms with 12.5-mm openings. Fins on the diaphragms
aid in disseminating heat. The lamp housing is ventilated by open-
ings at the back and a cover with a chimney may be used. On either
side of the source, the instrument is symmetrical except for the
absorption-cell carrier, which is placed on the right side of the instru-
ment.
320 Circular of the National Bureau of Standards
On either side of the light source are lenses at Li placed so that the
source is in their focal planes, and at L2 are long-focus lenses, placed
so that an image of the Mazda filament is focused on the surface of
the cathode of the phototube. The diaphragms covering these lenses
have 12.5-cm openings. Between each pair of lenses is a 4-cm absorp-
tion cell containing a solution of CuSO4.5H2O, 45 g per liter, to remove
infrared and visible red from the mercury spectrum. Shorter cells
may be used and would require proportionately greater concentration
of the salt. In the large compartment at the right is a sliding brass
plate with two shallow grooves, as indicated, in which are placed
cylindrical absorption cells, one for the solution and the other for the
solvent. Either of these may be brought into the light beam, as
|-25++—4"—- 85"—-i-
S #| P
+
FIGURE 72.-Phototube photometer used at National Bureau of Standards for sugar
solutions.
desired, by means of the rod, R. The glass spectral filters are mounted
in blocks, F, in which are corresponding openings admitting the light
to the phototube. The latter are cesium oxide vacuum cells supplied
by the Continental Electric Co. When covered, the metal compart-
ment serves as light and electrical shielding. The whole is built upon
a bed plate of 0.5-inch pressed steel, which in turn rests on three steel
bars, each having a leveling screw at one end. The cover is sheet
aluminum connected to ground. -
The phototube may be operated from the 110-volt supply, direct or
alternating current, the cathodes or light-sensitive surfaces being
connected to the negative terminal of the direct current supply or to
ground through the 25,000-ohm resistors. The anodes or electron
collectors of the phototubes are connected through the ratio arms of
the bridge to the positive terminal of the voltage supply.
The arm at the right consists of two wire-wound radio rheostats in
Series, the nominal resistances of which are 10,000 and 1,000 ohms,
respectively. These are for coarse and fine adjustment in calibration.

Polarimetry, Saccharimetry, and the Sugars 321
The ratio arm at the left is a Leeds & Northrup four-dial decade
resistance box, range 1 to 10,000 ohms, and is used for the measurement.
The null instrument is a type R Leeds & Northrup lamp and scale
galvanometer, No. 2500, with b suspension, rated sensitivity, 0.0005
ua/mm.
To perform a measurement of transmittancy, the arc is struck and
allowed to burn during 10 minutes to reach full intensity. At the
same time the current is turned into the phototubes, which are
allowed also to “warm up.” A pair of matched absorption cells, of
proper thickness, with plane parallel end plates, and thoroughly
cleaned, are chosen. One is filled with the solution to be tested and the
other with the solvent. With the pair of spectral filters to give the
desired wave length in each beam, the solvent cell on the carriage is
centered in the beam at the right, and with the dials of the resistance
box set to read 10,000 ohms, the galvanometer scale reading is brought
FIGURE 73.-Phototube photometer, showing mercury arc, absorption tube, and other
accessories.
to zero by turning the rheostat knobs. By means of the 1,000-ohm
rheostat this may be done exactly. The galvanometer switch is
thrown off and the solution cell is centered in the beam. The galva-
nometer is switched on and the scale reading is brought to zero by
means of the resistance box. The dial reading is then the transmit-
tancy, T, of the solution. With the galvanometer well-protected
against vibration, these measurements may be exactly duplicated.
The galvanometer is sensitive to dial settings in the fourth figure
under favorable conditions of illumination, but accurate readings in
the third place are sufficient.
For routine quantitative measurements of sugar color, a 200-watt
Mazda projection bulb is used along with the special filters for 560 mu
described in section 4 (c), p. 314. These filters may be set in the
blocks to replace a pair of the mercury-arc filters.
(d) KEANE AND BRICE SUGAR PHOTOMETER
This apparatus was designed primarily for the industrial grading of
white sugars on the basis of (1) the appearance of a sugar in terms of

322 Circular of the National Bureau of Standards
its reflectance for white light, (2) the apparent color of an unfiltered
solution in terms of its transmittancy for red and green light, and (3)
the turbidity of the solution in terms of its transmittancy for red light.
Since the color filters used transmit very wide spectral bands, the
results obtained are not related to those obtainable with a spectro-
photometer, but are peculiar to the photocell-filter combination. The
following description of the instrument is condensed from the article
of the authors [28]. The optical arrangement of the photometer is
shown schematically in figure 74 and the wiring diagram is figure 75.
A beam of light from a 50-watt projection lamp, J, passing through
a color filter, F, is made parallel by lens, L, and is divided by a clear-
glass plate, A, roughly 10 percent of the light being reflected onto the
“compensating” photocell, P2, while the main beam passes through a
compartment containing an absorption cell, C. After reflection by a
mirror, M, the collimated beam strikes the standard white reflecting
surface, S, at an angle of 45°, and a cone of diffusely reflected light is
FIGURE 74.—Photoelectric photometer of Keane and Brice.
received by the “measuring” photocell, P1, placed directly above and
with its sensitive surface parallel to the standard reflecting surface.
A sliding shutter operated by screw, B, provides a means of making
small adjustments in the light intensity received by P2. The parts,
F, C, and S, are mounted on slides and can be withdrawn from the
light beam or replaced as required.
The diagram in figure 75 illustrates the compensating photoelectric
circuit of the apparatus. Pi and P2 are photronic cells in a parallel
connection with a 22-ohm mirror galvanometer, G, of sensitivity 0.36
pa/mm and a 35-ohm precision-wound, 12.5 cm diameter Leeds &
Northrup potentiometer rheostat, R. The uniform scale of the latter
is calibrated from 0 to 100. The conditions under which the scale
indicates light transmission or reflectance include (1) suitable photo-
cells, (2) a low resistance value for the potentiometer rheostat, and
(3) moderate illumination of the photocells.
For reflectance measurements, the granulated sugar is poured into
a metal dish 63 mm in diameter and 16 mm deep and the top surface
is carefully smoothed until it is flush with the edge of the dish. Slight
overfilling or underfilling will cause appreciable error, since the dis-
tance from the reflecting surface to the photocell is only 55 mm. The

Polarimetry, Saccharimetry, and the Sugars 323
reflectance, standard is an opaque white glass plate with a finely
ground surface having a reflectance of 0.856 relative to that of a freshly
prepared magnesium oxide surface measured in place in the instru-
ment. . With the standard white plate in position in the light beam,
the galvanometer is adjusted to read zero, the rheostat scale set to
85.6, the lamp turned on, and the shutter, B, moved until the galva-
nometer again reads zero. The standard plate is then replaced by
the sugar sample by moving the slide. The galvanometer deflects
and the circuit balance is restored by adjusting the rheostat. The
scale reading then indicates the reflectance of the sample relative to
magnesium oxide. A comparison of readings made by the authors
for individual samples indicated the necessity of screening the sugars
to uniform grain size.
For transmittancy measurements, a 150-g sample of sugar is dis-
Solved in distilled water at room temperature and, without filtering
is made up to 250 ml. The solution, free from air bubbles, is trans-
ferred to a 150-mm absorption cell with plane parallel end plates.
A reference cell, similar to, but only half as long as, the solution
cell, is also filled with distilled water. The reasons for using the 75-

ºf *H,
FIGURE 75.-Compensating photoelectric circuit of Keane and Brice.
Pl, Measuring photocell; P2, compensating photocell; G, galvanometer: R, potentiometer rheostat.
mm solvent cell are: (1) The sugar solution used contains only 51.2
percent of water; (2) water of this depth appreciably absorbs red light
beyond about 690 mu with a maximum absorption at 760 mp; and (3)
the red filter used, freely transmits light absorbed by the water, and
the photronic cell shows appreciable response to radiation in this part
of the spectrum. One starts with the 75-mm cell of water in the light
beam and, with the standard white plate in position, the scale is set
to read 100. After the circuit is balanced by turning screw B, the
water cell is replaced by the 150-mm solution cell and when the cir-
cuit is balanced by means of the rheostat, the scale indicates the trans-
mittancy of the solution. The transmittancies are measured first with
a blue-green filter (Corning light shade blue-green, No. 428, 3.4 mm
thick) and then with a red filter (Corning traffic red No. 245). The
apparent color index is then computed from the ratio of the trans-
mittancies by the formula T
- g
I.- 100(1 T,
and the index of turbidity by the formula
I,-100(1–T,).
Turbidity measurement is further considered in chapter XX,*p.341.
* Nees, [32] using a Lange photoelectric colorimeter [35], determines color and turbidity in the unfiltered
Solution with blue and yellow filters. The apparatus is first calibrated by reading the relative percentage
of absorption of blue and yellow light by a given unit of color and turbidity. ... From this relationship both
color and turbidity are calculated and expressed as the percentage of absorption of blue light.
324 Circular of the National Bureau of Standards
(e) MERCURY-ARC SPECTRAL FILTERS
The mercury arc is useful, not only for the wave-length calibration
of spectrometers, but because the intense light of three lines of the
mercury spectrum may be isolated in sufficient purity by means of
properly selected filters. It constitutes an admirable light source
for abridged spectrophotometry of sugar solutions, as indicated above.
Spectral filters for this purpose may be composed either of colored
glasses, single and in various combinations, or of dyed gelatine film
properly mounted. The composition of various glass spectral filters
is to the found in the paper by Gibson, Tyndall, and McNicholas [8],
and in the catalog of Corning Glass Works entitled “Glass Color
Filters.” The filters given in table 39 have been used both in visual
photometry and with the photoelectric apparatus described under
(c), p. 319. It is to be emphasized that when photoelectric cells are
used, high spectral purity is essential, and since all of the filters trans-
mit more or less red and infrared, this radiation must be removed from
the radiation reaching the photocell. This may be done by interpos-
ing a water solution of copper sulfate of such thickness and concen-
tration that the number of grams of CuSO4.5H2O per liter is equal to
178 divided by the length of the cell in centimeters. For visual
photometry the red may be removed by means of Corning Dark Shade
Blue-Green No. 430, 4 mm thick. In table 39 are given the mercury
wave length isolated, the designation of the glass components, the
thickness, and the transmission of each of the filters of this particular
set at the wave length isolated. There is also included a list of dyed
gelatine filters under the manufacturer's designation. These are
described in the catalog of the Eastman Kodak Co., Rochester, N. Y.,
under the title Wratten Light Filters. These filters also transmit
some visible red.
TABLE 39.-Mercury-arc spectral filters
Glass filters Wººn
Wave length- - - - - - - - - - - Designation of Corning glass------------------ Thickness T Filtºum.
77tpu Blue Purple Ult 77777)
ue Purple ra, 585------------------------ 3. 98
435.8------------------- §. §§y. • -- ~ * = ** - * * * * * - - - - - - - - - - - -w ºr - am -- ~ * 1, 89 } 22. 5 50
ellow Shade Yellow, 351--------------------- 2, 50 per
* - - - - - - - - - - - - - - - - - - - {}. 513. Tº TIII 6, 00 } 61. 5 || 77 Or 77 A
578---------------------
(576.9, 579.1) ------------ }Red Shade Yellow, 348------------------------ 6. 00 || 41.0 22
6. FILTER AIDS AND FILTRATION OF SOLUTIONS
(a) PREPARATION OF ASBESTOS [39]
Several subvarieties of both serpentine and amphibole are referred
to in the literature as being suitable for laboratory filter aids. A large
proportion of long fibers is desirable for the filtration of sugar sirups
and the variety chosen should be resistant to the drastic chemical
treatment described below, the purpose of which is to remove estremely
fine material that may cause cloudy filtrates, and other substances
that might affect the color of the solutions. Hard columnar fiber
Polarimetry, Saccharimetry, and the Sugars 325
bundles (sometimes 20 cm or more in length) should be broken to a
length of 3 or 4 cm and loosened sufficiently to allow easy permeation
of liquid. The asbestos fiber, in a suitable iron container such as a
sand bath, is treated with a solution of sodium hydroxide, specific
gravity 1.43 (40-percent NaOH), 250 ml to each 25 g. The vessel is
covered and the mixture is boiled for 30 minutes with occasional stir-
ring, no attempt being made to maintain the above concentration.
The mixture is filtered by suction in a Büchner funnel without paper
and washed with relays of clear tap water until substantially all alkali
is removed from the filter pad. The washed asbestos, after pressing
in the Büchner funnel, is transferred to a glass flask and treated with
a mixture of 250 ml of hydrochloric acid, specific gravity 1.20, and 25
ml of nitric acid, specific gravity 1.42, for each 25 g of asbestos orig-
inally taken. The fiber pad is disintegrated and mixed with the acid
by shaking and the mixture is heated for 30 minutes on the steam
bath. The contents of the flask are then diluted with distilled water,
filtered, and washed with hot distilled water until the washings give
no reaction for acid or for chlorine ions. The fiber is dried at 100° to
110° C and stored in a clean container.
Asbestos for general analytical purposes has been prepared in the
same manner. For the clarification of sugar solutions, three grades of
long-fibered asbestos, designated consecutively according to fiber
length as XXX, XX, and A * have been found satisfactory. Whether
the asbestos is crude fiber or acid-washed, it should be subjected to
the treatment described above for the removal of fines.
(b) ASBESTOS FILTERS
Several forms of filters are suitable for sirup filtration with asbestos.
A 25-ml or larger Gooch crucible fitted with a disk of 200-mesh bolting
silk to retain the asbestos is convenient and low-priced [40]. A good
grade of filter paper (not hardened) may be substituted for the silk.
Small Büchner funnels with filter paper also may be used. The size
of the filter should be chosen with regard to the amount of solution
to be filtered which, in turn depends upon the depth of color of the
solution. -
Jena glass filters [41] in the form of cylindrical funnels, 60- or 120–
ml capacity with 4-cm filter element, have proved very satisfactory.
These filters are designated as 11–G–1 and 11–G–2 for the 60-ml
capacity, and 11–a–G–1 and 11–a–G–2 for the 120-ml capacity. The
final figure designates the pore size of the filter element, No. 1 being
the larger. The pore size, No. 1, is used for preliminary filtration,
and the No. 2 for the final filtration.
To form the filtering pad, the asbestos in water suspension is poured
into the filter, sucked down with the aspirator, and packed tightly by
pressing and tapping with a flattened glass rod. The flat pad, which
should be about 5 mm thick when tightly packed, is then washed a
few times with water and drained by suction.
Where many samples are to be run daily, a battery of filters may
be arranged as shown in figure 76. Each filter or Gooch adapter is
fitted to an 8-ounce wide-mouthed bottle through a two-hole rubber
stopper, the other hole being fitted with a glass tee with a two-way
(Geisler) stopcock, which leads to a vacuum header, and which in
18 Powhatan Mining Co., Woodlawn, Baltimore, Md.
326 Circular of the National Bureau of Standards
turn leads to a central chamber connected with the vacuum pump or
water aspirator. Each suction tube passing from the filter to the
vacuum header may be closed by means of the stopcock so that the
filtering process for any individual unit may be interrupted without
interference with the others. The central vacuum chamber is con-
nected with a mercury manometer or other vacuum gage.
(c) PREPARATION AND FILTRATION OF THE SOLUTION WITH ASBESTOS [42]
A generous supply of solution should be available, the amount to be
taken depending upon the depth of color. For darker products, 100
g of solution may be sufficient, whereas 200 g or more may be neces-
FIGURE 76.-Peters and Phelps filter battery.
sary for white sugars. The stability of transparency is, in large part,
dependent upon high density. It is therefore considered necessary
that the dry-substance concentration of the solution be not lower than
60 Brix, which is compatible with reasonably rapid filtration. Time
is saved by dissolving and diluting on a weight basis. The required
weights of sample and water are calculated as follows:
g solution required XBrix of solution
Brix of sample
=g sample to be taken.
Then
g water to be added=g solution-g sample.
For nearly dry products of relatively high purity, such as 96 test
raw sugars, a sufficiently close approximation results if polarization is
substituted for Brix.

Polarimetry, Saccharimetry, and the Sugars 327
The calculated amount of sample to provide a 60-Brix solution is
weighed into a tared flask on a rough balance and weights equivalent
to the required water are added to the pan. A small amount of hot
distilled water is added and the flask is placed in a water bath heated
to 50° C and shaken to promote rapid solution. Hot water is added
to the flask a little at a time until the sample is dissolved. The flask
is dried on the outside and returned to the balance pan where dilution
to the required weight may be completed. Purified dry asbestos is
added to the solution in amount depending upon the quantity and
character of the suspended matter present. Usually 0.5 g will suffice,
but when slimy material is present and the solution is refractory in
filtration, 1 to 2 g should be used. The flask is loosely stoppered and
shaken gently at first until the warm air is expelled. The stopper is
then tightened and the flask is shaken vigorously to mix the contents
thoroughly and to permit the asbestos fibers and the suspended matter
to become entangled. The flask is returned to the bath and the solu-
tion is allowed to warm for a short time.
Although it is possible to obtain a satisfactory filtrate with a single
filtration, particularly in the case of easy filtering solutions, it is cus-
tomary to filter twice. Two filters are therefore prepared as directed
in section (b), p. 325. The first, or preliminary filter, immediately
before filtration, is warmed by washing with a small amount of hot
distilled water, which is aspirated from the asbestos pad as thoroughly
as possible. The warm solution is then added and a few milliliters
filtered to displace the water remaining in the pad when the suction is
closed off and a clean dry receiver is substituted. When the filtration
is resumed the remainder of the solution, or as much as the filter will
hold, is added. The pad is to be kept covered with solution during
the filtration, at the end of which the suction is stopped before the pad
becomes uncovered. The receiver is detached and returned to the
bath for further warming while the second filter is being rinsed with
hot water and drained. The second filtration is performed exactly
as the first but no asbestos is added to the first filtrate. The main
portion of the filtrate is collected in a clean receiver. This filtrate is
cooled and adhering condensed water is wiped from the neck of the
bottle which is then closed with a clean, dry stopper and shaken to
mix the contents throughly. The refractometric Brix of the optical
filtrate is determined and c (g dry substance per 1 ml) is obtained by
reference to table 114, p. 632). The solution, if not too dark, is
now ready for photometric observation.
(d) PREPARATION OF DIATOMACEOUS EARTH AND FILTRATION
Diatomaceous earth, also known as infusorial earth or kieselguhr,
on account of its availability and ease of application, is preferred in
factory laboratories for the clarification of sugar solutions for colorim-
etry. As noted by Balch [57], variable quantities of earth must be.
used to obtain satisfactory clarification, depending upon the nature and
amount of suspended matter present as applying to different grades
of sugar products. Zerban and Sattler [58] found that the same state-
ment applies to products of a single grade (raw sugar), and that there
is a gradual falling off in — log tin some cases with increasing quantities
of earth used, and that more earth than the quantities tested (5 g to
50 ml of 60 Brix) would have to be used to reach a limiting effect.
328 Circular of the National Bureau of Standards
Experience at this Bureau [42] and as reported elsewhere [59] has led
to the belief that diatomaceous earth has a distinct decolorizing effect
upon sugar Solutions beyond the removal of visible turbidity, depending
upon the quantity of earth used and the number of filtrations.
On the basis of time consumed in obtaining satisfactory filtrates, a
comparison of clarification with asbestos or with diatomaceous earth
probably leaves little to choose, much depending upon the develop-
ment of technique. For technical purposes, where an error of a few
percent is of little consequence, and where the employment of earth
is more convenient, its use is recommended, particularly for the filtra-
tion of thin juices.
Diatomaceous earth should be treated for the removal of interfering
substances, as described below.
Methods for purifying diatomaceous earth by means of dilute
hydrochloric acid have been described by Zerban
and Sattler [58] and by Honig [60]. In the method
employed at this Bureau, 100 g of earth in an
Erlenmeyer flask is treated with 400 ml of strong
hydrochloric acid and 40 ml of strong nitric acid.
The contents of the flask are mixed and heated
for 30 minutes on the steam bath. The mixture
is then diluted with 2 liters of cold water, and
the earth is allowed to settle for a few minutes
when the liquid is decanted. The earth is then
filtered with suction in a Büchner funnel and
washed with relays of dilute hydrochloric acid
(20-percent concentrated acid by volume) until
the filtrate shows absence of iron, then with dis-
tilled water for removal of hydrochloric acid.
The product is dried at 110° C.
Zerban and Sattler boil 75 g of earth with a
mixture of 100 ml of concentrated hydrochloric
acid and 900 ml of distilled water and filter hot,
then wash thoroughly with hot water. This
treatment is repeated three times, and the material
is dried and ignited in a muffle furnace.
FIGURE 77.-Filter ap- For the clarification of solutions of washed raw
§§º *” or better-grade sugars, 100 to 200 ml of the 60-
o Brix solution is treated in a suitable flask, with 2
percent of the purified earth based on the weight of solids. For
badly contaminated products, more earth must be used. The flask
is closed with a rubber stopper and vigorously shaken, and the mixture
is filtered through a double layer of a good grade of paper, 5.5 cm in
diameter, in a Büchner funnel. The paper should first be washed
with a little water. When the filtrate has become clear, a clean, dry
receiver is substituted and the filtration is completed. As suggested
by Balch [57], receivers may be changed without the necessity of
breaking the vacuum if the Büchner funnel is connected to a fractional
distillation receiver designed for distillation under reduced pressure.
To complete the filtration without breaking the vacuum, Zerban and
Sattler use the apparatus shown in figure 77.
Balch states that the more resistant the suspended material is to
filtration, the more earth must be used which may amount to as much

Polarimetry, Saccharimetry, and the Sugars 329
as 10 percent on Solids, and for cane juices or lime-defecated juices the
maximum will undoubtedly be necessary.
Honig [60] treats 200 ml of 55-Brix solution of sugar in a 300-ml
Erlenmeyer flask with 2 g of prepared Hyflo Supercel. After mixing,
the solution is filtered on a Büchner funnel through a hardened paper
that has been slightly moistened beforehand. The suction is turned
on and the entire amount of the mixture is added to the filter. The
filtrate is refiltered five times through the original layer of filter-aid,
finally being collected in a clean receiver.
7. DILUTION OF COLOR [40, 42]
A dilution of color is necessary when the saccharine product is too
dark to permit good photometric readings, particularly when observa-
tions are to be made in the blue portion of the spectrum. Dilution
with water alone causes separation of colloids which produce turbidity.
The dilution may be accomplished, however, by the addition of a
concentrated, highly decolorized sugar solution to the turbid dark
solution, or by mixing a known weight of white sugar with the sample,
and diluting.
To prepare the diluent sirup, a 60–Brix solution of the best obtain-
able grade of white sugar is heated in a bath to 90° C. Decolorizing
carbon equivalent to 2 percent of the weight of sugar solids is added
and the mixture is warmed and shaken during 15 minutes. Prepared
kieselguhr (see section 6 (d), p. 327) 5 percent on solids, is added
and mixed with the solution, which is then filtered through paper in a
large Büchner funnel, cloudy first-runnings being returned to the filter.
The solution is refiltered through an asbestos pad. The color remain-
ing in the sirup after a single carbon treatment depends upon the color
of the original sugar. Usually there is detectable light absorption
in the blue part of the spectrum, but this should be so slight as to be
negligible in the final results. It is possible, by repeated carbon treat-
ment, to prepare solutions that absorb no mercury blue-violet in a
20-cm thickness of liquid column.
The dilution of color with sirup may be carried out on a volume or a
weight basis. The volume basis is more rapid, but the weight basis
is more precise, since deduction may be made for any absorption by
the diluent. When dry white sugar is used, the dilution is necessarily
on a weight basis. In the following description of the procedure the
same colored product and the same diluent sugar were used, the latter
being a specimen sold as pure sucrose. In procedures (a) and (b) the
diluent solution was not treated with decolorizing carbon but was
filtered through asbestos.
(a) VOLUME BASIS
The two solutions, which should be at the same temperature (20° to
25° C), are pipetted into a flask, the pipettes used being graduated to
contain a definite volume. Both pipettes are rinsed with the Solution
in the flask, after it is mixed, in order that the adhering Solution may
be of the same concentration as that in the flask. The mixture is
filtered through asbestos at room temperature, and the transmittancy
is measured with the photometer. The following example illustrates
the calculations.
330 Circular of the National Bureau of Standards
Colored solution, refractometric Brix_ _ _ _ _ _ _ _ _ _ _ _ 60. 3
Colored solution, c, from table 114- - - - - - - - - - - - - - 0.7768 g/ml.
Colored solution, volume taken -- - - - - - - - - - - - - - - - 20. 0 ml.
Diluent solution, volume taken -- - - - - - - - - - - - - - - - 100. 0 ml.
The mixture then contains one-sixth of its volume of colored solu-
tion, and c, the colored dry substance of the mixture, therefore bed mes
0.7768/6=0.1295.
Thickness of absorption cell, b, -2.0 cm.
T at A436 mp by photometer=0.34.
—Log TM-48s from table 129–0.4685.
Since —log t-1/cbX (—log T),
1
—Log t=0.155.5×0.4685= 1.8089.
(b) WEIGHT BASIS
This procedure is longer than (a) but is capable of yielding more
precise results, since a correction is introduced for any absorption by
the diluent sirup. It is therefore necessary to know the dry-substance
content of both colored solution and diluent and —log tof the diluent
at the wave lengths selected. The same values are then determined
for the mixture and the corrections are applied.
A portion of the colored solution is weighed in a tared flask or
beaker, and the diluent in the desired amount is added and the whole
reweighed and mixed, the weight of added diluent being found by
difference. The mixture is warmed to 60°C, filtered with asbestos,
cooled, and the refractometric Brix is determined. The transmittancy
of the mixture in appropriate cells is then read at the selected wave
lengths with the photometer. The manner of applying the corrections
is illustrated by the following example, in which the values for the
diluent sirup are first determined.
Example.—In the diluent sirup Brix=60.9, corresponding to c=0.7867 (table
114, p. 632). Cell length, b = 20 cm. TX-550=0.887, TM-435–0.699. From table
129 then we obtain — log TM-560= 0.0521, -log TM-436= 0.1555.
Substituting in the Lambert–Beer equation, we have
I
-log tx-560= 0.73675& 20 X 0.052] = 0.0033.
-log tx=436 = wº X 0.1555 = 0.0099.
In the colored solution, Brix=60.3 corresponding to c = 0.7768.
Weight of colored solution taken - - - - - - - - - - - - - - - - - - - - - 12. 415 g.
Weight of mixture after adding diluent--- - - - - - - - - - - - - - 73. 480 g.
Difference= weight of diluent - - - - - - - - - - - - - - - - - - - - - - - 61. 065 g.
Weight of dry substance in colored solution = 60.3 percent of 12.415 = 7. 4862 g.
Weight of dry substance in diluent=60.9 percent of 61.065- - - - - - - - =37. 1886 g.
Weight of dry substance in the mixture - - - - - - - - - - - - - - - - - - - - - - - - - = 44, 6748 g.
_ 7.4862 ---
Percentage of colored dry substance= 44.6748 - " - = 16. 75
After filtration and cooling, the refractometric Brix of the final filtrate was
62.0, or c=0.8049. Assuming that the proportions of colored and diluent dry
substance do not change upon concentration, we have in the final filtrate c= 16.75
percent of 0.8049-0.1348 and diluent dry substance, cp=0.8049–0. 1348=0.6701.
The photometric readings of this mixture in a 2-cm cell were TX-580–0.72 and
TX-435-0.33. Corresponding to -log TM-550–0.1427 and – log TM-436–0.4815.
Substituting in the Lambert–Beer equation, we have
—log tx=580– wińsº 0.1427 = 0.5293,
Polarimetry, Saccharimetry, and the Sugars 331
—log “-º-Wiwisza” 0.4815 = 1.7859.
In the mixture it is obvious that the absorbancy, which we shall call —log TM, is
made up of two parts, the – log T of the colored solution and the -log Tp of the
diluent solution, that is,
(a). —log T- (-log TM) — (–log TD).
The value of — log TD may be calculated by the Lambert-Beer law if we know the
concentration, cp, of the diluent dry substance in the mixed solution and its spe-
cific absorptive index, — log to, for each wave length as follows:
g —log TD= cob (–log td).
In the mixture, we have already found by difference that co– 0.6701, and – log to,
as already determined in the diluent to be 0.0033 for X = 560, and 0.0099 for
X=436. Substituting these values in (b), we have
For X=560, -log TD = 0.6701 X2×0.0033=0.0044.
For A=436, -log TD=0.6701X2×0.0099–0.0133.
Substituting these values of — log TD in (a), we have
For X = 560, -log T-0.1427–0.004.4–0.1383
For X=436, -log T-0.4815–0.0133=0.4682
These are now the corrected values for — log T in the mixture and we recalculate
the values of — log t
— log *-*-Wisłºx 0.1383= 0.5125.
* log tx=436 -ºxº × 0.4682= 1.7351.
The differences from the uncorrected values for the mixture in procedure (b)
are found to be 3.28 percent for A= 560 and 2.93 percent for X=436. In procedure
(a) the difference is 4.25 percent, the divisor in each case being the corrected value.
(c) DILUTION WITH SOLID SUGAR
A high-grade, refined, white sugar selected for absence of color may
be used to advantage for color dilution. A large quantity, when
properly stored, may be kept on hand over a long period without
danger of serious change in color. The absorption data may be
determined once for all and applied as a correction when necessary.
The preparation of a diluent sirup is thus avoided.
A portion of the white sugar is weighed in a sugar dish or other
suitable vessel. To this is added the colored product (with known
Brix) in quantity to produce the desired color in the mixture, and the
weights of each are recorded. The mixture is transferred with a small
quantity of hot water to a tared flask, the dilution to 60 Brix is com-
pleted and the warm solution filtered through asbestos (section 6 (c),
p. 326). After cooling the solution the refractometric Brix is deter-
mined and the transparent solution is measured photometrically.
The weight of water required for dilution to 60 Brix may be cal-
culated if the total dry substance of the mixture is known. For
example, if 5 g of 80–Brix molasses is added to 60 g of white sugar
(assuming 100 percent of dry substance in the latter), then the weight
of total dry substance in the mixture is 64 g. The weight of a 60-Brix
solution of the mixture is then 100X64/60=106.7 g, and the water
required is 106.7–64=42.7 g.
To find the colored dry substance in the mixture after the asbestos
filtration the directions as given in procedure (b) are followed. In
the present case, for example, as we have seen, 5 g of 80-Brix molasses
contains 4 g of dry substance. Adding this to the 60 g of dry sub-
stance of the white sugar, we have 64 g of total dry substance in the
mixture. Of this, 4/64, or 6.25 percent, is colored dry substance,
332 Circular of the National Bureau of Standards
Assuming that the refractometric Brix of the cooled asbestos filtrate
was found to be 61.2, ocrresponding to 0.7917 g of dry substance per
1 ml, then the colored dry substance is 6.25 percent of 0.7917, or 0.0495
g per 1 ml, the value to be taken for c in the Beer's-law equation.
If correction for absorption of the white sugar is necessary, the cal-
culations are made in exactly the same manner as in procedure (b).
(d) CALCULATION OF BRIX
In case the Brix (percentage of dry substance by weight) of a
heavily colored product is unknown, the original Brix may be cal-
culated from data obtainable in procedure (b) or (c) and the results
are as nearly correct as those obtained by methods usually applied to
low-grade products. To obtain the Brix of the colored sample the
weight of dry substance in the diluent is subtracted from the weight
of dry substance in the mixture (determined from the weight of the
mixture and its Brix before filtering). The remainder is divided by
the weight of the colored sample and the quotient is multiplied by 100.
Or, expressed as a formula:
(gmxt. XBrix % mxt)–(g diluent XBrix % diluent).
g of sample
Brixsample=100X
For example, if the Brix of the colored sample in procedure (b) were
unknown and if the refractometric Brix of the turbid mixture as
found immediately after mixing was 60.8, then
(73.48×0.608) — (61.065× 0.609)
12.415
When procedure (c) is used, the weight of diluent dry substance is
represented by the weight of white sugar taken, and the mixture may
be dissolved and diluted by warming to 50° C in a bath, but, as
noted before, in order to determine the unknown Brix of the colored
product, the solution must be cooled and thoroughly mixed, then
weighed, and its refractometer reading made before filtering. These
ºtions are carried out with the substances in the original tared
T18,SEQ.
Brix of sample=100X = 60.31.
8. SUMMARY OF THE PROCEDURE
When dilution of color is unnecessary:
1. Make up a 60-Brix solution of the sugar product.
2. Filter with asbestos as described.
3. Determine the refractometric Brix, and from table 114, p. 632,
find the corresponding grams of dry substance per milliliter (=c), or
calculate c from refractometric Brix and true density thus,
Brix Xtrue density.
--- 100
4. Fill a parallel-sided cell of suitable thickness with the solution,
and a duplicate cell with the solvent (water) to be placed in the com-
parison beam. Read the transmittancy on a spectrophotometer, a
simplified spectrophotometer, or other comparator capable of measur-
ing transmittancy for monochromatic light.
Polarimetry, Saccharimetry, and the Sugars 333
5. Record
(a) c-grams of dry substance per milliliter of final filtrate.
(b) b = thickness of the absorption cell used.
(c) T or -log T for each wave length as read.
6. Reduce the readings obtained to unit basis as regards concentra-
tion and thickness by calculating specific absorptive index, —log t
from the equation, —log t-1/cb (–log T).
When color is diluted record also:
7. For volumetric method, procedure (a):
(a) Grams of dry substance per milliliter (=c) of turbid solu-
tion.
(b) Volume of turbid solution.
(c) Volume of diluent solution.
(d) Grams of colored dry substance per milliliter in mixture.
8. For gravimetric method, procedure (b), for correction of —log tº
(a) Refractometric Brix of diluent sirup.
(b) Weight of diluent sirup or solid sugar.
(c) Specific absorptive index, —log to of diluent.
(d) Refractometric Brix of colored sugar product.
(e) Weight of sugar product taken.
After filtration with asbestos, record:
(f) Refractometric Brix of final filtrate.
For qualitative and quantitative investigation of sugar color,
readings are made at wave-length intervals of 10 or 20 mg over that
part of the spectrum included between 420 and 700 mg. For routine
technical purposes a reading at the single wave length 560 mp is
sufficient, which, with the use of the filters designated for the purpose,
may be done directly with a simple instrument or by calculation from
º at A546.1 and X578 m.p. of the mercury arc (see paragraph 10,
elow).
9. For some purposes it is convenient to reduce —log tat 560 mp.
to n units of coloring matter (equivalent to m sugar color degrees).
This is to be done by dividing —log thy the absorption unit, —log t,
of the standard at the same wave length. This value (–log ti) for
the provisional standard adopted is 0.00485 at A560 mp for all types
of coloring matter usually occurring in sugar products. It is now
known as the Peters and Phelps color unit. One absorption unit at
560 mp is equivalent to one unit of coloring matter which evokes a
color sensation of one color degree. The value, m, absorption units,
represents the sum total effect of absorption at all wave lengths. It
is therefore a measure of n units of coloring matter in 1 g of sugar-dry
substance and may be used as the final value to be regarded as charac-
teristic of the sample measured.
In all cases additional measurements at other wave lengths than
560 mp, especially the shorter wave lengths (for example, the Hg
lines 546 mu and 436 mp), may be made to yield valuable information
as to changes taking place in various processes of manufacture, espe-
cially when studied as absorption ratios.
10. When the mercury arc is used as light source, a reading at 560
mu may be obtained by a process of interpolation between readings
at 546.1 and 578 mu or by applying a correction factor as follows:
Deduct 48 percent of the difference between —log tº at A546.1 and
X578 from —log tat \546.1; the result is —log tat A560.
323414°—42 23
334 Circular of the National Bureau of Standards
9. COLOR STANDARDS FOR SOLID SUGARS
Reference has already been made in this chapter to the measure-
ment of reflectance from a smoothed surface of solid sugar, using cer-
tain of the photometric instruments described in previous sections.
In some countries duty on imported sugar is charged according to
color as well as to polarization, i. e., a higher duty is paid on a sugar
lighter than a certain standard than on one that is darker. As a basis
for color comparison, the well-known Dutch Standards are used.
The Dutch color standards consist of a series of samples of crystalline
sugars of approximately equal gradations of color ranging from No. 7,
which is very dark, to No. 25, which is almost white. Number 16
Dutch Standard is the technical color distinction in some countries
between refined and raw sugars. The color grade of any given sample
is determined by comparison with the standard series. The standards
contained in sealed bottles are prepared for the sugar trade by a firm
in Holland. They should be renewed once a year because of the
tendency of the colors to change.
Color standards for soft sugars were prepared from ground glass
by Wills (61]. The glass specimens (designated as colorless, light
brown, dark amber, and uranium yellow) after grinding, were mixed
in varying proportions and graded to give gradually increasing color.
In all, 26 samples were formed. Later, the reflectance of these samples
was measured with a Keuffel & Esser color analyzer and any necessary
adjustments were made.
Raw-sugar color standards were prepared by Spengler and von
Heyden [62) by coating white sugar crystals with yellow ochre (dark),
cadmium yellow, and Norit, in various proportions. The pigments
were first thoroughly mixed with a 67-percent solution of white sugar.
The crystalline sugar, after mixing with the pigment suspension, was
centrifuged and the coated sugar first air-dried, then heated in the
oven for 9% hour at 70° to 80°C. The cooled samples were then placed
in containers having Cellophane windows.
10. DECOLORIZING EFFICIENCY OF CARBONS
(a) FINELY DIVIDED CARBONS
(1) DETERMINATION OF MOISTURE.-Decolorizing carbons are
capable of retaining several percent of moisture, depending upon
humidity conditions, and the main sample should therefore be stored
in a tightly stoppered bottle. In order to maintain a uniform basis
of comparison among different lots of carbon, it is necessary that
the results of decolorizing tests be calculated to moisture-free material.
Approximately 2 g of carbon is weighed in a large, tared weighing
bottle provided with a stopper, and heated 12 hours or overnight in
an oven maintained at 150° C. At the end of the heating period, the
bottles are stoppered and transferred to a desiccator while still warm.
The bottle with contents is weighed after cooling. The loss of weight
of the sample is calculated to percentage of moisture.
(2) DECoLoRIZING EFFICIENCY.—The removal of sugar color from
solutions by carbon has been shown by several investigators [43, 44,
47, 48, 49, 50] to follow the general adsorption equation, or isotherm,
expressed by Freundlich [51, 52] as follows:
QC }
;=kC wn,
Polarimetry, Saccharimetry, and the Sugars 335
where a is the amount of color removed by m grams of carbon, C is
the amount of color left in the treated solution at equilibrium, and k
and 1/n are constants, which for any given solution are characteristic
of the carbon. -
Writing the Freundlich equation in logarithmic form, we have
log ;-log k++ log C,
the equation of a straight line. If log ºſm as ordinates is plotted
against log C as abscissas on rectangular coordinate paper, log k is
determined as the value of the ordinate, where C= 1 (or 100, where
percentage of decolorization is used), while 1/m represents the slope of
the isotherm. The factor 1/n is equal to the tangent of the angle
formed by the isotherm with the log C axis. The values for C and a.
are best expressed in terms of percentage of the color of the original
solution before treatment. This in turn may be in terms of —log t,
–log T, or any of the usual color units. The value of m may be
expressed as grams of carbon, or as percentage carbon on sugar-dry
substance.
The extent of decolorization of sugar solutions by a carbon is
dependent upon several factors, among which are time of contact,
temperature, concentration, pH, and nature of the sugar product [49].
In comparing carbons, therefore, it is necessary that these conditions
be kept uniform. Also, it is generally agreed that the test material
should be similar to that to be treated on the large scale. q
As test materials, diluted molasses or high-density solutions of raw
Sugar are most frequently used in the sugar industry. The former
permits the more rapid work, whereas the latter is capable of affording
more accurate results which may be made directly applicable to large-
scale practice. Washed raw sugar, dried at the ordinary temperature
and well mixed, may be stored in large quantity and is recommended
for the isotherm test.
Using washed raw sugar, 500 g is dissolved in 350 ml of water at
90° C, and 20 g of kieselguhr (or more if necessary) is added and
mixed. The mixture is filtered in a large Büchner funnel fitted with
two layers of paper (Whatman No. 42 or equivalent) which has been
moistened and the excess water removed by suction. Small quan-
tities of the mixture are filtered at first, and, if the filtrate appears to
be perfectly clear, the main portion is filtered. In case of cloudy
first-runnings, the mixture may be added little by little until a suffi-
cient amount of kieselguhr has become deposited to give a clear
filtrate. The funnel is then transferred to a clean receiver and the
filtration completed, including the cloudy first-runnings. The
filtrates may be improved by a second filtration, through asbestos,
using a 120-ml Jena No. 1 funnel. The solution is cooled, thoroughly
mixed, and the Brix is determined with the refractometer.
For convenience, such amounts of the solution are taken for carbon
treatment as to contain 100 g of dry substance each (found by divid-
ing 100 by the Brix as a decimal, thus 100/0.60=166.67 g). This
amount is weighed to within 0.1 g in each of four tared 250-ml Erlen-
meyer flasks. These are placed in a bath held at 90° C and allowed
to warm. In the meantime, 4 portions of the carbon under test are
weighed out (to 1 mg) equivalent to 0.5, 0.7, 1.0, and 1.5 g (or percent
336 Circular of the National Bureau of Standards
on sugar solids), moisture-free basis, each weighed portion being
placed in a scoop or trough made by bending a 3- by 4-inch sheet of
thin aluminum or brass. It may be necessary to vary the quantities
of carbon from those given, depending upon the color of the solution
and the decolorizing ability of the carbon. A weighed portion of the
carbon is transferred to each flask, which is shaken continuously in
the heating bath for 15 minutes. The carbon is best removed by
filtration on an asbestos pad, using a Jena No. 1 filter. For paper
filtration, approximately 1 g of kieselguhr is mixed with the contents
of each flask, which is filtered by suction through a double layer of
Whatman No. 42 paper, 7.5 cm in diameter, in a Büchner funnel. A
battery of four filters with clean, dry receivers may be arranged and
an extra receiver used for starting the filtration of each solution, in
turn. When the filtrate becomes perfectly clear, the filter is placed
in its receiver and the filtration completed. The decolorized solutions
are cooled and thoroughly mixed, the refractometer Brix of each is
determined, and the solutions, including the original undecolorized
liquor, are evaluated photometrically, preferably at 560 mp, the
thickness, b, of the light-absorbing layer being governed by the color
of the solution. From the Brix, layer thickness, and photometer
readings (giving c, b, and T for each solution), —log tº is calculated
as already described. These values of —log t, without conversion
to color units, are used for computing the values for plotting the
isotherm.
Table 40 illustrates the manner of computing the isotherm data.
The values of C are found by (–log taecol./—log torig.) × 100 to give
a whole number and ac= 100— C. The values of m as given may be
called the percentage of carbon on saccharine dry substance.
TABLE 40.--Computation of data for the isotherm in figures 78 and 79

7m =grams —log t, 560 -
0.0 0.2090 100.0 | - - - - - - - - || - - - - - - -
... 5 . 0316 15. 1 S4. 9 169, 8
... 7 . ()211 10. I 89.9 I28.4
1. 0 . 0.136 6. 5 93. 5 93. 5
1, 5 . 0083 3.9 96.1 64. 1
The values of log a ſm may now be plotted against log C as rectangu-
lar coordinates, or as recommended by Sanders [45], a ſm and C are
plotted on double logarithmic paper, as shown in figure 79, the data
being those of table 40. -
Diluted molasses is preferred by many as a material for the de-
colorization test, since the solutions are easily filtered without suction.
Diluted molasses is unstable in color, and stock solutions should
therefore be prepared at least daily. This stock solution should not
be too dark for ease of color determination or so light that it is too
easily decolorized.
The procedure as outlined by Sanders [44] is as follows: Equal
volumes (150 ml) of the molasses are pipetted into five 250-ml Erlen-
meyer flasks. These are placed in a water bath and heated to 90° C.
On each of five strips of white glazed paper 1 g of Filter-Cel is placed.
Four portions of carbon are weighed, using, for instance, 0.1, 0.2,
Polarimetry, Saccharimetry, and the Sugars 337
0.4, and 0.7 g weighed to the nearest mg, allowance being made for
the moisture content of the carbon. Each weight of carbon is placed
on the Filter-Cel on each of the strips. The Filter-Cel alone is added
to one of the flasks and the mixture of Filter-Cel and carbon to the
other four. The heating is continued during 10 minutes after the
addition, the flasks being shaken continuously. The flasks are
removed from the bath and their contents filtered through paper
on separate 60° funnels. Cloudy first-runnings are discarded or
returned to the filter, only brilliantly clean filtrates being accepted
for colorimetry. After cooling, the filtrates are measured photo-
metrically, preferably at wave length 560 mp. Concentration of dry
substance is not taken into account in this procedure. Thicknesses

H-
---
ſ
2OOH-
!-
#
wº-
O 1–––––––––––––––––––––
C 25
ADSORPTION ISOTHE RMS
FIGURE 78.-Adsorption isotherms of three decolorizing carbons.
C Concentration of coloring matter remaining in Solution plotted against w/m, where a is the amount of
coloring matter removed by m grams of carbon.
(d) are reduced to 1 cm by dividing —log T as found or calculated
from the photometer reading, by the length in centimeters of the
cell used. If Meade-Harris color units are used, the number of units
found, corresponding to the photometer scale reading, are divided
by the cell thickness in centimeters.
Depending upon the system used, either —log T or the Meade-
Harris color unit of the untreated molasses solution is taken as the
basis for calculating the percentage of original color remaining, (C),
and the percentage of color removed, (a). Knowing m from the weight
of carbon, a ſm is computed, and the results are plotted on double
logarithmic paper, as recommended above.
338 Circular of the National Bureau of Standards
Sanders [45, 46] has applied the adsorption isotherm to calculate
the amount of carbon to be used to reach a desired degree of decolori-
zation and also to compute the decolorization and the carbon required
in countercurrent work.
Although one may read the values of a/m and C from the isotherm
plot and may calculate m from the relation a + C= 1 (if color is ex-
pressed as a fraction), this computation is done more easily by
reference to the nomograph shown in figure 80.
This nomograph solves the equation Y/M- K(1–Y)”. This is
the same as a ſm =kC**, where the color is a fraction of the original
|OOO
#
|OO
| | | | | | | | | | | 1–1–1–1–1–1–
o iO |
ADSORPTION ISOTHERMS
FIGURE 79.-Adsorption isotherms of the same three decolorizing carbons shown in
figure 78 (plotted on a logarithmic scale).
k, A constant (value of ordinate, where log C-1); 1|m, a constant (slope of the isotherm or tangent of the
angle formed by the isotherm with the log C axis). -
color, a =y and C= 1–y. To exemplify the use of the chart, let us
suppose that the values for K and 1/m were found to be 3 and 0.610,
respectively, and that it is desired to know how much carbon is neces-
sary to remove 70 percent of the color. On figure 80 draw a straight
line from 1/m =0.61 to Y=70, and extend this line to the MK
axis. The line extended cuts this axis at 1.45. Since K=3, then
M= 1.45/3=0.483 g (or pounds) of carbon per unit volume of solution.
In describing a carbon in terms of K and 1/n, it is necessary to adopt
standards of mass and volume of carbon and solution, respectively.
(b) GRANULAR BONE BLACK
The sample of bone black may be pulverized and tested for decolor-
izing efficiency in the same manner described for the char powders.
However, since the two kinds of carbon differ so greatly in grain size

Polarimetry, Saccharimetry, and the Sugars 339
and in other properties, and since the mode of application in practice
is different, the refinery chemist prefers to use a method that is more
nearly representative of practical working conditions.
Experimental methods of evaluating bone chars are described by
Wayne [53] and by Knowles [54], both of whom apply the char to
the sugar solution on a weight basis. Blowski and Bon [49] apply
the carbon on a volume basis. They place 170 ml of bone char in a
500-ml flask containing 10 ml of Filter-Cel and add 200 ml of a
47.5-Brix solution of crystallizer remelt sugar. The mixture is shaken
and digested 3 hours on the water bath with 30-second periods of
shaking every half hour. The mixture is decanted into paper filters
and allowed to filter overnight. A blank and an arbitrary standard
/00–
80–
33-
33
40–
30– — O. O
wºm i-O. A
2O -: T-02
3 Lo.3
- P-04
/O- –05
8– 0.6
é- of
3– -0.6
* — -0.9
3– - o ż
* i– /, /
//A. & – & **, :- /2
# — /3
# O F-/*
7–5 Y i-/J
o6– — 46
0.7 —
O.6— :- / 7
o,5- – 48
O4– L/2
os- –20
O. 2–
O.M. E
Y-//((-7°
FIGURE 80.-Nomograph for calculating, from the isotherms, the amount of carbon
required to reach a desired degree of decolorization.
char are submitted to the test in parallel. The color remaining in
each filtrate is determined and the decolorizing efficiencies are com-
pared with that of the arbitrary standard.
In the Spencer-Meade handbook [55) is described a procedure in
which the weighed bone black is placed in cylindrical copper funnels,
diameter 4 inches and height 15 inches, each provided with an outlet
pipe and cock at the bottom. The char rests on a perforated copper
plate covered with cloth. The funnels are placed in a water bath,
provided with suitable openings for the outlet cocks and are filled to
within a few inches of the top with the chars to be compared, the
weight of char in each filter being the same.


340 Circular of the National Bureau of Standards
A 55-Brix solution of a molasses sugar clarified by filtration with
kieselguhr is used for the test. The liquor is heated to 165° F (73.9°C)
and equal portions are added, little by little, to avoid air pockets.
After the char is covered, the remainder of the liquor is poured into
the filter. The temperature of the water bath is maintained at 160°
to 170° F (71.2° to 77.2° C) for several hours, and the liquor is then
drawn off through the outlet cocks. The color of the filtrates and of
the untreated liquors are compared.
In this procedure it may be necessary to clarify the char filtrates,
if char particles are present, by further filtration with kieselguhr, and
changes in the concentration of dry substance may be detected by
means of the refractometer.
11. REFERENCES
[1] K. Ventzke, Z. Ver, deut. Zucker-Ind. 10, 381 (1860); 11, 495 (1861).
[2] K. Stammer, Z. Ver. deut. Zucker-Ind. 11, 41 (1861).
[3] F. J. Bates and associates, Int. Sugar J. 22, 654 (1920) (abstract).
[4] H. H. Peters and F. P. Phelps, Tech. Pap. BS 21, 261 (1927) T338.
[5] L. Eynon, Committee on Publication (1936), 7 & 8 Idol Lane, London,
E. C. 3, England.
[6] K. S. Gibson, J. Opt. Soc. Am. & Rev. Sci. Instr. 10, 169 (1925); 11, 359
1925).
[7] K. S. Gibson and H. J. McNicholas, Tech. Pap. BS 12 (1919), T119.
[8] K. S. Gibson, H. P. T. Tyndall, and H. J. McNicholas, Tech. Pap. BS 13
(1920), T148.
[9] K. S. Gibson, J. Opt. Soc. Am. 24, 234 (1934).
[10] H. J. McNicholas, BS J. Research 1, 793 (1928) RP30.
[11] Spectrophotometric Equipment (Bausch & Lomb Optical Co., Rochester,
N. Y.
[12] Optical Instruments of Recent Design, Bul. 126 (The Gaertner Scientific
Corporation, 1201 Wrightwood Ave., Chicago, Ill.)
[13] C. W. Keuffel, J. Opt. Soc. Am. & Rev. Sci. Instr. 11, 403 (1925).
14] Advertising Leaflets, Palo-Myers, Inc., 81 Reade St., New York, N. Y.
5] G. P. Meade and J. B. Harris, J. Ind. Eng. Chem. 12, 686 (1920).
6] F. J. Bates, Bul. BS 2, 239 (1906) S34.
7] J. F. Brewster, J. Research NBS 16, 349 (1936) RP878.
8] J. F. Brewster, Facts About Sugar 28, 228 (1933) (abstract.)
9] K. S. º J. Research NBS 14, 543 (1936) RP785; J. Opt. Soc. Am. 25,
131 (1935).
[20] C. Pulfrich, Z. Instrumentenk. 26, (1929).
[21] Pulfrich Photometer, Advertising booklet. (Carl Zeiss, Inc., 485 Fifth Ave.,
New York, N. Y.)
[22] E. Landt, Z. Ver. deut. Zucker-Ind. 84, 954 (1934).
[23] R. Müller, Ind. Eng. Chem., Anal. Ed. 11, 1 (1939).
[24] K. S. Gibson, NBS Letter Circular LC 473 (1936).
[25] K. Sandera, Z. Zucker-Ind. Čechoslovak. Rep. 31, 261 (1927–28).
[26] P. Jackuschoff, Deut. Zucker-Ind. 56, 859 (1931).
[27] A. L. Holven and T. R. Gillett, Facts About Sugar 30, 169 (1935).
[28] J. C. Keane and B. A. Brice, Ind. Eng. Chem., Anal. Ed. 9, 258 (1937).
[29] E. Landt and H. Z. Hirschmüller, Z. Wirtschaftsgruppe Zucker-Ind. 87, 449
(1937).
[30] Th. Herke and N. Rempel, Deut. Zucker-Ind. 59, 379, 397 (1934).
[31] Brukner and Becker, Deut. Zuckerind. 59, 692 (1934).
[32] A. R. Nees, Ind. Eng. Chem., Anal. Ed. 11, 142 (1939).
[33] B. Lange, Z. Instrumentenk. 53, 344, 379 (1933).
34] H. Hirschmüller, Dessertation, Univ. Berlin, June 10, 1938.
[35] B. Lange, Photoelemente und ihre Auwendung (J. A. Barth, Leipzig, 1936).
[36] H. Krefft and E. Summerer, Das Licht 4, 1, 23, 86, 105 (1934).
[37] K. S. Gibson, J. Opt. Soc. Am. 2, 23 (1919).
[38] R. B. Withrow, C. L. Shrewsbury, and H. R. Kraybill, Ind. Eng. Chem.,
Anal. Ed. 8, 214 (1936).
[39]. J. F. Brewster and F. P. Phelps, Ind. Eng. Chem., Anal. Ed. 2, 373 (1930).
[40] H. H. Peters and F. P. Phelps, Tech. Pap. BS 21, 271 (1927) T338.
Polarimetry, Saccharimetry, and the Sugars 341
[41] Jena Fritted Glass Filters, Advertising booklet, Fisch-Schurman Corpora-
tion, 230 E. 45th St., New York, N. Y.
[42] J. F. Brewster and F. P. Phelps, BS J. Research 10, 365 (1933) RP536.
[43] T. Tadokoro, J. Chem. Ind., Japan, 21, 405 (1918).
[44] M. T. Sanders, Chem. Met. Eng. 28, 541 (1923).
[45] M. T. Sanders, Ind. Eng. Chem. 15, 781 (1923).
[46] M. T. Sanders, Ind. Eng. Chem. 15, 785 (1923).
[47] M. T. Sanders, Ind. Eng. Chem. 20, 791 (1928).
[48] J. E. Teeple and P. Mohler, Ind. Eng. Chem. 16, 498 (1924).
[49] A. A. Blowski and J. H. Bon, Ind. Eng. Chem. 18, 32 (1926).
[50] J. Dedek, Sugar 29, 255, 307 (1927).
[51] H. Freundlich, Z. physik. Chem., 57, 385 (1907).
[52]. H. Freundlich, Kapillarchemie, p. 232 (Akadem. Verlags Ges. M. B. H.
Leipzig, 1922). English translation by H. S. Hatfield, Colloid and Capil-
lary Chemistry (Mathuen & Co., Ltd., London).
[53] T. B. Wayne, Ind. Eng. Chem. 20, 933 (1928).
[54] H. I. Knowles, Ind. Eng. Chem. 19, 222 (1927).
[55] G. L. Spencer, Handbook for Cane Sugar Manufacturers and Their Chemists,
{; º Revised by G. P. Meade (John Wiley & Sons, New York, N. Y.,
1929). -
[56] D. B. Judd and K. S. Gibson, J. Research, NBS 16, 261 (1936).
[57] R. T. Balch, Ind. Eng. Chem., Anal. Ed. 3, 124 (1931).
[58] F. W. Zerban and L. Sattler, Ind. Eng. Chem., Anal. Ed. 8, 168 (1936).
[59] V. Mastalir, Z. Zuckerind. Čechoslovak. Rep. 56, 337 (1931–32).
[60] P. § and W. Thomson, Mededeel. Proefsta. Java-Suikerind vol. 38, p. 1417
1930).
[61] L. A. Wills, Facts About Sugar 21, 1114 (1926).
[62] O. Spengler and E. von Heyden, Z. Ver. deut. Zucker-Ind. 81, 693 (1931).
XX. MEASUREMENT OF TURBIDITY
1. METHOD OF BALCH
The method proposed by Balch [1] for the measurement of turbidity
in sugar products is based upon the principle of measuring the trans-
mittancy of light through the turbid solution, matched against a portion
of the same solution from which turbidity-causing material has been
removed by filtration. The color of the turbid solution is thus com-
pensated by the filtered portion.
The procedure described here is taken mainly from Balch’s article.
The instrument used was a Keuffel & Esser spectrophotometer, all
measurements being made at wave length 560 mp.
Juices and many factory sirups may be filtered without dilution.
In the case of high-density or solid products, a density greater than
60 percent of solids is not recommended. A 100- to 200-g portion of
the turbid sugar solution to be tested is filtered with 2 to 10 percent
of kieselguhr (based on sugar solids). The quantity of filter aid to be
used depends upon the quantity and character of the suspended
material affecting filtration. After mixing the kieselguhr very
thoroughly with the sample, it is filtered at room temperature under
diminished pressure through paper in a Büchner funnel which may be
attached to a fractional distillation receiver whereby containers may
be changed without breaking the vacuum. The filter apparatus of
Zerban and Sattler (fig. 77, p. 328) serves the same purpose. After
25 to 50 ml of the solution has filtered, the remainder is received in a
clean container. This last portion should appear brilliantly clear by
transmitted light.
The turbid untreated portion of the solution is freed from coarse
suspended material by straining through 200-mesh bolting silk, and
freed from air bubbles by subjecting the sample to vacuum, con-
342 Circular of the National Bureau of Standards
veniently in the fractional distillation receiver at the time of filtration.
The percentage of solids is determined with a refractometer.
In one of a matched pair of absorption cells is placed a portion of
the clarified solution and in the other a portion of the strained and
bubble-free turbid solution. The choice of thickness of the absorbing
layer to be chosen depends upon the depth of color and turbidity of
the solutions. For white sugars, cells 10 cm long or longer are needed,
while for raw sugars a thickness of 1 cm or less is sufficient. The
cells are mounted on the spectrophotometer and the transmittancy
readings are taken in the usual manner. The accepted transmittancy
value (the average of a number of readings) is then reduced by means
of the Lambert–Beer formula to the specific absorptive index,
1
Since the color of the turbid solution is compensated by that of the
clarified solution, —log tº is taken to represent the turbidity. By
replacing the turbid solution in its absorption cell with distilled water,
the transmittancy of the filtered solution may now be measured and
calculated to —log tito give a measure of color.
Since, in the Balch method, the turbidity value is taken as the
difference in —log tof a filtered and an unfiltered solution, this value
may be similarly obtained with any instrument capable of yielding
transmittancy readings at the same wave length. For instruments of
the Duboscq type, as previously described (p. 315), where thickness
of the absorbing layer is the quantity observed, reliance cannot be
placed upon direct matching with a standard, as in filtered solutions,
because of the uncertainty of the Lambert law applying to turbid solu-
tions. A procedure may be used with the Duboscq wherein – log T
for 1-cm thickness of the filtered solution is first found as prescribed,
and the latter is then matched against the turbid solution, which is
held at fixed thickness. This may perhaps be made more clear by the
following example.
The solution (washed raw sugar) was filtered through a loose plug of
absorbent cotton and a portion was filtered with asbestos. The
absorption of the glass standard, –log T, at 560 mp was 0.31069, and
the thickness of the filtered solution at match was 1.821 cm. Then
—log T for b- 1 cm is 0.31069/1.821 = 0.17062. After replacing the
filtered solution in one cup with turbid solution, the thickness of the
latter in the colorimeter was set at 1 cm, and an intensity match was
obtained by adjusting the filtered solution, no standard plate being
used. The observed average thickness found was 3.313 cm. Deduct-
ing 1 cm, allowance for ordinary absorption in the turbid solution, we
have 2.313 cm. Multiplying by — log T for b- 1 cm in the filtered
solution, we have 2.313× 0.17062=0.39464, the value to be called
—log T for a thickness of 1 cm in the turbid solution. The values for
—log tº are then calculated in the manner prescribed.
2. METHODS EMPLOYING THE ZEISS NEPHELOMETER
(a) DESCRIPTION OF THE APPARATUS
An early design of the Zeiss nephelometer was described by Sauer
[2]. The following is a description of a later model, and a diagram
of the instrument is shown in figure 81. A more detailed description
is to be found in the Zeiss advertising pamphlet [11]:
Polarimetry, Saccharimetry, and the Sugars 343
The apparatus consists of two parts, a Pulfrich photometer in the
horizontal position, as shown at the left of the diagram, and a means
of producing a Tyndall beam, shown in the circular housing at the
right. The cell containing the test liquid is placed in the cylindrical
chamber, which contains distilled water. Light from the 8-volt 50-
candlepower lamp enters the chamber through a lens as a parallel
pencil of square cross section. The light scattered by illuminated
particles leaves the chamber through a second lens and enters the
left aperture of the photometer in a direction 45° from the direction
of incidence. Part of the light from the source is reflected by an
inclined glass plate located between the source and the entrance lens,
and serves to illuminate an opal or ground-glass diffusing disk which
provides a turbidity standard for comparison. Four disks, giving
Chamber with
distilled wator Beaker with
~ turbid solution
Source
of light
ºlº sº....
Drumhead Comparison Unit of
Brightness
Zeiss-Pulfrich photometer with arrangements for turbidity measure-
ºnent.
FIGURE 81.
different intensities of diffuse light, are mounted in a revolving carrier
and are readily interchanged. A translucent glass body with invari-
able degree of turbidity is provided which may be introduced in the
water chamber in place of the sample. This body is calibrated in
terms of the incident light and is used for calibrating the instrument
and for determining turbidity in absolute terms. In case fluorescing
substances are being examined, a red glass is provided to absorb fluo-
rescence-producing radiation from the source. The vessels for contain-
ing the test solution consist of a 2.5-mm flat cell of 1-ml capacity and
two cylindrical beakers 26 and 36 mm in diameter, respectively, with
respective capacity of 10 and 25 ml. Color filters are provided which
may be placed in the revolving filter holder of the photometer eye-
piece. The green filter is most frequently used because of higher
visibility of the transmitted light.
To make an observation, the cell containing the test solution
is placed in the water chamber and the corresponding photometer
drum set at a reading of 100. One of the standard glass disks is
brought into position by rotating the holder; the eyepiece filter is
also brought into the field of view. The observer then adjusts the
photometer drum corresponding to the position of the turbidity
standard (the brightness of the standard should always be greater than
that of the sample) until a photometric match is obtained. The




344 Circular of the National Bureau of Standards
reading of this drum is then in terms of percentage of brightness
of the standard. The mean of several readings thus obtained is
called the relative turbidity. The calibrated turbid body is now
substituted in the water chamber for the sample and in turn matched
with the standard disk. The turbidity of the sample in absolute
measure follows from the ratio of the two sets of measurements.
Sauer in a second article [3] published a theoretical study of light
scattering in which were considered various factors, including the
influence of absorption, thickness of layer, direction of observation
in relation to direction of illumination, determination of the scattering
function from observations, the calibration of turbidity standards, etc.
For the Zeiss-Pulfrich turbidimeter, in which the angle of incidence
; 0 and the angle of observation is 45°, Sauer gives for the intensity
actor
9 -
/ &ºf e-ka[1 ------ e-ka(V3–1)],
V5–1
where k is the extinction coefficient (absorbancy) for unit length, d
is the thickness of the layer bounded by the parallel surfaces of the
plane parallel cell, and e is the base of natural logarithms. Expressed
in figures
J’=4.83e-º" (1 — e-kd 0.414).
At low concentrations, in turbid media with extinction coefficient
up to 0.01, the effects of multiple scattering are not noticeable. With
increasing concentration, multiple scattering or reflection brings
about an increasing brightness. Upon reaching a critical concentra-
tion the contribution of multiple scattering becomes considerable
and finally outweighs the primary scattering by many times. Within
the region of concentration wherein multiple scattering causes no
noticeable effect, the variation of the observations from the pro-
portionality with ka necessary for calculation may be adjusted by
multiplying the observed scattering intensity by the correction factor,
f(k). This factor, in the case of observations with the plane parallel
cell, may be expressed by the following formula:
0.414kd
e-ka (1 --- e-041aka) e
f(k) =
The observations are carried out as already described, the Tyndall
beam intensity of the sample being compared with that of the arbitrar-
ily chosen milk-glass plate to obtain the relative turbidity. The
calibrated standard with turbidity, t, is substituted for the sample,
and its brightness, H, measured against the arbitrary standard.
The turbidity, T, or absolute turbidity, is found by the formula
T= relative turbiditydi.
H
The factor, d, is equal to the reciprocal relation of the depth of layer
in the sample cell to that of the turbid standard. As already ex-
plained, t is the absolute turbidity of the glass turbidity standard.
Polarimetry, Saccharimetry, and the Sugars 345
(b) PROCEDURE OF ZERBAN, SATTLER, AND LORGE
Zerban and Sattler [4, 5, 6, 7, 8, and Zerban, Sattler, and Lorge
[9], using the Zeiss-Pulfrich turbidimeter, studied the turbidity of
Solutions containing coloring matter (caramel) and turbidity (sus-
pended bentonite or Filter-Cel) varied in known proportions. This
study was extended to include solutions of raw cane and white re-
fined sugars, one of the objects being to determine both color and
turbidity in the turbid solution without filtration.
In preparing the solutions, it is considered imperative that a uniform
system be adopted, since a large number of factors can disturb both
the color and turbidity values of a given sample. The following
procedure is used [4]:
The sugar is weighed in a wide-mouthed Erlenmeyer flask, and
enough boiling-hot distilled water is added on the balance to bring
the solution slightly above 60 Brix. The flask is placed in a beaker
of water at 80°C and the contents is stirred gently. After the sugar
is in solution, it is cooled quickly to room temperature and whirled
for 15 minutes in a small hand centrifuge at 1,100 rpm to remove
coarse material. Finally the density is adjusted to 60 Brix with a
refractometer. For dark products the same glass cells are used for
measuring both transmittancy and Tyndall-beam intensity, the
reference standard for the latter being the turbid glass block, which
is calibrated by the manufacturers. After the cells are filled, the
optical surfaces are cleaned and polished, and meticulous care is
exercised in all manipulations. For nearly colorless solutions the
transmittancy must be read in much longer cells, affording thick-
nesses of 10 to 20 cm. The values of —log T may then be reduced
to 1 cm or any other desired thickness. Likewise, for low tur-
bidities, the cylindrical cells (26 or 36 mm in diameter) available
with the instrument are used.
To find the concentration of turbidity, N, and the concentration
of coloring matter, C, from the instrument readings (—log T for ab-
sorbency, and R for the relative turbidity) two formulas are given [8]:
N_Rºº (90)
C= (–log T)—N (91)
Combining eq 90 and 91, we have
C= (–log T) Rºº, (92)
both N and C being expressed as —log T. f(C) is a correction fac-
tor replacing f(k) in the formula of Sauer, f(C) being a function of color
alone, whereas f(k) of the Sauer formula is a function of both color
and turbidity. The correction factor then becomes
|(-log T) "ºlº-p X2.30259
Tººl, Tºjº
f(C)= (93)
Although there remains some uncertainty about the true value of
constant a, the value found experimentally by the authors (log a
for the green filter=3.77551) is accepted for the present.
346 Circular of the National Bureau of Standards
To calculate C and N from R and —log T, eq. 93 is solved for varying
values of C, which is the (-log T)—Rf(C)/a term, and a tabulation
of corresponding f(C) values is thus obtained. The substitution of
these C and f(C) values at specified increments of R in eq 93 yields a
table from which C may be found for any pair of —log T and R values.
Practically, C is found from curves based on the table, and N is
obtained by subtraction from —log T. A graph covering the entire
range of C, -log T, and R values of raw sugar is shown in figure 82.
º
ſ
O
More exact results may be obtained if interpolation for R is carried
out by means of table 41 on the basis of the approximate value of
C read from the graph. The use of the table is explained by the
following example:
A raw-sugar sample gave —log T-0.57807, and R=917.1 for the
green filter. On the graph, C is found to lie between 0.25 and 0.30.
The value of RfC)/a for 1 R at C-0.25 is 0.0003351; hence that for
917. 1 R is 0.0003351×917.1 = 0.30732, which, added to 0.25 c, gives

Polarimetry, Saccharimetry, and the Sugars 347
—log T=0.55732. Similarly the value of RfC)/a for 1 R at C-0.30,
is 0.0003847, and that for R=917.1 is 0.35280, which, added to 0.30,
gives —log T-0.65280. The difference, ar, between the required
value of C and the value 0.25 is found from the equation
(2–0.25): (0.30—0.25)=(0.57807–0.55732): (0.65280–0.55732).
The result for a is 0.0109, which, added to 0.25, gives a value of 0.2609
for C. N equals 0.57807–0.2609, or 0.3172.
TABLE 41.- Zerban and Sattler table for finding C and f(C) from – log T and Jº
Rſ(C) Rſ(C) |
“y y (I y f (l
C f(C) for C ſ((') for
R–1 R= 1
(). 0000 1. ()00() (). ()001677 (). 1000 1. 3200 (). ()()02213
. 0010 1. ()027 . 0001681 . 1500 1. 1500 . ()002542
, 0.020 1. 0.055 . ()001686 . 2000 1. 7406 . ()002919
. 0.030 1. ()083 . ()001691 . 2500 1. 9986 . 000335||
, ()()40 1. ()11() . ()001695 . 3000 2. 2941 . ()003847
. ()05() 1. ()138 . ()001700 . 3500 2, 6331 . ()004415
. ()060 1. ()166 . ()001705 . 4000 3. 0214 . 0005066
. ()070 1. ()194 . ()001709 . 4500 3. 4664 . 0005813
. 0080 1. 0.222 . 0001714 . 5000 3.9757 .0006667
. 0090 1.0250 . ()001719 . 5500 4. 5598 . 0007646
. 0100 1.0278 . 0001723 . 6000 5. 2281 . 0008767
. 0110 1. 0306 . 0001728 . 6500 5.993.7 . 0010050
. 0120 1.0335 . 0001733 . 7000 6. 8699 . 0011520
. ()130 1. 0363 . 0001738 . 7500 7, 8727 . 0013201
. 0140 1.0391 . 0001742 . 8000 9, 0.199 . 00151.25
. 0.150 1. 0420 . 0001747 . 8500 10. 3329 " . 0017327
. 0}60 1,0448 . 0001752 . 9000 11. 8342 . 0019844
, 0.170 1. 0477 . 0001757 . 9500 13. 5520 . 0022724
. 0180 1.0506 . 0001762 1.0000 15. 5154 . 0026017
. ()190 1. 0535 . OOO1767 1. 0500 17. 7609 . 0029782
. 0200 1.0564 . 0001771 1. 1000 20, 3270 . 0034085
. 0220 1. 0622 . 0001781 1. 1500 23. 2604 . 0039004
. 0240 1. 0680 . 0001791 1, 2000 26. 6117 . 004.4623
. 0260 1.0739 . 0001801 1. 2500 30. 4415 . 0051045
. 0280 1.0798 . 0001811 1. 3000 34. 8136 . 0.058376
. ()300 1.0862 . 0001821 1. 3500 39, 8110 . OO66756
. 0350 1. 1023 . 0001848 1. 4000 45. 5150 . 0076321
. 0400 1. 1175 . 0001874 1. 4500 52. 0280 . 0087242
. 0450 1. 1332 . 0001900 1. 5000 59. 4610 , 0099706
. 0500 1. 1488 . 0001926 1. 5500 67.9469 . 0113936
. 0550 1, 1647 . 0001953 1. 6000 77. 6286 . 01:30170
. 0600 1. 1814 . 0001981 1. 6500 88. 6764 . 0.1486.96
. 0650 1, 1978 . 0002008 1. 7000 101. 1057 . 0169537
. 0700 1. 2146 . 0002037 1. 7500 115. 6513 .0193928
. 0750 1. 2316 . 0002065 1. 8000 132.0390 . 0221,408
. 0800 1. 2491 . 0002095 1, 8500 150. 7322 . 0252753
. 0850 1. 2661 . 0002123 1. 9000 172. 0380 . 02884.79
. 0900 1.2838 . 0002153 1.9500 196. 3277 . 0329.209
. 0950 1. 3017 . 0002183 2, 0000 224.0030 . 0375616
The absolute turbidity can also be calculated by means of table 41
and the Sauer equation
S=Af(k) Dt,
where S is the absolute turbidity, A is the relative Tyndall beam-
intensity as measured with the turbidimeter and equals 0.01 R in the
Zerban and Sattler system. D is a factor varying with the thickness
of the absorption cell, and t is the absolute turbidity of the standard
glass block. By interpolation of column 2 in this table, the f(C) for
C(kd) equal to 0.2609 is found to be 2.0630. By substituting this
figure in eq 90 along with A(0.01 R)=9.171, D=6.6395 (for the
348 Circular of the National Bureau of Standards
2.455-mm cells used) and t=0.00282, the absolute turbidity found is
0.3542.
For products which are low in both color and turbidity the graph
shown in figure 83 is used. If the scale is such that C and —log T are
;à;:;;
:
;
:
;:
º
::
#
#
:
:
plotted at 50 mm =0.001 unit, it is possible to read C and -log T
values accurately to the fourth decimal place.
Values of —log T and of R, determined at one thickness, may be
converted into corresponding values at another thickness, or -log
T into —log t. Over a wide range of thickness, the absorbancy is
not directly proportional to the depth, b, in the turbid solutions, but
is a power function of it, according to the equation
—log Ti: —log T2+ (b1:bg)”.

Polarimetry, Saccharimetry, and the Sugars 349
(c) PROCEDURE OF LANDT AND WITTE
Landt and Witte [10], employing a Zeiss-Pulfrich turbidimeter,
studied the turbidity in 45-Brix sugar solutions which had been filtered
through paper. Only the practical application of their method is given
€I'ê.
The procedure in making measurements is similar to that of Sauer
[3], as described above, in that the turbid solution is first compared in
brightness with an arbitrary glass turbidity standard to give the rela-
tive turbidity. From this value is deducted the turbidity value of the
water surrounding the sample cell, giving a value called the corrected
relative turbidity. This value is divided by the brightness of the cali-
brated turbidity standard, H., of the instrument relative to the turbid-
ity brightness of the arbitrary standard used, thus giving the value A,
or A= corr. rel. turb./H. The value A is next multiplied by f(k),
which, according to Landt and Witte, is found by the Sauer for-
mula, applying only to the plane parallel cells:
f(k) = kd(V2–1)2.303
- 10-ka-Fm+n)|T10-ka(V3-)] (94)
Here k is a factor depending upon the extinction coefficient and d is
the thickness of layer. For cylindrical beakers, account is taken of
the fact that the primary as well as the scattered light suffers a weaken-
ing in passage through layers of solution on two sides of the actual
Tyndall pencil. These factors are designated, respectively, m and n,
and formula 94 becomes for the 26- and 36-mm beakers:
tº ºvº-D2.80%
10-k(d+m+n) [1–10-ka(V3–1)]
(95)
Values of k and f (k), as calculated for various sizes of plane parallel
cells are given in table 42, and for the 26-mm and 36-mm beakers, in
table 43.
TABLE 42.-Values of k and f(k) for plane parallel cells of various thicknesses
(Landt and Witte)

Values of k Values of k
for cell thickness, mm for cell thickness, mm
f(k) f(k)
1.00 2.50 5.00 10.00 1.00 2.50 5.00 10.00
0.10 0.04 || 0.02 || 0.01 1. 030 1. 50 0. 60 || 0.30 || 0, 15 | 1. 514
. . 20 . 08 . 04 . 02 1. 061 2. 00 80 . 40 . 20 1. 731
. 30 . 12 . 06 . 03 1. 087 3.00 1. 20 . 60 . 30 2. 335
. 40 . 16 . 08 . ()4 1. 120 4. 00 1. 60 - 80 . 40 3. 020
. 50 . 20 . 10 . 05 1. 149 5. 00 2. 00 1. 00 . 50 3. 970
. 60 . 24 . 12 . ()6 1. 181 6. 00 2. 40 1. 20 . 60 5. 220
. 70 . 28 . 14 . 07 1. 216 7.00 2.80 1. 40 . 70 6. 870
. 80 . 32 . 16 . 08 1. 250 8.00 3. 20 1. 60 . 80 9. 020
. 90 . 36 . 18 . 09 1. 284 9. 00 3. 60 1.80 . 90 11. 830
1. 00 . 40 . 20 ... 10 1. 319 10, 00 4. 00 2. 00 1. O0 15. 190
323414°—42—24
350 Circular of the National Bureau of Standards
TABLE 43.− Values of k and f(k) for cylindrical beakers 26 mm and 36 mm in
diameter (Landi and Witte)
f(k) for diameter f(k) for diameter
k k
26 mm 36 mm 26 mm 36 mm
0 0004 1. 002 1. 003 0, 0217 1. 133 1. 172
. 0022 1. 013 1. 016 . 0.261 1. 162 1. 210
. 0043 1. 026 1. 033 . 0304 1. 191 1. 250
. 0087 1. 051 1. 066 . 0347 1. 222 1. 290
. 01:30 1. 078 1. 100 . 0391 1. 252 1. 332
. 0174 1. 105 1. 136 . 0434 1. 284 1. 375
Next, in order to obtain strict comparison with other plane parallel
cells or for calculation to absolute turbidity Af(k) must be multiplied
by the factor, D, which is the ratio of the layer thickness of the cali-
brated standard to the layer thickness of the plane parallel cell.
Finally, to reduce the results to terms of absolute turbidity, the whole
is multiplied by t, the turbidity of the calibrated standard. The
formula is therefore:
Absolute turbidity, T=Af(k) Dł.
3. REFERENCES
. T. Balch, Ind. Eng. Chem., Anal. Ed. 3, 124 (1931).
. Sauer, Z. Instrumentenk. 51, 408 (1931).
. Sauer, Z. tech. Physik. 12, 148 (1931).
W. Zerban and L. Sattler, Ind. Eng. Chem., Anal. Ed. 3, 326 (1931).
W. Zerban and L. Sattler, Ind. Eng. Chem., Anal. Ed. 7, 157 (1935).
W. Zerban and L. Sattler, Ind. Eng., Chem., Anal. Ed. 8, 168 (1936).
W. Zerban and L. Sattler, Ind. Eng. Chem., Anal. Fol. 9, 229 (1937).
W. Zerban and L. Sattler, Ind. Eng. Chem., Anal. Ed. 10, 9 (1939).
dº Zerban, L. Sattler and I. I.orge, Ind. Eng. Chem., Anal. Ed. 6, 178
1934).
[10] E. Landt and H. Witte, Z. Ver. deut. Zucker-Ind. 84, 450 (1934).
[11] Zeiss Nephelometer, Advertising booklet (Carl Zeiss, Inc., 485 Fifth Ave.,
New York, N.Y.) *
XXI. VISCOSITY OF SUGAR SOLUTIONS
1. THEORETICAL
Wiscosity is the property of homogeneous fluids that causes them
to offer resistance to flow. It is expressed mathematically by the
constant of proportionality between shearing stress and rate of shear.
It has the dimensional formula MLT'T', and is generally expressed
as m. In the cgs system, the unit of viscosity is the poise. The one-
hundredth part of this unit (the centipoise) is frequently used in prac-
tice. The viscosity of water at 20° C is often taken as 1.005 centi-
poises. The ratio of viscosity to density is called the kinematic
viscosity, and the cgs unit is called the stoke, poises/(g/cm3). The
reciprocal of viscosity is fluidity. The cgs unit of fluidity is the rhe.
An extensive investigation of the flow in capillary tubes was first
undertaken by Poiseuille about 1838. He found that the rate of dis-
charge was directly proportional to the first power of the pressure
difference and to the fourth power of the diameter and inversely
proportional to the length of the capillary tubes. This relationship,
which is known as Poiseuille's law, expressed mathematically, is
Polarimetry, Saccharimetry, and the Sugars 351
V ºr ApHº
T & LT’ (96)
where
m=Viscosity, in poises,
V=cm” discharge in t (seconds),
Ap=difference in pressure between the two ends of the tube
(dynes/cubic centimeter),
L=length of the tube in centimeters,
R= radius of the tube in centimeters.
This formula may be derived, assuming a capillary tube of uniform
diameter and sufficiently long that kinetic energy and end effects are
negligible. Consider a cylindrical volume element of the fluid of
length dB, radius r, and with the difference in pressure dp between
the ends. The resultant force tending to push this volume element
downstream is Trºdp. This force is resisted by the shearing stresses
due to viscosity, assuming the fluid adheres to the walls of the tube.
Let S denote the shearing stress at radius r, i. e., the tangential force
per unit area exerted upon the cylindrical surface, 27tral L, by the fluid
between it and the wall of the tube. The total shearing force acting
upstream is 2TrSdL. Under steady flow conditions (no acceleration),
these two forces must be equal, so that
2TrSal L=trºdp. (97)
When conditions are uniform throughout the length of the tube,
p
S= 3IAp. (98)
Let v denote the velocity at radius r. The velocity gradient with
respect to increasing values of r is —dv/dr, where do is the difference
in velocities at the radial distances r and r–H dr from the axis of the
tube. The definition of viscosity, m, expressed mathematically, is
do
S= — "I,... (99)
Combining eq98 and 99 gives
, Ap.
dv- 2 #dr. (100)
The volume of fluid flowing per unit time is trrºdy, and, integrating
over the entire tube, using eq 100, gives
V_TRAp
ºf TSLn. ' (101)
which is the usual form of Poiseuille's law. It also may be written
_TRºtAp_
m=-sily = Otap, (102)
where C= TR*/8LV is a constant for a given capillary viscometer.
Where the liquid of density, p, flows by gravity with an effective
352 Circular of the National Bureau of Standards
hydrostatic head, h, so that Aq) = phſ, eq 102 gives for the ratio of
viscosities of two liquids
mi_phiti.
772 phot, (103)
Equations 102 and 103 have been accurately verified experimentally
for long capillaries with small rates of flow. The results of measure-
ments over a convenient range of rates of flow with many types of
capillary viscometers have been found [1,2, 3] to be represented, within
experimental errors, by the relation
n=Atap-º. (104)
where A and B are instrumental constants for a particular viscometer
and direction of flow. The constant B has been found to be approxi-
mately equal to V/8TL (using cgs units in eq 104), but it should be
determined by experiment.
2. CAPILLARY - TUBE VISCOMETERS
(a) OSTWALD VISCOMETER
The Ostwald viscometer (fig. 84–I) is one of the earliest forms. It
consists of a glass U-shaped tube, one limb of which contains a smaller
bulb discharging into a capillary tube, while the other contains a
tube of larger diameter with a larger bulb near the bottom. There
are no standard dimensions for this instrument, and since the hydro-
static head causing flow cannot be varied, any considerable change in
viscosities must usually be covered by the use of a series of instruments
with capillaries of different sizes. With the usual type of Ostwald
viscometer, a certain volume of liquid is introduced into the wider
limb, frequently by means of a pipette, and drawn up through the
capillary to a mark above the smaller bulb. In making a measure-
ment with all Ostwald instruments, the liquid is forced through the
capillary tube to a mark above the upper bulb, and the time required
for the meniscus to fall by gravity from the upper mark, C, to another
mark, D, below the bulb, is measured.
(b) BINGHAM VISCOMETER
The Bingham viscometer (fig. 84–II) is a refinement of the Ostwald
capillary tube type. An advantage is the small sample required, 4
ml being a common capacity of the bulb, C, which is emptied or filled
during a measured time interval. There are no standard dimensions,
the range of viscosities to be measured determining the size of capil-
lary chosen. Any one instrument can be used to measure a wide
range of viscosities, since various pressures may be used. The average
hydrostatic head may be made negligible, the liquid being forced
through the capillary by air pressure, which is kept as constant as
possible during a measurement. A trap makes it possible to take
readings at increasing temperatures without refilling. The working
volume of liquid is from A to H or from E to M. Drainage errors
may be avoided by forcing the liquid through the capillary into a
dry bulb, in which case the time required for the meniscus to pass
from D to B is measured.
Polarimetry, Saccharimetry, and the Sugars 353
(c) UBBELHODE VISCOMETER
The Ubbelhode viscometer (fig. 84–III) is a “suspended level”
instrument [5]. It consists essentially of three glass bulbs connected
by suitable tubes, one of which is a capillary. The pipette, A–D,
provided with graduations at M1 and M2, connects through the capil-
lary, 4, with the 12-mm bulb, C. The bulb, C, is connected with bulb,
B, and to the atmosphere through tube 3. Bulbs A and B are con-
nected to the atmosphere through tube 2 and the larger filling tube,
1, respectively.
In operation, bulb B is filled with the liquid in question through
tube 1 until the meniscus lies between the marks X and Y. Tube 3
1 2 3
P- | fi - K-
C
M1
A
D — NºM2
A
M A.
B
D
E HH
FIGURE 84.—Viscometers.
I, Ostwałd; II, Bingham; III, Ubbelhode.
is closed at the top, and suction is applied to tube 2 until the liquid
is drawn above the mark M1. Tubes 2 and 3 are now opened to the
atmosphere, thereby dividing the liquid in C into two parts and pro-
ducing the “suspended level” at the lower end of capillary 4. Simul-
taneously with the formation of the suspended level, the liquid
begins to flow in a thin layer on the vertical walls of C into B. The
observer determines the interval of time required for the meniscus
to drop from Mi to M2.
3. SHORT-TUBE VISCOMETERS
There are a number of short-tube efflux viscometers, such as the
Saybolt (United States), Redwood (Great Britain), and Engler
(Germany), sufficiently alike to be considered as a group. These

354 Circular of the National Bureau of Standards
instruments have been widely used in the petroleum industry. The
dimensions of each instrument and the methods of operation have been
standardized in different countries. They are sturdy, since they are
constructed almost entirely of metal, and are easily manipulated. The
instruments are portable and require no elaborate installation other
than provision for heating the bath. The operation of each instrument
is essentially the same. The liquid to be examined is poured into an
open cup or tube, in the base of which is a short capillary provided
with a simple form of valve. The level of the liquid in the cup is
adjusted to a definite height, the valve is opened, and an observation
is made of the time required for a definite volume to be discharged
through the air into a measuring vessel placed below the capillary.
4. FALLING-BALL VISCOMETERS
Viscosity may also be measured by determining the velocity with
which a sphere of known radius falls in a viscous medium. The rela-
tion between the viscosity; density of the liquid, p; density of the
sphere, po; velocity of the sphere, V; and radius of the sphere, R,
according to Stokes' Law, is
2 (o, - 2
m = ºpuſ ſº (105)
In this equation the velocity of the sphere is assumed to be constant,
and no consideration is given to effects of the walls and ends of the
vessel. Experimental evidence [3] indicates that corrections for such
effects are practically independent of the viscosity, so that for a given
tube and sphere which falls the same distance in times t1 and to in
two different liquids, 1 and 2, the ratio of the viscosity is given by
71 (po-pi) ti - *
–––. - –—— — e 106
7)2 (po-p2) tº ( )
(a) HOEPPLER VISCOMETER
The Hoeppler viscometer is a modification of the falling-ball type.
It consists of a glass tube of uniform internal diameter mounted at a
10° angle from the vertical, through which a ball is allowed to roll.
Balls of different sizes are available, so that this instrument is applic-
able to a large range of viscosities (0.6 to 75,000 centipoises). Mea-
surements of the time required for a ball to pass between the two
marks on the glass tube when it is filled with different liquids permit
an evaluation of viscosity by means of eq 106.
5. ROTATIONAL VISCOMETERS
The resistance which a liquid offers to a rotating body may also
be used to measure the viscosity of that liquid. The MacMichael
and Stormer viscometers, which have been used largely with liquids
having viscosities greater than about 1 poise, belong to this type
of instrument.
(a) MacMICHAEL VISCOMETER
The MacMichael viscometer [6] consists essentially, of a motor-
driven cup in which the bob of a torsional pendulum is suspended.
When the cup is rotated at a constant speed the pendulum is deflected
Polarimetry, Saccharimetry, and the Sugars 355
until the viscous drag of the liquid is balanced by the resistance of the
suspended wire to twisting. When the pendulum has come to rest a
reading may be made. Each instrument is supplied with a number of
wires of different sizes, so that a wide range of viscosities may be
determined with this instrument. The pendulum is provided with a
graduated disk divided into 300 equal parts called MacMichael de-
grees. Viscosity in poises may be calculated by the following formula:
Mo
m= K IIN’ (107)
where K=instrument constant,
M*=deflection in MacMichael degrees,
H=depth of submergence of the pendulum bob in centimeters,
N= number of revolutions per minute of the cup.
(b) STORMER VISCOMETER
The Stormer viscometer consists of a central rotor and a stationary
concentric cylinder containing the liquid whose viscosity may be deter-
mined, after suitable calibration of the instrument, from measure-
ments of the time required for completing a definite number of revolu-
tions of the rotor immersed in the sample and driven by a definite
weight.
6. CALIBRATION OF VISCOMETERS
Most of the viscometers used in routine determinations of viscosity
require careful calibration in order to obtain accurate values for
viscosity in absolute units. Such calibrations involve essentially the
determination of certain instrumental constants which appear in the
particular form of equation found to be applicable to a given type of
instrument. With capillary tube instruments, in which the average
pressure difference depends upon the average hydrostatic head, h,
and Ap=ph g in eq 102, the viscosity, in absolute units, may be
calculated from
n-Aot-º. (108)
where p is the density of the liquid in grams per cubic centimeter, t is
the time in seconds for a definite volume of flow, and A and B are
instrumental constants for a certain temperature and procedure.
Similarly, with falling-ball or rolling-ball instruments, the following
form of equation may be used:
m=C(1–p/p,)t, (109)
where p and p, are the densities in grams per cubic centimeter of the
liquid and ball, respectively; t, in seconds, is the time of fall of a
certain ball between definite marks on a given fall-tube; and C is an
instrumental constant applicable to that ball and tube for a certain
temperature and procedure. This equation permits the calculation of
viscosity in absolute units.
The above equations and analogous relations for other types of
viscometers are known to apply only to conditions called streamline
or viscous flow and are not applicable when the flow becomes turbu-
356 Circular of the National Bureau of Standards
lent. It is advisable, therefore, not to use a rate of flow in any vis-
cosity determination which exceeds the maximum employed in the
calibration of the instrument. Positive assurance of the applicability
of such equations with evaluated constants can be obtained from cali-
brations covering the entire range of viscosities to be determined.
Some instruments require Occasional recalibration to eliminate errors
caused by corrosion and other effects.
While the instrumental constants depend very largely on the
dimensions of the instrument, they may also depend to some extent
on the procedure and the physical properties of the liquids employed.
The constant A in eq 108, for example, may be somewhat different
for two liquids of widely different surface tension or viscosity, since
the actual working pressures or the volumes of flow between two works
may be different in the two instances. In measurements much
above or below room temperatures with some instruments, alterations
in procedure and differences in the heat capacity and thermal con-
ductivity of different liquids may alter the effective value of the
instrumental constants in addition to the effect of temperature on the
dimensions of the instrument.
Instrumental constants may be determined from measurements
with one or more liquids of accurately known viscosity and density.
Errors in subsequent viscosity determinations may be º
eliminated by employing for calibration purposes liquids with physical
properties not very different from the liquids to be investigated. It
is for this reason that the data on pure sucrose solutions are especially
useful in calibrating viscometers employed in the sugar industry.
Distilled water is very frequently used, but its viscosity is so low as to
be outside the practical range of some viscometers. In any case, it is
always desirable that calibrations with water be supplemented by cali-
brations with more viscous liquids. A convenient method of determin-
ing A and B in eq 108 is to plot m/pt against 1ſt” for several calibrations.
The value for A is obtained from the intercept at 1/t”=0, and B is
obtained from the slope of the best straight line representing the
Imeasurements.
One factor limiting the accuracy of calibrations is the measurement
of time. Other factors, when using sucrose solutions, are the purity
of the sucrose and the concentration of the solution. Many labora-
tories have water and sucrose of high purity available and are equipped
with balances which permit the preparation of solutions whose con-
centration in a given vessel can be accurately measured to better than
0.01 percent by weight in vacuo. Such solutions may contain a small
amount of solid particles resembling dust or lint. It is better to
make several calibrations, discarding results obviously affected by
such particles, than to resort to filtration, which may change the
initial concentration by an unknown amount. Precautions should be
taken to ensure that the initially measured concentration remains
unchanged. If the solution is not used during the day of preparation,
the vessel and contents should be reweighed and a correction applied
to the initial concentration, if necessary. Before transfer to the
viscometer, the solution should be stirred by shaking gently and
mixed with any condensate on the upper walls of the vessel. Special
care should be taken to avoid evaporation or condensation of water
during transfer and subsequent calibration measurements.
Polarimetry, Saccharimetry, and the Sugars 357
Another important factor is the control and measurement of tem-
perature. It may be noted that data on pure sucrose solutions
contained in table 130, p. 671, and recommended for use in calibra-
tions are limited to the temperature range 15° to 25° C because of
the difficulty of avoiding condensation or evaporation outside this
range of temperature. The data in table 130, together with the
accepted value for water at 20°C, permit calibrations over the range
1 to 4,000 centipoises, which should be consistent to the order of 0.1
percent or comparable to the accuracy attainable in the major factors,
namely timing, temperature, and concentration.
7. VISCOSITY OF VARIOUS SUGAR SOLUTIONS
(a) SUCROSE
Measurements of the viscosity of aqueous solutions of pure sucrose
have been reported by many experimenters. In 1917 Bingham and
Jackson [7] published measurements over the range 0° to 100°C on
solutions containing 20, 40, and 60 percent of sucrose, and reviewed
the results of several earlier observers. Landt [8] reviewed most of
the data published up to 1936 and compared his measurements with
the data of various authors on solutions containing 60 to 84 percent
of sucrose. These two articles supply a fairly complete bibliography
on the subject and indicate differences of several percent in general
between the results reported by different experimenters.
This lack of agreement, together with indirect evidence that some
of the interpolated values given by Bingham and Jackson were in
error by several percent, led to a further investigation at this Bureau.”
Wiscosity measurements were made over the range 0° to 35°C on
solutions containing 30, 40, 50, 60, 65, 70, and 75 percent by weight
in vacuum. These solutions were initially prepared with a precision
of better than 0.001 percent in the concentration, using sucrose of
very high purity. Changes in the initial concentration during the
filling of the viscometers were minimized by special precautions
described in the previous section on the calibration of viscometers.
Three instruments similar to the one described by Bingham and Jack-
son [7] were employed with capillaries of different diameters. The
instrument with the smallest capillary was calibrated with water
at 20°C, assuming the value 1.0050 centipoises. The calibrations of
the other instruments were carried out with several liquids of higher
viscosity in a step by step process. Drainage errors were elim-
inated by always flowing the liquids into a dry bulb. A separate
sample was used for each viscosity determination. At least two
measurements, usually agreeing to 0.1 percent or better, were made
at each temperature, which was adjusted to the desired integral tem-
perature (indicated by a platinum resistance thermometer) and usually
maintained constant to less than 0.01° C.
The unpublished results described above have been used as the
major basis for tables 130, 131, 132, and 133, pp. 671-75. Above 35°C,
the tabulated data are based largely on the results of Bingham and
Jackson [7], Landt [8], and Bennett and Nees [9]. Recalculation of
Landt’s data, using slightly higher values for the constants for his
falling-ball viscometers, evaluated from data on 60-percent sucrose
19 The results of this investigation will be published separately in the Bureau’s Journal of Research.
358 Circular of the National Bureau of Standards
at 20° and 30°C, leads to very satisfactory agreement between these
three groups of observers.
Jones and Stauffer [10] made some very precise viscosity measure-
ments on aqueous solutions at 25° C and obtained 5.8168 for 40-
percent sucrose and 1.9106 for 20-percent sucrose relative to water
at 25°C, which give for the ratio mao/m30=3.0445. The values given
in the tables at 25°C yield for this ratio muo/m20–5.199/1.706=3.0475,
the two ratios agreeing to 0.1 percent.
Mühlendahl [11], in a paper on sucrose solutions as calibration
liquids for viscometers, reported values for the viscosity of 60- to 66–
percent sucrose solutions, which are 10 to 20 percent lower than the
values in table 130, p. 671. His data are also reported in Landolt-
Börnstein [14]. Mühlendahl calibrated his Ostwald-type viscometer
with water over the range 14°to 30°C, assumed Poiseuille's law, and
represented the assumed single instrumental constant as a function of
temperature, which was used erroneously in the calculations of the
viscosity of sucrose solutions from the observed time of flow. Recal-
culation of his data, using the method of calibration outlined in the
previous section to obtain two instrumental constants, indicates that
his observations are consistent with the data in table 130 to the order
of 1 percent.
A critical examination of the data reported by various authors indi-
cates that most of the measurements on sucrose solutions are consistent
with the data in tables 130, 132, and 133, within reasonable uncer-
tainties in the calibrations and in the measurements of time, tempera-
ture, and concentration. It seems probable that the greatest uncer-
tainty in many instances was the concentration of the solution at the
time of the viscosity measurement.
(b) MISCELLANEOUS
International Critical Tables [15] gives a compilation of data of
various investigators on the viscosity of aqueous solutions containing
less than 50 percent by weight of pure sugars, including dextrose,
levulose, galactose, lactose, maltose, raffinose, and several mixtures
of sucrose and dextrose and also of sucrose and levulose. For a
given total concentration of sugar at a given temperature, the viscosi-
ties of all of these solutions are of the same order of magnitude as
pure sucrose solutions.
Orth [12] reported measurements from 20° to 90° C on impure
beet sugar solutions containing 60 to 80 percent of total solids which
ranged from 65 to 100% sucrose. He found that the nonsucrose present
in such solutions was equivalent, on the average, to about 0.97 of the
same weight of sucrose and that the viscosities of solutions of equal
total dry substance were approximately equal at the same temperature.
Bennett and Nees [9] reported the same approximate relationship
for various beet-sugar sirups. They found that the viscosity of
steffanized and nonsteffanized sirups with equal total dry substance
decreased approximately linearly with increased nonsucrose content.
On the other hand, the viscosity of high raffinose sirups of equal dry
substance was found to increase with the nonsucrose content.
Spengler and Landt [13] determined the influence of 14 different
inorganic salts on the viscosity of a saturated sucrose solution at 20°C.
On the addition of 2 to 10 percent by weight, nine of the salts increased
the viscosity, while the other five salts decreased the viscosity.
Polarimetry, Saccharimetry, and the Sugars 359
Viscosity is an important factor in processes of diffusion and crystal-
lization and in practical problems involving the flow of fluids. In
the design of pipe lines for handling sirups and molasses only an
approximate value of the viscosity is required. The data in tables
132 and 133, p. 673-74, may be useful in such cases if the total dry
substance is known.
8. REFERENCES
[1] E. C. Bingham, Fluidity and Plasticity (McGraw-Hill Book Co., Inc., New
York, N. Y., 1922).
[2] E. Hatschek, The Viscosity of Liquids (G. Bell & Sons, Ltd., London, 1928).
[3] G. Barr, A Monograph on Viscometry (Oxford University Press, London.
1931).
[4] Power Test Codes, Am. Soc. Mech. Engrs. Series, pt. 17 (1929).
[5] Proc. Am. Soc. Testing Materials 38, 900 (1938).
[6] Proc. Am. Soc. Testing Materials 34, 1092 (1934).
[7] E. C. Bingham and R. F. Jackson, Bul. BS 14, 59 (1917) S298.
[8] E. Landt, Z. Wirtschraftsgruppe Zuckerind. 85, 395 (1935); 86, 8 (1936).
[9] A. N. Bennett and A. R. Nees, Ind. Eng. Chem. 22, 91 (1930).
10] G. Jones and R. E. Stauffer, J. Am. Chem. Soc. 59, 1630 (1937).
11] E. V. Mühlendahl, Z. angew. Chem. 40, 1318 (1927).
12] Ph. Orth, Bul. Assn. Chim. 29, 137 (1911).
13] O. Spengler and E. Landt, Z. Ver, deut. Zucker-Ind. 80, 523 (1930).
14] Landolt-Börnstein 5, 107 (1931).
[15] Int. Critical Tables 5, 23 (1929).
XXII. SOLUBILITY OF THE COMMON SUGARS
1. SOLUEILITY OF SUCROSE IN WATER
The solubility of sucrose in pure water has been measured by a
number of investigators. Their results are not in entirely satisfactory
agreement. Sucrose in the final stages of solution or deposition from
supersaturated solution attains equilibrium very slowly, and it is
difficult to arrive at the same result from both directions, which must
be considered the criterion of accuracy. Many of the calculations of
supersaturation coefficients of industrial sirups are based on the solu-
bility of pure sucrose as determined by Herzfeld [1], whose data are
given in table 134. The solubility as determined by other workers is
given in table 135.
On the basis of Herzfeld's table of solubility of sucrose, Kukharenko
[2] has calculated the supersaturation and crystallization velocity
shown in table 136. p. 677. The table also includes data on concen-
tration, oversaturation, and hypothetical yield.
2. SOLUBILITY OF DEXTROSE IN WATER [3]
An aqueous solution of dextrose in contact with an excess of o-
dextrose crystals reaches equilibrium slowly, whether the latter is
approached from undersaturation or supersaturation. This is due not
only to the fact that, in common with many other substances, equi-
librium between crystals and solution is attained slowly, but also to
the fact that final equilibrium cannot be attained until mutarotation
of o- to 3-dextrose is complete. The final saturated solution is thus
an equilibrium between dextrose crystals and dissolved o:-dextrose
which is in equilibrium with 6-dextrose. The rates of mutarotation
of dextrose are given on page 763.
Dextrose occurs in two crystalline forms, the monohydrate and the
anhydrous. The monohydrate is the stable phase between the cryo-
360 Circular of the National Bureau of Standards
hydric point —5.3° and 50° C. Above 50° C the anhydrous form
becomes stable and remains so until, in the vicinity of 100°C, the
8-dextrose becomes stable. The anhydrous form can exist at tempera-
tures considerably below 50° C if the crystals are uncontaminated by
the hydrate. Indeed, it is possible to obtain the crystalline anhydrous
form by cooling the massecuite to below 30° C.
The solubility data are given in table 137, p. 679, and plotted in
figure 85. Curve II shows the approximate instantaneous solubilities
i
PERCENT CONCENTRATION
FIGURE 85.-The system deactrose and water.
The solid curves show the final equilibria with respect to the solid phases, ice, dextrose hydrate, and
anhydrous dextrose. The dotted curve shows the instantaneous Solubility before mutarotation. All
data are expressed in terms of anhydrous dextrose.
of cº-dextrose hydrate, in which the solid phase is in momentary
equilibrium with oſ-dextrose in solution before mutarotation to
8-dextrose has begun. This curve passes through the melting tempera-
ture of the hydrate, at which temperature the solution has the same
composition as the crystals.
3. SOLUEILITY OF LEVULOSE IN WATER
The solubility of levulose was determined at three temperatures by
Jackson, Silsbee, and Proffitt [4] as an adjunct to experiments on the
crystallization of the sugar from aqueous solution. If a parabolic
form of the solubility curve is assumed, the solubility at temperatures
intermediate between the determined points can be computed by the
formula
C=0.150103t”–0.814t–H331.023,

Polarimetry, Saccharimetry, and the Sugars 361
in which O equals the weight of levulose in 100 g of water and t is
the centigrade temperature. Such calculated points must be con-
sidered as approximations. The solubilities are given in table 138.
In order to encourage and facilitate studies on the crystallization
of levulose, an extended table of concentration and supersaturation
(table 139, p. 682) has been computed. These data are admittedly
based on insufficient experimental work and must be considered purely
tentative.
4. SOLUEILITY OF LACTOSE IN WATER
Lactose occurs in alpha and beta forms, the alpha form crystallizing
with 1 molecule of water, and the beta in the anhydrous state. The
transition temperature between the two forms is 92° to 93°C; below
this temperature the alpha hydrate separates from a supersaturated
solution, whereas the anhydrous beta form crystallizes at tempera-
tures above.
Table 140, p. 690, published by Gillis [5], contains the experimental
results of Hudson [6], Saillard [7], and Gillis [8]. The first two authors
approached the saturation point from both supersaturated and under-
Saturated solutions. Hudson determined the amount of lactose pres-
ent by evaporating the solution and drying the crystalline residue at
130° C. to constant weight. Saillard employed polariscopic and
copper-reduction methods of analysis, which he standardized by drying
the lactose on sand at 105° to 106° C. Gillis approached the satura-
tion point by increasing the temperature of a solution in the presence
of a solid phase until the disappearance of all crystals.
Hockett and Hudson [9] have found that when the alpha lactose
hydrate is shaken for 10 minutes at room temperature with 10 times
its weight of methyl alcohol containing from 2 to 5 percent of anhy-
drous hydrogen chloride, a crystalline phase separates. This is a
molecular compound having the composition 5 o'-lactose—3 3-lactose.
5. SOLUEILITY OF SUGARS IN SUGAR MIXTURES
(a) THREE-COMPONENT SYSTEMS
The system: dertrose, lepulose, and water.—When a sugar is dissolved
in an aqueous solution of another sugar, its solubility in the water of
such a solution is in general diminished as a result of the salting-out
effect of the second sugar. Thus Jackson and Silsbee [10], in a study
of the solubility of dextrose in levulose solutions, found that while
100 parts of pure water dissolved 120.5 parts of dextrose (anhydrous)
at 30°C, 100 parts of water containing 106.2 parts of levulose dissolved
but 114.8 parts of dextrose. Compared with other systems described
below, this is but a slight diminution of solubility. The solid phase
in these equilibria is crystalline dextrose containing 1 molecule of
water of crystallization.
Systematic data obtained by Jackson and Silsbee are given in
table 142, p. 691, and plotted in figure 86. In this figure the point E
represents the solubility of pure dextrose in water at 30°C, that is,
54.64 percent, the solid phase being o-dextrose hydrate. Curve EG
shows the solubility of dextrose in the presence of increasing concen-
trations of levulose, while the straight line, EI, represents constant
relations between dextrose and water. The departure of solubility
curve EG from EI is seen to be slight.
362 Circular of the National Bureau of Standards
The line KL bisects the diagram, and is therefore the locus of all
solutions in which the ratio of dextrose to levulose is unity. In other
words, it is the locus of all invert-sugar solutions. At the intersection F
of the line KL with the dextrose solubility curve EG we have the point
which represents the composition of a solution which is saturated
with dextrose and which contains 34.85 percent of dextrose and 34.85
percent of levulose. In other words, this point represents the “solu-
WATER
S’
w/NZVVVVVVN
/\/\/\,\/\/\/\/\/\
w/VNZVNZYVVVVY
º
Áº/YYYYYY
ZººZººZVZVNZVNZ
*/Vºsºſ MV/\Z^^*
NZVNZVNZNZºº
DExTRose * 2, º ‘9 *2 % º *LEvulose
FIGURE 86.-The system deſctrose, levulose, and water.
EG is the Saturation curve of dextrose in the presence of levulose determined experimentally. The dotted
curves extending from the KJ coordinate are similar curves computed. The line KL is the locus of all
invert Sugar Solutions. The intersections of the dextrose Saturation curves with KL represent the com-
positions of invert Sugar Solutions Saturated at the respective temperatures with dextrose. M, alfalfa
honey; N, Sage honey; O, tupelo honey; P, Cuban honey. X’s on the water-levulose line show the
solubilities of levulose at 20°, 40°, and 55°C, respectively.
bility” of invert sugar, if “solubility” is understood to have the sig-
nificance that a solution containing 69.7 percent of invert sugar is
saturated at 30°C with respect to dextrose.
Since the salting-out effect of levulose is small, it is possible to
compute without serious error the solubility of invert sugar at other
temperatures by assuming a similar departure of the solubility curve
from the straight line joining the point I with the solubility of dextrose
in water at the respective temperatures. These computed solubilities
are given in table 141, p. 691, and plotted as dotted lines in figure 86.
The data presented here represent the system after attainment of
equilibrium. Equilibrium is approached very slowly even in the
presence of abundant quantities of the solid phase. If the solid phase
is not present, the solutions may remain supersaturated for long









Polarimetry, Saccharimetry, and the Sugars 363
periods. Honey is essentially a mixture of dextrose and levulose,
with the latter usually in excess. Jackson and Silsbee [10] have cal-
culated from the analyses of Browne [11] and Bryan [12] that all the
honeys for which analyses were available were supersaturated with
respect to dextrose. In those calculations, the small content of non-
sugars was disregarded and the small quantity of sucrose was added
arithmetically to the levulose, since the effects of these two sugars on
the solubility of dextrose were approximately the same. Proceeding
in this manner, they found that 92 American honeys analyzed by
Browne had an average supersaturation coefficient of 2.42 at 23° C
WATER
...ſºſyº/V/VVYYYYY
~~ w * > *5-5 --~~ * *
7N/º/V/\}\/\;\º/~As
14ſ N </3', ~ K/ Cº-º
5 J/ Cº-d
(7
\|_252
sº VVVVVs
zºº ãº
jº
*%+ Ö/XXXXXXX).
*
*
*
/\
/ . ." V º
sº 62 º -*- 2.
INVERT SUGAR” o º º ‘9 o º, * ‘sucross
FIGURE 87.-The system sucrose, invert sugar, and water.
MN, A C, and O Q are Saturation curves of sucrose in the presence of invert Sugar. HP is the composition of
invert Sugar Saturated with dextrose in the presence of sucrose. Pis the composition of a mixture of sucrose
and invert sugar Saturated with sucrose and dextrose at 30° C. RS represents the variation of P with
temperature. Solid lines are experimental; dotted lines are computed.
with respect to dextrose and a ratio of levulose to dextrose of 1.19.
The 72 imported honeys analyzed by Bryan had an average super-
saturation of 1.90 and a ratio of 1.20. The points M, N, O, and P in
figure 86 represent the composition of certain characteristic honeys.
Points M, N, and O, by coincidence, lie on the line QR, Q being the com-
position of crystalline dextrose hydrate. If in any of these honeys dex-
trose starts to crystallize, say, for example, at 23.15°C, the solution
becomes more and more impoverished with respect to this constituent,
and its composition moves to the right on the line QR until it becomes




364 Circular of the National Bureau of Standards
just saturated at R with respect to dextrose. For honey M, the
relative quantities of the resulting phases are proportional to the
lengths of the segments JM (solution) and MR (crystals). All
honeys are probably supersaturated with dextrose, and the fact that
they can be kept in fluid form for considerable periods of time is
due to the sluggishness with which the sugars crystallize.
(b) SOLUBILITY OF SUCROSE IN INVERT-SUGAR SOLUTION
Van der Linden [13] first showed that the solubility of sucrose in
the water of an invert-sugar solution was less than in pure water.
PARTS INVERT SUGAR IN | OO PART S WATER
FIGURE 88.-The system sucrose, invert sugar, and water.
The solubilities of sucrose at 23.15°, 30.0°, and 50.0° C in the presence of varying amounts of invert sugar.
The Solubilities are calculated to a constant water content. The lines AJ, MJ, and OJ are the loci of all
Solutions having a constant ratio of Sucrose to water.
Jackson and Silsbee [10] measured these solubilities with precision at
23.15°, 30.0°, and 50.0° C. Their measurements are shown in table
143, p. 692, and plotted in curves OI, AC, and MN in figures 87 and
88. The salting-out effect is shown best in figure 88 in which, if no
such effect occurred, the solubilities calculated to 100 parts of water
would have followed the horizontal dotted lines.
As the concentration of invert sugar is increased, the Saturation
point of dextrose is ultimately reached, and at complete equilibrium

Polarimetry, Saccharimetry, and the Sugars 365
dextrose would crystallize from this system upon further increase of
concentration of invert sugar. At this point the solution is saturated
with both sucrose and the dextrose constituent of the invert sugar and
is thus the concentration of maximum solubility which a mixture of
Sucrose and invert sugar can have. At 30°C this is plotted as point
P in figure 87. The sirup of maximum solubility contains 33.57
percent of sucrose and 45.44 percent of invert sugar.
As shown in table 141, p. 691, the solubility of invert sugar varies
considerably with temperature, and therefore the composition of the
sirup of maximum solubility varies with temperature. This change
in composition can be computed with fair approximation, and is
plotted on the curve RS in figure 87, and is also given numerically in
table 144, p. 692.
6. REFERENCES
erzfeld, Z. Wer. deut. Zucker-Ind. 42, 232 (1892).
. Siline, Bul. assn. chim. Sucr. dist. 52, 265 (1935).
. Jackson and C. G. Silsbee, BS Sci. Pap. 17, 715 (1922) S437.
jackson, C. G. Silsbee, and M. J. Proffitt, BS Sci. Pap. 20, 613 (1926)
§
;
J
S
;
. Gillis, Rec. trav. chim. 39, 677 (1920).
C. S. Hudson, J. Am. Chem. Soc. 30, 1767 (1908).
E. Saillard, Chimie & industrie 2, 1035 (1919).
J. Gillis, Rec. trav. chim. 39, 88 (1920).
R. C. Hockett and C. S. Hudson, J. Am. Chem. Soc. 53, 4454 (1931).
[10] R. F. Jackson and C. G. Silsbee, Tech. Pap. BS 18, 277 (1924) T259.
[11] C. A. Browne, Bur. Chem. Bul. No. 110 (1908).
[12] A. H. Bryan, Bur. Chem. Bul. No. 154 (1912).
[13] T. van der Linden, Arch. Suikerind. 27, 591 (1919).
XXIII. BOILING POINTS OF SUCROSE SOLUTIONS
1. GENERAL
When, for the purpose of controlling boiling operations, the con-
centration of a solute in a boiling liquid is to be determined, it is more
conveniently found from the relationship existing between the boiling-
point elevation and concentration of dissolved substances than by
direct determination. Heretofore, Claassen's [1] boiling-point eleva-
tion table for aqueous solutions of sucrose has been used in this manner
throughout the sugar industry and in laboratories. His table has
been subjected to some criticism [?], however, owing to the fact that
his values, determined at a pressure of 760 mm Hg, do not take into
account the effect of variations in pressure on the boiling-point eleva-
tion. As a result of this criticism, and at Claassen’s own suggestion,
Spengler, St. Böttger, and Werner [3] determined the boiling-point
elevation of pure and impure sugar solutions at various concentrations
under numerous conditions of pressure. From these observations
they plotted curves and from the curves selected values of boiling-
point elevations corresponding to even values of Brix for each pressure
and purity condition, from which they erected a table covering pres–
sures ranging from 4 to 2 standard atmospheres and concentrations
ranging from 15 to 90 percent of solids.
It was thought that for the purpose of constructing table 145,
p. 694, it would be well to correlate Spengler’s observed data by
means of empirical equations rather than to use the graphic method,
323414°–42 25
366 Circular of the National Bureau of Standards
By means of such equations, it is not only easy to calculate a table
which is interpolated readily but also to obtain other special values
not given in the table. Furthermore, values from the equation may
be compared with observed data.
It is interesting to note that in most cases values calculated from
these equations agree with Spengler's observed data better than they
do with his graphic data; therefore, the use of such equations through-
out the range of observed concentrations is justified. These equations
are as follows:
100 purity
logo At=2.6157X 10-9.V8–4.0185×10−"Nº-H4.2567 X 10-4A-1. 1979,
- 90 purity
logo At=3.101.3 × 10-ºx3–5.1209): 10~4Å*-i-4.9574). 10-ºx–1.2622,
80 purity
logio At=2.94.31% 10-"Yº–4.8211 X 10-4.Y”- 4.7512×10−"A – 1.1533,
70 purity -
logio At=3.31.38×10−"A*–5.5257X10-4A 4-H 5.1177.2 10-4.Y-1. 1305,
where At is the boiling-point elevation of the solution above that of
pure water at a pressure of 1 standard atmosphere, and X is the
concentration in percentage of solids.
Knowing the boiling-point elevation at 1 atmosphere (Atigo), the
boiling-point elevation at another pressure (At) may be calculated
by means of the following equation:
2
A-A*(#) º: e (110)
This is the same as eq. 127, the derivation of which is given on the
following pages.
2. DEFINITION OF BOILING POINT
The boiling point of a liquid may be defined as the temperature at
which its vapor pressure is equal to the pressure of the surrounding
atmosphere [4]. If the liquid is considered as a solution of two
substances, A the solvent and B the solute, then the total vapor
pressure is equal to the sum of the partial vapor pressures resulting
from A and B. If, however, the solute B is as nearly nonvolatile as
sugar, the total vapor pressure is that arising from the solvent only
and depends on the number of solvent molecules present in the vapor
phase per unit volume.
3. RELATIONSHIP BETWEEN VAPOR PRESSURE AND
CONCENTRATION OF SOLUTE IN A LIQUID
According to the law of Raoult, a definite relationship exists be-
tween the number of molecules present in the vapor phase and the
number of the same molecular species present in the liquid phase.
The vapor pressure of a liquid, p, is proportional to wo, the mole
fraction of the liquid which exists in the form of the same molecular
species as the vapor, or
p=kºro. (111)
Polarimetry, Saccharimetry, and the Sugars 367
If we consider the pure solvent by itself, in which case the same
molecular species exists in both the liquid and vapor phases, then
the mole fraction, alo, becomes unity, and we have the proportionality
factor, k, equal to the vapor pressure, po, or
k=p0, (112)
and from eq 109
p = poſto. (113)
Substracting both sides of eq 113 from po, we have
po- p = poºl poſo. (114)
Dividing eq 114 by po, there results
po-p
+-º-º: = 1 —- ºro. - 1 15
po I () (115)
However, by definition, alo is the mole fraction of solvent present
in the liquid, or
– – A –––A e
1—aro – 1 N.INTN.IN’ (116)
which, substituted in eq 115, gives
N
po-p-pºwTw-pº, (117)
in which aſ is the mole fraction of solute present in the solution, N
refers to the number of moles of solute present which have the molec-
ular weight of the solute, and No is the number of moles of solvent
present which have the molecular weight of the solvent in the vapor
State.
4. RELATIONSHIP BETWEEN VAPOR-PRESSURE LOWERING AND
BOILING-POINT ELEVATION
From the definition of the boiling point, it is readily seen that,
should the vapor pressure of the boiling solvent be lowered by the
addition of a solute it will cease boiling until equilibrium is again
established and the vapor pressure is raised to the same value it
had before the solute was added. An increase in vapor pressure
will be accompanied by a proportionate increase in the temperature or
dp0 po-p
Ol' dio TT–T. (118)
d
T-T-p-p+% (119)
in which T–To is the elevation of the boiling point of the liquid
which takes place in reestablishing equilibrium between the vapor
pressure of the liquid and the surrounding atmosphere, and dpo/dto
is the rate of change of vapor pressure of the solvent with change
in temperature.
368 Circular of the National Bureau of Standards
5. RELATIONSHIP BETWEEN BOILING-POINT ELEVATION AND
CONCENTRATION OF SOLUTE
Substituting in eq 118 the value of po-p from eq 117, we have
T– T-AT-pº (120)
OI’
WI7 - ºr - grº. - N --
AT=Br=BNºw, (121)
in which Bo is the boiling-point constant and represents the relation
existing between the vapor pressure of the solvent and the rate of
change in vapor pressure of the solvent with temperature. T-T)
or AT is the boiling-point elevation at an atmospheric pressure cor-
responding to To.
This equation is satisfactory for dilute solutions and is useful in
determining the molecular weight of various substances. At high
concentrations, however, the equation does not hold, because it does
not correct for the mutual attraction between the solute and solvent
molecules; therefore the relationship existing between the boiling-
point elevation and the concentration must be determined experi-
mentally for each substance.
6. RELATIONSHIP BETWEEN BOILING-POINT ELEVATION AND
ATMOSPHERIC PRESSURE
The boiling-point constant at any atmospheric pressure may be
determined from the approximate Clausius–Clapeyron equation
A' RT;
# =#–B. (122)
dT.
in which R is the universal gas constant and AH, the molal heat of
vaporization of the solvent at its boiling point, Th.
If eq 122 is substituted for its value in eq 121, we have
RTÉ
which is the boiling-point elevation equation for concentration a.
If this equation holds for any atmospheric pressure at which the boiling
point of the solvent is T0, then it is true for the pressure of 760 mm Hg.
When we change the subscripts of the factors in eq 123 to correspond
to these pressure conditions, we have
RT}.
AT;60– º (124)
and
AT, ºf (125)
=AH."
Polarimetry, Saccharimetry, and the Sugars 369
Dividing eq 125 by eq 124, we have
AT, (# )#
r - “ 2. * 126
AT., T \Tº) AH, (126)
Inasmuch as AH-60/AH, is the ratio of the molal heats of vaporiza-
tion of the solvent under two pressure conditions, their values may be
expressed in any unit, and we may rearrange eq 126 and write it as
T, *L750
/r –F– ; 127
Tºo Lo ( )
AT,- AT+8.
where AT, is the boiling-point elevation at any pressure, p, at which
the solvent boils at a temperature of T, and L, is the latent heat of
vaporization of the solvent at this temperature. A Troo is the boiling-
point elevation at a pressure of 760 mm Hg, in which case the solvent
boils at a temperature of Tºgo, which, for water, is equal to 373.16°K,
and Liao is the latent heat of vaporization of the solvent at this temper-
ature expressed in the same units as Lo. This equation, which is
Sometimes referred to as Tishchenko's equation [5], may be used to
determine the boiling-point elevation at pressures other than that for
which the values have been experimentally determined.
7. DERIVATION OF BOILING-POINT ELEVATION TABLE
As has been stated elsewhere, empirical equations were calculated
from Spengler's observed data. These equations were developed in
the following manner:
Inasmuch as no observations were made at a pressure of exactly 1
atmosphere, the first step was to adjust the values determined at the
pressure nearest 1 atmosphere for each concentration and purity to
the value it would have at exactly 1 atmosphere. This was done by
means of eq 127 expressed in the form
2
Tºo L,
j- J F-- 7 128
T, Lºgo ( )
Atºo – A to
in which Loſ Liao was determined for each observed temperature by
the equation *
L.
L = 1.1074–1024t X 10-0–5tº X 10-9, (129)
760
where t is the temperature in degrees centigrade corresponding to the
observed temperature, T, which is expressed in degrees Kelvin, or
t=T,-273.16. (130)
Values given by eq 129 in the range 60° to 130°C are in agreement
with values of L, according to Osborne, Stimson, and Ginnings [6].
The use of eq 128 to adjust the observed values of the boiling-point
elevation to the boiling-point elevation which the solution would have
at 1 atmosphere resulted in a very small change from the observed
values. In all cases this change was less than 0.10°C.
370 Circular of the National Bureau of Standards
These adjusted values were fitted to four empirical equations, one
for each purity reported, by the method of least squares. They have
the form
logioA Tºgo-ax *-H by *-H clº–H d,
where A Theo is the boiling-point elevation of the solution at 1 atmos-
phere; X is the concentration of solids in solution, in percent (Brix);
and a, b, c, and d are constants from the least-squares data. The
equations on page 366 show the values of the constants for each of
the four equations.
Boiling-point elevations at other pressures were calculated from
the values found by these empirical equations by means of eq 127.
The values so calculated deviate from the observed values by a lesser
amount than they do from the graphic-method values.
8. REFERENCES
| H. Claassen, Z. Ver. deut. Zucker-Ind. 54, 1161 (1904).
] A. L. Holven, Ind. Eng. Chem. 28, 452 (1936).
] O. Spengler, S. Böttger, and E. Werner, Z. Wirtshaftsgruppe Zuckerind. 88,
521 (1938).
[4] H. S. Taylor, A Treatise on Physical Chemistry (D. Van Nostrand Co., Inc.,
New York, N. Y., 1931). &
[5] I. A. Tishchenko, Soviet. Sakhar Nos. 11/12, 31–3 (1933); Chem. Zentr. 2,
352 (1934).
[6] N. S. Osborne, H. F. Stimson, and D. C. Ginnings, J. Research NBS 23,
261 (1939) RP1229.
XXIV. CANDY TESTS
1. INTRODUCTION
(a) GENERAL
The need of a standard or reference procedure as a starting point
for a rational development of various types of candy tests has been
felt for some time. The method outlined below for simple barley-
sugar tests, as well as the special equipment specified for carrying it
out, has been developed at this Bureau, not only as a basic procedure
but also as a standard procedure for the routine testing of commercial
sucrose with respect to heat stability. It is founded upon an old pro-
cedure,” which generally is attributed [2, 4, 5, 7, 9] to S. C. Hooker,
whose directions, as transmitted to various laboratories under his
supervision * were stated in approximately the following words.
(b) HOOKER TEST
Half a pound (227 g) of sugar is placed in a copper casserole of the following
dimensions, 4%6 inches diameter at the top, 2% inches diameter at the bottom, and
height 2%6 inches (inside measurements). After the addition of 3 oz (89 cc)?”
of distilled water, the casserole is placed over the naked flame of a burner. The
flame should be regulated previously to such a size that the total time of heating
required to bring the temperature to 350° F (177° C) is 21 to 25 minutes. (It has
been found that this condition will be fulfilled if 200 cc of water at room tempera-
ture is brought to a point of vigorous boiling in 4% to 5 minutes.)
* The procedure was described in 1897 by Wiechmann [1], not as a control test but as a method of preparing
“amorphous sugar” to be used in a study of allotropy in sucrose. The two sections of the description, sepa-
rated in his paper, cover roughly every point of the Hooker procedure almost word for word. The paper
includes analytical data on a dozen different candy plaques, one of which had been stored under a bell jar
With calcium chloride desiccant while it developed a crystallizing area, of which there is presented a record
of the rate of growth to a diameter of 51 mm and an excellent photograph at this stage.
* Hooker's directions are quoted here, because no exact statement of them is known to be readily avail-
able elsewhere.
*In certain copies of Hooker's directions, which probably were intended for use with wet-packed con-
fectioners’ Sugars, the quantity of water was stated as “87 cc.”
Polarimetry, Saccharimetry, and the Sugars 371
The contents of the casserole are continuously stirred until the sugar has dis-
Solved, and the stirring rod is removed. If the size of the flame has been properly
adjusted the solution should start to boil in about 5 minutes after being first put
over the flame. At this point an inverted watch glass is placed over the casserole;
Otherwise the sugar will be apt to crystallize as the evaporation proceeds.
After the heating has continued precisely 15 minutes from the time when the
casserole was first placed over the flame, the watch glass is removed and the solu-
tion is then thoroughly and constantly stirred without a moment's interruption
until the boiling point has reached exactly 350° F (177° C), the thermometer being
used as a stirring rod. The casserole is than instantly removed from the flame
and its contents are as rapidly as possible emptied upon a polished copper slab
14x14x)4 inches in size. In a few minutes the candy becomes brittle and can be
broken up for any tests it is desired to make.”
The Hooker procedure is , deficient chiefly in reproducibility.
Experiments conducted at this Bureau indicate that most of this
variability can be eliminated through the use of more definite specifica-
FIGURE 89.-Copper casserole as used in Hooker’s procedure.
The drawing is adapted from the illustration presented by Murphy [5].
tions for the apparatus and procedure and by the omission of hand-
stirring of the boiling sirup [4]. As a result of this study, a method
has been developed which is designated the “National Bureau of
Standards simple barley sugar test.”
2. NATIONAL BUREAU OF STANDARDS METHOD FOR BARLEY
SUGAR
The Bureau method varies from the Hooker procedure in several
respects, as summarized later in this discussion. All of these modifica-
tions are important to the convenience and uniformity of the test
procedure, as also to the precision and reliability of the results,
especially as obtained by different operators, and particularly as
obtained in different laboratories. The following is the improved
procedure.
38 Most candy and sugar technologists regard commercial sucrose as being the “weaker” the greater the
degree of hydrolysis which it undergoes upon conversion into hard candy under standardized conditions
{2, 4, 5, 9, 10, 11]. Hooker's procedure originally was intended to indicate, through direct polarization of
the resulting candy project, the relative “strength” of any lot of Sugar, conceived as the apparent resistance
of the sugar to hydrolysis under such conditions. In Hooker’s laboratory no other tests of the candy prod-
uct were made. In later development of candy test methods, various other observations have been applied
to the candy product as criteria of the quality of the sugar. When Osborn [2], in 1912, introduced candy test
methods as a means of control of quality in beet sugar production, substituting porcelain casseroles for those
of copper, he immediately gave heed to the rates of crystallization of the individual candy products and also
devoted special attention to the color of the candy and to the tendency of the Sirupy mixture to “foam” upon
first coming to a boil in the candy test. He finally omitted the direct polarization in most cases. Empir-
ical means of roughly estimating in quantitative form, the tendencies of the sugar to cause foaming and
caramelization were developed somewhat later by Proffitt [4].

372 Circular of the National Bureau of Standards
(a) PROCEDURE
1. Weigh 250.00 +0.05 g of the sugar sample on a dry basis and
make up to a weight of 350.00 +0.05 g with cold equilibrium water *
in a 600-ml chemical-resistant glass beaker (provided with a ther-
mometer clasp, as specified on p. 375) previously tared with the
thermometer and the notched watch-glass cover.
2. With the thermometer used as a stirring rod, loosen the com-
pacted crystals from the bottom of the beaker, and mix them evenly
with the liquid to form a homogeneous suspension. Continue the
stirring until the crystals easily remain in suspension for some time, or
until the temperature has ceased falling.
3. Replace the thermometer in its clasp (to avoid injury of the
thermometer and the dripping of sirup), and set the beaker upon its
supports in the stove with the burner alight and with the flame in
correct stable adjusment. Immediately resume stirring of the mix-
ture with the thermometer to prevent settling of the undissolved
crystals.
4. On the instant the starting temperature of 30° C (86° F) is
indicated, note “zero time” in the heating cycle (as for example, by
the starting of a stop watch or a second counter).” Proceed with the
stirring until a temperature of 70° C (158°F) is indicated, when crys-
tals of fine or medium granulated sugar ordinarily should be practi-
cally all dissolved.” Clasp the thermometer at its proper working
level, which will bring the bottom of the bulb to the position indicated
in the drawing (fig. 90). Immediately cover the beaker with the watch
glass as indicated in the drawing. Observe the sirup closely as the
boiling point is approached ” for its behavior during the transition
interval between quiescent heat absorption and steady boiling is an
important criterion of the probable stability of the sugar in storage
as well as in candy making. There should be no considerable increase
in the apparent volume of the sirup, not more than a trace of foamy
Scum should collect on the surface, and the transition interval should
last not more than 30 seconds.” Steady boiling usually is barely estab-
lished when the thermometer indicates a temperature about 6° C
(11° F) higher than it would indicate in boiling water in the same
beaker. This is assumed to be the initial boiling temperature of the
sirup.
5. Allow the sirup to boil under cover until its indicated temperature
is just 120° C (248° F) [4] (which in a 23-minute cooking interval
occurs approximately 15 minutes after the start of heating). On the
instant this temperature is indicated, lift the watch glass at one edge
and tip it to drain most of the adhering condensate down the side of
the beaker into the boiling sirup. Do not disturb the sirup in any other
manner. Place the wet watch glass into a drying oven at a temperature
of about 105° C (221°F) without washing, for it may retain a small
amount of sirup.
Tº Equilibrium water is defined on p. 271.
25 If temperature-gradient data are desired, record elapsed time against a previously prepared Schedule of
temperatures. Such gradients are a valuable means of interpreting results in certain cases.
20 If grains still can be felt with the thermometer or can be seen, remove the beaker from the stove and
proceed with the stirring without further heating until the refractory grains have disappeared. Return the
beaker to the stove, and stir the sirup again until the temperature of 70° C is regained. Do not include the
time consumed in these Operations in the recorded duration of the cooking interval.
27 Remove the watch glass during the transition interval only if dew formation on the undersurface in-
terſeres with observation, or if its removal is required for the measurement or the quelling Of foam. (See
b (1), p. 373).
28 If a layer of sudsy foam accumulates on the surface of the sirup, proceed as indicated under b (1), p.373.
Polarimetry, Saccharimetry, and the Sugars 373
6. On the instant a temperature of precisely 176.7° C (350° F) is
indicated, remove the beaker from the stove, simultaneously noting
the time (as by the stopping of the timer device), and dump its con-
tents all at Once onto the center of the cooling slab. This operation
should be performed in such a manner as to form a nearly circular
plaque. When the stream breaks, turn the beaker to an angle of
about 45° and allow the sirup to drain into the center of the plaque
for 10 +2 seconds. Lift the beaker with a turn which brings the
threads of sirup into its mouth, and set it upon a quenching sheet of
%-inch aluminum or copper to prevent charring of the adhering sirup
in the bottom of the beaker. Cover the beaker with the dried watch
glass now taken from the oven and, when cooled to room temperature,
weigh the whole assembly.
7. Five minutes after the pouring of the candy, strip the plaque
from the water-cooled slab and place it in a desiccator or dry-air closet
until it has cooled to room temperature. When the plaque is cool,
proceed as indicated under b (2), below.
(b) OBSERVATIONS FOR THE INTERPRETATION OF RESULTS
(1) FoAM NUMBER.—When a layer of sudsy foam accumulates
upon the surface of the sirup as it approaches the transition interval,
the apparent volume of the mixture probably will expand suddenly at
initial boiling [2, 4). To obtain a roughly quantitative statement of
the phenomenon, proceed as follows:
Observe the number of seconds elapsing from the instant the rapid
expansion begins until the moment the foam subsides to its minimum
volume, and record the result as “duration of foaming.” Observe
also the distance in centimeters from the surface level of the quiescent,
nonfoaming sirup to the highest level reached by the general surface
of the foam on expansion, convert the result to percentage of increase
in volume, and record the number as the “volume of foam.” The
product of these two numbers is the “foam number” [4, 6].
Space is available in the beakers for the accommodation of but little
more than a doubling of the apparent volume of the sirup with the speci-
fied size of sample. If the expansic n much exceeds this value, at the
standard rate of heating, it may result in the overflowing and loss of a
portion of the sirup, with consequent fouling of the stove and burner.
If this misfortune threatens, reduce the rate of heating; do not disturb
the flame but hold the vessel by hand at a greater distance above the
flame, or hold it intermittently over the flame until all danger of loss
is past. Do not include any prolongation of the heating which is in-
volved in the quelling of foam as a part of the cooking interval.
(2) ExAMINATION OF THE PLAQUE.--Notice the general appearance
of the candy, especially with respect to color, transparency, inclusion
of bubbles and specks, etc., and state the results in qualitative form.
Weight of the plaque.—When the plaque has cooled to room temper-
ature, weigh it with a precision of +0.05 g.
Projected area of the plaque.—Measure the projected area of the
plaque, preferably by following the periphery of the disk itself with
the stylus of a planimeter specially designed for such purposes. If
this means is not feasible, first trace the outline of the plaque upon
paper and later measure the area enclosed by the tracing. Express
the results in square centimeters.
374 Circular of the National Bureau of Standards
Slump or specific area of the plaque.—Divide the number represent-
ing the projected area by the number of grams in the weight of the
plaque, and record the quotient as the “slump”, or specific area, ex-
pressed as square centimeters per gram. The numerical value of this
quotient, under uniform conditions of testing, increases with increasing
weakness of the sugar [13].
Mean thickness of the plaque.—Measure the thickness of the plaque
at a minimum of 20 random points distributed evenly over the plaque,
preferably by means of a dial-type thickness gage. In lieu of this,
pieces of the plaque may be measured with an ordinary micrometer.
The plaque is thicker the stronger the sugar from which it was pre-
pared (with uniform conditions of testing) [13].
Color measurement of the solid candy.—Estimate the transmission
of light of 560 mg wave length (or of three or more wave lengths, if
preferred) at several clear points on the plaque or at clear points on
several pieces. Compute the transmissions for layers of exactly 5 mm
thickness. To minimize surface reflections, observe the pieces while
freshly immersed in a water-clear, slightly supersaturated sirup of
pure sucrose contained in a wide, open-top colorimeter cell of about
1-cm length (on the optical axis). Employ any suitable instrument
(chap. XIX), and correct the results for any perceptible absorption of
light by the immersion sirup [13].
Yield and overweight of the candy.—The total yield, y, of the candy
is the sum of the weight of the plaque and the weight of the candy
adhering to the boiling-vessel, thermometer, and cover. The “over-
weight” in grams is the difference expressed by (y—wt of dry substance
introduced), which, in all standard tests, is (y–250). It represents
approximately the weight of the residual water retained by the candy,
partly combined as water of hydrolysis, partly as solvent or solute in
the supercooled solution. In standard tests it is expressed as a per-
centage of the sample weight simply by multiplying by the factor 0.4.
Breaking of the plaque.—The relative brittleness or toughness of the
plaque can be estimated by breaking the plaque with a suitable impact
device. Ordinarily, it is simply broken by hand. In either case, the
pieces are placed promptly in a container, such as a glass-top mason
jar which can be closed to protect the candy from the moisture of the
atmosphere. If the candy is to be examined in aqueous solution, the
container should be tared.
(3) ExAMINATION OF THE CANDY IN AQUEOUS SoLUTION.—From
the net weight, w, of the candy stored in the container, and the yield
of the candy per gram of the dry substance introduced, compute the
weight of dry substance introduced (see above) equivalent to the
contents of the container, as Sw/y, where s represents the weight of
dry substance in the sample (250.00 g in all standard tests). Add
equilibrium water until the total weight of the contents is precisely
double this quantity, i. e., 2sw/y. Cover the container securely and
without the application of any heat, shake or rotate it, preferably by
mechanical means, until the candy is completely dissolved. Use this
stock solution for whatever tests or analyses are to be made on the
aqueous solutions, keeping in mind the fact that 1 g of the original dry
substance of the sample is represented by 2 g of the stock solution.
Polarimetry, Saccharimetry, and the Sugars
375
(c) APPARATUS
(1) BoILING-VESSELS.–Glass beakers, Griffin form, 600-ml capac-
ity, of chemical resistant, low-expansion Pyrex or equal glass must be
used as the boiling-vessels. Each beaker is to be provided with a
notched watch-glass cover and with a quickly detachable combination
handle and thermometer support with quick-opening spring-actuated
clasp, as indicated in figure 90. For lightness and cleanliness, the
handle and thermometer support are constructed mainly of aluminum.
For uniformity of results, the thermometer bulb should be located
precisely as indicated in the drawing, and the burner should be of
precisely the form and arrangement indicated in figure 92.
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FIGURE 90.-Boiling-vessel assembly.
Consists of 600-ml chemical-resistant-glass beaker provided with a notched water-glass cover, thermometer,
and handle set carrying the thermometer support with spring-actuated clasp. The aluminum handle
set is clamped onto the beaker by means of the hinged hoop bands which are secured by closing the handle
shell, jackknifewise, over the straight protruding ends of the bands. It is retained at a fixed level on the
beaker by the V-shaped wings which bear upon the sides of the lip of the beaker, and by the short hook
which rests in the notch of the lip.
variations in the thickness of the beaker bottoms cause relatively large
variations in the duration of the cooking interval with any given
adjustment of the burner and gas supply, beakers which are to be used
Interchangeably on a particular adjustment of the heating equipment
should be carefully matched as to weight and as to heat transmission.
A counterpoise, preferably adjustable, should be provided for the
taring of each assembly. Since the handle sets are so easily removed,
and should be removed while the glass parts are being washed, all
weighings may be made without the handle sets. Thus consecutive
tests can be run without loss of time by providing a sufficient number
of matched beakers and thermometers with but two handle sets.
Since


376 Circular of the National Bureau of Standards
(2) HEATING DEVICEs.
Standard device with flow manostat for gas heating.—This apparatus,
which will be described in greater detail elsewhere, practically meters
the gas to the burner jets at a steady rate of flow. The heat capacity
of the burner and the associated parts is small; only a few minutes of
operation is required to establish a state of steady output of heat to
the boiling-vessel, provided that the calorific value of the gas is approx-
imately constant. The apparatus is comprised of the following parts:
Flow manostat.—The essential feature of the manostat, figure 91, is
the balanced valve, V which floats in the orifices of the plates, OP,
and is actuated by the float, F, which in turn is operated by changes in
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FIGURE 91.-Flow manostat for gas pressure regulation.
The preferred form, as illustrated at A, has a double self-balancing valve which floats freely in the two gas
orifices and does not close the openings completely at any level, as illustrated more clearly in the enlarged
view C. A simpler form of regulator with a single, Spring-balanced valve is illustrated in view H.
the level of the hydrostatic liquid in response to changes in the pres-
sure of the regulated gas stream. The floating valve is retained in the
centered position in the orifices of the plates OP by the bearing plates
B (as lettered in the enlarged view, C). The valve-and-float assembly
is further stabilized by the ballast weight, B (refer to views A and B).
The liquid tank J, the float chamber with the gas outlet O and the top
closure S, may be made of glass, as indicated, for the convenience of
visibility of the moving parts during the adjustment and operation
of the manostat. However, a simpler construction has proved amply
satisfactory in service. The pointer, P., (view B) is convenient with
either the single or the double valve [13].
Gas from the service pipe enters at I, and the regulated gas streams
for two or three burners is taken off at O. Since the regulation of
pressure is dependent in part upon a steady outflow at O, which is to










Polarimetry, Saccharimetry, and the Sugars 377
HALF PLAN VIEW
OF TOP
36 HOLES OF THE PROPER
SIZE FOR THE PARTICULAR
TYPE OF GAS AVA | LABLE
WHERE THE BURNER IS TO
BE USED, 6 IN EACH RAY
OF THE STAR ON CIRCLES
OF 6, 12, 18,24, 30 & 36 mm
RADIUS, RESPECTIVELY,
WITH NO HOLE AT CENTER.
—-H2
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s:
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REMOVABLE STUFFING BOX
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C ENT | MET E R S
FIGURE 92.-Special star burner.
Vertical section, indicating the preferred form as constructed with water jackets and with a micrometer-
actuated needle valve which is readily removable for operation of the unit as a simple disk-nozzle injector.
The needle rests in a tapered socket in the micrometer spindle.










378 Circular of the National Bureau of Standards
say, a steady consumption of gas by the burners, it follows that no
change can be made in the number of burners without altering either
their average individual output or else the adjustment of the regulator.
Special star burners.-The essential feature of the form of gas
burner which is to be used with glass beakers (but also is suitable for
use with other types of boiling-vessel) is the arrangement of the
multiple-flame jets upon the curved upper surfaces of the six rays,
as indicated in the drawings, figures 92 and 93. Desirable but not
indispensable features are, first, the unobstructed knife-edged disk
nozzle for the injection of the gas into the mixing chamber, which
FIGURE 93.-Special star burner as constructed with water jackets and disk nozzle,
but without micrometer and needle value.
is readily removable for cleaning or exchange: and second, the water-
cooling of the nozzle chamber and nozzle and the mixing chamber. [13]
The disk nozzles are to be properly formed of corrosion-resistant
material, such as monel metal or stainless steel. A number of inter-
changeable nozzles with assorted diameters of orifice should be pro-
vided to facilitate adjustment of the burner output. For a given rate
of discharge, the orifice of a thin disk nozzle presents maximum clear-
ance for the flow of gas and minimum probability of clearance con-
traction through accumulation of dirt, tar, or polymerization waxes.
Hence the disk nozzle provides stability and reliability of heat out-

Polarimetry, Saccharimetry, and the Sugars 379
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FIGURE 94.—Stove assembly with the burner arrangement illustrated in Figure 4.
To indicate the correct relations among the beaker, burner, and top plate, the operating position of the
boiling-vessel assembly is illustrated in broken outline. WI represents the water inlet, WO the Water
outlet, and GI the gas inlet.










380 Circular of the National Bureau of Standards
put by the burner. At some sacrifice of these features, but at little
sacrifice of accessibility for cleaning when deposits appear, provision
can be made for adjustment of the output capacity of a burner with
disk nozzle by installing in the nozzle chamber a long-taper needle
valve with a maximum thrust diameter somewhat less than the
Figure 95.-Stove assembly with the burner arrangement illustrated in Figure 5.
The boiling-vessel assembly is in position for the carrying out of a candy test.
diameter of the orifice, which it is arranged to penetrate concentrically.
The arrangement is indicated in figure 92. -
In figures 92 and 94 the nozzle chamber into which the gas inlet,
GI, leads is enveloped by its water jacket, Hi, through which the
current of water passes from its inlet, WI, to the transfer duct leading
to the mixing-chamber water jacket, H2, whence it flows to waste
through the outlet, W0. By means of the vertical adjustment pro-
vided for the nozzle chamber assembly, the cap, C, can be brought to

Polarimetry, Saccharimetry, and the Sugars 381
act as a shutter against the mouth of the venturi of the mixing cham-
ber to control the uptake of primary air. Thus an annular inlet,
open at the bottom, is formed for the primary air between the jacket
of the nozzle chamber and the skirt of the mixing chamber.
Stoves, or support assemblies.—The functions of the stove, figures
94 and 95, are to support the boiling vessel and burner in constant
locations and thus maintain the correct spatial relations between
them; to shield the flames and hot combustion gases from the dis-
turbances caused by cross drafts (provided they are not too strong)
and otherwise to assist in directing the hot gases against the bottom
and sides of the vessel below the surface level of the solution; and
finally, to divert the hot gases away from the sides of the vessel
above the solution.
The top plate, of transite board with centrally located hole into
which the beaker fits, is supported on three strap-iron legs which
also support the truncated conical flame shield of polished sheet
aluminum. The lower ends of the legs are bolted to the wide iron
base upon which the burner is mounted, which in turn is supported
upon one fixed foot and two leveling screws.
In stoves for use with glass beakers, which for any particular nomi-
nal size vary slightly in diameter, the central hole is cylindrical and
just large enough to avoid any binding when the largest beaker in the
set is inserted. The beakers are supported at the correct height
above the burner (and at the correct insertion through the plate) by
means of three thin Monel metal or stainless steel brackets attached
to the under side of the plate. The boiling-vessel assembly should
be set into the stove with the center of the thermometer bulb in a
º plane bisecting the angle between two adjacent rays of the
ULI'IleI’.
Inclined manometers (or gages).-For the convenient observation of
the service pressure and the regulated pressure of the gas in the making
and inspection of the adjustment of the flow manostat and burners,
provide a pair of oil- or water-filled hydrostatic gages with scales about
100 cm long and inclined at suitable (and therefore different) angles.
Other types of heating equipment.—Electric-resistance heaters, for
example, may be used in place of the special star burner with flow man-
ostatic control described above, provided ample comparative candy
tests on samples of a sufficient range of quality have demonstrated
º they yield results equivalent to the results obtained with the
|UII’Il GI’.
Adjustment of the heating device.—The heating device is adjusted in
the following manner: A minimum of four standard simple barley-
sugar tests (basic method, p. 372) are run on a pure sucrose sample
(p. 385), and the heating device is so adjusted that the mean duration
of the time of cooking, between the temperatures 30° and 176.7°C,
shall be 20 minutes +20 seconds. Make similar tests at sufficiently
frequent intervals to assure that adjustment is not changing.
The first (or coarse) adjustment is made by installing the proper
disk nozzle in the burner. The nozzle is of such a size as to yield
nearly the required interval. Final adjustment is made by changing
the level of hydrostatic liquid in the flow manostat. As a preliminary
criterion of adjustment, it is convenient to heat 300.0 g of water in the
3234 14 °–42 26
382 Circular of the National Bureau of Standards
600-ml beaker through the 50-degree interval from 30° to 80° C (or
the 90-degree interval from 86° to 176° F). The cooking interval
will be approximately six times the time required to heat the water
through the specified interval, i. e., the water should heat in approxi-
mately 3 minutes 20 seconds as the mean of a minimum of four tests.
(3) THERMOMETERs.—Mercury-in-glass thermometers are suitable
for all ordinary candy-test procedures, provided the instruments are
properly constructed. They may be graduated in either the centigrade
or the Fahrenheit scale, as specified by the user, but must not be gradu-
ated in both scales on the same thermometer. They should conform
preferably with the specifications presented below, which provide an
instrument of low lag. Alternatively, thermometers conforming with
ASTM Specifications D 183–25 or thermometers for general use may
be employed.
SPECIFICATIONS FOR CANDY-TEST THERMOMETERS
TYPE.—Etched stem, glass.
LIQUID.—Mercury.
RANGE AND SUBDIVISION.—Minus 10° to plus 200° C, in 1.0°, with expansion
chamber at the top to permit heating to 50° above the upper limit of the scale,
or plus 14° to 390°F, in 2.0°, with expansion chamber at the top to permit heat-
ing to 90° above the upper limit of the scale.
ToTAL LENGTH..—340 to 360 mm.
STEM.–Plain front, enamel back, made of suitable thermometer tubing. Diam-
eter 6 to 7 mm.
BULB.—Corning normal or equally suitable thermometric glass. Diameter not
less than 4 mm and not greater than 5 mm. Length not less than 10 mm and
not greater than 15 mm.
DISTANCE FROM BOTTOM OF BULB To — 10° C OR 14° F MARK.—80 to 100 mm.
DISTANCE FROM 200° C OR 390° F MARK TO TOP OF THERMOMETER.—30 to 70 mm.
LENGTH OF UNCHANGED CAPILLARY between top of bulb and first graduation
mark, 60-mm minimum; and between the last graduation mark and the expan-
sion chamber at the top, 10-mm minimum.
Top FINISH.—Glass ring.
SPACE ABOVE MERCURY.—Filled with nitrogen or other suitable gas.
GRADUATION.—All lines, figures and letters are to be clear cut and distinct.
Maximum width of graduation lines, 0.1 mm. On the centigrade scale, all
graduation lines at multiples of 5° are to be longer than the remaining graduation
marks. Graduations are to be numbered at each multiple of 10°. On the
Fahrenheit scale, all graduation lines at multiples of 10° are to be longer than
the remaining graduation marks. Graduations are to be numbered at intervals
of 20° beginning at 20°.
IMMERSION, 76 mm.—The words “76-mm immersion” and a line around the stem
; a distance of 75 to 77 mm above the bottom of the bulb are to be etched on
the Stem. .
SPECIAL MARKING-The words “NBS CANDY TEST’’, a serial number and the
manufacturer’s name or trade-mark shall be etched upon the stem. The mark-
ing “C” or “F”, as the case may be, shall be etched on the front of the stem
above the scale.
SCALE ERROR.—The error at any point on the scale, when the thermometer is
standardized at 76-mm immersion in a room at 25° C temperature, shall not
exceed 19 C or 2° F.
CASE.-The thermometer shall be supplied in a suitable case, on which shall
appear the marking “NBs CANDY TEST, -10° To 200° c” or “NBs CANDY TEST,
14° to 390° Fº, as the description may require.
NotE.—For the purpose of interpreting these specifications, the following defini-
tions apply:
The total length is the over-all length of the instrument, as supplied.
The diameter is that measured with a ring gage.
The length of the bulb is the distance from the bottom of the bulb to the
beginning of the enamel backing.
The top of the thermometer is the top of the finished instrument.
Polarimetry, Saccharimetry, and the Sugars
383
(4) CooDING SLABs.
Water-cooled slabs for standard plaques.
As constructed according to the drawing, figure 96, two circular
plates of aluminum are drawn down at their peripheries to form short
skirts which can be placed edge to edge to form the water chamber.
These are notched in such a way that when so placed, a pair of circular
openings can be formed for the insertion of the inlet and outlet nipples.
Within the chamber, with its inlet nipple protruding through one of
the openings, is placed a flat spiral coil of aluminum tubing in contact
with both plates and having its open discharge end at the center of
the assembly. The outlet nipple is inserted in the other hole. The
coil is tack- or spot-welded to one of the plates at a sufficient number
of points to assure its remaining in place, and the joints between the
skirts, as also between the nipples and the skirts, are carefully welded.
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FIGURE 96.-Water-cooled slab.
Plan view and side elevation. The latter is quºtioned to illustrate the construction described in
the text.
The faces marked f are to be carefully polished and they must not be
marred in use.
Alternatively (but with some disadvantages), the
slab may be constructed of copper, with brazing or silver soldering
in place of welding.
(This slab may be constructed in any other manner which achieves
approximately the same result and cools the candy evenly by a flow
of water directed to absorb the heat most rapidly at the center of the
plaque, where the temperature is highest.
In service, the slab should be level. Water should enter the coil at
a temperature of 25°C and should flow at a rate of about 5 liters per
minute into the center of the water chamber, thence through the
spiral path between contiguous turns of the coil to waste through the
outlet nipple, - -










384 Circular of the National Bureau of Standards
Quenching plate.—For the prompt cooling of the superheated bottom
of the beaker (to prevent charring of the residual sirup, which fouls
the glass and complicates the washing), provide a square piece of
%-inch aluminum or sheet copper measuring 12 to 14 inches square.
Aluminum is preferable to copper because of its lighter weight.
(d) HEATING CYCLE
. The heating cycle of any candy, sugar test includes the cooling
interval (during which the material is restored to room temperature)
as well as the cooking interval, which itself includes three main
| 80
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FIGURE 97.-Temperature gradients
developed during the 20-minute cook-
1ng interval of a simple barley-sugar
test conducted according to National
Bureau of Standards procedure,
using a 600-ml glass beaker on the
Stove assembly illustrated in figure 7.
Two regimes of heating prevail in the first (or
preboiling) phase of this procedure. The
resulting four regimes of heating: (1) with
stirring of the uncovered sirup, (2) without
stirring of the covered sirup prior to boiling,
(3) with boiling of the sirup under cover, and
(4) with boiling of the sirup in the open beaker
are set off by the three abrupt flexures of the
temperature curve (a) at 70° C, where stirring
is terminated; (b) at the transition from quies-
cent heating to vigorous ebullition of the sirup;
and (c) at 120°C, where the sirup is uncovered.
regimes, or phases, of heating, as
indicated by the temperature gradi-
ents of the cooking interval pre-
sented in figure 97. These three
phases comprise (1) The bringing of
the mixture to the boiling point
(accomplished under two regimes
in the NBS method (2) the con-
centration (usually under cover) to
proximate saturation at the current
temperature, and (3) the further
concentration of the sirup under
continuously increasing supersatura-
tion to the terminal temperature.
From what is said below of the utility
and reliability of the candy test, it is
evident that the most advantageous
duration to select for each of these
intervals is that which differentiates
the samples most precisely and most
reliably in respect to their stability
properties. The same thing is true
of the terminal temperatures. If the
heat effect is carried beyond an
established optimum in either re-
spect, the separation becomes blurred.
(1) DURATION OF THE CookING
INTERVAL.-In all standard proce-
dures conforming with these general
methods of candy testing, the correct
cooking interval is assumed to be
that which results when the test is
conducted in apparatus which has
been carefully standardized and the heating device adjusted with
reference samples of pure sucrose (p. 385) in the basic simple barley-
sugar test, as directed on page 372. As long as the specified adjust-
ment of the apparatus is maintained the correct cooking interval will
be yielded in any standard test on a sample of any appropriate
composition, although the actual time elapsing between 30°C (86°F)
and the terminal boiling temperature may be not quite the 20 minutes
+20 seconds, required under reference conditions.
From this it follows that if the mean duration of the cooking interval
in a minimum of four standard simple barley-sugar tests on an

Polarimetry, Saccharimetry, and the Sugars 385
“unknown” sample of commercial sugar should deviate from the mean
duration observed in calibration with the prototype sample by very
much in excess of +20 seconds, such deviation from the mean could
be regarded as a characteristic property of the commercial sample.
(2) DURATION OF THE CoolTNG INTERVAL.-Although the decom-
position of the ingredients of a candy test is most rapid at the terminal
boiling temperature, there seems to be less promise of a gain in
differentiation of samples [10, 11] by either delay or prolongation of the
cooling interval than in shortening it and making it more uniform.
This fact sufficiently explains the specification of the water-cooled
slab in standard tests [13].
(e) SAMPLES
(1) TYPEs of MATERIALs TESTED.—This discussion of the National
Bureau of Standards improved simple barley-sugar test is limited to
its use (a) in the standardization of equipment for candy tests in
general, which involves only reference samples of specially purified
sucrose (see below); and (b) in the routine inspection of commercial
white sugars, where ordinarily only samples of char-refined sugars
(and direct-consumption sugars of comparable purity) will be involved.
A discussion of the modifications of the basic procedure permitted for
the setting up of other types of candy tests will be presented elsewhere
|13]. *
(2) REFERENCE SAMPLEs.-Reference samples for the purposes of
candy-test procedure include two general classes of materials: (a)
Specially purified lots of an individual chemical substance, such as
sucrose, which, for practical purposes, are essentially reproducible.
These may be designated primary or prototype samples, (b) materials
such as commercial sucrose, dextrose, and corn sirup. As a class, these
may vary considerably in composition.
For the most critical reference purposes, prototype sucrose prepared
according to the method of Bates and Jackson [3] is specified. For the
standardization of equipment (p. 381), grade A char-refined sugar
generally serves for the reference sample which, although specially
purified as a commercial product, really belongs to the second class of
reference material.
(f) IMPROVEMENTS OF THE NATIONAL BUREAU OF STANDARDS METHOD OVER
THE HOOKER PROCEDURE
For the reasons stated in the introduction, the National Bureau of
Standards basic method for the simple barley-sugar test differs from
the Hooker candy test in the following details:
The boiling vessel is a 600-ml chemical-resistant glass beaker with
detachable thermometer support in place of a copper casserole with
no thermometer support.
The weight of sample is 250.00 g of sugar on a dry basis, instead of
% pound without reference to moisture content.
The water is added to make up to a total weight of 350.00 g, i.e., 100.00
g of total water, including the moisture in the sample, instead of 3 oz
(87 or 89 ml) of water by volume. This involves a decrease of about
2 percent in the ratio of sugar to water.
386 Circular of the National Bureau of Standards
The cooking interval starts at a standardized initial temperature of
30°C (86°F) instead of at a haphazard room temperature.
The duration of cooking is specified for reference conditions only
instead of for each individual test, and the interval is changed from
what amounts to 23 minutes +2 minutes to 20.00 minutes +20
seconds (for the reference conditions) and to whatever interval of time
results with reliably adjusted apparatus in the individual tests on the
unknown samples.
The form and arrangement of the burner are definitely specified instead
of being left to chance, and means are provided for attaining the
precision required.
The boiling vessel is covered at the moment the temperature of the
mixture reaches 70° C (158°F), with the sugar practically dissolved,
before, instead of after, boiling has commenced.
The vessel is uncovered at the instant the sirup has attained a tem-
perature of 120° C (248°F) instead of precisely 15 minutes after the
heating was started *.
Once the sugar is approacimately all dissolved and a temperature of
70° C (158°F) is attained, the thermometer remains fixed in the clasp
attached to the vessel throughout the remainder of the cooking
interval, with its bulb located at a definite place in the sirup where it is
least exposed to direct radiation from the vessel bottom immediately
above the flame, and at a place where the sirup is least superheated
and least subject to fluctuation of temperature. Hand stirring of
the uncovered boiling sirup is omitted.” No stirring rod is used at
any time.
The plaques are formed on a water-jacketed metallic slab which is
supplied with a steady current of water at a temperature of 25°C
(77°F), instead of on a simple sheet of copper which varies in tempera-
ture. This augments the uniformity of heat exposure to which the
different samples are subjected.
For the observation of certain variable properties of the samples, which
were not comprehended in the original Hooker candy test, the
National Bureau of Standards basic method provides special means.
Especially notable among these properties are the varying tendencies
of the samples to foam at the initial boiling, to “froth” later, to form
colored compounds in the test, and to slump or spread and yield
different specific areas in the formation of the plaque.
The specifications are planned for systematic modifications in the less
critical details to provide for the setting up of specialized procedures
meeting the requirements of various types of candy tests not considered
in the present discussion. The Hooker procedure was devised for a
very limited field of service.
(g) UTILITY AND RELIABILITY OF THE CANDY TESTS
Barley-sugar tests and the associated observations offer one of the
simplest and surest means of evaluating the quality of commercial
* This specification obviates the possibility that the sirup may become considerably supersaturated while
the vessel is still covered; thus it avoids danger of starting crystallization by the shock of uncovering the
yessel. . Moreover, when tests are operated on different cooking intervals (for which provision will be made
in specialized procedures not covered in the present discussion), they are placed on a more nearly uniform
basis in respect to the effects of uncovering when uncovering occurs at a uniform temperature instead of at a
uniform time from the start of heating [4].
80. It was shown as long ago as 1913–14 that hand stirring of the boiling sirup is a productive source of
Variability in the results obtained by different operators of the Hooker procedure [4].
Polarimetry, Saccharimetry, and the Sugars 387
white sugars. The Hooker procedure has proved adequate for verify-
ing the purification of the most highly refined commercial products
and for detecting gross faults of purification in products of ordinary
quality. Regardless of the classification of the product in trade, a
lot of sugar which consistently yields excellent barley sugar in the
Hooker test almost certainly will prove adequately refined for prac-
tically any manufacturing use. Conversely, a lot which repeatedly
yields poor results in this test assuredly contains inexpedient quan-
tities of impurities, either too little of certain favorable kinds or too
much of the deleterious kinds. Since impurities of the latter class
can impair the keeping qualities of the sugar as seriously as they affect
its suitability for manufacturing uses, candy tests have a much broader
field of usefulness than is comprised by the needs of the confectionery
industry alone. For many years certain progressive producers of
refined and direct-consumption sugars have used candy tests of various
kinds as a guide to the improvement of their wares, and as a means
of routine control in the daily maintenance of the particular quality
standards which each producer has set for his output. All too fre-
quently general consumers have overlooked the possibilities of the
candy tests, not merely as a means of inspecting their purchases or as
an instrument for comparing the different products offered, but also
as a basis upon which specifications can be definitely established prior
to purchase. Important disputes have arisen over the stability of
sugar in storage, as well as in manufacturing operations, which might
have been avoided through such specifications. Losses of sugar are
suffered by producers themselves, as well as by handlers and consum-
ers, in spoilage which could be forestalled through a more extensive
use of candy tests.
In the sugar and confectionery industries, two phases of the effects
of impurities upon the stability of sugar in candy tests commonly are
distinguished as the inversion, or hydrolysis, of sucrose and the
caramelization of the resulting mixture of sucrose, the products of
hydrolysis and certain other substances which may be present.
Caramelization is a phenomenon which comprises numerous complex
reactions resulting in the formation of colored compounds and other
substances which are deleterious to the quality of candy.” The types
of reaction which occur, and the velocities of the reactions (hence the
extent to which they progress during any individual test), are influenced
by the particular regime of conditions which obtains during the
operation of the test, not solely by the kinds and the amounts of
impurities present. Therefore, the arbitrary schedule of heat expos-
sure of the sample under arbitrary conditions of operation ought to be
specified within sufficiently narrow limits of variability to assure that
the resulting decomposition shall be practically proportional to the
reciprocal of the stability of the material. The quality of the sample *
finally is judged by an examination of the product of the test. While a
visual examination of the plaque may serve the more inexact purposes
31 Involved in both phases of the instability of the material are not only various decompositions and deg-
radations of sucrose and the products of hydrolysis, but also reactions comprising several types of chemical
synthesis, probably including reversions and polymerizations and possibly chemical combinations between
glucose and amino acids or between glucose and proteins in certain instances. The reactions are so numer-
ous and yet so generally interdependent and (with but slight alteration of conditions) so variable that their
chemistry and kinetics never have been cleared up, even for a single case.
3? Except those phases of the quality which are indicated by the appearance of the sirup while boiling.
Differences of quality are distinguishable by this method in only a limited number of samples. (See “foam
number”, p. 373.)
388 Circular of the National Bureau of Standards
of a candy test, any quantitative statement of the stability of the
sample must depend upon analytical procedure and other physical
measurements. Examples are the estimation of sucrose hydrolysis
(as by polarimetric or copper-reduction methods), the estimation of
caramelization (as by measurements of the color in the solid plaque
or in a water solution of the candy), and the estimation of the “slump,”
or specific area, all as outlined above.
Appraisal of the differences in the stability of the various samples,
and the separation of the samples accordingly into various classes, is
practicable only to the degree that the particular candy-test procedure
approximates a reliable reproduction of a constant program of operat-
ing conditions each time it is applied. This is to say that the varia-
bility among the programs established in numerous individual tests on
random samples of the same lot of sugar must result in much smaller
differences in decomposition (as distinguished by the chosen methods
of examination) than the variations in decomposition arising from the
differences in stability of the different lots of sugar that are to be sep-
arated on the basis of quality. The tolerances for deviation from a
constant program must be smaller the more precise the separations
are to be. On the other hand, the minimum tolerances which may be
imposed are limited by the character of the candy-test procedure
available.
The minimum feasible tolerances which may be stipulated for candy
tests according to the Hooker procedure are so great that satisfactory
separations of samples on a quality basis are impracticable. This is
doubly evident where different operators are involved, what with
inadequacy of directions as to arrangement of apparatus and what
with the inclusion of details of procedure which inherently are subject
to individual variability. No long array of samples could be arranged
precisely in the order of minutely graduated differences of stability,
nor could the degree of departure of a sample from an established
standard of quality be indicated, on the findings of candy tests carried
out by different operators by means of the Hooker procedure alone or
by means of any of its ordinary modifications. The deviations are so
great, indeed, that nearly every user of the test has entertained at least
transient doubts that the results obtained even by a single operator
are valid criteria for any useful separation of samples on a stability
basis [11, 12]. The circumstances are complicated by the failure of
many users to appreciate the fact that no finer separations should be
demanded than definitely will be put to practical use.
Very pure sucrose in candy tests is distinctly weak but relatively
stable in respect to caramelization. The purest commercial products
have similar characteristics in both respects. Because of this, certain
brands of “first-run” char-refined sugar, as produced for confectioners’
use, have been strengthened at the refinery for many years by the
addition of small quantities of sodium carbonate or sodium bicar-
bonate * to the water used for washing the crystals [5]. The small
amount of impurity thus deliberately introduced has but little in-
fluence upon the color of hard candy produced from the sugar, although
much excess of the alkali would bring about marked caramelization.
33 In 1897 Wiechmann presented data [1] on experimental suppression of sucrose hydrolysis by the presence
of 1 part of calcium oxide, sodium carbonate, or sodium bicarbonate, in 100,000 parts of refined cane sugar
during its conversion to barley sugar. Possibly even earlier, Hooker initiated the practice of strengthening
conſectioners' sugars, in response to the complaints of certain consumers. The treatment was devised and
originally controlled through the Hooker candy-test procedure.
Polarimetry, Saccharimetry, and the Sugars 389
The stability of refined cane sugar of ordinary quality is inferior to
that of the strengthened confectioners’ sugars in respect to both
hydrolysis and caramelization [5]. On the other hand, beet sugars
generally tend to be distinctly stronger than either type of cane sugar
but definitely less stable than either as to caramelization. There are
notable exceptions to these usual relations of the three types of sugar
mentioned. Indeed, the stability gradations of all sorts are so nearly
continuous that probably no one would propose to distinguish the
types of sugar to which many individual samples belong, solely on
the evidence of candy tests.
Because such gradations are continually encountered, most users
and prospective users of candy tests need a method which is both
more reliable and more precise than any of those heretofore available.
For selecting or for segregating different lots of sugar according to the
requirements of different consumers, without an excessive number of
tests, a high degree of reliability is demanded of the individual candy
test. For the precise control of quality in sugar production in any
plant with relatively little variation of stability in its products, the
candy test procedure should have a high degree of reproducibility to
permit stipulation of small tolerances of standard deviation. For
many other purposes, like precision must be attained. The method
and equipment described for the National Bureau of Standards
simple barley-sugar test procedure are designed to reduce the standard
deviations, as compared with those which prevail in the candy tests
heretofore available, (1) by diminishing the variations of practice
through more specific directions, (2) by diminishing the influence of
the operator's individual technique upon the procedure, and (3) by
greatly reducing instrumental variability in several important re-
spects. Providing these specifications are adhered to in detail both
as to operation and equipment, this enhancement of precision in
candy tests should be realized in fact. With attention to the order of
occurrence of stability variations in relation to the usual control and
operating data of a plant, as a clue to the presence or to the advent of
“assignable causes”, manufacturers can make use of the increased
precision as a means of bringing the production of sugar more definitely
within the field of statistical control as practiced in certain other
industries. The dependability and increased convenience of the new
procedure, once the equipment is installed, and as compared with what
heretofore has been available, should place the candy test on a much
surer footing from the viewpoint of the consumer as well as the
producer.
3. CONCLUSION
After quoting Hooker's directions for candy-test procedure for
comparison, directions for a new and greatly improved simple barley-
sugar test method are presented in detail, together with specifications
for the apparatus required for its use. It is proposed not only as a
standard method for the inspection of commercial sucrose with respect
to stability to heat, but also as a model procedure which with suitable
modification can be converted to various other types of candy tests
for the examination of all sorts of sugar products. Details of the latter
use are reserved for discussion in another place. It is pointed out that
the method as used for the examination of commercial sugar is of
value both to the producer who wishes to establish a more effective
390 Circular of the National Bureau of Standards
control of the quality of his product, and to the consumer who either
purchases sugar on quality specifications or allocates his purchases to
different uses according to their quality. The possibility has been
suggested of implementing the control of quality in the production of
sugar through the introduction of modern statistical methods which
make use of the order of occurrence of stability variations as a clue
to their assignable causes.
4. REFERENCES
| F. G. Wiechmann, J. Phys. Chem. 1, 69–74 (1897).
| S. J. Osborn, The Use of Beet Sugar in Candy-Making (1913), unpublished
report of the techincal staff of the Great Western Sugar Co., Denver, Colo.
| Cir. BS C44 [ed. 2] (1918).
| Max J. Proffitt, Laboratory Work in Connection with Experiments on the
Production of Candy Sugar (1914); Filtration Experiments (1916); un-
published reports of the technical staff of the Great Western Sugar Co.,
Denver, Colo.
Frederick W. Murphy, Candy Mfr. 1, [3] 36–37, 51 (1921).
H. S. Paine, M. S. Badollet, and J. C. Keane, Ind. Eng. Chem. 16, 1252–60
(1924).
J. A. Ambler, Mfg. Confectioner 7, [1] 17–19, 82 (1927).
G. L. Spencer and G. P. Meade, Handbook for Cane Sugar Manufacturers
and Their Chemists, p. 189–90 (John Wiley & Sons, New York, N. Y.,
1929).
9] J. A. Ambler and S. Byall, Ind. Eng. Chem., Anal. Ed. 7, 168-73 (1935).
º Otto Windt, Mfg. Confectioner 12, [8] 20–24 (1932).
1
2]
[5]
[6]
[7]
[8]
A. B. Kennedy, Mfg. Confectioner 13 [5] 18–23, 51 (1933).
| E. K. Ventre and S. Byall, Report of Studies on Uniformity of Quality
of Sugars, U. S. Dept. Agr. Bur. Chem. Soils (1938).
[13] Max J. Proffitt, Unpublished paper on candy test methods.
XXV. PREPARATION AND PURIFICATION OF PURE
SUGARS
1. DEXTROSE
With a view to assisting in the unification of methods of sugar
analysis, the National Bureau of Standards issues chemically pure
dextrose as one of its standard analyzed samples. This was first
issued in 1914. At that time, and for some years thereafter, the
method of purification and crystallization was that devised by
Jackson [1]. The raw material used was the purest form of commercial
dextrose obtainable at that time and was marketed under the trade
name of Cerelose.” It was a brownish-colored granular material
containing about 87.2 percent of dextrose, 3.9 percent of nonferment-
able sugars, 0.55 percent of ash, and a quantity of dextrins. The
method is as follows:
The impure material is submitted to a preliminary treatment similar
to that described by Bauer [2]. The crude material is digested in
a shaking machine with alcohol in order to wash the mother liquor
from the crystals. The mass is then poured into a centrifugal machine
and drained at high velocity. The drained crystals are then washed
repeatedly in the rotating basket with fresh portions of alcohol. The
washed substance is dissolved by heating in 40 percent of its weight
of water and 140 ml of alcohol added for each 100 g of the washed
substance. This mixture is then heated on a steam bath and filtered
to remove the precipitated impurities. The filtrate is evaporated in
* At the present time this name is applied to a highly purified commercial dextrose having the physical
appearance of granulated beet or cane sugar.
Polarimetry, Saccharimetry, and the Sugars 391
the vacuum boiling apparatus described on page 393 to about 60
percent of sugar. The supersaturated liquid is then transferred to a
shaking machine, a few crystals of dextrose hydrate added, and the
substance allowed to crystallize in motion. After standing overnight,
the crystal mass is centrifuged and washed four to five times with
redistilled alcohol. The crystals obtained are very white and already
possess a high purity. They are then dissolved in water, the solution
filtered through asbestos into the boiling apparatus, concentrated,
and recrystallized from the aqueous solution. The second crystals
are carefully dried and analyzed for moisture, ash, polarization, and
reducing power. If these tests indicate the presence of any remaining
impurity, the recrystallization is repeated until a satisfactory product
is obtained.
The crystals thus obtained are dextrose hydrate. Formerly in the
preparation of standard samples the hydrate was freed of its water
of hydration by heating in an electric oven at 60° to 70° C.
The above method of purification was followed for some years,
until there became available white crystalline dextrose in commercial
quantities. The following modification of the method of purification
was then adopted. A quantity of the white crystalline dextrose is
dissolved in hot water to make a 60 percent solution. This is treated
with char and filtered. The filtrate is concentrated in a glass boiling
apparatus under reduced pressure to a sirup of about 80 percent of
dextrose. The thick sirup, which is brought to a temperature of
55°C, is seeded with crystals of anhydrous dextrose and placed in a
rotating crystallizer enclosed in an insulated, electrically heated
cabinet held at 55° C. The crystallization is usually complete within
a few hours. The temperature is reduced until the massecuite has
reached the temperature of approximately 30°C, when the crystals
are separated on a centrifugal machine and washed with alcohol.
The crystallization is repeated until analysis shows the material to be
of the requisite purity. The air-dried crystals of anhydrous dextrose,
thus obtained, contain less than 0.1 percent of moisture. The material
is finally dried in vacuum desiccators containing suitable drying agents,
with or without the aid of heat, to a moisture content of 0.01 percent
or less. This purified material is issued as Standard Sample 41,
Dextrose.
In the preparation of pure dextrose hydrate the 60-percent solution,
which has been treated with decolorizing carbon and filtered as
described above, is seeded with crystals of dextrose hydrate and rotated
in the crystallizer at room temperature until crystallization is complete.
The crystals are centrifuged, washed with alcohol, and dried in the
usual manner.
The standard dextrose sample may be used as a standard in methods
for the determination of reducing sugars to replace the usual invert-
sugar solution and has the advantages of greater convenience in the
preparation of the solution and greater certainty of composition.
Some uncertainty arises in the preparation of invert-sugar Solutions
on account of the method of inversion employed. Reversion products
may be formed, or either levulose or dextrose injured by too prolonged
action of the acid. Furthermore, if the solution is preserved, decom-
position may occur if either acid or alkali is in excess. The standard
dextrose solution may be prepared very readily and conveniently as
392 Circular of the National Bureau of Standards
needed by weighing out the required amount of solid substance and
dissolving in the necessary volume of water.
2. SUCROSE
Most of the methods for the purification of sucrose which have
been described depend upon the use of alcohol as a precipitant.
Sucrose is almost insoluble in absolute alcohol, and its solubility in
alcohol-water mixtures diminishes very rapidly as the concentration
of alcohol increases.
(a) METHOD OF HERZFELD [3]
Prepare a cold, saturated, filtered, refined sugar solution and with
continual stirring add an equal volume of 96-percent alcohol. Filter
after 15 minutes, wash with ether, and dry in a water bath.
(b) METHOD OF HERLES
This method gives particular attention to the elimination of raffi-
nose. To exclude traces of raffinose, precipitate a cold, saturated,
filtered solution of refined sugar with alcohol, warm on a water bath
to 60°C, decant the solution, pour fresh alcohol on the precipitate,
warm while stirring, decant again, wash the sugar on a filter with
absolute alcohol, and dry in a thin layer on filter paper at 30° to 40°C.
On account of the well-known solubility of raffinose in methyl
alcohol, many operators have used this as a precipitant to insure the
removal of this impurity.
(c) METHOD OF THE INTERNATIONAL COMMISSION FOR UNIFORM METHODS OF
SUGAR ANALYSIS [4]
To prepare pure sugar, further purify the purest commercial sugar
in the following manner: Prepare a hot, saturated, aqueous solution,
precipitate the sugar with absolute ethyl alcohol, spin the sugar care-
fully in a small centrifugal machine, and wash in the latter with abso-
lute alcohol. Redissolve the sugar thus obtained in water, again
precipitate the saturated solution with alcohol, and wash as above.
Dry the second crop of crystals between blotting paper and preserve
in glass vessels for use. Determine the moisture still contained in the
sugar and take this into account when weighing the sugar which is to
be used.
(d) METHOD OF BATES AND JACKSON [5]
A method of purification has been developed at this Bureau in
which recrystallization from aqueous solution is utilized. The purest
granulated sugar of commerce is dissolved in an equal weight of water.
This relatively dilute solution is clarified from albumenoids and sus-
pended material by the addition of alumina cream which has been
carefully freed from soluble salts by continued washing and testing
the wash water with barium chloride. The solution of sugar is
filtered by pouring on large, fluted filters of hardened filter paper.
The filtered solution, which usually has the brilliancy of distilled
water, is boiled in a vacuum-distilling apparatus at a temperature not
exceeding 35° C until the concentration of the solution, which was
initially 50 percent, reaches 76 to 80 percent.
The requisites for a serviceable concentrator may be briefly sum-
marized as follows: (1) Cleanliness, (2) low boiling point, (3) large
capacity, and (4) filtration of entering sirup.
Polarimetry, Saccharimetry, and the Sugars 393
The concentrator is shown diagrammatically in figure 98. The
entire assembly, with the exception of the aluminum vessel, B, and
condensing coils, C, is of glass; and with the exception of the small
asbestos filter, the sirup never comes in contact with any other sub-
stance. The evacuating is done by a power-driven vacuum pump or
an aspirator connected at D. When it is desired to concentrate a
sugar sirup, the procedure is as follows: The solution, usually approx-
imately of 50 percent concentration, is placed in the flask, A, and the
entire system evacuated up to the cock, E. This cock is then care-
fully opened and the solution slowly driven through the asbestos
filter into the boiling flask, F, capacity 13 liters. Here it is gently
warmed by the water bath, and the temperature of the sirup noted on
the thermometer, G. In order to obtain any desired boiling point, it
ASBESTOS
FILTERS/ )
TO COMPRESSED AIR COCK —
TO HOUSE VACUUM COCK —
F1GURE 98.-Apparatus for concentrating sirups in vacuum.
is only necessary to regulate the pressure, as indicated by the mercury
gages H, H. The efficiency of the assembly is such that sirup is
rapidly brought to the desired concentration of about 80 percent at a
temperature below 32°C. This is made possible by the high efficiency
of the condensing system and by having all joints carefully ground to
fit. The stopcocks are lubricated with water or sugar sirup. The
condensing coils, C, are of copper, eight in number, connected in
parallel, and immersed in ice water. To prevent vapor reaching the
vaccum pump, the pipe, I, is joined to the base of the condenser. As
rapidly as the vapors condense they pass into vessel J and subse-
quently, by closing cock L and opening M, are expelled into K from
which the liquid is eventually driven into the waste. By noting the
|*. of this liquid, the concentration of the sirup in F is known at
all times.







394 Circular of the National Bureau of Standards
The question of size of crystals is of the first importance. In gen-
eral the smaller the crystals the less the “included solvent” or en-
trapped mother liquor. When the solution in the boiling flask, F, has
reached the desired concentration, the vacuum is broken at N and the
solution poured out to crystallize. Crystallization in general does
not begin in these pure solutions until they are seeded with a few fine
crystals of sugar. This is not done until after the solution is removed
from the boiling flask. Two methods of crystallization have been
tried. In the first the concentrated solution is transferred to a pre-
cipitation jar. It is then carefully stirred with a glass rod provided
with a glass shield. This procedure gives satisfactory results so far
as the control of the crystal growth is concerned, but it is laborious.
In the second, the liquid is transferred to a crystallizer, a cross section
of which is shown in figure 99. By this means it was found practicable
FLASK FOR
SUGAR SOLUTION
%
% ~2–2___2^2-2
Ear-Ezº-2-22
FIGURE 99.--Crystallizer.
to crystallize from a larger quantity of liquid and with no danger of
contamination. The device is very simple and consists of a hardwood
box mounted on bearings and driven by an electric motor. The
supports, A, A, which carry the container, are adjustable in order to
keep the center of gravity on the axis of rotation. The box is rotated
slowly so that the contents are subjected to a gentle and continuous
agitation.
The solid is separated from the mother liquor by a motor-driven
centrifugal machine. The centrifuge shown in cross section in figure
100 was built in cooperation with the Bureau, and has met all require-
ments. Its height over-all is 2 ft, and it requires but 4 square feet of
floor space. All the inside walls of the metal housing, in fact all surfaces
with which either the crystals or the mother liquor can come in contact,
are silver- or nickel-plated. The basket is carried on the end of the
vertical shaft of a three-fourths horsepower motor. It has an inside
diameter of 9% inches, and is capable of carrying 10 pounds of sugar.
Its heavy cover is held in place by a number of set screws, A, A, and

Polarimetry, Saccharimetry, and the Sugars 395
is readily removable in order to facilitate the removal of the centrifuged
material. The problem of a suitable lining has given considerable
trouble. To be satisfactory it must retain very small crystals, per-
mit free drainage of the mother liquor, and be able to stand the severe
strains incidental to high speeds. It is obvious that no single lining
is available that will meet all three requirements. A built-up lining
was accordingly resorted to. It consists of two layers. The outer
one is the regular copper centrifuge lining with elongated conical
holes. The inner one is of 200-mesh brass gauze. Both linings are
silver-plated.
In order to hold the flimsy gauze in place, it was necessary to fold
it over the edge of the heavy copper lining, both above and below, and
%
y
%N
|N
N.
SN
•'
***
(º
%
|: º;
ºº
t
2
%Z
*S
ź
|*
|
|
N
FIGURE 100.-Centrifuge.
also around the ends where the vertical edges meet, in every case
allowing it to overlap by 1 or 2 cm. At the junction of the two edges
an extra piece of gauze was fastened to close the crack. Inasmuch
as the wear on the gauze lining occurs at the top, it was protected by
a piece of thin copper tape which was bent into place. This combi-
nation has given excellent results. The mother liquor finds an outlet
through the drain, B. The small space left between the lid and the
frame was closed by stretching a rubber band tightly around the whole
machine.
It will be observed that when the centrifuge is in operation with
the hinged lid, C, closed, the contents of the basket, as well as the

396 Circular of the National Bureau of Standards
mother liquor, are safe from contamination by the air of the room.
The speed of rotation of the basket is controlled by a rheostat in
series with the motor.
In order to secure a proper distribution of the crystals and insure
smooth running of the basket, the crystal mass is introduced while the
machine is stationary or running at very low velocity. The speed is
gradually increased as the mother liquor runs off, until finally the
maximum speed of 3,000 revolutions per minute is attained.
The substance is then recrystallized in a similar manner, but a
second filtration is accomplished through the layer of asbestos in a
glass filter, shown in figure 98, connected directly to the boiling appa-
ratus which supplies the necessary vacuum. This asbestos filter
effectively removes the shreds of filter paper which are almost invaria-
bly in the filtrate after a filtration through paper. After the solution
has passed this filter, it comes in contact with nothing but clean glass,
and all manipulation of the solution or crystals is carried out under
glass cabinets, to reduce possible contamination with dust. The air-
dried crystals are powdered to dust in an agate mortar, of which the
pestle carries a shield to prevent contamination, and are placed in
a vacuum desiccator over lime.
(e) MODIFICATION OF METHOD OF BATES AND JACKSON [5]
A modification of the method of Bates and Jackson has been tried
at this Bureau. A 50 percent solution is clarified with alumina cream,
filtered and boiled below 35° C as described above. The boiling is
continued to a concentration of 70 to 73 percent of sugar. It is then
poured into a crystallizing jar and precipitated by the addition of an
equal volume of pure alcohol. The precipitate is separated centrif-
ugally, washed with alcohol, and air-dried. This process is repeated.
Before bottling, it is dried over lime in a vacuum.
The alcohol used for the precipitation of pure sugar should be highly
purified with respect to acids or aldehydes. It is not essential that it
be dry or free from other members of the alcohol group. The method
of purification described by Dunlap [6] meets these requirements.
Dissolve 1.5 g of silver nitrate in 3 ml of water, add to a liter of 95
percent alcohol in a glass-stoppered cylinder and shake. Dissolve 3
g of caustic potash in 10 ml of warm alcohol, and after cooling pour
slowly into the alcoholic AgNO3 solution. Do not shake. Allow to
stand overnight. Siphon off and distill.
(f) ANALYSIS
If sugar is to be used for the purpose of standardizing instruments,
its purity should be ascertained. This is particularly true of samples
required for polarimetric standards and for scientific data of all kinds.
There are many sorts of impurities whose presence, if undetected, may
lead to false conclusions in the interpretation of data. These impuri-
ties may be grouped into classes for the sake of convenience: (a)
Soluble inorganic impurities, (b) soluble organic impurities which
reduce alkaline copper, (c) soluble organic impurities which do not
reduce alkaline copper, and (d) moisture.
Inorganic impurities may readily be recognized by an ash deter-
mination. To perform this, a quantity of the sugar should be weighed
into a very carefully weighed platinum capsule and burned to a char.
Polarimetry, Saccharimetry, and the Sugars 397
The char should then be ignited in a muffle furnace at a low red heat,
properly below 550°C, until the carbon has been consumed. The ash
from a sample of properly purified sugar should not amount to 0.01
percent. It must be ascertained that the dish itself is of constant
weight during a similar period of heating. Samples prepared at this
Bureau have an ash content of less than 0.1 mg for a 5-g sample.
The estimation of very small quantities of reducing substances in
the presence of the very large quantity of sucrose requires the employ-
ment of special methods. The usual methods in which copper sulfate
is dissolved in caustic alkali are unsuitable because of the destructive
action of the reagent upon the sucrose.
Bates and Jackson [5] have made a detailed study of the reducing
action of pure sucrose on other alkaline copper reagents in which the
concentration of the hydroxyl ion was diminished. They found that
after several recrystallizations of the sucrose a minimum value for the
reduced cuprous oxide was obtained with each of the reagents investi-
gated, and that further recrystallizations failed to lower this value.
It appeared, therefore, that either a constant quantity of reducing
sugar was present, distributing itself in a constantratio between crystals
and mother liquor, or sucrose itself effected the slight reduction of the
copper. From this indirect method they concluded that if any reduc-
ing substance other than sucrose itself was present in their purified
samples it was of the order of 0.001 percent and entirely negligible for
most purposes. Of the several methods studied, Bates and Jackson
found a modification of the Soldaini method to yield the most satis-
factory results. The modified method is as follows:
Dissolve 297 g of KHCO3 and 1 g of CuSO4.5H2O in water and dilute
to 1 liter. The potassium bicarbonate should not contain much
K2CO3. Transfer 50 ml of this solution to a beaker, boil for 1 minute,
add a solution containing 10 g of the sugar, bring the whole to boiling,
and continue the boiling for exactly 2 minutes. At the end of this
period add 100 ml of cold, recently boiled distilled water and collect
the precipitate on a Gooch-Monroe crucible or on a very closely packed
asbestos mat. Under this procedure it has been shown that 10 g of
pure sucrose produces 1.1 mg of Cu2O, while each 0.01-percent im-
purity of reducing substance, estimated as invert sugar, increases this
precipitate by 1.9 mg.
Another method applicable to the estimation of very small quantities
of reducing sugars in pure sucrose is that of Ofner, see page 193.
The soluble organic impurities, which do not reduce alkaline copper,
are not so easily detected, but investigations at this Bureau have
shown that recrystallization from aqueous solution or by precipitation
with alcohol results, in every case examined, in a purification of the
sucrose. This fact can only be shown by a polarimetric study.
In order to dry pure, powdered sucrose, care should be exercised
not to subject the sample to a prolonged high temperature. Under
the influence of an elevated temperature, sucrose undergoes a decom-
position which is similar to a process of “caramelization.” In table 44
is given the time at each temperature required to form “caramel”
equivalent in reducing power to 0.01 percent of invert sugar. Caramel
can be detected by its reducing action on the alkaline copper solution.
Finely pulverized sugar can be dried at 70° C in a vacuum in 4 hours.
323414°–42 27
398 Circular of the National Bureau of Standards
The moisture remaining will in general amount to less than 0.003
percent.
TABLE 44.—Time required at various temperatures to form caramel equivalent to
0.01 percent of invert sugar
Temperature Time
oC FHours
79.5 (). 57
66.6 10. 9
50. 0 107.0
39.0 476. 0
3. LEVULOSE
(a) PREPARATION OF INULIN
Inulin can be prepared most satisfactorily from dahlia tubers, or
in somewhat lower yield from chicory, or in much lower yield from
jerusalem artichokes. The most suitable time for the extraction is
early autumn, but in the case of dahlias the large clumps of tubers
are usually divided for replanting in the late spring and the “blind”
tubers which are unsuitable for planting are then available for inulin
extraction. Even as late as early summer inulin can be obtained
from healthy tubers.
Comminute the tubers or roots in a food chopper or similar appli-
ance and express the juice with a tincture press, using, if necessary, a
small proportion of water to complete the extraction. Heat the juice
to 60° or 70° C and add milk of lime to about pH 8. Filter and adjust
the pH to 7.0 with oxalic acid. Heat to 70° to 80°C, add active
carbon, and filter. Allow the filtrate to stand quiescent overnight,
during which time the inulin separates in the form of small spheroids.
Slightly increased yields can be obtained by placing the filtrate in
a refrigerator and still greater yields by completely freezing it and
allowing it to thaw at low temperature. Filter the separated inulin
with suction and wash with abundant quantities of cold water.
The moist cake of inulin has at this point a dry-substance content
of 35 to 40 percent. It can be purified by dissolving in hot water
to a concentration of about 15 to 18 percent, treating with carbon, refil-
tering, and allowing to separate again by chilling. Filter and wash
with cold water.
For many purposes it is a satisfactory procedure to spread the moist
inulin cake on a glass plate and allow it to dry in air. When dried
in this way, it takes the form of hard hornlike masses which can be
pulverized readily in a mortar or ball mill. The air-dried substance
contains about 10 percent of water of hydration and a small quantity
of inorganic impurities. The latter can be diminished to negligible
proportions by repeating the processes of solution and chilling, or
by electrodialysis.
To avoid the formation of hornlike masses, the moist inulin cake
can be washed with 95 percent alcohol, followed by absolute alcohol.
The substance, however, has a tendency to retain alcohol [7], which
conceivably displaces in part the water of hydration.
A procedure described by Tollens and Elsner [8] is probably suitable
for less pure materials than fresh dahlia juices. The juice is expressed
Polarimetry, Saccharimetry, and the Sugars 399
in the presence of calcium carbonate, fermented at 25°C. with bakers'
yeast, defecated with lead acetate, and filtered. After removal of the
excess lead with hydrogen sulfide, the filtrate is frozen and thawed
to cause the separation of inulin.
Inulin crystallizes in the form of doubly refracting sphero-crystals
whose crystalline structure is indicated by X-ray patterns [9]. In
aqueous solution inulin has a specific rotation, ſolo = —39 to —40
referred to anhydrous substance.
If heated in glycerine, or glycol, or even in water solution and
precipitated from these solutions by alcohol, inulin occurs in a form
soluble in cold water [7, 10]. This soluble form is also produced by
the action of carbon dioxide [11].
(b) PREPARATION OF LEVULOSE
Levulose can be prepared from inulin, or invert sugar, or directly
from the expressed juices of inulin-bearing plants. The sugar can,
with some difficulty, be crystallized directly from hydrolyzed inulin,
but from the two latter sources it must, after hydrolysis, be isolated
by means of the insoluble calcium levulate, CaO.C.PI3O8.xH2O.
(1) HYDROLYZED INULIN.”—To 100 g of hydrated inulin add 400
g of water and agitate, preferably with a motor-driven stirrer, until
the inulin is “swollen” to a uniform paste. Heat to nearly boiling
and allow the inulin to dissolve completely, adding more water if
necessary. Reduce the temperature to 60° C and make the solution
0.08 N with sulfuric acid. Maintain the solution at 60° for 2%
hours, preferably following the hydrolysis by polariscopic observation
of samples withdrawn from time to time. Neutralize by agitating
vigorously with barium carbonate in excess or by cooling and titrating
to exact neutrality with barium hydroxide, preferably leaving the
solution very slightly acid (that is, acid to brom thymol blue). Filter
with carbon and evaporate in a vacuum to a thick sirup. Add
absolute alcohol and evaporate again to a sirup to remove the re-
maining water. Extract the sirup with several portions of hot
absolute alcohol. Allow the combined extracts to stand for 12 to
24 hours and decant the solution from the sirupy residue which forms.
Inoculate with levulose crystals and allow the crystallization to be-
come complete (usually within 2 or 3 days). The yield of sugar is
usually relatively small.
(2) PREPARATION OF INVERT SUGAR.—Dissolve 250 g of pure
cane sugar in 846 ml of water and heat to 70° C in a water bath.
Add 20 ml of 5 N hydrochloric acid, mix, and allow the solution to
remain at this temperature for 35 minutes. Cool and neutralize the
solution with dilute sodium hydroxide, avoiding local alkalinity.
The solution whose volume can be measured now contains 263.16 g
of invert sugar, one-half of which is levulose.
(3) HYDROLysis of PLANT JUICEs.-Juices extracted from inulin-
bearing plant tubers or roots contain from 12 to 20 percent of dry
substance depending upon the composition of the original juice and
upon the quantity of maceration or diffusion water used for extrac-
tion. The polysaccharides contained in the juice are hydrolyzed,
35 This method is essentially that of M. Hönig, S. T. Schubert, and L. Jesser [Monatsh. 8, 529 (1887)
9, 562 (1888); Ber. deut. chem. Ges. 20, 721R and 21,663R); and Wohl, [Ber. deut. chem. Ges. 23, 2084 (1890)]
but modified by the substitution of more definite directions for the hydrolysis of inulin [Jackson and Goergen,
BS J. Research 3, 29 (1929) RP79].
400 Circular of the National Bureau of Standards
preferably with sulfuric acid. It has been found impracticable to
supply exactly defined conditions for this hydrolysis, since varying
types of juice require variations of conditions. These variations
arise from the fact that the acid is in great part rendered inactive
by the buffering action of certain impurities in the juice. Even
when the pH of different types of juice is made apparently the same,
differences in the rate of hydrolysis occur. It is, therefore, necessary
to follow the hydrolysis by means of polariscopic or reducing-sugar
analysis of samples withdrawn from time to time. Typical hydrol-
ysis data are given in table 45, in which N is the normality of sulfuric
acid calculated from the amount of acid actually added; CHT, the
normality of hydrogen ion calculated from the pH measurement
(quinhydrone electrode); k, the velocity constant in terms of common
logarithms and minutes; and “time 99 percent,” the time required
for 99-percent hydrolysis.
TABLE 45.--IIydrolysis of plant juices
| | *
t; '--- To In- * | Time, 99
Brix N pH C. H-F perature k percent
–––. ------ - -
| | o C. Minutes
12.4 (). 2() 1. 578 (). ()264 73. 5 (). ()231 87
13. 7 . 25 1, 67() . 0214 72. () . () 143 14()
13. 7 . 18 2, 243 . ()057 72. () , ()0471 4.25
The last two measurements were made on the same juice, and it is
evident that the velocity is not proportional to the apparent hydrogen-
ion concentration, the explanation probably being that the pH meas-
urement is subject to errors caused by impurities in the juice. No
difficulty is encountered, however, if the hydrolysis is followed analyt-
ically. The time required for 99-percent hydrolysis can be diminished
at will by raising the temperature of reaction.
When the hydrolysis is complete, the solution is cooled to room
temperature or below and treated with milk of lime to pH 7 to 8 with
vigorous agitation and finally filtered.
The filtered juice is analyzed for total reducing sugar and levulose.
In precise work the Lane and Eynon titration and a method selective
for levulose are used (see p. 205). In approximate work, which is
satisfactory in most cases, the Lane and Eynon titration method
and the direct polarization are used (see the Mathews formula,
p. 223).
(4) PRECIPITATION OF CALCIUM ILEvu LATE [12].-Prepare a milk-
of-lime suspension, magnesia-free, of 18 to 20 percent calcium oxide
content and calculate the volume or weight required to contain an
amount of calcium oxide equal to 45 or 50 percent of the levulose in
the juice. Dilute either the juice or milk of lime so that when the
equivalent quantities are mixed, the levulose shall be approximately
6 percent of the total mixture.
The details of procedure for precipitating the calcium levulate have
been directed to the end of obtaining relatively large discrete crystals
rather than the fine interlacing needles produced in the original method
of Dubrunfaut. The precipitation preferably is made in a vessel
equipped with a motor-driven stirrer and immersed in a cold bath.
The following procedure illustrates the principal features of the
Polarimetry, Saccharimetry, and the Sugars 401
method and is subject to obvious variations with respect to details.
Transfer to the precipitation vessel about one-tenth of the total
quantity of milk-of-lime suspension and add one-tenth of the total
volume of sugar sirup, allowing the latter to run in at a slow regular
rate. It is advisable to examine the precipitate under the microscope
from time to time and ascertain that the calcium levulate has formed
discrete crystals. When properly prepared, they take the form of
elongated prisms. Add successively the remaining portions of milk
of lime, each being followed by the respective portion of sirup. Under
favorable conditions the levulate crystals will be 0.1 to 0.2 mm in length
and can be readily and rapidly separated from the waste water by
filtration methods.
The yield of levulose by this process is dependent upon many cir-
cumstances. In order to obtain high yields, the temperature of pre-
cipitation must be in the neighborhood of 0°C. Increased tempera-
ture causes a considerable diminution in the yield of levulose. Thus,
in a series of experiments on hydrolyzed artichoke juices, Jackson and
Mathews [13] obtained a recovery of 82.3 percent at 3.2° C. 76.2 at
10.7°C, and but 64.0 at 16.0°C.
Typical quantitative data on the precipitation of calcium levulate
from various juices are shown in table 46.
It will be observed that the “Total recovered” of each product
(lines 16, 22, and 28) approximates the amount taken in the reaction
mixture (lines 12, 18, and 24). The yield of levulose (line 33) varies
inversely as the solubility of calcium levulate in the juice. The solu-
bility of calcium levulate is greatly increased in the presence of non-
levulose sugars. Thus, in experiment 1, the levulate in the waste
water, expressed as levulose (line 13), is held in solution largely by
the dextrose. In the remaining experiments, it is dissolved both by
dextrose and by other nonlevulose sugars.
402 Circular of the National Bureau of Standards
TABLE 46.-Quantitative data on
Line Item
1 | EXperiment---------------------------------- 1 2 3
2 | Type of juice--------------------------------- Pure Sugars Artichokes Artichokes
3 | Temperature of reaction (• C) - - - - - - - - - - - - - - - - 0.0 1.0 1.5
4 | Weight of products, grams:
5 Reaction mixture------------------------- 1,811 1, 554 1, 715
6 Waste Water----------------- ------------ 1, 199 934 1, 12
7 Wash------------------------------------- 724 731 676
8 Levulate cake- - - - - - - - - - - - - - - - - - - - - - - - - - - - 426 444 349
9 Wash water-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - (538) (555) 433
10 | Product balances:
11 LevuloSe: % g O g g
12 Reaction mixture--- - - - - - - - - - - - - - - - - - - 5. 38 97.4 8. 12 126. 1 6 106.3
13 Waste Water-------------------------- 0.23 2.8 1.04 9. 7 0.91 10. 2
14 aSD--------------------------------- 23 1. 7 0.71 5.2 . 65 4.4
15 Levulate cake- - - - - - - - - - - - - - - - - - - - - - - - 21.84 93.0 24. 10 107.0 26. 58 92.8
16 Total recovered - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 97.5 | - - - - - - - - 121.9 |-------- 107.4
17 Total reducing sugar:
18 Reaction mixture--- - - - - - - - - - - - - - - - - - - 6. 55 118.6 10. 42 161. 9 6.82 117. 0
19 Waste Water-------------------------- 1. 56 18, 7 3. 70 34.6 2.02 22.7
20 Wash--------------------------------- I . IO 7. 9 2. 19 16. 0 1. 32 8.9
21 Levulate cake- - - - - - - - - - - - - - - - - - - - - - - - 21.84 93.0 24. 10 107.0 26. 58 92.8
22 Total recovered.---- - - - - - - - - - - - - - - - - - - - - - - - - - - 119.6 || -------- 157.6 |-------- 124.4
23 Total CaO :
24 Reaction mixture - - - - - - - - - - - - - - - - - - - - 2. 53 45. 7 3.45 53. 6 3. 66 62. 9
25 Waste water---- - - - - - - - - -- ~~ *- - - - - sº - - - - - - 0.37 4.4 1.01 9. 4 0.69 7.7
26 Wash--------------------------------- . 30 2. 2 0.62 4. 5 .47 3.2
27 Levulate cake- - - - - - - - - - - - - - - - - - - - - - - - 9. O8 38. 7 8. 70 38. 6 14. 75 51. 5
28 Total recovered----------------. ------|-- - - - - - 45.3 |- - - - - - - - 52.5 ! -------- 62. 4
29 || Ratio, levulose to total reducing sugar:
30 Reaction mixture------------------------- 0. 822 0.779 0.910
31 Waste water------------------------------ . 150 . 281 . 448
32 Wash------------------------------------ . 209 . 325 . 494
33 | Yield of levulose, percent--- - - - - - - - - - - - - - - - - - - 95. 5 84.8 87, 3
34 || CaO required (theoretical), grams - - - - - - - - - - - - 35. 5 47.2 43.4
35 | CaO used, grams-------------------- - - - - - - - - - 45. 7 53. 6 62.9
36 || Ratio, CaO to reducing sugar in waste water--- 0.235 0.272 0.339
Polarimetry, Saccharimetry, and the Sugars 403
calcium levulate precipitation
Line
4 5 6 7 8 9 I
Artichokes Artichokes Chicory Dahlias Artichokes Artichokes 2
3.0 0. 5 3.0 0.8 10 9. 5 3
4
1, 735 1,448 1,644 1, 549 1, 566 1,838 5
1, 170 849 993 770 1,050 1, 234 6
705 795 702 675 589 605 7
382 406 462 592 394 387 8
(522) 600 (513) 488 472 400 9
10
% g % g % g % g O g O g 11
5. 88 102.0 5, 60 81.2 7. 04 115. 7 8. 92 138.2 6.01 94.2 5.94 109. 1 12
0. 73 8. 5 0. 58 4.9 0.84 8.4 0. 56 4. 3 1.25 13. 1 1. 17 14.4 13
.47 3.3 .45 3. 6 . 69 4.8 . 49 3.3 0.86 5. 1 0.85 5. 1 14
23.5 89.6 17.71 72. 0 || 21.90 101.2 22.02 130.4 19. 29 76. 0 22, 80 88. 2 15
- - - - - - - 101.4 |- - - - - - - 80. 5 || -- - - - - - || 114. 4 | . . .----| 138.0 |- - - - - - - - 94.2 |- - - - - - - - || 107.7 #
6.80 118.0 6. 40 92.8 8. 02 131.8 9. 55 147. 9 8. 29 129.9 6.92 127. 1 18
1. 67 19. 5 1. 52 12.9 1. 88 18. 7 1. 20 9, 3 3. 55 37. 3 2. 23 27. 5 19
1. 08 7.6 1.00 7. 9 1. 39 9.8 1.02 6.9 2 13.8 1.77 10. 7 20
23. 5 89.6 || 17.71 72. 0 || 21.90 101. 2 22, 02 130, 4 19. 29 76. 0 22.80 88. 2 21
* * * * * * * 116. 7 |- - - - - - - 92.8 || -- - - - - - | 129. 7 || -- - - - - - || 146.6 |- - - - - - - - | 127. 1 |--------| 126.4 %
2. 71 47. 1 3. 71 53.7 3. 23 53. 0 4. 00 62. 0 3. 37 52.7 3. 51 64. 6 24
0. 73 8. 5 0. 58 4.9 0.67 6, 6 0, 62 4.7 1.01 10.6 0.68 8.4 25
. 49 3.5 .40 3.2 51 3. 6 51 3.5 0.71 4. 2 . 51 3. 1 26
9.00 34.4 || 11.40 46. 3 9. O0 41.6 9.06 53. 6 10. 1 39.8 13.00 50, 5 27
- - - - - - - 46.4 |------- 54. 4 |- - - - - - - 51.8 |- - - - - - - 61.8 |-------- 54.6 |-------- 62. 0 28
29
0.864 0.874 0.878 0.935 0.725 0.858 30
. 439 . 384 . 448 . 424 . 352 . 522 31
439 . 450 . 493 . 487 . 369 . 48 32
87.8 88. 7 87.5 94.3 80. 7 80. 7 33
39.9 30.5 41. 7 48. 7 38.4 38.9 34
47. 1 53.7 53.0 62. 0 52.7 64. 6 35
0.438 0.383 0.356 0. 511 0.285 0.304 36
404 Circular of the National Bureau of Standards -
Dextrose alone at 0°C holds in solution about one-fifth of its weight
of levulose (in the form of levulate). Other nonlevulose sugars are
derived from inulin, which upon acid hydrolysis yields, in addition to
about 92 percent of levulose, 3 percent of dextrose and about 5 percent
of a group of nonreducing difructose anhydrides [14]. It is due mainly
to these latter substances that the waste water (line 13) from the plant
juices contains so much more levulose than that from the mixture of
pure sugars. Other nonlevulose sugars may be derived from too
prolonged hydrolysis of the juices, which causes the formation of the
levulosans described by Pictet and Chavan [15], or from a too alkaline
medium for defecation, which may cause the Lobry de Bruyn-van
Ekenstein transformation.
Table 46 shows in general the compositions of products and by-
products which would probably be found in a levulose plant of any
magnitude.
The levulate cake, which contains in average about 22 percent of
levulose and 10 percent of calcium oxide, is carbonated by adding it
in small portions to a violently agitated quantity of cold water into
which carbon dioxide is passed, preferably by some device such as the
Doherty carbonator [16] which disperses the gas into a fine state of
division. Carbonation is continued until the solution is slightly acid
to phenolphthalein. The mixture at this point necessarily contains a
considerable quantity of calcium bicarbonate which requires neu-
tralization, since, if carried into the filtrate from the calcium carbonate,
it would be decomposed during the subsequent evaporation by vola-
tilization of carbon dioxide. When calcium bicarbonate is decomposed
in this manner, it imparts a pH of 8 to 9 to the levulose solution.
This alkalinity at the temperature of evaporation impairs the sugar
seriously.
The most satisfactory method of neutralizing calcium bicarbonate is
to add a thin suspension of milk of lime or calcium levulate until a
minimum electrical conductivity is reached. The calcium carbonate,
which at the low temperature sometimes crystallizes with six molecules
of water of crystallization, is filtered and washed. The filtrate is now
slightly alkaline, being saturated with calcium (and if present, mag-
nesium) carbonate. It is again adjusted to a minimum electrical
conductivity by addition of dilute oxalic acid.
The filtrate is evaporated at reduced pressure to a sirup. At some
point during the evaporation there usually occurs a separation of
inorganic salts, which are removed by filtration with 1 or 2 percent of
active carbon. The resulting solution should have a levulose purity
in excess of 99 percent, being contaminated mainly by inorganic salts
in which magnesia usually predominates.
(5) CRYSTALLIZATION OF LEVULOSE,--Crystallization of the sugar
can be conducted in aqueous or in aqueous alcoholic solution. For
laboratory preparations, aqueous alcohol is the more convenient sol-
vent. The solution is evaporated to a sirup and crystallized, after
seeding, under the conditions illustrated in table 47. These conditions
of course may be considerably varied.
Polarimetry, Saccharimetry, and the Sugars 405
TABLE 47.-Recrystallization of levulose from alcoholic solution
* * º Strength Weight Yield of dry crystals
n%; thick sirup Levulose | Weight weight Qí alºo. of ai.
D of Sirup of levu- hol (by hol
lose Volume) Weight | Percent
Percent g g Percent g g
1,508---------------------------- 89. 2 897 800 95 346 482 60
1.508---------------------------- 89.2 1,078 962 100 353 735 76
1.5133.-------------------------- 91.3 359 328 95 144 211 (54
Crystallization is accomplished in a crystallizer or in a tumbling ma-
chine or any apparatus which keeps the crystallizing mass in slow
continuous motion. Frequently the addition of alcohol causes a
separation into two liquid layers which, however, coalesce as crys-
tallization progresses. The crystals are separated on a Büchner
º º by centrifugal drainage and thoroughly washed with 95-percent
alcohol.
For the preparation of levulose of highest purity the substance can
be recrystallized in the same manner. It sometimes occurs that the
inorganic impurities persist. These can be removed by determining
the ash content and, considering it as calcium carbonate, adding the
stoichiometric equivalent of nitric acid. In this case the final washing
with alcohol must be very thorough.
Levulose can also be crystallized from aqueous solution in spite of
its high solubility in water. The solution is evaporated at diminished
pressure to about 90 percent of solids, placed in a crystallizer at 50° to
55°C, seeded with crystals, and allowed to crystallize in slow motion
by letting the temperature drop very gradually over a period of 1 to 3
or 4 days, depending upon the purity of the solution and the rate of
growth of the crystals.
4. REFERENCES
| F. J. Bates and R. F. Jackson, Bul. BS 13, 633 (1916) S293.
| H. F. Bauer, Orig. Comm. 8th Int. Cong. App. Chem. 13, p. 21 (1912).
| E. O. von Lippmann, Die Chemie der Zuckerarten 2, 1051 (F. Vieweg & Sohn
Braunschweig, 1904).
| This Circular (p. 768).
| F. J. Bates and R. F. Jackson, Bul. BS 13, 67 (1916) S268.
5] F. L. Dunlap, J. Am. Chem. Soc. 28, 397 (1906).
] E. Berner, Ber. deut. chem. Ges. 64, 842 (1931).
| B. Tollens V. H. Elsner, Kurzes Handbuch der Kohlenhydrate (J. A. Barth,
Leipzig, 1935).
9] J. R. Katz and A. Weidinger, Rec. trav. chim. 50, 1133 (1931). J. R. Katz
and J. C. Derksen, Rec. trav. chim. 50, 248 (1931).
[10] H. Pringsheim, Ber. deut. chem. Ges. 62, 2378 (1929); 63, 2636 (1930).
H. Vogel, Ber. deut. chem. Ges. 62, 2980 (1929).
. D. K. Drew and W. N. Haworth, J. Chem. Soc. 1928, 2690.
s: Jackson, C. G. Silsbee, and M. J. Proffitt, BS Sci. Pap. 20, 587 (1926)
519.
. F. Jackson and J. A. Mathews, J. Research NBS 15, 341 (1935) RP832.
. F. Jackson and S. M. Goergen, BS J. Research 3, 27 (1929) RP79. R. F.
Jackson and E. J. McDonald, BS J. Research 6, 709 (1931) RP299.
. Pictet and J. Chavan, Helv. Chim. Acta 9, 809 (1926).
H
R
R
R
A
E. P. Clark, BS Sci. Pap. 17, 608 (1922) S432.
406 Circular of the National Bureau of Standards
XXVI. PURITY
1. CALCULATION
The “coefficient of purity” is the percentage of sucrose in the solids
or dry substance of a sugar product and may be expressed by the
formula
_percent sucrose
Purity= percent solids X 100 (131)
It is also known as the “purity quotient” or more generally as the
“purity.” If accurate methods are used in the determinations, such
as the Clerget for sucrose, and drying for solids, the above ratio is
known as the “true purity.” This value is used in special research
and for purposes of checking or comparing products at different
stages of manufacture and should always be recorded and referred to
as true purity.
Of more general use for purposes of process control in individual
factories is the “apparent purity,” the value of which is found by
dividing the direct polarization of the product in solution by the
degrees Brix and multiplying the quotient by 100. Although the
apparent purity is only an approximation, it is of great value for
comparative purposes because of the rapidity with which the determi-
nations may be made. It is important, therefore, that the analyses
for each type of product be performed in exactly the same manner.
The procedure for apparent purity is applied directly to raw or thin
juices without weighing or measuring. Solids or massecuites must
be dissolved and thick liquors diluted. The solution is diluted with
water to a convenient density between 12 and 20 Brix, thoroughly
mixed, and allowed to stand in the cylinder until all air has escaped.
The removal of air bubbles may be hastened by connecting the cylin-
der to suction by means of a one-hole stopper and suitable tubing.
The degrees Brix is then read using standard hydrometers and ther-
mometers, the reading being corrected to 20° C.
To a portion of the solution (150 to 200 ml) roughly measured, a
sufficient amount of anhydrous basic lead acetate is added to clarify.
About a teaspoonful of dry diatomaceous earth is added and the
whole is thoroughly mixed, and filtered on a rapid filter paper. The
clear filtrate may be polarized directly in a 200-mm tube or, if it is
deeply colored, in a 100-mm tube. In cane products, varying amounts
of invert sugar are present and the negative rotation of the levulose
constituent is reduced by the presence of basic lead acetate. The
positive rotation of the dextrose is not thus affected, so that the net
result is a plus error in rotation.
When the amount of invert sugar is high, the effect of the excess
lead may be obviated in either of two ways: (1) After addition of the
dry lead salt and shaking, dry powdered oxalic acid is added, a little
at a time, until the leaded solution is faintly acid to litmus. The
whole is then thoroughly mixed and filtered. The clear filtrate is
polarized as above. (2) The filtrate from the solution treated with
lead alone (100 ml in a 110-ml flask) is treated with dilute acetic acid
until the reaction of the solution to litmus paper is slightly acid.
Dilution to the 110-ml mark is completed with water, and the solu-
tion is mixed and polarized. The polarization is corrected by adding
one-tenth of the observed reading.
Polarimetry, Saccharimetry, and the Sugars 407
In beet products little or no invert sugar is normally present. A
solution of basic lead acetate (sp gr 1.25, 20°/20°) is commonly used
for clarification instead of the dry salt. To 100 ml of the solution
(after determining the Brix) contained in a 100–110 ml flask is
added the proper amount of lead solution from a burette. The solu-
tion is mixed, a drop or two of ether being added to the flask to dis-
perse the foam, if present, and the volume is completed to 110 ml with
water. The solution is then filtered and polarized and the reading
corrected by the addition of one-tenth of its observed value.
The apparent purity of a sugar solution may be calculated by means
of the formula
Apparent purity=Factor X direct polarization. (132)
A formula for obtaining the “factor” to be used in the second term
of the above equation was originally elaborated by Cassamajor and
was based upon the Mohr cubic centimeter at 17.5°C and the normal
weight, 26.048 g. An equation based upon the modern units, milli-
liters at 20°C and the normal weight of 26.00 g as published by
Osborne [1], was derived as follows:
Let
D = true sp gr of solution at 20°/20° (table 109).
D'-apparent sp gr of solution at 20°/20° (table 114, p. 632).
B = degrees Brix of solution, then
D’= D+0.001 (D–1).
26.00×100×1.1 28.680
99.72×BD” TBD’
This equation includes the correction for one-tenth dilution and by
its use a table of factors was calculated for each 0.1 Brix from 0 to 25,
which may be applied in eq 132.
The formula of Rice [2] omits the one-tenth dilution factor and is
expressed as follows:
Factor= (133)
26.00X 100 o
99.718Ysp grx Brix
By means of this equation, Rice calculated a table of factors in incre-
ments of 0.1 extending from 0 to 25 Brix. This table (table 146,
p. 702) may be used for calculating apparent purity from experi-
mental values of the Brix and polarization.
A convenient table of purity values, expanded from Horne's table
as calculated by means of Rice's equation 134 is given by Meade [3].
Here the purity may be read directly from the Brix and polarization
of the solution. This table is arranged in intervals of 0.2° S from
polarization equals 15 to polarization equals 87.0.
It has already been pointed out that in the determination of “true
purity” the sucrose is obtained by the Clerget method and the solids
by drying, while in the determination of “apparent purity” the direct
polarization and Brix are employed. The above methods are the
ones in general use.
However, it is occasionally convenient to use the values for solids
obtained from the refractive index in conjunction with either the
percentage of sucrose or the polarization. Thus, there are six possible
combinations. Noel Deerr [4] suggests the use of the terms “true
Factor= (134)
408 Circular of the National Bureau of Standards
} } { { y y
purity,” “gravity purity,” and “refractive purity,” when the per-
centage of sucrose is used as the numerator of eq 131, and solids by
drying, by Brix spindle, or by refractometer, respectively, as the
denominator. If the polarization is used as the numerator, the
terms are qualified by the expression “polarization.”
2. REFERENCES
[1] S. J. Osborne, Methods of Analysis, p. 214 (The Great Western Sugar Co.,
Denver, Colo. 1920).
[2] E. W. Rice, Facts About Sugar 22, 1066 (1927).
[3] G. L. Spencer and G. P. Meade, Cane Sugar Handbook, p. 494–551 (John
Wiley & Sons, Inc., New York, N. Y., 1929).
[4] Noel Deerr, Cane Sugar, p. 492 (Norman Rodger, London, 1921).
XXVII. PACKING OF SUCROSE [1, 2, 3]
1. INTRODUCTION
The volume occupied by a given weight of sugar is a matter of im-
portance, both in relation to the operation of the centrifugal station
and the bagging of the sugar. It is the sum of the volumes of the
actual crystals and of the voids between them, and depends on their
size and shape as well as on the way in which they are packed together.
A study of the physical factors involved in the packing of sugar has
been made by Drinnen [1]. His results are also valuable in that they
indicate the way to an improved technique, which is desirable for
further study of the problem.
2. CRYSTAL DIMENSION
Sugar crystals were classified into various fractions in accordance
with their size, using a set of standard Tyler sieves. The dimensions
of the sieved fractions were estimated under the microscope by an
eyepiece micrometer. Since the smallest dimension largely deter-
mines the sieve in which the crystal remains, this dimension should
be the reference size for crystal measurements, provided that the
crystals do not depart very greatly from the cubical shape. In table
48 are shown the results from the examination of 50 crystals from each
sieve fraction.
TABLE 48.-Crystal size as related to sieve mesh

Meshes per | Sieve open- Average ‘...." Meshes per | Sieve Open- | Average ‘.
inch ings grain size (measured) inch ings grain size (measured)
77,770, 77,771. 77,770. 71071, 77,770, 77,770.
14------------ 1. 168 1. 41 1. 83}{1.47 || 35- - - - - - - - - - - - . 417 . 50 0.70)× 0.58
20------------ 0.833 1.00 1. 14)(0.98 || 48_ _ _ _ _ _ _ _ _ _ _ _ . 295 . 36 0.40X0.40
29------------ . 589 0.71 1. 01X0.83
3. VOLUME OF CRYSTALS AND VOIDS
Two methods were used for this determination, (a) displacing the
volume of air in a known weight of the sugar by means of a liquid in
which sugar is insoluble and measuring the volume, and (b) weighing
a known volume of sugar and calculating the volume of the crystals
from the weight and specific gravity of the sugar. The former appears
Polarimetry, Saccharimetry, and the Sugars
409
to be the more accurate method.
tained are shown in table 49.
Average percentage figures ob-
TABLE 49.-Volume of sucrose crystals and of interstitial voids as related to sieve
mesh size
Method (a) Method (b) Method (a) Method (b)
Sieve ºnes Sieve meshes
per Inc Crys- * Crys- v.; per inch Crys- e Crys- e
tºis | Voids this Voids tº Voids tº Voids
Percent | Percent| Percemt| Percent Percent| Percent| Percemt| Perrent
14--------------- 56. 44. 0 56.9 43. 1 36--------------- 64. 6 35.4 65.3 34. 7
20--------------- 60.4 39.6 62. 9 37. 1 || 48-- - - - - - - - - - - - - - 63.4 36. 6 66. I 33.9
28--------------- 63. 3 36. 7 65. 1 34.9 || Over 48- - - - - - - - - 62. 4 37.6 66.5 33. 5
4. WEIGHT OF CRYSTALS
Grain counts were taken for the various fractions on oven-dried
sugar, per gram from each fraction, as follows:
TABLE 50.-Weight of crystals in relation to average grain size (screen fractions)
Average Crystal Crystals | Weight per Average Crystal Crystals | Weight per
grain size dimensions per gram crystal grain size | dimensions | per gram Crystal
|
Tº 770, 77,777. Tng 77,777. 77,777. Tng
1. 41 1. 83}× 1.47 303 3. 30 . 50 0.70X0. 58 4, 301 . 23
1. ()() 1. 14)(0.98 1,070 1. 07 . 36 , 49)(0.41 15,057 . 70
0.71 1. ()2X0.83 2, 379 0.42
5. AREA OF THE CRYSTALS
This is a very difficult matter to estimate, and the findings of Pellet,
summarized by Thieme [3], are given in table 51.
TABLE 51.-Relation between weight and surface area of crystals for various crystal
sizes (screen fractions)

Weight per Y Surface: Weight per Tº # Surface:
crystal Surface area weight Crystal Surface area weight
7ng 7m m2 7mg/ 7mºm?
3. 28 8. 168 2. 29 . 30 1. 353 4. 51
1. 56 5. 136 3.49 ... 101 0.658 6. 51
0.64 2. 578 4. 01 . 057 .467. 8. 15
6. REFERENCES
[1] L. Drinnen, Proc. Queensland Soc. Sugar Cane Tech., 9th Conference, 1938,
99–202.
[2] Technical Communication No. 7, Bureau of Sugar Experiment Stations,
Brisbane, Australia, 1938.
[3] J. G. Thieme, Studies on Sugar Boiling, translated by O. W. Willcox, p. 26–27
(Facts About Sugar, New York, N. Y., 1928).
PART 3. PREPARATION AND PROPERTIES OF THE
SUGARS AND THEIR DERIVATIVES
XXVIII. OPTICAL ACTIVITY, CONFIGURATION, AND
STRUCTURE IN THE SUGAR GROUP
1. CONSTITUTION OF THE SUGARS AND THEIR
INTERRELATIONSHIPS
At the dawn of history our aboriginal ancestors were familiar with
honey and the sweet exudations of various trees and plants, but the
chemistry of the sugars did not begin until the introduction of cane
sugar into Europe [1]. With the expansion and development of
Europe, the need was felt for a sugar-bearing plant which could be
grown in a temperate climate. In the course of the search for a
source of sugar, attention was directed to many closely related natural
products. Thus, in 1792 Lowitz [2] found that starch on hydrolysis
gives a sweet substance, now known as d-glucose or dextrose. Many
other natural products were found which, on hydrolysis, gave closely
related products. These substances, with few exceptions, contain
carbon, hydrogen, and oxygen, in the proportions corresponding to
a hydrate of carbon, and hence they were named “carbohydrates.”
The carbohydrates comprise the sugars and the polysaccharides.
The polysaccharides are compounds which, by hydrolysis, yield sugars.
The sugars are classified as simple sugars or monosaccharides, and
compound sugars comprising the disaccharides, trisaccharides, and
tetrasaccharides. The simple sugars are classified further as trioses,
tetroses, pentoses, methylpentoses, hexoses, heptoses, etc., according
to the number of carbon atoms in the sugar molecule. The hexoses,
pentoses, and methylpentoses occur in many plant products and
play important roles in many biological processes. The two most
important simple sugars are dextrose and levulose. +
Few organic compounds have been studied as intensively as the
hexoses, and in particular, dextrose. This substance was known in
ancient times as grape sugar, but was not isolated from starch until
1792. It was found in diabetic urine in 1815 by Chevreul [3], and
in cellulose in 1819 by Braconnot [4]. Crystalline dextrose, however,
did not find wide use until a successful method for the production
of the hard refined crystalline sugar was devised at the National
Bureau of Standards [5]. This method in its essential principles
was applied commercially, and many millions of pounds of white
crystalline dextrose are now produced annually.
During the latter half of the nineteenth century many organic
chemists devoted their attention to the study of dextrose. In 1843
Dumas [6] ascertained that dextrose has the empirical formula CH2O,
and in 1870 Baeyer [7] advanced the structural formula
CH3(OH). CH(OH). CH(OH). CH(OH). CH(OH). CHO.
6 5 4 3 2 1
411
412 Circular of the National Bureau of Standards
This formula was supported by subsequent molecular-weight deter-
minations [8] and by the following chemical reactions: (1) The sugar
yields, on oxidation with bromine water or nitric acid, a monocar
boxylic acid (gluconic) which contains the same number of carbon
atoms as the parent sugar [9],
CH,OH(CHOH),CHO-H Brº-H H,0–CH,OH(CHOH),COOH-i-2HBr
(gluconic acid)
This proves that the aldehyde or potential aldehyde group lies at
one end of the carbon chain. (2) On reduction with sodium amalgam,
the sugar yields a hexahydric alcohol [10] (sorbitol),
CH,OH (CHOH),CHO-H Hº-CH2OH (CHOH),CH2OH.
(sorbitol)
(3) Reduction of the sugar with hydriodic acid gives normal hexyl
iodide, which proves that the carbon atoms are combined in a straight
chain. (4) The sugar combines with hydrogen cyanide to give a
nitrile, which, after saponification and reduction with hydriodic
acid, yields a normal heptanoic acid,
H
CH3OH (CHOH), CHO + HCN-CH2OH (CHOH)4C-CN-CH3(CH3)3COOH
OH
(normal heptanoic
acid)
This confirms the straight-chain formula and shows the presence of
an aldehyde or potential aldehyde group [11]. (5) The sugar yields
pentaacetyl and other derivatives, indicating the presence of five
hydroxyl groups. (6) Treatment with phenylhydrazine gives glucose
phenylhydrazone,
CH2(OH). CH (OH). CH(OH). CH(OH). CH (OH). CH=N–NHC, H,
and prolonged action gives glucosazone,
H
|
CH2OH.CH(OH). CH(OH). CH(OH) g- C=NNHCHs.
N–NHC.H.
The formation of hydrazones is typical of carbonyl compounds, and
the formation of Osazones is peculiar to alpha hydroxy aldehydes
and ketones. Although these properties support the polyhydroxy
aldehydic formula, other properties which will be considered later
show that the aldehyde modification is only one of the several tau-
tomeric forms which are characteristic of the sugars. Indeed, the
crystalline sugars contain lactol ring structures, and even in solution
the quantity of the free aldehyde modification is extremely small.
While the chemistry of dextrose was being developed, a number of
other sugars were being investigated. Some of these resemble
dextrose in that on oxidation they give acids containing the same
number of carbon atoms, whereas others give acids containing fewer
carbon atoms. The most important of the latter group is d-fructose
Polarimetry, Saccharimetry, and the Sugars 413
or levulose, which has the same molecular weight as dextrose but
differs fundamentally in that the reducing group lies on the second
carbon. One modification of levulose can be represented by the
formula:
choºchon choºchomº-chon
6 5 4 3 2 1
This structure is supported by the following evidence: (1) The
Sugar exhibits the reducing properties characteristic of a carbonyl
group, but on oxidation with nitric acid the carbon chain is broken to
give tartaric and oxalic acids,
choicnonononchongchon iso-
- O
COOH.CHOH.CHOH.COOH + COOH.COOH.
This is evidence that the reducing group lies on either carbon 2 or
carbon 3. (2) Reduction with sodium amalgam yields two hexahy-
dric alcohols, “sorbitol” and “mannitol,”
on
chong-g-g-gonon
2.
H H OH / OH OH H OH
| | | • r\rks :
clong -- g - g-g-choi Rº (sorbitol)
| |
OH OH H () H H OH ().H
N | |
CH2OH.C – C – C – C. CH2OH.
| | | |
OH OH. H. H.
(mannitol)
The formation of these two products shows that the carbonyl is not on
the end of the carbon chain, and the formation of sorbitol from both
dextrose and levulose shows that the two sugars are alike except for the
groups attached to carbons 1 and 2. (3) Reduction of the sugar with
hydriodic acid yields normal hexyl iodide, which proves that the carbon
chain is not branched. (4) Treatment with hydrogen cyanide and
saponification of the nitrile yields a heptanoic acid which, on reduction
with hydriodic acid, gives o-methyl hexanoic acid.
CN
CH3OH (CHOH)3–C–CH2OH + HCN->CH2OH (CHOH)3– b — CH3OH->
d on
COOH COOH
CH3OH (CHOH)3– &- CH3OH−, CH3(CH2)5– 6– CH3.
OH H
323414°–42 28
414 Circular of the National Bureau of Standards
This shows that hydrogen cyanide adds to the second carbon, and
therefore the carbonyl is on this carbon [12]. (5) The sugar yields
pentaacetates and other products which require the presence of five
hydroxyl groups. (6) Treatment with phenylhydrazine gives glu-
cosazone [13], which is further evidence that, except for carbons 1 and
2, dextrose and levulose are alike. In dextrose the reducing group
is located on the first carbon, and therefore the sugar is related to the
aldehydes, while in levulose the reducing group is located on the
second carbon and therefore levulose is related to the ketones. This
distinction is the basis for the further classification of the sugars as
aldoses and ketoses according to whether the reducing group lies on the
end carbon or on an intermediate carbon.
Even though the sugars give many of the reactions of aldehydes and
ketones, at least in neutral solutions they do not give certain specific
aldehydic and ketonic reactions, such as the red color with Schiff's
reagent, or the intense absorption bands in the ultraviolet region,
which are characteristic of free carbonyl groups [14]. The absence of
these distinctive aldehydic and ketonic properties is supposedly
explained by the interaction of the carbonyl group with the neighbor-
ing hydroxyl groups to form cyclic hemiacetals.
DEXTROSE
H /9 !on H
C H COH HCOH
hbon Héon Héon
Hobh Hoën O HOCH O
Hºoh Héon He—
Héon Hé– Hooh
bHoh Chon chon
Open-chain form. Pyranose form. Furanose form.
LEVULOSE
CH2OH CH2OH CH2OH
&—o —COH HOC–
Hobh Hobh Hoch
Hºoh O Héon Héon O
Hooh Héon Hé–
Choi —ch bHoh
#

Open-chain form. Pyranose form. Furanose form.
Although the cyclic hemiacetals can be considered as potential alde-
hydes, they differ fundamentally from the open-chain compounds and
exhibit many interesting properties. As early as 1846 Dubrunfaut
[15] noted that the optical rotation of freshly dissolved glucose changes
Polarimetry, Saccharimetry, and the Sugars 415
on standing, and he suggested that this change (mutarotation) was
due to a change in molecular composition of the sugar [16]. In sub-
Sequent years, this explanation received a striking confirmation in
the discovery of two forms of this sugar, which, in aqueous solution,
spontaneously revert to an equilibrium mixture of the two. Prior
to the discovery of the second form of glucose, Colley [17] had sug-
gested that one oxygen atom is combined with two carbon atoms to
form a cyclic structure. This idea was taken up by Tollens [18],
who recognized that various ring isomers are possible.
Lacking an experimental method for proving the size of the ring,
the early workers postulated a 1,4, or furanose ring, for the normal
Sugars and glycosides, but subsequent work has proved that the
normal methyl glycosides and crystalline sugars contain the 1,5, or
pyranose ring [19]. Several direct methods are available for determin-
ing the structures of the methyl glycosides, but the structures of the
free sugars rest on less satisfactory proof. Perhaps the best method
for ascertaining the structures of the aldoses is the bromine oxidation
method of Isbell and Hudson [20, 21], in which the pyranose and
furanose modifications are oxidized to give the delta or gammalactones,
respectively, without rupturing the lactol ring. Presumably the
reaction takes place in the following manner:
O -
1. HCOH `e-
2. Héon CY Héon
3. Hobh *** - Hoën O
4. Héon Ty Héon
5. HC– ô HC–
6. bHol Choi
Pyranose. 6-Lactone.
O
1. HCOH No
2. Héon CY Héon -
3. Hobn + Br2–3 Hobh O
4. Hè ºy Hè
5. Héon 6 Hºoh
6. Chon bHoh
Furanose. ºy-Lactone.



The validity of the method rests on the correct identification of the
delta and gamma lactones and on the hypothesis that the ring struc-
ture does not change either before or during the reaction. The
results obtained by this method and by other methods, such as the
comparison of the optical rotations of the sugars with the optical
rotations of glycosides of known structure, indicate that the crystalline
sugars so far investigated, with the exception of mannose-CaCl2. 4H2O
416 Circular of the National Bureau of Standards
and a few other sugar derivatives, contain the amylene oxide or
pyranose ring, while mannose-CaCl2.4H2O [22] and lactulose [23]
contain the butylene oxide or furanose ring. Sugars which contain
the amylene oxide ring are called pyranoses, and those which contain
the butylene oxide ring are called furanoses. The reducing carbon
in the cyclic sugar is asymmetric, and, therefore, each cyclic sugar
exists in two modifications. These modifications are designated
alpha and beta (see page 424). The alpha and beta modifications
of the various ring forms and the open-chain modification are mu-
tually interconvertible and exist in solution in dynamic equilibrium.
The optical rotations of these substances are not alike and conse-
quently, when a sugar is dissolved in water, the optical rotation
LEVULOSE
A -FRUCTOFURANOSE
DEXTROSE
o6 –GLUCOPYRANOSE
SUCROSE
FIGURE 101—Formulas for deactrose, levulose, and sucrose.
changes as equilibrium is established between the various modifica-
tions. This change in optical rotation is called mutarotalion, and the
reactions involved in establishing the equilibrium state are called the
mutarotation reactions. Crystalline dextrose is a glucopyranose,
levulose is a fructopyranose, and sucrose is a compound sugar having
a fructofuranose in combination with a glucopyranose.
The disaccharide union in sucrose is formed between the carbonyl
groups of dextrose and levulose, so that the carbonyl groups are com-
pletely blocked; for this reason, sucrose does not give the reactions
characteristic of a carbonyl or a potential carbonyl group. From an
analytical standpoint, the most important reaction of the carbonyl
group is the property of reducing alkaline copper reagents, such as
Fehling's solution. A sugar which has this characteristic is called a


Polarimetry, Saccharimetry, and the Sugars 417
reducing sugar. Sucrose, trehalose, melezitose, raffinose, and other
sugars in which the carbonyl groups are blocked, do not give the
characteristic reducing reactions and consequently they are called
nonreducing sugars in contrast to the reducing sugars. All mono-
Saccharides are reducing sugars. The reducing sugars also include
compound sugars which contain a free carbonyl group, as for example,
lactose, in which the carbonyl of a galactose radical is combined with
the hydroxyl of the fourth carbon of a glucose molecule. This leaves
the carbonyl of the glucose constituent free, and consequently the
sugar has the reducing properties characteristic of the carbonyl group.
Likewise, maltose, cellobiose, and gentiobiose are merely substituted
glucoses and contain free carbonyl groups. The disaccharide union
in these compounds is analogous to that found in certain products
known as glycosides. The term “glycosides” is generic, while the
terms “glucosides,” ” “galactosides,” “mannosides,” etc., refer to
glycosides of specific sugars. The glycosides are relatively stable
compounds and for this reason they are particularly useful in the
study of the structures of the sugars. The formulas of the individual
sugars and their stereoisomeric relations will be considered in more
detail after the subject of optical rotation in relation to molecular
structure has been discussed.
2. OPTICAL ACTIVITY IN ORGANIC COMPOUNDS
Optical rotation measurements are particularly useful for providing
information concerning the arrangement of the atoms in space and the
character of the atomic linkage. Some substances are optically active
in the crystalline state only, while others are optically active in the
crystalline, gaseous, liquid, or dissolved state. The optical activity
of the first group is due to the structure of the crystal, while the optical
activity of the second group is due to dissymmetry of the molecule.
From the time of Van't Hoff and Le Bel to the present, advances in
stereochemistry have shown that the only substances which exhibit
optical rotation in solution are those whose molecules are dissym-
metrical. Molecular structure depends primarily on the arrangement
in space of the groups which are covalently linked to an atom. The
chemical and physical properties of the elements show that the
valences of a group of four are directed toward the corners of a tetra-
hedron, a group of six toward the corners of an octahedron, and a
group of eight toward the corners of a cube [24]. Although optically
active substances are known to be derived from many elements, those
of carbon are the most important. Nearly all of the optically active
organic compounds contain one or more asymmetric carbon atoms. An
asymmetric carbon has four valences, which are satisfied by combining
with four different atoms or groups of atoms. As may be seen from
diagrams I and II in figure 102, a tetrahedral atom combined with four
different groups, a, b, c, d, can occur in two, and only two, distinct
stereoisomeric modifications.
Substances containing asymmetric carbons are characterized by
the fact that they are not identical with their mirror images. This
may be observed from diagrams I and II of figure 102. Two substances
whose molecules are related as object and mirror image are called
36 The early workers used the term “glucoside” in the generic Sense, but this use has been largely aban-
doned.
418 Circular of the National Bureau of Standards
optical antipodes, or enantiomorphs, and have like physical and
chemical properties, except for those properties which are character-
ized by directional components. Thus the optical rotations of
enantiomorphs are of like degree but of opposite direction; frequently,
but not always, their crystals are mirror images. Their reactions
with symmetrical molecules are alike, but their reactions with dis-
symmetrical molecules take place at different rates, and if the dis-
symmetry is not destroyed, they give different products. If equal
quantities of enantiomorphs are mixed, the optical rotation of one
neutralizes the optical rotation of the other, with the result that the
product appears to be optically inactive. Products containing equal
quantities of enantiomorphic substances are described as racemic.
When the enantiomorphs form a definite compound the product is
known as a racemic compound. The crystal structures, melting
points, solubilities, and energy contents of racemic compounds are
different from those of the constituents. In many respects racemic
compounds resemble double salts; in solution they dissociate, give
:
C
|
|
|
|
|
|
|
O
FIGURE 102.-Stereoisomeric modifications of an asymmetric carbon atom.
A, B, C, and D indicate the corners of the tetrahedron.
abnormal molecular weights, and exhibit the properties of the con-
stituent isomers. Some enantiomorphs do not yield true racemic
compounds, but give merely mixtures. In the absence of dissym-
metric substances, synthetic reactions leading to the production of
asymmetric carbons give racemic products because of the equal
probability of the formation of either isomer. However, should one
of the reacting substances be optically active, the introduction of
another asymmetric center results in products which are not related as
object and mirror image. For example, if d-glyceraldehyde is treated
with hydrogen cyanide, nitriles of erythronic and threonic acids are
produced in unequal quantities because d-glyceric aldehyde is dissym-
metric, and hence the probability of the formation of one isomer is
greater than the probability of the formation of the other. The two
nitriles are not identical and are not mirror images; they have char-
CN CN
hbon Hobh
Hºoh Hºoh
H2OH CH2OH
d–Erythronic nitrile. d-Threonic nitrile.




Polarimetry, Saccharimetry, and the Sugars 419
acteristic properties and are separate and distinct compounds. Com-
pounds of this character are called diastereoisomers. The number of
diastereoisomers which can be obtained for any structure depends on
the number of asymmetric carbons present in the molecule and on
whether the two ends of the molecule are alike. If the ends of the
molecule are different, two asymmetric carbons give rise to four iso-
mers and three asymmetric carbons give rise to eight isomers, but if
the ends of the molecule are alike, the number is less. For example,
tartaric acid contains two asymmetric carbons and exists in the three
modifications represented by the formulas:



COOH COOH COOH
He->0. Hoe- Hei-soº
S)H S)H OH
HO H He– OH H OH
DEXTRO-TARTARIC LEVO-TARTARIC MESO-TARTARIC
ACID ACID ACID
I II III
FIGURE 103.−Modifications of tartaric acid.
The two modifications represented by formulas I and II are enantio-
morphs. A mixture of these modifications crystallizes in a racemic
compound known as “racemic acid.” Racemic compounds are opti-
cally inactive by external compensation. The modification of tartaric
acid illustrated by formula III is fundamentally different from the
modifications illustrated by formulas I and II. Examination of the
structural model of formula III reveals that the upper asymmetric
carbon is the mirror image of the lower. On account of this relation-
ship, the upper asymmetric carbon rotates the plane of polarized light
by a certain amount to the right or left, while the lower asymmetric
carbon rotates the plane of polarization by an equal amount in the
opposite direction, with the result that the net rotation is zero. Sub-
stances which are optically inactive through internal compensation in
this manner are designated by the prefix meso, whereas racemic mix-
tures and compounds which are optically inactive by external com-
pensation are designated by the prefix dl.
The enantiomorphic modifications of an optically active substance
are distinguished by the single prefix d or l. The prefixes d and l were
originally used, and in many fields are still used, to indicate whether
the substance rotates the plane of polarization in the dextro (clock-
wise) or in the levo (counterclockwise) direction. Classification ac-
cording to the direction of the optical rotation frequently leads to
contradictory names for closely related substances. For example,
gluconic acid prepared from dextrose is levorotatory, its lactones and
alkali and alkaline earth salts are dextrorotatory, and its lead and
nickel salts are levorotatory. Furthermore, substances are known
which are dextrorotatory in one solvent, or at one temperature, and
levorotatory in a different solvent or at a different temperature.
420 Circular of the National Bureau of Standards
To avoid confusion, in the carbohydrate field enantiomorphic
modifications are classified according to configuration rather than ac-
cording to optical rotation. For example, dextrose and levulose are
designated d-glucose and d-fructose, respectively, notwithstanding
the dextrorotation of one and the levorotation of the other. Enantio-
morphs are classified by comparison with reference compounds. Emil
Fischer used d-glucose as his reference compound, but this led to
ambiguity because the reference compound contains several asym-
metric carbons. The classification in present use, originated by
Rosanoff, (25) avoids this complication by making dextrorotatory glycer-
aldehyde the reference substance. According to this system, the
sugars which have the same configuration for the terminal asymmetric
carbon as that of dextrorotatory glyceraldehyde are classified in the
d series, whereas those which have the reverse configuration are clas-
sified in the l series. The terminal asymmetric carbon is defined as
the asymmetric carbon farthest from the reducing group, or the one
adjacent to the CH2OH group if this group is present. This classifi-
cation is not satisfactory for those sugar derivatives in which both
ends of the molecule are alike. For example, the same dibasic acid is
obtained from d-glucose and from l-gulose. In such cases the classi-
fication is taken from the more important sugar. Thus the dibasic
acid derived from d-glucose is called d-saccharic acid.
It is necessary to distinguish between the use of d and l in the carbo-
hydrate field and the use of d and l in other fields of stereochemistry.
Levorotatory tartaric acid has the d-glyceraldehyde configuration;
hence, according to Rosanoff, it becomes d-tartaric acid in contrast
to its old and established name, l-tartaric acid. Confusion can be
avoided by using the symbol d (–), in which d signifies the configu-
ration and (–) the optical rotation. Most amino acids obtained from
proteins have the same configuration as l-glyceric acid and belong in
the l-series; but many exhibit dextro optical rotations and are fre-
quently called d acids. Some authors use capital D or L to signify
configuration and reserve the small letters for indicating optical ro-
tation. Unfortunately the small letters have been used indiscrimi-
nately for rotation and configuration and at present no uniform prac-
tice is established. Since the configurations for the hydroxy acids,
the amino acids, and the sugars and their derivatives have been es-
tablished, the time is ripe for the adoption of a uniform system.”
3. STEREOISOMERISM OF THE SUGARS
Our knowledge of the configuration of the carbohydrates has been
developed with the use of three dimensional models, based on the con-
cepts of Van't Hoff and Le Bel, and therefore the results of investiga-
tions in this field must be construed in relation to these models. The
models are represented in print by the projectional formulas originated
by Emil Fischer [26]. To obtain a projectional formula, the molecular
model is held in front of a sheet of paper, with the reducing group at
the top of the sheet and with the asymmetric carbon under considera-
tion placed so that its hydrogen and hydroxyl groups are directed
toward the observer, and so that the projections of the asymmetric
carbon and adjacent carbons fall in a vertical line on the paper. By
3. The d and l nomenclature is being considered at present by a Committee appointed by the Divisions of
giological Chemistry, Chemical Education, and Sugar Chemistry of the American C hemical Society.
Polarimetry, Saccharimetry, and the Sugars 421
projecting the carbon, hydrogen, and hydroxyl groups to the plane of
the paper, a formula is obtained in which the hydrogen and hydroxyl
groups lie on opposite sides of the vertical line connecting the carbon
atoms. The relation between the models and the projections is illus-
trated by the formulas for d- and l-glyceraldehydes.
If the molecule contains several asymmetric carbons they are pro-
jected on the paper in succession, keeping the carbon atoms in a ver-
tical line with the reducing group uppermost, and turning the asym-
metric carbon under consideration so that its hydrogen and hydroxyl
groups are directed toward the observer before making the projection.
The formula for the free aldehyde modification of d-glucose is repre-
sented below. If desired, the formula can be written horizontally
with the reducing group on the right. The carbon atoms of the
aldoses are numbered beginning with the reducing group, and of the
CHO CHO CHO CHO


º º º º
Ny. | Ny
CH2OH CH2OH CH2OH CH2OH
d-GLYCERALDEHYDE l-GLYCERALDEHYDE
FIG URE 104.—Relation between models and projectional formulas of d- and
l-glyceraldehyde.
ketoses beginning with the carbon on the end closer to the reducing
grOup.
8->
CHO I CH2OH 1
Hooh 2 =O 2
Hoch 3 H och 3
Hooh 4 Hooh 4
Hooh 5 Hooh 5
choi 6 chon 6
Aldehydo-d-glucose Keto-d-fructose
The investigations of Fischer [27] which established the configura-
tions of carbons 2, 3, 4, and 5 in the simple sugars were based on the
relationship of one sugar to another, and on the conversion of the
sugars to alcohols, acids, and Osazones. The latter products are open-
chain compounds and consequently their study provided valid proofs
for the structure of the open-chain modifications. When the open-
chain compound is converted into a cyclic structure, free rotation about
the carbon-carbon bonds is restricted and new structural problems
8.T1Sé.
Models for the ring modifications are obtained from the open-chain
models by turning the various atoms about the carbon-carbon axes
422 Circular of the National Bureau of Standards
in such manner that the hydroxyl on the fifth carbon for the pyranoses
(and on the fourth carbon for the furanoses) is brought into contact
and united with the carbonyl group. In the models representing the
pryanoses, the atoms comprising the ring do not lie in a single plane,
but form “Sachse” strainless ring structures. For representing the
cyclic structures in print, modified Fischer projectional formulas are
frequently employed, in which the lactol ring is drawn to the right
or to the left according to the position of the hydroxyl involved in ring
formation. These arbitrary formulas do not show the spatial relations
as well as Haworth's hexagonal formulas [19], but the latter are more
difficult to set in type. In the hexagonal formulas the hydrogen and
hydroxyl groups are considered to lie above and below the plane of
(i) nºon logº
(2) H COH H COH
| O | O
(3) Hoºh nogº
(4) ago. H COH
(5) º H¢
(6) CH,OH CH,OH
ck-o'-GLUCOSE /3–of– GLUCOSE
cº-d–GLUCOSE /3–0–GLUCOSE
FIGURE 105.-Fischer projectional and Haworth heavagonal formulas for d-glucose.
the ring, when the edge of the ring which is printed in heavy type, is
facing the observer.
The reducing carbon in the cyclic sugar is asymmetric and gives
rise to two modifications, alpha and beta. The alpha and beta modi-
fications depend upon whether the glycosidic hydroxyl lies on one
side or the other of the lactonyl ring. When either form is dissolved
in water, it undergoes spontaneously, at a measurable rate, intra-
molecular rearrangement whereby an equilibrium is established with
the other modification. Since the two modifications usually exist in
Solution in dynamic equilibrium, the total sugar in solution can be
separated in either form. By conductivity measurements in the pres-
ence of boric acid, Böeseken (28) proved that the glycosidic hydroxyl
of o-d-glucose lies in the same direction as the hydroxyl of the second
carbon, but on account of the tendency of the reducing sugars to

Polarimetry, Saccharimetry, and the Sugars 423
change from one form to another, for most sugars it is not possible
to determine the configuration of the reducing group by direct
methods. It is therefore necessary to assign structures for the alpha
and beta sugars by indirect methods, such as by comparison with
structurally related products.
If the hydrogen of the glycosidic hydroxyl is replaced by a methyl
group, a product known as a methyl glycoside is obtained. In
contrast to the free sugars, the glycosidic carbons in the glycosides do
not rearrange in neutral and alkaline solutions. For this reason the
configurations of the methyl glycosides can be determined by direct
chemical methods. As mentioned on page 415, the investigations of
Haworth and others have shown that the glycosides contain either
five- or six-membered lactonyl rings, and that they are analogous to
the alpha and beta furanose and pyranose sugars. Armstrong [29]
showed by enzymic splitting that methyl o-d-glucoside yields cº-d-
glucose, and that methyl 3-d-glucoside yields 3-d-glucose. This
proves that o- and 3-d-glucose are analogous to the alpha and beta
methyl d-glucosides. As noted by Simon [30], the optical rotations
for o- and 8-d-glucose and the methyl glucosides show the following
relationship:
Methyl ox-d-glucoside, +155. 5 o:-d-Glucose, + 106
Methyl 3-d-glucoside, – 31. 9 6-d-Glucose, + 22. 5
Mean---------------- +61. 8 . Mean - - - - - - - - - - - - - --64. 3
By extending this method of comparison the sugars can be correlated
with the corresponding methyl glycosides, the ring structures and
configurations of which have been determined experimentally.
A general method for ascertaining the configurations of the glyco-
sides was developed by Jackson and Hudson [31]. This method depends
on the reaction of the methyl glycosides with periodic acid, whereby
the sugar ring is ruptured to give optically active diglycolic aldehydes,
the configurations of which depend on the configurations of the first
and ring-forming carbons of the parent glycoside. Thus, when
methyl cº-d-glucopyranoside (I) is treated with periodic acid, D'-meth-
oxy-D-hydroxymethyl-diglycolic aldehyde * (II) is produced.

H OCH3 H OCH3
N | Z N | Z
C
Héon He—o
Hobh O O
Hooh HC=O
He– Hé
bion Choi
(I) (II)
Methyl ox-d- D'-Methoxy-D-
glucopyranoside. hydroxymethyl-diglycolic
aldehyde.
* In conformity with the publication of Jackson and Hudson, capital L and D are used in these names to
represent the configurations, rather than the small letters which are used elsewhere in this publication.
424 Circular of the National Bureau of Standards
The same product was obtained from the alpha methyl pyranosides of
glucose, mannose, galactose, and gulose. This proved that these
substances have like configurations for carbons 1 and 5, and since
the methoxyl of the glucoside lies to the right, as shown by the work
of Böeseken (28], the methoxyls in the methyl ox-d-galactosides, methyl
o-d-mannosides, and methyl a-d-gulosides must also lie to the right.
Application of the periodic acid oxidation to the beta pyranosides
of the same sugars gives L'-methoxy-D-hydroxymethyl-diglycolic
aldehyde, which proves that the glycosidic methoxyls lie to the left
in these 3-d-pyranosides. By essentially the same method the con-
figurations of other glycosides can be ascertained.
Fortunately there is a close relationship between the configurations
of the glycosides and their optical rotations. Insofar as our present
knowledge is concerned, those glycosides which give D'-methoxy
derivatives by oxidation with periodic acid are more dextrorotatory
than the corresponding glycosides which give L'-methoxy derivatives.
As brought out by the work of Hudson [32] in conjunction with the
periodic acid oxidations [31], the contribution of the glycosidic carbon
to the optical rotation is positive in those compounds in which the
hydroxyl or methoxyl groups lie to the right when the formulas are
written in the conventional manner. This relationship between con-
figuration and optical rotation is useful in naming the alpha and beta
modifications of the sugars and their derivatives.
4. NOMEN CLATURE OF THE ALPHA AND BETA SUGARS
One of the most fundamental principles of stereochemical nomen-
clature is that the names of enantiomorphs differ merely in the prefix
d or l. Thus the mirror image of o-d-glucose is called o-l-glucose.
Since the absolute configurations of the glycosidic carbons in the two
isomers are different, the absolute configuration cannot be used for the
alpha and beta nomenclature. In order that the names of enantio-
morphs be alike, in selecting the alpha-beta names it is necessary to
consider the configuration of the glycosidic carbon in relation to some
other group in the molecule, the configuration of which changes with
the d and l classification. For a reference group, Hudson selected
the terminal asymmetric carbon. This carbon is also used for the d
and l classification in the Rosanoff system.
According to Hudson's nomenclature [33] the more dextrorotatory
member of an alpha-beta pair in the d-series is designated as alpha,
and if the substance belongs in the l-series, the more dextrorotatory
member is called beta. Seemingly the optical rotations parallel the
configurations. Freudenberg [34] has suggested that the alpha-beta
names be based on configuration rather than on optical rotation.
According to Freudenberg's system, substances of like configuration
for the glycosidic and terminal asymmetric carbons are called alpha.
If the configurations parallel the optical rotations, Freudenberg's
and Hudson's classifications give the same names. In the normal
aldohexoses, the hydroxyl, united with the terminal asymmetric
carbon, forms the oxygen ring so that the configuration of this carbon
atom is a characteristic feature of the ring. In the heptoses and
higher sugars, the d and l classification depends on the configuration
of the sixth or higher carbon which lies in the side chain and does not
have anything to do with the configuration of the glycosidic carbon
Polarimetry, Saccharimetry, and the Sugars 425
For this reason, Hudson's and Freudenberg's alpha-beta names for the
higher sugars do not result in a correlation of substances of like con-
figuration for the groups comprising the pyranose ring.
Isbell [35, 36, 37] has pointed out the advantages of basing the
alpha-beta names on the configuration of the ring-forming carbon,
instead of the terminal carbon, and has suggested that substances
which have like configuration for the glycosidic and ring-forming carbons
be called alpha, while substances which have unlike configuration for
the glycosidic and ring-forming carbons be called beta.”
In this publication the foregoing rule is followed for all substances
in which the ring-forming carbon is asymmetric. In case the ring-
forming carbon is not asymmetric (as in the pentoses and ketohexoses),
substances having like configurations for the glycosidic and terminal
asymmetric carbons are called alpha, and those having unlike configura-
tions are called beta.
The alpha-beta classification, as used here, is based on configuration,
but since the optical rotations seem to parallel the configurations, the
alpha and beta names may be selected, at least provisionally, from
the optical rotations by the following rule:
The more dextrorotatory member of the alpha-beta pair is called
alpha if the ring-forming carbon has the d configuration, and beta if
the ring-forming carbon has the l configuration. In case the ring-
forming carbon is not asymmetric, the configuration of the terminal
asymmetric carbon is used in selecting the name.
Fischer projectional formulas and the corresponding names are
shown in figure 106 for the pentoses, hexoses, and heptoses. In the
alpha isomers the projection of the glycosidic hydroxyl or other func-
tional group falls at the point marked alpha; in the beta isomers the
projection of the functional group falls at the point marked beta.
3" A comparison of d-xylose, d-lyxose, l-arabinose, and l-ribose with d-glucose, (l-mannose, d-galactose,
and a-talose shows marked resemblance in the properties of each pentose and the configurationally related
d-hexose [38]. For this reason, Isbell suggested naming the alpha and beta pyranose modifications of d-xy-
lose, d-lyxose, l-arabinose, and l-ribose like the corresponding d-aldohexoses. In the ketose series, d-Sorbose,
d-tagatose, l-fructose, and l-psicose resemble the d-aldohexoses and might be classified likewise. The classi-
fication of the derivatives of l-arabinose and l-fructose with the closely related derivatives of d-galactose
permits generalizations in regard to the reactions and properties of the alpha and beta sugars, but it involves
changing the names for the derivatives of arabinose and fructose. Inasmuch as the alpha-beta nomencla-
ture for the derivatives of arabinose and fructose most widely used at present is based on the configuration
of the terminal asymmetric carbon, and since there appears to be a reluctance on the part of the workers
in this field to change the names, in this publication the names for substances in which the ring-forming
carbon is not asymmetric are based on the configuration of the terminal asymmetric carbon.
426
Circular of the National Bureau of Standards


• *- , º,
Héon Héon Hooh
Hobh O Hoën O Hoch o
Héon Héon Héon
H CH2OH HOCH
Choi
d-Xylose d-Glucose l-6-Galaheptose
8—C—o. • *- -->
Hoch Hoch Hoch
Hoëh O Hoch O Hoch O
Héon Héon Héon
he—l He— He—
h Choi Hobh
Chon
d–Lyxose d–Mannose l-o-Galaheptose
ſ
o—C—6 8-—C—o. --- 8—C—o.
Héon Héon Héon Héon
Hoch () Hoch O Hobh O Hoch ()
Hobh Hobh Hoch Hobh
HC– He He– He–
H chon Héon Hoºh
chon GHoh


l-Arabinose
-º-,
HOCH
|
HOCH
Hoch
HC–
H
O
l–Ribose
FIGURE 106,-Fischer projectional formulas and the corresponding names for the
pentoses, hearoses, and heptoses.
d–Galactose
d-Talose
º –
HočH Hoch
Hoch 0 Hobh 6
Hobh Hobh
He– He–
Heon Hoch
Choi bioh
d-8-Mannoheptose
l-8-Guloheptose
l-o'-Guloheptose
Polarimetry, Saccharimetry, and the Sugars 427


--- --
Héon Héon Héon
Héon O Héon O Hºoh O
Hºoh Hobh Hobh
He– He– He–
bH,on bHol Héon
- bH on
d-Allose d-Gulose d-or-Glucoheptose
6—C—o. 3–C—o. ---
Hobh Hobh Hobh
HCOH O Héon O Héon O
ſºon ſoºn noºn
HC– HC– HC–
bion &B,on Héon
bion
d–Altrose d-Idose d-6-Glucoheptose
noºcºon CH2OH.COH
Hobh HCOH
O Héon Hobh ()
Héon Héon
—ºn HC–
# h
Levulose


6-d-Fructose
ºcion
|
nºon
O nºon
HCOH
&H
H
8-d-Psicose
HC–
o:-d-Sorbose
colºr
HOCH
|
HOCH O
Héon
|
#
o:-d-Tagatose
FIGURE 106,-Continued
428 Circular of the National Bureau of Standards
5. CORRELATIONS BETWEEN OPTICAL ROTATION AND STRUCTURE
Study of the relationship between structure and optical rotation
began with Van't Hoff [39], who advanced the principle that the
optical rotation of the molecule is equal to the algebraic sum of rota-
tions due to the constituent atoms, the rotations of which change from
+A to — A when the atomic configuration is replaced by its mirror
image. Accordingly, Van’t Hoff represented the optical rotations of
the open-chain modifications of the four pentoses in the following
II].8.I] IlêI’.
No. 1 No. 2 No. 3 No. 4
+A -EA -EA – A
+ B + B – B –- B
+ C – C -- C -- C
“Since the sum of No. 2, No. 3, and No. 4 is equal to A+B+C, the
rotation of arabinose (probably the highest) should be equal to the
rotations of xylose, ribose, and the expected fourth type taken to-
gether.” This concept, which is designated as the principle of optical
superposition, has been applied to the sugars, sugar acetates, glyco-
sides, and many sugar derivatives. Van’t Hoff's fundamental prin-
ciple may be valid provided the asymmetric carbon is replaced by its
mirror image and no other changes follow. But each atom in the
molecule influences the neighboring atoms, and consequently a
stereoisomeric change results in a new distribution of atoms, electrons,
and electromagnetic fields so that the conditions necessary for the
valid application of the principle are not realized. The effect of
changes in the configuration of neighboring groups on the optical
rotation of an asymmetric carbon was noted by Rosanoff [40] and by
Freudenberg and Kuhn [41]. The configurations of the atoms ad-
jacent to a given asymmetric carbon appear to alter its optical rotation
markedly, while the configurations of the atoms separated from the
given asymmetric carbon appear to have less influence.
According to the principle of optical superposition, the optical
rotation of the sugar is equal to the algebraic sum of the partial
rotations at each of the asymmetric centers. For example, the molec-
ular rotation of o-d-lyxose is represented by Aon—R2–R3+R,
where Aoir, R2, R3, and R4 are the partial rotations at carbons 1, 2, 3,
and 4. The optical rotations and configurations of the pentoses,
hexoses, and heptoses are given in table 52.
Polarimetry, Saccharimetry, and the Sugars
429
TABLE 52.-Optical rotation and configuration for the pyranose sugars
Configuration
S 20 - Molecular
ugarS [o]; rotation
Cl C2 | C3 C4 C5 C6
PEN 'I'OSES
o-d-Lyxose---------------------------------. +5.6 + - - +|------|------ +84()
8-d-Lyxose---------------------------------.. –72. 6 — - - +------|------ —10, 900
a-d-Xylose----------------------------------. +93. 6 +} + — --|--|--|--|--|--|-- +14, 0.50
&-d:Arabinose "…---------------------------- — 19(). 6 l - + +------|------ –28, 61()
o-d-Arabinose. CaCl2.4H2O ----------------. –34. 7 + - + +------|------ — 11, 560
a-d-Ribose *.--------------------------------- | —20.3 + + +| +!------|------ –3, 0.50
M ETHYLPEN TOSES
o'-l-Rhamnose.H2O -------------------------. —8. 6 - + + - - I - - - - - - — 1, 570
8-l-Rhamnose-------------------------------. +38.4 + –H + - - * * +-6, 300
a-l-Fucose----------------------------------- — 15.2. 6 - - + + —|- - - - - - —25,050
o:-d-ISOrhamnose.--------------------- - - - - - - - +73. 3 + + - +- +|- - - - - - +12,030
HEXOSES
o-d-Glucose---------------------...------------ +112.2 + + - + +|------ +20, 210
S-d-Glucose---------------------------------. +18.7 - + - + +| - - - - - +3,370
o-d-Mannose-------------------------------. +29.3 + - - + +|- - - - - - +5, 280
A-d-Mannose--------------------------------- — 17. () - - - + +|- - - - - - —3,060
o-ſl-Galactose-------------------------------- +150.7 + —H - - +!------ +27, 150
8-d-Galactose---------------- - - - - - - - - - - - - - - - - +52.8 - + - - +|.----- +9, 510
o-d-Talose----------------------------------- +68.0 + - - - +]------ +12, 250
8-d-Talose----------------------------------- +13.2 - - - - --|------ +2,380
o:-d-Gulose. CaCl2.H2O.----------------------- +37. 1 + –H + - +|- - - - - - +11,470
8-d-Allose *----------------------------------- –0. 2 - –H + + +|- - - - - - –40
S-d-Altrose *.--------------------------------- +32.6 | - - + + +|- - - - - - +5,900
H F PTOSES
o:-d-of-Galaheptose.H2O ------------- - - - - - - - - - —25.2 - + + - - + –5, 750
8-d-6-Galaheptose---------------------------- — 19.2 + •- + - - + —4,040
o:-d-or-Guloheptose--------------- - - - - - - - - - - - - —45.7 - + + + - + –9, 610
o:-d-6-Guloheptose------------------- - - - - - - - - — 120. 5 - - + —H· - +| —25, 330
B-d-o'-Glucoheptose--------------------- - - - - - –28. 7 - + + - + + —6,030
6-d-6-Glucoheptose *------------------------- —0. 1 - - + - + + —20
o-d-o-Mannoheptose.H2O-------------------. +120.0 + + - - + + +27,380
6-d-o-Mannoheptose.H2O -------------------- +42. 3 - + - - + + +9,650
o:-d-6-Mannoheptose.H2O - - - - - - - - - - - - - - - - - - - +45, 7 + •º- - - + +| +10,430

1 Values obtained from enantiomorphic isomer.
2 Configuration questionable.
The value for twice the rotation (2R) of an asymmetric carbon, per-
haps better called the rotational difference, may be obtained by sub-
tracting the equations representing the optical rotations of the separate
sugars in such a manner as to eliminate all of the variables except one.
Some values calculated in this manner are given in table 53.
In
order to bring out relations between the various values for the ro-
tational differences and the configurations of the neighboring groups,
the configurations of the contiguous groups are indicated by the sym-
bols given in the column on the right. The first term in the symbol
represents the configuration of the carbon which lies above the one
under consideration, when the formula is written with the reducing
group uppermost, while the second term represents the configuration
of the carbon which lies below.
323414°–42——29
430
Circular of the National Bureau of Standards
The rotational difference corresponding to the first, or reducing
carbon, has been designated 2Aoa in accord with the terminology
originated by Hudson. The numerical values for 2Aom obtained from
the alpha and beta modifications of arabinose, glucose, and galactose,
and other sugars having like configurations for carbons 2 and 5, are
approximately 17,000, while the values from the rotations of mannose
and talose, and other sugars having unlike configurations for carbons 2
and 5, are considerably lower, approximately 10,000.
TABLE 53.−Differences in molecular rotation (principle of optical superposition)
. Configura-
Molecular rotations º * 1,
groups
l-Arabinose (+28,610) —l-arabinose CaCl2.4H2O (-|-11.560) 2A of +17, 050 ! (), --
o-d-Glucose (+20,210)—3-d-glucose (+3,370) - - - - - - - - - - - 24 OH | +16, 840 d, --
o:-d-Galactose (+27,150)—3-d-galactose (+9,510) - . . . . . . 2A OH | +17, 640 d, +
o:-d-o-Mannoheptose (+27,380)—3-d-o-mannoheptose (+9,650). 2A OH | +17, 730 d, --
o:-Lactose (+30,630)—3-lactose (+11,950) - - - - - - - - - - - . . . . . . . . . . 2AOH | +18, 680 d, --
a-d-Lyxose (+840)—3-d-lyxose (–10,900) - - - - - - - - - - - - - - - . . . . . . . . . . 2A OH | +11, 740 (), —
o:-d-Mannose (+5,280)—8-d-mannose (–3,060) - . . . . . . . 24 OH +8, 340 d, –
o:-d-Talose (+12,250)—3-d-talose (+2,380) - - - - - - - - - - - - - - - - - - - - - - - - - - - - , 24 Oh +9,870 d, -
o:-[4-Glucosido-mannose] (+5,300)—8-[4-glucosido-mannose] (–2,200) -- . . 24 OH | ––7, 500 d, -
a-d-Rhamnose (+1,570)—3-d-rhamnose (–6,300) -- - - - - - - - . . . . . . . . . . . . . . . 2.4 OH ––7, 870 d, -
o-d-Xylose (+14,050)—o-d-lyxose (+840) - - - - - - - - - - - - - - - - - - - - - - - - - - . . . . . 2R2 | +13, 210 o, –
o-d-Glucose (+20,210)—o-d-mannose (+5,280) -- - - - - - - - - - - - - - - - . . . . . . . . . 2R2 +14,930 o, -
o:-d-Galactose (+27,150)—o-d-talose (+12,250) -------- - - - - - - - - - - . . . . . . . . . . 2R2 | +14,900 o, -
o:-l-6-Guloheptose (+25,330)—a-l-a-guloheptose (+9,610) --- - - - - - - - - - - - - - 2R2 | +15, 720 o, –
o:-d-o-Mannoheptose (+27,380)—o-d-8-mannoheptose (+10,430) - - - - - - - - - 2R3 ––16, 950 o: , –
8-d-Allose (–40)—3-d-altrose (+5,900) - - - - - - - - -------- - - - - - - - - - - - - - - - - - - - - 2R2 —5, 940 6, -i-
8-d-o'-Glucoheptose (–6,030)—8-d-3-glucoheptose (–20) - - - . . . . . . . . . . . . . . 2R2 –6, 010 £8, --
B-d-Glucose (+3,370)—3-d-mannose (–3,060) - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2R3 || +6, 430 £3, –
8-d-Galactose (+9,510)—3-d-talose (+2,380) ------_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2R2 | +7, 130 £3, —
l-Arabinose (+11,560)—l-ribose (+3,050)--------------- - - - - - - - - - - - - - - - - - 2P2 | +8, 510 28, -
8-Cellobiose (+4,860) —8-4-glucosido-mannose (–2,200) - - - - - - - - - - - - - - - - - 2R2 | +-7, 060 8, -
8-d-Allose (–40)—3-d-Glucose (+3,370) - ----------------------------- . . . 2R3 | –3, 410 +, +
o:-d-Gulose (+11,470)—o-d-Galactose (+27,150) - - - - - - - - - - - - - - - - - - - - - - - - - 2R3 — 15, 680 +, −
8-d-o'-Glucoheptose (–6,030)—3-d-o-Mannoheptose (+9,650) - - - - - - - - - - - 2R3 — 15, 680 +, −
8-d-Altrose (+5,900)+8-d-mannose (–3,060) ------ - - - - - - - - - - - - - - - - - - - - - - - 2R3 +8,960 —, -i-
B-Celtrobiose (+4,900) —6-4-glucosido-mannose (–2,200) - - - - - - - - - - - - - . . 2R3 ––7, 100 —, -}.
o:-d-Xylose (+14,050) —8-l-arabinose (+28,610) - - - - - - - - - - - - - - - - - - - - - - - - - 2R4 — 14, 560 —, 0
6-d-Lyxose (–10,900)—l-ribose (+3,050) ---- - - - - - - - - - - - - - - - - - - - - - . . . - - - - 2R4 — 13, 950 —, 0
o:-d-Glucose (+20,210)—o-d-galactose (+27,150) - - - - - - - - - - - - - - - - - - - . . . . 2R4 —6, 940 —, --
B-d-Glucose (+3,370)—3-d-galactose (+9,510) --- - - - - - - - - - - - - - - - . . . . . . . . . . 2R4 –6, 140 —, --
o:-d-Mannose (+5,280)—o-d-talose (+12,250) -- - - - - - - - - - - - - - - - - - - - - - - - - - , 2R4 –6, 970 —, --
6-d-Mannose (–3,060)—3-d-talose (+2,380) ------ - - - - - - - - - - - - - - - - - - - - - - - - 2R4 || –5, 440 —, --
o'-l-o-Galaheptose (+5,750)—o-l-a-guloheptose (+9,610) - - - - - - - - - - - - - - - - - - 2R4 —3, 860 —, --
8-d-Mannose (–3,060)—o-l-gulose (–11,470) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2R5 +8, 410 Trams 1
5-d-Allose (−40)—o-l-talose (–12,250) - - ------------------------- - - - - - - - 2R5 +12, 210 TranS 1
cº-d-Galactose (+27,150)—3-l-altrose (–5,900) - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2R5 | +33,050 TranS 1
o:-l-o-Galaheptose (+5,750)—8-l-a-glucoheptose (+6,030) - - - - - - - - - - - - - - - - - 2R5 –280 Cis 1
o:-d-o-Mannoheptose (+27,380)—o-l-8-guloheptose (+25,330) - - - - - - - - - - - - - 2R6 +2, 050 +, 0
o:-d-6-Mannoheptose (+10,430)—o-l-o'-guloheptose (+9,610) - - - - - - - - - - - - - - 2R6 +820 +, 0
1 Hydroxyls on carbons 1 and 4 are cis or trams, as indicated.
2 Carbon 1 in cº-l-arabinose and in o-l-ribose (Hudson’s nomenclature) has the same configuration as carbon
1 in the 8-d-aldohexoses. See footnote 39.
The difference in the optical rotations of two sugars of diverse
configuration for carbon 2 gives 2R, a value which has been called
the “epimeric difference” [42].
The optical rotation of an asymmetric
carbon which lies between two asymmetric groups is influenced by
the configurations of both groups [43].
There are four arrangements
or combinations involving the configurations of the carbons which lie
on either side of carbon 2.
These are represented symbolically in the
following manner: (1) o, +; (2) o, -; (3) 6, +; (4) 3, −. Epimeric
Polarimetry, Saccharimetry, and the Sugars 431
pairs corresponding to the first group are not known products at
present but would be represented by oſ-d-gulose and o-d-idose, or by
o-d-allose and cº-d-altrose. In the hexose series the second group is
represented by o-d-glucose and o-d-mannose, and by oſ-d-galactose
and cº-d-talose. The epimeric differences obtained from these pairs,
+14,930 and + 14,900, are in excellent agreement. The third group
is represented by 3-d-allose and 8-d-altrose, and by 3-d-a-glucoheptose
and 3-d-3-glucoheptose. The epimeric differences for these pairs are
–5,940 and —6,010. Since these sugars have not been extensively
studied, it is quite possible that 3-d-altrose or 3-d-3-glucoheptose may
be improperly classified. The fourth group is represented in the
hexose series by 8-d-glucose and 8-d-mannose, and by 8-d-galactose
and 3-d-talose. The epimeric differences obtained from these pairs
are +6,430 and +7,130. The epimeric differences obtained for
various configurations bring out the need for considering the configura-
tion of adjacent groups in making comparisons, and emphasize the
complex character of the problem.
The rotational differences for carbon 3, obtained from sugars which
represent three possible combinations for the configurations of the
adjacent groups, give values of approximately — 16,000, −3,000, and
+8,000. The differences in these values show that the configurations
of the adjacent carbons influence rotation. Data are not available
for calculating the rotational differences for the fourth group. For
two of the configurations, the comparisons give results in approximate
agreement with one another.
The data available for calculating the rotational differences for
carbon 4 in the hexose series are limited to only one combination for
the configurations of the adjacent carbon 'atoms. Four calculations
from the optical rotations of eight sugars give values in approximate
agreement with each other, namely, -6,940, -6,140, -6,970, and
–5,440. These values are in accord with those obtained in the
heptose series for substances of like configuration, but they are not
strictly comparable with those obtained from the pentoses, because
the pentoses differ from the hexoses and heptoses in the substituent
group on adjacent carbon 5.
The determination of the optical rotation of carbon 5 is compli-
cated, because any change in its configuration affects the adjacent
ring oxygen, which in turn determines the alpha and beta positions
of the first carbon. Consequently, the rotational differences for
carbon 5 (2Rs) include any changes which may be induced by the
dissymmetry of the molecule as a whole. The data at hand are not
sufficient to evaluate this factor. The comparisons involving the
optical rotations of allose and altrose do not appear to be in accord.
The discrepancy may be caused by improper classification, erroneous
optical rotations, or unknown structural differences, such as differ-
ences in the conformation of the rings.
The rotational differences clearly show that optical rotation is not
uniformly an additive property and that dissimilarity in the configu-
rations of the contiguous atoms results in deviations from the Van’t
Hoff theory of optical superposition. The work of Tschugaeff, Kuhn,
Lowry, and others [24, p. 429] shows that each asymmetric carbon in
an optically active substance gives rise to one or more partial rotations,
which may be correlated with absorption bands of characteristic
frequency having their origin in particular electronic transitions
4.32 Circular of the National Bureau of Standards
taking place in the molecule. These transitions are not influenced
greatly by atoms or groups at some distance from the asymmetric
carbon but are influenced by the neighboring groups. The optical
rotation in the visible spectrum is chiefly governed by the absorption
bands nearest the wave length used for the rotation measurements.
Since the bands are not located at the same wave lengths for all
sugars, the partial rotation varies in irregular fashion with the wave
length. For this reason the difference in the rotations of two sugars
depends in part on the light used for making comparison, and it is
obvious that the optical rotations cannot be rigorously represented by
the simple algebraic equations suggested by Van't Hoff.
Nevertheless, the active part that the principle of optical super-
position has played in the development of carbohydrate chemistry is
sufficient justification for continuing its use. It has been amply
demonstrated that substances of similar structure and configuration
give approximately like rotational differences.
For correlating optical rotation and structure, Hudson [32] has
noted a number of approximations which are expressed in several
empirical rules. The so-called first rule of isorotation relates to the
optical rotation of the glycosidic carbon. If the formulas for alpha
and beta glucose are written as ring structures differing solely in the
configuration of carbon 1, and if the rotation due to the end asym-
metric carbon is A, and the rotation due to the rest of the molecule is
B, the molecular rotation of one isomer will be + A+ B, and the ro-
tation of the other isomer will be –A-H B. The sum of the rotations
is +2 B and their difference +2A. When the molecular rotations of
the alpha and beta modifications of glucose, galactose, and lactose are
compared on the one hand, and the molecular rotations of lyxose,
rhamnose, mannose, and 4-glucosidomannose are compared on the
other hand, it will be observed that the differences in the molecular
rotations for the alpha-beta pairs in each group are nearly constant.
The members of the first group have the configuration H–C–OH
for the carbon adjacent to the glycosidic group, while the members of
the second group have the configuration HO-C–H. Many similar
comparisons reveal that the rotational difference, 2A, is nearly con-
stant for substances which have like glycosidic groups, like ring struc-
tures, and like configurations on the adjacent carbon atoms. This
approximate equality is the basis of the first rule of isorotation which
states that the rotation of the glycosidic group is affected in only a minor
degree by changes in the structure of the remainder of the molecule pro-
vided the changes are not on the contiguous atoms.”
Hudson's second rule of isorotation relates to the optical rotation
of the rest of the molecule. The sum of the molecular rotations of
the alpha and beta sugars, +2B, varies from sugar to sugar, but if
the sums of the molecular rotations of the sugars are compared with
the sums of the molecular rotations of the methyl glycosides, it will
be observed that the values of 2B obtained for the sugars are in close
agreement with the values of 2B' obtained for the glycosides. This is
the basis for the second rule of isorotation which states that changes
in the structure of the glycosidic carbon affect in only a minor degree the
rotation of the remainder of the molecule. As may be observed from
data given in table 54, the values for 2B are in approximate agreement
49 Hudson's original rule does not exclude changes on the contiguous atoms.
Polarimetry, Saccharimetry, and the Sugars
433
for substances which do not have large differences in the glycosidic
group.
TABLE 54.—Sum of the molecular rotations (2B) for some alpha and beta derivatives
of d-glucose

$ Tº e [M] | [M] | sum * * * [M] | [M] | sum
Glycosidic group Alpha Beta A. 2B Glycosidic group Alpha Heta 2H3
form form forin form
-OH--------------- +20, 210 | +3, 370 +23, 580 || -O C3H5 (allyl) - - - - - +29, 010 —9, 320 | + 19, 690
- O CH3-- - - - - - - - - - - - +30, 860 | –6, 640 +24, 220 || - OCH2CH2 (OH) - - | +30, 380 —6, 850 | +23, 530
-OC2H5- - - - ------- +31, 360 | —6,950 | +24, 410 || -OCH2C6H5-- - - - - - - +35, 410 | – 15,020 | +20, 390
-OC3H7-- - - -------- +31, 290 —7, 760 | +23, 530 || -OC5H5- - - - - - - - - - - - +46, 330 — 18, 190 | +28, 140
The value of 2B obtained for the alpha and beta phenyl glucosides
(+28,140) differs considerably from the value (+24,220) obtained
for the alpha and beta methyl glucosides and related substances.
The introduction of an unsaturated chromophoric group appears to
induce a change in the optical rotation of the rest of the molecule.
The chromophoric group is particularly influential when adjacent to
the asymmetric center. Its influence is small when it is at some
distance from the asymmetric center, as for example, in the benzyl-
glucosides. As may be observed from the data given in table 55, the
sums for the molecular rotations of the alpha and beta sugars do not
differ widely from the sums for the molecular rotations of the corre-
sponding methyl glycosides.
TABLE 55.-Sums of the rotations of the alpha and beta sugars in comparison with
those of the o- and 3-methyl glycosides (second rule of isorotation)
Sum of the molecular Sum of the molecular
rotations of L rotations of
Substance o:-Methyl Substance o-Methyl
a-Sugar-H pyranoside-H o-Sugar-H pyranoside-H
B-Sugar 8-Methyl B-Sugar 8-Methyl
pyranoside pyranoside
d-Xylose - - - - - - - - - - - - - || 1 +11,050 +14, 510 || d-Glucose- - - - - - - - - - - - +23, 580 +24, 220
d-Lyxose----------- . . — 10, 060 —11, 280 || d-Mannose- - - - - - - - - - - y +1, 830
l-Arabinose----------- +40, 170 +43, 140 || d-Galactose-- - - - - - - - - - +36, 660 +38,050

! The value for the rotation of 3-d-xylose was taken from Hudson's indirect measurements by means of
Solubility experiments.
The accumulation of a large amount of experimental data has
brought out other approximations which are useful for correlating
optical rotation and structure. One of the most obvious is the
striking similarity in the optical rotations of substances which have
like configurations for the carbon atoms comprising the pyranose
ring. This generalization can be expressed in a rule which states
that changes in the side chains attached to the pyranose ring affect in only a
minor degree the rotation of the remainder of the molecule. The optical
rotations of a few sugar derivatives, which differ merely in the groups
attached to the pyranose ring, are given in table 56.
As might be anticipated from the close similarity in structure, the
molecular rotations of the configurationally related hexoses and
heptoses resemble one another more closely than they resemble the
rotations of the configurationally related pentoses and methyl pen-
434 Circular of the National Bureau of Standards
toses. A number of unexplained variations may be noted in table 56;
these call for further investigation to ascertain whether they arise
from errors or from unknown differences in structure.
TABLE 56.--Molecular rotation of substances of like configuration of the pyranose ring
Substituent group on carbon 5
H OH
Configuration of pyranose ring —H — CH3 | —CH2OH -&-choh –é-chon
| |
OH H
(Methyl
(Pentose) pentose) (Hexose) (Heptose) (Heptose)
SU G ARS
o:-d-Glucose (o-F—-H+) -- - - - - - - - ... +14,050 +12,030 | +20,210 |.........---------|------------------
6-d-Glucose (8+--|--|-)-- - - - - - - - - - - ----------|---------- +3, 370 +4,040 |- - - - - - - - - - - - - - - - - -
o:-d-Mannose (a –––H-H) - - - - - - - - - - +840 | +1, 570 --5, 280 +5, 750 ||------------------
B-d-Mannose (8––––––) - - - - - - - - - - - —10, 900 –6, 300 -3,060 ||------------------|------------------
cº-d-Galactose (o-H ––––) - - - - - - - - - - +28, 610 | +25,050 +27, 150 +25, 330 +27, 380
6-d-Galactose (8+––––) - - - - - - - - - - -H11, 560 |- - - - - - - - - - +9, 510 |- - - - - - - ----------- +9, 650
o:-d-Talose (o:----|-) - - - - - - - ------|----------|---------- +12, 250 +9, 610 +10, 430
B-d-Talose (8–––––) - - - - - - - - - - - - - +3,050 |- - - - - - - - - - +2, 380 ||------------------|-- - = • * = ~ *- m -- - * - *-* ~ * *
METHYL GLY COSIDES
o:-d-Glucose (ox-H ––––H) -- - - - - - - - - - - +25, 260 |_ _ _ _ _ _ _ _ _ _ +30, 860 +24, 200 |- - - - - - - - - - - - - - - - - -
B-d-Glucose (8–H–-H+) - - - - - - - - - - -| –10, 750 –9, 820 –6, 640 T C3 l'UO || - - - - - - - - - - - - - - - - - -
oc-d-Mannose (o:- —-H+) - . . . . . . . . +9, 750 +11, 140 +15, 380 +15, 700 |- - - - - - - - - - - - - - - - - -
3-d-MannoSe (8––––––) - - - - - - - - - --| –21,030 —17,000 || – 13, 550 | . . . . . . . . . . . . . . ---|-- - - - - - - - - - - - - - - - -
o:-d-Galactose (o-H----) - - - - - - - - - - +40, 300 | +35, 100 | +38, 180 | . . . . . . . . . . . . . ---|--|-- - - - - - - - - - - - - - -
3-d-Galactose (8+–––H) - - - - - -----| +2,840 —2,900 0 ------------------|------------------
ACETYLATED SUGARS
o:-d-Glucose (o-H--H+)-- - - - - - - - - - - +28, 400 |_ _ _ _ _ _ _ _ _ _ +39, 700 +25, 800 || -- - - - - - - - - - - - - - - - -
B-d-Glucose (8+–++) - - - - - - - - - - - - –7, 860 |_ _ _ _ _ _ _ _ _ +1, 480 – 14,000 || -- - - - - - - - - - - - - - - - -
o:-d-Mannose (o:- —-H+) - - - - - - - - - - -H8,000 ||---------- +21, 470 ||------------------|------------------
8-d-Mannose (8–––H-H) - - - - - - - - - - - -* * = <-2 = * * * - - –4, 620 –9,840 ||------------------|------------------
o:-d-Galactose (o-H––––) - - - - - - - - - - +46, 800 | +39,900 +41,650 |------------------ +55,860
8-d-Galactose (8+––––) - - - - - - - - - - +13, 500 |- - - - - - - - - - +9, 760 |------------------ +15, 770

Several relationships connecting the optical rotations and configura-
tions of the sugar acids and their derivatives have been noted. The
first of these is the Hudson lactone rule [44, 45], which states that
lactones, in which the oxygen ring lies to the right when the projec-
tional formulas are written in the conventional manner, are more
dextrorotatory than the parent acids, and if the oxygen ring lies on
the left, the lactone is the more levorotatory. The rule was originally
derived from the optical rotations of gamma lactones, but it appears
to apply equally well to the delta lactones. With the exception of
allonic, manno-nononic, and digitoxonic lactones, the sign of rotation
in water solution corresponds with the configuration of the ring-
forming carbon. That is, lactones in which the oxygen ring lies to
the right are usually dextrorotatory, while lactones in which the
Oxygen ring lies to the left are usually levorotatory. Levene [46, 47.]
and also Hudson [48] have pointed out that the phenylhydrazides and
amides of the aldonic acids are dextrorotatory when the hydroxyl on
the alpha carbon lies to the right. These relationships are very
useful for determining the structures of new acids formed by extending
the carbon chain, because frequently the phenylhydrazides and amides
Polarimetry, Saccharimetry, and the Sugars 435
are used for separating the products. Levene [46, 47] has shown that
the alkali salts of the aldonic acids are more dextrorotatory than the
free acids when the hydroxyl on the alpha carbon lies to the right, and
Isbell [49] has shown that the lead salts are more levorotatory than
the alkaline earth salts when the hydroxyl on the alpha carbon lies
to the right. These empirical rules make the classification of newly
prepared sugar acids a very simple matter.
TABLE 57.--Molecular rotation of the aldonic acids and related products

-Lac- - Phenyl- Configuration
Substance Acid "tº: Amide hydra-
* | C, C, C, C, C,
*Xylonie-------------------------------|---------- +13, 600 | +7, 350 |---------- + | – || --
d-ISOrhamnonic-------------------------|---------- +10, 850 ----------|---------- + | – || -- || +
d-Gluconic------------------------------ —1,350 | +12, 110 +6,090 +3,440 | + | – || + | +
!-8-Galaheptonic *-----------------------|----------|---------- +4, 500 | +2, 500 | + | – | + | + | –
d-Lyxonic------------------------------- +1, 100 | +12. 070 - - - - - - - - - -|-- - - - - - - - - — | – | +
d-Rhamnonic *--------------------------|---------- +-6, 360 —4,960 –4, 650 | – || – || + | +
d-Mannonic-----------------------------|---------- +9, 170 | –3, 380 | –2, 320 | – || – || + | +
l-o-Galaheptonic 1.---------------------- —570 | +10, 900 –3, 220 –2, 700 | – || – | + | + | –
l-Arabonic------------------------------ –1, 630 || –10, 600 +6, 190 +3, 560 || + | – || –
d-Fugonic -----------------------------|---------- — 12, 700 | +5, 570 |-- - - - - - - - - + | – || – | +
d-Galactonic -- - - - - - - - - - - - - - - - - - - - - - - - - - - –2, 670 | – 13, 790 | +6, 210 +2,980 | + | – || – | +
l-8-Guloheptonic 1 --------------- - - - - - - - - –2, 900 |- - - - - - - - - - - - - - - - - - - - +4, 870 | + | – || – | + || –
(l-o-Mannoheptonic -- - - - - - - - - - ----------|---------- — 15,450 | +6, 310 | +6, 600 | + | – | – | + | +
l-Ribonic - - - - - - - --- - - - - - - - - - - - - -- ~~ - - - - - - - - - - - +2, 920 –2, 660 –2, 710 || -- - - - - - - - - * I ºs- I -
d-Talonic - - - - - - - - - - - - - - - - - - - . . . . . . . . . . . . +3, 990 —6, 180 –2, 560 —7, 270 || – || – || – || +
d-8-Mannoheptonic - - - - - - - - - - - - - - - - - - - - +900 –7, 430 |---------- –8, 160 | – || – || – | + | +
l-o-Guloheptonic 1 - - - - - - - - - - - - - - - - - --| +2,850 | –5, 310 ||--|-- - - - - - - –9, 270 | – || – || – | + || –
(l-Gulonic------ - - - - - -- - - - - - - -- - - -- - - -- - - - - - - - - - - - - - - - - - - - —10, 170 +3, 140 |_ _ _ _ _ _ _ _ _ _ + | + | – || +
d-o'-Glucoheptonic ---------. . . . . . .-----| – 1,970 | –11, 660 +2, 390 +2,940 | + | + | – || + | +
(l-3-Glucoheptonic - - - - - - - - - - - - - - - - - - - - - - - +300 | – 17, 100 —6, 800 |- - - - - - - - - - — | + | – | + | +
d-Allonic acid---------------------------|---------- -1, 100*|- - - - - - - - - - +7,410 || -- | + | + | +
d–Altronic acid ------------------------ +1,600 ||----------|---------- –5, 300 | – | + | + | +
! Value derived from the enantiomorph by reversing the sign of the rotation.
The marked parallelism between the optical rotations and config-
urations which has been considered briefly is but one of many corre-
lations which exist between the properties and the configurations of
the sugars and their derivatives. In the next section, some of the
chemical properties will be considered in relation to structure and
configuration.
6. CORRELATIONS BETWEEN THE CONFIGURATIONS AND THE
CHEMICAL PROPERTIES OF THE SUGARS
The alpha and beta sugars have diverse configurations for their re-
ducing carbons and marked differences have been found in their
properties. An extensive investigation of the alpha and beta sugars
was initiated by Isbell, who sought to determine the effect of config-
uration on the relative reactivity of the alpha and beta sugars. Some
of the data obtained in this investigation are given in table 58, from
which it may be observed that the beta sugars are oxidized by bromine
water more rapidly than the corresponding alpha sugars.
436 Circular of the National Bureau of Standards
TABLE 58.-Rates of oxidation of alpha and beta sugars [35, 36, 37]
[In aqueous solutions at 0°C containing 0.05 mole of sugar, and approximately 0.08 mole of free bromine per
liter and buffered with barium carbonate and carbon dioxide)
Relative reaction rates
sugar Less re-
ka-d-glucose - active frac-
… * Cº - gº - 1. - 11. tion in
Sugar kg/ka equilib-
Alpha Beta form rumºr
form (cis) (trans) -
Percent
d-Glucose------------------------------------------------ 1. () 39 39 37
d-Mannose----------------- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1.6 24 15 69
d-Galactose----------------------------------------------- 1. 3 5() 38 3 |
d-Gulose------------------------------------------------- 2. 2 13 6 18
d-Talose-------------------------------------------------- 2.4 26 11 56
d-Xylose------------------------------------------------- 2.8 52 19 32
d-Lyxose------------------------------------------------- 4.9 14 3 80
!-Arabinose".--------------------------------------------- 3.0 52 18 32
!-Ribose'------------------------------------------------- 6. 1 45.5 8 89
d-8-Galaheptose. -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 0.8 53 66 37
d-or-Galaheptose.------- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2. 3 56 25 7
(l-o-Mannoheptose- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - . . . 1. 3 58 46 33
(l-3-Guloheptose------------------------------------------ l. 1 56 52 37
d-or-Glucoheptose----- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1.4 12 9 12
d-8-Glucoheptose - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 0. 9 1 1 12 22
!-Rhamnose---------------------------------------------- 2.8 24 9 69
Pactose-------------------------------------------------- 0. 9 30 33 38
Maltose-------------------------------------------------- ... 8 48 64 38
1 Isbell’s original nomenclature.
In many reactions the arrangement of the hydroxyls in relation to
the plane of the ring is an especially important factor in influencing the
rate and course of the reaction. Condensations in which two hy-
droxyls combine with another group take place when the hydroxyls lie
on the same side of the ring. Thus the behavior of the sugars and
their derivatives in their reactions with acetone, benzaldehyde, boric
acid, and many other substances is largely conditioned by the cis or
trans arrangement of the hydroxyl groups [50, 51, 28]. The facility
with which boric acid combines with cis-hydroxyls on adjacent atoms
was mentioned with respect to the structure of alpha and beta glucose
(p. 422). The property of increasing the electrical conductivity of
boric acid appears to be characteristic of all sugars which have two
hydroxyl groups on adjacent carbon atoms on the same side of the
ring. Normally, condensation with acetone involves cis-hydroxyl
groups on adjacent carbon atoms, making a cyclic link of five atoms
[52], while condensation with benzaldehyde usually involves alternate
cis-hydroxyls, making a cyclic link of six atoms [53].
In the presence of acid catalysts the free sugars react in the furanose
or the pyranose form, depending upon which form is the more favorable
for the condensation reaction. Thus glucose forms a 1,2-3,5-diacetone
derivative, even though the free sugar exists in the pyranose
modification. Correlations have been made also between the cis-trans
configurations and the tendency to form anhydrosugars and sugar
anhydrides. Thus o-d-glucose yields a glucosan by condensation
between the hydroxyls of carbons 1 and 2; 8-d-glucose, however,
yields a glucosan by condensation between the hydroxyls of carbons 1
and 6 [54]. Apparently the configuration of carbon 1 determines the
nature of the product formed. The importance of cis-trans configura-
Polarimetry, Saccharimetry, and the Sugars 437
tional relationships in the formation of anhydrosugars and ortho.
acetates was reviewed recently by Isbell [55], who suggested that many
carbohydrate reactions can be explained by Werner's concept [56] for
the Walden inversion. Intramolecular condensation reactions involv-
ing Walden inversion appear to take place only on the side of the
carbon opposite the departing group.
The influence of the cis-trans configuration of the sugars and their
derivatives in relation to their biological behavior has been recognized
for a long time. The Sorbose bacterium, for example, oxidizes sugar alco-
H
hols to ketoses when they contain the grouping, —C-C–—CH2OH,
OH OH
with the CH (OH) groups having a cis configuration in the projectional
formula [57]. The relationship between cis-trans configuration and
rates of enzyme action has also been studied [58].
Even though many generalizations can be reached by considering
only certain aspects of the molecule, each group influences to some
extent the properties of the others, and therefore it is essential to
consider also the configuration of the molecule as a whole. In the
pyranoses, the carbon and ring oxygen atoms are tied up in a ring and
cannot exhibit free rotation; consequently the pyranose ring forms a
fundamental structure about which the hydroxyls and hydrogens
are distributed according to the configurations of the constituent
carbon atoms. The arrangement of the groups on either side of the
ring makes up the thickness and general conformation of the molecule.
The different configurations for the 5 asymmetric carbon atoms of
the ring give rise to 32 isomeric pyranoses, which consist of 16 pairs
of enantiomorphs. These fundamental configurational types are
represented by the alpha and beta modifications of glucose, mannose,
galactose, talose, gulose, idose, allose, and altrose and are illustrated
by the formulas on p. 426. By substitution, all pyranose sugars
are derived from these fundamental types, or from their enantio-
morphs. The aldopentoses, methylpentoses, and heptoses differ
from the aldohexoses in that the CH2OH group of the latter is replaced
by hydrogen, the methyl group, or by the CHOH.CH2OH group,
respectively. The ketoses differ from the aldoses in that the H on the
first carbon of the aldose is replaced by a CH2OH group. If the sugars
are considered in this manner, sorbose, xylose, 3-galaheptose, maltose,
lactose, and cellobiose are merely substituted glucoses, or levulose,
perseulose, arabinose, or—mannoheptose, and 8-guloheptose are merely
substituted galactoses.
The tendency of a sugar or a sugar derivative to form five- or six-
membered lactol rings is dependent on the character of the substit-
uent groups, and on the configuration of the carbon atoms involved
in forming the furanose and pyranose rings. This subject will be
considered more fully in the next chapter.
7. REFERENCES
[1] E. O. von Lippmann, Geschichte des Zuckers, 2d ed., p. 683 (Julius Springer,
Berlin, 1929).
[2] Iowitz, Chem. Ann. von Crell 1, 218, 345 (1792).
[3] Chevreul, Ann. der Chym. 95, 319 (1815).
[4] Braconnot, Ann. Phys. Chim. 12, 172 (1819).
[5] F. J. Bates, Facts About Sugar 21, 250 (1926).
438 Circular of the National Bureau of Standards
[6] J. B. Dumas, Traité de Chimie 6, 273 (1843) (Paris).
[7] A. Baeyer, Ber. deut. chem. Ges. 3, 63 (1870).
[8] B. Tollens and F. Mayer, Ber. deut. chem. Ges. 21, 1566 (1888).
[9] H. Kiliani, Liebigs Ann. Chem. 205, 182 (1880).
10] J. Meunier, Compt. rend. 111, 49 (1890).
[11] H. Kiliani, Ber. deut. chem. Ges. 19, 767 (1886).
[12] H. Kiliani, Ber. deut. chem. Ges. 19, 221 (1886).
[13] E. Fischer, Ber. deut. chem. Ges. 17, 579 (1884).
14] L. Marchlewski and W. Urbanczyk, Biochem. Z. 262, 248 (1933).
15] Dubrunfaut, Compt. rend. 23, 38 (1846).
16] T. M. Lowry and G. F. Smith, Rapports sur les hydrates de carbone, p. 79,
ſ 10th Conference of the International Union of Chemistry (Liege, 1930).
[
17] Colley, Compt. rend. 70, 403 (1870).
18] B. Tollens, Ber. deut. chem. Ges. 16, 921 (1883).
19| W. N. Haworth The Constitution of Sugars (Edward Arnold & Co., London,
1929).
H. S. Isbell and C. S. Hudson, BS J. Research 8, 327 (1932) RP418.
H. S. Isbell, BS J. Research 8, 615 (1932) RP441.
H. S. Isbell, J. Am. Chem. Soc. 55, 2166 (1933).
H. S. Isbell and W. W. Pigman, J. Research NBS 20, 773 (1938) RP1104.
T. M. ºwn, Optical Rotatory Power (Longmans, Green and Co., London,
1935).
5] M. A. Rosanoff, J. Am. Chem. Soc. 28, 114 (1906).
6] E. Fischer, Ber. deut. chem. Ges. 27, 3211 (1894).
7] E. Fischer, Uuntersuchungen über Kohlenydrate und Fermente (Berlin,
1909 and 1922).
28] J. B. Böeseken, The Configuration of the Saccharides (translated by S.
Coffey, page 58, A. W. Sijthoff, Leyden, (1923).
[29] E. F. Armstrong, J. Chem. Soc. 83, 1305 (1903).
[30] L. J. Simon, Compt. rend. 132, 487 (1901).
|31] E. L. Jackson and C. S. Hudson, J. Am. Chem. Soc. 59, 994 (1937).
[32] C. S. Hudson, BS Sci. Pap. 21, 241 (1926) S533.
[33] C. S. Hudson, J. Am. Chem. Soc. 31, 66 (1909).
[34] K. Freudenberg, Stereochemie, page 692 (Franz Deuticke, Leipzig and
Wien, 1932).
[35]. H. S. Isbell, J. Research NBS 18, 505 (1937) RP990.
[36] H. S. Isbell and W. W. Pigman, J. Research NBS 18, 141 (1937) RP969.
[37] H. S. Isbell, J. Chem. Education 12, 96 (1935).
[38] W. W. Pigman and H. S. Isbell, J. Research NBS 19, 189 (1937) RP1021.
[39] J. H. Van’t Hoff, The Arrangement of Atoms in Space (translated by
Eiloart. Longmans, Green and Co., London, (1898).
[40] M. A. Rosanoff, J. Am. Chem. Soc. 28, 525 (1906); 29, 536 (1907).
[41] K. Freudenberg and W. Ruhn, Ber. deut. chem. Ges. 64, 703 (1931).
[42] C. S. Hudson, J. Am. Chem. Soc. 48, 1434 (1926).
[43] H. S. Isbell and H. L. Frush, J. Research NBS 24, 125 (1940) RP1274.
[44] C. S. Hudson, J. Am. Chem. Soc. 32, 338 (1910).
[45] E. Anderson, J. Am. Chem. Soc. 34, 51 (1912).
[46] P. A. Levene, J. Biol. Chem. 23, 145 (1915).
[47] P. A. Levene and G. M. Meyer, J. Biol. Chem. 31, 623 (1917).
[48] C. S. Hudson, J. Am. Chem. Soc. 39, 462 (1917).
H. S. Isbell, J. Research NBS 14, 305 (1935) RP770.
| F. Micheel and H. Micheel, Ber. deut. chem. Ges. 63, 386 (1930).
[51] W. N. Haworth and E. L. Hirst, Ann. Rev. Biochem. 5, 82 (1936).
[52]. R. G. Ault, W. N. Haworth, and E. L. Hirst, J. Chem. Soc. 1935, 1012.
] L. Zervas, Ber. deut. chem. Ges. 64, 2289 (1931).
] A. Pictet and P. Castan, Helv. Chim. Acta 3, 645 (1920). N. Cramer and
E. N. Cox, Helv. Chim. Acta 5, 884 (1922). A. Pictet and J. Sarasin,
Helv. Chim. Acta 1, 87 (1918). P. Karrer and A. P. Smirnoff, Helv.
Chim. Acta 5, 124 (1922).
[55] H. S. Isbell, Ann. Rev. Biochem. 9, 65 (1940).
[56] A. Werner, Ber. deut. chem. Ges. 44, 873 (1911).
[57] M. G. Bertrand, Ann. chim. phys. 3, 181 (1904).
[58] B. Helferich, S. Winkler, R. Gootz, O. Peters, and E. Günther, Z. physiol.
Chem. 208, 91 (1932).
Polarimetry, Saccharimetry, and the Sugars 439
XXIX. MUTAROTATION AND SUGARS IN SOLUTION
1. CHARACTERISTICS OF THE EQUILIBRIUM STATE
Dubrunfaut [1] discovered that when glucose is dissolved in water,
the optical rotatory power of the solution decreases on standing until
finally it reaches a constant value. Subsequently, Pasteur [2],
Erdmann [3], and others [4] found that the optical rotations of freshly
prepared solutions of the reducing sugars in general change on stand-
ing, a phenomenon which came to be known as mutarotation.
In 1846, when Dubrunfaut discovered mutarotation, he advanced
the hypothesis that the change in optical rotation is caused by a
change in molecular structure. After many years this hypothesis
was confirmed by Tanret's preparation [5] of two forms of glucose
and lactose, one having a higher rotation than the stable solution
and the other having a lower rotation. Fischer's preparation of
two methyl glucosides and Armstrong's discovery [6] that on enzymic
hydrolysis the more dextrorotatory glucoside yields a sugar solution
with a rotatory power greater than the equilibrium value and that
the less dextrorotatory glucoside yields a sugar solution with a ro-
tatory power less than the equilibrium value furnished a clue as to
the character of the change involved in the mutarotation reaction.
Subsequent work has shown that the mutarotation reactions consist
in the reversible interconversion of the various modifications of the
Sugars and that many mutarotation reactions are caused almost
entirely by the interconversion of the alpha and beta pyranose modi-
fications. Since the several modifications in the sugar solution have
different physical properties, the mutarotation reaction may be fol-
lowed by the changes in solubility, volume, refractivity, and energy,
in addition to the optical rotations.
As mentioned on page 414, the equilibrium involves the structures
found in the open-chain sugar, the alpha and beta pyranose modifica-
tions, and the alpha and beta furanose modifications. The relative
proportions of these constituents vary greatly from sugar to sugar
and with the experimental conditions. The separation of numerous
Open-chain derivatives is evidence for the presence of the open-chain
modification, but the lack of strong characteristic aldehydo reactions
indicates that the open-chain modification is not present in large
quantity. In weakly alkaline solution some sugars show a faint
absorption band in the region characteristic of the carbonyl group
[7]. This absorption band is further evidence that the open-chain
modification is present only in small quantity. The ease with which
the alpha and beta pyranose modifications can be crystallized shows
that they are the predominating constituents of the sugar solution.
For alpha and beta furanoses there are no characteristic qualitative
tests such as the absorption band of the open-chain modification.
The preparation of the methyl furanosides and other furanose deriva-
tives and the crystallization of a calcium chloride compound of a
manno-furanose [8, 9] imply that the furanoses are present. This
inference is further substantiated by the complex mutarotation reac-
tions, and by the similarity of the mutarotation of levulose to the
mutarotation of the furanose form of levulose liberated from sucrose
by invertase [10].
The position of the equilibrium between the various modifications
in sugar solutions appears to depend upon the configuration of the
440 Circular of the National Bureau of Standards
sugar and upon the substituent groups. Aldoses which have the
glucose, mannose, and gulose structures establish equilibrium states
consisting almost exclusively of the alpha and beta pyranose modifica-
tions [11]. Aldoses which have the galactose, talose, and idose struc-
tures establish equilibrium states containing small but substantial
quantities of the furanose modifications and larger quantities of the
alpha and beta pyranose modifications [12, 13, 14, 15]. Sugars
which have the fructose structure establish equilibrium states con-
sisting for the most part of a single pyranose modification with a
substantial proportion of a furanose modification [10], and sugars
which have the allose, altrose, Sorbose, and tagatose structures es-
tablish equilibrium states consisting largely of a single pyranose
modification [16, 17, 18, 19]. Replacing the hydrogen of the alde-
hydo group by a CH2OH group to give a ketose results in a large
alteration in the equilibrium proportions of the various ring and open-
chain modifications of the resulting sugar. Isbell and Pigman [10]
have shown that an equilibrium solution of levulose does not contain
an appreciable quantity of the beta pyranose modification, even
though the equilibrium solution of the structurally related aldose
(d-arabinose) contains 73 percent of the beta pyranose modification.
Furthermore, the proportions for the modifications of sorbose and
of tagatose also differ widely from the proportions found for the con-
figurationally related sugars, glucose and mannose. The aldoses
and ketoses differ on the carbon atom involved in forming the lactol
ring; that is, the structural difference is on the carbon involved in the
ring-forming reaction. When viewed in this light, the differences in
the equilibrium states for the aldoses and ketoses are understandable
and comparable to the differences in the equilibrium states for the
Sugars and sugar acids.
The aldonic acids can be considered as derived from the aldoses by
replacement of the hydrogen on carbon 1 by a hydroxyl. In aqueous
º they establish equilibrium with the delta and gamma
actOnes.
o o on o
SS SS SS
6–1 & 6–
|
Hooh –3, H COH —3. HCOH

i |
HCOH 9 — HQOH – HGoH 9
| |
HC–
| nºon HCOH
CH2OH CH3OH HC–
Gamma lactone Acid IDGlta lactone
On account of differences in the chemical properties of the acids and
lactones, the composition of the equilibrium solutions for the acids can
be determined more readily than the composition of the sugar solu-
tions. In marked contrast to the sugars, the equilibrium mixtures for
the aldonic acids contain larger quantities of the five-membered ring
modifications (gamma lactones) and smaller quantities of the six-
membered ring modifications (delta lactones). The marked difference
in the equilibrium states of the aldoses, ketoses, and aldonic acids
Polarimetry, Saccharimetry, and the Sugars 441
shows that the groups attached to the carbonyl carbon greatly influence
the equilibrium proportions of the open-chain and ring modifications.
If the configurationally related acids are compared, it may be observed
that acids which have like configurations for the o, 3, y, and 6 carbons
give similar equilibrium states. For example, equilibrium solutions
of acids having the mannose configuration contain large proportions of
the gamma lactones, while equilibrium solutions of acids having the
glucose configuration contain larger proportions of the delta lactones
and the free acids.
Attempts to determine the composition of sugar solutions have
resulted in a number of methods for estimating the proportions of the
constituents and the rates of change from one form to another, but
none of these methods is entirely satisfactory. The methods may be
classified roughly as (a) those which attempt to remove and study the
separate constituents of the solution, and (b) those which depend on
physical measurements of the solution as a whole. The removal of a
constituent from the system by crystallization or chemical reaction
causes an equilibrium disturbance which constitutes a limitation for
all methods involving the separation of one of the constituents of the
system. Measurements of physical properties, such as optical rota-
tion, do not disturb the equilibrium, but usually the interpretation of
the results is complicated, because the physical properties depend on
all of the components in the solution and not on a single substance.
When the components are available in the crystalline state, the infor-
mation derived from freshly prepared solutions may be used to com-
plement the results obtained with the equilibrium solutions. Informa-
tion thus obtained is satisfactory for the more stable modifications in
simple mixtures, but there is no really satisfactory method for deter-
mining the proportions of the labile components in complex mixtures.
2. CRYSTALLIZATION AND SOLUTION
If an equilibrium solution of glucose or another reducing sugar is
concentrated and seeded with the alpha pyranose modification of the
sugar in the absence of other seed, the pure alpha modification crystal-
lizes from solution. The equilibrium disturbance caused by the
separation of alpha crystals from solution causes the formation of
more of the alpha isomer until finally all the sugar is converted to the
alpha pyranose modification. Likewise, if the solution is seeded with
the beta pyranose modification in the absence of alpha seed, the beta
sugar crystallizes from solution until finally all of the sugar is converted
to the beta pyranose modification. The reverse of this process, that is,
the process of dissolving the sugar, has proved very useful in obtaining
information concerning the equilibrium state [20, 21, 22]. If a finely
powdered modification of a sugar is shaken continuously at constant
temperature with a solvent in which it is only slightly soluble (so that
the laws of dilute solutions apply), the solvent becomes Saturated very
quickly with the crystalline modification, but the sugar continues to
dissolve at a slow rate. This apparent increase in solubility is caused
by the conversion of the sugar into other modifications. If it is
assumed that the solubility of a given modification is the same through-
out the solubility experiment, the initial solubility of the crystals
discloses the quantity of that modification present in the solution at
any time, and the “maximum rate of solution” gives the rate of
442 Circular of the National Bureau of Standards
formation of other modifications. Measurements with lactose have
shown that the total sugar which will dissolve is substantially equal to
the sum of the initial solubilities of the alpha and of the beta crystals.
This indicates that the equilibrium solution of this sugar consists
almost entirely of the two modifications. If equilibrium is established
between only two modifications, alpha and beta, then, as Hudson has
shown [23], the initial solubility of the alpha form (So), the final
solubility (S.), and the solubility (S.) at any time (t) measured from
the beginning of the experiment may be represented by the equation,
1ſt ln (S. — So)/(S,-Sa)=ke,
where k2 is the velocity constant for the rate at which unit concen-
tration of the beta form changes back to the alpha form. Likewise,
the solubility of the beta form is given by an analogous equation,
1ſt lm (S. – S.)/(S - Sº) =k),
in which the solubilities represent those obtained by measurements
with beta crystals, and the constant (k) is the velocity constant for
the conversion of the alpha form to the beta form. The sum of k,
and k obtained from solubility measurements with o- and 8-lactose
is in accord with the sum (ki + kg) obtained from optical-rotation
measurements. The agreement of the results from the solubility
and the optical rotation measurements shows that for lactose the
equilibrium is satisfactorily represented by the two-component system,
ki
cº The equilibrium constant, ki/kg, can be calculated (1) from
Č2
ki and k, as determined by the “maximum rate of solution”, (2) from
the initial and final solubilities by means of the relation, ki/kg =
(S.–So)/S6, and (3) from the optical rotations by means of the rela-
tion, ki/kg = (ro-re)/(r. —rs). With lactose, glucose, and many
other sugars the three methods give like values. This is evidence
that for these sugars the equilibrium state is represented within
experimental error by a system containing two isomers in dynamic
equilibrium. Certain sugars, however, give experimental results
which are not in accord with a reversible system involving only two
components.
3. MUTAROTATION OF FRESHLY DISSOLVED SUGARS
(a) MUTAROTATION EQUATIONS
In 1899 Lowry suggested that the mutarotation of nitrocamphor
is caused by a reversible reaction [22]. Hudson showed that the two
forms of lactose give equal velocity constants for their mutarotations
and, in addition, that the maximum rate of solution of the crystals
is in accord with the hypothesis that the change in rotation is not
caused by different reactions but by opposite parts of one balanced
reaction. By applying the mass action law to the reversible reaction
ki
represented as cº,
2
Polarimetry, Saccharimetry, and the Sugars 443
Hudson developed the following equation:
70 – 7"co
7" — r.
k-k- logº-ºº: (135)
in which t equals the time of dissolution, ro the optical rotation at
zero time, r the rotation at the time t, and rº, the final or equilibrium
rotation. The mutarotation coefficient, k + k2, is usually expressed
in common logarithms, but if the values of ki and k2 are to be applied
in kinetic problems, they must be converted to a natural logarithmic
base by multiplying by 2.3026. The mutarotations of glucose, lac-
tose, mannose, and similar sugars follow the course of a first-order
reaction and give satisfactory values for the mutarotation coefficients.
Mutarotations which give uniform values for ki–H k, may be repre-
sented by an equation of the type
[a] = A 10-m' C, (136)
in which [o] equals the specific rotation at the time t, A equals the
difference between the initial and final rotation, C equals the final or
equilibrium rotation, and mi equals the mutarotation coefficient,
k1 + k2. If the mutarotation coefficient is expressed in natural log-
arithms, the equation is written as an exponential function of e, as
follows:
[o]=Ae-*-|-C, (137)
in which k= (ki + k2) × 2.3026. If the logarithms of (r–r.) at various
times are plotted against time, a linear curve is obtained provided
eq 135 is applicable.
If eq 135 is not applicable, the mutarotation coefficient changes
as the reaction proceeds, and the logarithms of (r—r.) do not fall
|6
e-,
º
&
4 8 12 16 20 24 28 32 36 40 44 48 52 56 6O
TIME – MINUTES
FIGURE 107.-‘‘Simple” and “complex” mutarotation curves.

444 Circular of the National Bureau of Standards
on a linear curve (see the curve for o-d-talose in fig. 107). The
sugars which exhibit complex mutarotations undoubtedly establish
equilibrium states which contain substantial quantities of more than
two modifications of the sugar. The mutarotation reactions fall in
two classes: (1) Those which are relatively slow and appear to con-
sist in the interconversion of the alpha and beta pyranose modifica-
tions, and (2) those which are relatively rapid and appear to consist
in the interconversion of the pyranose and furanose modifications.
The prevalence of systems containing more than two sugar modifi-
cations in equilibrium is shown by the work of Riiber and Minsaas [12]
Riiber, [24], Sørensen (25), Smith and Lowry [13], Worley and Andrews
[26], Dale [8], and Isbell [10, 11, 15, 18, 27, 28]. Riiber and Minsaas
showed that the changes in “solution volume” and refractivity, which
occur during the mutarotation of galactose, can be explained by
assuming that equilibrium is established among three modifications.
From a study of the optical rotations, Smith and Lowry also came to
the conclusion that the equilibrium involves three modifications, and
they developed the following equation to express the optical rotation,
o, at any time, t:
o-Ae-mit--Be-m; +C. (138)
This equation, which is essentially the same as the one developed
by Riiber and Minsaas, represents two consecutive reactions, as
azey-22. As applied to the sugar series, the equation is more or less
empirical, but it appears to fit the data for the complex mutarotations
as completely as eq 136 fits the simple alpha-beta interconversion.
Equation 138 can be expressed to the base 10, rather than to the base
e, in which case the exponents m1 and m2 are in common logarithms
rather than in natural logarithms. In this form the equation reads
o-A10-mit- B10-mit-i-C, (139)
in which A is the change in optical rotation due to the slow or alpha-
beta pyranose interconversion, B is the difference between the initial
rotation and that obtained by extrapolation of the slow mutarotation
to zero time, and C is the equilibrium rotation. The exponents mi
and m2 are functions of the velocity constants for the separate reac-
tions which take place during the mutarotation and represent the
rates at which the slow and fast changes in optical rotation occur. In
order to develop equations of this type from the experimental data
(see p. 156 of reference 11), the mutarotation is divided into two
periods, a short period beginning at zero time, during which a rapid
change occurs, and a long period beginning at the practical completion
of the rapid change. By applying the formula
_ ] log ri – r.
mi-i-I, Og p
to the data representing the long period (that is, the last part of the
mutarotation), values of mi are obtained. It will be observed that
m1 is the Ordinary mutarotation coefficient measured for the latter
part of the mutarotation and that a mutarotation which follows the
simple unimolecular course gives rise to only one exponential term.
The constant, for the initial rapid change m, is calculated from the
following equation:
(140)
2 7 co
Polarimetry, Saccharimetry, and the Sugars
445
1 d
me=E-i log d.’ (141)
in which di and dº represent the differences between the observed
rotations and those obtained by extrapolation of the long period back
to the corresponding times. The extrapolation is accomplished
mathematically by substitution in eq. 140
TABLE 59.—Mutarotation of a-d-galactose [11]
5.0 g per 100 ml at 20.0° C read in a 4-dim tube.
°S = 37.51 × 10--00803 t-H 3.25 × 10−.079 t + 46.34.
[o]}=*SX 1.7307.
Sacchar-
Time imeter (k1+ kg) × 103 In 1X 103 I)eviation m2)(103
reading
1 2 3 4 5 6
Minutes oS oS
. 9 +84.85 || ---------------|-- - - - - - - - - - - 2.30 ------------
3. () +83. 67 12. 3 || ----------- 1.84 88.1
4. 4 +82. 44 11. 3 |------------ 1. 52 72. 0
6. 6 +80. 54 11.0 |------------ 1. 00 77.0
8, 6 +-79.03 10.6 ------------ 0.69 78. ()
10. 2 +77.95 10.3 |------------ . 55 74. 9
}2. () +76.73 10. 2 |------------ . 34 83.9
14.8 +75. 09 9.8 |-- - - - - ------ . 22 79. 0
29. 7 68.00 9.0 -----------|------------|------------
45. () +62.66 8. 7 8.04 ||------------|------------
59. 8 +58. 75 8. 5 8.04 || ----------- -
80. () +54.92 8.4 8.00 ------------|------------
100. 7 +52. 18 8. 3 8.02 ------------|------------
| 19. 5 +50. 47 8. 2 8.01 ------------|------------
149. 9 +48.66 8. 2 8.07 ------------|------------
CO +46. 34 || ---------------|------------|------------|-----------
Average---|-----------|---------------- 8.03 |- - - - - - - - ---- 79. 0
The following example is based on the data for the mutarotation of
o-d-galactose, table 59, and is given to clarify this description.
Column 2 gives the observed rotations at the indicated times. The
calculation of mi is begun at 29.7 minutes, as calculations started
at earlier times give a drift in the constant. The values of mi given
in column 4 are obtained by application of eq 140, using r1= +68.00,
t = 29.7, and for ro, readings taken at later times. The slow reaction
is carried back to times earlier than 29.7 minutes by substituting the
average value of mi, (8.03X107°), in eq 140, and solving for r at each
of the times, t, earlier than 29.7 minutes (including zero time), using
r2 = +68.00, r. = +46.34, and t2=29.7. (The equilibrium rotation,
re, subtracted from the calculated value at zero time, gives A in eq 139.)
These values, subtracted from the observed rotations at the corre-
sponding time, give the differences shown in column 5 of the table.
The constant, m2, for the rapid change is then obtained by substituting
the differences in eq 141, using di = 2.30, t = 1.9, and for d, the values
recorded at the later times, t. By placing the average value of m2
(79.0×107°) in eq 141, and using d2=2.30 and tº −1.9, the value of
di at zero time, ti, may be obtained by solving the equation. The
value so obtained (3.25) is that to be used for B in eq 139. The
equilibrium rotation (46.34) is C; A (37.51) is the difference between
323414°—42——30
446 Circular of the National Bureau of Standards
the equilibrium rotation (46.34) and the calculated value of r, at zero
time (83.85), which has already been obtained by application of eq 140.
The substitution of these values in eq 139 gives the equation.”
°S=37.51 × 10−00808?–1–3.25 × 10-079–146.34. (142)
If it is desired to use the natural logarithmic base, eq 142 is changed
only by replacement of the base 10 by the base e, and by multiplying
each of the exponents by 2.3026. The equation, which expresses the
optical rotations as observed, is converted to a specific rotation by
multiplying by the ratio of the equilibrium specific rotation to the
observed equilibrium rotation. For example, in the mutarotation
represented by eq 142, the equilibrium specific rotation of galactose
was found from a separate experiment to be 80.2. The ratio of the
equilibrium specific rotation to the observed equilibrium rotation is
80.2/46.34, or 1.7307. Multiplying eq 142 by this factor gives the
mutarotation in terms of specific rotation.
A summary of some mutarotation measurements, which have been
conducted at the National Bureau of Standards during recent years, is
given in table 149, p. 762 of this publication. The measurements
reported therein were conducted as described in the following
paragraph.
(b) MEASUREMENT OF MUTAROTATION
Mutarotation measurements are conveniently made in the following
manner: The carefully purified sugar is powdered in an agate mortar
and passed through a fine sieve. The weighed sample (about 2 g)
is placed in a dry 100-ml glass-stoppered flask and about 50 ml of
distilled water (preferably of known pH, or buffered with 0.001 N.
potassium acid phthalate,)* at the correct temperature is added with
agitation. The water can be added conveniently from a fast-draining
pipette. Time, beginning with the addition of the water, is measured
with a stop watch. After the sugar is dissolved, the solution is trans-
ferred to a water-jacketed polariscope tube and maintained at the
desired temperature while optical rotation measurements are made.
The work is preferably conducted in a room held at the temperature
selected for the measurement; in any case, the water which circulates in
the jacket of the polariscope tube should be held at constant tempera-
ture by a suitable thermostat. The optical rotations are measured
directly after the solution of the sugar, and at such times thereafter
as required to disclose the changes that occur. It is convenient for
one person to make polariscope readings while another notes the times
and records the results. It is usually advisable to make the observa-
tions in groups of 5 or 10 readings which (unless mutarotation is taking
place rapidly) can be averaged for use in calculating the velocity con-
stants. The method used for calculating the equations to represent
the mutarotations and the mutarotation coefficients is given on
page 444,
The equilibrium specific rotation of the sugar is determined with a
separate sample of the sugar. It is necessary to use the same concen-
tration and temperature as those employed in the mutarotation
measurements.
* The optical rotation was read in sugar degrees. tº
4? 0.2041 g of potassium acid phthalate (NBS Standard Sample 84) dissolved in 1 liter of water,
Polarimetry, Saccharimetry, and the Sugars 447
(c) VELOCITY AND EQUILIBRIUM CONSTANTS FOR THE MUTAROTATION
REACTIONS
As already mentioned, the mutarotations of certain sugars consist
of two or more reactions which involve three or more substances in
dynamic equilibrium. The calculation of the separate velocity and
equilibrium constants for all the mutarotation reactions is scarcely
feasible at present because the number and character of the reactions
are not known. By postulating that the mutarotation involves only
two isomers, the separate velocity and equilibrium constants may be
calculated from ki–H kg (eq 135, p. 443), and the equilibrium con-
stant ki/kg, which is obtained from the optical rotations by the
equation
ki 7'o - ?"co
kº re-re (143)
Some values of ki and k, thus calculated are given in table 60.
TABLE 60.—Equilibrium constants calculated from optical-rotation measurements,
assuming that only two isomers are present in dynamic equilibrium
Mutaro-
tation Optical rotation Velocity constants 2
coefficient 1
Tem-
Sugar pera-
ture ſalp:
ki-H k2 ſold, [o]p, equilib- k1 k2 ki
o:-isomer | 8-isomer Titl|OOl k2
mixture 1
o C
20 0.0580 +5.6 –72. 6 —13. 8 || 0.0144 0.0436 0.330
d-Lyxose- - - - - - - - - - - - - - * { 0.2 | . 00842 +4.7 —70.8 — 13.4 | . 00202 . 0.0640 . 31.5
d-Glucose { 20 . 0.0629 +112.2 +18.7 +52.7 . 00400 . 00229 1. 750
- - - - - - - - - - - - - - - 0.2 . 000740 +111.5 +18.4 +52. 1 . 000472 . 000268 1, 763
d-Mannose { 20 . 0176 +29.3 —17. 0 —H·14. 2 . OO57 . 0119 0.484
- - - - - - - - - - - - - 0.3 . 00215 +28.8 —16. 7 +14. 6 . 00067 . 00148 .454
d-Lactose { 20 . 00469 +89.5 —H34.9 +55.4 . OO293 . 001.76 1. 663
- - - - - - - - - - - - - - - 0.2 . 000534 +90.9 +36. +56.4 . 000337 . 00019.7 1. 716

Average of values obtained from the alpha and beta isomers.
* Expressed in minutes and in logarithms to the base 10.
(d) EFFECT OF TEMPERATURE ON THE MUTAROTATION RATE
In accordance with the general behavior of chemical reactions, the
velocity for the mutarotation of a sugar is accelerated by a rise in
temperature. Between 25° and 35° C the rates increase from one
and one-half to three times, depending upon the sugar and upon the
character of the mutarotation reaction. The normal alpha-beta
pyranose interconversions have higher temperature coefficients than
the rapid mutarotation reactions (pyranose-furanose interconversions).
The effect of temperature on the rate of mutarotation is represented
most satisfactorily by means of the integrated Arrhenius equation,
k' QY 1 1
in which k’ and k” are velocity constants at the absolute tempera-
tures, Ti and T3; R is the gas content; and Q is the heat of activation.
In 1904 Hudson determined the effect of temperature on the velocity
448 Circular of the National Bureau of Standards
constants for the conversion of alpha to beta lactose and for the
conversion of beta to alpha lactose. Subsequently, Lowry [4, p. 102)
calculated, from Hudson's data, the following heats of activation:
O rºo
1.8 ... & Mean
- - Cal. Cal. Cal.
Heat of activation o—ºg calculated from ki---------------. 17, 730 | 18, 800 18, 300
Heat of activation 6—so calculated from kº ... ----------| 17, 100 | 18, 000 17, 500
Application of the integrated Arrhenius equation to the data in table
60 gives the following heats of activation:
ki
o:-Glucose —- 6-Glucose= 17,170 cal.
&
6-Glucose → o:-Glucose = 17,240 cal.
ki
o:-Lactose — 8-Lactose = 17,380 cal.
8-Lactose → o:-Lactose = 17,600 cal.
Čſ
o–Mannose — 8-Mannose = 17,300 cal.
k2
8-Mannose — o-Mannose= 16,840 cal.
l
o:-Lyxose — 8-Lyxose = 15,780 cal.
6–Lyxose → o:-Lyxose = 15,420 cal.
It may be observed that the heats of activation for the alpha-
pyranose isomers do not differ widely from the heats of activation for
the beta-pyranose isomers. If the heat of activation for the alpha
isomer equals that for the beta isomer, the value of Q obtained by
application of the Arrhenius equation to the mutarotation coefficient
(ki + kg) likewise is equal to the same heat of activation. If the heats
of activation of the alpha and beta isomers as calculated from ki and
k2 are not equal, the value of Q obtained from the mutarotation
coefficient (ki + kg) is not a true heat of activation. Nevertheless, it is
useful for comparing mutarotation measurements at different temper-
atures and for differentiating between mutarotation reactions of
different types. Isbell and Pigman [11] found that the values of Q
obtained from the mutarotation coefficients for the alpha-beta pyra-
nose interconversions are larger than the values obtained from the
mutarotation coefficients for the pyranose-furanose interconversions.
(e) EFFECT OF TEMPERATURE ON THE EQUILIBRIUM STATE
The effect of temperature on the equilibrium state can be ascer-
tained most readily by observing the mutarotation which follows a
change in temperature. When a sugar solution is cooled rapidly, a
nearly instantaneous change in optical rotation takes place. This is
followed by a mutarotation, the direction and rate of which furnish
Polarimetry, Saccharimetry, and the Sugars 449
quantitative information concerning the shift in equilibrium. Muta-
rotations of this character are called thermal mutarotations. In 1909
Hudson [29] observed that when a solution of glucose, galactose,
xylose, lactose, or maltose is cooled, a very small mutarotation takes
place, from which he concluded that, at the higher temperature, the
equilibrium solution contains more of the alpha sugar. The investi-
gations of Isbell have shown that the equilibrium state between the
alpha and beta pyranose modifications changes only slightly with
changes in temperature, whereas the equilibrium state between the
pyranose and furanose modifications changes considerably with
temperature. Usually in the mutarotations of the freshly dissolved
sugars, the changes due to the alpha-beta pyranose interconversions
are large in comparison with those due to pyranose-furanose inter-
conversions. In the thermal mutarotations, however, the changes
due to the alpha-beta pyranose interconversions are small in com-
parison with those due to the pyranose-furanose interconversions.
Consequently, the thermal mutarotations are useful for estimating the
velocity constants for the pyranose-furanose interconversions. Some
typical thermal mutarotations are given in table 61.
The relatively large temperature effects for the pyranose-furanose
equilibrium indicate that the heats of reaction are considerable;
correspondingly small changes in the alpha-beta pyranose equilibrium
indicate that the heats of reaction for the alpha-beta interconversions
are small. -
The heat of reaction (AH) can be calculated from the equilibrium
constants, but unfortunately in most cases these are not known.
Application of the Wan’t Hoff equation
to the equilibrium constants given in table 60 gives, for the heat of
reaction in calories, values of +374, −59, --517, and —252 for the
mutarotations of lyxose, glucose, mannose, and lactose, respectively.
By direct measurement Brown and Pickering [30] found a thermal
change of -835 calories per gram molecule for the mutarotation of
levulose and smaller values for the mutarotations of dextrose, lactose,
and maltose. Riiber and Minsaas [12] found that the rapid mutarota-
tion reaction of o-d-galactose is accompanied by the absorption of
heat, whereas the slow alpha-beta interconversion is accompanied by
the liberation of heat.
450
Circular of the National Bureau of Standards
TABLE 61.--Thermal mutarotation for sugars eachibiting complex mutarotation.
Thermal mutarotation of a 10-percent aqueous solu-
tion of d-galactose after cooling it from 25° to 0.3°C.
°S= 1.10 × 10-00107 t—3.49).< 10–0132 t +97.87
Time 1 Saccharime. n1X10 3 Deviation Tm2X10 3
ter reading
Minutes oS oS
5. 74 +96.02 |_ _ _ _ _ _ _ _ _ _ _ _ –2.93 || -----------
6.95 +96. 13 |_ _ _ _ _ _ _ _ _ _ _ _ —2.82 13. 8
10. 00 +96.49 | . . . . . . . . . . . . –2.45 18.2
15, 13 +96. 74 |_ _ _ _ _ _ _ _ _ _ _ _ –2. 19 13.5
20.09 +-97.04 || . . . . . . . . . . — 1.88 13. 4
26, 15 +97. 32 |_ _ _ _ _ _ _ _ _ _ _ _ —1.58 13. 1
30, 20 +97. 46 | . . . . . . . . . . . —1. 43 12. 7
40. 27 +-97. 76 | . . . . . . . . . . . . —1. 10 12, 3
50, 11 +-98.02 || . . . . . . –0.82 12. 5
60. 96 --98.23 -- - - - - - - - - - - - —. 59 12. 6
75. 23 +98. 41 || . . . . . . . . —. 37 12.9
89.97 +98. 48 || . . . . . . . . . —. 27 12. 3
126. 54 +98.53 - - - - - - - —. 14 10. 9
139, 88 +-98.60 . . . . . . . . . . . . —. 05 13. 2
160. 18 +98.61 |------------|------------------------
244. 19 +98.45 1. 26 ||--------------|------------
306. 1 +98.39 1.05 - - - - - - - - - - - - - - - - - - - - - - - - --
365. 2 +98. 30 1.15 --------------|------------
502. 1 +98. 24 0.88 |- - - - - - - - - - - - - - - - - - - - - - - - - -
738. 7 +98.06 1.02 --------------|------------
CO +97.87 ------------|----...-------|------------
A Verage---|-------------- 1.07 ||-------------- 13.2
Thermal mutarotation of an 8-percent aqueous
solution of l-arabinose after cooling it from
25.2° to 0.2° C. 9S = 1.52X 10-.00364 t—4.56×
10-.0271 t-i- 101.71
4. 57 +99. 74 || - - - - - - - - - - - –3. 43 || -- - - - - - - - - - -
5.94 +100.01 . . . . . . . . . . -- —3. 15 27. 0
8. 29 +100.38 . . . . . . . . . . . . –2. 75 25.8
10. 64 +100. 75 |_ _ _ _ _ _ _ _ _ _ _ _ –2.35 27. 1
15. 16 +101.30 | . . . . . . . . . . . . — 1. 75 27. 6
20. 21 +101. 71 | . . . . . . . . . . . . — 1. 28 27.4
25. 58 +102.01 |_ _ _ _ _ _ _ _ _ _ _ _ —.93 27. 0
30.06 +102.20 |_ _ _ _ _ _ _ _ _ _ _ _ —. 69 27.3
40. 10 +102.45 |_ _ _ _ _ _ _ _ _ _ _ _ —. 35 27. 9
51. 15 +102.55 |_ _ _ _ _ _ _ _ _ _ _ _ —. 12 (31. 3)
75. 14 +102.52 ------------|--------------|------------
90. 19 +102.41 4, 21 |--------------|------------
121.06 +102.26 3.66 || - - - - - - - - - ----|------------
154. 66 +102.11 3.85 --------------|------------
184. 1 +102.06 3.34 ||--------------|------------
214. 6 +101.98 3.42 |--------------|--|--|-- . . . . . .
277. 9 +101.87 3.47 || -------------|--|-- . . . . . . .
330. 6 +101.81 3.56 |--------------|-----------.
389.9 +101.77 3.59 |- - - - - - - - - - - - - - - - - - - - - - - - -
QQ +101.71 ------------|--------------|------------
Average---|-------------- 3.64 ||-------------- 27. I
1 Measured from the beginning of the cooling process.
Polarimetry, Saccharimetry, and the Sugars 451
(f) EFFECT OF ACIDS AND BASES ON THE MUTAROTATION RATES
The acceleration of the mutarotation rates of the sugars by acids
and bases has been the subject of many investigations. The early
workers attributed the catalytic effect of acids and bases to the hydro-
gen and hydroxyl ions, but subsequent work has revealed that catalysis
is not the exclusive property of the hydrogen and hydroxyl ions.
Experiments by Lowry and coworkers, [4, p. 111, by Brönsted and
Guggenheim [31], and others have disclosed the catalytic activity of
molecules of undissociated acids, of anions of weak acids, and of cations
of weak bases. In general, amphoteric solvents are complete catalysts
for the mutarotation, while hydrocarbons, chloroform, and carbon
tetrachloride do not promote mutarotation.
It may be observed from the curve given in figure 108 that the
velocity for the mutarotation of glucose in aqueous solutions does not
change appreciably in the range from pH 2.5 to 6.5. However, in more

.C.V. || A GALACTOSE (Fast º:
2|E GALACTOSE (sLow REACTibN)
#|..}}}}#
O16 4| O G E
O.12
O
O
\
004,
2 º
ood # ER5–
| 2 3 4. 5 6 7 8
- AH
FIGURE 108—-Variation of the mutarotation constants with pH [10].
strongly alkaline or acid solutions, the velocity rises rapidly with
increasing concentrations of the hydrogen and hydroxyl ions. If
carefully purified distilled water, free from carbon dioxide, is em-
ployed in mutarotation measurements, the velocity constants are
substantially higher than those obtained in slightly acid solutions.
Fortunately the region of minimum velocity falls in the pH range of
distilled water containing carbon dioxide, such as the water ordinarily
used for mutarotation measurements. Minute quantities of bases
suffice to cause large alterations in the rate, and therefore it is difficult
to obtain satisfactory velocity constants except in the presence of an
acid-base buffer. Mutarotation measurements made with unbuffered
solutions in nickel, brass, or copper tubes give substantially higher
velocity constants than those made in glass tubes [32]. The higher
constants appear to be due to an alteration in the acidity caused by
the metallic oxide from the tubes which dissolves in the sugar solution.
452 Circular of the National Bureau of Standards
Precautions are necessary in making mutarotation measurements to
avoid accidental catalysis. In order that results from different sources
be placed on a comparable basis, the use of 0.001 N. potassium acid
phthalate is recommended as a solvent for mutarotation measurements.
According to Hudson, the catalytic activity of water in the mutarota-
tion of glucose may be represented by the equation
k=0. 0096-1-0. 258 [H+] +9750 [OH-].
The equation shows that the alterations caused by the hydrogen and
hydroxyl ions are proportional to their concentration but that there
is a residual catalytic activity which is now considered to be due to
undissociated Water molecules.
In the mutarotation of glucose at pH 4.7, the contribution of the
hydroxyl ion to the catalysis is about 40,000 times that of the hydrogen
ion, and the residual catalytic effect of the water is nearly 500 times
that of the combined catalytic effect of the hydrogen and hydroxyl ions.
Lowry and Faulkner [33] showed that pure pyridine and pure cresol
do not promote mutarotation; however, a mixture of 1 part of pyridine
with 2 parts of cresol does accelerate the rate for the mutarotation
of tetramethyl glucose to 20 times that obtained in water solution.
Lowry explained this seemingly anomalous behavior by assuming that
for the mutarotation to take place the solvent must possess acid and
basic properties simultaneously. Pyridine and cresol, or pyridine and
water, or water alone, can act both as an acid and as a base, but pyri-
dine alone can act only as a base and cresol alone can act only as an
acid. In this connection the acid and basic functions are used in the
Brönsted sense, that is, the ability to give or to accept protons. The
molecules of an undissociated acid can give, and the anions of a weak
acid can accept, a proton, as follows:
CH3COOH−, gives H++ CH3COO-
CH3COO− accepts H+–CH3COOH
The ammonium cation can give a proton, and ammonia, can accept a
proton as follows:
NH4+ gives H+, leaving NH3
NH3 accepts H+, giving NH4+
Undissociated water accepts a proton and forms the H3O+ ion or gives
a proton and forms the hydroxyl ion. The anions of highly ionized
strong acids and metallic cations do not give or accept protons and
hence do not exhibit catalytic activity. In harmony with this concept,
calcium chloride, sodium sulfate, and other metallic salts of strong
acids do not accelerate the mutarotation reaction, while salts of weak
acids, like sodium acetate, have marked catalytic action. Isbell and
Pigman [10] have shown that the mutarotation of levulose and the
rapid mutarotation of galactose are extremely sensitive to the catalytic
action of acids and bases. The extreme sensitivity of the pyranose-
furanose interconversions to acid and basic catalysts furnishes a con-
venient means for distinguishing them from the alpha-beta pyranose
interconversions.
Polarimetry, Saccharimetry, and the Sugars 453
(g) EFFECT OF THE SOLVENT AND OTHER SUBSTANCES ON THE EQUILIBRIUM
STATE
The optical rotations of the reducing sugars in different solvents
vary widely. The variation results, in part from the fact that a
given constituent will have different optical rotations in different
solvents, and in part from the displacement of the equilibrium between
the various sugar modifications. The effect of a change in the solvent
on the equilibrium state can be ascertained most readily by observing
the mutarotation which follows a change of solvent. For example
when a concentrated aqueous solution of galactose is diluted with
several volumes of alcohol, a nearly instantaneous change in optical
rotation takes place. This is due to the difference in the optical
rotations of the constituents because of the change in solvent. The
initial change in rotation due to the new solvent is followed by a com-
plex mutarotation reaction which apparently consists of the rapid
+35
+30
+25
;
.
5O5O
;
O
-IO
-º-; ;-z-z-z-z-z-z-z-z-z-z- ©º
Time - N1inutes
FIGURE 109.-Mutarotation of d-gwlose CaCl2.H2O.
and slow mutarotation reactions previously discussed. This complex
mutarotation shows that in some manner the equilibrium between
the various constituents is altered by a change in solvent. The effect
of solvents on the equilibrium state has not been investigated very
thoroughly. Apparently in some cases the solvent combines with the
sugar, and may facilitate the separation of different modifications of
the sugar. For example, d-glucose crystallizes from pyridine solutions
in the form of a pyridine compound which contains the beta pyranose
modification; while from water solutions at ordinary temperatures
d-glucose crystallizes in the form of a hydrate which contains the
alphapyranose modification. The existence of numerous solvated
sugars and sugar derivatives shows that the solvent is not merely an
inert medium in which the sugar is dissolved. Isbell [34] has shown
that the position of the equilibrium between the various modifications

454 Circular of the National Bureau of Standards
of d-gulose in solution can be altered by the addition of calcium
chloride, or by changing the concentration of d-gulose calcium chloride.
The mutarotation which follows a change in the concentration of
d-gulose calcium chloride indicates that in some manner the sugar
equilibrium is displaced by the change in concentration. The addi-
tion of a Salt to the system complicates the equilibrium conditions
by forming molecular compounds with the various isomeric forms of
the sugar, some of which compounds have been isolated. In dilute
Solution the compounds are largely dissociated into the sugar and
calcium chloride. As shown by the curves given in figure 109, dilu-
tion of a concentrated solution of d-gulose CaCl2.H2O with water
results in the formation of the more levorotatory modification of
d-gulose, while dilution with alcohol results in the formation of the
more dextrorotatory modification. Obviously the equilibrium ex-
isting in an alcoholic solution of d-gulose CaCl2.H.2O is different from
the equilibrium existing in an aqueous solution. Similarly, the equilib-
rium of d-a-glucoheptose is shifted by calcium chloride in a manner
comparable to the shift observed for d-gulose [35].
Another interesting example of the influence of calcium chloride on
the equilibrium state is the formation of a calcium chloride compound
of the furanose modification of d-mannose [8, 9]. A pure aqueous
solution of d-mannose does not appear to contain an appreciable
quantity of the furanose modification, but when calcium chloride is
added to the mannose solution and the solution evaporated, d-manno-
furanose calcium chloride crystallizes.
4. CHEMICAL METHODS FOR STUDYING THE EQUILIBRIUM STATE
When a sugar is treated with methyl alcohol in the presence of
hydrochloric acid, the alpha and beta methyl pyranosides and the
alpha and beta methyl furanosides are formed. The furanosides are
formed much more rapidly than the pyranosides, so that with short
treatment at low temperatures, the furanosides predominate, whereas
with longer treatment at higher temperatures, the pyranosides pre-
dominate. Obviously, on account of the equilibrium displacement,
the formation of either the furanosides or the pyranosides does not
give information concerning the equilibrium existing in the original
solution. But under favorable conditions, by consideration of the
mechanism of the reaction and of the rates at which the various modifi-
cations change one into another, one can interpret a chemical reaction
in terms of the equilibrium state. The most extensive investigation
of this character has been made on the oxidation of the sugars with
bromine [36, 37, 38]. In slightly acid solution the pyranose sugars
are oxidized rapidly to delta lactones (as shown by the results given
in [9, 37]), whereas the furanose sugars are oxidized to gamma lactones.
Since the oxidation is rapid in comparison with the rate at which one
modification of the sugar changes to another, the identification of the
oxidation products indicates which substances are present in the equi-
librium solution. The alpha and beta sugars differ widely in their
rates of reaction. The oxidation of the sugar in the equilibrium solu-
tion proceeds rapidly until the easily oxidizable beta modification
is used up, and more slowly as the difficultly oxidizable alpha modi-
fication continues to be oxidized. By comparing the rates of oxidation
of the sugar in the equilibrium solution with the rates for the alpha and
Polarimetry, Saccharimetry, and the Sugars 455
beta modifications as determined separately, it is possible to calculate
the proportions of each modification in the equilibrium solution.
Table 62 gives results of work reported by Isbell [27, 37] and by Isbell
and Pigman [11].
TABLE 62.-Oxidation of sugar solutions at 0° C with bromine water in the presence
of barium carbonate *
Composition of equilibrium solution | ** º §§ bromine
Calculated from g : i.
Estimated from optical rotation, o: #;" Obtained with
Sugar Oxidation meas- assuming only j OnS at crystalline
Sug urement two constitu- o SugarS
0.39 C
entS
More re-
LeSS reac- g Alpha || Beta fe
tive Sugar º Sugar | Sugar kAX103 |k BX103 |kox103 || kg):<10%
gar
Percent | Percent | Percemt| Percent
l-Arabinose-- - - - - - - - - - - - - - - - - - - - - 32.4 67. 6 26. 5 73. 5 84.2 1,608 95.3 1,658
d-Xylose----- - - - - •- -ºs -- *- - - - - - - - - - - - - 32. 1 67.9 b 34.8 b 65. 2 80.3 | 1, 673 89.9 |_ _ _ _ _ _ _ _
d-Lyxose------------------------ 79. 7 20.3 76. 0 24. 0 | 189 717 | 156 449
d-Ribose------ - - - . . . . . . . . . . . . . . . . 89.3 10. 7 --------|-------- 180 1,010 || 196 |_ _ _ _ _ _ _ _
l-Ribose------- - - - - - - - - - - - -- - - - - - - .89. 0 11.0 |--------|-------- 170 1, 456 | 195 || - - - - - - -
l-Rhamnose. - . . . . . . . . . . - - - - - - - - - 69. 0 31. 0 || b 73. 1 b 26.9 83. 4 770 89.7 | -- - - - - - -
d-Glucose------ . . . . . . . . . . . . . . . . . . 37.4 62.6 36.2 63. 8 27. 5 1, 362 32.4 1, 255
d-Mannose- - - . . . . . . . . . . . . . . . . --- 68.9 31. 1 68. 8 31.2 45.2 860 51. 1 781
d-Galactose----. . . . . - - - - - - - - - - - - - - 31.4 68. 6 29. 6 70. 4 37.9 | 1, 720 42. 3 1, 590
d-Talose-------------------.... -- 55.9 44. 1 ||--------|-------- 84.8 844 78.5 |-- - - - - - -
(d-Gulose)2CaCl2.H2O -- . . . . . . . .- 18.5 81.5 ! ... - - - - - ------. - 5.2. 6 418 54.8 328
d-or-Mannoheptose hydrate - - - - - - 32.8 67. 2 || -- - - - - - - - - - - -- - 49, 7 | 1, 556 40.4 1,843
d-6-Guloheptose----------------- 37. 0 63.0 l. - - - - - - - - - - - - - - - 39. 1 1, 779 34. 2 |_
d-6-Galaheptose- - - - - - - - - - - - - - - - - 37.2 62.8 |--------|-------- 25.5 | 1,987 |_ _ _ _ _ _ _ _ 1,696
d-o-Galaheptose hydrate---- - - - - - 79. 4 20.6 |--------|-------- 65. 0 | 1,797 72. 1 |--|-- - - - -
d-or-Glucoheptose---------------- 11.8 88. 2 --------|-------- 44.2 58 -------- 393
d-6-Glucoheptose. --------------- 21.9 78.1 |--------|-------- 30.2 382 | -- - - - - - - 355
Lactose-------------------------- 37.5 62.5 36.8 63. 2 20. 9 1,475 29.3 952
Maltose- - - - - - - - - - - -* * * * ~ * ~ * * * * * * * * 37.7 62. 3 || b 36. 0 || b 64. 0 23. 7 | 1, 388 |-------- 1, 528

* The experimental details for the oxidation measurements are given on p. 173 of reference [11]. Rates
of oxidation were determined in aqueous solutions containing 0.05 mole of sugar per liter, and approximately
0.08 mole of free bromine per liter, and buffered with barium carbonate and carbon dioxide.
b Percentage calculated from Hudson's optical rotations derived from measurements of the initial and
final solubilities at 20° C.
The reaction of the sugars with hydrogen cyanide has been used
for estimating the concentration of the open-chain modifications. It
is assumed that the open-chain modifications of the sugars combine
readily with hydrogen cyanide, whereas the ring modifications do
not. Lippich [39] has shown that each sugar in the equilibrium state
has an initial power for combining with hydrogen cyanide, which he
considers a measure of the amount of the open-chain modification
present in the equilibrium state.
The reaction of the sugars with acetic anhydride in pyridine solution
appears to give some information concerning the modifications
present. Schlubach and Prochownick [40] found, for example, that
the proportions of the pyrano- and furano-acetates of galactose,
formed by acetylation of galactose dissolved in dry pyridine vary with
temperature. The reaction of the sugars with acetone in the presence
of copper sulfate also has been used to show the presence of furanose
modifications [41]. In conclusion, further investigation of the reac-
tion rates and the quantitative determination of the products is
needed to give additional information concerning the equilibrium state.
456 Circular of the National Bureau of Standards
5. REFERENCES
[1] A. P. Dubrunfaut, Compt. rend. 23, 38 (1846).
[2] L. Pasteur, Ann. chim. phys. 31, 67 (1851) Compt. rend. 42, 347 (1856).
[3] E. O. Erdmann, Dissertatio di saccharo lactico et amylaceo cited in Jahres-
bericht für 1855, p. 671.
[4] T. M. Lowry and G. F. Smith, Rapports sur les hydrates de carbone, 10th
Conference of the International Union of Chemistry, p. 79 (Liege, 1930).
[5] C. Tanret, Compt. rend. 120, 1060 (1895); Bul. soc. chim. 15, 349 (1896).
[6] E. F. Armstrong, J. Chem. Soc. 83, 1305 (1903).
[7] W. Gabryelski and L. Marchlewski, Biochem. Z. 261, 393 (1933); see also
L. Marchlewski and W. Urbanczyk, Biochem. Z. 262, 248 (1933).
[8] J. K. Dale, BS J. Research 3, 459 (1929) RP 106.
[9] H. S. Isbell, J. Am. Chem. Soc. 55, 2166 (1933).
[10] H. S. Isbell and W. W. Pigman, J. Research NBS 20, 773 (1938) RP1104.
[11] H. S. Isbell and W. W. Pigman, J. Research NBS 18, 141 (1937) RP969.
[12] C. N. Riiber and J. Minsaas, Ber. deut. chem. Ges. 59, 2266 (1926).
13] G. F. Smith and T. M. Lowry, J. Chem. Soc. 1928, 666.
[14] W. W. Pigam and H. S. Isbell, J. Research NBS 19, 189 (1937) RP1021.
[15] H. S. Isbell, J. Am. Chem. Soc. 56, 2789 (1934).
[16] F. P. Phelps and F. J. Bates, J. Am. Chem. Soc. 56, 1250 (1934).
[17] W. C. Austin and F. L. Humoller, J. Am. Chem. Soc. 56, 1153 (1934).
[18] W. W. Pigman and H. S. Isbell, J. Research NBS 19, 443 (1937) RP1035.
C. S. Hudson, Rapports sur les hydrates de carbone, 10th Conference of the
International Union of Chemistry, p. 65 (Liege, 1930).
[1
9.
(
[20] C. S. Hudson, Z. physik. Chem. 44, 487 (1903).
[21] C. S. Hudson, J. Am. Chem. Soc. 26, 1065 (1904).
[22] T. M. Lowry, J. Chem. Soc. 85, 1551 (1904).
[23] C. S. Hudson, Sci. Pap. BS 21, 268 (1926) S533.
[24] CŞ. Riiber, Saertrykk av Tidsskrift for kjemi og bergvesen, nr. 10 (1932)
. T. nr. 252.
[25] N. A. Sørensen, Kgl. Norske Videnskab. Selskabs, Skrifter, No. 2 (1937).
26] F. P. Worley and J. C. Andrews, J. Phys. Chem. 32, 307 (1928).
27] H. S. Isbell, J. Research NBS 18, 505 (1937) RP990.
28] H. S. Isbell and W. W. Pigman, J. Research NBS 22, 397 (1939) RP1190.
29] C. S. Hudson, J. Am. Chem. Soc. 31, 66 (1909).
30] H. T. Brown and S. U. Pickering, J. Chem. Soc. 71, 756 (1897).
[31] J. N. Brönsted and E. A. Guggenheim, J. Am. Chem. Soc. 49, 2554 (1927).
[32] H. S. Isbell (heretofore unpublished work).
[33] T. M. Lowry and I. J. Faulkner, J. Chem. Soc. 127, 2883 (1925).
[34] H. S. Isbell, BS J. Research 5, 741 (1930) RP226.
[35]. H. S. Isbell and H. L. Frush (heretofore unpublished work).
[36] H. S. Isbell and C. S. Hudson, BS J. Research 8, 327 (1932) RP418.
[37] H. S. Isbell, BS J. Research 8, 615 (1932) RP441.
[38]. H. S. Isbell and W. W. Pigman, BS J. Research 10, 337 (1933) RP534.
[39] F. Lippich, Biochem. Z. 248, 280 (1932).
[40] H. H. Schlubach and V. Prochownick, Ber. deut. chem. Ges 62, 1502 (1929).
[41] H. Ohle, Die Chemie der Monosaccharide und der Glykoside, p. 126 (J. F.
Bergmann, Munich, 1931).
XXX. METHODS FOR THE PREPARATION OF CERTAIN
SUGARS
The methods reported here are those ordinarily used in the labo-
ratories of the National Bureau of Standards for the preparation of
the various sugars. No attempt has been made to give a complete
bibliography or to record the contributions of the various workers
in the field. Some of the methods are essentially as given in the
reference cited, while others have been improved in various ways.
1. d-ALLOSE
Method."—[1, 2, 3]". Fifty grams of purified d-allonic lactone
and 500 ml of distilled water are placed in a 1.5-liter wide-mouthed
43 In chapters XXX and XXXI the superscript numbers refer to the numbered notes, and the numbers
in brackets refer to literature reference numbers at the end of each section.
Polarimetry, Saccharimetry, and the Sugars 457
flask or beaker. The solution is stirred vigorously and cooled in an
ice-and-salt bath so that a little ice forms inside the beaker (to be
sure that the solution is actually at about 0°C). About 4 ml of dilute
(10-percent) sulfuric acid is added, and then 2.5-percent sodium amal-
gam in 250-g portions, while dilute sulfuric acid is continuously
dropped from a burette at such rate that the solution remains just
barely acid to congo-red test paper.” After the addition of 3 or 4
portions of amalgam during the course of approximately 1 hour, the
sugar content reaches a maximum. The solution is poured off from
the mercury and treated with enough sodium carbonate so that
after standing about 9% hour (cold) the reaction mixture is still slightly
alkaline.* Dilute sulfuric acid is added until the solution is slightly
acid to litmus; it is then evaporated in vacuo to a small volume.
Alcohol is added until further addition causes no further precipitate,
the solution is filtered, and the alcoholic filtrate evaporated to a thick
sirup. Upon extraction of the sirup with hot absolute alcohol, the
allose dissolves, leaving sodium allonate as a sticky gum. Evapo-
ration of this alcoholic extract yields crystalline allose.
The crude product may be purified by dissolving it in a little warm
water, adding 3 volumes of warm methyl alcohol, and filtering through
a little decolorizing carbon. The filtrate is allowed to cool and is
seeded with crystalline allose. After standing for several hours, the
crystalline product is separated.
NOTES
* The same procedure may be used for the preparation of altrose and other
Sugars. -
* The preparation of allonic lactone from ribose is described on page 527.
* The solution should be kept cold and the acidity should be carefully watched.
* The purpose of the sodium carbonate treatment is to convert all unreduced
lactone to the sodium salt in order to facilitate its removal by alcohol.
REFERENCES
[1] F. P. Phelps and F. J. Bates, J. Am. Chem. Soc. 56, 1250 (1934).
[2] W. C. Austin and F. L. Humoller, J. Am. Chem. Soc. 55, 2167 (1933).
[3] W. C. Austin and F. L. Humoller, J. Am. Chem. Soc. 56, 1153 (1934).
2. l-ARABINOSE
Method.”—[1] Three kilograms of mesquite gum * is dissolved in 11
liters of water.” Two liters of a solution containing 370 ml of con-
centrated sulfuric acid is added, and the solution is kept for 7 hours at
a temperature of 80° to 90° C. The hot solution is neutralized with
about 700 g of calcium carbonate,” and the insoluble material is
removed by filtration. To the filtrate is added 1 kg of decolorizing
carbon.” After several hours the solution is filtered and the filtrate
evaporated in vacuo to a volume of 4 liters. Twelve liters of hot
ethyl alcohol is now added and the two phases are thoroughly mixed."
The gummy material is allowed to settle out for several hours while
the liquid cools. The supernatant liquid is separated by decantation.
The gums are given a second and third extraction, each time with 6
liters of warm methyl alcohol. The alcoholic extracts are combined
and concentrated in vacuo to a thin sirup which is allowed to crystal-
lize. About 900 g of crude arabinose is obtained in the first crop and
250 g of additional material may be separated by concentrating the
458 Circular of the National Bureau of Standards
mother liquors, removing the gummy impurities by precipitation
with hot ethyl alcohol and evaporating the alcoholic extract."
Recrystallization.—Crude arabinose which contains gums may be
purified in the following manner: 300 g of the sugar is dissolved
by heating with 100 ml of water; the solution is mixed with
750 ml of hot ethyl alcohol and 15 g of a decolorizing carbon. The
hot solution is filtered, and the carbon residue is washed with 150 ml
of hot ethyl alcohol. The hot filtrate is allowed to cool, and accidental
seeding with crystalline arabinose is avoided. As the solution cools
it separates into two phases, the lower more sirupy layer of which
contains most of the impurities. After the solution reaches room
temperature and the sirupy phase has settled, the alcoholic layer is
decanted. The residue is extracted as before with 300 ml of hot
methyl alcohol, followed by 300 ml of hot ethyl alcohol. The com-
bined alcoholic extract is evaporated in vacuo to a volume of approx-
imately 600 ml. Sometime before this volume is reached, crystalli-
zation takes place in the distillation flask. When the evaporation
has reached the desired stage, the sirup is seeded with crystalline
arabinose, placed in the refrigerator, and allowed to stand until a
satisfactory crystal growth is obtained. The first crystals are usually
about 60 percent of the arabinose content. By concentrating the
mother liquors, additional crystalline sugar is obtained.
Relatively pure arabinose can also be recrystallized in the following
manner: 300 g of arabinose is dissolved with 180 ml of water. The
hot solution is mixed with 200 ml of hot methyl alcohol, and after the
addition of 50 g of a decolorizing carbon the mixture is filtered rapidly
while hot. The filtrate is diluted with 400 ml of methyl alcohol and
300 ml of ethyl alcohol, cooled to room temperature, seeded, and set
aside to crystallize. After several days the resulting crystals are
collected on a filter and washed with methyl alcohol. The yield is
about 150 g. . The sugar in the mother liquors is reclaimed by evaporat-
ing the liquors to a sirup (n?=1.465), which, after mixing with about
5 volumes of methyl alcohol, yields additional crystalline sugar.
In 4-percent aqueous solution, 6-l-arabinose gives [o]}= + 190.6°
initially, which changes in the course of several hours to +104.5°.
NOTES
1 The method is that of Anderson and Sands [1] as modified by Isbell (heretofore
unpublished work).
2 Mesquite gum is obtained from a plant (Prosopis juliflora and related species)
widely distributed through the southwest. It may be purchased from the
Martin Drug Co., Tucson, Ariz. Cherry gum may also be used with essentially
the same procedure.
3 The gum requires about 24 hours to dissolve. Before starting the hydrolysis,
it is well to filter the solution through cheese cloth in order to remove bark and
other foreign matter.
* This must be done slowly with small portions of calcium carbonate. Foaming
may be reduced by the addition of a commercial antifoam agent or capryl alcohol.
* The exceptionally large quantity of decolorizing carbon is added to reduce
foaming, which can be further reduced by the use of an antifoam agent such as
capryl alcohol.
6 A mechanical stirrer is of considerable help in this procedure.
7 l-Arabinose has been prepared from a number of other sources: Cherry gum [2],
wheat and rye bran [3,4], peach gum [5], Australian black wattle gun [6], and beet
pulp [7]. Harding [8] gives a review of the sources.
Polarimetry, Saccharimetry, and the Sugars 459
REFERENCES
[1] E. Anderson and L. Sands, J. Am. Chem. Soc. 48, 3172 (1926), also, Organic
Syntheses 8, 18 (1928). -
] H. Kiliani, Ber. deut. chem. Ges. 19, 3029 (1886).
} W. Stone and B. Tollens, Liebigs Ann. Chem. 249, 238 (1888).
] E. Steiger and E. Schulze, Ber. deut. chem. Ges. 23, 3110 (1890).
| W. Stone, Am. Chem. J. 12, 435 (1890).
| W. Stone, Am. Chem. J. 17, 196 (1895).
| E. Zitkowski, Am. Sugar Ind. 13, 98 (1911).
] T. S. Harding, Sugar 24, 656 (1922).
3. CELLOBIOSE (4-(6-d-GLUCOPYRANOSIDO)-d-GLUCOSE)
Method.—The octaacetyl cellobiose is prepared by the action of
acetic anhydride and sulfuric acid on cotton or filter paper according
to the method of Klein [1]." Fifty grams of pure cotton is put in a
precipitating jar (about 12 cm in diameter and 25 cm high), which is
cooled in an ice-and-salt bath. Acetic anhydride, 140 ml, is added and
the jar covered with a watch glass. Sixty milliliters of acetic anhy-
dride is cooled in an ice-and-salt bath and 28 ml. of sulfuric acid
slowly added. When this solution has cooled, it is poured onto the
cold mixture of cotton and acetic anhydride and the whole mixture
worked to a homogeneous mass by stirring with a glass rod. The
Cotton gradually disintegrates. The mass is transferred to a 2-liter
Erlenmeyer flask and after vigorous shaking and occasional heating on
the steam bath, a reddish solution is obtained.” Several such batches
combined are allowed to stand at room temperature for 2 or 3 days
while crystallization takes place. The crystalline mass is not poured
into water, as described by Klein, but filtered on a large-size Büchner
filter having small holes, and fitted with a double layer of ordinary
filter paper. It is filtered dry and washed with ether. The product
is now stirred in a dish with 95-percent alcohol, again filtered by
suction, and finally recrystallized from 95-percent alcohol. The
yield may reach 40 to 50 percent of the theoretical. In a 2.5-percent
concentration in chloroform the specific rotation of the pure substance
is [o]}= +41.5°, and the melting point is 229.5°C.
The cellobiose octaacetate is deacetylated by dissolving it in dry
methyl alcohol and adding 1 ml of 0.5 N barium methylate * solution
for each gram of sugar. After standing overnight in the refrigerator,
the barium is removed by precipitation with an equivalent quantity
of sulfuric acid and the barium-free solution is concentrated in vacuo
to a thin sirup which on standing yields crystalline cellobiose.
Anhydrous 6-cellobiose melts at 225°C and gives [o]}= + 14.2°
initially, which changes in the course of several hours to +34.6°.
NOTES
1 The simultaneous hydrolysis and acetylation of cellulose was described first
by Franchimont [2]. Modifications of the original method are described in
references [3, 4, 5, and 6].
* This part of the preparation requires some practice in order to obtain uniform
results. Several batches may be prepared in this way and combined in the next
step, but it is not advisable to work with larger amounts up to this point, as char-
ring may result.
3 The preparation of the barium methylate solution and additional details for
the method are given on page 493.
460 Circular of the National Bureau of Standards
REFERENCES
Rlein, Z. angew. Chem. 25, 1409 (1912).
P. N. Franchimont, Ber. deut. chem. Ges. 12, 1941 (1879).
H. Skraup, Ber. deut. chem. Ges. 32, 24.13 (1899).
Zemplén, Ber. deut. chem. Ges. 59, 1258 (1926).
Braun, Organic Syntheses 17, 36 (1937).
C. Spencer, Cellulosechemie 10, 61 (1929).
1] F.
2] A.
3] Z.
4] G.
5] G.
6] C.
4. 2-DESOXY GALACTOSE
Method.—[1, 2, 3] Fifty grams of recrystallized galactal is dissolved
in 700 ml of 5-percent cold sulfuric acid, and the solution is kept in
the refrigerator at 0°C for 24 hours, after which it is neutralized with
120 g of barium carbonate and the esters are saponified by heating to
60° C. The saponification usually requires about 48 hours of heating.
Eight- or ten-gram portions of barium carbonate are added at inter-
vals during this time. The solid material is separated by filtration,
and the filtrate is evaporated in vacuo to a thick sirup which is taken
up with 50 ml of absolute alcohol and allowed to crystallize. About
40 g of material is obtained.”
The crystals are purified by dissolving in water and evaporating
the solution to a sirup, which is taken up with three volumes of methyl
º and allowed to crystallize, preferably in a slowly rotating
8,SEK.
Desoxygalactose melts at 120° to 121° C. In 4-percent aqueous
solution, desoxygalactose gives [o]*= +40.8° initially, which decreases
in 5 minutes to a minimum and then increases to +60.5° in about 30
minutes.
NOTES
* The preparation of galactal is described on page 532.
* The preparation of 2-desoxyglucose and 2-desoxyrhamnose is given by Berg-
mann, Schotte, and Leschinsky [3], while that of 2-desoxyarabinose and desoxy-
xylose is described by Levene and Mori [4]. Several natural-occurring desoxy
sugars are reported [5, 6, 7].
REFERENCES
| H. S. Isbell and W. W. Pigman, J. Research NBS 22, 397 (1939) RP1190.
| P. A. Levene and R. S. Tipson, J. Biol. Chem. 93, 644 (1931).
| M. Bergmann, H. Schotte, and W. Leschinsky, Ber. deut. chem. Ges. 55, 158
(1922); 56, 1052 (1923).
P. A. Levene and T. Mori, J. Biol. Chem. 83, 803 (1929).
H. Kiliani, Ber. deut. chem. Ges. 38, 4040 (1905).
A. Windaus and L. Hermanns, Ber. deut. chem. Ges. 48, 88 (1915).
W. A. Jacobs and N. W. Bigelow, J. Biol. Chem. 96, 355 (1932).
1.
2
3
4
5
6
7
|
5. l-FUCOSE (l-GALACTOMETHYLOSE)
Method.”—[1, 2, 3] The seaweed, ascophyllum nodosum, is washed
with tap water and any large shells are removed. It is then air-dried
and ground to a fine powder. One kilogram of the dried seaweed is
added to 8 liters of hot 4-percent sulfuric acid, and the solution is
allowed to simmer for 3 hours. The liquid is separated by filtration
and the residue is washed with hot water. The filtrate is neutralized
with an excess of calcium carbonate, refiltered, and the calcium
sulfate washed with water. The mixture is cooled to room tempera-
ture and fermented with baker's yeast acclimatized to ferment
galactose.” When the fermentation is complete, about 100 g of a
decolorizing carbon is added; and after standing for several hours, the
Polarimetry, Sacchari metry, and the Sugars 461
solution is filtered and concentrated in vacuo to about 2.5 liters. The
precipitated calcium sulfate is separated, and the filtered solution is
concentrated to a sirup (nº=1.48). The sirup is mixed with 1 liter of
hot methyl alcohol; the insoluble residue is separated and washed with
three 100-ml portions of hot methyl alcohol. The residue is discarded,
and the alcoholic extract is purified by adding 600 ml of ether and
separating the precipitate by filtration. The solution is concentrated
to a thick sirup (nº= 1.50), which is taken up in 200 ml of hot absolute
alcohol. The alcoholic solution is filtered and then mixed with 75 ml
of phenylhydrazine. After standing for 1 or more days in the refrig-
erator, the crystalline hydrazone is collected on a filter, washed with
absolute alcohol, and dried at 50° C. The hydrazone (100 g) is
transferred to a flask containing 50 ml of benzaldehyde and 2 liters of
hot water. The mixture is stirred and heated to about 90°C for about
1 hour, after which it is cooled to room temperature. After the addi-
tion of 10 g of a decolorizing carbon, the benzaldehyde phenylhy-
drazone is separated by filtration. The filtrate is extracted three times
with 100-ml portions of ether to remove all of the benzaldehyde. The
solution is then made acid with acetic acid and concentrated to a sirup
of about 80 percent of total solids. This sirup is diluted with about
50 ml of absolute alcohol and seeded with crystalline fucose. After
this solution has stood for 1 or more days in the refrigerator, the result-
ing crystals are separated and washed with absolute alcohol. The
yield is about 30 g.
Recrystallization.—The sugar is dissolved in approximately an
equal quantity of hot water, and after treatment with a decolorizing
carbon, is filtered. The solution is made acid with acetic acid and
concentrated in vacuo to a sirup of about 80 percent of total solids
(m33–1.490). This sirup is diluted with 2 ml of absolute alcohol for
each gram of sugar and placed in the refrigerator for crystallization to
take place. The resulting crystals are collected on a filter and washed
with 95-percent alcohol. The mother liquors are concentrated and
additional crystals are separated so that nearly all of the sugar is
reclaimed. Better purification but lower yields are obtained by
crystallizing the sugar from an aqueous solution contained in a flask
which is slowly rotated. A solution containing approximately 78
percent of sugar by weight gives a satisfactory crystallization.
In 4-percent aqueous solution l-fucose gives [a]*=–152.6° initially,
which changes in the course of several hours to —75.9°.
NOTES
1 The method is essentially that described by Tollens and coworkers [1] as
modified by Clark [2] and by Hockett, Phelps, and Hudson [3].
* The fermentation removes mannose and galactose, which are present in certain
seaweeds [4].
REFERENCES
[1] J. A. Widtsoe and B. Tollens, Ber. deut. chem. Ges. 33, 132 (1900); A. Günther
and B. Tollens, Liebigs Ann. Chem. 271, 86 (1892).
[2] E. P. Clark, BS Sci. Pap. 18, 527 (1922) S459; J. Biol. Chem. 54, 65 (1922).
[3]
(1939)
E
R. C. Hockett, F. P. Phelps, and C. S. Hudson, J. Am. Chem. Soc. 61, 1658
R. H. F. Manske, J. Biol. Chem. 86, 571 (1930).
323414°–42——31
462 - Circular of the National Bureau of Standards
6. d-GALACTOSE
Method.—[1] Fifteen hundred grams of lactose is dissolved in 3,750
ml of hot water containing 75 g of concentrated sulfuric acid. The
solution is brought to a boil and then simmered for 2 hours. A thin
paste of barium carbonate is then added to the hot solution until it
reacts neutral to congo-red paper. The precipitate of barium sulfate
is allowed to settle, after which as much as possible of the supernatant
liquid is drawn off and filtered. Then the precipitate is placed on the
filter and washed with water. The filtrate is concentrated under
diminished pressure until it has a weight of about 1,650 g (nº between
1.5120 and 1.5125). The very thick sirup is warmed to between
60° and 70°C, and 250 ml of ethyl alcohol is dissolved in it by vigorous
shaking. The solution is then poured into a beaker or jar and the
remaining sirup is washed from the flask with 500 ml of methyl
alcohol. This is best done by adding the methyl alcohol to the flask
portionwise and warming and shaking in a water bath. The whole
solution is thoroughly mixed, seeded with some pure galactose crystals,"
and allowed to crystallize, preferably in a slowly rotating flask.
The crystallization is generally complete in about 4 days, after
which the crystals are filtered off, washed with a little methyl alcohol,
and dried. The yield of the crude sugar is about 27 percent of the
lactose taken.”
Recrystallization.—The crude galactose is dissolved in an equal
weight of hot water, and after the addition of a small quantity of a
decolorizing carbon the solution is filtered. A few drops of acetic
acid are added, and the solution is evaporated in vacuo to a sirup of
60 percent of total solids (mº- 1.442). The sirup is then seeded with
o-d-galactose and kept in motion * while crystallization proceeds.
When a satisfactory crystal growth is obtained (in about 1 day), the
crystals are separated either by filtration or by means of a centrifuge.
The crystals are washed thoroughly with methyl alcohol. About 50
percent of the sugar is obtained in the first crop, and the remainder
may be separated by concentration of the mother liquor.
A more rapid recrystallization can be made by dissolving 200 g of
galactose in 100 ml of water, filtering the solution with the addition of
about 5 g of a decolorizing carbon, and adding 100 ml of methyl
alcohol. The mixture is seeded and stirred while crystallization
takes place. After several hours the crystalline galactose is separated
by filtration and washed with methyl alcohol. About 75 percent of
the original sugar is obtained in the first crop of crystals; the rest of
the sugar is reclaimed by concentrating the mother liquor.
In 5-percent aqueous solution, pure o-d-galactose has an initial
specific rotation, [o]}= +150.7°, which changes after a number of
hours to the equilibrium value, --80.2°.
NOTES
1 Contamination by dextrose seed must be avoided.
* If the hydrolysis is not complete, unchanged lactose may be obtained. Also
dextrose may occasionally crystallize simultaneously with the galactose.
* Galactose may be prepared from plant gums, such as those from the western
larch [2] and by partial fermentation of the hydrolysis products of lactose [3].
A review of methods for the preparation of galactose is given by Harding [4].
* If the solution is not kept in motion, the crystals form a solid mass.
Polarimetry, Saccharimetry, and the Sugars 463
REFERENCES
E. P. Clark, BS Sci. Pap. 17, 227 (1922) S416.
A. W. Schorger and D. F. Smith, J. Ind. Eng. Chem. 8, 494 (1916). U. S.
Patent 1,358,129 and British Patent 160,776.
] G. Mougne, Bul. soc. chim. biol. 4, 206 (1922).
] T. S. Harding, Sugar 25, 175 (1923).
7. GENTIOBIOSE (6-(6-d-GLUCOPYRANOSIDO)-d-GLUCOSE)
Method.—[1] Gentiobiose is conveniently prepared from the sirupy
residue left from the preparation of dextrose from starch. About 4.5
kg of this residue called “hydrol” is dissolved in 30 liters of water,
and after the addition of 100 g of calcium carbonate and 2 cakes of
baker's yeast the mixture is allowed to stand until fermentation is
complete. About 750 g of a decolorizing carbon is added and the
solution is filtered. The filtrate is evaporated under reduced pressure
to a thick sirup of about 80 percent of total solids (mº- 1.490).
The sirup is taken up with 8 liters of a hot mixture of methyl and
ethyl alcohols (7 parts of methyl to 1 part of ethyl alcohol). The
granular precipitate is extracted several times with methyl alcohol,
and the combined extracts are again evaporated to a thick sirup
(nº=1.510). This is mixed with 2 liters of glacial acetic acid and
evaporated in vacuo until the solvent ceases to distill. The sirup,
weighing 1,300 g and contained in a 12-liter flask, is heated with 500 ml
of technical acetic anhydride until a slow visible reaction starts.
Twenty grams of anhydrous sodium acetate * is introduced, and the
mixture is heated with stirring until the reaction becomes vigorous.
The source of heat is then removed and care must be taken to keep the
reaction from becoming too violent. When the reaction has slowed
down, more acetic anhydride (500 ml) and sodium acetate (20 g) are
added. The addition is repeated until a total of 4,000 ml of the
acetic anhydride and 350 g of sodium acetate has been introduced.”
Heating is then continued for 1 more hour. The solution, after
cooling, is poured into 15 liters of water. The insoluble phase is
separated by decantation and given several washings with water.
The combined water washings are extracted with chloroform to recover
any dissolved or suspended product. After evaporation of the
chloroform, the residue is combined with the water-insoluble portion
and stirred a second time with water. After several hours theinsoluble
material is separated again and then dissolved in ether and kept at
0° C until crystals of gentiobiose octa-acetate form. This may require
1 or more weeks; hence it is advisable to seed the product with crystal-
line gentiobiose octa-acetate. Several days after seeding, the crystal-
line material is separated by filtration, washed with alcohol, and
dried.* The yield is about 100 g. The crude gentiobiose octa-acetate
is recrystallized by dissolving in boiling ethyl alcohol, adding a decol-
orizing carbon, filtering, and allowing the solution to cool. The
ºlized material weighs 80 g and has a melting point of 193° to
196° C.
The gentiobiose octa-acetate is deacetylated by the barium methy-
late method of Isbell. Eighty grams is dissolved in 6 liters of dry
methyl alcohol with the aid of heating. The solution is cooled to
room temperature, 100 ml of 0.6 N barium methylate in dry methyl
alcohol is added, and the solution is kept at 0°C for 48 hours, after
which the barium is precipitated by sulfuric acid or carbon dioxide
464 Circular of the National Bureau of Standards
and removed by filtration. The solution, free from barium, is con-
centrated under reduced pressure to a thick sirup which is taken up
with methyl alcohol. Crystallization usually takes place in several
hours. The crystals when separated weigh about 33 g, and about 15 g
more are obtained from the mother liquors.”
Recrystallization.—Purification is accomplished by dissolving the
material in water, treating with a decolorizing carbon, filtering, and
concentrating to a heavy sirup (nº=1.515) which is dissolved in
methyl alcohol " and allowed to crystallize.
The isomer obtained in this way has the formula, cº-gentiobiose
.2CH3OH. The melting point is 86° C, and the initial rotation,
[a]}= +21.4°, changes to the equilibrium value, [o]*}= +8.7° (as
alcoholate).
NOTES
1 “Hydrol” may be obtained from the concerns manufacturing dextrose.
* Anhydrous sodium acetate is prepared by fusing the hydrate in an iron
crucible. See p. 488, note 1.
3 The reaction takes place much less violently as the addition proceeds, and
the materials may be added at short intervals after the third or fourth addition.
4 The alcohol washings should be kept separate from the mother liquor, which
usually does not yield any further material.
* Gentiobiose may be prepared from gentian root [2, 3, 4] or synthesized by the
method of Reynolds and Evans [5].
6 Methyl alcohol is the only alcohol which should be used, since the sugar
crystallizes as the difficultly soluble methyl alcoholate.
REFERENCES
[1] H. Berlin, J. Am. Chem. Soc. 48, 2627 (1926).
[2] C. S. Hudson and J. Johnson, J. Am. Chem. Soc. 39, 1272 (1917).
[3] G. Zemplén, Z. physiol. Chem. 85, 399 (1913); Ber. deut. chem. Ges. 48, 233
(1915).
[4] E. Bourquelot and H. Hérissey, Compt. Rend. 132, 571 (1901); 135, 290
(1902
[5] D. D. Reynolds and W. L. Evans, J. Am. Chem. Soc. 60, 2559 (1938).
8. 4-GLUCOSIDOMANNOSE, (4-(6-d-GLUCOPYRANOSIDO)-d-MANNOSE)
Method.—[1,2]. Six grams of octaacetyl-4-glucosidomannose is
dissolved in 150 ml of absolute methyl alcohol, and the solution treated
with 5 ml of about 0.5 N barium methylate solution.” After 24 hours
the barium is removed by adding an equivalent quantity of sulfuric
acid “ and filtering. The filtered solution is evaporated in vacuo to a
thick sirup which is taken up with 10 ml of ethyl alcohol. About 2.4
g of crystalline 4-glucosidomannose separates in the first crop, and a
small amount (0.2 g) is obtained from the mother liquor. The sugar
crystallizes in the alpha modification as a monohydrate which melts
at 137° C.4
In 4-percent aqueous solution, 4-(6-d-glucosido)-o-d-mannose
hydrate gives [o] }= + 14.7° initially, which changes in the course of
several hours to +5.9°. - -
NOTES
* The preparation of octaacetyl-4-glucosidomannose is given on page 501.
* The barium methylate solution is prepared by adding 125 g of powdered
barium oxide to 500 ml of absolute methyl alcohol. After standing for several
hours, the solution is filtered. It should be kept in a bottle protected from moisture
and carbon dioxide. * . * *
* Since moisture or acids in the original sirup will decompose the barium methyl-
ate, it is well to test the deacetylated mixture to see if an excess of barium methylate
Polarimetry, Saccharimetry, and the Sugars 465
is present. This may be done by diluting a few milliters with water and adding
Several drops of phenolphthalein solution. A definite red color indicates a suffi-
cient excess. If the test is not positive, add more barium methylate solution to the
deacetylation mixture and allow 24 hours more for the deacetylation to
be completed.
* Glucosidomannose has been made by the oxidation of cellobial with perbenzoic
acid [3,4]. The method as applied to d-talose is given on page 479.
REFERENCES
D. H. Brauns, J. Am. Chem. Soc. 48, 2776 (1926).
H. S. Isbell, BS J. Research 5, 1179 (1930) RP253; 7, 1115 (1931) RP392.
M. Bergmann and H. Schotte, Ber. deut. chem. Ges. 54, 1570 (1921).
W. N. Haworth, E. L. Hirst, H. R. L. Streight, H. A. Thomas, and J. Webb,
J. Chem. Soc. 1930, 2636. s:
9. oſ-d-GULOSE. CaCl2.H2O
Method.—[1] Pure d-gulonic gamma lactone is reduced by sodium
amalgam in a 6-liter stainless-steel pot equipped with a strong mechani-
cal stirrer with broad metal paddle and cooled by a mixture of ice and
salt. The lactone (90 g) is dissolved in 800 ml of water and 150 ml
of 95-percent ethyl alcohol, and cooled to about — 10° C. About 14
ml of 20-percent sulfuric acid is added to the solution, followed by
1,500 g of 3-percent sodium amalgam, which is added (in 1 portion)
with vigorous stirring." Twenty-percent aqueous sulfuric acid is
added to the mixture at such rate as to maintain the solution acid
at about pH 3.” After the sodium amalgam has reacted, the mixture
is transferred to a separatory funnel and the mercury is separated.
The solution is returned to the pot used for reduction, and after
cooling to about — 10°C, a second 1,500-g portion of sodium amalgam
is added and the reduction continued while the solution is kept
acid and cold as before. When the amalgam is spent, the mixture is
again transferred to a separatory funnel and the mercury is separated.
The cold solution is filtered to remove the crystalline sodium sulfate,
and sodium hydroxide is added to the filtrate in sufficient quantity
to neutralize the excess acid and to saponify any gulonic lactone.
After the lactone is saponified, as shown by an alkaline reaction after
standing for 15 minutes, the solution is acidified with dilute sulfuric
acid and evaporated under reduced pressure until the formation
of crystalline sodium sulfate causes difficulty with further evapora-
tion. The concentrated liquor is mixed with 2 volumes of ethyl
alcohol and allowed to stand for several hours, preferably in a refriger-
ator. The insoluble salts are separated from the alcoholic solution
by filtration and then washed with methyl alcohol. The alcoholic
solution is evaporated to a thick syrup. This is mixed with 500 ml
of hot ethyl alcohol, which results in the precipitation of most of
the salt in the form of an amorphous residue. Most of the sugar is
found in the alcoholic solution; that which remains in the residue
may be separated by dissolving the residue in water and reprecipi-
tating the salt by the addition of alcohol. The combined alcoholic
solutions are evaporated in vacuo to a heavy sirup. The crude
gulose may be purified by means of its phenylhydrazone or the
product may be converted to d-gulose calcium chloride without
further purification.” The calcium chloride compound is prepared
by adding in aqueous solution approximately 1 molecular equivalent
of calcium chloride. The aqueous solution is evaporated in vacuo
466 Circular of the National Bureau of Standards
to a thick sirup, from which crystalline gulose CaCl2.H2O or (gulose)--
CaCl2.H2O crystallizes readily. The crystalline massecuite is dilut-
ed with a small quantity of ethyl alcohol before filtration, and the
crystals are washed with ethyl alcohol. After further concentration
the mother liquors give additional product. In all, about 70 g of
gulose.CaCl2.H2O is obtained.
In 68-percent aqueous solution, a-d-gulose.CaCl2.H2O gives
|o]}=-|-37.1°, changing to an equilibrium value of –10.0°.
FIGURE 110.-Apparatus used for the reduction of sugar lactones with sodium
amalgam.
NOTES
| Best results are obtained with hard amalgam in pieces about 4 cm in diameter.
* The reaction can be followed by using thymol-blue or congo-red paper as an
outside indicator. Thymol-blue paper should turn pink and congo-red paper
should turn purple.
* In order to obtain gulose. CaCl2.H2O free from sodium salts, it is necessary
to remove all sodium salts before adding the calcium chloride. This is most
readily accomplished by the intermediate preparation of the phenylhydrazone.
REFERENCES
[1] H. S. Isbell, BS J. Research 5, 741 (1930) RP226.

Polarimetry, Saccharimetry, and the Sugars 467
10. LACTOSE (4-(6-d-GALACTOPYRANOSIDO)-d-GLUCOSE)
Method.—This disaccharide is available at a low price as a commer-
cial product which is prepared from the whey obtained from the manu-
facture of cheese. Details of the method are described by Naben-
hauer [1] and are included in the United States Dispensatory [2].
The usual commercial product is o-lactose.H2O, but the much more
soluble anhydrous 8-lactose is also available in large quantities.
Methods for preparing 6-lactose are reviewed by Bell [3].
Recrystallization.—One kilogram of lactose hydrate is dissolved in
750 ml of hot water. After the addition of 20 g of a decolorizing carbon
the hot solution is filtered. The clear filtrate is allowed to cool slowly
with stirring. After several hours at room temperature the crystals
which separate are collected on a filter and washed, first with a
mixture of equal volumes of water and methyl alcohol, and then with
undiluted methyl alcohol. The first crop of crystals is about 65
percent of the crude product. The remaining sugar is reclaimed by
evaporating the mother liquor in vacuo.
Crystalline o-lactose hydrate in 7.6-percent aqueous solution gives
[o]}= +85.0° initially, changing in several hours to +52.6°.
REFERENCES
[1] F. P. Nabenhauer, Ind. Eng. Chem. 22, 54 (1930).
[2] United States Dispensatory, 22d ed., p. 589 (1937).
[3] R. W. Bell, Ind. Eng. Chem. 22, 51 (1930).
11. LACTULOSE (4-(6-d-GALACTOPYRANOSIDO)-d-FRUCTOSE)
Method.—[1] A solution containing 1,200 g of commercial lactose' in
6 liters of water saturated with calcium hydroxide at 35° C is kept at
approximately 35° C for several days or until the optical rotation
shows no further change.” Subsequently the solution is concentrated
in vacuo until the weight is reduced to about 1,500 g. The resulting
residue, which contains considerable crystalline lactose, is diluted
with 1,500 ml of methyl alcohol and allowed to stand in a cold place
for several days for the crystallization of any unchanged lactose.
The crystalline lactose (about 800 g) is separated by filtration and
washed with 450 ml of methyl alcohol. The filtrate is concentrated
in vacuo to a sirup which is diluted with 600 ml of water and evaporated
again to remove the alcohol. The alcohol-free solution is diluted
with water to a volume of 2.5 liters, and the quantity of bromine
necessary to oxidize the aldoses to aldonic acids is ascertained in the
following manner:
A 5-ml sample of the soution is placed in a 200-ml Erlenmeyer
flask and 5 ml of 0.1 N iodine is added from a burette; 7.5 ml of 0.1 N
sodium hydroxide is then added dropwise. The addition of alkali
and iodine is repeated until 30 ml of iodine and 45 ml of alkali have
been added. The solution is acidified with 10 ml of 1 N hydro-
chloric acid and the excessiodine titrated with 0.1 N sodium thiosulfate
using starch indicator. The iodine titration of the sample is the
difference between the quantity of 0.1 N iodine added and the back
titration.” If the volume of the sugar solution is 2.5 liters, the bro-
mine in hydrogen equivalents * is one twentieth of the iodine titration
of the 5-ml sample. Before adding the bromine, sufficient calcium
carbonate is added to combine with the acids formed by the oxidation;
468 Circular of the National Bureau of Standards
this requires 75 g for each equivalent of bromine. The calculated
quantity of bromine is then placed in a dropping funnel and added
drop by drop over a period of several hours while the solution is mixed
with a mechanical stirrer. After all of the bromine has been added,
the mixture is allowed to stand for several hours. About 20 g of a
decolorizing carbon is then added and the solution is filtered. The
bromides in the filtrate are precipitated by mixing with finely pow-
dered silver sulfate,” using 160 g for each equivalent of bromine. The
resulting precipitate is separated by filtration and washed with water.
The bromide-free filtrate is then treated with hydrogen sulfide to precipi-
tate the excess silver. The resulting silver sulfide is removed by fil-
tration, and the filtrate is then evaporated to a volume of about
1,500 ml in vacuo to remove the excess hydrogen sulfide. The solu-
tion is neutralized with calcium carbonate, filtered and evaporated to a
sirup of approximately 75 percent of total solids (n?=1.477). The
sirup is mixed with 1,200 ml of hot methyl alcohol and separated into
methyl alcohol-soluble and alcohol-insoluble material. The alcohol-
insoluble material is given a second and a third extraction with 300-
ml portions of methyl alcohol, and it is then discarded. The com-
bined alcoholic extract is diluted with 900 ml of 95-percent ethyl
alcohol, and the resulting amorphous precipitate is allowed to settle.
The clear alcoholic solution is decanted, and the gummy residue is
extracted with 100 ml. of methyl alcohol. The residue is discarded,
The alcoholic solution is combined with the alcoholic extract previously
obtained, and the mixture is then evaporated in vacuo to a sirup of
about 85 percent of total solids (m?= 1.503). This sirup is mixed
with 300 ml of methyl alcohol, and then absolute ethyl alcohol is
added in sufficient quantity (about 200 ml) to Saturate the sirup
without giving two liquid phases. The alcoholic solution is seeded
with crystalline lactulose and allowed to stand for crystallization.
After several days the crystalline lactulose is separated by filtration.
The mother liquor after concentration, extraction with methyl alco-
hol, and subsequent evaporation yields additional lactulose. A total
of about 180 g of crystalline lactulose is obtained.
Recrystallization.—One hundred grams of crude lactulose is dissolved
in hot water and the solution is filtered, using a small quantity of a
decolorizing carbon. The filtrate is evaporated to a thick sirup
containing about 85 percent of total solids (n?=1.503). The sirup is
mixed with 200 ml of warm methyl alcohol and after cooling, the
solution is seeded with crystalline lactulose. Crystallization takes
place in the course of several hours, during which time the mixture is
preferably kept in gentle motion. The crystals are collected on a filter
and washed with methyl alcohol. About 75 g of crystalline lactulose is
obtained in the first crop. The rest of the sugar is reclaimed by con-
centrating the mother liquor.
Pure lactulose melts at 160° C and in 4-percent aqueous solution
gives [o]}=–11.9° initially, changing in several hours to -50.7° [2].
NOTES
* For the preparation of lactose see page 467.
* In a typical experiment the optical rotatory change as observed in a 2-dm
tube was as follows:
Polarimetry, Saccharimetry, and the Sugars 469
Time Observed rotation
Hours oS
() 53. 0
25 31. 0
71 30. 1
3 If the titration requires less than 4 ml of the thiosulfate, sufficient iodine and
sodium hydroxide were not added and the analysis must be repeated, using more
of the reagents.
* For each equivalent, use 26 ml of bromine.
* In large-scale preparations Oxalic acid and lead carbonate can be used in place
of silver sulfate. The amount of oxalic acid equivalent to the bromine used is
added first and then an equivalent quantity of lead carbonate. The resulting
insoluble salts are separated and any bromide which remains in the filtrate is
removed by precipitation with silver sulfate, after which the procedure is the same
as that given above.
REFERENCES
[1] E. M. Montgomery and C. S. Hudson, J. Am. Chem. Soc. 52, 2101 (1930).
[2] H. S. Isbell and W. W. Pigman, J. Research NBS 20, 773 (1938) RP1104.
12. d-LYXOSE
Method."—[1] A mixture of 225 g of calcium galactonate.5H2O",
20 g of barium acetate monohydrate, and 10 g of ferric sulfate (crys-
talline) is added to 3 liters of boiling water. After the mixture is
cooled to 35° C, 120 ml of 30-percent hydrogen peroxide * is added.
A vigorous reaction begins in a few minutes. The solution is cooled
so that the temperature does not exceed 50° C. When the solution
turns dark brown, it is cooled to 40°C and a second 120-ml portion of
hydrogen peroxide is added. After the ensuing reaction is complete, .
about 20 g each of a decolorizing carbon and of calcium carbonate are
added and the solution is filtered. The filtrate is concentrated in
vacuo to a sirup of about 80 percent of total solids (n?= 1.490). The
sirup is mixed with 300 ml of methyl alcohol and then with 600 ml of
hot ethyl alcohol. The resulting precipitate is separated by filtration
and washed, first on the filter with 100 ml of ethyl alcohol; then it is
transferred to a beaker and mixed with 200 ml of ethyl alcohol, after
which it is returned to the filter and finally washed with another 100
ml of alcohol. The insoluble residue is discarded. The filtrate is
evaporated in vacuo to a thick sirup (m?=1.51, or about 90 percent of
total solids), which is extracted with 200 ml of hot absolute alcohol.
The residue in the distillation flask is extracted with three 200-ml
portions of hot isopropyl alcohol. The residue is discarded. The
alcoholic extracts are combined and allowed to stand at room tem-
perature until the supernatant liquid is clear. The clear liquid is
decanted from the sirupy residue", and after the addition of a few drops
of acetic acid the solution is evaporated in vacuo to a sirup which is
then seeded with 3-d-lyxose and placed in a desiccator over calcium
chloride for crystallization to take place.” After several days the crys-
tals are collected on a filter, washed with absolute alcohol, and dried.
The yield is about 30 g. The mother liquor is concentrated in vacuo,
the sirup is extracted with absolute alcohol, and the solution is
evaporated to give a second crop.
470 Circular of the National Bureau of Standards
Recrystallization.—An aqueous solution containing a few milliliters
of acetic acid and 100 g of crude lyxose is concentrated in vacuo at
40° C to a sirup of 90 percent of total solids. This sirup is mixed
with 200 ml of hot absolute ethyl alcohol and the hot solution is fil-
tered, using about 5 g of a decolorizing carbon. After cooling and
seeding, about 60 g of crystalline lyxose is obtained.
Usually 3-d-lyxose crystallizes more readily than o-d-lyxose, al-
though either isomer may be obtained by the same procedure.
In 4-percent aqueous solution 3-d-lyxose gives [o]}= -72.6°
initially, changing in 1 or 2 hours to — 13.8°.
|NOTES
1 The method described is a considerable improvement over that Originally
described by Ruff and Ollendorf [2]. The sugar may also be prepared from
d-xylose by application of the glycal method [3] or by the pyridine rearrangement
from d-xylonic acid [4].
* The method used for the preparation of calcium galactonate is similar to
that given on page 524.
* If the hydrogen peroxide is not fresh, it should be analyzed and the volume
equivalent to that given should be used.
* When considerable residue is obtained at this point, it should be extracted
with absolute ethyl or isopropyl alcohol in order to recover the lyxose which is
present.
* In order to obtain a satisfactory crystallization it is necessary to keep the
amount of water in the sirup as low as possible. If the product fails to crystallize,
usually crystallization can be effected by evaporating the alcoholic solution a
second time, dissolving the residue in absolute alcohol, and precipitating the
impurities with isopropyl alcohol.
REFERENCES
[1] R. C. Hockett and C. S. Hudson, J. Am. Chem. Soc. 56, 1632 (1934).
[2] O. Ruff and G. Ollendorff, Ber. deut. chem. Ges. 32, 550 (1899); 33, 1798
(1900).
[3] H. Gehrke and F. Obst, Ber. deut. chem. Ges. 64, 1724 (1931).
[4] E. Fischer and O. Bromberg, Ber. deut. chem. Ges. 29, 581 (1896).
13. MALTOSE (4-(o-d-GLUCOPYRANOSIDO)-d-GLUCOSE)
The technical grade of maltose usually contains considerable quan-
tities of dextrins, which must be removed by precipitation with alco-
hol in order that a pure product be obtained on recrystallization. If
the technical maltose is not available, the following directions, which
are essentially those given by Harding [1] and based on the method of
Herzfeld [2], may be used to prepare maltose from starch.
Method.—Twenty-five hundred grams of soluble starch' is added
to 20 liters of hot water and the mixture is stirred until complete solu-
tion has taken place. After the solution is cooled below 50°C, 100 g of
barley flour (or coarsely ground barley meal) is added and the solu-
tion allowed to stand for 20 hours. The unfiltered solution is then
concentrated under reduced pressure to a volume of about 3 liters.
This solution (or one prepared by dissolving 2,500 g of technical
maltose in water and evaporating the solution to a volume of 3 liters)
is mixed with 5.5 liters of alcohol and stirred for 9% hour with a mechan-
ical stirrer. The insoluble material is allowed to settle and the alco-
holic solution decanted. The gummy residue is mixed with 3 liters
of alcohol. The mixture is allowed to settle, and the alcoholic solu-
tion is separated by decantation. The residue is given a third extrac-
tion with 2 liters of alcohol, the alcohol is separated, and the residue
discarded.
Polarimetry, Saccharimetry, and the Sugars 471
The combined alcoholic extracts are evaporated under reduced pres-
sure to a volume of about 5 liters. The solution is treated with a
decolorizing carbon, filtered, and the filtrate is then evaporated to a
thick sirup (volume less than 1 liter). This is diluted with ethyl alco-
hol (containing 1 percent of nitric acid” by volume) until an amorph-
Ous gum appears. Seed crystals are then added and the solution is
placed in a refrigerator for a day while crystallization takes place.
The solution is diluted with alcohol (containing nitric acid) from time
to time to prevent solidification. The crystals are separated by fil-
tration and washed with alcohol. From the mother liquors, additional
material may be obtained. -
Recrystallization.—The maltose may be recrystallized by dissolving
the crystals in hot water, evaporating the solution in vacuo to a thin
sirup which is taken up with ethyl alcohol, and allowing the sugar to
crystallize, preferably in a slowly rotating flask. The sugar is obtained
as 3-maltose.H2O, which has an initial rotation in 4-percent aqueous
solution of [o]}=-|-111.7° and an equilibrium rotation of +130.4°.
NOTES
* Technical maltose may be purchased for about 50 cents a pound. Soluble
Starch may be prepared by mixing a good grade of commercial starch with suffi-
cient 7.5-percent hydrochloric acid to cover the starch. After the mixture stands
for about 1 week at room temperature, the acid is washed out and the resulting
soluble starch is air-dried.
* The nitric acid assists in removing colored and opalescent material from the
solutions.
REFERENCES
Harding, Sugar 25, 350 (1923).
[1] T. S.
A. Herzfeld, Liebigs Ann. Chem. 220, 209 (1883).
[2]
14. d-MANNOSE
Method.”—[1, 2, 3] One kilogram of screened ivory-nut shavings is
mixed with 1 kg of cold 75-percent sulfuric acid (430 ml of concentrated
sulfuric acid and 250 ml of water). The material is triturated until
the sulfuric acid is uniformly distributed, and is allowed to stand until
the next day, preferably at about 35° C. The mass is then dissolved
in 10 liters of water and the solution is filtered through cheesecloth.
The filtrate is heated to boiling for 6 hours while the volume is main-
tained approximately constant. The hot liquid is then neutralized
with barium carbonate, and after the addition of 200 g of decolorizing
carbon the barium sulfate is separated by filtration. The filtrate is
evaporated in vacuo to a sirup of about 85 percent of total solids
(nà"= 1.503). This sirup is thoroughly mixed with 1 liter of warm
methyl alcohol, after which the solution is diluted with 2 liters of
isopropyl alcohol. This results in the precipitation of some gummy
amorphous material, which is separated by decantation. The larger
part of the mannose is in the alcoholic extract; that in the gummy
residue is separated by triturating the gum with 250 ml of methyl
alcohol and then adding 500 ml of isopropyl alcohol. The mixture
is allowed to settle and the insoluble residue is separated from the
alcoholic extract. The residue thus obtained is given a second treat-
ment with methyl and isopropyl alcohols, and the alcoholic extracts
are combined. After the addition of about 50 g of decolorizing carbon,
the solution is filtered and evaporated in vacuo to a sirup of about
472 Circular of the National Bureau of Standards
60 percent of total solids (nà"= 1.442). This sirup is taken up with
250 ml of glacial acetic acid and seeded with o-d-mannose. In the
course of several days at room temperature, 200 g of crystalline man-
nose separates.” This is collected on a filter and washed with a mixture
containing 3 parts of ethyl alcohol and 1 part of methyl alcohol. A
second crop of 150 g of crystalline mannose is obtained by evaporating
the mother liquors to a thick sirup containing about 85 percent of
total solids (nà"= 1.503). This sirup is taken up in glacial acetic
acid, seeded with o-d-mannose, and allowed to stand in the refrigerator
for several days, after which the crystals are separated in the usual
IY) 8,I\}) {}I’.
Recrystallization.—One hundred grams of crude mannose is dissolved
in 100 ml of water. After the addition of a few drops of acetic acid
and 5 g of a decolorizing carbon, the solution is filtered and evaporated
in vacuo to a heavy sirup (n;"=1.511). The sirup is mixed with 50
ml of warm methyl alcohol, followed by 200 ml. of a mixture contain-
ing equal volumes of methyl and isopropyl alcohols. The sirup is
decanted from any gummy material, filtered if necessary, and then
seeded with about 0.5 g of o-d-mannose and allowed to crystallize,
preferably while kept in motion. In the course of 1 or more days about
75 g of the crystalline sugar separates. By concentrating the mother
liquor and repeating the process, nearly all the mannose can be
separated in the crystalline state.
In 4-percent aqueous solution o-d-mannose gives [o];"= +29.3°
initially, changing in the course of several hours to an equilibrium
value of +14.2°.
NOTES
| The method is similar to that described by Clark [1] but differs in that any
gums are precipitated with a mixture of methyl and isopropyl alcohol. This step
(introduced by Isbell) results in a product which crystallizes readily. Hudson
and Jackson recommend the intermediate preparation of o-methyl mannoside [3].
* The ivory-nut shavings may be purchased from the Button Machinery Co.,
11th, Grand and Adams Sts., Hoboken, N. J.
* If the hydrolysis is incomplete or if the gummy material is not separated, the
mannose may crystallize very slowly.
REFERENCES
[1] E. P. Clark, J. Biol. Chem. 51, 1 (1922).
[2] H. S. Isbell, J. Research NBS 26, 47 (1941) RP1357.
[3] C. S. Hudson and E. L. Jackson, J. Am. Chem. Soc. 56, 958 (1934).
15. MELEZITOSE (d-GLUCOSIDO-SUCROSE)
Occurrence.—The trisaccharide, melezitose, occurs in a manna that
forms upon the Douglas fir, jack pine (Pinus Virginiana Mill), and
other trees as the result of the activities of a reddish-brown soft-scale
insect. During periods of drought, bees collect the manna or honey
dew in sufficient quantity to change the character of the honey,
making it unsuitable for maintaining the bees but providing a source
of melezitose " [1]. Melezitose is not fermented by baker's yeast
and does not reduce Fehling solution. The analysis of melezitose-
containing honey shows a large increase in reducing sugars by acid
inversion in comparison with the increase in reducing sugars by in-
vertase hydrolysis.
Method.”—The honey containing crystalline melezitose is cut into
pieces and coarsely ground in a meat grinder. One liter of ethyl
Polarimetry, Saccharimetry, and the Sugars 473
alcohol is added to each 15 pounds of honey and the mixture is allowed
to stand overnight, after which the solid material is separated on a
basket centrifuge and the cake is washed with 80-percent alcohol. On
account of the difference in the density of the wax and sugar, the
sugar collects as a layer on the outer edge of the basket. The wax
and lighter impurities collect as an inner layer. The sugar and wax
layers are separated mechanically. The outer layer, which is largely
sugar, is mixed with 80-percent aqueous alcohol to form a thin paste
which is passed through a coarse sieve (14 mesh), whereupon the
larger wax particles are retained on the screen while the grains of
sugar pass through. The sugar in the alcoholic suspension is separated
on a centrifuge. The cake is dissolved in hot water and clarified with
a decolorizing carbon. The resulting solution usually contains col-
loidal material, which is removed by adding a small quantity of milk
of lime followed by an equivalent quantity of phosphoric acid. The
cold neutral solution is filtered and evaporated in vacuo. As the
evaporation proceeds, crystalline melezitose forms. When sufficient
crystals are present, the evaporation is stopped and the crystals are
separated. The mother liquors yield additional crystalline sugar by
further evaporation. A small quantity of melezitose can be extracted
from the wax by solution in cold water and subsequent crystalliza-
tion. The yield varies widely with different samples of honey.” In
4-percent aqueous solution melezitose gives [o]}= +88.2°.
NOTES
1 A sample of wax and crystals collected from in front of a hive of bees was
submitted by the Bureau of Entomology, U. S. Department of Agriculture, to
the National Bureau of Standards for analysis. The analysis showed that the
sample contained over 60 percent of melezitose.
* This method was worked out by Hudson and Isbell at the National Bureau
of Standards but has not heretofore been published.
8 From 250 kg of melezitose honey, Isbell and Hudson, working in the Polarim-
etry Section of the National Bureau of Standards, obtained 13 kg of crystalline
melezitose.
REFERENCES
[1] C. S. Hudson and S. F. Sherwood, J. Am. Chem. Soc. 42, 116 (1920).
16. MELIBIOSE (6-(o-d-GALACTOPYRANOSIDO)-d-GLUCOSE)
Method."—[1] Two hundred and fifty grams of raffinose * is dissolved
in 2% liters of water containing a cake of baker's yeast “ (5 to 10 g),
50 g of calcium carbonate, and 50 ml of nutrient solution.* The fer-
mentation is allowed to take place for 3 or 4 days.” After the addi-
tion of 75 g of a decolorizing carbon, the solution is filtered. The
filtrate is treated with 25 g of basic lead acetate, and the lead is
removed by treating with hydrogen sulfide and filtering off the lead
sulfide. The filtered solution is evaporated to a sirup of approximately
80 percent of total solids (m. 2–1.490), after which the sirup is taken
up in 100 ml of glacial acetic acid and nucleated with melibiose hy-
drate. Crystallization * usually takes place in several days at 0°C.
The crystals are separated and washed, first with acetic acid and then
with 95-percent alcohol. The yield is about 100 g.
Recrystallization.—A solution of 100 g of crude melibiose in 70 ml
of hot water is treated with 2 g of a decolorizing carbon and filtered.
The filtrate is cooled, mixed with 150 ml of glacial acetic acid, and
474 Circular of the National Bureau of Standards
seeded with melibiose hydrate. After standing for several days in the
refrigerator, about 50 g of melibiose hydrate crystallizes from the solu-
tion. The crystals are separated and washed, first with glacial acetic
acid, and then with 95-percent ethyl alcohol. Nearly all the sugar
can be reclaimed by concentrating the mother liquors and crystalliz-
ing from aqueous acetic acid.
The sugar crystallizes in the beta modification containing 2 mole-
cules of water of crystallization. In 4-percent aqueous solution,
6-d-melibiose. 2H2O gives [o]}=-|-111.7° initially, which changes in
the course of several hours to +129.5°.
NOTES:
1 Bau [2] describes a similar method but separates the melibiose as the barium
saccharate. A review of the literature is given by Harding [3].
2 Raffinose may be obtained as described on page 475.
* Brewer’s yeast (bottom yeast) must not be used as it contains an enzyme
which hydrolyzes the melibiose [2].
* A stock nutrient solution of the following composition may be used:

Salt g/liter
NaNO3 ams am me - - - - - - - - - - - - - 100
KH2PO4---- - - - - - - - - - - - - 8. 0
MgSO4.7H2O-- - - - - - - - - - - 6. 6
* In a typical experiment the rotation dropped from +52.85° to +40.1°S. The
reaction should be stopped when a proportionate change has been observed.
6 If crystallization does not take place, it can sometimes be induced by adding
a small quantity of water. However, it is sometimes necessary to purify the
sugar further by converting it to the crystalline acetate, which may be deacetyl-
ated to give a nearly pure product that crystallizes readily. The acetylation and
deacetylation are conducted essentially as described for gentiobiose on page 463.
EEFERENCES
[1] C. S. Hudson and T. S. Harding, J. Am. Chem. Soc. 37,2734 (1915).
[2] A. Bau, Z. Wer. deut. Zucker-Ind. 49, 850 (1899).
[3] T. S. Harding, Sugar 25, 514 (1923).
17. NEOLACTOSE (4-(6-d-GALACTOPYRANOSIDO)-d-ALTROSE)
Method.—[1, 2] Heptaacetylneolactose' is deacetylated by the bar-
ium methylate method of Isbell” as follows: Eighty-four grams of the
8-heptaacetylneolactose is dissolved in 1,500 ml of dry methyl alcohol;
the solution is cooled in an ice bath, after which 75 ml of 0.5 N barium
methylate in dry methyl alcohol is added and the solution is kept in a
cold place (0°C) for 20 hours. The barium is removed with an
equivalent quantity of sulfuric acid or by treatment with carbon
dioxide, and the solution is concentrated in vacuo to a thick sirup,
which is dissolved in about 2 volumes of methyl alcohol and allowed to
stand for several days in a refrigerator. Spontaneous crystallization
usually takes place during this time, but if not, the solution must be
nucleated with crystalline material”. The crystals are separated by
filtration and washed with methyl alcohol. The yield is close to the
theoretical.” The crystals are purified by dissolving them in water,
evaporating the solution under reduced pressure to a thin sirup,
Polarimetry, Saccharimetry, and the Sugars 475
dissolving the sirup in methyl alcohol, and allowing crystallization
to take place, preferably in a slowly rotating flask.
The pure material has a melting point of 190° C and exhibits
a small mutarotation from an initial value of [o]}= +33.8° to an
equilibrium value [a]*}= +35.5°.
NOTES
| Heptaacetylneolactose is prepared from chloro-heptaacetylneolactose (page
502) by the method described for heptaacetyl-4-(6-d-glucosido)-d-mannose on
page 491.
* Additional details for carrying out this method of deacotylation are described
on page 464.
* Seed crystals may be obtained by rubbing up a small quantity of the sirup
with acetone and alcohol.
* In a typical experiment 31 g was obtained from the first crystallization and
the mother liquors yielded 7 g additional.
REFERENCES
[1] N. K. Richtmyer and C. S. Hudson, J. Am. Chem. Soc. 57, 1716 (1935).
[2] A. Kunz and C. S. Hudson, J. Am. Chem. Soc. 48, 1978 (1926).
18. RAFFINOSE (d-GALACTOSIDO-SUCROSE)
Commercial source.—Since the trisaccharide, raffinose, is commer-
cially available at a reasonable price, details of a preparatory method
are not given. The sugar is produced in large quantities as a by-
product of the “Barium Process” for the recovery of sucrose from beet
molasses and may be obtained from The Great Western Sugar Co.,
Denver, Colo. Methods for the preparation of raffinose are given
in references [1, 2, 3]. 3.
Recrystallization.—Three hundred grams of raffinose is dissolved
with 200 ml of water. After the addition of a small quantity (5 g)
of a decolorizing carbon, the hot solution is filtered and the residue
on the filter is washed with 25 ml of hot water. The filtered solution
is mixed with 200 ml of ethyl alcohol and seeded with crystalline
raffinose. The mixture is allowed to cool slowly while being stirred.
After several hours the resulting crystals are separated by filtration
and are washed, first with a mixture of equal volumes of water and
ethyl alcohol, and then with 95-percent ethyl alcohol. The first crop
of crystals constitutes about 75 percent of the total sugar. The
sugar in the mother liquor is reclaimed by evaporating the solution
in vacuo. In 10-percent aqueous solution raffinose pentahydrate gives
[o]}= + 105.2°. It does not exhibit mutarotation.
REFERENCES
[1] E. P. Clark, BS Sci. Pap. 17, 607 (1922) S432; J. Am. Chem Soc. 44, 210 (1922).
[2] T. S. Harding, Sugar 25, 308 (1923).
[3] E. H. Hungerford and A. R. Nees, Ind. Eng. Chem. 26, 462 (1934).
19. l-RHAMNOSE (l-MANNOMETHYLOSE)
Method.—[1, 2] Five hundred grams of lemon flavine is boiled with
4 liters of 0.5-percent (by weight) sulfuric acid for 5 hours,” after
which the hot solution is then filtered through a large Büchner funnel.
The acid in the hot filtrate is neutralized by the cautious addition of
barium carbonate. The precipitate of barium sulfate is removed by
filtration and the filtrate is then treated with 400 g of a decolorizing
476 Circular of the National Bureau of Standards
carbon, allowed to stand overnight, filtered, and evaporated to a
75-percent sirup (nº=1.477) which crystallizes readily.” The crystals
are separated and washed, first with 1:1 aqueous ethyl alcohol and
then with 95-percent ethyl alcohol. The yield is about 90g. A review
of the literature is given by Harding [3].
Recrystallization.—Three parts of rhamnose hydrate are dissolved
with 2 parts of hot water. After a small quantity of a decolorizing
carbon is added, the solution is filtered and seeded with crystalline
rhamnose. Crystallization takes place in the course of several hours
at room temperature, during which time the mixture is preferably
kept in motion. The crystals are separated and washed, first with
75-percent and then with 95-percent aqueous alcohol. The first crop
of crystals is about 60 percent of the crude product. By concen-
trating the mother liquors in vacuo, additional crystalline sugar is
obtained.
The modification of the sugar obtained under these conditions is
o'-l-rhamnose monohydrate. In 4-percent aqueous solution this sub-
stance exhibits [o]*= —8.6° and at equilibrium +8.2°.
|NOTES
1 Lemon flavine is a commercial yellow dyestuff prepared from black oak bark
and may be obtained from J. S. Young and Company, Hanover, Pa.
* The solution may be heated over a direct flame, provided a suitable stirring
device is used. Foaming may be reduced by the Occasional addition of an antifoam
agent, such as capryl alcohol.
* If crystallization does not take place spontaneously, add seed crystals. If
crystallization still does not commence, extract the aqueous solution with 95-
percent alcohol, discard the residue, and evaporate the extractions to a sirup of
about 75 percent of total solids, seed, and allow to stand until crystallization takes
place.
REFERENCES
[1] C. Liebermann and O. Hörmann, Liebigs Ann. Chem. 196, 323 (1879).
[2] C. F. Walton, Jr., J. Am. Chem. Soc. 43, 127 (1921).
[3] T. S. Harding, Sugar 25, 82 (1923).
20. d-RIBOSE
Method.—[1, 2, 3,4] The following specific directions for the prepara-
tion of ribose have been found convenient and effective in this labor-
atory.
Hydrolysis of nucleic acid.—Five hundred grams of commercial yeast
nucleic acid," 100 g of magnesium oxide, and 3 liters of distilled water
are placed in a 4-liter Pyrex beaker and mixed until a uniform, smooth
suspension is obtained free from lumps.” The mixture in the 4-liter
beaker or in a 5-liter short-necked flask * is placed in an autoclave
and heated to 145° C (60 pounds steam pressure) for 4 hours with
continuous stirring.” The maximum working range of temperature
lies between approximately 120° and 155° C [5].
The pressure in the autoclave is then réduced as quickly as possible
without causing the reaction mixture to boil over. As soon as the
pressure is reduced, the autoclave is opened and the boiling-hot reac-
tion mixture filtered through a little decolorizing carbon on a large
Büchner funnel into a 4-liter filtering flask.” The copious precipitate
of magnesium-containing phosphates is packed down and washed
with 1 to 1% liters of boiling water, making the total volume of filtrate
and washings between 3.5 and 4 liters.
Polarimetry, Saccharimetry, and the Sugars 477
Separation of guanosine.—The filtrate from the hydrolysis of
nucleic acid is allowed to stand overnight in a stoppered 4-liter
Erlenmeyer flask at room temperature, or preferably in the icebox
to permit the guanosine to crystallize out as completely as possible.
The crude guanosine is filtered off and washed on the filter with
cold water followed by alcohol to facilitate drying. The yield is 70
to 80 g of crude air-dried guanosine.
Purification of guanosine.—The crude guanosine is purified by re-
crystallization from a 4-percent solution in water. Two and one-half
liters of distilled water is heated to boiling and to this is added 100 g
of crude guanosine. The mixture is stirred vigorously to hasten solu-
tion and when dissolved it is filtered immediately " through a little
decolorizing carbon " on a large Büchner funnel. The filtrate is cooled
and allowed to stand overnight, whereupon crystalline guanosine
separates. The product is collected on a filter, washed with water
and then with alcohol, and dried at a low temperature (about 35° C).
Usually one recrystallization provides sufficient purification. How-
ever, if the crystals in the magma do not show clean-cut end faces, or
if the magma appears somewhat gelatinous, a second recrystallization
after filtration through carbon may be desirable.
Separation of adenosine.—From the filtrate obtained from the crude
guanosine, adenosine may be precipitated without further purification
by the addition of picric acid, or if desired, a preliminary treatment
may be given to remove the small excess of magnesia as follows:
To the filtrate obtained from the crude guanosine is added a solution
of about 2 g of ammonium phosphate, followed by dilute barium
hydroxide to about pH 9, or as long as a precipitate continues to be
formed. The solution is filtered. The filtrate is immediately treated
with dilute sulfuric acid in sufficient quantity to precipitate any barium
salts, which are then separated by filtration. The addition of dilute
sulfuric acid to the filtrate is continued until the solution remains just
acid to congo red. At this point a nearly saturated solution of picric
acid in hot 90-percent alcohol is added until no more immediate pre-
cipitate is formed. Approximately 50 g of picric acid is required.
The precipitate is filtered, washed with water slightly acidified with
picric acid, then with alcohol, and finally is air-dried. About 100
to 115 g of air-dried crude adenosine picrate containing some cytidine
picrate is obtained.
Purification of adenosine picrate.—The crude adenosine picrate may
be sufficiently purified by one or two recrystallizations from hot water
using a little decolorizing carbon in the filtration. The crude wet
adenosine picrate is taken from the filter, and without drying, is added
immediately to boiling water " until the solution is nearly saturated,
whereupon it is filtered at once through washed carbon 7 on a large
Büchner funnel. The solution is allowed to crystallize overnight, and
the crystals are filtered, washed with water and alcohol, and air-dried.
Adenosine picrate may be hydrolyzed directly without removing the
picric acid.
Hydrolysis of guanosine.—One hundred grams of recrystallized
guanosine is dissolved in 10 liters of approximately 0.1 N sulfuric acid
at the boiling temperature, and hydrolysis at boiling temperature is
allowed to proceed for 1 hour,” after which the solution is treated with
an excess of silver sulfate dissolved or suspended in hot water. The
323.414 °. 42 32
478 Circular of the National Bureau of Standards
solution is allowed to cool and stand overnight at room temperature
(or preferably in the icebox at as low a temperature as is practicable),
and the insoluble guanidine-silver sulfate compound is separated by
filtration.
The filtrate is neutralized with barium hydroxide to a pH of about
6.4 to 7.0, in two stages; the bulk of the barium sulfate is filtered off
while the solution is decidedly acid, since the barium sulfate will be
found to filter much more readily in acid than in neutral solution.
The neutralization of the small remaining amount of acid is completed
to a pH of 6.4 to 7.0, using brom thymol blue, a glass electrode, or
Some other convenient pH indicator. The solution is filtered through
a Büchner funnel, using enough decolorizing carbon to prevent the
clogging of the filter by the barium sulfate. The neutral filtrate is
concentrated under reduced pressure at a low temperature to a thick
sirup, which is taken up with about 500 ml of warm absolute alcohol.
A small quantity of decolorizing carbon is added and the solution
filtered. The filtered solution is evaporated again in vacuo to a thick
sirup, which is diluted with a little warm absolute alcohol and seeded
with d-ribose. Crystallization usually starts within a few minutes and
is completed overnight. The crystals are collected on a filter, washed
with alcohol, and dried.
Ribose may be purified by dissolving in a very small amount of
water, adding alcohol, filtering through carbon, and allowing to stand
until crystallization is complete, preferably in the icebox.
The mother liquors, both from the crude and from the recrystallized
ribose, may be retreated to yield further crops of crystals.
Hydrolysis of adenosine picrate.—One hundred and fifty grams of
recrystallized adenosine picrate is dissolved in 10 liters of boiling water.
When solution is complete, 70g of sulfuric acid is added and hydrolysis
is allowed to proceed for 1 hour at 100° C. The solution is allowed to
stand overnight at room temperature, or preferably in the refrigerator,
in order that the insoluble adenine picrate may completely crystallize.
After separation of the adenine picrate by filtration, the sulfuric acid
in the filtrate is neutralized in two steps, as described for guanosine,
and the filtrations in each case are made through a matt of decoloriz-
ing carbon on a large Büchner funnel. From this point on, the pro-
cedure is identical with that described above for guanosine.
The yield from 500 g of nucleic acid assaying 83 percent has been
found to be about 35 g of ribose from the guanosine and 25 g from the
adenosine picrate, or a total of 60 g of crystalline d-ribose.
NOTES
* Nucleic acid purchased from several chemical firms has been found satisfactory.
* If preferred, the nucleic acid may first be dissolved in water containing a little
ammonia and the magnesia, then added, although this procedure is not necessary.
* The sizes of vessels and the quantities of materials specified are based in part
upon the capacity of the autoclave available. If the reaction is conducted in a
flask, more vigorous stirring may be used without splashing.
* The yield is materially reduced if stirring is not used. This probably results
from the formation of relatively insoluble magnesium nucleotides which, if not
kept in suspension by stirring, cake upon the bottom and cause the hydrolysis to
proceed less smoothly.
* At this stage the reaction of the filtrate should preferably be slightly alkaline,
about pH 7.5 to 8.0. An acid reaction indicates that insufficient magnesia was
used. It is important that the solution not be allowed to become acid during the
hydrolysis, because at the high temperature employed there would be danger of
hydrolyzing some of the riboside and so losing ribose in the reaction mixture.
Polarimetry, Saccharimetry, and the Sugars 479
* Avoid heating longer than is necessary as the guanosine is easily hydrolyzed.
The same is true of adenosine.
* The decolorizing carbon should be thoroughly washed with hot water.
* To avoid bumping, a drying oven which will accomodate a 12-liter flask is
excellent for carrying out the hydrolysis, both of guanosine and of adenosine picrate.
REFERENCES
. P. Phelps, U. S. Patent 2,152,662.
. P. Phelps and F. J. Bates, Publication pending.
. A. Levene and E. P. Clark, J. Biol. Chem. 46, 19 (1921).
. Bredereck, Ber. deut. chem. Ges. 71, 408 (1938).
. Jones and H. C. Germann, J. Biol. Chem. 25, 93 (1916).
21. l-SORBOSE
Biological source.—The biological synthesis of l-sorbose from d-sor-
bitol by bacterial fermentation has been developed by the Indus-
trial Farm Products Research Division of the Bureau of Agricultural
Chemistry and Engineering, and yields of more than 90 percent are
obtained [1].
Crystallization.—Three parts of sorbose are dissolved with 2 parts
of water containing a few drops of acetic acid. After the addition of a
small quantity of a decolorizing carbon the hot solution is filtered.
The clear filtrate is allowed to cool slowly while it is stirred. Crystal-
lization takes place as the solution cools. After standing for several
hours at room temperature or below, the crystals are separated and
washed, first with a mixture of methyl alcohol (2 volumes) and water
(1 volume) and then with undiluted methyl alcohol. About 50 per-
cent of the crude sugar separates in the first crop of crystals. By
evaporating the mother liquor in vacuo to a sirup of about 70 percent
of total solids, additional sorbose crystallizes. In 11-percent aqueous
solution, l-Sorbose gives [o]}=–43.7° initially, changing in several
hours to —43.4.”
REFERENCES
[1] P. A. Wells, J. J. Stubbs, L. B. Lockwood, and E. I. Roe, Ind. Eng. Chem.
29, 1385 (1937).
22. d-TALOSE
Method.—[1, 2, 3] d-Talose may be prepared from galactose
through the intermediate preparation of pentaacetylgalactose (see
page 488), 1-bromoacetylgalactose (see page 500), triacetylgalactal
(see page 532), and galactal. An aqueous solution of galactal
(150 g in 1,500 ml of water) is cooled to 0°C and treated with a solu-
tion of 174 g of perbenzoic acid in 1 liter of ether." The mixture is
stirred at 0°C for 4 hours and for several additional hours while the
temperature is allowed to rise slowly to room temperature. The
aqueous phase is separated and extracted three times with ether and
three times with chloroform. The purified aqueous solution is then
concentrated in vacuo to a thin sirup (about 70 percent) and allowed
to stand overnight. About 5 g of difficulty soluble monobenzoyltalose
crystallizes and is separated by filtration and washed with water.”
The mother liquors are evaporated to a thin sirup which is taken
up with methanol and allowed to crystallize. The crystals are sep-
arated and the mother liquor is again evaporated and crystallization
allowed to take place. This process is repeated until no further
crystallization occurs.” The various crops are then combined and
480 Circular of the National Bureau of Standards
extracted for an hour with eight times their weight of gently boiling
methanol. The undissolved material" is removed by filtration and
the filtrate is evaporated to a thin sirup which crystallizes to give
crude d-talose." The sugar is recrystallized by dissolving it in water
and concentrating the solution to a sirup which is diluted with methyl
alcohol and seeded. Pure d-talose may be obtained by recrystallizing
once more the material obtained. From 150 g of galactal a total of
about 50 g of d-talose may be obtained. This corresponds to a yield
of about 80 g of d-talose from 500 g of galactose. & 2 º'
The form of d-talose obtained under ordinary conditions melts
at 133° to 134°C and in 4-percent aqueous solution exhibits a rapid
complex mutarotation from an initial value of [o]}= +68.0° to an
equilibrium value of [o]}=+20.8°. º . re
The pyridine rearrangement of galactonic acid and the reduction
of the talonic acid formed has also been used for the preparation of
talose [4, 5).
NOTES
| Preparation of perbenzoic acid.—Thirty grams of finely ground sodium peroxide
is added with vigorous stirring to 400 ml of ice and water and after the addition
of 200 ml of cold ethyl alcohol (– 5°C), 25 ml of benzoyl chloride dissolved in
100 ml of cold ether is added. The mixture is stirred for several minutes and is
then filtered through a large Büchner funnel. The filtrate, after acidification
with 700 ml of cold (0°C) normal sulfuric acid, is extracted with four 150-ml
portions of ether. The solution should be kept as cold as possible until the final
acidification; about 20 g of perbenzoic acid is obtained.
* Alcohol should not be used for washing this product.
* Additional material may be obtained from the mother liquor by heating it
near the boiling point with 0.05 N sulfuric acid for several hours. The cold
solution is extracted with ether, neutralized with barium carbonate, filtered,
and evaporated as before. This treatment hydrolyzes the benzoyl derivatives
of galactose and talose which may be present.
* Usually this material is nearly pure galactose with an optical rotation be-
tween [o]}= +76° and +80°. If the rotation is below this, another extraction
is advantageous.
* The optical rotation of this material is between [o]}= +25° and + 30°.
REFERENCES
W. W. Pigman and H. S. Isbell, J. Research NBS 19, 189 (1937) RP1021.
P. A. Levene and R. S. Tipson, J. Biol. Chem. 93, 631 (1931).
M. Bergmann and H. Schotte, Ber. deut. chem. Ges. 54, 440 (1921).
W. Bosshard, Helv. Chim. Acta 18, 482 (1935).
5] C. Glatthaar and T. Reichstein, Helv. Chim. Acta 21, 3 (1938)
23. TURANOSE (3-(o-d-GLUCOPYRANOSIDO)-d-FRUCTOSE) 1
Method.—[1, 2, 3] One hundred grams of pure melezitose *is dissolved
in 1 liter of boiling water containing 4 ml of concentrated sulfuric acid.
The solution is boiled gently for 15 minutes and is then neutralized
with an excess (10 g) of calcium carbonate and cooled to 37° C. A
cake of compressed baker’s yeast and 20 ml of nutrient solution * are
added, and fermentation is allowed to take place at 37° C for about
4 days, after which about 10 g of a decolorizing carbon is added and
the solution is filtered. The filtrate is evaporated in vacuo to a sirup
of about 88 percent of total solids (m?=1.511). The sirup is taken
up with 150 ml of methyl alcohol, and after the addition of 5 g of a
decolorizing carbon the solution is filtered. The filtrate is seeded
with crystals of turanose * and allowed to stand. After several days
the crystals are separated and the mother liquor is concentrated again
Polarimetry, Saccharimetry, and the Sugars 481
to give additional product. The total yield from 100 g of melezitose
is about 50 g.
Recrystallization.—One hundred grams of turanose is dissolved in
100 ml of hot water. After adding 5 g of a decolorizing carbon, the
solution is filtered and then evaporated in vacuo to a sirup (n?= 1.490)
containing about 80 percent of total solids. This sirup is dissolved in
100 ml of hot methyl alcohol. After the addition of 5 g of a decolor-
izing carbon, the hot solution is filtered. The filtrate, after cooling
to room temperature, is seeded and preferably stirred while crystalliza-
tion takes place. After several hours the crystals are collected on a
filter and washed with methyl alcohol. The yield is about 75 g. The
remaining sugar is reclaimed by concentrating the mother liquor,
adding methyl alcohol, and separating the crystals which form.
In 4-percent aqueous solution, turanose gives [o]}= +27.3° initially,
changing in the course of an hour to an equilibrium value of +75.8°.
NOTES
| The 3-glucosidofructose structure for turanose was first proposed by Isbell
and Pigman [4].
* The method for obtaining melezitose is described on page 472.
* The nutrient solution is prepared by dissolving 2.5 g of NH4NO3, 0.3 g of
KH2PO4, and 0.25 g of MgSO4.7H2O in 100 ml of water.
* The seed crystals originally used at this Bureau were part of the product first
discovered by D. H. Brauns.
REFERENCES
| C. S. Hudson and E. Pacsu, J. Am. Chem. Soc. 52, 2522 (1930).
] G. Tanret, Compt. rend. 142, 1424 (1906).
| M. Bridel and T. Aagaard, Bul. soc. chim. biol. 9, 884 (1927).
] H. S. Isbell and W. W. Pigman, J. Research NBS 20, 787 (1938) RP1104.
24. d-XYLOSE
Method."—[1] One kilogram of shredded or broken corn cobs is
boiled * for 3 hours with 6 liters of 7-percent sulfuric acid, after which
the insoluble residue is separated on a filter and washed with water,
The aqueous solution is neutralized with calcium carbonate, and after
removal of the insoluble calcium sulfate, the liquor is treated with
baker's yeast. When the ensuing fermentation is complete, about
100 g of decolorizing carbon is added and the solution is filtered.”
The filtrate is concentrated in vacuo to a sirup (m?=1.442, 60 percent
of total solids), which is then diluted with 3 volumes of methyl alcohol.
After separation of the resulting precipitate, the alcoholic solution is
evaporated in vacuo to a sirup (85 percent of total solids, n}=1.503),
which is mixed with 250 ml of methyl alcohol and seeded with crystal-
line d-xylose. After standing for several days, the crystalline product
is separated and washed with 75 percent by volume of aqueous methyl
alcohol. The yield is about 12 percent.”
Recrystallization.—One kilogram of xylose is dissolved with 400 ml
of water containing a few drops of acetic acid. After the addition of
15 g of a decolorizing carbon, the hot solution is filtered and the filtrate
is cooled and kept in gentle motion for several hours while crystalliza-
tion takes place. The crystals which form are separated and washed
with water or with aqueous alcohol. The yield is about 50 percent
in the first crop. The sugar in the mother liquor crystallizes readily
from sirups of about 75 percent of total solids.
482 Circular of the National Bureau of Standards
o-d-Xylose melts at 145° C and in 4-percent solution gives
[o]}=-|-93.6° initially, changing in several hours to +18.8°.
NOTES
* The commercial production of xylose from cottonseed hulls is described by
Schreiber, Geib, Wingfield, and Acree [2].
* The hydrolysis can be conducted in an Inchronel metal pot.
* In the event that the solution at this point is dark colored, it should be clarified
further by treatment with basic lead acetate followed by hydrogen sulfide [3].
* By using the basic lead acetate clarification mentioned in note 3, the method
can be used for the preparation of xylose from cottonseed hulls.
REFERENCES
[1] C. S. Hudson and T. S. Harding, J. Am. Chem. Soc. 40, 1601 (1918).
[2] W. T. Schreiber, N. W. Geib, B. Wingfield, and S. F. Acree, Ind. Eng. Chem. 22.
497 (1930).
[3] H. S. Isbell, J. Research NBS 13, 515 (1934) RP723.
XXXI. METHODS FOR THE PREPARATION OF CERTAIN
SUGAR DERIVATIVES
In this chapter characteristic methods for the production of acetal
and ketal derivatives, esters, ethers, glycosides, mercaptals, and
oxidation and reduction products are given. A résumé of the
characteristic properties of each group is followed by typical direc-
tions for the synthesis of specific compounds and a list of pertinent
references. The methods are selected from those found in the
literature as being of general use. No attempt has been made to
give a complete bibliography or to report original work. Many of
the original methods have been modified and improved in various
ways. The physical constants of the products are selected from data
in the literature and are not always to be found in the articles describ-
ing the method. Additional literature references are cited in the
table of sugar derivatives (p. 704). Whenever possible the examples
were chosen from the work of the members of this Bureau's staff.
For this reason a general method applicable to any sugar may have
been illustrated by a specific example for a rare and relatively
inaccessible sugar.
1. ACETAL AND KETAL DERIVATIVES
General characteristics of the acetal and ketal derivatives.—The sugars
and many of their derivatives condense with aldehydes and ketones
to give compounds which are useful for the preparation of partially
substituted sugars, and for the preparation and purification of
derivatives and products of diverse types.
The configurational relationships of the hydroxyls determine in
large measure whether or not a condensation will take place. The
effect of configuration in relation to the particular ketone or aldehyde
used has been reviewed [1, 2].
The condensation of acetone with a sugar is carried out by mixing
the sugar with acetone and a dehydrating agent. Some of the de-
hydrating agents which have been used are hydrogen chloride [3],
anhydrous copper sulfate [4], sulfuric acid [5, 6], zinc chloride [7], and
phosphorus pentoxide [8]. The use of anhydrous copper sulfate
rather than an acid is often desirable when glycosides are condensed
Polarimetry, Saccharimetry, and the Sugars 483
with acetone, as otherwise ring shifts and other structural changes
may occur. Most sugars give diacetone derivatives. The monoace-
tone sugars are most easily prepared from the diacetone derivatives
by carefully regulated acid hydrolysis. Usually the acetone groups
are split off at different rates; for example, the acetone group in the
5,6 position of 1,2-5,6-diacetone-d-glucose is hydrolyzed 40 times as
fast as that in the 1,2 position.
Examples of the condensation of sugars with aldehydes are the
benzylidine sugars, which are prepared by the action of benzaldehyde
on the sugars in the presence of a dehydrating agent, such as phos-
phorus pentoxide [9], anhydrous sodium sulfate [9], zinc chloride
[10], or hydrogen chloride [11]. The benzylidine groups are removed
by treatment with acid in water solution or by hydrogenation with a
palladium catalyst in alcoholic solution [12]. The di-o-nitrobenzyli-
dine derivatives of a number of sugars have been prepared and are
interesting in that they resist acylation, and isomerize to 0-nitro-
sobenzoates in the presence of light, sometimes with a simultaneous
Walden inversion [13]. The preparation of 4,6-benzylidine-o-d-
glucose is described later in this section. Condensation products of
sugars and derivatives with acetaldehyde (ethylidine sugars) [14,15],
furfuraldehyde [16], and formaldehyde [17] have also been prepared.
(a) SULFURIC ACID METHOD FOR THE PREPARATION OF ACETONE DERIVATIVES
(1) 1,2-5,6-DIACETONE-d-GLUCOSE.
Method [6].-One hundred grams of anhydrous dextrose is shaken
with 2 liters of dry acetone containing 80 ml of concentrated sulfuric
acid. After 5 hours, when most of the sugar has dissolved, an excess
of anhydrous sodium carbonate is added, the solution is filtered, and
the filtrate is evaporated to a heavy sirup which is taken up with
cold water. A small amount of amorphous material which separates
is discarded. The solution is extracted three times with benzene and
the extracts are washed with water. The combined aqueous solu-
tion and washings of the benzene extracts are treated with a de-
colorizing carbon and are then extracted a number of times with
one-fifth of their volume of chloroform. The chloroform extract,
upon drying and evaporation in vacuo, yields 102 to 106 g of crystalline
diacetoneglucose. The mother liquor, after concentration in vacuo
to a heavy sirup which is taken up with alcohol, gives about 20 g of
monoacetoneglucose.
The pure 1,2-5,6-diacetone-d-glucose melts at 110° to 111° C and
gives [o]?= –18.5° (water, c=5). The 1,2-monoacetone-d-glucose
melts at 161° C and gives [o]}=–11.8° (water, c=8).
(2) 1,2-4,5-DIACETONE-d-FRUCTOSE.
Method [4].-Seventy-five grams of dry powdered levulose is shaken
with 1% liters of acetone and 7% ml of sulfuric acid for 20 hours. The
reaction product is neutralized with ammonia gas, filtered, and con-
centrated in vacuo. The partially crystallized sirup is extracted with
ether. The undissolved sirup is mainly 2,3-monoacetonefructose which
can be extracted by shaking with 100 ml of 5 N sodium hydroxide.
The ether solution containing 1,2-4,5-diacetonefructose is purified by
washing, first with dilute (1: 10) sulfuric acid and then with dilute
sodium hydroxide solution. The ether solution, dried with sodium
sulfate, is evaporated in vacuo and the residue recrystallized from
484 Circular of the National Bureau of Standards
petroleum ether. The yield is 32 g of pure 1,2-4,5-diacetone-d-fructose,
which has a melting point of 118° to 119°C and gives [o]}= – 146.6°
(chloroform, c=2.5) [18]. -
(b) COPPER SULFATE METHOD FOR THE PREPARATION OF ACETONE DERIVATIVES
(1) MonoACETONE AND DIACETONE DERIVATIVEs of METHYL
o-d-MANNOPYRANOSIDE.
Method [19].—Ten grams of methyl o-d-mannopyranoside is shaken
at room temperature with 400 ml of dry acetone for 10 days in the
presence of anhydrous copper sulfate.' The filtered solution is con-
centrated in vacuo to a sirup from which some unchanged methyl
o-d-mannoside is eliminated by taking up the sirup in cold acetone.
The resulting sirup is separated into two fractions by a vacuum
distillation at 0.03 mm pressure.
One fraction (1.6 g), which distills at a bath temperature of 125° to
130°C, crystallizes slowly when kept in a desiccator. This product,
methyl 2, 3–4, 6-diacetone-o-d-mannoside, after recrystallization from
aqueous alcohol, melts at 76° to 77°C and gives [o] }=-|-3° (methyl
alcohol, c=2.4). A second portion (0.8 g) distills at a bath tempera-
ture of 165° to 170° C and crystallizes when seed of methyl 2,3-mono-
acetone-o-d-mannopyranoside is added. This substance melts at
105° C and gives |o]}= +24.3° (water, c=4). [20]
NOTES
1 In order to prevent ring changes during the reaction, it is necessary that the
acetone be free of methyl alcohol. Better yields may be obtained by carrying out
the reaction at 50° C. Certain glycosides, such as methyl 3-d-mannoside, require
a longer reaction time, in some cases several months.
(c) HYDROLYSIS OF THE DIACETONE DERIVATIVE TO GIVE A MONOACETONE
DERIVATIVE
(1) 1,2-MONOACETONE-d-GLUCOSE.
Method [21]..—Fifty grams of 1,2-5,6-diacetone-d-glucose (see
p. 483) is dissolved in 400 ml of ethyl acetate containing 4 ml of
concentrated nitric acid. The solution is heated to boiling and
cooled. The 1,2-monoacetone-d-glucose which separates at once is
purified by recrystallization from water or neutral ethyl acetate.
(d) ZINC CHLORIDE METHOD FOR PREPARING BENZYLIDINE DERIVATIVES
(1) 4,6-BENZYLIDINE-o-d-GLUCOSE.
Method [12].-One hundred and thirty grams of anhydrous dextrose
and 100 g of finely powdered fused zinc chloride are shaken with 300
ml of freshly distilled benzaldehyde for 24 hours on the shaking
machine. The thick liquid is then mixed with 400 ml of ice-cold water,
whereupon crystallization takes place. The mixture is filtered and
the crystals are washed, first with cold water and then with petroleum
ether. Between 60 and 70 g of material is obtained. The crystals
are recrystallized several times from 10 times their weight of hot
water to which enough ammonia is added to make the solution
alkaline. About 20 to 25 g of pure material is obtained which melts
at 188° C. 4,6-Benzylidine-o-d-glucose is dextrorotatory in methyl
alcoholic solution and mutarotates to a value of about –4°.
Polarimetry, Saccharimetry, and the Sugars 485
(e) REFERENCES
[1] W. N. Haworth and E. L. Hirst, Ann. Rev. Biochem. 5, 82 (1936).
[2] E. L. Hirst and S. Peat, Ann. Repts. of Prog. Chem., 32, 278 (1935).
[3] E. Fischer and C. Rund, Ber. deut. chem. Ges. 49, 93 (1916).
[4] H. Ohle and I. Kohler, Ber. deut. chem. Ges. 57, 1566 (1924).
J. Böeseken and P. H. Hermans, Ber. deut. chem. Ges. 55, 3758 (1922).
D. J. Bell, J. Chem. Soc. 1935, 1874.
| H. O. L. Fischer and C. Taube, Ber. deut. chem. Ges. 60, 488 (1927).
8] D. Smith and J. Lindberg, Ber. deut. chem. Ges. 64, 505 (1931).
[9] W. A. Van Ekenstein and J. J. Blanksma, Rec. trav. chim. 25, 153 (1906).
| 10] IV. Freudenberg, H. Toepffer, and C. C. Andersen, Ber. deut. chem. Ges. 61,
1750 (1928).
[11] w A. Van Ekenstein and C. A. Lobry de Bruyn, Rec. trav. chim. 18, 305
1899).
[12] L. Zervas, Ber. deut. chem. Ges. 64, 2289 (1931).
[13] I. Tanasescu and E. Craciunescu, Bul. soc. chim. 3, 581, lo 17 (1936).
[14] B. Helferich and H. Appel, Ber. deut. chem. Ges. 64, 1841 (1931).
[15] H. Appel, J. Chem. Soc. 1935 425.
16] H. Brederick, Ber. deut. chem. Ges. 68, 777 (1935).
[17] º, Lobry de Bruyn and W. A. Van Ekenstein, Rec. trav. chim. 22, 159
1903).
[18] D. H. Brauns and H. L. Frush, BS J. Research 6, 454 (1931) RP287.
[19] R. G. Ault, W. N. Haworth, and E. L. Hirst, J. Chem. Soc. 1935, 1012.
[20] R. G. Ault, W. N. Haworth, and E. L. Hirst, J. Chem. Soc. 1935, 517.
[21] º Coles, L. D. Goodhue, and R. M. Hixon, J. Am. Chem. Soc. 51, 523
1929).
º
2. ACETYL DERIVATIVES
General characteristics of the acetylation reactions.—The acetylation
of the nonreducing sugars and other derivatives which consist of a
single modification can be carried out by almost any method which
does not affect the rest of the molecule, but the acetylation of the
reducing sugars is complicated by the existence of several ring
modifications. For this reason it is necessary to select a method
which will give the desired crystalline product. The isomer obtained
depends upon the catalyst used in the acetylation and upon the
temperature. The following general scheme [1] illustrates the effect
of these factors on the acetylation of glucose. At low temperatures
(0°C) the equilibria represented by reactions I and II are only slowly
III
ZnCl2, pyridine
o-d-Glucose → pentaacetyl-o'-d-glucose
I |ac, H2SO4, or HCl II
! | H2SO4, ZnCl2, pyridine (cold)
8-d-Glucose → pentaacetyl-3-d-glucose
sodium ycetate
established and the acetylation reactions III or IV take place without
isomerization. By using pyridine (or zinc chloride) and a low tem-
perature, the alpha aldohexose yields the alpha pentaacetate and the
beta aldohexose yields the beta pentaacetate. At higher temperatures,
in the presence of acid catalysts, isomerization between the acetates
takes place and the products obtained depend upon the position of
the equilibrium represented by the reaction II. For glucose the
equilibrium mixture of pentaacetates consists of 90 percent of the
alpha and 10 percent of the beta pentaacetylglucose [2]. For most
sugars the alpha acetate predominates in the equilibrium mixture
486 Circular of the National Bureau of Standards
and consequently the use of acid catalysts, such as zinc chloride, and
a relatively high temperature (20° to 110° C) gives the alpha acetate
from either the alpha or beta sugar. With sodium acetate as a catalyst
at a high temperature, the equilibrium between the alpha and beta
sugars is established, while the equilibrium between the acetates is
not. Since the beta sugar is acetylated more rapidly than the alpha,
the principal product is then the beta acetyl sugar. The diagram
also illustrates how the alpha acetates may be prepared from the beta
acetates. A mixture of sulfuric acid, acetic acid, and acetic anhydride
has been found to be a very useful isomerization reagent [3]. In
some cases the equilibrium solutions contain appreciable quantities
of the furanose modification, and both pyranose and furanose modifi-
cations are produced. The four cyclic acetates of galactose [4,5] have
been separated. *
Sugar acetates with the acetyl groups of carbons 1 and 2 in th
trans position may be prepared by treating the halogeno-acetyl sugars
with silver acetate. The replacement of the halogen in the halogeno-
acetyl sugars is usually accompanied by Walden inversion, and as
pointed out by Isbell [6], the course of the reaction depends on the
cis-trams relationship of the halogen and the adjacent acetyl group.
If the halogen and the adjacent acetyl group are on the same side of
the sugar ring (cis), the halogen may be replaced with Walden inver-
sion with the formation of a normal acetate, glycoside, or other sugar
derivative. But if the halogen and the adjacent acetyl group are on
opposite sides of the sugar ring (trans), the acetyl group undergoes an
intramolecular reaction and forms an orthoacetic ester.
The first ketose, for which several acetyl derivatives, halogeno-
acetyl derivatives, and ketosides were obtained in the crystalline
state, is fructose. For obtaining these derivatives of fructose, it was
found [7, 8, 9] that acetylation at low temperature leads to crystalline
derivatives. This observation holds also for Sorbose and may be
valuable if crystalline derivatives of other ketoses are desired. Tetra-
acetyl-d-fructose [7, 8) is an important intermediate for the preparation
of other derivatives of fructose. Several acetates of turanose and
sorbose have been described [10, 11].
The partially acetylated sugar derivatives may be considered in two
classes: (1) Those with free reducing groups, and (2) those with free
hydroxyl groups. The first class may be subdivided further into open-
chain, pyranose and furanose derivatives. The open-chain derivatives
are usually prepared from the acetylated mercaptals by removing the
mercaptal groups by treatment with cadmium carbonate in the pres-
ence of mercuric chloride. A few open-chain derivatives have been
obtained by direct acetylation. The partially acetylated furanoses
and pyranoses are prepared from the halogen acetates by treatment
with moist silver oxide, or from the Orthoacetates by reaction with
aqueous acid. The partially acetylated derivatives containing free
hydroxyl groups are prepared frequently from substances which con-
tain easily removable groups such as triphenylmethyl, benzyl,
p-toluenesulfonyl, ethylidene, and benzilidene groups.
(a) LOW-TEMPERATURE PYRIDINE METHOD OF ACETYLATION [12, 13]
Acetylation of the sugars with acetic anhydride and pyridine at a
low temperature generally yields acetylated products which have the
Polarimetry, Saccharimetry, and the Sugars 487
same structure as the original sugar, and therefore this reaction is of
first importance for studying the structure of the sugars. Since the
product usually consists of a single isomer, the method yields products
that crystallize readily.
(1) PENTAACETYL-o-d-TALOSE.
Method [14]-Five grams of powdered o-d-talose is added to a cold
mixture (0°C) of 35 ml of pyridine and 23 ml of acetic anhydride.
The mixture is shaken at 0°C for several days (until the sugar dis-
solves) and is then poured into 125 ml of ice and water, with stirring.
In a short time pentaacetyl-o-d-talose crystallizes and the crystals are
separated by filtration." The filtrate is extracted with chloroform or
benzene and the extract is washed, first with sodium bicarbonate
solution, then four times with dilute copper sulfate solution, and finally
with water. The chloroform solution is evaporated in vacuo to a
sirup, which is dissolved in ethyl alcohol and allowed to crystallize.
The product is separated, combined with the first crop of crystals, and
recrystallized from hot ethyl alcohol. The total yield is about 8 g.
Pentaacetyl-o-d-talose melts at 106° to 107°C and gives [o]}= +70.2°
(chloroform, c=4).
NOTES
* Acetylated sugars which do not crystallize at this point are extracted with
chloroform. The chloroform solution is washed, as described for the filtrate, and
evaporated to a sirup, which is taken up in petroleum ether or other suitable solv-
ent. In working up new products the best solvent to use can be determined by
experimentation. Frequently crystallization is inhibited by the presence of
pyridine, acetic anhydride, or chloroform. These can be eliminated by careful
washing, evaporation, or by fractional extraction of the residue with suitable
solvents. -
(b) LOW-TEMPERATURE SULFURIC ACID METHOD OF ACETYLATION [15]
In some cases low-temperature acetylation with sulfuric acid as a
catalyst has given crystalline products when other methods were not
successful. This method can be used for either aldoses or ketoses.
(1) PENTAACETYL-3-d-FRUCTOSE.
Method [9].-Forty grams of finely powdered levulose is added to
a cold mixture of 240 ml of acetic anhydride and 10 ml of concentrated
sulfuric acid. The mixture is kept in an ice-salt bath and stirred until
all the sugar goes into solution, after which the solution is shaken with
about 500 ml of ice water, neutralized with sodium bicarbonate, and
separated from the excess of solid bicarbonate by filtration. The
residue on the filter is washed with chloroform to dissolve any acetyl-
ated sugar, and the filtrate is extracted with chloroform for the same
purpose. The chloroform solutions are mixed, dried with calcium
chloride, and distilled in vacuo to a small volume (30 to 50 ml). This
solution is then spread in a thin layer over a flat crystallizing dish and
a strong current of air is passed over the yellowish fluid until the odor
of chloroform disappears and that of acetic anhydride becomes notice-
able. The sirup is then placed in a vacuum desiccator, near potassium
hydroxide and on scratching the dish at intervals, the sirup soon
crystallizes to a solid mass. This is stirred in a mortar with some ether
and filtered. About 16 g (or 20 percent of the theoretical) of pure
pentaacetyl-3-d-fructose is obtained. The substance is easily recrys-
tallized from ether, and by slow evaporation the solution yields
brilliant, clear crystals which melt at 108° to 109° C and give
[o]}=–120.9° (chloroform, c=5).
488 Circular of the National Bureau of Standards
(c) LOW-TEMPERATURE ZINC CHLORIDE METHOD OF ACETYLATION
By variation of the conditions used in the acetylation, with zinc
chloride as a catalyst, it is sometimes possible to prepare acetyl de-
rivatives of different structure. Acetylation of levulose at 0° C gives
a tetraacetylfructopyranose." By continuing the acetylation at a
higher temperature the open-chain pentaacetylfructose is obtained.
NOTE
* The preparation of 1,3,4,5-tetraacetyl-d-fructose is given on page 492.
(1) PENTAACETYL-3-d-MANNos.E.
Method [16].—Four grams of fused zinc chloride is dissolved in 40
g of acetic anhydride, the solution is cooled to 0°C, and 10 g of pow-
dered 8-d-mannose is added in small portions with shaking while the
mixture is kept at 0° C. When all of the sugar is in solution (24
hours), the mixture is poured into ice water and stirred until the in-
soluble residue crystallizes. Then the product is separated by fil-
tration and recrystallized from alcohol. Pentaacetyl-3-d-mannose
melts at 117° to 118°C and gives [o]}=–25.2° (chloroform, c =3).
(d) SODIUM ACETATE METHOD OF ACETYLATION
This is one of the most satisfactory methods for preparing acetyl
sugars, because the catalyst is easily removed by washing with water.
The method can be used for small or large quantities of material.
(1) PENTAACETYL-3-d-GALACTOSE.
Method [17].—Twenty-seven hundred milliliters of acetic anhydride
(technical 90 to 95 percent) is heated to about 100° C and 220 g of
anhydrous sodium acetate * is added. In small portions, 500 g of
d-galactose is added with stirring in the course of an hour, and when
the addition is completed, the solution is heated at about 100° C for
about 1 hour. The solution is cooled to room temperature, poured
into 8 liters of ice water, and stirred for several hours. The acety-
lated product is then extracted with a total of 6 liters of benzene
(technical) or with chloroform.” The extracts are washed with
water, dried, and concentrated under reduced pressure to a thick
sirup, which is allowed to crystallize. The crystals are separated by
filtration and washed with mixtures of benzene and petroleum ether.
The crude material is recrystallized by dissolving it in the minimum
amount of boiling ethyl alcohol, adding a decolorizing carbon, filtering
while hot, and allowing the solution to cool. The yield of recrystal-
lized material is 550 g, and about 75 g more can be obtained from the
º mother liquors and from those remaining after the recrystal-
ization.
Pentaacetyl-3-d-galactose has a melting point of 142° C and an
optical rotation, [o]}= +25° (in chloroform). From the mother
liquors other isomeric acetates may be obtained [4,5].
NOTES
* Anhydrous sodium acetate is prepared by heating the hydrate in a stainless-
steel container until the product has melted, solidified, and finally melted again.
The hot liquid is poured in a thin layer over a slab of stone and the product is
ground in a mortar and bottled. The slight charring which occurs by this method
can be avoided by drying the acetate in vacuo at a lower temperature.
* The sugar must be added slowly; otherwise the reaction may suddenly become
too vigorous.
Polarimetry, Saccharimetry, and the Sugars 489
* With many sugars the acetylated product crystallizes from solution, in which
case the extraction may be omitted and the crude product is separated by filtra-
tion, and recrystallized from alcohol.
(e) HIGH-TEMPERATURE ZINC CHLORIDE METHOD OF ACETYLATION [18]
Acetylation with hot acetic anhydride and zinc chloride usually
gives the alpha isomer. The zinc chloride is dissolved in hot acetic
anhydride and the sugar is added in small portions. After the re-
action is complete the mixture is cooled and then poured into ice water.
The acetylated sugar is separated by extraction or by filtration. The
high-temperature zinc chloride acetylation can be used for converting
glycosides and fluoro-acetyl derivatives to the fully acetylated sugars.
(1) OCTAACETYL-4-(6-d-GLU CoSIDO)-o-d-MANNOSE.
Method [19].—A solution of 30 g of fluoro-heptaacetyl-4-glucosido-
mannose and 2 g of fused zinc chloride in 150 ml of acetic anhydride is
heated on the steam bath for 30 minutes and is then poured into a
large amount of ice water. After the mixture is stirred for several
hours, the crystallized product is separated by filtration and washed
with methyl alcohol. About 22.5 g of octaacetyl-4-(6-d-glucosido)-o'-
d-mannose is obtained. After recrystallization from methyl alcohol
the pure material melts at 202° to 203° C and gives [o]}=-|-36.2°
(chloroform, c=2).
(f) PREPARATION OF ACETYL DERIVATIVES FROM HALOGENO-ACETYL
DERIVATIVES
(1) TETRAACETYL-3-d-xYLOSE.
Method [20].-Four grams of bromo-triacetylxylose is dissolved in
75 ml of glacial acetic acid and the solution is shaken for a few min-
utes * with 5 g of silver acetate. A small amount of a decolorizing
carbon is added, the solution is filtered, diluted with water, and
extracted with chloroform. The chloroform extract is washed with
water and is then evaporated under reduced pressure to a thick sirup,
which is dissolved in ether and allowed to crystallize. The pure
tetraacetyl-3-d-xylose “ has a melting point of 128°C and gives
[o]}=–24.7° (chloroform, c = 5) [21].
The procedure described may also be used with chloroacetyl
derivatives, but the reaction is carried out at a temperature of 50°
to 60° C.
NOTES
1 This compound may be made according to the procedure described for bromo-
tetraacetylglucose on page 500.
* A small portion of the solution after filtration should give a negative Beilstein
copper-wire test for halogen.
* For some sugars quantities of the alpha isomer are also produced.
(g) INTERCONVERSION OF ACETATES
(1) PREPARATION OF PENTAACETYL-o-d-MANNOSE FROM PENTAACE-
TYL-3-d-MANNOSE. e
Method [16].—Twenty grams of the pentaacetyl-3-d-mannose, is
dissolved in 30 ml of acetic anhydride containing 1 g of fused zinc
chloride, and the solution is heated on the steam bath until no further
change in the rotation is observed (about 30 minutes). The Solution
is cooled, mixed with 500 ml of ice water, and the acid neutralized
with sodium bicarbonate. A thick gummy substance separates and
490 Circular of the National Bureau of Standards
is removed, washed in cold water, and dissolved in boiling water.
Upon cooling, the solution deposits about 7 g of the crystalline
pentaacetyl-o-d-mannose, which is further purified by recrystalliza-
tion from hot water. The purified material melts at 64°C and gives
[o]}= +55.0° (chloroform, c=4).
(2) PREPARATION OF HEXAACETYL-o-d-o-MANNoHEPTOSE FROM
HEXAACETYL-3-d-o-MANNoHEPTOSE,-Alpha acetates can be prepared
from beta acetates by treatment with sulfuric acid in a mixture of
acetic anhydride and acetic acid. The isomerizing reagent is prepared
by adding dropwise 4.6 ml of concentrated sulfuric acid to a mixture
of 140 ml of acetic anhydride (95 percent) and 60 ml of glacial acetic
acid cooled in a bath of ice and salt.
Method [3].-A solution of 5 g of hexaacetyl-3-d-o-mannoheptose in
25 ml of the isomerizing reagent is prepared and allowed to stand at
20°C for 24 hours. The mixture is then poured into ice water, and
the product which separates is washed with sodium bicarbonate
solution and again with water. The acetate is then dissolved in
ether and after the addition of petroleum ether to saturation, hexa-
acetyl-a-d-o-mannoheptose crystallizes. The yield obtained by
Montgomery and Hudson was 3.8 g. The purified product melts at
75° to 76°C and gives [o]}=-|- 120.8° (chloroform, c=1).
Essentially the same method can be used for transforming other
acetylated pyranosides [22]. Acetylated furanosides frequently give
open-chain acetates.
(h) PREPARATION OF OPEN-CHAIN ACETATES
In a few cases, particularly with the ketoses, open-chain acetyl
derivatives may be prepared by direct acetylation of the sugar (see
p. 491). In general, however, they are obtained by the acetylation
of open-chain derivatives, such as the mercaptals [23] and Oximes
[24], and the subsequent regeneration of the carbonyl group by re-
moval of the substituent group. The mercaptals have been most
commonly used as the starting materials. However, in cases where
the mercaptals are unknown or when the conditions for their forma-
tion are too severe (as for disaccharides), the Oximes and semicar-
bazones are preferable. The benzoyl-aldehydo sugars have also
been prepared.
(1) PENTAACETYL-aldehydo-d-GLUcos E.
Method [23].–Five grams of glucose ethyl mercaptal (prepared as
described for galactose on p. 521) is acetylated by the pyridine
method described on page 486. The sirup resulting from the acetyla-
tion crystallizes after standing for a week or two in the ice box. The
crystalline material, separated by one filtration and washed with
cold water, weighs about 8 g. The material is recrystallized from
aqueous methyl alcohol to give pure pentaacetylglucose ethyl mercap-
tal which melts at 45° to 47°C.
A solution of 90 ml of acetone and 45 ml of water is placed in a
three-necked round-bottomed flask provided with a reflux condenser
and a mercury-sealed mechanical stirrer. Pentaacetylglucose ethyl
mercaptal (25.2 g) is then dissolved in the solution, and an excess of
washed cadmium carbonate (45 to 50 g) is added. A solution of 49.5
g of mercuric chloride in 72 ml of acetone is then gradually added to
the rapidly stirred mixture and the stirring continued at room temper-
Polarimetry, Saccharimetry, and the Sugars 491
ature for 24 hours, during which time small amounts of cadmium car-
bonate are added. After this period the rapidly stirred solution is
heated in a water bath to 50°C and held at this temperature for 15
minutes. The temperature is then raised and the solution, after
being refluxed gently for 15 minutes, is filtered into a flask containing
cadmium carbonate. The precipitate (EtS-Hg-Cl) is washed with
acetone. The filtrate containing an excess of cadmium carbonate is
concentrated in vacuo at 30° to 35°C to a thick sirup from which
water is removed by repeated addition of acetone, and distillation.
The final residue is extracted with warm chloroform and the chloro-
form evaporated in a vacuum desiccator. The crude product which
crystallizes is separated and dissolved in 50 ml of hot acetone. Alcohol-
free ether (25 ml) is added to the solution and then petroleum ether
to saturation. After several hours at 0°C the crystalline material is
separated, washed with an ether-acetone solution and dried. About
10 g of material is obtained from the first crystallization and about
2 g more may be obtained by adding petroleum ether to the mother
liquors. The pure pentaacetyl-aldehydo-d-glucose has a melting point
of 116° to 118°C and gives [o] }= —4.8° (chloroform, c=5).
(2) PENTAACETYL-keto-d-FRUCTOSE
Method [8, 25].—Ten grams of finely powdered levulose is added in
one portion to a solution of 1 g of fused zinc chloride in 100 ml of acetic
anhydride cooled in an ice bath. The mixture is stirred vigorously at
0°C for 4 hours, during which time most of the sugar dissolves. The
temperature is then kept at 20° to 25°C for 1 hour and finally at 50°C
for 2 hours. The cooled solution is stirred with an equal volume of
ice water for 1% hours and is then further diluted and neutralized with
an excess of sodium bicarbonate. The chloroform solution of the
gummy precipitate, united with the chloroform extracts of the water
solution, is dried with calcium chloride, filtered, and evaporated in
vacuo to a sirup which is dissolved in about 50 ml of absolute ether.
This solution on standing overnight in the ice box deposits about
10 g of crude crystalline pentaacetyl-keto-d-fructose.
The pure pentaacetyl-keto-d-fructose melts at 70°C and gives
[o] }=-|-34.7° (chloroform, c=8).
(i) PREPARATION OF PARTIALLY ACETYLATED PYRANOSES
Acetates containing free reducing groups are prepared by treating
the halogeno-acetyl sugars with moist silver oxide or carbonate.
They can be prepared also by the hydrolysis of orthoesters and
occasionally by partial acetylation.
(1) HEPTAACETYL-4-(6-d-GLUCOSIDO)-d-MANNOSE
Method [26]-Two grams of bromo-heptaacetyl-d-glucosidoman-
nose is added to 50 ml of cold acetone containing 5 ml of water and 5
g of silver carbonate. The mixture is shaken until all the bromine is
converted into silver bromide, which is separated by filtration. The
solution is allowed to evaporate spontaneously in an open beaker.
Slender, prismatic, needlelike crystals separate during the course of
several hours. The crystals are collected upon a filter and washed
with water. The yield is about 1% g. After recrystallization from
hot water, in which they are difficultly soluble, the crystals melt
at 110°C and give [o]}=-|-11.7° (chloroform, c=5).
492 Circular of the National Bureau of Standards
(2) HEXAACETYL-4-(6-d-GLUcosido)-d-MANNos.E.
Method [26]-A 5-g sample of 1, 2-(hexaacetyl-4-glucosido-mannose)
methyl orthoacetate is suspended in 50 ml of cold absolute methyl
alcohol, and 4 ml of methyl alcohol containing 0.34 g of dry hydrogen
chloride is added. The flask is shaken until solution is complete
(about 1 minute) and then allowed to stand at room temperature.
After 10 minutes the acid solution is mixed with a paste consisting of
10 g of silver carbonate and 2 ml of water. The mixture is stirred until
a negative test for halogen is obtained; then the silver salts are removed
by filtration, and the solution is evaporated in vacuo to a thick sirup
from which hexaacetyl-4-glucosidomannose crystallizes in rectangular
prisms. It is difficulty soluble in water, fairly soluble in ether, and
very soluble in chloroform. The crude product (3.8 g) is recrystallized
from hot ethyl alcohol.
Hexaacetyl-4-(6-d-glucosido)-d-mannose melts at 171°C and gives
|o]}}= +21.7° (chloroform, c=2).
(3) 1,3,4,5-TETRAACETYL-d-FRUCTOSE.
Method [8, 27].—Sixty-six grams of freshly powdered levulose is
added to a solution of 6 g of anhydrous zinc chloride in 340 ml of
acetic anhydride which is cooled by an ice-and-salt mixture. During
16 hours of stirring at 0°C the fructose gradually disappears and small
needles crystallize from the solution." Then the mixture is stirred at
– 15°C for 1 hour and filtered. The unwashed crystals are transferred
to a desiccator and dried over sodium hydroxide in vacuo until free
from acetic anhydride. About 47 g of crude tetraacetylfructose is
obtained. On neutralizing the mother liquor with solid sodium bicar-
bonate, a half-solid, sticky mass separates. This is dissolved in
chloroform, the solution is washed three times with water, dried with
calcium chloride, and concentrated under reduced pressure to a thin
sirup. The sirup is dissolved in ether, poured into a crystallizing
dish, and allowed to crystallize in a desiccator. About 13 g of the
tetraacetate is obtained. The combined crops are dissolved in chloro-
form, and the solution, after filtering, is concentrated in vacuo to a
thin sirup. Upon addition of ether, and cooling, the substance crystal-
lizes in about 45-percent yield. Pure 1,3,4,5-tetraacetyl-d-fructose
melts at 131° to 132°C and gives [a]}=–91.6° (chloroform, c =3).
NOTE
! If the temperature is allowed to rise, pentaacetyl-keto-fructose is formed [25]
(see p. 491).
(j) PREPARATION OF ORTHOACETATES
(1) 1,2-(HEXAACETYL-4-GLUCOSLDOMANNOSE) METHYL ORTHOACE-
TATE AND METHYL HEPTAACETYL-4-(6-d-GLUCoSIDO)-3-d-MANNO-
PYRANOSIDE.
Method *[26].—Twenty-five grams of bromo-heptaacetyl-4-glucosido-
mannose is mixed at 0° C* with 25 g of dry freshly prepared silver
carbonate * in 250 ml of anhydrous methyl alcohol. After being shaken
for 30 minutes, the solution is filtered. The filtrate, which should give
a negative Beilstein copper-wire test for halogen, is concentrated in
vacuo to a thick sirup, which is taken up with ether and allowed to
crystallize. The evaporated mother liquor when taken up with
alcohol deposits additional small crops of crystals. About 17 g of
crystalline material is obtained, which consists of the hexagonal or
diamond plates of 1,2-(hexaacetyl-4-glucosidomannose) methyl ortho-
Polarimetry, Saccharimetry, and the Sugars 493
acetate mixed with a small amount of the acetylated glycoside.” The
crystals are fractionally recrystallized from absolute ethyl alcohol"
and 14 g of the pure Orthoacetate derivative is obtained. It melts
at 167° C and gives [o]}= –13° (chloroform, c=3). The material
left after the separation of the Orthoacetate consists of the acetylated
beta glycoside and some of the orthoacetate. This mixture is sep-
arated by fractional crystallization, first from water and then from
absolute alcohol. In these solvents the acetylated beta glycoside is
slightly less soluble than the orthoacetate. The melting point of the
pure methyl heptaacetyl-4-(6-d-glucosido)-3-d-mannopyranoside, of
which about 2 g is obtained, is 178° C, and the rotation is [o]}=
—23.2° (chloroform, c=3). -
A Small quantity (0.5 g) of methylheptaacetyl-4-(6-d-glucosido)-o-d-
mannoside” is obtained from the original mother liquor after the
Orthoacetate and the acetylated beta glycoside have been separated.
Methyl heptaacetyl-4-(3-d-glucosido)-o-d-mannopyranoside melts at
185°C and gives [o]}=-|-29.3° (chloroform, c=2).
NOTES
* This method may be used for the preparation of both orthoacetates and
8-methyl glycosides. Orthoacetates are produced in good yield by application of
the method to halogeno-acetates which have trans configurations for the halogen
and adjacent acetyl groups [6].
* The proportions of the products obtained vary with the experimental condi-
tions. By conducting the reaction at the temperature of boiling methyl alcohol,
Haworth, Hirst, Streight, Thomas, and Webb [28] found that the acetylated
alpha glycoside crystallizes readily. -
* Prepared as described on page 514.
* The Orthoacetate derivatives are very reactive in the presence of traces of
acids. Hence all solvents should be acid-free.
(k) METHODS FOR REMOVING ACETYL GROUPS
(1) CATALYTIC BARIUM METHYLATE METHOD. The catalytic bari-
um methylate method originated by Isbell [29] is one of the most
satisfactory methods for the deacetylation of the acetylated sugars
and related substances. It resembles the sodium methylate method
of Zemplén [30]. In both methods the alcoholate acts catalytically
and merely facilitates the conversion of the acetyl groups to methyl
acetate. Barium methylate is more convenient than sodium methy-
late because the barium may be removed readily and stock solutions
may be purified before use by filtration to remove any barium hydro-
xide or carbonate. The reagent is prepared by adding powdered
barium oxide to absolute methyl alcohol. The barium oxide reacts
with the alcohol, forming barium methylate and barium hydroxide.
The barium hydroxide is insoluble in the alcoholic solution and is
separated by filtration. The strength of the filtered solution is ascer-
tained by titration with 0.1 N aqueous sulfuric acid. The method is
illustrated by the following example:
Deacetylation of methyl heptaacetyl-4-(6-d-glucosido)-3-d-mammopyra-
noside [26, 29].—Dry methyl heptaacetyl-4-(6-d-glucosido)-6-d-man-
nopyranoside (1.5 g) is dissolved in 30 ml of cold anhydrous methyl
alcohol. Two milliliters of 0.4 N barium methylate solution in methyl
alcoholis added, and the solutionis allowed to standin the refrigerator for
24 hours. After the solution has been tested for excess barium methyl-
323414°–42—33
494 Circular of the National Bureau of Standards
ate,” the barium is precipitated by the addition of an equivalent quan-
tity of sulfuric acid, or by carbonation. The precipitate is removed
by filtration and the filtrate evaporated to a thick sirup which is
allowed to crystallize. The crystalline mass is triturated with abso-
lute alcohol and after separation weighs about 0.7 g. Two recrys-
tallizations from ethyl alcohol yield pure methyl 4-(6-d-glucosido)-3-d-
mannopyranoside hemihydrate, which melts at 229° C and gives
|o]}=–48.5° (water, c=4). Other acetylated sugar derivatives may
be deacetylated in similar manner.
(2) RAPID DEACETYLATION witH HOT SoDIUM METHYLATE.-The
acetyl-glycosides, acetyl-alcohols, and other acetylated products
without a free reducing group are rapidly deacetylated by a small
amount (one six-hundredth of the theoretical quantity) of sodium or
barium methylate at the boiling point of the methyl alcoholic solution
of the substance. The amount of sodium or barium acetate formed
is so small that for ordinary purposes it is not separated. The method
is advantageous for acetylated substances of low solubility, but it
cannot be used for substances having a free reducing group or for
those sensitive to alkali. The method is illustrated by the following
example: -
Deacetylation of pentaacetylsalicin, [31].--To 80 ml of absolute
methyl alcohol, 20 g of pentaacetylsalicin and 4 ml of 0.1 N sodium
methylate solution are added and the mixture is boiled for 5 to 10
minutes on a water bath. The cool solution, upon standing overnight,
º about 10 g of salicin (87 percent of theory), which melts at
2010 C.
(3) DEA CETYLATION WITH AN ExCESS OF ALKALI.-If the sugar
derivative contains toluenesulfonyl or other groups which react
stoichiometrically with barium or sodium methylate in methyl alcohol
to form salts, an excess of alkali must be used. Barium hydroxide in
aqueous solution [32], barium methylate in alcoholic solution [33], and
sodium hydroxide in acetone [34] have been employed.
(1) QUANTITATIVE DETERMINATION OF ACETYL GROUPS
Since the percentages of carbon and hydrogen in the various acetyl
derivatives of the carbohydrates differ only slightly, the number of
acetyl groups in a carbohydrate derivative is usually determined by
titration of the acetic acid formed either directly or indirectly by the
hydrolysis of the acetyl groups. The determination may be conducted
by several methods, which will be considered in three groups: (1)
methods which depend on hydrolysis in alkaline solution, (2) methods
which depend on hydrolysis in acid solution, and (3) methods which
depend on the production and distillation of ethyl acetate.
The methods employing alkaline hydrolysis are applicable to the
determination of acetyl groups in carbohydrate derivatives which
under the conditions of the method do not give other acidic or basic
decomposition products. By conducting the hydrolysis at 0°C, as
described by Brauns [35], decomposition of the sugar is largely avoided
and satisfactory results can be obtained with ketoses and other sugars
which are relatively sensitive to alkalies. But in some cases, as for
*Since moisture or acids in the original sirup will decompose the barium methylate, it is well to test the
deacetylated mixture to see if an excess of barium methylate is present. This may be done by diluting
a few milliliters with water and adding several drops of phenolphthalein solution. A definite red color
indicates a sufficient excess. If the test is not positive, add more barium methylate solution to the deace-
tylation mixture and allow 24 hours more for the deacetylation to be completed.
Polarimetry, Saccharimetry, and the Sugars 495
example with tetraacetyl-d-ribosido-dihydroxyacetone [36], the alkali,
even at 0°C, results in the formation of acidic decomposition products;
hence, the results obtained by alkaline hydrolyses are considerably
greater than the theoretical values. Certain orthoester groups are
relatively stable to alkaline hydrolysis but are very sensitive to acid
hydrolysis. Consequently the Orthoester groups can be determined
by the difference in the results obtained from hydrolyses in acid and
in alkaline solution. In the event that the substance contains acetyl
groups attached to nitrogen, the ethyl acetate method of Perkin [37]
as modified by Freudenberg and Harder [38] gives the combined
O-acetyl and N-acetyl groups, while the alkaline hydrolysis at 0°C
gives only the O-acetyl [39]. In the ethyl acetate method the acetyl
derivative is heated in acid solution with ethyl alcohol, the ethyl ace-
tate which is formed is distilled and saponified with standard alkali.
(1) DETERMINATION OF ACETYL GROUPS BY ALKALINE HYDROLYSIs.
Method [37].-A 0.4-g sample of finely powdered tetraacetylfructose
is shaken with 75 ml of 0.1 N sodium hydroxide at 0°C. The saponi-
fication is complete in 2 to 5 hours, when a clear solution is obtained.
The excess of sodium hydroxide is titrated with 0.1 N sulfuric acid
(phenolphthalein indicator). The difference in the amount of alkali
added and the acid used in the titration gives the amount of acetic
acid formed. The results usually agree with the theoretical value
within 0.5 percent.
The more insoluble acetylated sugars and glycosides dissolve very
slowly in aqueous sodium hydroxide and require a long time for saponi-
fication. This difficulty may be overcome by the following procedure,
which uses acetone as a solvent [40]:
One-half gram of the substance is dissolved in 50 ml of acetone.
The solution is cooled in an ice-and-salt mixture and 100 ml of 0.1 N
aqueous potassium hydroxide is added dropwise. The solution is kept .
for 2 hours at the temperature of the ice-and-salt mixture. Then the
excess alkali is titrated with 0.2 N hydrochloric acid. A blank
control test is run and the results are corrected for its value.
(2) DETERMINATION OF ACETYL GROUPS BY ACID HYDROLYSIs.
Method [41].-A half-gram sample of the finely powdered substance
is mixed with 100 ml of 0.25 N sulfuric acid and boiled for 5 hours
under a reflux condenser. The solution is cooled and titrated with
0.1 N sodium hydroxide. The amount of acetic acid formed by the
hydrolysis of the acetyl groups is equal to the difference between the
amount of sulfuric acid added and the amount of alkali used.
(3) DETERMINATION OF ACETYL GROUPS BY THE ETHYL ACETATE
METHOD.
Method [38].-The determination is made in the apparatus illus-
trated in figure 111. Flask A has a volume of 100 ml and B a volume
of 150 ml. The tubes F and G must have a minimum inside diameter
of 5 mm. The weighed sample (0.3 to 0.4 g), 30 ml of absolute alco-
hol, 5 g of p-toluenesulfonic acid, and a few boiling stones are intro-
duced into flask A, and 10 ml of absolute alcohol is placed in flask B.
Water is allowed to flow through the condensers C, D, and E. Flask
B is cooled in an ice bath, and flask A is heated by a water bath at
100° C while its contents are allowed to reflux for 10 minutes. The
bath temperature is lowered to 95° C (at which point it is kept during
the subsequent operations), the reflux condenser, C, is emptied of
496 Circular of the National Bureau of Standards
water, and the contents of flask A are allowed to distill for 15 minutes
into flask B. Then 20 ml of absolute alcohol is introduced into flask
A from the dropping funnel. The contents of flask A are refluxed
for 10 minutes while water again flows through condenser C. Con-
denser C is then emptied and the material in flask A distilled into flask
B for 10 minutes. With condenser C still empty, 20 ml of absolute
alcohol is added dropwise to flask A over a period of 15 minutes while
simultaneous distillation takes place. The distillation is continued
FIGURE 111.-Apparatus for the determination of acetyl groups by the ethyl acetate
method.
for 10 minutes." When the distillation is finished, 30 ml of 0.2 N
sodium hydroxide * is added to flask B through the tube of condenser
E. The temperature of flask A is kept at 80°C, the cold bath of flask
B is replaced by a hot-water bath, and the contents of flask B are
refluxed for 10 minutes. Flask B is again cooled and removed from
the apparatus. After the contents have been diluted with 30 ml of
water, they are titrated with 0.2 N sulfuric acid (phenolphthalein
indicator). A blank control determination is run, and the titration
is corrected for its value. Freudenberg and Harder state that the
normal deviation from the theoretical value is −0.1 to +0.4 percent.

Polarimetry, Saccharimetry, and the Sugars 497
NOTES
1 The experimental conditions as given are suitable for most sugar derivatives.
In case the sample contains acetyl groups attached to nitrogen, the temperature
of the bath for the flask A is kept at 100° C during the entire esterification reaction
and the distillations. It is changed only during the final saponification, which is
carried out as described in the O-acetyl directions at 80° C. The first refluxing
time is lengthened from 10 minutes to 45 minutes and the second from 10 minutes
to 30 minutes.
* The standardization of the sodium hydroxide solution is made by diluting
a definite volume with an equal amount of water, adding 2 volumes of alcohol,
and titrating with 0.2 N sulfuric acid, using phenolphthalein indicator.
(4) DETERMINATION OF ACETYL GROUPS AND HALOGEN IN HALO-
GENo-ACETYL DERIVATIVEs.—The analytical results obtained by al-
kaline or acid hydrolysis of halogeno-acetyl sugars represent the total
number of acid groups. However, a quantitative determination of
the halogen may easily be made on the hydrolyzed solution. If
alkaline saponification is employed, the excess alkali is titrated with
standard nitric acid. The halogen in the solution is then determined
in the conventional manner by precipitation as silver chloride, bromide,
or iodide, or as calcium fluoride.
(m) REFERENCES
. S. Hudson, J. Ind. Eng. Chem. 8, 380 (1916).
L. Jungius, Z. physik. Chem. 52, 101 (1905).
Montgomery and C. S. Hudson, J. Am. Chem. Soc. 56, 2463 (1934).
S. Hudson and H. O. Parker, J. Am. Chem. Soc. 37, 1589 (1915).
S. Hudson and J. M. Johnson, J. Am. Chem. Soc. 38, 1223 (1916).
S. Isbell, Ann. Rev. Biochem. 9, 70 (1940).
H. Brauns, Proc. Roy. Acad. Amsterdam 10, 563 (1907–1908).
S. Hudson and D. H. Brauns, J. Am. Chem. Soc. 37, 2738 (1915).
S. Hudson and D. H. Brauns, J. Am. Chem. Soc. 37, 1283 (1915).
. Pacsu, J. Am. Chem. Soc. 54, 3649 (1932).
B. Cramer and E. Pacsu, J. Am. Chem. Soc. 59, 711, 1467 (1937).
( lººd and P. Roth, Liebigs Ann. Chem. 331, 362 (1904); 353, 109
1907).
[13] E. Fischer and R. Oetker, Ber. deut. chem. Ges. 46, 4029 (1913).
[14] W. W. Pigman and H. S. Isbell, J. Research NBS 19, 189 (1937) RP1021.
[15] Zd. H. Skraup and J. Koenig, Ber. deut. chem. Ges. 34, 1115 (1901).
[16] C. S. Hudson and J. K. Dale, J. Am. Chem. Soc. 37, 1280 (1915).
[17] E. Erwig and W. Koenigs, Ber. deut. chem. Ges. 22, 2207 (1889).
[18] E. Erwig and W. Koenigs, Ber. deut. chem. Ges. 22, 1464 (1889). £,
[19] D. H. Braums, J. Am. Chem. Soc. 48, 2784 (1926). k-3
[20] J. K. Dale, J. Am. Chem. Soc. 37, 2745 (1915).
[21] C. S. Hudson and J. M. Johnson, J. Am. Chem. Soc. 37, 2748 (1915).
[22] R. M. Hann and C. S. Hudson, J. Am. Chem. Soc. 56, 2465 (1934).
[23] M. L. Wolfrom, J. Am. Chem. Soc. 51, 2188 (1929).
[24] M. L. Wolfrom, L. W. Georges, and S. Soltzberg, J. Am. Chem. Soc. 56,
1794 (1934).
[25] F. B. Cramer and E. Pacsu, J. Am. Chem. Soc. 59, 1148 (1937).
26] H. S. Isbell, BS J. Research 7, 1115 (1931) RP392.
27] E. Pacsu and F. W. Rich, J. Am. Chem. Soc. 55, 3022 (1933).
28] W. N. Haworth, E. L. Hirst, H. Streight, H. Thomas, and J. Webb, J. Chem.
Soc. 1930, 2643.
[29] H. S. Isbell, BS J. Research 5, 1185 (1930) RP253.
[30] G. Zemplén, Ber. deut. chem. Ges. 59, 1258 (1926).
[31] G. Zemplén and E. Pacsu, Ber. deut. chem. Ges. 62, 1613 (1929).
[32] C. S. Hudson and D. H. Brauns, J. Am. Chem. Soc. 38, 1216 (1916).
[33] W. Weltzien and R. Singer, Liebigs Ann. Chem. 443, 104 (1925).
[34] A. Kunz and C. S. Hudson, J. Am. Chem. Soc. 48, 1982 (1926).
[35]. D. H. Brauns, Verslag Koninkl. Akad. Wetensch. Amsterdam, 577, (1908).
[36] C. W. Klingensmith and W. L. Evans, J. Am. Chem. Soc. 61, 3012 (1939).
[37] A. G. Perkin, J. Chem. Soc. 87, 107 (1905).
[38]. K. Freudenberg and M. Harder, Liebigs Ann. Chem. 433, 230 (1923).
-
is#.
º-
498 Circular of the National Bureau of Standards
[39] M. Hºlſton, M. Konigsberg, and S. Soltzberg, J. Am. Chem. Soc. 58, 490
[40] A. Kunz, J. Am. Chem. Soc. 48, 1982 (1926).
[41] D. H. Brauns, J. Am. Chem. Soc. 47, 1294 (1925).
3. HALOGENO-ACETYL DERIVATIVES
General characteristics.-Since the chloro- and bromo-acetyl deriva-
tives may be used for the synthesis of compound sugars and for the
preparation of other substances, they rank among the most important
Sugar derivatives. The alpha derivatives may be prepared by treat-
ing the acetyl sugars with the corresponding hydrogen halides, pref-
erably in acetic acid solution or by treating the acetyl sugars with
phosphorus pentachloride, titanium tetrachloride, or other suitable
halide. Under mild conditions the glycosidic acetyl group is replaced
and the alpha halogen derivative is obtained. Prolonged treatment
and higher temperatures result in the formation of dihalogen substi-
tution products and in complex reactions which give new sugars of
different configuration. The beta-chloro-acetyl derivatives are pre-
pared by treating the alpha-bromo-acetyl derivatives with silver
chloride.
The fluoro- and chloro-acetyl derivatives are usually stable and
may be kept for long periods, but the bromo-, and particularly the
iodo-acetyl derivatives tend to decompose at room temperature.
The stability of the halogeno-acetyl derivatives decreases in the order
of F, Cl, Br, and I, while the reactivity increases in the same order.
Although general methods of halogenation can be applied in many
cases, modifications of these general methods are often necessary in
order to obtain the desired derivatives in crystalline condition. This
is especially the case for the halogeno-acetyl derivatives of fructose,
mannose, maltose, and melibiose. Thus Fischer and Oetker [1] were
not able to prepare crystalline bromo-tetraacetylmannose, while
Micheel and Micheel [2], by a slight modification of their procedure,
obtained the crystalline compound. The special procedure necessary
to induce bromo-heptaacetylmaltose to crystallize is given by
Brauns [3].
(a) PREPARATION OF FLUORO-DERIVATIVES
(1) 1-FLUORO-2,3,4,6-TETRAACETYL-o-d-GLUCOSE.
Method [4].—The preparation is best carried out in a copper ap-
paratus consisting of a retort, water-jacketed condenser, and receiver,
which are connected by ground joints. The condenser is cooled with
ice water and the receiver by an ice-salt bath. About 80 g of dry
potassium hydrogen fluoride is placed in the retort and 10 g of pen-
taacetyl-3-d-glucose in the receiver. The apparatus is connected, the
retort is heated to a red heat, and the hydrogen fluoride distilled into
the pentaacetylglucose over a period of about 30 minutes.” The cold
liquid in the receiver is then poured into a separatory funnel containing
ice, water, and chloroform. The mixture is shaken and the chloro-
form separated. The aqueous layer is extracted several times with
chloroform. The combined extract is washed several times with
water and dried with anhydrous sodium sulfate. The chloroform
solution is evaporated to a sirup which, after the addition of petroleum
ether, yields crystalline 1-fluoro-2,3,4,6-tetraacetyl-o-d-glucose. The
crystalline mass is dissolved in a small amount of hot ethyl alcohol and
the solution is filtered and allowed to cool, whereupon crystallization
Polarimetry, Saccharimetry, and the Sugars 499
takes place. About 4 g of the crystalline substance is obtained, which
may be purified by several recrystallizations from hot ethyl alcohol.
1-Fluoro-2,3,4,6-tetraacetyl-o-d-glucose melts at 108°C and gives
[o]}=-|-90.1° (chloroform, c=3).
NOTES
* A supply of dry potassium hydrogen fluoride is prepared by dehydrating
commercial potassium hydrogen fluoride. This is advantageously performed by
heating the crushed salt gradually to 140° C in a vacuum oven. The dry salt is
stored in copper beakers in a vacuum desiccator. Recently anhydrous hydro-
fluoric acid in iron containers has been put on the market and could advantageously
be used. Precautions for handling anhydrous hydrofluoric acid are given by
Ruff and Plato [5]. Adequate ventilation should be provided.
* The amount of hydrogen fluoride produced may be determined by weighing
the receiver before and after the distillation. About 20 g should be condensed
in the receiver.
(b) PREPARATION OF CHLORO-DERIVATIVES
(1) 1-CHLORO-2,3,4,6-TETRAACETYL-o-d-GLUCOSE.
Method [6].-Ten grams of dry pentaacetyl-3-d-glucose dissolved in
70 g of purified chloroform is mixed with a solution of 4.9 g of titan-
ium tetrachloride in 25 g of purified chloroform. The yellow precipi-
tate which forms dissolves after shaking, with the simultaneous lib-
eration of heat. The solution is refluxed on a water bath for 3 hours,
during which time care is taken to exclude moisture. The yellow
solution is cooled and mixed with ice water. The colorless chloroform
layer is washed several times with water, dried with calcium chloride,
and evaporated under reduced pressure. The colorless sirup is dis-
solved in absolute ether, and the solution is saturated with petroleum
ether. After the introduction of seed crystals,” crystallization takes
place. About 7 g of crystalline material separates, and from the
mother liquor another 1.5 g may be obtained. 1-Chloro-2, 3, 4, 6–
tetraacetyl-o-d-glucose melts at 75° to 76°C and gives [o]}= + 166.1°
(chloroform, c=2).
NOTES
1 USP chloroform is washed several times with water, dried with calcium chlor-
ide, and distilled over phosphorus pentoxide.
* Seed crystals are obtained by stirring a little of the sirup with absolute alcohol.
(2) 1-CHLORO-2,3,4,6-TETRAACETYL-o-d-MANNOSE.
Method [7].-Fifteen grams of crystalline pentaacetyl-3-d-mannose
is dissolved in 30 ml of dry chloroform in a glass-stoppered Erlen-
meyer flask, and 4 g of dry (sublimed) aluminum chloride and 9 g of
phosphorus pentachloride are added. The mixture is slightly warmed
on the steam bath in order to accelerate the reaction. In about 1 hour
nearly all the aluminum chloride and phosphorus pentachloride go
into solution and the mixture turns slightly green. The reaction
product is then cooled, poured into ice water, and the product is
extracted with chloroform. The chloroform extracts are washed sev-
eral times with ice water, dried with anhydrous sodium sulfate, and
evaporated in vacuo. The sirupy residue may be dried in a vacuum
desiccator over paraffin wax in order to remove traces of chloroform.
When the dry colorless residue is stirred with a small amount of
petroleum ether, crystallization takes place. The product is recrys-
tallized by reducing it to a powder which is extracted, first with a
500 Circular of the National Bureau of Standards
100-ml portion of petroleum ether (which is kept separate as it con-
tains most of the impurities), and then four times with 200-ml portions.
By evaporating the petroleum ether in air, about 9 g of crystals is
obtained. 1-Chloro-2, 3, 4, 6-tetraacetyl-o-d-mannose melts at 81°C
and gives [o]}= +89.9° (chloroform, c=2).
(c) PREPARATION OF BROMO-DERIVATIVES
(1) 1–BROMO-2,3,4,6-TETRAACETYL-o-d-GLUCOSE.
Method [8, 9]'.-A mixture of 200 g of pentaacetyl-3-d-glucose” and
130 ml of a glacial acetic acid solution of hydrogen bromide (saturated
at 0°C) * is prepared at room temperature, and the solution is allowed
to stand for 2 hours. The solution is then diluted with 800 ml of
chloroform, poured into 3 liters of ice and water, and stirred rapidly."
The chloroform layer is separated and the aqueous phase extracted
once more with 200 ml of chloroform. The chloroform extracts are
washed twice with ice water, dried with calcium chloride, and evapo-
rated in vacuo " to a thick sirup which is taken up with 500 ml of
absolute ether. Petroleum ether is added until a second liquid phase
begins to appear and crystallization is allowed to take place." The
dried product weighs 150 to 160 g. The pure substance melts at 88°
to 89° C. The material obtained at this point is sufficiently pure to
be used for most purposes. However, recrystallization can be carried
out by dissolving the product in the minimum amount of warm
alcohol-free chloroform and then adding absolute ether. 1-Bromo-
2,3,4,6-tetraacetyl-o-d-glucose melts at 88° to 89° C and gives
[o]}=-|-197.8° (chloroform, c=2).
NOTES
1 The method as given has been worked out by B. Helferich and E. Günther,
who have modified in some details the original method of E. Fischer and H.
Fischer.
* This material may be prepared by the sodium acetate method given on page 488.
* A 30 to 32 percent solution of hydrogen bromide in glacial acetic acid may be
obtained from chemical-supply dealers.
* The 1-bromo-acetyl derivatives generally decompose readily. Therefore it is
necessary that the extraction be carried out rapidly and that a low temperature
be maintained by adding ice. A large volume of water is desirable in order that
the hydrobromic acid be as dilute as possible.
* The bath temperature should be kept below 45° C.
* The product decomposes fairly readily at room temperature. If it is to be
used for further preparatory work, it should not be separated from the mother
liquor until the day it is needed. Until that time the unfiltered crystals and
mother liquor should be kept at 0° C. The dry crystalline substance may be
kept for a considerable time at 0° C if placed over sodium hydroxide in a desic-
cator and spread in a thin layer.
(2) 1–BROMO-2,3,4,6-TETRAACETYL-o-d-TALOSE.
Method [10].-Ten grams of pentaacetyl-3-d-talose is dissolved in
50 ml of glacial acetic acid containing 38 percent of hydrobromic acid
and 2 ml of acetic anhydride at 0°C. After the acetate has dissolved,
the solution is allowed to stand for several hours at room temperature.
Chloroform (60 ml.) is then added, and the solution is poured into a
mixture of ice and water and extracted several times with chloroform.
The extracts, washed several times with ice water and cold sodium
bicarbonate solution, and dried with anhydrous sodium sulfate, are
evaporated in vacuo to a thin sirup which is taken up with toluene
and again evaporated to a sirup. The sirup is mixed with a small
Polarimetry, Saccharimetry, and the Sugars 501
quantity of dry ether, whereupon crystallization takes place. After
Several hours about 7 g of crystalline 1-bromo-2,3,4,6-tetraacetyl-
o-d-talose separates and from the mother liquors about 0.5 g more
may be obtained. The substance is recrystallized from warm dry
ether. 1-Bromo-2,3,4,6-tetraacetyl-o-d-talose melts at 84°C and
gives [o]}= +165.6° (chloroform, c=4).
(d) PREPARATION OF IODO-DERIVATIVES
(1) 1-IoDO-HEPTAACETYL-4-(8-d-GLUCoSIDO)-o-d-MANNOSE.
Method [11].-Eight grams of octaacetyl-4-3-glucosido-3-d-mannose
is dissolved in 16 ml of dichloromethane in a large Pyrex test tube
and cooled in an ice-and-salt bath. A slow stream of dry hydrogen
iodide is passed through the solution for one-half hour. The solution
is poured into a cold crystallizing dish and evaporated under a glass
jar by means of a rapid current of dry air. The sirup left after eva-
poration is extracted with petroleum ether by stirring and pouring off
the solution. This procedure is repeated several times. Anhydrous
ether is added to the residue, and by rubbing with a glass rod the
sirup may be brought to crystallization. The crystals are washed
with ether. They are recrystallized by dissolving in a small amount
of alcohol-free ethyl acetate and adding ether and finally petroleum
ether until turbidity appears. The substance crystallizes in small
clusters of needles." It melts with decomposition at 140°C and gives
[o]}=-|-111.50° (chloroform, c=2).
NOTE
* The iodo-acetyl sugars are not very stable, but if kept in a thin layer in a
desiccator over sodium hydroxide at 0°C they may be stored for several weeks.
(e) TRANSFORMATION OF THE ACETATE OF ONE SUGAR TO THE
HALOGENO-ACETATE OF ANOTHER SUGAR
(1) ConvKRSION OF OCTAACETYLCELLOBIOSE TO FLUORO-HEXA-
ACETYLGLUCOSIDOMANNOSE, (1-FLUORO-HEXAACETYL-4-(6-d-GLUCOSIDO)-
o-d-MANNOSE). -
Method [11, 12].-Octaacetylcellobiose is fluorinated according to
the method described for the preparation of fluoro-tetraacetylglucose.
In this case, however, 200 g of the cellobiose derivative and 2 kg of
potassium hydrogen fluoride are used. The distillation requires about
2 hours and about 400 g of hydrogen fluoride is obtained. The receiv-
ing vessel containing the octaacetylcellobiose and the hydrogen
fluoride, after standing at room temperature for 5 hours, is cooled in
an ice-and-salt bath and the contents poured into a large separatory
funnel containing water, cracked ice, and chloroform. The chloro-
form extract is dried, concentrated in vacuo, and the chloroform-free
sirup dissolved in methyl alcohol. The mixture solidifies gradually
to a thick mass of white crystals which are separated after standing
overnight. A second crop is obtained from the mother liquors. The
total yield is more than 30 g. The recrystallization of 1-fluoro-
hexaacetyl-4-(3-d-glucosido)-a-d-mannose is easily accomplished from
hot methyl alcohol, from which it separates in small needles on
cooling. The pure compound melts at 145°C (not sharply) and
gives [o]}= +20.8° (chloroform, c=3).
The mother liquor is evaporated in vacuo to a thick sirup from
which 4-glucosidomannose is obtained by acetylating the sirup and
502 Circular of the National Bureau of Standards
crystallizing octaacetyl-4-glucosidomannose from the mixture. The
acetylation is conducted by the zinc chloride method given on page
489. About 35 g of pure octaacetyl-4-(6-d-glucosido)-o-d-mannose
is obtained.
NOTE
| Occasionally an acetylated sugar may be converted to the halogeno-acetate
of another sugar by treatment with a very active halogenating reagent. How-
ever, this type of reaction does not appear to be generally applicable.
(2) CONVERSION OF OCTAACETYLLACTOSE TO CHLoRo-HEPTAACE-
TY L N E O L A CTO SE, (1-CHLORO-HEPTAACETYL-4-(6-d-GALACTOSIDO)-d-
ALTROSE).
Method [13, 14].—One hundred grams of powdered anhydrous
aluminum chloride and 50 g of phosphorus pentachloride are added
to 50 g of octaacetyllactose dissolved in 350 ml of alcohol-free anhy-
drous chloroform in a 2-liter flask. The mixture is shaken for a
minute or two, the flask is connected with a reflux condenser, and the
contents are heated to gentle boiling for 20 minutes. The mixture is
cooled and the chloroform layer is poured into 5 liters of ice and
water. The residue is also carefully decomposed with ice water and
the aqueous solution is extracted with chloroform. The combined
chloroform extracts are washed with ice water, dried with calcium
chloride, and concentrated in vacuo to a thick sirup. This is taken
up in 400 ml. of dry ether and allowed to stand for several days in
the refrigerator for crystallization to take place. The crystals, which
consist of 1-chloro-heptaacetyllactose and 1-chloro-heptaacetylneo-
lactose, are collected on a filter and washed with dry ether. The
crystals are then trituated with 100 ml of cold ethyl acetate. The
chloro-heptaacetyllactose goes into solution and leaves a residue of
crude chloro-heptaacetylneolactose. This is recrystallized by dissolv-
ing it in a small quantity of chloroform and adding several volumes of
ether. The yield is about 16 to 22 g. 1-Chloro-heptaacetylneolac-
tose melts at 182°C and gives [o]}= +71.2° (chloroform, c = 1).
1-Chloroheptaacetyllactose (melting point, 120°C) is recovered from
the ethyl acetate extract.
(f) REFERENCES
. Fischer and R. Oetker, Ber. deut. chem. Ges. 46, 4035 (1913).
. Micheel and H. Micheel, Ber. deut. chem. Ges. 63, 386 (1930).
H. Brauns, J. Am. Chem. Soc. 51, 1820 (1929).
H. Brauns, J. Am. Chem. Soc. 45, 833 (1923).
. Ruff and W. Plato, Ber. deut. chem. Ges. 37, 673 (1904).
PacSu, Ber. deut. chem. Ges. 61, 1508 (1928).
. H. Brauns, J. Am. Chem. Soc. 44, 404 (1922).
. Fischer and H. Fischer, Ber. deut. chem. Ges. 43, 2534 (1910).
. Ohle, W. Marecek, and W. Bourjau, Ber. deut. chem. Ges. 62, 849 (1929).
[ W. W. Pigman and H. S. Isbell, J. Research NBS 19, 210 (1937) RP1021.
[11] D. H. Brauns, J. Am. Chem. Soc. 48, 2776 (1926).
[12] H. S. Isbell, BS J Research 5, 1185 (1930) RP253.
[13] A. Kunz and C. S. Hudson, J. Am. Chem. Soc. 48, 1978 (1926).
[14] N. K. Richtmyer and C. S. Hudson, J. Am. Chem. Soc. 57, 1718 (1935).
4. BENZOYL DERIVATIVES
General characteristics.-The benzoyl derivatives of the sugars were
first prepared by application of the Schotten-Baumann reaction,
using sodium hydroxide and benzoyl chloride, but it is difficult to
Polarimetry, Saccharimetry, and the Sugars 503
produce complete benzoylation by this method. By using quinoline,
or better, pyridine and benzoyl chloride, complete benzoylation is
obtained. By this method o-d-glucose gives the pentabenzoyl-o-d-
glucose, and 3-d-glucose gives the beta isomer. Fructose gives
tetrabenzoyl furanose and pyranose derivatives as well as the open-
chain pentabenzoyl-keto-fructose [1, 2].
(a) PREPARATION OF BENZOYL DERIVATIVES WITH BENZOYL CHLORIDE IN
PYRIDINE SOLUTION
(1) PENTABENZOYL-d-GLUCOSE.
Method [3].--Dried anhydrous dextrose (10 g) is added to a cold
solution of 35 ml of benzoyl chloride, 42 ml of dry pyridine, and 70 ml
of dry chloroform." The reaction is controlled by cooling the mixture
in an ice-salt bath. When the sugar is all dissolved, the solution is
allowed to stand for 18 hours at 0°C. A large quantity of chloroform
is then added and the chloroform layer is washed successively in a
separatory funnel with ice-cold dilute sulfuric acid, sodium bicar-
bonate, and water. It is then dried with sodium sulfate and evap-
orated in vacuo to a thick sirup which is reevaporated several more
times with alcohol. The residue is taken up with alcohol containing
10 percent of pyridine and allowed to crystallize. Pure pentabenzoyl-
o-d-glucose melts at 187° C* and gives [o]}= + 138.5° (chloroform).
The beta isomer is prepared in a similar way from beta glucose.
In this case, however, the reaction, being less vigorous, is allowed to
take place at 15°C and crystalline material settles out of the reaction
mixture after several hours. From 50 g of 3-d-glucose 120 g of the
pentabenzoyl-3-d-glucose is obtained which, when pure, melts at
157° Cº and gives [o]}= +24° (chloroform).
NOTES
* The solution is prepared by cooling each reagent to -10°C, dissolving the ben-
zoyl chloride in an equal volume of chloroform, and adding this to a solution of
the pyridine in 35 ml of chloroform.
* Levene and Meyer recrystallized the material, first from ethyl alcohol con-
taining 5 percent of pyridine and then from pure alcohol.
* A considerable number of recrystallizations from chloroform and ethyl acetate
are necessary in Order to obtain pure material.
(b) REFERENCES
[1] P. Brigl and R. Schinle, Ber. deut. chem. Ges. 66, 325 (1933).
[2] P. Brigl and R. Schinle, Ber. deut. chem. Ges. 67, 127 (1934).
[3] P. A. Levene and G. M. Meyer, J. Biol. Chem. 76, 513 (1928).
5. CARBONATE DERIVATIVES
General characteristics.—The sugar carbonates are well-defined and
easily isolated products which are similar to the acetone sugars in
many respects. The carbonate group may be removed by alkaline
hydrolysis without disturbing acetone or glycosidic groups. On the
other hand, the carbonyl group is more resistant to acid hydrolysis
than the acetone group [1]. These properties make the carbonates
useful intermediates for the production of other derivatives. The
methods of preparation and properties are illustrated by the examples
which follow.
504 Circular of the National Bureau of Standards
(a) PREPARATION OF CARBONATES WITH CARBONYL CHLORIDE IN PYRIDINE
SOLUTION
(1) 2,3-5,6-d-MANNOSE DICARBONATE.
Method [1].-Six grams of d-mannose is dissolved in 20 ml of
pyridine, and the solution is vigorously stirred in an ice bath while a
fairly rapid current of carbonyl chloride is passed into it. After about
45 minutes, ice water is added and the amorphous carbonate which
separates is discarded. The clear solution is neutralized with an
excess of barium carbonate and evaporated to a small volume under
diminished pressure to remove the pyridine. The resulting solution
is filtered and extracted many times with ethyl acetate. On evapora-
tion the ethyl acetate extract gives about 0.5 g of d-mannose dicarbon-
ate which is recrystallized from water. The substance melts at 122°
to 123°C, and gives [o];s= +26° (acetone, c= 1).
(b) PREPARATION OF CARBONATES WITH CARBONYL CHLORIDE IN ACETONE
SOLUTION
(1) MonoACETONE-d-GLUCOSE MONOCARBONATE
Method [2].-Gaseous carbonyl chloride is introduced into a sus-
pension of glucose (8 g) in dry acetone (70 ml) under vigorous
mechanical stirring until all the glucose has dissolved (3 hours).
After being kept overnight, the solution is neutralized by agitation
with basic lead carbonate, and filtered, and the residue washed with
acetone. The combined filtrate and washings are evaporated nearly
to dryness at 35°C and the resulting crystalline monoacetone-d-
glucose monocarbonate is separated (about 3 g). The product
recrystallized from ethyl alcohol sinters at 215°C and melts with
decomposition and effervescence at 223° to 224° C. Monoacetone-
d-glucose monocarbonate shows ſoft's=–36°. The mother liquors
yield considerable monoacetoneglucose and diacetoneglucose.
(c) REMOVAL OF THE CARBONATE GROUPS
(1) METHYL cº-d-MANNoFURANOSIDE FROM METHYL 2,3-5,6-o-d-
MANNOSIDE DICARBONATE.
Method [1].-The dicarbonate of methyl o-d-mannofuranoside
dissolved in a little acetone is warmed gently with an excess of barium
hydroxide solution. Barium carbonate is precipitated and after
removal of the excess barium hydroxide by means of carbon dioxide
treatment, and filtration, the filtrate is evaporated at 45° C; the
residue is extracted with ethyl acetate or methyl alcohol. Evapora-
tion of the extract gives crystalline methyl cº-d-mannofuranoside in
95 percent of the theoretical yield. The product is recrystallized
from methyl alcohol containing ether. Methyl o-d-mannofuranoside
forms colorless needle-like crystals which melt at 118° to 119°C and
give [o]}=-|-113° (water, c=1).
(2) ETHYL 3-d-GLUCOFURANOSIDE.
Method [2].-Ethyl-5, 6-3-d-glucofuranoside monocarbonate is dis-
solved in an equivalent quantity of 0.25 N sodium hydroxide (2 moles
of alkali for each mole of the compound). After standing for several
hours in the refrigerator, the solution is evaporated to dryness under
diminished pressure at 35° C and the residue extracted several times
with ethyl acetate. The residue obtained from evaporation of the
ethyl acetate solution crystallizes when kept in a vacuum desiccator
Polarimetry, Saccharimetry, and the Sugars 505
containing phosphoric oxide. It is very hygroscopic. The recrystal-
lization is effected by dissolving the crystals in dry ethyl acetate
containing a trace of ethyl alcohol, and then adding dry ether until a
slight turbidity appears. The solution is kept for several days at
– 10° C, and the large clusters of crystals which then accumulate
(yield, 85 to 90 percent) are washed with dry ethyl acetate, drained on
porous tile, and kept over phosphoric oxide in a vacuum. Ethyl-6-d-
glucofuranoside melts at 59° to 60° C and gives [o]}=–86° (water,
c=1). (d) REFERENCES
[1] W. N. Haworth and C. R. Porter, J. Chem. Soc. 1930, 151, 649.
[2] W. N. Haworth and C. R. Porter, J. Chem. Soc. 1929, 2796.
6. p-TOLUENESULFONYL DERIVATIVES
General characteristics.--Condensation products of the sugar with
p-toluenesulfonyl chloride are made by treating the sugar or sugar
derivative with p-toluenesulfonyl chloride in the presence of pyridine
or alkali. The p-toluenesulfonyl (tosyl) group so introduced is stable
to weak acids and to the conditions required for acetylation, benzoy-
lation, and methylation. Tosyl groups may be replaced, however,
with hydroxyls by reduction with sodium amalgam. The tosyl
group can be replaced by treatment with sodium methylate; this
results in an anhydro sugar formed with Walden inversion. The
anhydro derivatives are readily hydrolyzed and thus provide a means
for the preparation of hitherto rare and inaccessible sugars [1]. A
discussion of the Walden inversion and the steric factors which
influence the formation and cleavage of the anhydro derivatives
was given by Isbell [2]. A tosyl group on the terminal carbon may
be replaced with iodine by treating the tosyl compound in acetone
solution with sodium iodide. A nitrate group may be quantitatively
substituted for the iodine atom and in turn a hydroxyl group may
be substituted for the nitrate group [3]. This procedure provides a
method for the identification and estimation of primary alcoholic
groups and for the preparation of sugar derivatives with unsub-
stituted primary alcoholic groups. The pentose mercaptals react
with one equivalent of p-toluenesulfonyl chloride to give pentose
tosyl mercaptals. Since the hydroxyl on carbon 5 is blocked, these
compounds readily yield furanose derivatives.
(a) PREPARATION OF TOSYL DERIVATIVES WITH p-TOLUENESULFONYL CHLORIDE
IN PYRIDINE SOLUTION
(1) 5-TOSYL-MONOACETONE-3–l-RHAMNOSE.
Method [4].-Monoacetone-8-l-rhamnose (5 g) is dissolved in 25 ml
of dry pyridine, and 4.81 g (1.1 moles) of p-toluenesulfonyl chloride
is dissolved in 10 ml of dry alcohol-free chloroform, and the two
solutions are mixed at 0°C. The solution is kept in an ice bath for
about 1 hour and then at room temperature for 12 hours more.
Water (1 ml) is then added and the mixture is thoroughly shaken
and allowed to stand for 30 minutes. More chloroform is added and
the chloroform layer is washed at 0° C twice each with water, 10-
percent sulfuric acid, saturated sodium bicarbonate, and finally
again with water. The extract, after drying with calcium chloride,
is evaporated under reduced pressure to a thick sirup which is re-
506 Circular of the National Bureau of Standards
evaporated with toluene. The residue is dissolved in toluene and
petroleum ether is added to saturation. Crystallization takes place
readily and about 3.5 g of material is obtained. The pure 5-tosyl-
monoacetone-8-l-rhamnose melts at 92° to 93° C and gives
[o]}= +29.1° (chloroform).
(b) REFERENCES
[1] T). S. Mathers and G. J. Robertson, J. Chem. Soc. 1933, 1077.
[2] H. S. Isbell, Ann. Rev. Biochem. 9, 66 (1940).
[3] J. W. Oldham and J. K. Rutherford, J. Am. Chem. Soc. 54, 366 (1932).
[4] P. A. Levene and J. Compton, J. Biol. Chem. 116, 169 (1936).
7. METHYL ETHERS
General methods.-The stability of methyl ethers of the sugars in
the presence of acid or alkali has made them very useful in structural
studies. Purdie and Irvine [1] first employed silver oxide and methyl
iodide as methylating agents for sugars. Aldehyde and ketone groups
are oxidized by silver oxide, and hence it is necessary to convert reduc-
ing sugars into glycosides before methylating with these reagents.
Three or four treatments with the reagents are frequently necessary
for complete methylation.
Haworth [2] in 1915 used dimethyl sulfate and 30-percent aqueous
Sodium hydroxide. These reagents are less expensive than those used
previously and are better adapted to the first stages of the methylation
because of the solubility of the sugars and glycosides in aqueous
solution. -
Sodium and potassium salts have been used as intermediates in
the preparation of methyl derivatives of carbohydrates. Freudenburg
and Hixon [3] prepared 3-methyl-diacetone-d-fructose in 85- to
90-percent yield by first making the sodium salt of diacetonefructose
in benzene solution and treating this salt with methyl iodide.
Fear and Menzies [4] prepared the trithallium salt of methyl
o-d-glucoside by means of thallous hydroxide. This salt when re-
fluxed with methyl iodide gave methyl trimethyl-o-d-glucoside [5].
In the presence of excess thallous hydroxide the methyl tetramethyl
o-d-glucoside was formed.
Muskat [6] described a method for methylating sugars in which he
prepared their potassium, sodium, or lithium salts in liquid ammonia
(–33.4° C) and allowed this salt to react with methyl iodide. By this
method the complete methylation or partial methylation is obtained
in One step, depending upon the number of metallic atoms introduced.
A special apparatus is required, since it is necessary to maintain
anhydrous conditions at low temperatures.
(a) METHYLATION WITH METHYL IODIDE AND SILVER OXIDE
(1) METHYL 2,3,4,6-TETRAMETHYL-o-d-GALACTOSIDE.
Method [7].-Nineteen grams (0.1 mole) of methyl ox-d-galactoside
and 142 g (1 mole) of methyl iodide are placed in a three-necked flask
equipped with a mercury-sealed mechanical stirrer and a condenser
through which ice water is circulated, and sufficient hot methyl
alcohol is added to dissolve the galactoside. The flask is heated in a
water bath at 45° C so as to keep the methyl iodide gently refluxing,
and in 10 equal portions at 94-hour intervals there is added 116 g
Polarimetry, Saccharimetry, and the Sugars 507
(0.5 mole) of silver oxide." The heating is continued for 1 hour after
the final addition of silver oxide. The reaction mixture is extracted
with boiling absolute methyl alcohol and the solvent removed by
means of vacuum distillation, the temperature finally being raised to
100° C in order to remove all traces of water.
The sirup thus obtained is dissolved in an equal weight of absolute
methyl alcohol and the methylation repeated. The reaction product is
extracted with ether and the solvent removed by means of vacuum
distillation as before. -
A third methylation is carried out, and since the partially methylated
galactoside is soluble in methyl iodide, the methyl alcohol is omitted,
but the same amounts of methyl iodide and silver oxide are used.
The reaction mixture is extracted with ether and the final product
distilled. The distillate, which boils at 136° to 137° C at 11 mm, is
collected in one fraction. A higher boiling fraction upon remethylation
also gives the methyl tetramethylgalactoside. The total yield is
about 60 percent of the theoretical. Methyl 2,3,4,6-tetramethyl-o-d-
galactoside gives [o]}= + 143.4° (water, c=10) and has a specific
gravity of 1.107.
NOTE
1 The silver oxide should be freshly prepared and finely divided. C. B. Young
in a monograph, A General Review of Purdie's Reaction, gives the following
procedure for its preparation [8]. A hot filtered barium hydroxide solution (100 g
of Ba(OH)2.8H2O in 1 liter of water) is added to a hot solution of silver nitrate
(100 g of silver nitrate in 500 ml of water), and the precipitated silver oxide washed
with boiling water until all excess barium hydroxide has been removed. The
filtered product is dried, first on a porous plate and afterwards in an Open steam
oven. The oxide is powdered to facilitate drying and is kept in a desiccator until
required for use.
(b) METHYLATION WITH DIMETHYL SULFATE AND SODIUM HYDROXIDE
(1) HEPTAMETHYLSUCROSE.
Method [2].-Sucrose (20 g) is dissolved in 10 ml of water contained
in a 1-liter three-necked flask fitted with two dropping funnels, a water
condenser, and a mechanical stirrer. The flask is placed in a water
bath maintained at 70° C. During 1 hour 120 ml of dimethyl sulfate
and 320 ml of 30-percent sodium hydroxide are added in such a way
that the solution is always alkaline. The bath temperature is raised
to 100° C and the reaction mixture heated for 1 hour in order to de-
compose the unreacted dimethyl sulfate. The solution is then cooled
and extracted with chloroform. The chloroform is evaporated and
the heptamethyl sucrose distilled under reduced pressure. About 15 g
of heptamethyl sucrose is obtained as a colorless viscous sirup which
gives a boiling point of 191° to 195°C at 0.18 mm pressure, and [o]}=
+68.5° (methyl alcohol, c=6).
(c) PREPARATION OF METHYL ETHERS FROM THE ACETATES
Dimethyl sulfate and aqueous sodium hydroxide in acetone solution
may be used to prepare methyl derivatives from sugar acetates. The
acetyl groups are completely replaced by methyl groups during one
treatment with the methylating reagents. Compounds of high mole-
cular weight that are difficult to methylate directly because of their
insolubility are conveniently methylated by this method.
508 Circular of the National Bureau of Standards
(1) TRIMETHYLINULIN.
Method [9].-Twelve grams of inulin acetate and 250 ml of acetone
are placed in a 2-liter flask equipped with a mechanical stirrer. The
temperature is kept at 55°C and 120 ml of dimethyl sulfate and 320 ml
of 30-percent aqueous sodium hydroxide are added in portions of 12 ml
and 32 ml, respectively, at 10-minute intervals. Acetone is added
from time to time in such amount that the volume of the reaction
mixture is 300 ml or more. An emulsion forms after the second or
third addition of reagents. Immediately following the addition of the
final portion of dimethyl sulfate and sodium hydroxide, 100 ml of water
is added and the temperature raised to 75°C for a period of 15 minutes
in order to remove the bulk of the acetone. Trimethylinulin separates
as pellets or as a fine porous solid, its nature depending upon the rate
of stirring. The mixture is poured into a large volume of water with
rapid stirring, and the methylated inulin is collected on a filter and
washed with hot water. The air-dried product is dissolved in boiling
alcohol; on cooling, trimethylinulin separates as a white amorphous
solid. The crude substance is purified by dissolving it in a mixture of
equal volumes of chloroform and acetone and precipitating the
product by the addition of petroleum ether. The yield is 95 percent of
the theoretical. Trimethylinulin melts at 140° C and gives [o]}=
—55° (chloroform, c = 1).
(d) METHYLATION WITH METHYL IODIDE AND A SODIUM SALT IN EENZENE OR
ETHER SOLUTION
(1) 3-METHYL-DIACETONE-d-FRUCTOSE.
Method [3].-Ten grams of 1, 2–4, 5-diacetonefructose and 50 ml of
benzene are placed in a 100-ml pressure flask, and under anhydrous
conditions an excess of sodium is added in small portions. After 3 to
4 hours, when the evolution of hydrogen is complete, the excess sodium
is removed with a glass rod. The solution is reduced to a sirupy
consistency by evaporation under diminished pressure, after which 11 g
(2 moles) of methyl iodide is added and the mixture is allowed to
stand for 24 to 28 hours at 30° to 40°C. The material is then diluted
with ether, and the sodium iodide which precipitates is separated by
filtration and washed with ether. 3-Methyl-diacetone-d-fructose crystal-
lizes from the ether solution. The crystals are collected on a filter
and washed with a little water to remove the unmethylated diacetone-
fructose. The crude material is recrystallized from petroleum ether.
A yield of 85 to 90 percent of the pure product melting at 115° C is
thus obtained.
In the preparation of the corresponding methyl derivatives of
glucose, galactose, and mannose by this procedure, 30 ml of dry ether
is used as solvent in place of the 50 ml of benzene.
(e) METHYLATION WITH THALLOUS HYDROXIDE AND METHYL IODIDE
(1) METHYLATION OF METHYL cº-d-GLUCOPYRANoSIDE.
Method [5].-Twelve hundred ml of 1.33 N thallous hydroxide is
evaporated to a volume of 400 ml and while hot is poured into a solution
of 38 g of methyl a-d-glucoside dissolved in 18 ml of water. The
precipitate is filtered and dried over phosphorus pentoxide in a
vacuum desiccator protected from light. Seven days are required for
the drying. The dry powder (about 240 g) is heated 6 hours under a
reflux condenser with 115 ml of methyl iodide. The excess methyl
Polarimetry, Saccharimetry, and the Sugars 509
iodide is evaporated and the residue is extracted with chloroform. The
chloroform solution is concentrated to a sirup and fractionally distilled
under reduced pressure. Barker, Hirst, and Jones [5] report three frac-
tions: (1) Methyl tetramethyl-o-d-glucoside (6.2 g), boiling point
125°C at 0.01-mm pressure, nº = 1.4450. On hydrolysis with 8-percent
hydrochloric acid at 95°C this gave nearly quantitatively tetramethyl
glucopyranose, melting point 87°C. (2) A mixture of methyl tetra-
methyl-o-d-glucoside and methyl trimethyl-o-d-glucoside (4.7 g),
boiling point 135°C at 0.01-mm pressure, nº-1.4522. (3) Methyl
trimethyl-o-d-glucoside (17.5 g), boiling point 140° to 143°C at 0.01-
mm pressure m”= 1.4572.
(f) QUANTITATIVE DETERMINATION OF METHOXYL GROUPS
The Zeisel method [10] for the determination of alkoxyl groups con-
sists in treating an ether with boiling hydrogen iodide, whereby the
following reaction takes place:
R’OR+HI->R/OH-HRI. The volatile iodide is collected in an alco-
holic silver nitrate solution as AgI.2AgNO3. When treated with
3 4.
FIGURE 112.-Apparatus for the gravimetric determination of methoxyl groups.
water this double salt decomposes, yielding silver iodide, which is
determined gravimetrically.
When sulfur is present, it is necessary to substitute pyridine for the
alcoholic silver nitrate and to evaporate the pyridine solution to dry-
ness before precipitating the iodide as the silver salt. If the compound
contains an alkyl group attached to nitrogen, the N-alkyl group may be
partially converted to the alkyl iodide. Also, in the presence of
hydrogen iodide an alkyl group may be transferred from an oxygen
to a nitrogen atom.
(1) GRAVIMETRIC METHOD [10].
Reagents.-Hydrogen iodide: Density, 1.7; boiling point, 125° to
127°C; 57-percent solution. Silver nitrate solution: About 4 g of silver
nitrate is dissolved in 10 ml of water and mixed with 90 ml of absolute
alcohol. The solution is kept in the dark; and before use, it is
filtered through a dry filter paper and acidified with nitric acid.
Red phosphorus: The reagent grade of red phosphorus is digested
one-half hour with dilute ammonia, washed with hot water, and stored
under water.
323414°–42—-–34

510 Circular of the National Bureau of Standards
Procedure.—About 15 ml of hydrogen iodide, a boiling stone, and a
trace of red phosphorus are placed in the 50-ml round-bottom flask
(1) of figure 112. The flask is equipped with an inlet tube for admit-
ting carbon dioxide, and with either an air-cooled or a water-jacketed
reflux condenser held at 40° to 60°C and connected with a scrubber
(2) containing a little warm water and 0.5 g of red phosphorus. This
scrubber, or flask, is connected with absorption bottles (3) and (4),
which contain, respectively, 20 ml and 10 ml of alcoholic silver nitrate.
Before the analysis is started, a blank test is run by refluxing the hy-
drogen iodide while a stream of carbon dioxide is passed through the
apparatus. There should be no turbidity in the silver nitrate solution
during an interval of 10 minutes. After the blank test has been made,
flask (1) is cooled and a 0.3 to 0.4–g sample of the material to be
analyzed is introduced. The hydrogen iodide is warmed slightly
and refluxed in the presence of a stream of carbon dioxide. In about
10 minutes a white precipitate of AgI.2AgNO3 begins to form in the
first silver nitrate container. Upon completion of the reaction, which
usually requires about 40 minutes, the silver nitrate solutions are
combined, diluted with several volumes of water, acidified with nitric
acid, and boiled gently for several minutes. The silver iodide is then
determined gravimetrically. AgIX0.1322=OCH3.
(2) VolumETRIC METHOD [11, 12, 13].-The alkyl halide is collected
in an acetic acid solution of potassium acetate and bromine. This
method, which can be used for substances containing sulfur, requires
less time and a smaller sample than the gravimetric method. The
following reactions take place in the bromine solution:
CHAI+Br2->CH3Br—HIBr.
IBr-H2Brz–H3H2O->HIO3 +5.HBr.
The solution is washed into a flask containing aqueous sodium acetate,
the excess bromine is removed with formic acid, potassium iodide is
added, the solution acidified with sulfuric acid, and the liberated
iodine titrated with 0.1 N thiosulfate. Each methoxyl group liberates
six atoms of iodine; hence 1 ml of 0.1 N thiosulfate represents 0.5172
mg of methoxyl. Thus for a 10-ml titration 10 to 40 mg of a methyl
sugar is sufficient.
Reagents.—Hydrogen iodide: Hydrogen iodide free from iodine may
be obtained by treating constant-boiling hydrogen iodide at approxi-
mately 100°C with slightly more than the necessary quantity of 50–
percent hypophosphorous acid. When the hydrogen iodide is thus
treated, no free iodine is evolved and hence no red phosphorus is
necessary in the scrubber, B. (fig. 113). Potassium acetate: 10-
percent solution of potassium acetate in acetic acid. Sodium acetate:
25-percent solution. Sodium thiosulfate: 0.1 N solution.
Procedure.—A 10- to 40-mg sample of the material to be analyzed
is introduced into the reaction flask, A, in which 5 ml of hydrogen
iodide and 2.5 ml of melted analytical phenol have been placed.
If a solid, the sample may be weighed on a piece of cigarette paper;
if a liquid, it may be weighed and added in a small glass container.
The flask is connected to the rest of the apparatus, which consists of
a scrubber, B, containing a little water, and two receiving flasks,
C and D. The receiving flasks contain 10 ml of a 10-percent solution
of potassium acetate in acetic acid to which 6 drops of bromine have
been added, about 6 ml in the first and 4 ml in the second flask. A
Polarimetry, Saccharimetry, and the Sugars 511
slow uniform stream of carbon dioxide is passed through the apparatus
and the reaction flask is gently heated until the liquid refluxes halfway
up the condenser. Ordinarily 30 to 45 minutes are required to com-
plete the reaction and sweep out the apparatus. After the reaction
is complete, the contents of the 2 receivers are washed into a 250-ml
Erlenmeyer flask containing 5 ml of a 25-percent aqueous sodium
acetate solution. The volume of the solution is adjusted to about
125 ml and 6 drops of 90-percent formic acid is added. Then the
flask is rotated until the color due to bromine disappears, whereupon
12 more drops of formic acid is
added. The mixture is allowed to
stand 2 minutes, 1 g of potassium
iodide and a few milliliters of
10-percent sulfuric acid are added,
and after 3 minutes the liberated
iodine is titrated with 0.1 N sodi-
um thiosulfate.
A blank should be run on the
reagents, as all phenol appears to
contain some substance which
gives a small blank. This value is
to be subtracted only from the
first determination made with a
given charge, as the material re-
sponsible for the blank is destroyed
with the first determination. If
the carbon dioxide is introduced
above the surface of the hydrogen Figure 1 13—Apparatus for the volumetric
iodide-phenol charge, bumping determination of methoxyl groups.
may be prevented by introducing
a capillary boiling tube. Each methoxyl group liberates six atoms
of iodine, and hence requires 6 moles of thiosulfate.
ml O.1 N thiosulfate.9.5172×100 percentage of OCHA
mg Sample
(g) REFERENCES
[1] T. Purdie and J. C. Irvine, J. Chem. Soc. 83, 1021 (1903).
[2] W. N. Haworth, J. Chem. Soc. 107, 8 (1915).
3] K. Freudenburg and R. M. Hixon, Ber. deut. chem. Ges. 56, 2125 (1923).
4] C. M. Fear and R. C. Menzies, J. Chem. Soc. 1926, 937.
5] C. C. Barker, E. L. Hirst, J. K. N. Jones, J. Chem. Soc. 1938, 1695.
[6] I. E. Muskat, J. Am. Chem. Soc. 56, 693, 2449 (1934).
§ J. C. Irvine and A. Cameron, J. Chem. Soc. 85, 1071 (1904).
8
9
0
C. B. Young, A General Review of Purdie's Reaction, Memorial Volume of
Scientific Papers of St. Andrews University 500th Anniversary.
W. N. Haworth and H. R. L. Streight, Helv. Chim. Acta 15, 614 (1932).
Hans Meyer, Lehrbuch der Organisch-Chemischen Methodik, I, 891 (Julius
Springer, Berlin, 1922).
[11] Franz Wiebóck and Adolf Schwappach, Ber. deut. chem. Ges. 63,2818 (1930).
[12] E. P. Clark, J. Assn. Official Agr. Chem. 15, 136 (1932).
[13] E. P. Clark, J. Am. Chem. Soc. 51, 4180 (1929).
8. TRIPHENYLMETHYL ETHERS
General characteristics.-Triphenylmethyl chloride reacts with
sugars and glycosides in the presence of pyridine to give triphenyl-
methyl ethers, which are called “trityl” derivatives. It has been

512 Circular of the National Bureau of Standards
shown that triphenylmethyl chloride condenses, preferably with the
primary alcohol group. However, under more severe conditions
secondary alcoholic groups will react [1]. Since the trityl derivatives
are stable under the conditions required for acetylation and benzoyla-
tion, and since the trityl group may be removed easily by mild acid
treatment, these compounds have proved useful for the production
of sugar derivatives containing free primary hydroxyl groups [2].
The trityl group may also be replaced directly by bromine or iodine
atoms [3].
(a) PREPARATION OF TRITYL DERIVATIVES
(1) METHYL 6-TRITYL-o-d-GLYcopyRANOSIDE.
Method [4].-One part of dry methyl o-d-glucoside and 1.4 parts of
triphenylchloromethane (equivalent proportions) are dissolved in 8
parts of pure dry pyridine." The solution is heated on a boiling-water
bath for 1 hour” and then is allowed to cool. Water is added drop-
wise until the point of turbidity is reached, and the solution is allowed
to stand for an hour. The solution is then poured into ice water.
The sirupy layer is separated and rubbed up repeatedly with fresh
portions of water. Crystallization takes place slowly. About 1.5
parts of the trityl derivative are obtained. The crude product is
recrystallized from 5 parts of alcohol. When air-dried the compound
contains 1.5 moles of alcohol of crystallization and melts at 80° C if
heated rapidly. Methyl 6-trityl-o-d-glucopyranoside, when alcohol-
free, melts at 151° to 152°C and gives [o]}= +86.3° (pyridine).
NOTES
1 Traces of water will inhibit this reaction markedly.
* Or allowed to stand 24 hours at room temperature. For those glycosides
without a primary alcohol group a considerably longer time is required (14 days
at room temperature).
(b) REMOVAL OF TRITYL GROUPS
(1) ConvKRSION OF METHYL 2,3,4-TRIBENZOYL-6-TRITYL-o-d-GLU-
cosid E. To METHYL 2,3,4-TRIBENZOYL-o-d-GLUCOSIDE.
Method [4].-Two parts of methyl 2,3,4-tribenzoyl-6-trityl-o-d-
glucoside are dissolved in 2.5 parts (by volume) of chloroform. The
solution is cooled in an ice bath and is rapidly saturated with dry
hydrogen chloride. After 30 minutes an excess of a saturated aqueous
solution of potassium bicarbonate is mixed with the ice-cold solution.
The chloroform layer is washed with water, dried with calcium chloride
and evaporated in vacuo to a sirup which is taken up with a small
amount of methyl alcohol. Upon standing at 0°C the solution deposits
crystals of triphenylcarbinol and triphenylmethyl methyl ether. The
crystals are separated and the mother liquor is evaporated again in
vacuo to a thick sirup, which is dissolved in 1.5 parts (by volume) of
hot absolute alcohol. Methyl tribenzoyl-o-d-glucoside crystallizes
from the alcoholic solution in a yield of about 65 per cent and gives
[o]}= +131.7° (pyridine).
(c) QUANTITATIVE DETERMINATION OF TRITYL GROUPS
The trityl groups in a compound can be determined by their con-
version to triphenylcarbinol. A weighed sample which will yield
Polarimetry, Saccharimetry, and the Sugars 513
approximately 100 mg of triphenylcarbinol is dissolved with careful
trituration in 2 ml of sulfuric acid (sp gr 1.84). This solution is
poured quickly into 50 ml of distilled water and allowed to stand for
30 minutes. The triphenylcarbinol is collected on a weighed Gooch
crucible, washed with distilled water, and dried at 110°C to constant
weight. The results can be expressed as triphenylcarbinol, or as
percentage of triphenylmethyl groups according to the formula:
Wt of triphenylcarbinol)(0.9347X 100

Wt of sample = percentage of C(C6H5)3
(d) REFERENCES
[1] E. L. Jackson, R. C. Hockett, and C. S. Hudson, J. Am. Chem. Soc. 56, 947
(1934).
[2] D. D. Reynolds and W. L. Evans, J. Am. Chem. Soc. 60, 2559 (1938).
[3] M. L. Wolfrom, J. L. Quinn, and C. Christman, J. Am. Chem. Soc. 57, 713
(1935).
[4] B. Helferich and J. Becker, Liebigs Ann. Chem. 440, 1 (1924).
9. GLY COSIDIC DERIVATIVES
(a) PREPARATION OF GLYCOSIDES BY FISCHER METHOD [1]
General characteristics of the method.—By treating dry methyl al-
coholic solutions of the sugars with hydrogen chloride, the hydroxyl
of the reducing carbon is replaced by a methoxyl group and an equi-
librium is established between the alpha and beta methyl pyranosides
and furanosides [2]. When other alcohols—such as ethyl, propyl,
amyl, isopropyl, allyl, and benzyl—are used as solvents, the cor-
responding glycosides are formed. The pyranose modifications usually
predominate in the equilibrium mixture; the furanose modifications
are at their maximum during the early stages of the reaction. In the
preparation of furanose and pyranose glycosides advantage is taken
of these properties [3]. The furanosides are prepared by allowing the
reaction to proceed, usually at room temperature, until the furanoside
content reaches a maximum; the pyranosides are prepared by heating
the alcoholic solution until equilibrium is reached. The time required
for reaching the desired state varies for the different sugars.
Since the equilibrium mixture contains the alpha and beta pyranose
and furanose modifications, it is often difficult to obtain crystalline
products. The following methods are useful for the purification of
glycosides:
(a) Acetylation of the crude glycoside mixture gives products which
frequently can be separated in the crystalline state.
(b) Calcium chloride and other molecular compounds are occasion-
ally useful for separating the isomeric glycosides [4, 5, 6, 7].
(c) Mixtures of the acetylated alpha and beta glycosides in chloro-
form solution are converted by titanium tetrachloride to mixtures in
which the alpha isomer predominates [8].
(d) For some glycosides the selective action of enzymes may be
used to remove one of the isomers from the crude mixture. By using
the proper enzyme [9] (o-glucosidase or 3-glucosidase, or the cor-
responding enzymes for other sugars) the alpha or beta methyl
glycoside may be removed from a mixture of the two. This method
has been successfully employed for the separation of the methyl
fructosides [10].
514 Circular of the National Bureau of Standards
(e) Since the methyl furanosides and their acetates can be distilled
at a low pressure, distillation may be used to separate them from the
less volatile pyranosides [2].
The Fischer method using methyl alcoholic hydrogen chloride is
particularly suitable for preparing the methyl pyranosides. It is
usually not applicable to disaccharides as hydrolysis occurs simul-
taneously with glycoside formation. When the sugar is insoluble in
the alcohol, the method may be applied to an alcoholic solution of
the halogeno-acetyl or the acetyl sugar. In this case, deacetylation
and glycoside formation proceed simultaneously.
(1) METHYL l-ARABINOPYRANoSIDEs.
Method.—[11].-One hundred grams of l-arabinose is refluxed for
3 hours with 1 liter of anhydrous methyl alcohol containing 1.5 percent
of hydrogen chloride. The acid is neutralized with silver carbonate'
and the solution is filtered, treated with activated charcoal, and re-
filtered. The filtrate is evaporated in vacuo to a thin sirup, which is
allowed to crystallize. About 30 g of crude methyl 3-l-arabinoside is
obtained which is purified by an extraction with hot ethyl acetate.
The residue is recrystallized from absolute ethyl alcohol. A second
extraction and recrystallization give pure methyl 3-l-arabinopyrano-
side, which melts at 169° C and gives [o]}= +245.5° (water, c=7).
The mother liquor from the beta arabinoside preparation is evapo-
rated under reduced pressure to a thin sirup which, after standing in
a vacum desiccator, crystallizes slowly. The crystalline material,
which is a mixture of the alpha and beta isomers, is separated and
fractionally recrystallized from hot ethyl acetate.” The less soluble
beta isomer crystallizes first and the alpha isomer accumulates in the
mother liquors. Pure methyl ox-l-arabinopyranoside melts at 131° C
and gives [o]}= + 17.3° (water, c=3).
NOTES
* Silver carbonate is prepared by mixing a 10-percent aqueous solution of silver
nitrate with a molecularly equivalent solution of sodium bicarbonate. The re-
sulting precipitate is collected on a filter and washed with water until free from
sodium salts, and then with methyl alcohol. The product is air-dried and pro-
tected from light.
* For other methods useful for separating glycoside mixtures, see page 513.
(2) METHYL o-d-ARABINOFURANOSIDE.
Method [12].-One hundred grams of powdered and sieved d-
arabinose is shaken at 20°C with 4 liters of anhydrous methyl alcohol
containing 29.2 g of hydrogen chloride (0.7 percent). Complete so-
lution occurs after about 30 minutes, and the solution is then allowed
to stand for 17 hours." The acid is removed by treating the mix-
ture with silver oxide,” and the excess silver is precipitated with hy-
drogen sulfide. The filtered solution is concentrated in vacuo to a
thick sirup,” which is dried overnight in a vacuum desiccator. The
sirup is then extracted six times with 400-ml portions of anhydrous
ether." The ether extract is evaporated in vacuo to a sirup which
weighs about 23 g.” The sirup is taken up with ethyl acetate and
allowed several days to crystallize.” The crystalline material, methyl
o-d-arabinofuranoside, when separated and dried, weighs about 11.5 g.
It is recrystallized by slowly cooling a warm ethyl acetate solution
of the material to 5° C. The crystals melt at 65° to 67° C and
give [o]}= + 123° (water, c=1).
Polarimetry, Saccharimetry, and the Sugars 515
NOTES
| Montgomery and Hudson [12] report that the solution, upon standing at
20° C, becomes nonreducing after 4.5 hours and has a specific rotation of
[o]}= +24°. On further standing the rotation increases to a maximum value of
[o]}}= + 45° in 17 hours and thereafter decreases to [o]}= — 17° in 42 hours.
* The acid must be completely removed, since the furanosides are very un-
stable in the presence of acids and water.
* Unless a flask is used which is separable from the distilling head, it is well to
transfer the solution while is it still dilute to another container in which the
extraction may be readily carried out after the sirupy stage has been reached.
* Each extraction may be readily carried out by shaking the ether and sirup in
a shaking machine for 45 minutes.
* This furanoside is very hygroscopic and should be kept out of contact with
moist air during this and succeeding operations. Montgomery and Hudson
used a cabinet (55 by 39 by 43 cm) constructed of copper and with a glass top
and removable end with strip-felt closure. The other end was provided with 2
openings 13 cm in diameter into which long rubber gloves were fitted with ad-
hesive tape.
* The first crystals were obtained by allowing the solution to stand at 5° C for
Several months.
(b) USE OF CALCIUM CHLORIDE COMPOUNDS TO SEPARATE GLYCOSIDES
(1) METHYL d-GULOPYRANOSIDEs.
Method' [4].-Forty grams of o-d-gulose CaCl2.H2O is refluxed
for 6 hours with 300 ml of absolute methyl alcohol containing 4.5 g
of anhydrous hydrogen chloride. The warm solution is slowly neu-
tralized with a slight excess of finely powdered calcium carbonate.
After the addition of about 1 g of decolorizing carbon, the solution is
filtered. The filtrate is concentrated in vacuo to a thick sirup,
which is diluted with 50 ml of absolute ethyl alcohol. In the course
of several hours, a crystalline product separates. The crystals are
collected on a filter and washed with a mixture of equal parts of
absolute ethyl alcohol and ethyl acetate. The mother liquor is
evaporated in vacuo to a sirup which is saturated with ethyl acetate,
and additional crystals are obtained.”
The dextrorotatory crystals are combined and recrystallized from
ethyl alcohol to givennethyl cy-d-guloside.CaCl2.2H2O and [o]}= +66.8°
(water, c=7). The levorotatory crystals are combined and recrys-
tallized to give pure methyl 3-d-guloside.CaCl2.2H2O“and [o]}=–45.7°
(water, c=2).
The free glycosides are obtained by shaking the calcium chloride
compound in water solution with silver oxalate, silver sulfate, or
silver carbonate. The resulting insoluble calcium and silver salts
are separated by filtration and the free glycoside is crystallized from
the aqueous solution. Methyl cº-d-gulopyranoside crystallizes as a
monohydrate which melts at 77° C and gives [o]}= + 109.4° (water,
c=2). Methyl 3-d-gulopyranoside melts at 176° C and gives
[o]}= —83.3° (water, c=3).
NOTES
1 Calcium chloride compounds have also proved useful for the preparation of
methyl ox-d-a-glucoheptopyranoside [5], of methyl 3-d-mannofuranoside [6], and
for the separation of the methyl 2,3,6-trimethylglucofuranosides [7]. If calcium
chloride is not present in the original sugar it must be added in the appropriate
uantity.
Cl 2 The preparation of o-d-gulose. CaCl2.H2O is described on page 465.
3 In a typical experiment the first crop of crystals weighed 15 g and gave
[a]}= +60.8°; the second crop, 3.72 g, [a]}= +37.5°; the third crop, 6.0 g,
[o]}= + 17.3°; the fourth crop, 3.5 g, [o]}=-36.0°.
516 Circular of the National Bureau of Standards
* These compounds crystallize from solutions containing 1 mole or more of
calcium chloride; compounds containing less calcium chloride are obtained under
different conditions.
(c) PREPARATION OF GLYCOSIDES FROM HALOGENO-ACETYL DERIVATIVES
The Koenigs-Knorr reaction [13].-By treating certain halogeno-
acetyl sugars in methyl alcoholic solution with silver carbonate, the
halogen is replaced by a methoxyl to give the acetylated glycosides,
of the same ring structure as that of the halogeno-acetyl sugar used.
The replacement of the halogen is usually accompanied by Walden
inversion, and as pointed out by Isbell [14] normal glycosides are
formed in good yield from halogeno-acetyl sugars having the halogen
and acetyl groups on the same side of the sugar ring, whereas ortho-
acetic esters are formed from halogeno-acetyl sugars having the
halogen and acetyl groups on opposite sides of the sugar ring. -
Glycosides having complex aglucone groups may be prepared from
the halogeno-acetates by use of various alcohols and phenols. If a
solid alcohol or phenol is to be used, the substance in solution in an
inert solvent such as benzene, or quinoline, is condensed, usually
in the presence of silver carbonate or silver oxide, with the halogeno-
acetyl sugar dissolved in a similar solvent [15,). The addition of a
dehydrating agent, such as calcium chloride or Drierite [16], frequently
improves the yields of the desired product. This method has also
been applied to the preparation of furanoside derivatives [17].
Pyridine, quinoline, and sodium hydroxide have been used in place
of silver carbonate. By treating the halogeno-acetyl derivatives in
alcoholic solution with mercury salts instead of silver salts, Zemplén
and Gerecs have worked out optimum conditions for the selective
preparation of either the alpha or beta ethyl cellobiosides [18]. In
general, by this method the formation of alpha isomers seems to be
favored by approximately equivalent concentrations of halogeno-
acetate, alcohol, and mercury salt [18, 19]. Another method consists
in condensing alcoholic solutions of the fully acetylated sugars in the
presence of sublimed ferric chloride [20]. By the use of 1 mole of
ferric chloride for each mole of the acetate, 20-percent yields of ethyl
heptaacetyl-a-cellobioside are obtained.
(1) METHYL TETRAACETYL-6-d-GLUCOPYRANOSIDE.
Method [13].-Ten grams of bromo-tetraacetylglucose is dissolved in
150 ml of absolute methyl alcohol at room temperature and shaken
with 10 g of dry powdered silver carbonate. The mixture is shaken
until a halogen test of the solution is negative (about 6 hours). The
mixture is filtered and the silver salts are washed with ether. The
filtrate is treated with water and a little barium carbonate, and after
a second filtration it is concentrated in vacuo to a heavy sirup which is
extracted with ether. The combined ether extract is washed with
sodium carbonate solution, then with water, and finally dried with
sodium sulfate. **
Methyl tetraacetyl-3-d-glucopyranoside crystallizes upon concen-
tration of the solution. It is recrystallized from methyl alcohol or
ligroin. The crystals melt at 105° C and give [o]}=–18.2°
(chloroform, c=4).
(d) PREPARATION OF PHENOLIC GLY COSIDES FROM ACETYL DERIVATIVES
A very good method for preparing glycosides of phenols is that of
Helferich and Smitz-Hillebrecht [21]. The phenol is melted with the
Polarimetry, Saccharimetry, and the Sugars 517
acetyl sugar in the presence of zinc chloride or p-toluene sulfonic a
The zinc chloride customarily yields alpha glycosides, and the p--oid
enesulfonic acid, beta glycosides. Glycosides of polyhydric alcohols
and phenols have been prepared with several sugar residues in the
molecule. The method is carried out by condensing the polyhydric
phenol with the acetylated sugar and then reacting the product with
a bromo-acetyl sugar in an aqueous acetone solution of sodium
hydroxide.
(1) PHENYL TETRACCETYL-o-d-GLUCOPYRANOSIDE.
Method [21]..—A mixture of 50 g of 3-pentaacetylglucose, 46 g of
phenol, and 12.5g of anhydrous zinc chloride is heated in a bath at 125°
to 130° C. for 45 minutes while mechanically stirred. The dark solution
is allowed to cool and is then dissolved in 300 ml of benzene and sev-
eral hundred milliliters of water. The benzene solution is washed
with water, then several times with 2 N sodium hydroxide solution,
and finally several times with water. The solution is dried with
calcium chloride and evaporated to a thick sirup, which is dissolved
in hot alcohol and allowed to crystallize. After several recrystalli-
zations from absolute alcohol, about 13 g of pure phenyl tetraacetyl-
o-d-glucopyranoside is obtained. The compound melts at 114° to
115° C and gives [o]}= + 168° (chloroform).
The phenyl cº-d-glucopyranoside is readily prepared from this
material by deacetylation, using the method of Zemplén (see p. 494).
(2) PHENYL TETRAACETYL-3-d-GLUCOPYRANOSIDE.
Method [21]..—A mixture of 292 g of phenol, 3.9 g of p-toluenesulfonic
acid, and 300 g of 3-pentaacetylglucose is heated for 90 minutes, while
mechanically stirred, in a boiling-water bath. The solution when cool
is taken up in 400 ml of benzene and worked up as described above for
the alpha isomer. The crystals obtained after recrystallization from
alcohol weigh about 140 g. Phenyl tetraacetyl-3-d-glucopyranoside
melts at 124° to 125°C and gives [o]}=–22.0° (chloroform).
(e) PREPARATION OF GLY COSIDES FROM SUGAR MERCAPTALS
This method is particularly useful for preparing furanose glycosides
[23], but it may also be used for obtaining the pyranose glycosides
[24], the thiofuranosides, and the thiopyranosides. The method con-
sists in treating the sugar mercaptal dissolved in the alcohol with
mercuric chloride, and when furanosides are desired, mercuric oxide.
The product formed depends upon the conditions employed. Thus
the galactofuranosides are formed at room temperature and in neutral
ethyl alcoholic solution in the presence of mercuric oxide. In a boil-
ing solution containing hydrogen chloride (which is formed during the
reaction) the ethyl cº-d-galactopyranoside is produced in 90-percent
yield. A water suspension of the galactose ethyl mercaptal, mercuric
oxide, and mercuric chloride gives at 0° C the crystalline ethyl
galactothiofuranoside.
(1) ETHYL d-GALACTOFURANOSIDEs.
Method [25].--To a solution of 28 g of galactose ethyl mercaptal
in 250 ml of absolute alcohol at 70°C, 35 g of yellow mercuric oxide
and 10 g of powdered Drierite" are added. The mixture is stirred
rapidly while a solution of 35 g of mercuric chloride in 150 ml of abso-
lute ethyl alcohol is added over a period of 30 to 40 minutes. The
reaction mixture is allowed to cool to 30° C over about an hour's
518 Circular of the National Bureau of Standards
time. It is then filtered, 10 ml of pyridine is added to the filtrate, and
the solution is allowed to stand at 0° C overnight. The pyridine–
mercuric-chloride compound is separated by filtration; the filtrate is
evaporated in vacuo to a sirup, which is dissolved in 100 ml of water,
neutralized with dilute alkali (phenolphthalein indicator), and the
solution again evaporated to a sirup. This sirup is dehydrated by
several distillations with absolute alcohol, and finally a thick sirup is
left. This is taken up with hot ethyl acetate, and the solution cooled
and decanted from the sirupy phase which forms during the cooling.
Seed of ethyl 3-d-galactofuranoside” is added and crystallization is
allowed to take place in a refrigerator. About 10 g of ethyl-3-d-
galactofuranoside is obtained. The material, after recrystallization
from 30 ml of hot ethyl acetate, melts at 85° to 86° C and gives
[a]}= –102° (water, c=1).
The mother liquor is concentrated in vacuo to a volume of 200 ml
and crystallization is allowed to take place. The crystalline mixture
of alpha and beta galactofuranosides may be mechanically separated
since ethyl 3-d-galactofuranoside crystallizes as white fragile needles,
while ethyl ord-galactofuranoside * separates as round translucent but-
tons which cling to the wall of the flask. The crude alpha isomer is
purified by recrystallization from 100 times its weight of hot ethyl
acetate from which it crystallizes in short needles. Ethyl ord-galacto-
furanoside melts at 140°C and gives [o]}= +92° (water, c=1).
NOTES
1 Drierite is a trade name for an anhydrous calcium sulfate.
* Nomenclature as given in reference [25].
(2) METHYL d-GLUCOPYRANOSIDEs.
Method [24].-Glucose dibenzyl mercaptal (8.2 g) is dissolved in
100 ml of boiling methyl alcohol and a solution of 16.3 g of mercuric
chloride in 30 ml of warm methyl alcohol is added. After the solution
has been heated for 15 minutes on the water bath, the precipitate of
CeBIs—CH2—S.–HgCl is removed by a filtration. Dry hydrogen sulfide
gas is passed into the solution and it is again filtered. The filtrate is
neutralized with silver carbonate, treated with a decolorizing carbon,
and filtered. The filtrate is evaporated in vacuo to a sirup, which is
taken up in a little cold water and filtered to remove the insoluble
portion. The aqueous solution is concentrated under reduced pres-
sure to a heavy sirup, which is brought to crystallization by the addi-
tion of absolute alcohol. The product is separated and recrystallized
from 18 parts of hot absolute alcohol. About 2.8 g of methyl cº-d-
glucopyranoside is obtained. It melts at 166° C and gives [o] }=
+158.9° (water, c=10).
The mother liquors from the preparation of the alpha isomer are
allowed to stand in a refrigerator. After several days the resulting
crystals of methyl 3-d-glucopyranoside are separated and recrystallized
from 8 parts of absolute alcohol. About 0.7 g of methyl 3-d-gluco-
pyranoside is obtained. The compound melts at 105° C and gives
[o] }= —34.2° (water, c= 10).
(f) PREPARATION OF GLYCOSIDES FROM SUGARS WITH DIMETHYL SULFATE
By careful methylation with one equivalent of dimethyl sulfate,
methyl glycosides may be obtained directly from the sugars [5, 26].
Polarimetry, Saccharimetry, and the Sugars 519
(1) METHYL 8-d-MANNOPYRANOSIDE ISOPROPYL ALCOHOLATE.
Method" [5].-A solution of 18 g of mannose dissolved in 100 ml
of water is kept in an ice bath and stirred while dimethyl sulfate and
30-percent sodium hydroxide are added dropwise over a period of 2
to 3 hours at such a rate as to maintain the reaction of the solution
alkaline to acyl blue (pH 12). Fifteen milliliters of dimethyl sulfate
is added over a period of 2 to 3 hours, and 20 to 22 ml of alkali in the
course of 8 hours. After the solution has stood overnight at room
temperature, it is neutralized with sulfuric acid and filtered. A small
quantity of barium carbonate is added to the filtered solution, which
is then concentrated in vacuo to a volume of approximately 30 ml.
After the addition of 60 ml of dioxane and a second evaporation, the
solution is concentrated to a thick sirup, which is dissolved in 60 ml
of pyridine. The solution is filtered, mixed with an equal volume of
acetic anhydride, and allowed to stand overnight at room tempera-
ture. It is then poured with stirring into a mixture of cracked ice
and water, and the acetylated glycoside is extracted with chloroform.
The chloroform solution is washed successively with solutions of
sodium bicarbonate and copper sulfate (until free from pyridine), and
finally with water. The chloroform solution is dried, filtered, and
evaporated to a sirup which is brought to crystallization by the addi-
tion of ethyl alcohol and further concentration. The material is
removed from the flask with ether (100 ml) and petroleum ether
added to saturation. After the mixture stands for a day at 0° C,
the crystals are collected on a filter and washed with a mixture of
ether and petroleum ether. The yield of the mixed alpha and beta
methyl tetraacetylmannosides is about 18 g. This material is stirred
with 100 ml of ether and filtered. The insoluble portion, about
6 g, is nearly pure methyl tetraacetyl-3-d-mannopyranoside. The
compound melts at 161°C and gives [o]}=–50.4° (chloroform, c=1).
The acetylated glycoside is deacetylated by the barium methylate
method described on page 493. After the barium is removed, the
resulting solution is treated with a decolorizing carbon, filtered, and
evaporated in vacuo to a heavy sirup, which is taken up in 10 ml of
isopropyl alcohol. After the mixture has stood for a short time,
methyl 3-d-mannoside, containing isopropyl alcohol of crystallization
(C.H.I.O.5. C3HsO) separates in large thin plates. The yield is nearly
quantitative. Methyl 3-d-mannopyranoside isopropyl alcoholate
melts at 74° to 75° C and gives [o]}=–53.3° (water, c=4).
NOTE
1 The methylation described here is like that used by Schlubach and Maurer
[26] for the preparation of 3-methyl glucoside. The dimethyl sulfate method is
particularly useful for the preparation of those glycosides in which the methoxyl
and the hydroxyl on the adjacent carbon are cis, because such glycosides are not
produced in satisfactory yield by the Koenigs-Knorr reaction. Methyl 3-d-
mannopyranoside may be prepared also by the hydrogen chloride method [27].
(g) PREPARATION OF GLYCOSIDES BY THE USE OF ALKYL IODIDES AND SILVER
OXIDE
(1) METHYL TETRAACETYL-3-d-FRUCTOPYRANOSIDE.
Method [28].-Sixty grams of powdered tetraacetylfructose, 375 g
of freshly prepared silver oxide, and 340 ml of methyl iodide are
boiled on the water bath for 6 hours in a 2-liter flask fitted with a
520 Circular of the National Bureau of Standards
reflux condenser which is supplied with ice water in order to prevent
loss of the solvent.” The methyl iodide is then distilled off and re-
covered.” The residue from the distillation is mixed with ether, and
the solution filtered and evaporated in the air. On seeding the result-
ing colorless sirup, crystalline methyl tetraacetyl-3-d-fructopyranoside
is obtained in almost the theoretical yield. The product, purified by
recrystallization from petroleum ether, melts at 75° to 76°C and gives
[o]}= –124.6° (chloroform, c=8).
NOTES
| A general review of the methylation method is given in reference [29].
* The reaction can also be carried out at room temperature if the mixture is
shaken and a longer reaction time is allowed.
* A large flask should be used for this evaporation in order to prevent loss by
bumping.
(2) METHYL cº-d-MANNOFURANOSIDE.
Method [30]..—Four-tenths gram of 2,3–5,6-mannose dicarbonate is
dissolved in methyl iodide containing a little acetone, and small
amounts of silver oxide are added at intervals during a half hour,
while the solution is heated below the boiling point. Prolonged con-
tact with large excesses of silver oxide is harmful. The solution is
filtered and the residue extracted with boiling acetone. The original
filtrate and the acetone extracts are evaporated and the residue is
again treated with the methylating agents as before. The filtrate
from the second treatment yields on evaporation 0.15 g of methyl
2,3-5,6-o-d-mannofuranoside dicarbonate. This product separates
in colorless crystals which are sparingly soluble in ethyl acetate and
melt at 172° to 173°C with decomposition. The carbonate groups are
removed by saponification with barium hydroxide. The relatively
pure compound thus obtained crystallizes readily. Methyl cy-d-
mannofuranoside melts at 118° to 119° C and gives [o]}= +113°
(water, c=1).
Other methods for preparing glycosides.—A number of other methods
of limited applicability have been used for the preparation of glycosides.
Thus methyl cº-d-glucoside has been obtained by enzymatic synthesis
from aqueous methyl alcoholic solutions of glucose and o-glucosidase
[31].
Certain glycosides can be prepared conveniently by the oxidation of
glycals with perbenzoic acid in the presence of an alcohol. Methyl
o-d-mannoside is prepared in good yield by this method from glucal [32].
(h) REFERENCES
E. Fischer, Ber. deut. chem. Ges. 26, 2400 (1893).
E. Fischer, Ber. deut. chem. Ges. 47, 1980 (1914). -
º Levene, A. L. Raymond, and R. T. Dillon, J. Biol. Chem. 95, 699
1932).
H. S. Isbell, BS J. Research 8, 5 (1932) RP396.
H. S. Isbell and H. L. Frush, J. Research NBS 24, 125 (1940) RP1274.
E. Pacsu and A. Scattergood, J. Am. Chem. Soc. 61, 534 (1939).
K. Hess and K. E. Heumann, Ber. deut. chem. Ges. 72, 149 (1939).
E. Pacsu, J. Am. Chem. Soc. 52, 2571 (1930).
[9] E. F. Armstrong and K. F. Armstrong, The Carbohydrates, p. 21 (Long-
mans, Green, and Co., London, 1934).
[10] C. B. Purves and C. S. Hudson, J. Am. Chem. Soc. 56, 702, 708, 1969, 1973
1934
[11] C.S. Hudson, J. Am. Chem. Soc. 47,267 (1925).
[12] E. Montgomery and C. S. Hudson, J. Am. Chem. Soc. 59, 992 (1937).
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
9
Polarimetry, Saccharimetry, and the Sugars 521
[13] W. Koenigs and E. Knorr, Ber. deut. chem. Ges. 34, 957 (1901).
[14] H. S. Isbell, Ann. Rev. Biochem. 9, 70 (1940); H. L. Frush and H. S. Isbell,
... . . J. Research NBS 27,413 (1941) RP1429.
[15] A. Robertson and R. B. Waters, J. Chem. Soc. 1930, 2729; 1931 (1881).
[16] D. D. Reynolds and W. L. Evans, J. Am. Chem. Soc. 60, 2559 (1938).
[17] H. Schlubach and K. Meisenheimer, Ber. deut. chem. Ges. 67, 429 (1934).
18] G. Zemplén and A. Gerecs, Ber. deut. chem. Ges. 63, 2720 (1930).
19] G. Zemplén and Z. S. Nagy, Ber. deut. chem. Ges. 63, 368 (1930).
20] G. Zemplén and Z. Csörös, Ber. deut. chem. Ges. 64, 993 (1931).
[21] B. Helferich and E. Smitz-Hillebrecht, Ber. deut. chem. Ges. 66, 378 (1933).
[22] *Hºº R. Hiltmann, and W. Reischel, Liebigs Ann. Chem. 534, 276
1938).
[23] J. W. Green and E. Pacsu, J. Am. Chem. Soc. 59, 1205 (1937); 60, 2056 (1938).
[24] E. Pacsu, Ber. deut. chem. Ges. 58, 509 (1925).
[25] J. W. Green and E. Pacsu, J. Am. Chem. Soc. 59, 2569 (1937).
26] H. Schlubach and K. Maurer, Ber. deut. chem. Ges. 57, 1686 (1924).
27] H. G. Bott, W. N. Haworth, and E. L. Hirst, J. Chem. Soc. 1930, 2653.
28] C. S. Hudson and D. H. Brauns, J. Am. Chem. Soc. 38, 1216 (1916).
[29] C. R. Young, A General Review of Purdie's Reaction, Memorial Volume of
Scientific Papers of St. Andrews University 500th Anniversary.
[30] W. N. Haworth and C. R. Porter, J. Chem. Soc. 1930, 649.
[31] E. Bourquelot, H. Hérissey, and M. Bridel, Compt. rend. 156, 491 (1913).
[32] M. Bergmann and H. Schotte, Ber. deut. chem. Ges. 54, 1564 (1921).
10. MER CAPTALS
(a) PREPARATION OF MERCAPTALS
These substances are thioacetal derivatives of the aldehydo forms
of the sugars and are used for the preparation of acetylated aldehydo
derivatives (see p. 490), for the preparation of pyranose and furanose
glycosides (see p. 517), and for the isolation of sugars from impure
mixtures. The mercaptals of a large number of sugars have been
prepared by shaking the sugar with the mercaptan in the presence of
concentrated hydrochloric acid at room temperature. The process is
not applicable to disaccharides, as partial hydrolysis occurs. The
detailed procedure for the preparation of galactose ethyl mercaptal
given in this section is typical of the method in general.
(1) GALACTOSE ETHYL MERCAPTAL. -
Method. [1,2].-Fifty grams of galactose is placed in a 500-ml glass-
stoppered wide-mouth bottle and is dissolved at room temperature in
75 ml of concentrated hydrochloric acid (sp. gr. 1.19). Fifty ml of
technical ethyl mercaptan is then added and the mixture is shaken,
the pressure being released at intervals. After 5 minutes ice and
water is added to the reaction mixture. The crystalline product
which forms is separated by filtration and recrystallized, first from
absolute alcohol and then from hot water. About 37 g of pure
material is obtained which melts at 140° to 142°C.
(b) REFERENCES
[1] P. A. Levene and G. M. Meyer, J. Biol. Chem. 74, 695 (1927).
[2] M. L. Wolfrom, J. Am. Chem. Soc. 52, 2466 (1930).
11. OXIDATION PRODUCTS
(a) PREPARATION OF ALDONIC ACIDS
General characteristics.-In aqueous solution the aldonic acids es-
tablish an equilibrium between the free acid (I), the gamma lactone
(II), the delta lactone (III), and frequently condensation products.
522 Circular of the National Bureau of Standards
O OH O O
S / S Ş
c e- e-
nºon icon noon
O
noon acon Hooh
nºon H¢- neon
nºon noon He–
CH3OH CH2OH CH3OH
(I) Aldonic acid. (II) Aldonic (III) Aldonic
- y-lactone. 6-lactone.
The relative proportions of the free acid and delta and gamma lac-
tones vary greatly according to the configuration of the sugar acid
and according to the temperature and concentration of the solution.
To prepare the free acids, it is generally necessary to avoid lactone
formation. Usually the crystalline acid can be obtained by concen-
trating a freshly prepared aqueous alcoholic solution of the acid at a
low temperature as rapidly as possible. The use of isoamyl or butyl
alcohol is advantageous because these alcohols retard the rate of
lactone formation, facilitate removal of the water, and after partial
evaporation, leave a solvent from which the acid crystallizes readily.
The lactones, when pure, also crystallize readily, but frequently this
condition cannot be realized experimentally because of the simultaneous
formation of two lactones. If one dissolves mannonic acid in water,
the delta lactone is formed more rapidly than the gamma lactone, but
the two are formed simultaneously. After several hours the con-
centration of the delta lactone reaches a maximum and at this point
it may be crystallized from the solution. As the solution stands, the
concentration of the more slowly formed gamma lactone increases at
the expense of the free acid and the delta lactone until equilibrium is
reached, when nearly all the sugar acid may be present as the gamma
lactone. The position of equilibrium depends on the experimental
conditions and on the configuration of the acid. The equilibrium
state for gluconic acid permits the crystallization of either the free
acid or the delta lactone from the equilibrium solution. At tem-
peratures below 25°C free gluconic acid is obtained, whereas at tem-
peratures above 25°C the delta lactone crystallizes. Heating glu-
conic acid in a high-boiling solvent, such as butyl alcohol, results in
the formation of gluconic Y-lactone, which crystallizes when the solu-
tion is cooled. The sugar acids combine with alcohols readily to form
esters which sometimes interfere with the crystallization of the acids
or lactones. Heating the esters in alcoholic solution, especially in the
presence of a mineral acid, causes the formation of lactones. The
ethyl ester of gluconic acid crystallizes well and decomposes on heating
to give gluconic Y-lactone. Lactone formation is accelerated by acid
catalysts; consequently, if one wishes to prepare the free acid, the
presence of mineral acid is avoided, but if one wishes to establish
the equilibrium state quickly, as in the preparation of mannonic
y-lactone, a mineral acid is added.
The aldonic acids may be prepared from the aldoses with the same
number of carbon atoms by oxidation, from the ketoses with more
Polarimetry, Saccharimetry, and the Sugars 523
carbon atoms by degradation, or from either the aldoses or the ketoses
with fewer carbon atoms by means of the cyanhydrin reaction.
Certain acids may be prepared by mold fermentation [1]. Many
oxidizing agents have been used for oxidizing aldoses to sugar acids,
among which may be mentioned bromine [2], iodine [3], mercuric
oxide [4], and chlorine in the presence of bromides or iodides [5].
One of the best methods for the manufacture of the aldonic acids
is the electrolytic process of Isbell and Frush [6, 7]. The electrolysis
is conducted in the presence of a bromide so that the real oxidant is
bromine set free by electrolysis. Presumably the bromine reacts
with the sugar, forming the aldonic acid and hydrogen bromide.
If the reaction is conducted in the presence of calcium bromide and
calcium carbonate, the sugar acid and hydrogen bromide combine
with the calcium carbonate, regenerating the calcium bromide and
forming the calcium salt of the sugar acid. Inasmuch as only a small
quantity of bromide is used as a catalyst in the electrolytic process,
it is ordinarily not necessary to remove it after the oxidation is
complete. The method used for the preparation of calcium gluconate,
described on page 524, can be used for the preparation of any alkaline
earth salt of the sugar acids.
Bromine reacts with the aldoses in either acid or alkaline solution,
whereas iodine reacts only in alkaline solution. In the bromine
Oxidation the active oxidant in the acid solution is free bromine [8],
but in the alkaline solution the active oxidant is hypobromite. In
acid solution the ring modifications of the sugar appear to be con-
verted directly to the lactone [9], while in alkaline solution the open-
chain and enolic modifications appear to be oxidized. As shown by
the following equation, 2 moles of hydrobromic acid are formed by
oxidation of 1 mole of the sugar:
H H H H H H H H H O
CH2OHC–C––C–C–C + Br2 = CH3OH c-c-e-c-cºhn,
OH OH OH º OH, OH OH
O O

The hydrobromic acid which is formed greatly reduces the rate of
reaction, but the retarding effect can be overcome by the addition of
a neutralizing agent. Usually, calcium or barium carbonate is suit-
able for this purpose, but if one wishes to oxidize aldoses in the presence
of ketoses without damaging the latter, the oxidation should be con-
ducted in the presence of barium benzoate [10]. The hydrobromic
acid or the bromide formed as a byproduct of the oxidation is ordi-
narily removed with silver or lead carbonate. If the oxidation is
conducted in the presence of calcium or barium carbonate, it is
advisable to remove the calcium or barium first with sulfuric acid,
and then to remove the hydrobromic acid with silver carbonate.
Aldonic acids containing fewer carbon atoms than the parent sugars
may be obtained by oxidizing the sugars with gaseous oxygen in
alkaline solution [11, 12]. This method is satisfactory for either
aldoses or ketoses and may be used for identification purposes. The
preparation of potassium d-arabonate from levulose given on page 528
illustrates the method. The same substance is easily obtained from
d-glucose.
524 Circular of the National Bureau of Standards
Aldonic acids containing more carbon atoms than the parent sugar
are usually prepared by the cyanhydrin synthesis. Cyanides react
with the reducing sugars, forming nitriles which on saponification
yield acid amides that on further hydrolysis give the aldonic acids [13].
The reaction may be brought about either by hydrogen cyanide in
the presence of ammonia or by a metallic cyanide. Perhaps the most
convenient reagent is a mixture of sodium cyanide and calcium
chloride [14]. A solution of the sugar is mixed with a solution con-
taining an equivalent quantity of the cyanide, and after time has been
allowed for the addition reaction to take place, the resulting nitriles
are hydrolyzed with alkali or with acid. If alkaline hydrolysis is
employed, the product is conveniently separated in the form of basic
calcium salts [15]. If acid hydrolysis is used, the product can be
obtained directly in the form of the lactone. As may be seen from the
following equation, the addition of hydrogen cyanide to the aldose
results in the formation of the nitriles of two epimeric acids. These
acids differ merely in the configuration of the second carbon, and the
separation of the two is frequently a difficult process.
H H OH H H
HOCH2 C–C–C–C–C–CN
7.
H H OH H / OH OH H OH OH
CH2OH−C–C–C–C–CHO + HCN d-a-Glucoheptonic nitrile
OH OH H OH N H H OH H OH
N
HOCH2 C-C–C–C–C–CN
OH OH. H. O.H. H.
d-6-Glucoheptonic nitrile
The following methods may be employed for the purification and
separation of aldonic acids: (1) Precipitation as basic calcium salts,
followed by conversion to normal salts and their fractional crystal-
lization [15]; (2) separation of the acid as the amide [16]; (3) hydrolysis
of the nitriles to the free acids and separation of the products, as the
crystalline acids or as lactones [17, 18]; (4) formation of double salts
[19, 20); (5) formation of benzal compounds [21]; (6) formation of
phenylhydrazides [16]; (7) separation by means of lead [22], strontium
[23], magnesium [24], cadmium [25], potassium [11], Strychnine [26],
or brucine salts [27].
If the raw material for the preparation of the sugar acids by one of
the methods already given is not available, the sugar acid can be
made from another sugar acid by the inversion of the asymmetric
center on the second carbon (epimerization). This can be accom-
plished by heating the acid or lactone with pyridine, quinoline, or
aqueous barium hydroxide. The preparation of talonic acid from
galactonic acid, given on page 528, is a typical example of this method.
(1) PREPARATION OF CALCIUM GLUCONATE BY ELECTROLYTIC
OxIDATION."
Method [6, 7, 28].-A solution consisting of 45 g (0.25 mole) of
anhydrous dextrose and 8 g of calcium bromide in sufficient water to
make 1 liter is placed with 12.5 g of calcium carbonate in a 2-liter
three-necked flask. The flask is equipped with a mechanical stirrer
Polarimetry, Saccharimetry, and the Sugars 525
jºr
and two graphite electrodes 22 mm in diameter and sufficiently long
to reach the bottom of the flask.” The electrodes are connected with
a source of direct current at 5 to 10 volts. A current of 0.5 ampere
is passed through the solution and the quantity of electricity is meas-
ured. The amount of oxidation is nearly proportional to the quantity
of electricity used, and the oxidation is virtually complete when the
theoretical amount (13.4 ampere hours) has passed through the
solution.* The current is interrupted when a quantitative test for
reducing sugars shows that substantially all the sugar has been used.
The electrolyzed solution is filtered and concentrated in vacuo to a
thin sirup from which calcium gluconate crystallizes readily. The
crystalline salt is separated, and if desired, the mother liquors may be
returned to the electrolytic cell and after the addition of more sugar
and calcium carbonate the process may be repeated. The yield of
calcium gluconate obtained in a single run is about 45 g. The crude
salt is recrystallized by dissolving it in hot water and permitting
crystallization to take place while the solution is stirred and cooled.
NOTES
| Licenses under United States Patent 1,976,731 covering the electrolytic
process for the manufacture of calcium gluconate and other sugar acids may be
applied for from the Secretary of Commerce.
* Impregnating the electrodes with paraffin prolongs their life.
* Each mole of sugar requires 2 faradays (53.6 ampere hours).
* Sometimes a calcareous deposit forms on the electrodes which may be removed
by reversing the current. .
(2) PREPARATION OF CALCIUM LACTOBIONATE-CALCIUM BROMIDE.—
The method for the preparation of calcium lactobionate-calcium
bromide is essentially the same as that used for the manufacture of
calcium gluconate, except that one equivalent of bromine is added in
place of the calcium bromide and 1 faraday of electricity is used for
each mole of lactose. If desired, the electrolytic cell can be operated
in a continuous manner, in which case lactose, calcium carbonate, and
bromine are added, while calcium lactobionate-calcium bromide is
crystallized from the electrolyzed solution. In small-scale operations,
it is generally more convenient to add the lactose, bromine, and cal-
cium carbonate in batches rather than continuously and to separate
the product from time to time. To avoid the handling of bromine,
the process can be conducted by adding calcium bromide in place of
bromine and by using 2 faradays of electricity per mole of lactose.
The following procedure has been found to give satisfactory results:
Method [20].-One kilogram of precipitated calcium carbonate
and 3.6 kg of lactose dissolved in 10 liters of water are placed in a
20-liter crock equipped with a mechanical stirrer and eight graphite
electrodes 30 cm long and 2.3 cm in diameter. While the solution is
stirred vigorously, 0.8 kg of bromine is cautiously added. Consider-
able foaming occurs which can be controlled by adding a few milli-
liters of an antifoam agent such as normal hexyl alcohol. After the
bromine has been added, and the evolution of carbon dioxide has
subsided, a direct current is passed through the solution, using
alternate electrodes as anodes and cathodes. The current density
should be from 1 to 2 amperes per square decimeter of anode surface.
This requires about 6 volts. After about 280 ampere-hours, when
323414°–42
so tº
jº)
526 Circular of the National Bureau of Standards
substantially all the sugar has been oxidized, the electric current is
stopped but stirring is continued until the evolution of carbon dioxide
ceases. After filtration the electrolyzed solution is concentrated under
reduced pressure to a sirup, from which nearly pure calcium lacto-
bionate-calcium bromide crystallizes. The crystals can be grown
in the evaporating pan while concentration is taking place. The
resulting crystalline product is separated from the mother liquor by
FIGURE 114–Apparatus for the electrolytic oxidation of sugars.
means of a centrifugal machine and washed with a high-purity calcium-
lactobionate-calcium-bromide sirup. The mother liquors are ordi-
narily returned to the electrolytic cell and worked up with the follow-
ing batch. Yields of over 90 percent are obtained.
Recrystallization.—Three parts of the salt are dissolved in 2 parts
of boiling water. A small quantity of a decolorizing carbon is added
and the hot solution is filtered. The filtrate is seeded with powdered

Polarimetry, Saccharimetry, and the Sugars 527
crystalline calcium lactobionate-calcium bromide and allowed to
cool while kept in constant agitation. The crystals are collected on a
filter and washed, first with a small quantity of water saturated with
calcium lactobionate-calcium bromide and finally with aqueous alcohol
containing approximately equal volumes of alcohol and water. The
The product, after drying at 50°C, corresponds to the formula:
Ca(C12H2O3)2.Cabrº.6H2O. It contains 7.54 percent of calcium and
15.04 percent of bromine and gives [o]}= +18.7° (water, c=7.3). A
Saturated solution of the hydrated salt at 20°C contains 31.5 percent
by weight and has a density of 1.18 g per milliliter.
|NOTES
| Those desiring to use this process for the manufacture of calcium lactobiomate-
Calcium bromide may apply for a license from the Secretary of Commerce under
United States Patent No. 1,976,731 and No. 2, 186,975. The compound has been
introduced into the pharmaceutical trade under the name Ca-Br-Galactogluco-
nate.
(3) PREPARATION OF CALCIUM ALTRONATE AND ALLONIC LACTONE
BY THE CYANHYDRIN SYNTHESIs.
Method [29, 30]..—The following solutions are prepared: 50 g of
d-ribose in 500 ml of water; 18 g of sodium cyanide in 100 ml of water;
27 g of CaCl2.2H2O in 100 ml of water.
The sugar, cyanide, and calcium chloride solutions are mixed and
allowed to stand overnight. Then there is added slowly, in portions,
with vigorous stirring, 74 g of calcium hydroxide in 500 ml of water.
The solution is heated to 80° C and allowed to stand overnight or
until saponification is complete. The solution is again heated to
about 80° C and filtered while hot. The precipitate of basic calcium
salts is washed with lime water until the filtrate shows only a faint
test for chlorides.
The precipitate of basic calcium altronate and basic calcium
allonate is suspended in water and dilute oxalic acid is added until the
Solution is neutral." The calcium oxalate is separated by filtration
and washed with hot water. The filtrate contains calcium altronate
and calcium allonate. The solution is boiled down in vacuo to a
thin sirup (about a 20-percent solution) and alcohol is added until a
slightly opalescent mixture results. On standing, calcium altronate
crystallizes from the solution. The mixture is then allowed to stand
for several days in order to separate all the calcium altronate possible
at this point. Sufficient oxalic acid is added to the mother liquors
to remove the calcium. The solution, after removal of the calcium
oxalate, is evaporated to a sirup, from which crystalline allonic lactone
separates. The lactone is purified by recrystallization from water.
A small quantity of calcium altronate and a little allonic lactone
can be reclaimed from the mother liquors by converting them to the
calcium salts, separating the calcium altronate and allonic lactone
as before. The average yield from 50 g of ribose is about 25 g of
calcium altronate and 25 g of allonic lactone.
NOTE
* In place of oxalic acid, sulfuric acid or carbon dioxide may be used.
528 Circular of the National Bureau of Standards
(4) PREPARATION OF d-TALONIC ACID BY PYRIDINE REARRANGE-
MENT OF GALACTONIC ACID.
Method [25, 31].—Talonic acid is prepared from d-galactonic acid by
epimerization with pyridine. Eighty grams of d-galactonic lactone
monohydrate, 36 g of pyridine, and 500 ml of water are placed in a
1-liter flask and heated at 90° to 100° C for 115 hours. The solution
is then evaporated to about 100 ml under reduced pressure. The
residue in the flask is mixed with 25 g of cadmium carbonate and
1 liter of water. The resulting suspension is then boiled while the
volume is kept constant until nearly all the carbonate is dissolved.
The solution is then concentrated under reduced pressure to remove
the pyridine. The resulting sirup is diluted to 1 liter with water and
after treatment with a decolorizing carbon and boiling to dissolve all
cadmium galactonate, the hot solution is filtered. Fifteen grams of
cadmium hydroxide is added to the filtrate and the solution is boiled
for some time, filtered hot, and evaporated to about 400 ml, after
which it is allowed to stand overnight. The crystalline cadmium
galactonate which separates is removed by filtration and the filtrate
concentrated to about 100 ml and allowed to stand overnight. Cad-
mium galactonate which separates is removed again by filtration,
The filtrate is then evaporated to dryness and taken up in 100 ml of
water. The cadmium is removed by treating with hydrogen sulfide
to precipitate the metal. An excess of hydrogen sulfide is avoided
because it makes the filtration difficult. The precipitated cadmium
sulfide is separated by filtration and the filtrate is concentrated almost
to dryness under reduced pressure at a temperature of not more than
50° C. The residue in the flask is mixed with 500 ml of absolute
alcohol and allowed to stand in the ice box overnight. About 20 g of
crystalline talonic acid separates.
Recrystallization.—The crude talonic acid is dissolved in the least
possible quantity of water at 40° C. The solution is cooled and
poured into 5 volumes of absolute alcohol. After standing for several
hours in the refrigerator, the resulting crystals are separated. Pure
d-talonic acid melts at 138°C and gives [o]}=-|- 19° (water, c=4).
(5) PREPARATION OF POTAssTUM d-ARABONATE FROM LEVULOSE
BY OxIDATION IN ALKALINE SOLUTION.
Method [11].-A solution of 18 g (0.1 mole) of levulose in 150 ml of
water is added to 150 ml of 2 N potassium hydroxide in a flask equipped
with a mechanical stirrer and a tube for the introduction of oxygen.
The air in the system is displaced by oxygen and oxidation is allowed
to take place at about 20° C. Stirring is continued for about 1 day.
Then the reaction mixture is concentrated to a thin sirup, which is
diluted with 750 ml of methyl alcohol to precipitate the potassium
salt of the sugar acid. The alcoholic solution containing the excess
potassium hydroxide is decanted. The oily precipitate is dissolved in
water, and the solution is clarified with a decolorizing carbon and
evaporated. Crystals of potassium d-arabonate form during the
evaporation and are separated by filtration. The yield is about 70
percent.
(b) PREPARATION OF DIBASIC ACIDS
(1) PREPARATION OF MUCIC ACID BY THE OxIDATION OF GALACTOSE
WITH NITRIC ACID.
Method [32].-Five grams of galactose is treated with 60 ml of nitric
acid of 1.15 specific gravity (about 25 percent) and heated on a steam
Polarimetry, Saccharimetry, and the Sugars 529
bath with occasional stirring until the volume has diminished to
one-third. The following day the product is stirred with 10 ml of
water, and after 24 hours the crystallized mucic acid is separated and
washed with 25 ml of water. The product is recrystallized from hot
water. The method can be used for the quantitative estimation of
galactose or galactose-containing substances.
(c) PERIODIC ACID OxIDATION OF GLYCOSIDEs
Periodic acid oxidation of the methyl glycosides according to the
method of Jackson and Hudson [33] provides a convenient means for
the determination of ring structure and the configuration of the
glycosidic carbon. For an unknown substance it is merely necessary
to follow the rotatory change during oxidation and determine the
unused periodic acid by titration. In the oxidation, the alpha and
beta methyl pentapyranosides form D'- or L'-methoxy-diglycolic
aldehydes, giving [o]}=approximately + 124°. The alpha and beta
methyl hexapyranosides and pentafuranosides of the d series form
D'- or L'-methoxy-D-hydroxymethyl-diglycolic aldehydes which
give [o]}=about +120° and – 150°, respectively. The specific ro-
tation after oxidation indicates the configuration of the glycosidic
carbon, while the amount of periodic acid used indicates the ring
structure. Oxidation of a pentapyranoside or hexapyranoside requires
2 moles of periodic acid, while oxidation of a furanoside requires 1 mole.
Method [33].-A known weight of the glycoside (approximately 2 g
of the pentoside or 2.4 g of the hexoside) is dissolved in 98 ml of a
standardized solution of periodic acid (about 0.3 M) in a 100-ml
volumetric flask at 20°C. The rotatory change is followed at 20°C
until the rotation becomes constant." The excess periodic acid is
then determined as follows [34]: A sample of the solution of suitable
size is treated with 5 to 10 ml of a saturated solution of sodium
bicarbonate, 15 ml of 0.1 N carbonated arsenious acid, and 1 ml of
20-percent potassium iodide. After standing for 15 minutes at room
temperature, the excess arsenious acid is titrated with 0.1 N iodine
solution.
NOTE
1 For the subsequent oxidation to the diglycolic acids, isolation of the stron-
tium or barium salts and hydrolysis, see Jackson and Hudson [33].
(d) REFERENCES
. E. May and H. T. Herrick, Circular No. 216, 1 (1932). U. S. Dept. Agric.
. Kiliani, Liebigs Ann. Chem. 205, 183 (1880).
. Willstätter and G. Schudel, Ber. deut. chem. Ges. 51, 780 (1918).
. Heffter, Ber. deut. chem. Ges. 22, 1049 (1889).
. Stoll and W. Kussmaul, U. S. Patent 1,703,755 (1925).
. S. Isbell and H. L. Frush, BS J. Research 6, 1145 (1931) RP328.
. S. Isbell, U. S. Patent 1,976,731 (1934).
S. Isbell and W. W. Pigman, BS J. Research 10, 337 (1933) RP534.
. S. Isbell, BS J. Research 8, 615 (1932) RP 441.
ſ
:*
[10] C. S. Hudson and H. S. Isbell, BS J. Research 3, 57 (1929) RP82.
[11] O. Spengler and A. Pfannenstiel, Z. Wirtschaftsgruppe Zuckerind. 85, 546
(1935).
[12] N. K. Richtmyer, R. M. Hann, and C. S. Hudson, J. Am. Chem. Soc. 61,
340 (1939).
[
13] H. Kiliani, Ber. deut. chem. Ges. 18, 3066 (1885).
[14] ci, Hudson, O. Hartley, and C. B. Purves, J. Am. Chem. Soc. 56, 1248
1934).
[15] H. S. Isbell and H. L. Frush, BS J. Research 11, 649 (1933) RP613.
530 Circular of the National Bureau of Standards
[16] *M. Hann, A. T. Merrill, and C. S. Hudson, J. Am. Chem. Soc. 57, 2100
1935).
[17] E. Fischer and R. Stahel, Ber. deut. chem. Ges. 24, 528 (1891).
[18] F. B. LaForge, U. S. Patent 1,285,248 (Nov. 19, 1918).
[19] G. Bertrand, Bull. soc. chim. 5, 554 (1891).
[20] H. S. Isbell, J. Research NBS 17, 331 (1936) RP914.
21] w A. Van Ekenstein and C. A. Lobry de Bruyn, Rec. trav. chim. 18, 305
1899).
[22] H. S. Isbell, J. Research NBS 14, 305 (1935) RP770; 19, 639 (1937) RP1052.
[23] H. Kiliani, Ber. deut. chem. Ges. 59, 2462 (1926).
24] H. S. Isbell and H. L. Frush, J. Research NBS 14, 359 (1935) RP773.
25] O. F. Hedenburg and L. H. Cretcher, J. Am. Chem. Soc. 49, 478 (1927)
26] E. Fischer and J. Hertz, Ber. deut. chem. Ges. 25, 1256 (1892).
27] E. Fischer, Liebigs Ann. Chem. 270, 84 (1892).
28] H. S. Isbell, H. L. Frush, and F. J. Bates, BS J. Research 8, 571 (1932)
RP436; also Ind. Eng. Chem. 24, 375 (1932).
[29] F. P. Phelps and F. J. Bates, J. Am. Chem. Soc. 56, 1250, (1934).
30] P. A. Levene and W. A. Jacobs, Ber. deut. chem. Ges. 43, 3141 (1910).
31] I. H. Cretcher and A. G. Renfrew, J. Am. Chem. Soc. 54, 1590 (1932).
[32] Methods of Analysis, Assn. Official Agr. Chem. (Washington, D. C., 4th ed.
1935), p. 345.
[33] E. L. Jackson and C. S. Hudson, J. Am. Chem. Soc. 59, 994 (1937).
[34] P. Fleury and J. Lange, J. pharm. chim. (8) 17, 107 (1933).
12. REDUCTION PRODUCTS
(a) ALCOHOLS
General characteristics.-The sugar alcohols may be prepared by
reduction of the sugars and sugar acids with sodium amalgam, by
catalytic reduction of the sugars with hydrogen, or by electrolytic
reduction of the sugars. Electrolytic reduction of sugars has been
developed commercially under the patents of Creighton [1, 2]. The
reaction is carried out by cathodic reduction of the sugar, using lead
electrodes and sodium sulfate as electrolyte. Sorbitol and mannitol
are obtained from dextrose by this process. The catalytic reduction
of the sugars to polyhydric alcohols with hydrogen was reported by
Ipatieff in 1912 [3]. Glucose was reduced to sorbitol, fructose to
mannitol (and presumably sorbitol), while lactose was split and
reduced to dulcitol (and presumably sorbitol). Senderens [4] studied
the high-pressure hydrogenation of lactose further, and obtained a
crystalline lactositol hydrate from the sirupy mother liquor after
removal of the dulcitol. Böeseken and Leefers [5] used a nickel and
cobalt catalyst and hydrogenated glucose in 95-percent alcohol.
Nickel catalysts, such as Raney nickel [6] are generally used in sugar
hydrogenation [7, 8, 9].
(1) REDUCTION OF d-o-GLUCOHEPTOSE WITH SODIUM AMALGAM. To
GIVE d-o-GLU coh EPTITOL.
Method [10].-Ten grams of d-a-glucoheptose is dissolved in 100 ml
of water at room temperature, and after addition of 4 ml of 20-percent
sulfuric acid, 300 g of pure 2.5-percent sodium amalgam is intro-
duced. The mixture must be continuously shaken and the reaction
of the solution must be held slightly acid or neutral by the frequent
addition of dilute sulfuric acid. When the sodium amalgam is spent,
the mercury is separated and if the solution gives a positive test for
reducing sugar, 200 g of sodium amalgam is added and the process is
repeated while the reaction is held neutral to slightly alkaline. When
the reduction is complete, as shown by a negative test for reducing
sugars with Fehling solution, the aqueous liquid is decanted from the
Polarimetry, Saccharimetry, and the Sugars 531
mercury, neutralized with sulfuric acid, treated with a small quantity
of a decolorizing carbon, and filtered. The filtrate is diluted five-fold
with warm alcohol, filtered after cooling, and evaporated in vacuo to
a sirup. After cooling and standing, the sirup yields crystalline
d-o-glucoheptitol almost quantitatively. The crystalline mixture
is triturated with alcohol, filtered, and recrystallized from ethyl or
methyl alcohol. Pure d-a-glucoheptitol melts at 127° to 128°C and is
optically inactive.
(b) GLY CALS
General characteristics.-The glycals are unsaturated derivatives
containing two hydroxyls less than the parent sugars. Usually they
are prepared by the reactions represented by the following equations:
H Br H H
N / N. N.
º g- º
|
Hºos, HC nº
|
soºn O ACOHC O noºn O
- .
Hºos. Reduction H COAC Deacetylation noon
º (Zn dust) HC Ba Methylate ne- ---
Hoose H COAC con
- |
H H H
1-Bromo-2,3,4,6- Triacetylglucal. Glucal.
tetraacetyl-o-d-
glucose.

The glycals are of importance because they can be used for the
preparation of new sugars and sugar derivatives. Oxidation of glycals
with perbenzoic acid followed by treatment with water gives a mixture
of the two epimeric sugars [11]; hence, by conversion of a sugar into
its glycal and subsequent oxidation, the epimeric sugar may be pre-
pared. Strangely, substitution of the hydroxyls greatly alters the
proportions of the epimeric sugars produced. Thus the oxidation of
triacetylglucal gives almost exclusively glucose derivatives, whereas
the oxidation of glucal gives glucose and mannose, with mannose in
predominating quantity [11, 12]. By treating glycals with perben-
zoic acid in the absence of water, followed by the addition of methyl
alcohol, methyl glycosides are obtained [11]. The products obtained
by the perbenzoic acid oxidation usually contain small quantities of
monobenzoyl derivatives [13].
Treatment of the glycals with cold aqueous sulfuric acid gives sul-
furic esters which on hydrolysis yield desoxy sugars. Chlorine adds
to the double bond to give a mixture of epimeric 1,2-dichloro deriva-
tives, while hydrobromic acid appears to give 2-bromo derivatives
[14]. Oxidation of the glycals with ozone splits the molecule at the
double bond. Reduction with hydrogen in the presence of a catalyst
yields hydroglycals [14]. The behavior of the glycals towards hy-
drogen chloride provides a convenient qualitative test: A pine splinter
moistened with a glycal solution and exposed to hydrogen chloride
gas turns green.
532 Circular of the National Bureau of Standards
The tendency of the glycals to undergo intramolecular change is
particularly noteworthy and should be kept in mind when working
with these products. Boiling triacetylglucal with water results in
the migration of the double bond to the 2,3 position and the hydrolysis
of one acetyl group [15]. The product, diacetylpseudoglucal, on
treatment with barium hydroxide, undergoes further rearrangement
to give isoglucal and protoglucal [16].
H H OH
`c Neº CH3 CHO
&H CH 6–0 ch
Aoki O &H O –C–H &
Hêose Hoos . chon CH,
Hé Hé () Chou chon
chos - chos —on He
h h
Triacetylglucal Diacetyl- Isoglucal Protoglucal
pseudoglucal


(1) TRIACETYLGALACTAL AND GALACTAL.
Method [13].--To a 12-liter flask surrounded by an ice-salt bath
there is added 1,000 ml of water, 500 ml of acetic acid, and 100 g of
zinc dust which is kept in suspension by the aid of a mechanical
stirrer. During a period of 3 hours, ten 75-g portions of finely pow-
dered bromotetraacetylgalactose, each dissolved in 300 ml of warm
glacial acetic acid, are added. Water is added in quantities to keep
the composition at approximately 50-percent acid, and 600 g of zinc
dust is added in portions at intervals during this period. The tem-
perature is allowed to rise slowly to room temperature over a period
of 18 hours. Then the mixture is filtered," and the filtrate is extracted
four times with a total of about 11 liters of benzene. The washed
extracts are evaporated at a pressure of 14 mm to a thick sirup. The
weight of the sirup, obtained by the combination of two such prepara-
tions from a total of 1,370 g of the bromo-tetraacetylgalactose, is
about 685 g. This sirup is then purified by distillation at 140° to
155°C at a pressure of approximately 0.05 mm. The distillate (500 g)
is deacetylated by dissolving it in 4 liters of dry methyl alcohol con-
taining 0.1 mole of barium methylate.” After standing for 18 hours
in the refrigerator, the solution is saturated with carbon dioxide and
the barium carbonate is separated and discarded. The alcoholic
solution is evaporated in vacuo to a thick sirup, which is dissolved in
200 ml of absolute alcohol and evaporated again. The resulting sirup
is extracted with absolute ethyl alcohol. The insoluble residue is
discarded and the extracts are concentrated to a sirup containing about
60 percent of solids. The galactal crystallizes readily from this
solution. It is separated by filtration and recrystallized from hot
ethyl acetate. About 200 g of the recrystallized product is obtained
from 500 g of the acetate. The pure substance melts at 100° C.
Polarimetry, Saccharimetry, and the Sugars 533
NOTES
| Care must be taken to avoid oxidation of the zinc dust, which takes place when
air is sucked through the residue on the filter.
* Sufficient barium methylate must be used to neutralize any acid present in
the distillate and to leave an excess. This can be ascertained by diluting a small
Sample with water and adding phenolphthalein. An excess is indicated by a
red color.
(c) REFERENCES
. J. Creighton, Trans. Electrochem. Soc. 75, 289 (1939).
. H. Killeffer, Ind. Eng. Chem. (News ed.) 15, 489 (1937).
. L. Ipatieff, Ber. deut. chem. Ges. 45, 3224 (1912).
. B. Senderens, Compt. rend. 170, 47 (1920).
. Böeseken and J. L. Leefers, Rec. trav. chim. 54, 861 (1935).
. Raney, U. S. Patent 1,563,587.
. L. Wolfrom, W. J. Burke, K. R. Brown, and R. S. Rose, Jr., J. Am. Chem.
Soc. 60, 571 (1938).
. A. Levene and M. Kuna, Science 85, 550 (1937).
. Müller and T. Reichstein, Helv. Chim. Acta 21, 251 (1938).
. Fisher, Liebigs Ann. Chem. 270, 80 (1892).
. Bergmann and H. Schotte, Ber. deut. chem. Ges. 54, 440, 1564 (1921).
. A. Levene and R. S. Tipson, J. Biol. Chem. 93, 631 (1931).
. W. Pigman and H. S. Isbell, J. Research NBS 19, 204 (1937) RP1021.
º M. Bergmann, and H. Schotte, Ber. deut. chem. Ges. 53, 509
1920).
. Bergmann and W. Freudenberg, Ber. deut. chem. Ges. 64, 158 (1931).
. Bergmann, L. Zervas, and J. Engler, Liebig’s Ann. Chem. 508, 25 (1933).
XXXII. CRYSTALLOGRAPHY OF THE SUGARS
1. INTRODUCTION
All the sugars, being optically active, crystallize in one or another
of the 11 enantiomorphous crystal classes. An enantiomorphous crys-
tal is one which by reflection in a plane mirror yields an image like the
object, but laterally inverted, and which cannot be made by rotation
to resemble the first precisely, but behaves as a left hand does to a
right hand. Both varieties of the crystals are known in many cases,
familiar examples of which are right and left quartz and right and left
tartaric acid. Also both right and left forms of many of the sugars
have been prepared. By far the greater number of these fall into two
crystal groups: Class 4, which has only one symmetry element, namely
an axis of twofold or digonal symmetry; and class 6, which has three
digonal symmetry axes intersecting each other at 90°. Class 4 is the
only enantiomorphous class in the monoclinic system, and class 6 is
the only one in the rhombic or orthorhombic system. These two
classes only will be reviewed.
2. CHARACTERISTICS OF SYMMETRY CLASS 4 (MONOCLINIC
SPHENOIDAL)
The monoclinic or monosymmetric system is characterized by three
axes of unequal length, two of which, a and c, are inclined to each
other, but the third, b, is perpendicular to those two. This may be
written
a :b:c = ?:1:2 o–y =90, 8–?
Class 4 of this system is characterized by the fact that there are no
planes of symmetry and that only one of the three axes is an axis of
534
Circular of the National Bureau of Standards
symmetry, namely the b axis. Half of a complete revolution about
this axis restores the original appearance of the crystal.
(See fig. 115,
where the heavy dots represent crystal faces and the ellipse represents
FIGURE 115.-Symmetry elements of
* * * * ... * *
º • *
/ “ . . . ... . . . . . " ' "
class 4.
the digonal axis of symmetry.)
It is known as the sphenoidal
class, or digonal polar type, since
the two ends of the b axis are of
different crystallographic forms.
Table 63 shows the possible
: crystal forms of this class. Col-
i... umn 1 gives the form symbol;
column 2, the Millerian index
representing the form; column 3,
the number of faces which com-
prise the form; and column 4,
the name of the geometrical figure
which the form comprises. In
class 4 belong: Sucrose, a dextrose
hydrate, d-rhamnose monohy-
drate, o-lactose, and stachyose.
TABLE 63.--Crystal forms of class 4
POSsible forms
Form symbol Mººn Yºr Name of geometrical figure which the form comprises
“... -- - - - - - - - - {001} 2 | Basal pinacoid or third-order pinacoid.
ſt - {100; 2 Ortho-pinacoid or first-order pinacoid.
" ------------------- {010} 1 | Right clino-pedion or right Second pedion.
''' ------------------ {010; 1 | Left clino-pedion or left Second pedion.
P- - - - - - - - - - - - - - - - - - - - º 2 | Right monoclinic prism or sphenoid of third order.
110}
p'-------------------- { hk0) 2 | Left monoclinic prism or sphenoid of third order.
{110;
! -- - - - - - - - - - - - - - - - - - - - {h()l} 2 Negative hemi-Ortho-prism or negative pinacoid of Second
{101; Order.
"--------------------- {h()l} 2 | Positive hemi-Ortho-prism or positive pinacoid of Second
{101; Order.
7- - - - - - - - - - - - - - - - - - - - - - {Okl} 2 Right clino-prism or clino-dome, or right sphenoid of first
{011; Order.
º'------------------ { Okl } 2 | Left clino-prism or clino-dome, or left sphenoid of first order.
{011}
0 - - - - - - - - - - - - - - - - - - - - {hkl} 2 | Right negative monoclinic sphenoid of the fourth order.
{111}
"------------------ (hkl) 2 | Left negative monoclinic sphenoid of the fourth order.
{111}
0"------------------- { hkl) 2 Right positive monoclinic sphenoid of the fourth order.
{111}
0". . . . . . . . . . . . . . . . ---- {hkl} 2 Left positive monoclinic sphenoid of the fourth order.
Polarimetry, Saccharimetry, and the Sugars
535
(a) SUCROSE
Crystal system: Monoclinic.
Class 4: Monoclinic sphenoidal; monoclinic hemimorphic.
Symmetry type: Digonal polar, characterized by one digonal axis only.
Habit: Prismatic.
Ratio of ares: arb:c- 1.2595; 1:0.8782.
8–103°30' (Wolff) [3].
TABLE 64.—Crystal forms of sucrose

!
POSSible forms
Usual forms
observed
Crystal forms of class 4,
See p. 534.
TABLE 65.-Angular values between faces of sucrose crystals
Face form letter
Millerian
face Symbol
(100)–(001)
(100)-(101)
(100)–(101)
(100)-(110)
(001)–(101)
(001)–(101)
(001)–(011)
(110)–(110)
(110)-(110)
(011)–(011)
(111)–(111)
(111)–(101)
(110)-(001)
(111)–(001)
(210)–(100)
(210)-(110)
(320)–(100)
(320)-(110)
(530)-(100)
(530)-(110)
(410)–(100)
(410)–(110)
Calcu- || Hankel | Miller | Wolff º Rinne Phelps Yºr
lated [1] 1840 |2|1842|[3] 1843 | "...#" |[5] 1885 (6) 1931 |tiºn
76°30' | 76°30' | 75°30' | 76°30' | 76°43' || 76°15' | 76°25' | 7705/
46°15' | ----------|--|--|--|--|-------- 45°37' | _ _ _ _ _ _ _ 44°41’ 45°11'
64°30' | 63°45' 63°20' |_ _ _ _ _ _ _ _ 64°27' | 63°12' | 63°32' | 63°14'
50°48' | 50°00' |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 50°46’ 50°40' | 50°44' | _ _ _ _ _ _ _ _
30°15' | ----------|--|--|--|--|-- - - - - - - 31°20' | . . . . . . . . 31°42' | 31°50
39°00' 39°45' 41° 10' 39°00' | 39°17' | . . . . . . 40°00' | 39°45'
40°30' | ----------|--|--|--|--|--|--|--|--|----------|---...--- 40°19' 41°5'
73°28' | 80°00' | 79°20' | 78°28' | 78°30' | 78°48' | 78°43' | 78°41’
78°28' | ----------|--|--|--|--|--------|----------|---. ---. 78°53' |_ _ _ _ _ _ _ _
99°00' | -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - , 98°00' | _ _ _ _ _ _ _ _
115°12' |----------|--------|--|--|--|--|---------. . . . . . . . . 114°30' | _ _ _ _ _ _ _ _
32°24' ----------|--|--|--|--|--|--|--|--|--------- 32°52' |_ _ _ _ _ _ _ _
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ | 81°27'
- - - - - - - - I - - - - - - - - - - I - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- . i - - - - - - - - - - - 43°53'
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - , . i - - - - - - - - - - - - - - - - - - - - - 31°11'
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - I - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 199267
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 40° 13'
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 10°22'
- - - - - - - - - - - - - - - - - - - I - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - K -- a- - - - - - - - - - - - - - - - - - - 36°10'
-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ------|--...--...--|--|--|--|--|--| 14°1'
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 16°30'
- - - - - - - - - - 33°30'
| Calculated from the three italicized angles measured by Wolff.
Twinning: Frequent on the c axis.
Aacial plane: b{010}
Cleavage: Along a 100%.
Solubility: Greater rate of solution on one end than on the other.
Double refraction: Negative.
o:- 1.537, 3–1.565, y = 1.571.
Refractive indices.—The optical ellipsoid is a surface representing the
refractive index whose major, intermediate, and minor axes are deter-
mined by the maximum, intermediate, and minimum refractive indices
of the crystal.
The position of the optical ellipsoid with respect to
the reference axes is determined in part by the crystal symmetry.
For sucrose the axis of the optical ellipsoid which coincides with the
symmetry or b reference axis of the crystal happens to be the inter-
mediate axis; hence, the maximum and minimum axes, and conse-
536 Circular of the National Bureau of Standards
quently the two optic axes of the crystal, lie in the plane of the stereo-
graphic projection.
Becke [8] found that the median line which coincides with one of the
axes of the optical ellipsoid made an angle of 66°37' with the crystallo-
graphic c axis in the obtuse angle 3 (sodium light), as shown in the
stereographic projection (fig. 116). This value varies by about 6°
from one end of the spectrum to the other, i. e., the position of the
optical ellipsoid varies somewhat with the wave length of the light
used to measure it.
Becke [8] measured the angle between the optic axes for sodium
light and found it to be 48°0' (fig. 116). By calculation from the
measured refractive indices along the three principal directions of the
ellipsoid, he obtained the value 48°22'.
Merwin [9] has redetermined the three principal refractive indices
over a more extended range of wave lengths, as shown in table 66.
wn!
ºl
Sl
so I
coo!
'70ſ
Sº, A. 79
§
SF
Nº:
A Jol
**. ^
iž - -
\) º _4. až
Cz / 60 A to Xº * P 7/o Ortue @x is
o-rº zººs T A 7 o F Sºp 770
* 5 _ - *
a 24” N
& º *y *s,
e
ºn 707
$º.
e
Nº.
2"/o?
C ooi
|
g
N
CŞ|
\ºl
FIGURE 116.-Stereographic met for sucrose.
TABLE 66.-Refractive indices of crystalline sucrose [9]
X CY 8 ºy
Mu
405 Hg 1. 5524 1. 5803 1. 5858
436 Hg 1. 5484 1. 5762 1. 5816
502 He 1. 5425 1. 5702 1.5756
546 Hg 1. 5397 1. 5673 1. 5727
588 He 1. 5377 1. 5652 1. 5706
706 He 1. 5336 1. 5610 1. 5664


Polarimetry, Saccharimetry, and the Sugars 537
It will be noted from the stereographic projection (fig. 116) that
one of the optic axes is almost exactly perpendicular to the a faces
and the other is approximately perpendicualr to the r faces. Along
these two axial directions, sucrose in the crystalline state rotates the
plane of polarization. The most recent study of this interesting
phenomenon has been made by Longchambon [10] who gives — 15.6°
per centimeter as the rotation along the axis nearly perpendicular to
the a (100) faces, and +51° per centimeter along the other optic
axis, the rotation being of opposite sign along the two directions.
Other investigators have given somewhat larger values. The cohe-
sive forces tending to bind the units of the crystal together are least
along the direction perpendicular to the a faces, as evidenced by the
fact that the crystal cleaves easily into sections parallel to the a faces.
º perhaps accounts for the usual prominent development of these
8,CeS.
Stammer [11], Schaaf [12], Bock [13], and Wulf [14] have studied
FIGURE 117.-Swcrose crystal.
the effects of various impurities upon the form or relative develop-
ment of faces of sucrose crystals.
Their results may be summarized as follows: For pure sugar the
faces shown on quickly grown crystals are p, a, c, and r’ of somewhat
near equal development (fig. 117 and fig. 1.18a). On more slowly
grown crystals, the faces r, q, and o' are also usually developed, the
latter two on the left end, as shown in figure 117. On crystals that
have been rounded by filing and by solution, there frequently de-
velop the following faces in addition to those above: On the left
end, b, o, and 2p, and on the right end, o', o, and p. The presence
of molasses (containing raffinose) causes the faces r" to predominate
over c, frequently to the complete exclusion of the latter. Likewise,
considerable raffinose causes a long, slender prismatic development
along the b axis, as shown on the extreme right of figure 118b. The
presence of dextrose causes a thin plate-like development, the a faces
greatly predominating over all others.

538
Circular of the National Bureau of Standards
%
g
--Q.
e=Fº
Sº,
,
(L
Q.
d.
\
* -º 7S. #.
% (1 .
PP1 - a --
ALZ. - - -
2 g=-
% (Z A
p † |7
! a. *
7
FIGURE 118.-Drawings to illustrate growth and twinning habits of sucrose crystals
The letters used on the drawings identify the different crystal faces.
(a). Crystals grown from a pure sucrose solution.

Polarimetry, Saccharimetry, and the Sugars 539
- - “r G
8 º
18 - :
Gi *: €- : 8 :
18: I 8 || | G- 18
G- º GE & º 0. G *; .*
18 * 8 8 t
G- G- Jº : !....----------
8 * : *
G-
º :
G-
... . 8: …
18
& 8
8 *
*;





540 Circular of the National Bureau of Standards
(b) o-DEXTROSE HYDRATE
Class: 4, Monoclinic sphenoidal.
Ratio of aires: a,b;c=1.735:1:1.908.
3=97°59’ (Becke) [15]
Solubility: One end disolves much more quickly than the other.
Plane of optic aces: b {010}
Median line: Approximately perpendicular to {101}.
Aacial angle: Large.
Refractive indices: no, o – 1.517, 6–1.530, y = 1.555.
FIGURE 120.—Stereographic met for deactrose hydrate.
TABLE 67.-Crystal forms of dea:trose monohydrate
POSS1ble forms |USual forms
{001}
{110}
Class 4 (See p. 534) - - - - - - - - - - - {101;
{101}
{110}

Polarimetry, Saccharimetry, and the Sugars
541
TABLE 68.-Angular values between faces of deactrose monohydrate crystals

Face form | Millerian face | Measured
letter symbol angle
7m-m’ (1i0)-(110) 60°24'
l—c (101)–(001) 44°31'
d’—c (101)–(001) 5297/
TIZ-C (110)–(001) 85°59’
7m’—d’ (iiO)-(101) 69927/
7m-l (110)–(101) 66°27'
3. CHARACTERISTICS OF SYMMETRY CLASS 6 (RHOMBIC
BISPHENOIDAL)
The rhombic or orthorhombic system is characterized by three
rectangular axes, a, b, and c, all of
unequal length.
a :b:c= ?: 1:2 o'-6–) = 90°
Class 6 of this system is character-
ized by the fact that there are no
planes of symmetry but that all
three axes are axes of digonal sym-
metry. One-half of a complete.
revolution about any one of these
three axes will restore the crystal
to its original appearance. (See
fig. 121.)
It is known as the bisphenoidal
class, or digonal holoaxial type. The
possible forms of this class are shown
in table 69.
* * *..
* *
FIGURE 121.—Symmetry elements
of class 6.
TABLE 69.--Crystal forms of class 6
Possible forms
Form symbol Mººn Nº. Name of geometrical figure which the form comprises
C---------------------- {001} 2 | Basal pinacoid or third-order pinacoid.
(!---------------------- {100} 2 Macropinacoid or first-order pinacoid.
"-------------- - - - - - - - - {010} 2 | Brachy pinacoid or second-order pinacoid.
12---------------------- (hk0} 4 Rhombic prism of the third order.
p Or m {110} 4 DO. e
- - - - - - - - - - - - - - - - {h()l} 4 Macro-domal prism of the second order.
T---------------------- {101} 4 DO.
{0}{l} 4 || Brachy domal prism.
ſ!---------------------- {011} 4 | Rhombic prism of the first order.
O {hkl} 4 Right rhombic sphenoid.
- * - * ſº * * * * - - - - - - - - - - sº - 2- {111} 4 DO.
o'--------------------- (hkl) 4 | Left rhombic sphenoid.
{111} 4 DO.
323414°—42 36
542 Circular of the National Bureau of Standards
FIGURE 122.-Levulose crystal showing different development of faces.

Polarimetry, Saccharimetry, and the Sugars 543
In this class belong levulose, o-anhydrous dextrose, sorbose, man-
nose, trehalose, and raffinose.
(a) LEVULOSE
Crystal system: Orthorhombic.
Class 6: Rhombic bisphenoidal.
Symmetry type: Digonal holoaxial, characterized by three rectangu-
lar digonal axes of symmetry.
Habit: Prismatic.
Ratio of aires: arb:c=0.8007: 1:0.9067 (Schuster) [16].
FIGURE 123.−Stereographic met for levulose crystal.
TABLE 70.-Angular values between faces of levulose crystals
Face form Millerian Measured
letter face symbol angle
p-p (110)-(110) 77°22'
Q-q (011)–(011) 84°24'
q—p (011)–(110) 65° 10'
Double refraction: Positive and very small.
o'- 1.555-H,8= 1.555-H, y = 1.555-F.
Arial plane for red: c {001}
Arial plane for blue: b {010}
The axial angle is very small and becomes zero at certain wave
lengths and temperatures so that the crystal appears uniaxial.

544
Circular of the National Bureau of Standards
12 O OIO
| | O
FIGURE 124.-Anhydrous dextrose crystal.


Polarimetry, Saccharimetry, and the Sugars 545
Figure 125,-Stereographic net of anhydrous deatrose.
-
º
º
* * *
FIGURE 126.-Goldschmidt two-circle goniometer used at the National Bureau of
Standards.


546
Circular of the National Bureau of Standards
(b) a-DEXTROSE (ANHYDROUS)
Class 6: Rhombic bisphenoidal.
Ratio of aires: a, b. c-0.704: 1:0.355 [15].
Plane of optic aris: a £100}.
Refractive indices: a = 1.530, 6–1.550, y = 1.560.
TABLE 71.--Crystal forms of anhydrous deat rose
Possible forms USual forms

m{11();
|;
Same as levulose, see page 541, Ab{010;
Table 69 m (120
{{227;
TABLE 72.-Angular values between faces of anhydrous deart rose
-
Face form Millerian face Measured
letter symbol angle
–
m–m' (110)-(110) 70° 18' i
0–77) (111)–(110) 59°47'
0-m’ (110)–(110) 80° 1'
77–77). (120)-(110) 19914'
*—m’ (227)–(110) 80° 17'

4. REFERENCES
[1] W. G. Hankel, Ann. Physik 49, 495 (1840).
[2] W. H. Miller, Trans. Cambridge Phil. Soc. 7, 209–216 (1842).
[3] E. Wolff, J. prakt. Chem. 28, 129 (1843).
[4] C. F. Rammelsberg, Handb. Kryst. Chem. (1855) and later editions.
[5] F. Rinne, Rischbiets Dissertation (Göttingen, 1885), p. 514. Z. ver, deut.
Zucker-Ind. 38, 972 (1888).
[6] F. P. Phelps, Proceedings of the Fourth Congress of the International
Society of Sugar Cane Technologists Bul. 104, San Juan, P. R. (1932).
[7] G. Vavrinecz, Z. Zuckerind. cechoslovak. Rep. 51, 39 (1926); Z. Magyar
Chemiai Folyoirat 31, 29 (1925).
| F. Becke, Tschermak’s mineralog. petrog. Mitt., p. 261 (1877).
| H. E. Merwin, Int. Crit. Tables 7, 30 (1930).
] L. Longchambon, Bul. soc. Française minealogie 45, 242 (1922).
] K. Stammer, Z. Ver. deut. Zucker-Ind. 31, 794 (1881).
] W. Schaaf, Z. Ver. deut. Zucker-Ind. 33, 699 (1883).
3] J. Bock, Z. Wer. deut. Zucker-Ind. 38, 965 (1888).
4] L. Wulf, Z. Wer. deut. Zucker-Ind. 37, 917 (1887); 38, 226.
5] F. Becke, Tschermak’s mineralog. petrog. Mitt. 2, 184 (1880); 10, 464, 495
(1889). Absts. Z. Krist. 5, 283; 20, 298 (1888).
16] M. J. Schuster, Tschermak’s mineralog. petrog. Mitt. 9, 216 (1888).
XXXIII. MELTING POINTS
1. GENERAL
The melting point is a valuable aid in the identification of purified
sugars and their derivatives and also in the determination of the
purity of these compounds. At any given pressure the solid and liquid
phases of a substance are at equilibrium at a definite temperature.
The presence of a small trace of impurity generally alters the melting
point. Some substances, however, exist in more than one crystal
Polarimetry, Saccharimetry, and the Sugars 547
form and thereby have their melting points affected by the method of
heating, thus making the melting point a less definite indication of
purity. A number of different methods have been devised for making
the melting point determination. Various types of melting point
tubes are shown in figure 127.
2. CAPILLARY-TUBE METHODS
The simplest apparatus, illustrated by No. 1, consists of a round-
bottomed tube of Pyrex or other suitable heat-resistant glass approxi-
mately 100 mm long, 30 mm inside diameter, and with walls not more
than 1.5 mm thick at any point. The stirring device consists of a
glass rod bent to form a ring at the bottom. The sample under test
is in a capillary tube about 60 mm long, 0.8 to 1.2 mm inside diameter,
with walls from 0.2 to 0.3 mm thick, and is closed at one end. In
making the determination, place the finely powdered substance in the
capillary tube by pushing the open end into the powder, and pack it
| 2 3
FIGURE 127.--Types of melting-point tubes.
down by moderate tapping on a solid surface. The sample should
form a column about 3 mm in length when packed down. Attach
the capillary to the thermometer by wetting them with the liquid of
the bath or attach them by means of a piece of fine platinum wire.
Adjust the position of the capillary so that the substance is centrally
located by the side of the thermometer bulb. As a heating bath, fill
the large tube with a suitable liquid such as sulfuric acid to a depth
which will permit the top of the thermometer bulb to be immersed
20 to 30 mm below the surface of the liquid. Stir the bath con-
stantly while heating slowly over a Bunsen flame or on an electric
heater. Retard the rate of heating as the suspected melting point
is approached, until finally the heating is so regulated that the rise in
temperature is about 0.5 degree per minute. The temperature at
which the substance liquifies is taken as the melting point.
In the method of the United States Pharmacopoeia [1] the tem-
perature at which the column of substance in the capillary tube first
begins to liquify at any point is defined as the beginning of melting,
and the temperature at which the substance becomes liquid through-

548 Circular of the National Bureau of Standards
out is defined as the end of melting. The usual precuations regarding
the heating and stirring of the bath are observed. The result thus
obtained as the melting interval is adjusted for the calibration cor-
rection of the thermometer and the correction for the emergent stem.
In this method the following liquids are suggested for use as heating
baths: For temperatures up to 200°C, pure concentrated sulfuric
acid; for temperatures up to about 350°C, a pure grade of cotton-seed
oil (almost colorless). Other, though less desirable, substitutes for
sulfuric acid at high temperatures are pure paraffin freshly distilled,
and clean, white artificial (cotton-seed) lard. A very desirable bath
for high temperature work is prepared by cautiously boiling together,
for 5 or 10 minutes under a hood, a mixture of 70 parts of purified
concentrated sulfuric acid and 30 parts of potassium sulfate, stirring
constantly until the sulfate is completely dissolved.
In place of the simple tube described above, many workers prefer
to use the Thiele melting-point tube (No. 2) or the Thiele-Dennis


\-
SIDE VIEW END VIEW
FIGURE 128.-Melting-point tube.
tube (No. 3). These tubes are so designed that heating causes a cir-
culation of the liquid in the tube, making stirring unnecessary. A
further modification (figure 128) consists of a tube similar to the above
with a side tube sealed in at an angle of about 30° to the axis of the
tube, which permits the capillary containing the sample to be inserted
or removed without removing the thermometer. The use of the side
arm also has the advantage that the capillary containing the sample
can be placed in contact with the thermometer bulb and the usual
unsatisfactory methods of fastening the capillary to the thermometer
are eliminated. The various modifications of the Thiele tube and a
discussion of their advantages are given in reference [2].
3. ADDITIONAL METHODS
Another method of determining melting points employs the Ma-
quenne Block. This consists of a block of brass mounted in a frame
above a long gas burner. In the top surface of the block are a number
Polarimetry, Saccharimetry, and the Sugars 549
of small cavities. A hole is bored lengthwise of the block, just below
its upper surface, to permit the insertion of a thermometer.
To make a melting-point determination, place a small amount of
the sample in one of the cavities and cover with a small glass plate.
Insert the thermometer so that the bulb is just under the cavity con-
taining the sample. Heat the block slowly until the substance begins
to melt, then adjust the thermometer so that the mercury column
just projects beyond the end of the block and note the temperature.
As the block has approximately a uniform temperature, the stem cor-
rection of the emergent mercury column is eliminated.
Dennis and Shelton [3] have devised an apparatus for the accurate
and rapid determination of melting points. It consists of an electric
heater controlled by a rheostat and mounted on the end of a square
pure copper bar. The temperature of this bar can be varied from room
temperature to 300° C by means of the rheostat. A voltmeter shows
the potential across the heater. The heat applied at one end of the
bar causes a temperature gradation along the length of the bar, with a
temperature variation of from 10° to 30° C. The temperature of the
bar at any point is determined by turning a knob which lowers a con-
stantan element onto the copper bar. This contact forms a thermo-
couple, the potential of which is read on a potentiometer graduated
directly in degrees centigrade. To determine the melting point of a
substance, drop a few finely ground particles along the surface of the
bar. If the bar has been heated to the proper temperature, a distinct
line of demarcation will be noted between the melted and unmelted
particles. Move the knob along its slider and lower the constantan
element onto the bar exactly at this line. Read the temperature
directly by means of the potentiometer. The apparatus is claimed
to give values for melting points to an accuracy of about 0.25° C.
4. REFERENCES
[1] U. S. Pharmacopoeia XI, p. 455–457 (Mack Printing Co., Easton, Pa., 1936).
[2] A. A. Morton, Laboratory Technique in Organic Chemistry, p. 27–30 (Mc-
Graw-Hill Publishing Co., Inc., New York, N. Y., 1938).
[3] L. M. Dennis and R. S. Shelton, J. Am. Chem. Soc. 523128 (1930).
PART 4. GENERAL INFORMATION
XXXIV. STANDARD SAMPLES
1. SU CROSE 44
This Bureau is prepared to issue standard sucrose samples (see
p. 392) prepared by recrystallization from aqueous solution or by
precipitation with alcohol. For each sample, the process of purifica-
tion has been continued until analysis shows a satisfactory product.
A certificate of analysis accompanies the sample. The sugar usually
contains but little moisture, and in a moderately dry atmosphere
shows very little hygroscopicity. Et is advisable to store the sample
in a cool, dry place. If placed in a desiccator, the drying agent used
should be pure. Vapors from impure sulfuric acid or phosphorus
pentoxide frequently damage the sugar.
The uses of standard sucrose samples may be stated briefly as
follows: (1) As a primary saccharimetric standard; (2) as a source
of pure invert sugar for the standardization of analytical determi-
nations of reducing sugar; (3) as a standard for the calibration of
viscometers; and (4) as a material for standardization of bomb
calorimeters. Sucrose has the advantage of being nonvolatile and
nonhygroscopic. It is rather difficult to ignite and sometimes does
not burn completely. It has a heat of combustion of about 3,950
calories, or only about half that of coal. The more exact value for
each sample will be given in the certificate. For details of the stand-
ardization of bomb calorimeters, see NBS Circular C11.
2. DEXTROSE 45
The standard dextrose samples are prepared by purification of the
purest glucose of commerce in the manner described on page 390. A
certificate of analysis will show the degree of purification of the sample.
The standard dextrose sample is intended to assist in research work
of a general nature and, in particular, to serve as a standard reducing
sugar for analytical work.
XXXV. TESTS
1. SPECIAL
The special requirements of scientific investigators, manufacturers
of apparatus, and others, for higher precision than is considered in the
following schedules, will be met as far as the regular work of the
Bureau will permit. The application for a special test should state
fully the purpose for which the apparatus has been used or is to be
used in the future, the need for the test, and the precision desired.
The test should be arranged for by correspondence before shipment
of the apparatus. The special fee charged will depend chiefly upon
the time consumed and the amount of alteration required in the
regular Bureau testing set-ups. An estimate will be given when
possible.
44, 45 See list on p. 550.
551
552 Circular of the National Bureau of Standards
2. GENERAL INSTRUCTIONS TO APPLICANTS FOR TESTS
(a) APPLICATION FOR TEST
The request for test should be made in writing, addressed to the
National Bureau of Standards, Washington, D. C., and should enu-
merate the articles submitted for test, giving the identification marks of
each—for example, maker's name and number—and should state the
nature of the test desired.
(b) NATURE OF TEST
The classification of tests in this Circular should be followed, and
the schedule numbers should be used to indicate the test desired.
When the desired test is not included under the regular schedules, the
applicant must comply with the requirements for special tests. When
apparatus is sent simply for test, without definite instructions, the
Bureau will, if practicable, decide upon the nature of the test.
(c) IDENTIFICATION MARKS
All packages should bear the shipper's name and address and, when
convenient, a list of the contents.
Each separate piece of apparatus or sample of material should be
provided with an identification mark, which in many cases may be
the maker's name and number. The identification mark should be
given in the application for the test.
(d) SHIPPING DIRECTIONS
Apparatus or test specimens should be securely packed in cases or
packages which will not be broken in transportation. The shipment
in both directions is at the applicant’s risk. To facilitate packing and
shipping, the tops of the cases should have the return or forwarding
address on the underside and should be put on with screws. Trans-
portation charges are payable by the party desiring the test and must
be prepaid. Unless otherwise arranged, articles will be returned or
forwarded by express collect.
(e) RETURN OF APPARATUS
Regular tests will be made in the order in which the applications
are received, except as this practice may be varied by grouping similar
tests together. It is suggested, therefore, that the applicant, if pos-
sible, make request for a test from 2 weeks to 2 months preceding the
shipment of the apparatus. This facilitates the work of the Bureau
as well as the prompt return of the apparatus.
(f) ADDRESS
Apparatus submitted for test, as well as all correspondence, should
be addressed to the National Bureau of Standards, Washington, D. C.
Apparatus delivered in person or by messenger should be accompanied
by a written request for the test.
(g) REMITTANCES
Fees should be sent with the request for test, in accordance with
the following schedules, or promptly upon receipt of bill. Certificates
are not given nor is apparatus returned until the fees due thereon have
been received. Remittances may be made by money order or check
drawn to the order of the National Bureau of Standards.
Polarimetry, Saccharimetry, and the Sugars 553
3. CERTIFICATES AND STATEMENTS
Apparatus that fulfills the requirements for certification will be
tested and given a certificate of corrections. The certificate can only
indicate the corrections of the apparatus at the time of the test and ,
does not guarantee the constancy of the values. When there are
defects which exclude an apparatus from certification, a report will be
issued instead of a certificate, in which such information as has been
found will be stated.
4, TEST-FEE SCHEDULES 46
Effective July 1, 1940, superseding all previous schedules for the items covered.
TEST FEE SCHEDULE 421.— Polariscopes for absolute measurement—Circular scales
Item Description Fee
421a || Polariscopes for absolute measurement:
Determination of true value of five to ten points + 0.01°,
with critical examination of optical parts - - - - - - - - - - - - - $7.50
421b | Polariscopes for absolute measurement:
Determination of true value of five to ten points + 0.002°,
with critical examination of optical parts- - - - - - - - - - - - 12. 50
421 c | Eliptic analyzers. Price according to precision required,
minimum charge---------------------- ... — — — — — - - - - - - - - - - 2. 00
TEST FEE SCHEDULE 422.-Elliptic analyzers and physical properties of glass
Item Description Eee
422a || Glass:
Determining the softening points and annealing ranges up
to 800° C----------------------------------------- $25. 00
422b Determining deformability up to 700° C and over a range
of not more than 50° C.---- - - - - - - - - - - - - - - - - - - - - - - - - - 60.00
TEST FEE SCHEDULE 423.−Quartz control plates and polariscope cover glasses

Items Description Fee
Quartz control plates:
423a. Certification of rotation in circular degrees, “yellow-green
mercury line’’ (X=546.1 mp) and sodium lines
(A= 589.25 mp) at 20° C____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ $3.00
423b Certification of same in circular degrees and sugar degrees
at 20° C------------------------------------------ 4. 00
423C Certification of rotation at other temperatures by special
arrangement.
423d Test of quartz control plates rejected, each (see 423y) -- - - - . 25
423e Table of sucrose corrections for temperature- - - - - - - - - - - - 2. 00
Cover glasses:
423f Absence of double refraction, each (see 423y) ----- - - - - - - - ... 10
423y Minimum total charge billed for any test - - - - - - - - - - - - - - - - - 2. 00
* For special tests not covered by these schedules, fees will be charged dependent on the nature of the test.
Copies of certificates or reports previously issued or reissue of worn or damaged certificates or reports
returned, each 25 cents; minimum fee, $1,00,
554
Circular of the National Bureau of Standards
TEST FEE SCHEDULE 424.—Saccharimeters
Item Description Fee
|
Single quartz wedge:
424a Certification at five points - - - - - - - - - - - - - - - - - - - - - - - - - - - $6. 50
424b Adjustment and certification at five points_-_ _ _ _ _ _ _ _ _ _ _ _ 12. 50
to 35. 00
Double quartz wedge:
424C Certification at five points on positive wedge and three
points on negative wedge - - - - - - - - - - - - - - - - - - - - - - - - - - - 9. O0
424d Certification at five points on each wedge_-- - - - - - - - - - - - - 10. 00
424e Adjustment and certification at five points for each wedge- 15. 00
to 35. 00
Laurent type: -
424f Certification at five points - - - - - - - - - - - - - - - - - - - - - - - - - - 7. 50
Other types:
424g Certification at price according to condition.
TEST FEE SCHEDULE 425.-Sugars and other materials
Item Description Fee
|
Raw sugars and molasses:
4.25a Direct polarization---- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - : $3.00
425b Clerget polarization by acid inversion - - - - - - - - - - - - - - - -- 5. 00
Raw sugars:
425c Clerget polarization by invertase - - - - - - - - - - - - - - - - - - - - - - 6. 00
425Cl Polarization at 87° C_____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 6. 00
Reducing sugars: }
425e Determination of - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4. 00
Sugar:
425f Moisture determination – - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2. 00
425g Ash determination -- - - - - - - - - - - - - - - - - - - - - - - - - - - - --- - - - - 3. 00
Molasses:
425h Determination of specific gravity or weight per gallon - - - 4. 00
425i Determination of moisture - - - - - - - - - - - - - - - - - - - - - - - - - - - 4. 00
425z | Determination of purity of purified sucrose, dextrose, and
other sugars; optical rotation for any substance; or for
special tests not covered by the above schedule, fees will be
charged dependent upon the nature of the test.
TEST FEE SCHEDULE 311 (ExTRACT).-Laboratory thermometers
Item Description Fee
3.11a | Thermometers, testing at points in the interval 0° to 100°C
(32° to 212° F) for each point tested_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ $0.50
3.11b | Thermometers, testing at points above 100° and up to 300°
C, or above 212° and up to 600°F, for each point tested - . 75
3.11c | Thermometers, testing at points above 300° C or above 600°
F, for each point tested-------- - - - - - - - - - - - - - - - - - - - - - - - 2. 00
3.11d Thermometers, testing at points in the interval 0° to — 35°C
or 32° to -35° F, for each point tested_____ _ _ _ _ _ _ _ _ _ _ _ _ 2. 50
Items (a) to (d), inclusive, apply particularly to the types
of thermometers listed in tables 1, 2, 3, and 4 of Bureau
Circular C8, 3d or 4th ed. .
311e Calorimetric thermometers, testing at intervals of 2°C or 5° F- 5. 00
311 f | Beckmann thermometers, with 5° or 6° C scale, testing at 1°
intervals by comparison with precision standards_ _ _ _ _ _ _ _ 6. 00
Polarimetry, Saccharimetry, and the Sugars
555
TEST FEE SCHEDULE 311 (ExTRACT).-Laboratory thermometers—Continued
Item Description Fee
311 ff Beckmann thermometers, calibration by means of mercury
threads and comparison with precision standards, with the
highest accuracy warranted by the construction and
action of the thermometer----------------------------- $12. 00
Unless the request for test of a Beckmann thermometer speci-
fies test under 311ff, the instrument will be tested under
item 311f. Thermometers so constructed that unusual
difficulty is encountered in separating mercury threads for
calibration will be eligible for test only under item 311 f.
There is somewhat greater danger of breakage in tests
under 311ff than in tests under 311f. Beckmann ther-
mometers with scales longer than 6° will be subject to
special fees.
311j | Thermocouples for temperatures between –40° and 500°C
minimum charge each-------------------------------- 10. 00
311k | Thermocouples for range – 40° to 500° C, calibration per
point----------------------------------------------- 3. 00
Items (j) and (k) do not cover tests of multiple junction as-
semblies.
Items (g) to (k), inclusive, refer to tests described in National
Bureau of Standards Circular C8, 3d or 4th ed.
31.1m | When instruments submitted are found by preliminary tests
to be unsuitable for test, a charge will be made to cover
the cost of the preliminary work. Minimum fee- - - - - - - - 1. O0
3.11y | Minimum fee on any test or transaction - - - - - - - - - - - - - - - - - - 1. 00
TEST FEE SCHEDULE 2.97.-Polariscope Tubes
Item Description |Fee
297c Polariscope tubes—
Determination of the average length of a polariscope ob-
servation tube and marking with NBS serial number if
| length is within +0.04 mm of the nominal value:
(1) 100-mm tubes, each -- - - - - - - - - - - - - - - - - - - - - - - - - $1.00
(2) 200-mm tubes, each - - - - - - - - - - - - - - - - - - - - - - - - - - 1. 00
(3) 400-mm tubes, each - - - - - - - - - - - - - - - - - - - - - - - - - - 2. 00
297d | Same, when four or more of the same size are submitted at
the same time:
(1) 100-mm tubes, each - - - - - - - - - - - - - - - - - - - - - - - - - - . 75
(2) 200-mm tubes, each - - - - - - - - - - - - - - - - - - - - - - - - - - . 75
(3) 400-mm tubes, each - - - - - - - - - - - - - - - - - - - - - - - - - - 1. 50
297e Polariscope tubes—
| Determination of average length of 100 and 200 mm polar-
iscope observation tubes to + 0.01 mm
| (1) 100-mm tubes, each - - - - - - - - - - - - - - - - - - - - - - - - - - 1. 50
(2) 200-mm tubes, each - - - - - - - - - - - - - - - - - - - - - - - - - - 2. 00
297f Same, when four or more of the same size are submitted at
the same time:
(1) 100-mm tubes, each - - - - - - - - - - - - - - - - - - - - - - - - - - 1. 15
(2) 200 mm tubes, each - - - - - - - - - - - - - - - - - - - - - - - - - - 1. 50
297g Polariscope tubes—
Determination of average length of 400 mm polariscope
observation tube to + 0.02 mm, each -- - - - - - - - - - - - - - - - 3. 00
297h | Same, when four or more are submitted at the same time,
each----------------------------------------------- 2. 25
297 y |Minimum total charge billed for any test -- - - - - - - - - - - - - - - - 2. 00
556
Circular of the National Bureau of Standards
TEST FEE SCHEDULE 225.-“Class M” laboratory standards of mass
[NotE.-Item b applies to weights which are boiled in distilled water to remove traces of plating salts as
completely as possible, and also as a test of the adequacy of the plating. Item a applies to weights which
are not given this treatment, particularly to those that are not electro
years.]
plated or that have been in use for SOme
Item
Description
Fee
225a.
225b
2.25d
225;
225 V.
225W
Class M standards that are not new or not plated: For each
set, or single weight, or group that is submitted, tested
and certified or reported as a unit—
For regular inspection, cleaning, handling, etc. (but not
including test for accuracy) - - - - - - - - - - - - - - - - - - - - - - -
New plated class M standards and sets or groups containing
such standards: For each set, or single weight, or group
of weights that is submitted, tested, and certified or re-
ported as a unit—
For regular inspection, cleaning, handling, etc. (but not
including test for accuracy) - - - - - - - - - - - - - - - - - - - - - - -
(Note.—To the appropriate item above there will be added,
in the case of a full regular test, an amount computed
from one or more of the following items—the item or items
used depending on the nature of the test.
For weights given the complete inspection, cleaning, etc. but
not tested for accuracy, on account of defects discovered
or for some other cause, the fee is only the appropriate one
of the items above.)
Moderate precision test of each weight—
Testing accuracy and certifying or reporting of correction
for each weight---------------------------------...--
High precision test of each weight—
Testing accuracy and certifying or reporting of correction
for each weight (as a rule this test requires also the
determination of the volume of each weight above I g.
See item V)---------------------------------------
For each weight for which the actual volume must be deter-
mined—
Determination of actual volume by hydrostatic weigh-
long period of time must be assured—
Determination of change that occurs during 3 months
under good atmospheric conditions. The fee for this
test of constancy with “age” will be equal to (and in
addition to) that computed from item d or j.
$1, 00
2. 00
. 75
Minimum total charge billed for any test- - - - - - - - - - - - - - - - -
Polarimetry, Saccharimetry, and the Sugars
557
TEST FEE SCHEDULE 226.-‘‘Class S” laboratory weights
Item
Description
Fee
226a.
226b
226Cl
226g
Class S laboratory weights that are “one-piece” weights,
or screw knob weights that are not plated or lacquered, or
in general, weights that do not need to be given a test for
the effect of changes in atmospheric humidity: For each
set or single weight, or group that is submitted, tested and
certified or reported as a unit—
For regular inspection, cleaning, handling, etc. (but not
including test for accuracy) - - - - - - - - - - - - - - - - - - - - - - -
Plated or lacquered screw knob weights or sets or groups that
include such weights; or in general, weights that are tested
for the effect of variations in atmospheric humidity:
For each set, or single weight, or group that is submitted
tested and certified or reported as a unit—
For regular inspection, cleaning, handling, etc. (but
not including test for accuracy) - - - - - - - - - - - - -- - -
[NOTE.--To the appropriate item above there will be
added, in the case of a full regular test, an amount com-
puted from either item d or item g depending on the na-
ture of the test.
For weights given the complete inspection, cleaning,
etc., but not tested for accuracy, on account of defects dis-
covered or for some other cause, the fee is only the appro-
priate one of the items above.]
Determination of actual value for each weight—
Testing and certifying or reporting of actual correction
for each weight------------------------------------
Tolerance test of each weight—
Testing and certifying or reporting whether each weight
is correct within the specified tolerance- - - - - - - - - - - - - - - - -
$1.00
3. 00
. 75
. 40
226)
Minimum total charge billed for any test - - - - - - - - - - - - - - - -
TEST FEE SCHEDULE 227. —“Class S2’’ laboratory weights
This schedule covers a new class, including what are often called “second
quality analytical weights,” “students' sets,
’’ and other laboratory weights of
similar quality and of accuracy within five times the tolerances for weights of
class S.
Item
Description
Fee
227a.
227g
227y
Class S2 laboratory weights, for each set or single weight, or
group that is submitted, tested, and certified or reported
as a unit—
For regular inspection, cleaning, handling, etc. (but not
including tests for accuracy) - - - - - - - - - - - - - - - - - - - - - - - -
[NOTE.—To the item above there will be added, in the
case of a full regular test, an amount computed from item g.
For weights given the complete inspection, cleaning, etc.,
but not tested for accuracy, on account of defects discovered
or for some other cause, the fee is only item a.]
Tolerance test of each weight— -
Testing and certifying or reporting whether each weight
is correct within the specified tolerance- - - - - - - - - - - - -- - -
Minimum total charge billed for any test - - - - - - - - - - - - - - - - -
$1.00
. 30
2. 00
323414°—42—37
558
Circular of the National Bureau of Standards
TEST FEE SCHEDULE 241 (extract). —Volumetric apparatus
Item Description Fee
241 a | Flasks of capacities up to and including 250 ml–-
Testing and stamping, each flask - - - - - - - - - - - - - - - - - - - - - $0. 40
241b | Flasks of capacities above 250 ml–
Testing and stamping, each capacity tested - - - - - - - - - - . . . . 75
241c | Transfer pipettes and Babcock test bottles—-
Testing and stamping, each capacity tested - - - - - - - - - - - - - . 50
241 d Cylindrical graduates—
Testing and stamping, each interval tested - - - - - - - - - - - - . 40
24le | Specific gravity flasks—
Testing and stamping, each capacity tested - - - - - . . . . . . . 40
241 f | Certificates of capacity for any of above, when requested,
additional, each - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - . 60
(In general, certificates are not issued for the above.)
241 g | Burettes—
Testing and certifying five intervals - - - - - - - - - - - - - - - - - - 2. 50
241h Measuring pipettes—
Testing and certifying five intervals - - - - - - - - - - - - - - - - - - 2. 25
24li Burettes and measuring pipettes—-
Testing and certifying capacity of additional intervals,
each additional interval - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - . 40
241 l Apparatus intended for temperatures other than 20° C, be-
tween 15° and 30° C–
Testing, additional charge for each piece - - - . . . . . . . . . . . . . . 25
241 m Apparatus of indicated capacity other than in milliliters—-
Testing, additional charge for each piece . . . - - - - - - - - - - - - - - . 25
241n Apparatus disqualified for test—-
Preliminary examination, charge for each piece - - - - - - . 20
2410 Missing identification numbers—
For supplying, charge for each number - - - - - - -- - - - - - - - - - - . 25
24ly Minimum total charge billed for any test - - - - - - - - - - - - - . . . 2. 00
TEST FEE SCHEDULE 243 (extract). —Hydrometers and thermohydrometers
Item Description Fee
243a | Hydrometer—
Test to determine whether or not it complies with Bureau
requirements for precision stamp - - - - - - - - - . . . . . . . . . . $ 1, 50
243b | Thermohydrometer, as under (a)—-
Test including test of thermometer scale - - - - - - - - - - - - - - - - 2, 25
243c | Corrections—
Certification at three points on either or both scales, addi-
tional fee - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - . 60
243d Additional points certified, each - - - - - - - - - - - - - - - - - - - - - - - - - , 50
243e Instrument—
Determination of weight, additional fee- - - - - - - - - - - - - - - - . . 50
243f Missing identification numbers—
supplying, charges per number- - - - - - - - - - - - - - - - - - - - - - - . . 25
Polarimetry, Saccharimetry, and the Sugars
Standard sugar samples
Stand-
sº€ Description Fee
No.
17 | Sucrose-------------------------------------- 60 grams $2.00
41 | Dextrose------ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 70 grams 2. 00
PART 5.—APPENDIXES
561
XXXVI. APPENDIX 1.—TABLES 73 TO 150
[Additional literature references to accompany some of the tables are given on
page 693.]
TABLE 73.-Formulas for calculating specific rotations (concentration variable)
C = Concentration in grams per 100 ml.
p = percentage by weight.
q = percentage of water.
Sugar Formula
Sucrose_ _ _ ! . . . . . . . . . . |o]}=66.462--0.0087c=0.000235c. [1].
Dextrose_ _ _ _ _ _ _ _ _ _ _ _ off-52.50+0.0188p––0.000517p3.
Dextrose . . . . . . . . . . . oftºna = 62.032+0.04257c [2].
Dextrose- oftºn A-62.032-1-0.04220p H-0.0001897p” [2].
Fructose- - - - - - - - - - - - - |o]}} = — 113.96–H 0.258q.
Maltose-- - - - - - - - - - - - - |o]}}=138.475–0.01837.p.
Lactose- - - - - - - - - - - - - |o]} = 52.53.
Invert sugar - . . . . . . [a]}= — (19.415+0.070650–0.00054c”) [3].
Invert sugar tempera-
ture correction-- - - - - | [o], -[o]}}+ (0.283–H 0.0014c) (t–20°C) [3].
REFERENCES
[1] This Circular, p. 82.
[2] R. F. Jackson, Bul. BS 13, 633 (1916) S293.
[3] F. W. Zerban, J. Am. Chem. Soc. 47, 1104 (1925).
TABLE 74.—Rotatory power of deactrose and corrections to be applied to saccharimeter
readings 1
e Rotation t Rotation
Scale Correction Scale Correction
reading toºdied P..." reading toº added|P."
C S C S O S o S C. S o S
100 () 3. 1026 50 0. 55 3.0688
95 , 10 3.0993 45 . 54 3.0658
90 . 20 3. 0957 40 . 53 3.0621
85 . 28 3.0924 35 . 50 3. 0589
80 . 35 3.0890 30 . 46 3. 0.559
75 . 41 3. 0.858 25 . 41 3. 0525
70 . 46 3.08.23 20 . 35 3.0492
65 . 50 3.0790 15 . 28 3. 0457
60 . 525 3.0757 10 . 20 3.0414
55 . 54 3. 0725 5 . 10 3.0414
- - - - - - - " - - - - - - - - - - - - - - - - 2 . 05 3.0257

! Based on the normal weight 32.231 g (air, brass weights) at 20° C.
(1916) S293.
562
R.
F. Jackson, Bul. BS 13, 36
Polarimetry, Saccharimetry, and the Sugars
563
TABLE 75.-Specific rotation ([o]}) of certain sugars at various concentrations
º Sucrose Dextrose | Fructose Maltose Lactose hydrate
ration
| % % % % %
5 66. 500 52. 607 –89. 42 138. 38 52.53.
10 66. 527 52. 740 –90. 72 138. 29
15 66. 541 52. 898 –92. 01 138. 20
20 66. 540 53. 083 –93. 30 138. 11
25 66. 523 53. 293 –94. 59 138. 02 Remains unchanged at all
concentrations.
30 66. 487 53.529 –95. 88 137. 92
35 66.432 53. 791 –97. 18 137.82
40 66. 351 54.079 –98. 47 | - - - - - - - -
45 66. 245 54. 393 | - - - - - - - || - - - - - - - -
50 66. 109 54. 732 || ------- || --------
TABLE 76.-Rotatory power of invert sugar'
º e Rotation of in- Y , , ; & Rotation of in-
Wºn [o]% vert Sugar per Wºn [a]% vert sugar per
gram at 20°C gram at 20°C
g degrees oS g degree8 o S
| — 19. 693 — 1. 1377 14 –20, 162 — 1. 1648
2 l 19. 729 1 1. 1397 16 1 20, 235 1 1. 1690
4 1 19. 801 1 1. 1439 18 120. 307 1 1. 1731
6 1 19.874 | 1. 1481 20 I 20. 379 1 1. 1773
8 l 19.946 1 1. 1523 22 120. 451 1 1. 1815
I () | 20.018 1 1. 1564 24 1 20, 523 I 1. 1856
12 120. 090 l 1, 1606 26 120. 596 1 1. 1898

I Calculated from Gubb's equation.
Ber. deut. Chem. Ges. 18, 2207 (1885).
TABLE 77.--Coefficients in the Creydt raffinose formula
P– S
S
a P-b P'
bc
• R
T.852'
[If both polarizations have the same temperature, use column be.
If polarized
at different temperatures, multiply b at ti (of direct polarization) by c at t2 (of
invert polarization). To the whole denominator, add 0.000794 (m – 13), in which
m is the dry substance taken for inversion and contained in a final volume of
100 ml].
Basic Clerget divisor
Raffi-
* - 3. O g tº Y iſ DOS6
Temperature (°C) 133. 00 133. 18 133. 29 denom-
inator
(l b C bc C bc C bc
16 -------------------------- 0. 5068 || 1. 0012 || 0.8568 0.8578 0.8586 0.8596 || 0.8597 || 0.8607 1. 854
17--------------------------- . 5086 | 1.0009 | . 8536 | . 8544 | . 8554 . 8562 . 8565 . 8573 1. 854
18--------------------------- . 5104 || 1.0006 | . 8504 | . 8509 | . 8522 . 85.27 . 8533 | . 8538 1. 853
19--------------------------- , 5122 | 1.0003 | . 8472 | . 8475 | . 8490 . 8493 . 8501 . 8504 1.853
20--------------------------- . 5140 | 1.0000 | . 8440 | . 8440 | . 8458 . 8458 . 8469 . 8469 1.852
21--------------------------- . 5158 0.9997 | . 8408 . 8406 | . 8426 . 8423 .8437 .8434 1.851
22--------------------------- . 5176 . 9994 | . 8376 . 8371 . 8394 | . 8389 . 8405 | . 8400 1. 851
23--------------------------- . 5194 . 99.91 . 8344 . 8337 . 8362 | . 8354 . 8373 . 8365 1. 850
24--------------------------- . 5212 . 9988 | . 8312 | . 8302 | . 8330 | . 8320 | . 8341 . 8331 1. 850
25--------------------------- . 5230 .9985 . 8280 | . 8268 . 8298 | . 8286 . 8309 . 8297 1. 849
26--------------------------- . 5248 . 99.82 | . 8248 . 8233 . 8266 | . 8251 . 8277 , 8262 1. 849
27--------------------------- . 5266 . 9979 | . 8216 . 8.199 | . 8234 | . 8217 . 8245 . 8228 1. 848
28--------------------------- . 5284 . 9976 .. 8184 . 8164 . 8202 | . 8182 . 8213 , 8193 1. 848
29--------------------------- . 5302 . 9973 | . 8152 ... 8130 | . 81.70 | . 8148 8181 , 8159 1. 847
30--------------------------- . 5320 . 99.70 | . 8120 | . 8096 | . 8138 | . 8114 81.49 | . 8125 1. 846
1 See p. 143 of text.
564
Circular of the National Bureau of Standards
TABLE 78.-Reducing-sugar values by the Munson and Walker method
[The original values of Munson and Walker 1 have been redetermined and the
values in this table for dextrose, invert sugar, and the sucrose and invert-sugar
mixtures totaling 0.4 and 2.0 g are the values redetermined by Hammond.”
The values for levulose and the 0.3–g total-sugar mixture of sucrose and invert
sugar are new values determined by Hammond.”
The values for lactose and
the two lactose and sucrose mixtures are those of Straughn and Given,” which
have been calculated to even intervals of copper.
those determined by Walker 4]
The values for maltose are
Values of National Bureau of Standards (Hammond) 5
Invert Sugar and Sucrose
Cuprous Invert
Copper oxide DextroSe Sugar Levulose
0.3 g of total 0.4 g of total 2.0 g of total
Sugar Sugar Sugar
Trig Tng Tng Tng Tng Tng mg Tng
10 11. 3 4. 6 5. 2 3. 2 2.9 |_ _ _ _ _ _ _ _ _ 5. 1
11 12. 4 5. 1 5. 7 3. 7 3. 4 - - - - - - - - - 5. 6
12 13. 5 5. 6 6. 2 4. 2 3. 9 |- - - - - - - - - 6. 1
13 14. 6 6. 0 6, 7 4, 8 4. 4 || -- - - - - - 6. 7
I 4 15. 8 6. 5 7. 2 5. 3 4. 9 |_ _ _ _ _ _ _ _ _ 7. 2
15 16. 9 7. () 7.7 5. 8 5. 4 ||--------- 7.7
16 18. 0 7. 5 8, 2 6. 3 5. 9 || - - - - - - - - 8. 3
17 19. 1 8. 0 8. 7 6, 8 6. 4 |_ _ _ _ _ _ _ _ _ 8. 8
18 20. 3 8. 5 9. 2 7. 3 6. 9 |_ _ _ _ _ _ _ _ _ 9. 3
19 21. 4 8. 9 9. 7 7. 8 7. 4 |--------- 9. 9
20 22. 5 9. 4 10. 2 8. 3 7. 9 1. 9 10. 4
21 23. 6 9. 9 10. 7 8. 8 8. 4 2. 4 10. 9
22 24, 8 10, 4 11. 2 9. 3 8. 9 2. 9 11. 5
23 25. 9 10. 9 11. 7 9. 9 9. 5 3. 4 12. 0
24 27. 0 11. 4 12. 3 10. 4 10. 0 3. 9 12. 5
25 28. I 11. 9 12. 8 10. 9 10. 5 4. 4 13. ]
26 29. 3 12. 3 13. 3 11. 4 11. 0 4. 9 13. 6
27 30. 4 12. 8 13. 8 11. 9 11. 5 5. 5 14. 2
28 31. 5 13. 3 14. 3 12. 4 12. 0 6. 0 14. 7
29 32. 6 13. 8 14. 8 12. 9 12. 5 6. 5 15. 2
30 33. 8 14. 3 15. 3 13. 4 13. 0 7. 0 15. 8
31 34. 9 14, 8 15. 8 14. 0 13. 5 7. 5 16. 3
32 36. 0 15. 3 16. 3 14. 5 14. 1 8. 0 16, 8
33 37. 2 15. 7 16. 8 15. 0 14. 6 8. 5 17. 4
34 38. 3 16. 2 17. 3 15. 5 15. 1 9. O 17. 9
35 39. 4 16. 7 17. 8 16. 0 15. 6 9. 5 18. 4
36 40. 5 17. 2 18. 3 16. 5 16. 1 10. 1 19. 0
37 41. 7 17, 7 18, 9 17. 0 16. 6 10. 6 19. 5
38 42. 8 18. 2 19. 4 17. 6 17. 1 11. 1 20. 1
39 43. 9 18. 7 19. 9 18. 1 17. 6 11. 6 20. 6
40 45. 0 19. 2 20.4 18. 6 18, 2 12. 1 21. 1
41 46. 2 19. 7 20. 9 19. 1 18. 7 12. 6 21. 7
42 47. 3 20. 1 21. 4 19. 6 19. 2 13. 1 22. 2
43 48. 4 20. 6 21. 9 20. 1 19. 7 13. 7 22. 8
44 49. 5 21. 1 22. 4 20. 7 20. 2 14. 2 23. 3
45 50. 7 21. 6 22. 9 21. 2 20. 7 14. 7 23. 8
46 51. 8 22. 1 23. 5 21. 7 21. 3 15. 2 24. 4
47 52. 9 22. 6 24. 0 22. 2 21. 8 15. 7 24. 9
48 54. 0 23. 1 24. 5 22. 7 22. 3 16. 2 25.4
49 55. 2 23. 6 25. 0 23. 2 22. 8 16. 8 26. 0
See footnotes at end of table.
Polarimetry, Saccharimetry, and the Sugars
565
TABLE 78.—Reducing-sugar values by the Munson and Walker method—Continued
[The original values of Munson and Walker have been redetermined and the
values in this table for dextrose, invert sugar, and the sucrose and invert-sugar
mixtures totaling 0.4 and 2.0 g are the values redetermined by Hammond.”
The values for levulose and the 0.3–g total-sugar mixture of sucrose and invert
The values for lactose and
the two lactose and sucrose mixtures are those of Straughn and Given,” which
The values for maltose are
sugar are new values determined by Hammond.”
have been calculated to even intervals of copper.
those determined by Walker *]
Values of Straughn and Given
Values of
Walker
Lactose.H2O and Sucrose
Copper Cuprous oxide Lactose.H2O Maltose, H2O
1 lactose 1 lactose
4 SucroSe 12 SucroSe
TIt 770 770, 770 'mg 77)
* 10 fl. 3 "7, 1 " 6, 9 -- " ---- * 7.2
11 12. 4 7. 8 7, 5 - - - - - - - - - - - - - - 8, 2
12 13. 5 8. 5 8. 2 |-------------- 9. 1
13 14. 6 9. 2 8. 9 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ 10. 1
14 15. 8 9. 9 9. 6 - - - - - - - - - - - - - - 11. 0
15 16. 9 10. 6 10. 2 || - - - - - - - - - - - - - 11. 9
16 18. 0 11. 3 10. 9 |_ _ _ _ _ _ _ _ _ _ _ _ . . 12. 9
17 19. 1 12. 0 11. 6 - - - - - - - - - - - - - - 13. 8
18 20. 3 12. 7 12. 3 - - - - - - - - - - - - - - 14. 8
19 21. 4 13. 4 12. 9 |- - - - - - - - - - - - - - 15. 7
20 22. 5 14. 1 13. 6 || - - - - - - - - - - - - - 16. 7
21 23. 6 14. 8 14. 3 || - - - - - - - - - - - - 17. 6
22 24. 8 15. 5 15. 0 |.. - - - - - - - - - - - - 18. 5
23 25. 9 16. 2 15. 7 |_ _ _ _ _ _ _ _ _ _ _ _ . . 19. 5
24 27. 0 16. 9 16. 4 || - - - - - - - - - - - - 20. 4
25 28. 1 17. 6 17. 1 || - - - - - - - - - - - - - - 21. 4
26 29. 3 18. 4 17. 8 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ 22. 3
27 30. 4 19. 1 18. 4 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ 23. 2
28 31. 5 19. 8 19. 1 |- - - - - - - - - - - - - - 24. 2
29 32, 6 20. 5 19.8 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ 25. J
30 33. 8 21. 2 20. 5 |- - - - - - - - - - - - - - 26. 0
31 34. 9 22. 0 21. 3 |- - - - - - - - - - - - - - 27. 0
32 36. 0 22. 8 22. 0 |- - - - - - - - - - - - - - 27. 9
33 37. 2 23. 6 22.8 |- - - - - - - - - - - - - - 28. 9
34 38. 3 24. 3 23.5 - - - - - - - - - - - - - - 29. 8
35 39, 4 25. 1 24, 3 |- - - - - - - - - - - - - - 30. 8
36 40. 5 25. 9 25. 0 |- - - - - - - - - - - - - - 31. 7
37 41. 7 26. 6 25. 7 |- - - - - - - - - - - - - - 32. 7
38 42. 8 27. 4 26. 5 |- - - - - - - - - - - - - - 33. 6
39 43. 9 28. 2 27. 2 - - - - - - - - - - - - - - 34. 5
40 45. 0 28. 9 28. 0 |- - - - - - - - - - - - - - 35. 5
41 46. 2 29. 7 28. 7 - - - - - - - - - - - - - - 36. 4
42 47. 3 30. 5 29. 5 || - - - - - - - - - - - - - 37. 3
43 48. 4 31. 3 30, 2 - - - - - - - - - - - - - - 38. 3
44 49. 5 32. 0 31. 0 |- - - - - - - - - - - - - - 39. 2
45 50. 7 32. 8 31. 7 - - - - - - - - - - - - - - 40. 1
46 51. 8 33. 5 32. 5 |- - - - - - - - - - - - - - 41. 0
47 52. 9 34. 3 33. 2 - - - - - - - - - - - - - - 42. 0
48 54. 0 35. 1 34. 0 |- - - - - - - - - - - - - - 42. 9
49 55. 2 35, 9 34. 7 - - - - - - - - - - - - - - 43. 8
566 Circular of the National Bureau of Standards
TABLE 78.-Reducing-sugar values by the Munson and Walker method—Continued
Values of National Bureau of Standards (Hammond)
Invert Sugar and Sucrose
Cuprous Invert |
Copper oxide Dextrose Sugar - Levulose
- 0.3 g of total 0.4 g of total 2.0 g of total
Sugar Sugar Sugar
Truſ] 'mg mug Illg ing | mg Tng Tng
50 56. 3 24. 1 25. 5 23. 8 23. 3 17. 3 26. 5
51 57. 4 24. 6 26. 0 24. 3 23. 8 17. 8 27. 1
52 58. 5 25. 1 26. 5 24. 8 24. 3 18. 3 27. 6
53 59. 7 25. 6 27. 0 25. 3 24. 9 18. 8 28. 2
54 60. 8 26. 1 27. 6 25. 8 25. 4 19. 3 28. 7
55 61. 9 26. 5 28. 1 26. 3 25. 9 19. 9 29. 2
56 63. 0 27. 0 28. 6 26. 9 26.4 20. 4 29. 8
57 64. 2 27. 5 29. 1 27. 4 26. 9 20. 9 30. 3
58 65. 3 28. 0 29. 6 27. 9 27. 5 21. 4 30. 9
59 66.4 28. 5 30. 1 28. 4 28. 0 21. 9 31.4
60 67. 6 29. 0 30. 6 28. 9 28. 5 22. 5 31. 9
61 68. 7 29. 5 31. 2 29. 5 29. 0 23. 0 32. 5
62 69. 8 30. 0 31, 7 30. 0 29. 5 23. 5 33. 0
63 70. 9 30. 5 32. 2 30. 5 30. 1 24. 0 33. 6
64 72. 1 31. 0 32. 7 31. 0 30. 6 24. 5 34. 1
65 73. 2 31. 5 33. 2 31. 6 31. 1 25. 1 34. 7
66 74. 3 32. 0 33. 7 32. 1 31. 6 25. 6 35. 2
67 75. 4 32. 5 34. 3 32. 6 32. 1 26. I 35. 8
68 76. 6 33. 0 34. 8 33. 1 32. 7 26. 6 36. 3
69 77.7 33. 5 35. 3 33. 6 33. 2 27, 1 36. 8
70 78. 8 34. 0 35. 8 34. 2 33. 7 27, 7 37. 4
71 79. 9 34. 5 36. 3 34. 7 34. 2 28, 2 37. 9
72 81. 1 35. 0 36. 8 35. 2 34. 7 28. 7 38. 5
73 82. 2 35. 5 37. 4 35. 7 35. 3 29. 2 39. ()
74 83. 3 36. 0 37. 9 36. 3 35. 8 29. 8 39. 6
75 84.4 36. 5 38. 4 36. 8 36. 3 30. 3 40. 1
76 85. 6 37. 0 38. 9 37. 3 36. 8 30. 8 40. 7
77 86. 7 37. 5 39. 4 37. 8 37.4 31. 3 41. 2
78 87. 8 38. 0 40. 0 38.4 37. 9 31. 9 41. 7
79 88. 9 38. 5 40. 5 38. 9 38.4 32.4 42. 3
80 90. 1 39. 0 41. 0 39. 4 38. 9 32. 9 42. 8
81 91. 2 39. 5 41. 5 39. 9 39. 5 33. 4 43.4
82 92. 3 40. 0 42. 0 40. 5 40. 0 34. 0 43. 9
83 93.4 40. 5 42. 6 41. 0 40. 5 34. 5 44. 5
84 94. 6 41. 0 43. 1 41. 5 41. 0 35. 0 45. 0
85 95. 7 41. 5 43. 6 42. 0 41. 6 35. 5 45. 6
86 96. 8 42. 0 44. 1 42. 6 42. 1 36. 1 46. 1
87 97. 9 42. 5 44. 7 43. 1 42. 6 36. 6 46. 7
88 99. 1 43. 0 45. 2 43. 6 43. 1 37. 1 47. 2
89 100. 2 43. 5 45. 7 44. 1 43. 7 37. 6 47. 8
90 101. 3 44. 0 46. 2 44. 7 44. 2 38. 2 48. 3
91 102. 5 44. 5 46. 7 45. 2 44. 7 38. 7 48. 9
92 103. 6 45. 0 47. 3 45. 7 45. 2 39. 2 49. 4
93 104. 7 45. 5 47. 8 46. 3 45. 8 39. 8 50. 0
94 105. 8 46. 0 48. 3 46. 8 46. 3 40. 3 50. 5
See footnotes at end of table.
Polarimetry, Saccharimetry, and the Sugars
567
TABLE 78.-Reducing-sugar values by the Munson and Walker method—Continued
Values of Straughn and Given
Walker
Values of
Copper
Cuprous oxide
Lactose. H2O
LactoSe.H2O and Sucrose
Maltose. H2O
1 lactose 1 lactose
4 SucroSe 12 SucroSe
Tng ing Ing ng mg mg
50 56. 3 36. 6 35. 5 |. . . . . . . . . . . . . . 44. 8
51 57. 4 37. 4 36. 2 - - - - - - - - - - - - - - 45. 7
52 58. 5 38. 2 37. 0 |_ _ _ _ _ _ _ _ _ _ _ _ _ . 46. 7
53 59. 7 39. 0 37. 7 - - - - - - - - - - - - - - 47. 6
54 60. 8 39. 7 38.5 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ 48. 6
55 61. 9 40.4 39. 2 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ 49. 5
56 63. 0 41. 2 40. 0 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ 50. 4
57 64. 2 42. 0 40. 7 |- - - - - - - - - - - - - - 51. 4
58 65. 3 42. 8 41. 5 39. 0 52. 3
59 66. 4 43. 6 42. 2 39. 7 53. 2
60 67. 6 44. 4 43. 0 40. 5 54. 2
61 68. 7 45. 1 43. 7 4.1. 1 55. 2
62 69. 8 45. 9 44. 5 4.1. 8 56. 1
63 70. 9 46. 7 45. 2 42. 4 57. 1
64 72. I 47. 4 46. () 43. 1 58. 0
65 73. 2 48. 2 46. 7 43. 8 58. 9
66 74. 3 49. 0 47. 5 44. 4 59. 9
67 75. 4 49. 7 48. 2 45. 1 60. 8
68 76. 6 50. 5 49. 0 45. 7 61. 8
69 77.7 51.3 49. 7 46.4 62. 7
70 78. 8 52. 1 50. 5 47. 1 63. 7
71 79. 9 52. 8 51. 2 47. 7 64. 6
72 81. 1 53. 6 52. 0 48. 4 65. 5
73 82. 2 54. 3 52. 7 49. 1 66. 5
74 83. 3 55. 1 53. 5 49. 7 67. 4
75 84.4 55. 9 54. 2 50. 4 68. 4
76 85. 6 56. 7 55. 0 51. 0 69. 3
77 86. 7 57. 5 55. 7 51. 7 70. 2
78 87. 8 58. 2 56. 5 52.4 71. 2
79 88. 9 59. 0 57. 2 53. 1 72. 1
80 90. 1 59. 8 58. 0 53. 8 73. 1
81 91. 2 60. 5 58. 7 54. 4 74. 0
82 92. 3 61. 3 59. 5 55. 1 74. 9
83 93. 4 62. 1 60. 2 55. 7 75. 9
84 94. 6 62. 9 61. 0 56. 4 76. 8
85 95. 7 63. 6 61. 7 57. 0 77. 8
86 96. 8 64.4 62. 5 57. 7 78. 7
87 97. 9 65. 2 63. 2 58. 4 79. 6
88 99. 1 66. 0 64. 0 59. 1 80. 6
89 100. 2 66. 7 64. 7 59. 7 81. 5
90 101. 3 67. 5 65. 5 60. 4 82. 5
91 102. 5 68. 3 66. 3 61. 1 83. 4
92 103. 6 69. 1 67. 0 61. 8 84. 3
93 104. 7 69. 8 67. 8 62. 4 85. 3
94 105. 8 70. 6 68. 5 63. 1 86. 2
568 Circular of the National Bureau of Standards
TABLE 78.-Reducing-sugar values by the Munson and Walker method—Continued
Values of National Bureau of Standards (Hammond)
I t Invert Sugar and Sucrose
In WGºr
Copper Cºns DextroSe i. Levulose
** * * * *- : *-* 0.3 g of total 0.4 g of total 2.0 g of total
Sugar Sugar Sugar
Tng Tng ing 7mg Tng Tng Tng Tng
95 107. 0 46. 5 48. 8 47. 3 46. 8 40. 8 51. 1
96 108. 1 47. 0 49. 4 47. 8 47. 4 41. 3 51. 6
97 109. 2 47. 5 49. 9 48. 4 47. 9 41. 9 52. 2
98 110. 3 48. 0 50. 4 48. 9 48. 4 42. 4 52. 7
99 111. 5 48. 5 50. 9 49. 4 48. 9 42.9 53. 3
100 112. 6 49. 0 51. 5 50. 0 49. 5 43. 5 53. 8
101 113. 7 49. 5 52. 0 50. 5 50. 0 44. 0 54. 4
102 114. 8 50. 0 52. 5 51. 0 50. 5 44. 5 54. 9
103 116. 0 50. 6 53. 0 51. 6 51. 1 45. 1 55. 5
104 117. 1 51. 1 53. 6 52. 1 51. 6 45. 6 56. 0
105 118. 2 51. 6 54. 1 5.2. 6 52. 1 46. 1 56. 6
106 119. 3 52. 1 54. 6 53. 1 52. 7 46. 7 57. 1
107 120. 5 5.2. 6 55. 2 53. 7 53. 2 47. 2 57. 7
108 121. 6 53. 1 55. 7 54. 2 53. 7 47. W 58. 2
109 122. 7 53. 6 56. 2 54. 7 54. 2 48. 3 58. 8
110 123. 8 54. 1 56. 7 55. 3 54. 8 48. 8 59. 3
111 125. 0 54. 6 57. 3 55. 8 55. 3 49. 3 59. 9
112 126. I 55. 1 57. 8 56. 3 55. 8 49. 9 60. 4
113 127. 2 55. 6 58. 3 56. 9 56.4 50. 4 61. 0
1 14 128. 3 56. 1 58. 9 57. 4 56. 9 50. 9 61. 6
115 129. 5 56. 7 59. 4 57. 9 57. 4 51. 5 62. 1
I 16 130. 6 57. 2 59. 9 58. 5 58. 0 52. 0 62. 7
117 131. 7 57. 7 60. 4 59. 0 58. 5 52. 5 63. 2
118 132. 8 58. 2 61. 0 59. 5 59. 0 53. 1 63. 8
119 134. 0 58. 7 61. 5 60. 1 59. 6 53. 6 64. 3
120 135. 1 59. 2 62. 0 60. 6 60. 1 54. 1 64. 9
121 136. 2 59. 7 62. 6 61. 2 60. 7 54. 7 65. 4
122 137. 4 60. 2 63. 1 61. 7 61. 2 55. 2 66. 0
123 138. 5 60. 7 63. 6 62. 2 61. 7 55. 8 66. 5
124 139. 6 61. 3 64. 2 62. 8 62. 3 56. 3 67. 1
125 140. 7 61. 8 64. 7 63. 3 62. 8 56. 8 67. 7
126 141. 9 62. 3 65. 2 63. 8 63. 3 57. 4 68. 2
127 143. 0 62. 8 65. 8 64. 4 63. 9 57. 9 68. 8
128 144. 1 63. 3 66. 3 64. 9 64. 4 58.4 69. 3
129 145. 2 63. 8 66. 8 65. 4 64. 9 59. 0 69. 9
130 146. 4 64. 3 67. 4 66. 0 65. 5 59. 5 70. 4
131 147. 5 64. 9 67. 9 66. 5 66. 0 60. 1 71. 0
132 148. 6 65. 4 68. 4 67. 1 66. 6 60. 6 71.6
133 149. 7 65. 9 69. 0 67. 6 67. 1 61. 1 72. 1
134 150. 9 66. 4 69. 5 68. 1 67. 6 61. 7 72.7
135 152. 0 66. 9 70. 0 68. 7 68. 2 62. 2 73. 2
136 153. 1 67. 4 70. 6 69. 2 68. 7 62. 8 73. 8
137 154. 2 68. 0 71. 1 69. 8 69. 3 63. 3 74. 3
138 155. 4 68. 5 71.6 70. 3 69. 8 63. 9 74. 9
139 156. 5 69. 0 72. 2 70. 8 70. 3 64. 4 75. 5
See footnotes at end of table.
Polarimetry, Saccharimetry, and the Sugars
569
TABLE 78.—Reducing-sugar values by the Munson and Walker method—Continued
Values of Straughn and Given
Values of
Walker

Lactose.H2O and sucrose
Copper Cuprous oxide Lactose.H2O - Maltose.H2O
1 lactose 1 lactose
4. SucroSé 12 SuCrOSe
ng 7mg Tng 7mg Tng mg
95 107. 0 71.4 69. 3 63. 8 87. 2
96 108. 1 72. 2 70. 0 64. 4 88. 1
97 109. 2 72. 9 70. 8 65. 1 89. 0
98 110. 3 73. 7 71. 5 65. 8 90. 0
99 111. 5 74. 5 72. 3 66. 4 90. 9
100 112. 6 75. 2 73. 0 67. 1 91. 8
101 113. 7 76. 0 73. 8 67. 7 92. 8
102 114. 8 76. 8 74. 5 68. 4 93. 7
103 116. 0 77. 6 75.3 69. 1 94. 7
104 117. 1 78. 4 76. 1 69. 7 95. 6
105 118. 2 79. 1 76. 8 70. 4 96. 6
106 119. 3 79. 8 77. 5 71. 1 97. 5
107 120. 5 80. 6 78. 3 71. 8 98. 4
108 121. 6 81.4 79. 1 72. 5 99. 4
109 122. 7 82. 2 79. 8 73. 1 100. 3
110 123. 8 83. 0 80. 6 73. 8 101. 3
111 125. 0 83. 8 81. 3 74. 5 102. 2
112 126. 1 84. 5 82. 1 75. 2 103. 1
113 127. 2 85. 3 82. 8 75. 8 104. 1
114 128. 3 86. 1 83. 6 76. 5 105. 0
115 129. 5 86. 8 84. 3 77. 2 106. 0
116 130. 6 87. 6 85. 1 77. 9 106. 9
117 131. 7 88.4 85. 9 78. 5 107. 8
118 132. 8 89. 2 86. 6 79.2 108. 8
119 134. 0 90. 0 87. 4 79. 9 109. 7
120 135. 1 90. 7 88. 1 80. 6 110. 6
121 136. 2 91. 5 88. 9 81. 2 111. 6
122 137. 4 92. 3 89. 6 81. 9 112. 5
123 138. 5 93. 0 90. 4 82. 6 113. 5
124 139. 6 93. 8 91. 2 83. 3 114. 4
125 140. 7 94. 6 91. 9 84. 0 115. 3
126 141. 9 95.4 92. 7 84. 6 116. 3
127 143. 0 96. 1 93.4 85. 3 117. 2
128 144. 1 96. 9 94. 2 86. 0 118. 1
129 145. 2 97. 7 94. 9 86. 7 119. 1
130 146.4 98. 5 95. 7 87. 3 120. 0
131 147. 5 99. 2 96. 4 88. 0 120. 9
132 148. 6 100. 0 97.2 88, 7 121. 9
133 149, 7 100. 8 98. 0 89.4 122. 8
134 150. 9 101. 5 98. 8 90. 1 123. 8
135 152. 0 102. 3 99. 5 90. 8 124. 7
136 153. 1 103. 1 100. 2 91. 5 125. 6
137 154. 2 103.9 101. 0 92. 1 126. 6
138 155.4 104. 7 101. 7 92. 8 127. 5
139 156. 5 105.4 102. 5 93. 5 128. 4
570 Circular of the National Bureau of Standards
TABLE 78.-Reducing-sugar values by the Munson and Walker method—Continued
Values of National Bureau of Standards (Hammond)
I t Invert Sugar and Sucrose
Il Ver
Copper Cºns DextroSe j Levulose
4. 0.3 g of total 0.4 g of total 2.0 g of total
Sugar Sugar Sugar
7mg 7/7 7ng 7ng Tng Tng Tng 7mg
140 157. 6 69. 5 72. 7 71.4 70. 9 64. 9 76. 0
141 158, 7 70. 0 73. 2 71. 9 71. 4 65. 5 76. 6
142 159. 9 70. 5 73. 8 72. 5 72. 0 66. 0 77. 1
143 161. 0 71. 1 74. 3 73. 0 72. 5 66. 6 77.7
144 162. 1 71.6 74. 9 73. 5 73. 0 67. 1 78. 3
145 163. 2 72. 1 75. 4 74. 1 73. 6 67. 7 78. 8
146 164. 4 7.2. 6 75. 9 74, 6 74. 1 68. 2 79. 4
147 165. 5 73. 1 76. 5 75. 2 74. 7 68. 7 80. 0
148 166. 6 73. 7 77. 0 75. 7 75. 2 69. 3 80. 5
149 167. 8 74. 2 77. 6 76. 3 75. 7 69. 8 81. 1
150 168. 9 74. 7 78. 1 76. 8 76. 3 70. 4 81. 6
151 170. 0 75. 2 78. 6 77. 3 76. 8 70. 9 82. 2
152 171. 1 75. 7 79. 2 77. 9 77. 4 71, 5 82. 8
153 172. 3 76. 3 79. 7 78. 4 77. 9 72. 0 83. 3
154 173. 4 76. 8 80. 3 79. 0 78. 5 7.2. 6 83. 9
155 174. 5 77.3 80. 8 79. 5 79. 0 73. I 84.4
156 175. 6 77.8 81. 3 80. 1 79. 6 73. 7 85. 0
157 176. 8 78. 3 81. 9 80. 6 80. 1 74. 2 85. 6
158 177. 9 78. 9 82. 4 81. 2 80. 6 74. 8 86. 1
1.59 179. 0 79. 4 83. 0 81. 7 81. 2 75. 3 86. 7
160 180. 1 79. 9 83. 5 82. 2 81. 7 75. 9 87. 3
161 181. 3 80. 4 84. 0 82. 8 82. 3 76. 4 87. 8
162 182. 4 81. 0 84. 6 83. 3 82. 8 77. 0 88. 4
163 183. 5 81. 5 85. 1 83. 9 83. 4 77. 5 89. 0
164 184. 6 82. 0 85. 7 84. 4 83. 9 78. 1 89. 5
165 185. 8 82. 5 86. 2 85. 0 84. 5 78. 6 90. 1
166 186. 9 83. 1 86. 8 85. 5 85. 0 79.2 90. 6
167 188. 0 83. 6 87. 3 86. 1 85. 6 79. 7 91. 2
168 189. 1 84. 1 87. 8 86. 6 86. 1 80. 3 91. 8
169 190. 3 84. 6 88. 4 87. 2 86. 7 80. 8 92. 3
170 191. 4 85. 2 88. 9 87.7 87. 2 81. 4 92. 9
171 192. 5 85. 7 89. 5 88. 3 87. 8 81. 9 93. 5
172 193. 6 86. 2 90. 0 88. 8 88. 3 82. 5 94. 0
173 194. 8 86. 7 90. 6 89. 4 88. 9 83. 0 94. 6
174 195. 9 87. 3 91. 1 89. 9 89. 4 83. 6 95. 2
175 197. 0 87. 8 91. 7 90. 5 90. 0 84. 1 95. 7
176 198. I 88. 3 92. 2 91. 0 90. 5 84. 7 96.3
177 199. 3 88. 9 92. 8 91. 6 91. 1 85. 2 96.9
178 200. 4 89. 4 93. 3 92. 1 91. 6 85. 8 97. 4
179 201. 5 89. 9 93. 8 92. 7 92. 2 86. 3 98. 0
180 202. 7 90. 4 94.4 93. 2 92. 7 86. 9 98. 6
181 203. 8 91. 0 94. 9 93. 8 93. 3 87. 4 99. 2
182 204. 9 91. 5 95. 5 94. 3 93. 8 88. 0 99. 7
183 206. 0 92. 0 96. 0 94. 9 94. 4 88. 6 100.3
184 207. 2 92. 6 96. 6 95.4 94. 9 89. 1 100. 9
See footnotes at end of table.
Polarimetry, Saccharimetry, and the Sugars
571
TABLE 78.-Reducing-sugar values by the Munson and Walker method—Continued
Values of Straughn and Given
ii
-
:
ii
Copper Cuprous oxide' Lactose.H2O
Tilg Tng Tng
140 157. 6 106.
141 158. 7 107.
142 159, 9 107.
143 161. 0 108.
144 162. 1 109.
145 163. 2 110.
146 164. 4 110
147 165. 5 111
148 166. 6 112
149 167. 8 113.
150 168. 9 114.
151 170. 0 114
152 171. 1 115
153 172. 3 116
154 173. 4 117.
155 174. 5 117.
156 175. 6 118
157 176. 8 119
158 177. 9 120
1.59 179. 0 121.
160 180. 1 121.
161 181. 3 122.
162 182. 4 123.
163 183. 5 124.
164 184. 6 124.
165 185. 8 125.
166 186. 9 126.
167 188. 0 127.
168 189. 1 128.
169 190. 3 128.
170 191. 4 129.
171 192. 5 130.
172 193. 6 131.
173 194. 8 131.
174 195. 9 132.
175 197. 0 133.
176 198. 1 134.
177 199. 3 134.
178 200. 4 135.
179 201. 5 136.
180 202. 7 137.
181 203. 8 138.
182 204. 9 138.
183 206. 0 139.
184 207, 2 140.
i
Values of
Walker
Lactose.H2O and Sucrose
Malt;OSe.H2O
1 lactose 1 lactose
4 SucroSe 12 SucroSe
mg Tng 7mg
103. 2 94. 2 129. 4
104. 0 94. 8 130. 3
104. 8 95. 5 131. 3
105. 5 96. 2 132. 2
106. 3 96. 9 133. 1
107. 0 97. 6 134. 1
107. 8 98. 2 135. 0
108. 5 98.9 135. 9
109. 3 99. 6 136. 9
110. 0 100. 3 137. 8
110. 8 100. 9 138. 8
111. 6 101. 6 139. 7
112. 3 102. 3 140. 6
113. 1 103. 0 141. 6
113. 8 103. 7 142. 5
114. 6 104.4 143. 4
115. 3 105. 1 144. 4
116. 1 105. 8 145. 3
116. 9 106. 4 146. 3
117. 6 107. 1 147. 2
118. 4 107. 8 148. 1
119. 2 108. 5 149. 1
119. 9 109. 1 150. 0
120. 7 109. 8 150. 9
121. 5 110. 5 151. 9
122. 2 111. 1 152. 8
123. 0 111. 8 153. 8
123. 7 112. 5 154. 7
124. 5 113. 2 155. 6
125. 3 113. 9 156. 6
126. 0 114. 6 157. 5
126. 8 115. 3 158. 4
127. 5 116. 0 159. 4
128. 3 116. 7 160. 3
129. 1 117. 3 161. 3
129. 8 118. 0 162. 2
130. 6 118. 7 163. 1
131. 4 119. 4 164. 1
132. 1 120. 1 165. 0
132. 9 120. 7 166. 0
133. 7 121.4 166. 9
134. 4 122. 1 167. 8
135. 2 122.8 168. 8
135. 9 123. 5 169. 7
136. 7 124. 2 170. 6
572
Circular of the National Bureau of Standards
TABLE 78.-Reducing-sugar values by the Munson and Walker method—Continued
Values of National Bureau of Standards (Hammond)
Cuprous
Invert
Invert Sugar and Sucrose
Copper oxide Dextrose Sugar Levulose
0.3 g of total 0.4 g of totall 2.0 g of total
Sugar Sugar Sugar
mg Tng Tng mg mg Tng Tng Tng
185 208. 3 93. I 97. 1 96. 0 95. 5 89. 7 101. 4
186 209. 4 93. 6 97. 7 96. 5 96. 0 90. 2 102. 0
187 210. 5 94. 2 98. 2 97. 1 96. 6 90. 8 102. 6
188 211. 7 94. 7 98. 8 97. 6 97. 1 91. 3 103. 1
189 212. 8 95. 2 99. 3 98. 2 97. 7 91, 9 103. 7
190 213. 9 95. 7 99.9 98. 7 98. 2 92. 4 104. 3
191 215. 0 96.3 100. 4 99. 3 98. 8 93. 0 104. 8
192 216. 2 96. 8 101. O 99.9 99. 4 93. 6 105. 4
193 217. 3 97. 3 101. 5 100. 4 99. 9 94. I 106. ()
194 218. 4 97. 9 102. 1 101. 0 100. 5 94. 7 106. 6
195 219. 5 98. 4 102. 6 101. 5 101. 0 95. 2 107. 1
196 220. 7 98. 9 103. 2 102. I 101. 6 95. 8 107. 7
197 221. 8 99. 5 103. 7 102. 6 102. 1 96.4 108. 3
198 222. 9 100. () 104. 3 103. 2 102. 7 96.9 108. 8
199 224. 0 100. 5 104. 8 103. 7 103. 2 97. 5 109. 4
200 225. 2 101. 1 105. 4 104. 3 103. 8 98. 0 110. 0
201 226. 3 101. 6 106. 0 104. 9 104.4 98. 6 110. 6
202 227. 4 102. 2 106. 5 105. 4 104. 9 99. 2 111. 1
203 228. 5 102. 7 107. 1 106. 0 105. 5 99. 7 111. 7
204 229. 7 103. 2 107. 6 106. 5 106. 0 100, 3 112. 3
205 230. 8 103. 8 108. 2 107. 1 106. 6 100. 9 112. 9
206 231. 9 104. 3 || 108, 7 107. 6 107. 2 101. 4 113. 4
207 233. 1 104. 8 109. 3 108. 2 107. 7 102. 0 114. 0
208 234. 2 105. 4 109. 8 108. 8 108. 3 102. 5 114. 6
209 235. 3 105. 9 110. 4 109. 3 108. 8 103. 1 115. 2
210 236. 4 106. 5 110. 9 109. 9 109. 4 103. 7 115. 7
211 237. 6 107. 0 111. 5 110. 4 110. 0 104. 2 116. 3
212 238, 7 107. 5 112. 1 111. 0 110. 5 104. 8 116. 9
213 239. 8 108. 1 112. 6 111. 6 111. 1 105. 4 117. 5
214 240. 9 108. 6 113. 2 112. 1 111. 6 105. 9 118. 0
215 242. 1 109. 2 113. 7 112. 7 112. 2 106. 5 118. 6
216 243. 2 109. 7 114. 3 113. 2 112. 8 107. 1 119. 2
217 244. 3 110. 2 114. 9 113. 8 113. 3 107. 6 119. 8
218 245. 4 110. 8 115. 4 114. 4 113. 9 108. 2 120. 3
219 246. 6 111. 3 116. 0 114. 9 114. 4 108. 8 120. 9
220 247. 7 111. 9 116. 5 115. 5 115. 0 109. 3 121. 5
221 248. 8 112. 4 117. 1 116. 1 115. 6 109. 9 122. 1
222 249. 9 112. 9 117. 6 116. 6 116. 1 110. 5 122. 6
223 251. 1 113. 5 118. 2 117. 2 116. 7 111. 0 123. 2
224 252. 2 114. 0 118. 8 117. 7 117. 3 111. 6 123. 8
225 253. 3 114. 6 119. 3 118. 3 117. 8 112. 2 124. 4
226 254. 4 115. 1 119. 9 118. 9 118. 4 112. 7 125. 0
227 255. 6 115. 7 120. 4 119. 4 119. 0 113. 3 125. 5
228 256. 7 116. 2 121. 0 120. 0 119. 5 113. 9 126. 1
229 257. 8 116. 7 121. 6 120. 6 120. 1 114. 4 126. 7
See footnotes at end of table.
Polarimetry, Saccharimetry, and the Sugars
573
TABLE 78.-Reducing-sugar values by the Munson and Walker method—Continued
Values of Straughn and Given
Values of
Walker
Lactose.H2O and SucroSe
Copper Cuprous oxide Lactose.H2O Maltose.H2O
1 lactose 1 lactose
4 SucroSe 12 SucroSe
7mg 7mg Tng Tng 7mg Tng
185 208. 3 141. 2 137. 5 124. 9 171. 6
186 209. 4 141. 9 138. 2 125. 6 172. 5
187 210. 5 142. 7 139. 0 126. 3 173.4
188 211. 7 143. 5 139, 8 127. 0 174. 4
189 212. 8 144. 3 140. 6 127. 7 175. 3
190 213. 9 145. 0 141. 3 128. 3 176. 3
191 215. 0 145. 8 142. 1 129. 0 177.2
192 216. 2 146. 6 142. 8 129. 7 178. 1
193 217. 3 147. 4 143. 6 130.4 179. 1
194 218. 4 148. 2 144. 3 131. 1 180. 0
195 219. 5 149. 0 145. 1 131. 8 180. 9
196 220. 7 149. 8 145. 9 132. 5 181. 9
197 221. 8 150. 5 146. 6 133. 2 182. 8
198 222. 9 151. 3 147.4 133. 9 183. 8
199 224. 0 152. 0 148. 1 134. 6 184. 7
200 225. 2 152. 8 148. 9 135. 3 185. 6
201 226. 3 153. 6 149. 7 136. 0 186. 6
202 227. 4 154. 4 150. 5 136. 6 187. 5
203 228. 5 155. 2 151. 2 137. 3 188. 5
204 229. 7 156. 0 152. 0 138. 0 189. 4
205 230. 8 156. 8 152. 8 138. 7 190. 4
206 231. 9 157. 5 153. 5 139. 4 191. 3
207 233. 1 158. 3 154. 3 140. 1 192. 2
208 234. 2 159. 1 155. 0 140. 8 193. 1
209 235. 3 159. 8 155. 8 141. 5 194. 1
210 236. 4 160. 6 156. 5 142. 2 195. 0
211 237. 6 161. 4 157. 3 142. 9 195. 9
212 238, 7 162. 2 158. 1 143. 6 196. 9
213 239, 8 163. 0 158. 8 144. 3 197. 8
214 240. 9 163. 8 159. 6 145. 0 198. 8
215 242. 1 164. 5 160. 4 145. 7 199. 7
216 243. 2 165. 3 161. 1 146. 4 200. 6
217 244. 3 166. 1 161. 9 147. 1 201. 6
218 245. 4 166. 9 162. 7 147. 8 202. 5
219 246. 6 167. 7 163. 4 148. 4 203. 5
220 247. 7 168. 5 164. 2 149. 1 204. 4
221 248. 8 169. 3 165. 0 149. 8 205. 3
222 249. 9 170. 0 165. 7 150. 5 206. 3
223 251. 1 170. 8 166. 5 151. 2 207. 2
224 252. 2 171. 6 167. 3 151. 9 208. 1
225 253. 3 172. 3 168. 0 152. 6 209. 1
226 254. 4 173. 1 168. 8 153. 3 210. 0
227 255. 6 173. 9 169. 6 154. 0 211. 0
228 256. 7 174. 7 170. 4 154. 7 211. 9
229 257. 8 175. 5 171. 2 155. 4 212. 8
323414 °—42
38
574
Circular of the National Bureau of Standards
TABLE 78. –Reducing-sugar values by the Munson and Walker method—Continued
Values of National Bureau of Standards (Hammond)
Invert Sugar and sucrose
C sº Invert
Copper º l) extrose § . – |
0.3 g of total 0.4 g of total 2.0 g of total
Sugar Sugar Sugar
Tng | ing | 7ng mg 7ng } Tng Tng
330 258, 9 1íž. 3 13%. 1 131. 1 120.7 ſis. 0
231 260. 1 117.8 122, 7 121. 7 121. 2 115. 6
232 261. 2 | | 18.4 123. 3 122. 3 121.8 116. 2
233 262. 3 18, 9 123. 8 122.8 122.4 116. 7
234 263.4 119, 5 124. 4 123. 4 122, 9 117 3
235 264, 6 120 0 124, 9 124. 0 123, 5 117. 9
236 265. 7 120, 6 125, 5 124, 5 124 i 118. A
237 266. 8 121. 1 126. 1 125. 1 124. 6 119. 0
238 268. Q 121 : 26, 6 || ||25 || 125. 2 119. 6
239 269. 1 | 122, 2 127. 2 126, 2 125. 8 120. 2
240 270. 2 | 122. 7 | 127, 8 126. 8 126, 3 | 120. 7
241 271. 3 123. 3 | 128. 3 127. 4 126. 9 121. 3
242 272, 5 123. 8 || 128. 9 127. 9 127. 5 121. 9
243 273. 6 124. 4 || 129. 5 128. 5 128. 0 122. 5
244 274, 7 || 124. 9 || 130. 0 129. I 128. 6 123. 0
245 275. 8 125. 5 || 130. 6 129. 6 129. 2 123. 6
246 277. 0 | 126. 0 || 131. 2 130, 2 129. 8 124. 2
247 278. 1 | 126. 6 || 131. 7 130. 8 130. 3 #:
248 279. 2 | 127. 1 || || 32. 3 131. 3 130. 9 125.
249 280. 3 || 127. 7 || 132. 9 13]. 9 131. 5 125. 9
250 281. 5 || 128. 2 | 133. 4 132. 5 132. 0 126. 5
251 282. 6 128. 8 || 134. 0 133. 1 132. 6 127. 1
252 283. 7 || 129. 3 || 134. 6 133. 6 133. 2 127. 6
253 284. 8 || 129. 9 135. 1 134. 2 133. 8 128. 2
254 286. 0 || 130. 4 || 135. 7 134. S 134. 3 128. 8
255 287. 1 131. 0 || 136. 3 135. 3 134. 9 129. 4
256 288. 2 || 131. 6 || 136. 8 135. 9 135. 5 130. 0
257 289. 3 || 132. 1 || 137. 4 136. 5 136. 0 130. 5
258 290. 5 || 132. 7 || 138. 0 137. 1 136. 6 131. 1
259 291. 6 133. 2 | 138 – 6 137. 6 137. 2 131. 7
260 292. 7 || 133. 8 || 139. 1 138. 2 137. 8 132. 3
261 293. 8 || 134. 3 || 139. 7 138. 8 138. 3 132. 9
262 295. 0 || 134. 9 || 140. 3 139. 4 138. 9 133. 4
263 296. 1 || 1 35. 4 || 140. 8 139. 9 139. 5 #:
264 297. 2 136. 0 || 141. 4 140. 5 140. 1 134.
265 298. 3 || 136. 5 | 1.42. 0 141. 1 140. 7 135. 2
266 299. 5 || 137. 1 || 142. 6 141. 7 141. 2 135. 8
267 300. 6 || 137. 7 | 1.43. 1 142. 2 14.1. 8 136. 3
268 301. 7 || 138. 2 | 1.43. 7 142, 8 142. 4 136. 9
269 302. 9 || 138. 8 || 144. 3 143. 4 143. 0 137. 5
270 304. 0 || 139. 3 144. 8 144. 0 143. 5 138. 1
271 305. 1 139. 9 || 145. 4 144. 5 144. 1 138. 7
272 306. 2 | 1.40. 4 146. 0 145. 1 144. 7 139. 3
273 307. 4 || 141. 0 || 146. 6 145. 7 145. 3 139. 8
274 308. 5 | 1.41. 6 | 1.47. 1 146. 3 145. 9 140. 4
Seo footnotes at end of table.
Levulose
I
2
eº8.g
i
li
43
gÖ.reeºº*g&ſºſºe*gtºi.g
1
4
i
i
Polarimetry, Saccharimetry, and the Sugars
575
TABLE 78.—Reducing-sugar values by the Munson and Walker method—Continued
Values of Straughn and Given
Values of
Walker
Lactose.H2O and sucrose
Copper Cuprous oxide Lactose.H2O Maltose.H2O
1 lactose 1 lactose
4 SuCrOSé 12 SuCrOSe
Tng ng mg mg Tng 7mg
230 258. 9 176. 3 171. 9 156. 1 213. 8
231 260. I 177. 1 172. 6 156. 8 214. 7
232 261. 2 177. 8 173. 4 157. 5 215. 6
233 262. 3 178. 6 174. 2 158. 2 216. 6
234 263. 4 179. 4 175. 0 158. 9 217. 5
235 264. 6 180. 2 175. 7 159. 6 218. 5
236 265. 7 181. 0 176. 5 160. 3 219. 4
237 266. 8 18.1. 8 177. 3 161. 0 220. 3
238 268. 0 182. 6 178. 0 161. 7 221. 3
239 269. 1 183. 3 178. 8 162. 4 222. 2
240 270. 2 184. 1 179. 6 163. 1 223. 1
241 271. 3 184. 8 180. 3 163. 8 224. 1
242 272. 5 185. 6 181. 1 164. 5 225. 0
243 273. 6 186. 4 181. 9 165. 2 226. 0
244 274. 7 187. 2 182. 6 165. 9 226. 9
245 275. 8 188. 0 183. 4 166. 7 227. 8
246 277. 0 188. 8 184. 2 167. 4 228. 8
247 278. 1 189. 6 184. 9 168. 1 229. 7
248 279. 2 190. 4 185. 7 168. 8 230. 7
249 280. 3 191. 1 186. 5 169. 5 231. 6
250 281. 5 191. 9 187. 3 170. 2 232. 5
251 282. 6 192. 7 188. 0 170. 9 233. 5
252 283. 7 193. 5 188. 8 171. 6 234. 4
253 284. 8 194. 3 189. 6 172. 3 235. 3
254 286. 0 195. 1 190. 3 173. 0 236. 3
255 287. 1 195. 8 191. I 173. 7 237. 2
256 288. 2 196. 6 191. 9 174. 4 238. 2
257 289. 3 197. 4 192. 6 175. 1 239. 1
258 290. 5 198. 1 193. 4 175. 8 240. 0
259 291. 6 198. 9 194. 2 176. 5 | 240. 9
260 292. 7 199. 7 194. 9 177. 2 241. 9
261 293. 8 200. 5 195. 7 178. 0 242. 8
262 295. 0 201. 3 196. 5 178. 7 243. 7
263 296. 1 202. 1 197. 2 179. 4 244. 7
264 297. 2 202. 9 198. 0 180. 1 245. 6
265 298. 3 203. 7 198. 8 180. 8 246. 6
266 299. 5 204. 4 199. 5 181. 5 247. 5
267 300. 6 205. 2 200. 3 182. 2 248. 4
268 301. 7 206. 0 201. 1 182. 9 249. 4
269 302. 9 206. 8 201. 9 183. 6 250. 3
270 304. 0 207. 6 202. 7 184. 4 251. 2
271 305. 1 208. 4 203. 4 185. 1 252. 2
272 306. 2 209. 2 204. 2 185. 8 253. 1
273 307. 4 209. 9 204. 9 186. 5 254. 1
274 308. 5 210. 7 205. 7 187. 2 255. 0
576
Circular of the National Bureau of Standards
TABLE 78.-Reducing-sugar values by the Munson and Walker method—Continued
Values of National Bureau of Standards (Hammond)
Cuprous
Invert
Invert Sugar and Sucrose
Copper oxide Dextrose Sugar Levulose
0.3 g of total 0.4 g of total 2.0 g of total
Sugar Sugar Sugar
Tng Tng 7mg Tng Tng Tng Tmg Tng
275 309. 6 142. 1 147, 7 146. 8 146.4 141. 0 153. 6
276 310. 7 142. 7 148. 3 147. 4 147. 0 141. 6 154. 2
277 311. 9 143. 2 148. 9 148. 0 147. 6 142. 2 154. 8
278 313. 0 143. 8 149. 4 148. 6 148. 2 142. 8 155. 4
279 314. 1 144, 4 150, 0 149. 2 148. 8 143. 4 156. ()
280 315. 2 144. 9 150. 6 149. 7 149. 3 143. 9 156. 5
281 316. 4 145. 5 151. 2 150. 3 149. 9 144. 5 157. 1
282 317. 5 146. 0 151. 8 150. 9 150. 5 145. 1 157. 7
283 3.18. 6 146. 6 152. 3 151. 5 151. 1 145. 7 158. 3
284 3.19. 7 147. 2 152, 9 152. 1 151. 7 146. 3 158. 9
285 320. 9 147. 7 153. 5 152. 6 152. 2 146. 9 159. 5
286 322. 0 148. 3 154. 1 153. 2 152. 8 147. 5 160. 1
287 323. 1 148. 8 154, 6 153. 8 153. 4 148. 1 160, 7
288 324. 2 149. 4 155. 2 154.4 154. 0 148. 6 161. 3
289 325. 4 150. 0 | 155.8 155. 0 154. 6 149. 2 161. 9
290 326. 5 150. 5 156. 4 155. 5 155. 2 149. 8 162. 5
291 327. 6 151. 1 157. 0 156. 1 155.7 150. 4 163. 1
292 328. 7 151. 7 157. 5 156. 7 156. 3 151. 0 163. 7
293 329. 9 152. 2 158. 1 157. 3 156. 9 151. 6 164. 3
294 331. 0 152. 8 158, 7 157. 9 157. 5 152. 2 164. 9
295 332. 1 153. 4 159. 3 158. 5 158. 1 152. 8 165. 4
296 333. 3 153. 9 159. 9 159. 0 158. 7 153. 4 166. 0
297 334. 4 154. 5 160. 5 159. 6 159. 3 154. 0 166. 6
298 335. 5 155. 1 161. 0 160. 2 159. 9 154. 6 167. 2
299 336. 6 155. 6 161. 6 160, 8 160. 4 155. 2 167. 8
300 337. 8 156. 2 162. 2 161. 4 161. 0 155. 7 168. 4
301 338. 9 156. 8 162. 8 162. () 161. 6 156. 3 169. 0
302 340. 0 157. 3 163. 4 162. 5 162. 2 156. 9 169. 6
303 341. 1 157. 9 164. 0 163. 1 162. 8 157. 5 170. 2
304 342. 3 158. 5 164. 5 163. 7 163. 4 158. 1 170. 8
305 343. 4 159. 0 165. 1 164. 3 164. 0 158. 7 171. 4
306 344. 5 159. 6 165. 7 164, 9 164, 6 159. 3 172. 0
307 345. 6 160. 2 166. 3 165. 5 165. 1 159. 9 172. 6
308 346. 8 160. 7 166. 9 166. 1 165. 7 160. 5 173. 2
309 347. 9 161. 3 167. 5 166. 7 166. 3 16.1. 1 173. 8
310 349. 0 161. 9 168. 0 167. 2 166, 9 161. 7 174. 4
311 350. 1 162. 5 168. 6 167. 8 167. 5 162. 3 175. 0
312 351. 3 163. 0 169. 2 168.4 168. 1 162. 9 175. 6
313 352. 4 163. 6 169. 8 169. 0 168. 7 163. 5 176. 2
314 353. 5 164. 2 170. 4 169. 6 169. 3 164. 1 176. 8
315 354. 6 164. 7 171. 0 170. 2 169, 9 164. 7 177. 4
316 355. 8 165. 3 171. 6 170. 8 170. 5 165. 3 178. 0
317 356. 9 165. 9 172. 2 171. 4 171. 1 165. 9 178. 6
318 358. 0 166. 5 172. 8 172. 0 171. 7 166. 5 179. 2
319 359. 1 167. 0 173. 3 17.2. 6 172. 2 167. 1 179. 8
Polarimetry, Saccharimetry, and the Sugars
577
TABLE 78.—Reducing-sugar values by the Munson and Walker method–Continued

Values of Straughn and Given Yº...!
Lactose.H2O and sucrose
Copper Cuprous oxide Lactose.H2O Maltose.H2O
1 lactose 1 lactose
4 SucroSe 12 SuCrOSe
7Ilg. Tng Tng Tng Tng Tng
275 309. 6 211. 5 206. 5 187. 9 255.9
276 310. 7 212. 3 207. 3 188. 6 256. 9
277 3.11. 9 213. 1 208. 1 189. 3 257. 8
278 313. 0 213. 9 208. 8 190. 0 258. 8
279 314. 1 214. 7 209. 6 190. 7 259. 7
280 315. 2 215. 5 210. 4 191. 4 260. 6
281 316. 4 216. 2 211. 1 192. 1 261. 5
282 317. 5 217. 0 211. 9 192. 9 262. 5
283 318. 6 217. 7 212. 7 193. 6 263. 4
284 319. 7 218. 5 213. 4 194. 3 264. 4
285 320. 9 219. 3 214, 2 195. 0 265. 3
286 322. 0 220. 1 215. 0 195. 7 266. 2
287 323. 1 220. 9 215. 8 196. 4 267. 2
288 324. 2 221. 7 216. 5 197. 1 268. 1
289 325. 4 222. 5 217. 3 197. 8 269. 0
290 326. 5 223. 3 218. 1 198. 6 270. 0
291 327. 6 224. 0 218. 8 199. 3 270. 9
292 328. 7 224. 8 219. 6 200. 0 271. 9
293 329. 9 225. 6 220. 4 200. 7 272.8
294 331. 0 226. 4 221. 2 201. 4 273. 7
295 332. 1 227. 2 221. 9 202. 1 274. 7
296 333. 3 228. 0 222. 7 202. 8 275. 6
297 334. 4 228. 8 223. 5 203. 6 276. 5
298 335. 5 229. 6 224. 3 204. 3 277. 5
299 336. 6 230. 3 225. 0 205. 0 278. 4
300 337. 8 231. 1 225. 8 205. 7 279. 3
301 338. 9 231. 9 226. 6 206. 4 280. 3
302 340. 0 232. 7 227. 4 207. 1 281. 2
303 341. 1 233. 5 228, 2 207. 8 282. 1
304 342. 3 234. 3 228, 9 208. 5 283. 1
305 343. 4 235. 1 229. 7 209. 3 284. 0
306 344. 5 235. 9 230. 5 210. 0 284. 9
307 345. 6 236. 6 231. 2 210. 7 285. 9
308 346. 8 237. 4 232. 0 211. 5 286. 8
309 347. 9 238. 2 232. 8 212. 2 287. 8
310 349. 0 239. 0 233. 6 212. 9 288. 7
311 350. 1 239, 8 234. 4 213. 6 289. 6
312 351. 3 240. 6 235. 1 214. 3 290. 6
313 352. 4 241. 4 235. 9 215. 0 291. 5
314 353. 5 242. 2 236. 7 215. 7 292. 4
315 354. 6 242. 9 237. 4 216. 5 293. 4
316 355. 8 243. 7 238. 2 217, 2 294, 3
317 356. 9 244. 5 239. 0 217. 9 295. 2
3.18 358. 0 245. 3 239. 8 218. 6 296. 2
319 359. 1 246. 1 240. 6 219. 3 297. 1
See footnotes at end of table.
578
Circular of the National Bureau of Standards
TABLE 78.-Reducing-sugar values by the Munson and Walker method–Continued
Values of National Bureau of Standards (Hammond)
I t Invert Sugar and Sucrose
Copper Clºs Dextrose j Levulose
- - 0.3 g of total 0.4 g of total 2.0 g of total
Sugar Sugar Sugar
'IIlg. TIlg. ing Illg TIlg Tng ing Illg
320 360. 3 167. 6 173. 9 173. 1 172. 8 167. 7 180. 4
321 361. 4 168. 2 174: 5 173. 7 173. 4 168. 3 181, 0
322 362. 5 168. 8 175. 1 174. 3 174. () 168. 9 181, 6
323 363. 6 169. 3 175. 7 174. 9 174, 6 169. 5 182, 2
324 364, 8 169. 9 176. 3 175. 5 175. 2 170. 1 182, 8
325 365. 9 170. 5 176. 9 176. 1 175. 8 170. 7 183. 4
326 367. 0 17 l. 1 177. 5 176. 7 176. 4 171. 3 184. 0
327 368. 2 171. 6 178. 1 177. 3 177. 0 171, 9 184. 6
328 369. 3 172. 2 178. 7 177. 9 177. 6 172. 5 185, 2
329 370. 4 172. 8 179. 2 178. 5 178. 2 173. 1 185, 8
330 371. 5 173. 4 179. 8 179. I 178. 8 173. 7 186. 4
331 372. 7 173. 9 180. 4 179. 7 179. 4 174, 3 187. ()
332 373. 8 174. 5 181. 0 | 80. 3 180. () | 74. 9 187, 6
333 374. 9 175. 1 181. 6 180. 9 180. 6 175. 5 188, 2
334 376. () 175. 7 182. 2 181. 5 18 1. 2 176. 1 188. 8
335 377. 2 176. 3 182. 8 182. I 18.1. 8 | 76. 7 189, 4
336 378. 3 176. 8 183. 4 182. 6 182. 4 177. 3 190. 1
337 379. 4 177. 4 184. 0 183. 2 183. 0 178. () 190. 7
338 380. 5 178. 0 184. 6 183. 8 183. 6 178. 6 191. 3
339 381. 7 178. 6 185. 2 184.4 184. 2 179. 2 191, 9
340 382. 8 179. 2 185. 8 185. 0 184. 8 179. 8 192. 5
341 383. 9 179. 7 186. 4 185. 6 185: 4 180. 4 193, 1
342 385. 0 180. 3 187. 0 186. 2 186. 0 181. 0 193. 7
343 386. 2 180. 9 187. 6 186. 8 186. 6 181. 6 194. 3
344 387. 3 181. 5 188. 2 187. 4 187. 2 182. 2 194. 9
345 388. 4 182. 1 188. 8 188. 0 187. 8 182. 8 195, 5
346 389. 5 182. 7 189. 4 188. 6 188. 4 183. 4 196. 1
347 390. 7 183. 2 190. 0 189. 2 189. 0 184. 0 196, 7
348 391. 8 183. 8 190. 6 189. 8 189. 6 184. 6 197. 3
349 392. 9 184. 4 191. 2 190. 4 190. 2 185. 3 197. 9
350 394. 0 185. 0 191. 8 191. 0 190. 8 185. 9 198, 5
351 395. 2 185. 6 192. 4 191. 6 191. 4 186. 5 199. 2
352 396. 3 186. 2 193. 0 192. 2 192. 0 187. 1 199, 8
353 397. 4 186. 8 193. 6 192. 8 192. 6 187. 7 200, 4
354 398. 5 187. 3 194. 2 193. 4 193. 2 188. 3 201. 0
355 399. 7 187. 9 194. 8 194. 0 193. 8 188. 9 201, 6
356 400. 8 188. 5 195. 4 194. 6 194. 4 189. 5 202. 2
357 401. 9 189. 1 196. 0 195. 2 195. 0 190. 2 202, 8
358 403. 1 189. 7 196. 6 195. 8 195. 7 190. 8 203. 4
359 404. 2 190. 3 197. 2 196. 4 196. 3 191. 4 204. 0
360 405. 3 190. 9 197. 8 197. 1 196. 9 192. 0 204, 7
361 406. 4 191. 5 198. 4 197. 7 197. 5 192. 6 205. 3
362 407. 6 192. 0 199. 0 198. 3 198. 1 193. 2 205. 9
363 408. 7 192. 6 199. 6 198. 9 198. 7 193. 9 206. 5
364 409. 8 193. 2 200. 2 199. 5 199. 3 194. 5 207, 1
Polarimetry, Saccharimetry, and the Sugars
579
TABLE 78.-Reducing-sugar values by the Munson and Walker method–Continued
Values of Straughn and Given
Values of
Walker
Lactose.H2O and Sucrose
Copper Cuprous oxide Lactose.H2O Maitose. H2O
1 lactOSe l lactose
4 SucroSè 12 SucroSé
Ing Tilg Ing IIlg TIlg. Tng
320 360. 3 246. 9 241. 4 220. 1 298. 0
321 361. 4 247. 7 242. 1 220. 8 299. 0
322 362. 5 248. 5 242. 9 221. 5 299. 9
323 363. 6 249. 3 243. 7 222. 2 300. 9
324 364. 8 250. 1 244. 4 222. 9 301. 8
325 365. 9 250. 9 245. 2 223. 7 302. 7
326 367. 0 251. 6 246. 0 224. 4 303. 6
327 368. 2 252. 4 246, 8 225. 1 304. 6
328 369. 3 253. 2 247. 6 225. 8 305. 5
329 370. 4 254. 0 248. 4 226. 6 306. 5
330 371. 5 254, 8 249. 2 227. 3 307. 4
331 372. 7 255. 6 250. 0 228. 0 308. 3
332 373. 8 256. 4 250. 7 228. 8 309. 3
333 374. 9 257. 1 251. 5 229. 5 310, 2
334 376. 0 257. 9 252. 3 230. 2 311. 2
335 377. 2 258. 7 253. 0 230. 9 312. 1
336 378. 3 259. 5 253. 8 231. 7 313. 0
337 379. 4 260. 3 254. 6 232. 4 314. 0
338 380. 5 261. 1 255.4 233. 1 314, 9
339 381. 7 261. 9 256. 2 233. 8 315. 8
340 382. 8 262. 7 257. 0 234. 6 316. 8
341 383. 9 263. 4 257. 7 235. 3 3.17. 7
342 385. 0 264. 2 258. 5 236. 0 3.18. 6
343 386. 2 265. 0 259. 3 236. 7 319, 6
344 387. 3 265. 8 260. 0 237. 5 320. 5
345 388. 4 266. 6 260. 8 238. 2 321. 4
346 389. 5 267. 4 261. 6 238, 9 322. 4
347 390. 7 268. 2 262. 4 239. 7 323. 3
348 391. 8 269. 0 263. 2 240. 4 324. 3
349 392. 9 269. 7 263. 9 241. 1 325. 2
350 394. 0 270. 5 264. 7 241. 9 326. I
351 395. 2 271. 3 265. 5 242. 6 327. 0
352 396. 3 272. 1 266. 3 243. 3 328. O
353 397. 4 272. 9 267. 1 244. 1 328, 9
354 398. 5 273. 7 267. 9 244. 8 329. 9
355 399. 7 274. 5 268. 7 245. 5 330, 8
356 400. 8 275. 3 269. 5 246. 2 331. 7
357 401. 9 276. 0 270. 2 247. 0 332. 7
358 403. 1 276. 8 271. 0 247. 7 333. 6
359 404. 2 277. 6 27.1. 8 248. 4 334. 5
360 405. 3 278. 4 272. 5 249. 2 335. 5
361 406. 4 279. 2 273. 3 249. 9 336. 4
362 407. 6 280. 0 274. 1 250, 7 337. 3
363 408. 7 280. 8 274. 9 251. 4 338. 3
364 409. 8 281. 6 275. 7 252. 1 339. 2
See footnotes at end of table.
580
Circular of the National Bureau of Standards
TABLE 78.-Reducing-sugar values by the Munson anh Walker method–Continued
Values of National Bureau of Standards (Hammond)
Invert Sugar and sucrose
Cuprous Invert
Copper oxide DextroSe Sugar Levulose
0.3 g of total 0.4 g of total 2.0 g of total
Sugar Sugar Sugar
Tng Tng Tng Tng 7\g mg mg Tng
365 410. 9 193. 8 || 200. 8 200. 1 199. 9 195. 1 207. 7
366 412. 1 194. 4 201. 4 200. 7 200. 5 195. 7 208. 3
367 413. 2 195.0 202. 0 201. 3 201. 1 196. 3 209. 0
368 414. 3 195. 6 202. 6 201. 9 201. 7 196. 9 209. 6
369 415. 4 || 196. 2 | 203. 2 202. 5 202. 4 197. 6 210. 2
370 416. 6 196. 8 || 203. 8 203. 1 203. 0 198. 2 210, 8
371 417. 7 | 197. 4 || 204. 4 203. 7 203. 6 198. 8 211. 4
372 418. 8 198.0 | 205. 0 204. 3 204. 2 199. 4 212. 0
373 419. 9 198. 5 205. 7 204. 9 204, 8 200. 0 212. 6
374 421. 1 199. 1 206. 3 205. 6 205. 4 200. 7 213. 3
375 422. 2 199. 7 | 206. 9 206. 2 206. 0 201. 3 213. 9
376 423. 3 | 200. 3 | 207. 5 206. 8 206. 6 201. 9 214. 5
377 424. 4 200. 9 208. 1 207. 4 207. 3 202. 5 215. 1
378 425. 6 || 201. 5 | 208. 7 208. 0 207. 9 203. 1 215. 7
379 426. 7 | 202. 1 209. 3 208. 6 208. 5 203. 8 21 6. 3
380 427. 8 202. 7 || 209. 9 209. 2 209. 1 204. 4 217. 0
381 428. 9 203. 3 || 210. 5 209. 8 209. 7 205. 0 217. 6
382 430. 1 | 203. 9 || 21 1. 1 210. 4 210. 3 205. 6 218. 2
383 431. 2 204. 5 || 211. 8 211. 1 211. 0 206. 3 218. 8
384 432. 3 || 205. 1 212.4 211. 7 211. 6 206. 9 219. 5
385 433. 5 | 205. 7 || 213. 0 212. 3 212. 2 207. 5 220. 1
386 434. 6 206. 3 || 213. 6 212. 9 212. 8 208. 1 220. 7
387 435. 7 | 206. 9 || 214. 2 213. 5 213. 4 208. 8 221. 3
388 436. 8 || 207. 5 || 214. 8 214. 1 214. 0 209. 4 221. 9
389 438. 0 || 208. 1 215. 4 214. 7 214. 7 210. 0 222. 6
390 439. 1 208. 7 || 216. 0 215. 4 215. 3 210. 6 223. 2
391 440. 2 209, 3 || 216. 7 216. 0 215. 9 211. 3 223. 8
392 441. 3 209, 9 217. 3 216. 6 216. 5 211. 9 224. 4
393 442. 5 210. 5 || 217. 9 217. 2 217. 1 212. 5 225. 1
394 443. 6 211. 1 218. 5 217. 8 217. 8 213. 2 225. 7
395 444. 7 || 211. 7 || 219. 1 218. 5 218. 4 213. 8 226. 3
396 445. 8 || 212. 3 || 219. 8 219. 1 219. 0 214. 4 226. 9
397 447. 0 212. 9 220. 4 219. 7 219. 6 215. 1 227. 6
398 448. 1 213. 5 221. 0 220. 3 220. 3 215. 7 228. 2
399 449. 2 | 214. 1 221. 6 220. 9 220. 9 216. 3 228. 8
400 450. 3 214. 7 || 222. 2 221. 5 221. 5 217. () 229. 4
401 451. 5 215. 3 222. 9 222, 2 222. 1 217. 6 230. 1
402 452. 6 215. 9 || 223. 5 222. 8 222. 8 218. 2 230. 7
403 453. 7 216. 5 224. 1 223. 4 223. 4 218. 9 231. 3
404 454. 8 || 217. 1 224. 7 224. 0 224. 0 219. 5 232. 0
405 456. 0 || 217. 8 225. 4 224, 7 224. 7 220. 1 232, 6
406 457. 1 218. 4 226. 0 225. 3 225. 3 220. 8 233. 2
407 458. 2 219. 0 || 226. 6 225. 9 225. 9 || 221. 4 233. 9
408 459. 3 || 219. 6 227. 2 226. 6 226. 5 222. 0 234. 5
409 460. 5 220. 2 227. 9 227, 2 227. 2 222. 7 1
235.
Polarimetry, Saccharimetry, and the Sugars
581
TABLE 78.—Reducing-sugar values by the Munson and Walker method—Continued
Values of Straughn and Given
Values of
Walker
Lactose.H2O and sucrose
Copper Cuprous oxide Lactose.H2O Maltose.H2O
1 lactose 1 lactose
4 SucroSe 12 SuCrOSe
Tng Tng Tng 7ng Tng Tng
365 410. 9 282. 4 276, 5 252. 9 340. 2
366 412. 1 283. 2 277. 3 253. 6 341. 1
367 413. 2 284. 0 278. 0 254. 3 342. 0
368 414. 3 284.8 278. 8 255. 1 343. 0
369 415. 4 285. 6 279. 6 255. 8 343. 9
370 416. 6 286. 4 280. 4 256. 5 344. 8
3.71 417. 7 287. 2 281. 2 257. 3 345. 8
372 418. 8 288. 0 282. 0 258. 0 346, 7
373 419, 9 288. 8 282, 8 258. 7 347. 6
374 421. 1 289. 5 283. 5 259, 5 348. 5
375 422. 2 290. 3 284. 3 260. 2 349. 5
376 423. 3 291. 1 285. 1 260. 9 350. 5
377 424. 4 291. 9 285. 9 261. 7 351. 4
378 425. 6 292. 7 286, 7 262, 4 352. 3
379 426. 7 293. 5 287. 5 263. 2 353. 2
380 427, 8 294, 3 288. 3 263. 9 354. 2
381 428, 9 295. 1 289. 1 264. 6 355. 1
382 430, 1 295. 8 289. 8 265. 4 356. 0
383 431. 2 296. 6 290. 6 266. 1 357. 0
384 432. 3 297. 4 291. 4 266. 9 357. 9
385 433. 5 298. 2 292. 2 267. 6 358, 9
386 434. 6 299. 0 293. 0 268. 4 359. 8
387 435. 7 299. 8 293. 8 269. 1 360. 7
388 436. 8 300. 6 294, 6 269, 9 361. 7
389 438. 0 301.4 295. 4 270. 6 362. 6
390 439. 1 302. 1 296. 1 271. 3 363. 5
391 440, 2 302. 9 296. 9 272. 1 364. 5
392 441. 3 303. 7 297. 7 272. 8 365. 4
393 442. 5 304. 5 298. 5 273. 6 366. 3
394 443. 6 305. 3 299. 3 274. 3 367. 3
395 444. 7 306. 1 300. 1 275. 1 368. 2
396 445. 8 306. 9 300. 9 275. 8 369. 1
397 447. 0 307. W 301. 7 276. 6 370. 1
398 448. 1 308. 5 302. 5 277. 3 371. 0
399 449. 2 309. 3 303. 2 278. 1 371. 9
400 450. 3 310. 1 304. 0 278. 8 372. 9
401 451. 5 310. 9 304.8 279. 5 373. 8
402 452. 6 311. 7 305. 6 280. 3 374. 7
403 453. 7 312.5 306. 4 281. 0 375. 7
404 454. 8 313. 3 307. 2 281. 8 376, 6
405 456. 0 314. 1 308. 0 282. 5 377. 6
406 457. 1 314. 9 308. 8 283. 2 378. 5
407 458. 2 315. 7 309. 5 284. 0 379. 4
408 459. 3 316. 4 310, 3 284. 8 380. 3
409 460. 5 2 31.1. 1 285. 5 381. 3
317.
See footnotes at end of table.
582
Circular of the National Bureau of Standards
TABLE 78.-Reducing-sugar values by the Munson and Walker method–Continued
Values of National Bureau of Standards (Hammond)
|
|
Invert Sugar and Sucrose
Cuprous Invert
Copper oxide Dextrose Sugar Levulose
0.3 g of total 0.4 g of total 2.0 g of total
Sugar Sugar Sugar
Ing Ing Illg ing ing ng Tng Illg
4 10 461. 6 220. 8 228. 5 227. 8 227. 8 223. 3 235. 8
41 I 462. 7 221. 4 229. 1 228. 4 228. 4 224. 0 236. 4
412 463. 8 222. 0 229. 7 229, 1 229, 1 224, 6 237. 1
413 465. 0 222. 6 230. 4 229. 7 229. 7 225. 3 237, 7
414 466. 1 223. 3 231. 0 230. 4 230. 4 225. 9 238. 4
4.15 467. 2 223. 9 231. 7 231. 0 231. 0 226. 6 239. 0
416 468. 4 224. 5 232. 3 231. 6 231. 7 227. 2 239, 7
4.17 469. 5 225. 1 232. 9 232. 3 232. 3 227. 8 240. 3
4.18 470. 6 225. 7 233. 6 232, 9 232, 9 228. 5 241. 0
419 471. 7 226. 3 234. 2 233. 5 233. 6 229, 1 241. 6
420 472. 9 227. 0 234. 8 234. 2 234. 2 229. 8 242. 2
421 474. () 227. 6 235. 5 234. 8 234, 9 230. 4 242, 9
422 475. I 228. 2 236. I 235. 5 235. 5 231. 1 243. 6
423 476. 2 228. 8 236. 8 236. 2 236. 2 231. 8 244. 3
424 477. 4 229. 5 237. 5 236. 8 236. 9 232. 4 244. 9
425 478. 5 230. 1 238. I 237. 5 237. 5 233. 1 245, 6
426 479. 6 230. 7 238. 8 238. 2 238. 2 233. 8 246. 3
427 480. 7 231.4 239. 5 238. 8 238. 9 234. 5 247. 0
428 481. 9 232. 0 240. 2 239. 5 239. 6 235. 1 247. 8
429 483. 0 232. 7 240, 8 240. 2 240. 3 235. 8 248. 5
430 484. 1 233. 3 241. 5 240. 9 241. 0 236. 5 249. 2
431 485. 2 234. 0 242. 3 241. 7 241. 7 237. 2 250. 0
432 486. 4 234, 7 243. () 242. 4 242. 5 238. 0 250. 8
433 487. 5 235. 3 243. 8 243. 2 243. 3 238. 7 251, 6
434 488. 6 236. 1 244. 7 244. 1 244. 2 239. 6 252. 7
435 489. 7 236, 9 245. 6 245. 1 245. 1 240. 4 253, 7
1 L. S. Munson and P. H. Walker, J. Am. Chem. Soc. 28, 663 (1906).
2 L. D. Hammond, J. Research NBS 24, 589 (1940) RP1301.
Polarimetry, Saccharimetry, and the Sugars
583
TABLE 78.—Reducing-sugar values by the Munson and Walker method— Continued
Values of Straughn and Given
Values of
Walker
Lactose.H2O and sucrose
Copper Cuprous oxide Lactose.H2O - - Maltose. H2O .
1 lactose 1 lactose
4 SuCrOSè 12 SuCrOSé
Illg Tilg Tng Tilg Tng Tng
410 461. 6 3.18. 0 311. 9 286. 2 382. 2
41 1 462. 7 3.18. 8 312. 7 287. 0 383. 1
412 463. 8 3.19. 6 313. 5 287. 8 384. 1
413 465. 0 320. 4 314. 3 288. 5 385. 0
414 466. 1 321. 1 315. 1 289. 2 386. 0
415 467. 2 321. 9 315. 8 290. 0 386. 9
416 468. 4 322. 7 316. 6 290. 8 387. 8
4.17 469. 5 323. 5 317. 4 291. 5 388, 7
4.18 470. 6 324, 3 318. 1 292. 2 389. 7
419 471. 7 325, 1 3.18. 9 293. 0 390. 6
420 472. 9 325, 9 3.19. 7 293. 7 391. 6
42 l 474. 0 326. 7 320. 5 294. 5 392. 5
422 475. I 327. 5 321. 3 295. 2 393. 4
423 476. 2 328. 3 322. 1 296. 0 394. 4
424 477. 4 329. 1 322. 8 296. 7 395. 3
425 478. 5 329. 9 323. 6 297. 5 396. 2
426 479. 6 330. 7 324. 4 298. 2 397. 1
427 480. 7 331. 5 325. 2 299. 0 398. 1
428 481. 9 332. 3 326. 0 299. 7 399. 0
429 483. 0. 333. 1 326. 8 300. 4 400. 0
430 484. 1 333. 9 327. 6 301. 2 400. 9
431 485. 2 . 334. 7 328. 4 302. 0 401. 8
432 486. 4 335. 5 329. 2 302. 7 402. 7
433 487. 5 336. 2 330. 0 303. 5 403. 7
434 488. 6 337. 0 330. 7 304. 2 404. 6
435 489, 7 337. 8 331. 5 305. 0 405. 6
3 A. Given, Methods for Sugar Analysis (P. Blakiston’s Sons & Co., Philadel-
phia, Pa., 1912).
4 P. H. Walker, J. Am. Chem. Soc. 29, 541 (1907).
5 The values in the table for concentrations of reducing sugar less than 20 mg
are extrapolated and should be used with caution and only for approximate
determinations.
584 Circular of the National Bureau of Standards
TABLE 79.-Allihn table for the determination of deactrose
Cop- º. Dex- Cop- 9. Dex- Cop- $º. Dex. Cop. .9. Dex.
per | . . trose per | . trose per | . trose per | . trose
Tng mg Tmg 7ng mg 7mg 7mg mg 7ng 7mg | 7mg img
11 12.4 6. 6 76 85. 6 38.8 141 158.7 71.8 206 231. 9 105.8
12 13. 5 7. 1 77 86. 7 39. 3 142 159.9 72. 3 207 233. 0 106.3
13 14.6 7. 6 78 87.8 39.8 143 161. 0 72.9 208 234. 2 106.4
14 15.8 8. 1 79 88.9 40. 3 144 162. 1 73. 4 209 235. 3 107.9
15 16.9 8. 6 80 90. 1 40.8 145 163.2 73.9 210 236.4 107.8
16 18.0 9. 0 81 91. 2 41.3 146 164.4 74. 4 211 237. 6 108.4
17 19. 1 9, 5 82 92.3 41.8 147 165. 5 74. 9 212 238.7 109.0
18 20.3 10. 0 83 93.4 42. 3 148 166.6 75. 5 213 239. 8 109.5
19 21.4 10.5 84 94.6 42.8 149 167.7 76. 0 214 240. 9 110. 0
20 22.5 11.0 85 95.7 43.4 150 168.9 76.5 215 242, 1 110.6
21 23. 6 11. 5 86 96.8 43.9 151 170. 0 77.0 216 243.2 111. 1
22 24.8 12. 0 87 97. 9 44.4 152 171. 1 77.5 217 244.3 111. 6
23 25.9 12.5 88 99.1 44.9 153 172. 3 78.1 218 245.4 112. 1
24 27.0 13.0 89 100. 2 45.4 154 173.4 78.6 219 246. 6 112.7
25 28. 1 13. 5 90 101.3 45.9 155 174.5 79. 1 220 247. 7 113.2
26 29.3 14. () 91 102.4 46.4 156 175. 6 79.6 221 248. 7 113. 7
27 30.4 14.5 92 103. 6 46.9 157 176.8 80. 1 222 249. 9 114.3
28 31. 5 15. 0 93 104.7 47.4 158 177. 9 80. 7 223 251.0 114.8
29 32.7 15.5 94 105.8 47. 9 159 179. 0 81.2 224 252.4 115. 3
30 33.8 16.0 95 107.0 48. 4 160 180. I 81. 7 225 253. 3 115.9
31 34.9 16.5 96 108.1 48.9 161 181. 3 82.2 226 254.4 116.4
32 36.0 17. G 97 109. 2 49.4 162 182.4 82.7 227 255. 6 116.9
33 37.2 17. 5 98 110.3 49. 9 163 183. 5 83.3 228 256. 7 117.4
34 38. 3 18.0 99 111. 5 50.4 164 184. 6 83.8 229 || 257.8 118.0
35 39.4 18.5 100 112. 6 50.9 165 185.8 84.3 230 258.9 118. 5
36 40. 5 18.9 101 113. 7 51.4 166 | 186.9 84.8 231 260. 1 119. 0
37 41, 7 19.4 102 114.8 51.9 167 188.0 85.3 232 261.2 119.6
38 42.8 19.9 103 116.0 52.4 168 189. 1 85.9 233 262. 3 120. 1
39 43.9 20.4 104 117. 1 52.9 169 190.3 86. 4 234 263.4 120. 7
40 45.0 20. 9 105 118.2 53.5 170 191.4 86.9 235 264, 6 121.2
41 46.2 21.4 106 119. 3 54.0 171 192. 5 87.4 236 265. 7 121. 7
42 47. 3 21.9 107 120. 5 54. 5 172 193. 6 87. 9 237 266, 8 122. 3
43 48.4 22.4 108 121.6 55. 0 173 194.8 88. 5 238 268.0 122.8
44 49.5 22.9 109 122. 7 55. 5 174 195.9 89.0 239 269, 1 123.4
45 50. 7 23.4 110 123. 8 56.0 175 197. 0 89.5 240 270. 2 123.9
46 51.8 23.9 111 125. 0 56.5 176 198. 1 90.0 241 271. 3 124.4
47 52.9 24.4 112 126. 1 57. 0 177 199.3 90. 5 242 272.5 125. 0
48 54.0 24. 9 113 127. 2 57. 5 178 200.4 91. 1 243 273. 6 125. 5
49 55.2 25.4 114 128. 3 58. 0 179 || 201. 5 91.6 244 274. 7 126.0
50 56.3 25, 9 115 129. 6 58.6 180 | 202. 6 92.1 245 || 275.8 126.6
51 57.4 26.4 116 130. 6 59. 1 181 203. 8 92.6 246 277. 0 127. 1
52 58. 5 26.9 117 131. 7 59. 6 182 | 204.9 93. 1 247 278. 1 127. 6
53 59.7 27.4 118 132.8 60. 1 183 206. 0 93.7 248 279. 2 128. 1
54 60, 8 27. 9 119 134. 0 60.6 184 207. 1 94.2 249 280. 3 128.7
55 61.9 28.4 120 135. I 61. 1 185 | 208. 3 94.7 250 281. 5 129, 2
56 63.0 28.8 121 136.2 61. 6 186 | 209. 4 95.2 251 282, 6 129. 7
57 64. 2 29.3 122 137.4 62. 1 187 210.5 95.7 252 283. 7 130.3
58 65.3 29.8 123 138. 5 62. 6 188 211. 7 96.3 253 284.8 130.8
59 66.4 30.3 124 139. 6 63. 1 189 212.8 96.8 254 286. 0 131.4
60 67. 6 30.8 125 140. 7 63. 7 190 213.9 97.3 255 287. 1 131.9
61 68.7 31. 3 126 141.9 64. 2 191 215. 0 97.8 256 288, 2 132.4
62 69.8 31.8 127 143.0 64. 7 192 216.2 98.4 257 289.3 133. 0
63 70. 9 32.3 128 144. 1 65. 2 193 217.3 98.9 258 290. 5 133. 5
64 72. 1 32.8 129 145.2 65. 7 194 218.4 99.4 259 291. 6 134, 1
65 73. 2 33.3 130 146.4 66. 2 195 || 219. 5 100.0 260 292. 7 134.6
66 74. 3 33.8 131 147. 5 66.7 196 220. 7 100. 5 261 293.8 135. 1
67 75.4 34.3 132 148. 6 67. 2 197 221.8 101.0 262 295.0 135. 7
68 76. 6 34.8 133 149. 7 67.7 198 || 222.9 101.5 623 296. 1 136.2
69 77.7 35. 3 134 150. 9 68. 2 199 224.0 102.0 264 297.2 136.8
70 78.8 35.8 135 152.0 68. 8 200 225, 2 102.6 265 298.3 137. 3
71 79.9 36. 3 136 153. 1 69. 3 201 226. 3 103.1 266 299. 5 137.8
72 81. 1 36, 8 137 154. 2 69.8 202 || 227.4 103.7 267 || 300. 6 138.4
73 82.2 37. 3 138 155.4 70.3 203 228. 5 104.2 268 301. 7 138.9
74 83.3 37.8 139 156. 5 70. 8 204 || 229. 7 104.7 269 302.8 139. 5
75 84.4 38. 3 140 157.6 71. 3 205 230.8 105.3 270 304. 0 140. 0

Polarimetry, Saccharimetry, and the Sugars
TABLE 79.—Allihn table for the determination of dea:trose—Continued



Cu- Cu- Cu- Cu-
Cop- Dex- Cop- Dex- Cop Dex- Cop- Dex-
per . troSe per . troSe per- . troSe Der. . troSe
mg 7ng 7mg 7mg 7mg 7mg 7mg 7mg 7ng 7mg 7mg 7mg
271 305. 1 140. 6 320 360. 3 167. 5 369 415.4 195. 1 418 470. 6 223. 3
272 306.2 141. 1 321 361.4 168. 1 370 416. 6 195.7 419 471. 8 223.9
273 3()7. 3 141. 7 322 362.5 168. 6 371 417.7 196.3 420 472.9 224. 5
274 308. 5 142. 2 323 363. 7 169.2 37 418.8 196.8 421 474. 0 225. 1
275 309.6 142.8 324 364, 8 169. 7 373 420. 0 197. 4 422 475. 6 225.7
276 310. 7 143.3 325 365.9 170.3 374 421. 1 198. 0 423 476.2 226.3
277 311.9 143.9 326 367.0 170.9 375 422, 2 198.6 424 477.4 226.9
278 313. 0 144.4 327 368. 2 171.4 376 423.3 199. 1 425 478.5 227. 5
270 314. 1 145. 0 328 369. 3 172.0 377 424. 5 199.7 426 479. 6 228. 0
280 315.2 145.5 329 370. 4 172. 5 378 425. 6 200.3 427 480. 7 228. 6
281 316.4 146.1 330 371.5 173. 1 379 426.7 200.8 428 481.9 229. 2
282 317. 5 146.6 331 372.7 173.7 380 427.8 201.4 429 483. 0 229.8
283 3.18.6 147.2 332 373. 8 174.2 381 429. 0 202.0 430 484. I 230.4
284 319.7 147.7 333 374. 9 174, 8 382 430. 1 202. 5 431 485. 3 231. 0
285 320. 9 148. 3 334 376. 0 175.3 383 431, 2 203. 1 432 486.4 231. 6
286 322.0 148.8 335 377.2 175.9 384 432.3 203.7 433 487. 5 232.2
287 323. 1 149.4 336 378. 3 176. 5 385 433.5 204.3 434 488.6 232.8
288 324.2 149.9 337 379. 4 177.0 386 434.6 204.8 435 489. 7 233.4
289 325.4 150. 5 338 380. 5 177. 6 387 435. 7 205. 4. 436 490. 9 233.9
290 326. 5 151. 0 339 381. 7 178. 1 388 436.8 206. () 437 492.0 234. 5
291 327.4 151. 6 340 382.8 178.7 389 438. 0 206. 5 438 493. 1 235. 1
292 328.7 152. 1 341 383.9 179.3 390 439. 1 207. 1 439 494.3 235. 7
293 329.9 152.7 342 385. 0 179.8 391 440.2 207.7 440 495. 4 236. 3
294 331.0 153. 2 343 386. 2 180. 4 392 441. 3 208. 3 441 496. 5 236.9
295 332.1 153.8 344 387.3 180. 9 393 442.4 208. 8 442 497. 6 237.5
296 333.3 154.3 345 388. 4 181.5 394 443.6 209.4 443 498.8 238. 1
297 334.4 154. 9 346 389. 6 182. 1 395 444.7 210. 0 444 499.9 238.7
298 335. 5 155.4 347 390. 7 182. É 396 445.9 210. 6 445 501. 0 239. 3
299 336.6 156. 0 348 391.8 183.2 397 447. () 211. " 446 502. 1 239.8
300 337.8 156.5 349 392.9 183. 7 398 448. 1 211. Y 447 503. 2 240.4
301 338.9 157. 1 350 394. () 184.3 399 449. 2 212. 3 448 504.4 241. 0
302 340. 0 157.6 351 395. 2 184. 9 400 450.3 212.9 449 505. 5 241. 6
303 341. 1 158. 2 352 396.3 185.4 401 451. 5 213. 5 450 506. 6 242.2
304 342. 3 158.7 353 397. 4 186.0 402 452. 6 214. 1 451 507. 8 242.8
354 398. 6 186. 6 403 453. 7 214.6 452 508. 9 243. 4
305 343. 4 159. 3
306 344. 5 159.8 355 399. 7 187.2 404 454. S 215.2 453 510. 0 244. 0
307 345.6 160.4 356 400. 8 187. 7 405 456. () 215.8 454 511. I 244.6
308 346.8 160. 9 357 401.9 188. 3 406 457. 1 216.4 455 512. 3 245.2
309 347. 9 161. 5 358 403. 1 188.9 407 458. 2 217.0 456 513. 4 245.7
408 459, 4 217. 5 457 514. 5 246. 3
310 349. 0 162. 0 359 404. 2 189.4
3.11 350. 1 162. 6 360 405. 3 190. 0 400 460. 5 218. 1 458 515. 6 246.9
312 351.3 163. 1 361 406, 4 190.6 410 461. 6 218.7 459 516.8 247. 5
313 352.4 163. 7 362 407. 6 191. 1 411 462.7 219. 3 460 517. 9 248. 1
314 353. 5 164. 2 363 408.7 191. 7 412 463.8 219.9 461 519. () 248. 7
462 520. 1 249.3
315 354.6 164.8 364 409. 8 192. 3 413 465. 0 220.4
316 355.8 165.3 365 410. 9 192.9 414 466. 1 221.0 463 521.3 249. 9
317 356.9 165.9 366 412. 1 193.4 415 467. 2 221. 6
3.18 358.0 166.4 367 413. 2 194. 0 416 468.4 222, 2
319 359. 1 167. 0 368 414. 3 194.6 417 469, 5 222. 3
586
Circular of the National Bureau of Standards
TABLE 80.-Calculation of deactrose, levulose, invert sugar, lactose, and maltose
(Quisumbing and Thomas copper equivalents)
h
Cupro-
Cop- U1S OX- Dex- Levu- Invert
per ide troSe lose Sugar
mg mg mg mg ng
10 11. 3 4, 8 5. 3 5. 0
20 22. 5 9. 5 10. 5 10. 1
30 33. 8 14. 3 15. 8 15. 2
40 45. () 19. 1 21, 2 20. 3
50 56. 3 24. 0 26. 5 25. 4
60 67. 6 28. 9 31. 9 30. 6
70 78. 8 33. 7 37. 2 35. 7
80 90. 1 38. 7 42. 6 40. 9
90 | 101. 3 43. 6 48. () 46. 1
100 || 112, 6 48. 6 53. 4 51. 3
110 | 123. 8 53. 5 58. 8 56. 5
120 | 135. 1 58. 5 64. 3 61. 8
130 | 1.46. 4 63. 6 70. 7 67. 0
140 | 157. 6 68. 6 75. 2 72, 3
150 | 168. 9 73. 7 80. 7 77. 6
160 | 180. 1 78. 8 86. 2 82. 9
170 191. 4 83. 9 91. 7 88. 3
180 202. 6 89. I 97. 2 93. 7
190 213. 9 94. 2 102. 8 99. I
200 225, 2 99. 4 108. 4 104. 4
210 || 236. 4 || 104. 6 | 14. () 109. 8
220 247. 7 || 109. 9 | 19. 6 | 15. 2
230 || 258. 9 || 1 |5. 1 125. 2 120. 6
240 270. 2 | 120. 4 |30. 8 |26. I
250 281. 5 | 125. 7 136. 4 131. 6
260 292. 7 || 131. 0 142. 1 137. 1
270 304. 0 || 136. 4 || 1.47. 8 14.2. 6
280 315. 2 | 1.41. 7 153. 5 148. 2
290 326. 5 | 1.47. 1 159. 2 153. 7
300 337. 8 || 152. 6 165. 0 159. 3
310 || 349. 0 || 158. 0 170. 7 164. 9
320 || 360. 3 | 163. 5 176. 5 170. 5
330 371. 5 | 168. 9 182. 3 176. 1
340 || 382. 8 || 174. 5 188. 1 18.1. 8
350 394. 0 || || 80. 0 193. 9 187. 4
360 | 405. 3 | 185. 5. 199. 7 193. 1
370 || 416. 6 191. 1 205. 5 198. 8
380 || 427. 8 || 196. 7 211. 4 204. 5
390 || 439. 1 || 202. 3 217. 3 210. 2
400 || 450. 3 || 208. 0 223. 2 216. 0
410 || 46 ſ. 6 || 213. 7 229. 1 221. 8
420 472. 9 || 219. 4 235. 0 227. 6
430 || 484. 1 225. 1 240. 9 233. 4
440 || 495. 4 || 230. 8 246. 9 239. 2
450 506. 6 || 236. 6 252. 9 245. 0
460 || 517. 9 || 242. 4 258. 9 250. 9
470 529. 1 || 248. [ 264. 9 256. 8
480 || 540. 4 || 253. 8 270. 9 262. 7
Lactose Maltose
C12H22 C12H22 C12H22 C12H22
Oil O11. H2O O11 11. He
mg ng mg mg
7.7 8, 1 9. 4 9. 9
15. 5 16. 3 18. 8 19. 8
23. 2 24. 4 28, 2 29. 7
30. 9 32. 5 37. 6 39. 6
38. 7 40. 7 47. 0 49. 5
46. 4 48. 8 56.4 59. 4
54. () 56, 9 65. 8 69. 3
61. 7 65. () 75. 2 79. 2
69. 5 73. 2 84. 6 89. I
77. 2 81. 3 94. 0 99. 0
85. 0 89. 5 103. 4 108. 9
92. 7 97. 6 112. 8 118. 8
100. 4 105. 7 122. 2 128. 7
108. 2 113. 9 131. 6 138. 6
116. 0 122. 0 141, 0 148. 5
123. 7 130. 1 150. 4 158. 4
131. 4 138. 3 159. 8 168. 3
139. 1 146. 4 169. 2 178. 2
146. 9 154. 6 178. 8 188. ſ.
154, 6 162. 7 188. 2 198. ()
162. 3 | 70. 9 197. 6 20.7. 9
170. 0 179. 0 207. 0 217. 8
177. 8 187. 2 216. 4 227, 7
185. 5 195. 3 225. 8 237. 6
193. 2 203. 4 235. 2 247. 5
201. 0 211. 6 244, 6 257. 4
208. 8 219. 8 254. 0 267. 3
216. 5 227. 9 263. 4 277. 2
224. 2 236. 0 272. 8 287. 1
232. 0 244. 2 282. 2 297. ()
239. 7 252. 3 291. 6 306. 9
247. 5 260. 5 301. 0 316. 8
255. 3 268. 7 310. 4 326. 7
263. 0 276. 8 319. 8 336. 6
270. 7 285. 0 329. 2 346. 5
278. 4 293. 1 338. 6 356. 4
286. 2 301. 3 348. 0 366. 3
293. 9 309. 4 357. 4 376. 2
301. 6 317. 5 366. 8 386. 1
309. 4 325. 7 376. 2 396. 0
317. 1 333. 8 385. 6 405. 9
324. 9 342. 0 395. 0 415. 8
332. 6 350. 1 404. 4 425. 7
340. 4 358. 3 413. 8 435. 6
348. 1 366. 4 423. 2 445. 5
355. 9 374. 6 432. 6 455. 4
363. 6 382. 7 442. 0 465. 3
371. 3 390. 9 451. 4 475. 2
Polarimetry, Saccharimetry, and the Sugars
587
TABLE 81.—Bertrand table for reducing sugars
A. DETERMINATION OF INVERT stººgoose, GALACTOSE, MALTOSE, AND
AC

Weight of copper corresponding to— Weight of copper corresponding to—
Milli- Milli-
grams of grams of
Sugar || Invert | Glu- || Galac- |Maltose I actose | of sugar || Invert | Glu- || Galac- |Maltose Lactose
Sugar COSé tose anhyd anhyd Sugar COSe tose anhyd anhyd
ng Cu mg Cu mg Cu mg Cu mg Cu ng Cu mg Cu mg Cu mg Cu mg Cu
10 20.6 20.4 19. 3 11.2 14.4 56 105.7 105.8 101, 5 61.4 76. 2
11 22. 6 22.4 21. 2 12. 3 15.8 57 107.4 107. 6 103.2 62. 5 77.5
12 24.6 24.3 23. 0 13. 4 17.2 58 109. 2 109.3 104.9 63. 5 78.8
13 26. 5 26. 3 24.9 14.5 18.6 59 110.9 || 1 || 1. 1 106.6 64. 6 80. 1
14 28. 5 28. 3 26. 7 15. 6 20. 0 60 112.6 112. 8 108. 3 65. 7 81.4
15 30. 5 30.2 28. 6 16. 7 21.4 61 114.3 114. 5 110. () 66. 8 82.7
16 32. 5 32. 2 30. 5 17.8 22.8 62 115.9 1 16. 2 111. 6 67. 9 83.9
17 34. 5 34. 2 32. 3 18, 9 24.2 63 || 117. 6 117. 9 || 113. 3 68.9 85. 2
18 36.4 36, 2 34. 2 20. 0 25. 6 64 119. 2 119. 6 115. () 70. 0 86. 5
19 38.4 38. 1 36.0 21. 1 27.0 65 120. 9 121. 3 116. 6 71. 1 87.7
20 40.4 40. 1 37. 9 22, 2 28.4 66 122. 6 123. () 118. 3 72. 2 89.9
21 42. 3 42. 0 39.7 23. 3 29.8 67 124. 2 | 124. 7 || 120. 0 73. 3 90.3
22 44.2 43.9 41.6 24.4 31. 1 68 125.9 126.4 121. 7 74. 3 91.6
24 48. 0 47. 7 45.2 26. 6 33.9 69 || 127. 5 | 128. 1 123. 3 75.4 92.8
25 49.8 49. 6 47. 0 27.7 35. 2 70 129. 2 129, 8 125. 0 76.5 94. 1
26 51. 7 51. 5 48.9 28.9 36. 6 71 130.8 131.4 126.6 77. 6 95.4
27 53. 6 53. 4 50. 7 30. 0 38.0 72 132.4 133. 1 128. 3 78.6 96.9
28 55. 5 55. 3 52.5 31. 1 39. 4 73 134. 0 134. 7 130. 0 79. 7 98.0
29 57. 4 57.2 54. 4 32.2 40. 7 74 135, 6 136. 3 131. 5 80.8 99. I
30 59. 3 59. 1 56. 2 33.3 42. 1 75 137, 2 137, 9 133. 1 81.8 100.4
31 61. 1 60. 9 58. () 34.4 43.4 76 138.9 139, 6 134.8 82.9 101.7
32 63.0 62.8 59, 7 35. 5 44.8 77 140. 5 141. 2 136.4 84. 0 102.9
33 64.8 64, 6 61. 5 36. 5 46. 1 78 142. I 142.8 138. () 85. 1 104. 2
34 66.7 66. 5 63. 3 37.6 47.4 79 143. 7 144. 5 139.7 86. 1 105. 4
35 68. 5 68. 3 65. 0 38. 7 48. 7 80 145.3 146. I 141. 3 87.2 106.7
36 70.3 70. 1 66. 8 39.8 50. I 81 146.9 147, 7 142.9 88.3 107.9
37 72. 2 72. 0 68. 6 40. 9 51.4 82 148. 5 149.3 144.6 89.4 109. 2
38 74. 0 73. 8 70. 4 41.9 52.7 83 150. 0 || 150. 9 || 146.2 90.4 1 10.4
39 75.9 75. 7 72. 1 43. 0 54. 1 84 151.6 I 52.5 147.8 91.5 111. 7
40 77.7 77.5 73.9 44. 1 55. 4 85 153. 2 154. 0 149.4 92. 112.9
41 79.5 79.3 75. 6 45. 2 56.7 86 154.8 155. 6 151. I 93.7 114. I
42 81.2 81. 1 77.4 46. 3 58. 0 87 156.4 157.2 152. 7 94.8 115. .
43 83. 0 82.9 79. 1 47. 4 59. 3 88 157. 9 158. 8 154.3 95. 8 116. 6
44 84.8 84. 7 80.8 48. 5 60. 6 89 || || 59.5 | 160. 4 || 156.0 96.9 117. 9
45 86. 5 86.4 82. 5 49. 5 61. 9 90 161. I 162. 0 157.6 98.0 119.
46 88.3 88. 2 84.3 5(). 6 63. 3 9] 162.6 163. 6 159. 2 99. () 12(). 3
47 90. 1 90.0 86. 0 51. 7 64. 6 92 164. 2 165. 2 160.8 100. 1 12]. 6
48 91.9 91.8 87.7 52.8 65.9 93 165. 7 | 166. 7 | 162. 4 || 101. I 122.8
49 93. 6 93. 6 89.5 53.9 67. 2 94 167.3 | 168. 3 | 164. 0 || 102.2 124. ()
50 95.4 95.4 91. 2 55. 0 68. 5 95 168.8 169.9 165. 6 103.2 125. 2
51 97. 1 97. 1 92.9 56. 1 69.8 96 | 70.3 171.5 167.2 104.2 126. 5
52 98.8 98.9 94.6 57. I 71. 1 97 171.9 || 173. 1 || 168. 8 || 105.3 127. 7
53 100. 6 100. 6 96.3 58. 2 72. 4 98 173.4 174, 6 170. 4 106. 3 128.9
54 102. 2 102.3 98.0 59. 3 73. 7 99 175. 0 || 176. 2 || 172. 0 || 107.4 130.2
55 104. 0 104. 1 99.7 60. 3 74. 9 100 176. 5 177.8 173. 6 108.4 131. 4
B. DETERMINATION OF MANNOSE, ARABINOSE, SORBOSE, AND XY LOSE
Weight of copper corresponding to— Weight of copper corresponding to—
Milli- Milli- |_
grams of Arabi grams of Arabi
Sugar raol- || S * Sugar AT3DI-
Mannose In OSe Sorbose Xylose MannoSe In OS6) Sorbose | Xylose
mg Cu mg Cu mg Cu mg Cu qng Cu mg Cu mg Cu mg Cu
10 20. 7 21, 2 15. 20. 1 60 113. 3 119. 3 88.4 113. 2
20 40. 5 41.9 30. 5 39.6 70 130, 2 137.5 102.3 130.6
30 59.5 62. 0 45. 3 58. 7 80 146.9 155.3 115.9 147, 6
40 78. () 81. 5 59. 9 77.3 90 163. 3 172.7 129.4 164. 2
50 95.9 100. 6 74. 2 95.4 100 179.4 189. 8 142.8 180. 5


588
Circular of the National Bureau of Standards
TABLE 82.-Herzfeld table for determining invert sugar in raw sugars (invert sugar
not to eacceed 1.5 percent)



Invert Invert Invert Invert Invert
Copper Sugar Copper Sugar Copper Sugar Copper Sugar Copper Sugar
mg % 7mg % Tng % 7mg % 7ng %
50 || 0.050 105 || 0.325 160 || 0. 621 215 0.929 270 | 1. 242
51 . 054 106 | . 330 161 | . 627 216 | . 935 271 | 1, 248
52 . 058 107 . 335 162 . 633 217 . 940 272 | 1. 253
53 . 062 108 .340 163 . 639 218 .946 273 || 1, 259
54 | . 066 109 | . 346 164 | . 645 219 | . 951 274 1, 265
55 | . 070 110 ! .351 165 | . 651 220 | . 957 275 | 1. 271
56 .074 111 . 356 166 . 657 221 . 962 276 | 1.276
57 | . 078 112 | .361 167 . 663 222 | .968 277 | 1.282
58 . 082 113 . 366 168 . 669 223 . 973 278 1, 288
59 . 086 114 | . 371 169 | . 675 224 .979 279 | 1. 294
60 | . 090 115 | . 376 170 | . 680 225 | . 984 280 | 1.299
61 . 094 116 | . 381 171 . 686 226 . 990 281 | 1.305
62 . 098 117 . 386 172 . 692 227 . 996 282 | 1, 311
63 . 103 118 . 392 173 . 698 228 | 1.001 283 | 1.317
64 . 108 119 . 397 174 . 704 229 | 1.007 284 | 1.322
65 . 113 120 . 402 175 . 709 230 | 1.013 285 | 1.328
66 . 118 121 . 407 176 . 715 231 | 1.018 286 | 1.334
67 . 123 122 . 412 177 . 720 232 | 1.024 287 | 1.339
68 . 128 123 . 417 178 . 726 233 | 1.030 288 | 1.345
69 . 133 124 . 423 179 . 731 234 | 1.036 289 | 1.351
70 | . 138 125 | . 428 180 . 737 235 | 1.041 290 | 1.357
71 . 143 126 . 433 181 . 742 236 | 1. 047 291 | 1.362
72 . 148 127 . 438 182 . 748 237 | 1.053 292 | 1.368
73 | . 152 128 . 443 183 . 753 238 | 1.058 293 | 1.374
74 | . 157 129 | . 448 184 | . 759 239 | 1.064 294 | 1. 380
75 . 162 130 . 453 185 . 764 240 | 1.070 295 | 1.385
76 167 131 . 458 186 . 770 241 | 1.076 296 | 1.391
77 | . 172 132 | . 463 187 | . 775 242 | 1.081 297 | 1.397
78 . 177 133 . 468 188 . 781 243 | 1.087 298 || 1.403
79 . 182 134 . 473 I89 . 786 244 | 1.093 299 || 1.408
80 | . 187 135 | . 478 190 | . 792 245 | 1.099 300 | 1.414
81 . 192 136 . 483 191 ... 797 246 | 1. 104 301 | 1.420
82 . 197 137 . 488 192 . 803 247 | 1. 110 302 | 1.425
83 . 202 138 . 493 193 . 808 248 | 1. 116 303 | 1.431
84 . 208 139 . 498 194 ... 814 249 | 1. 122 304 || 1.437
85 . 213 140 . 503 I95 ... 819 250 | 1. 127 305 | 1.443
86 . 219 141 . 509 196 . 825 251 | 1. 133 306 | 1.448
87 . 225 142 . 515 197 . 830 252 | 1. 139 307 | 1.454
88 . 231 143 . 521 198 . 836 253 | 1. 144 308 || 1.460
89 . 236 144 . 527 199 . 841 254 | 1. 150 309 | 1.466
90 . 242 145 , 533 200 . 847 255 | 1. 156 310 | 1.471
91 . 248 146 . 538 201 . 852 256 | 1, 162 311 | 1.477
92 . 254 147 . 544 202 . 858 257 | 1. 167 312 | 1. 483
93 . 260 148 . 550 203 .863 258 | 1. 173 313 | 1. 489
94 . 265 149’| . 556 204 . 869 259 1. 179 314 | 1.494
315 | 1.500
95 . 271 150 . 562 205 . 874 260 | 1.185
96 . 277 151 . 568 206 . 880 261 | 1. 190
97 . 283 152 . 574 207 . 885 262 | 1. 196
98 . 288 153 . 580 208 . 891 263 | 1. 202
99 | . 294 154 . 586 209 | . 896 264 | 1. 207
100 | . 300 155 | . 592 210 | .902 265 | 1. 213
101 . 305 156 . 598 211 . 907 266 | 1. 219
102 . 310 157 . 604 212 913 267 | 1.225
103 | . 315 158 | . 609 213 | . 918 268 | 1. 231
104 . 320 159 . 615 214 . 924 269 | 1. 236
Polarimetry, Saccharimetry, and the Sugars 589
TABLE 83.−Determination of invert *... Vondrak's modification of the Herzfeld
7metho
[Add five roughened glass beads]
Sucrose (grams) Sucrose (grams)
Copper 10 2.5 0 Copper J() 2.5 ()
Invert Sugar Invert Sugar
mg mg Tng 7mg Tng 7ng 7ng Tng
5 -------------|------------- 2 80 28 35 43
10 -------------|------------- 5 85 30 38 45
15 -------------|------------- 8 90 33 41 48
20 ------------- 3 10 95 35 43 51
25 ||------------- 6 13 100 38 46 54
30 ||------------- 9 15 110 43 52 59
35 3 11 18 120 48 58 65
40 6 13 21 130 53 64 70
45 4) I6 24 140 59 70 76
50 12 I9 27 150 65 77 81
55 14 22 29 160 71 83 87
60 17 2. 32 170 78 89 92
65 20 27 35 180 84 95 98
70 23 30 37 190 90 -------------|------------
75 25 33 40 200 96 ||-------------------------

TABLE 84.—Meissl and Hiller factors for invert sugar'

[Where more than 1.5% is invert sugar and less than 98.5% is sucrose]
- º Approximate absolute weight of invert sugar (Z)
Ratio of sucrose to invert
Sugar= R:I
200 mg 175 mg 150 mg 125 mg 100 mg 75 mg 50 mg
0.100-------------------------- 56.4 55.4 54.5 53.8 53.2 53.0 53.0
10:90--------------------------- 56.3 55. 3 54.4 53.8 53.2 52.9 52.9
20:80--------------------------- 56.2 55.2 54.3 53.7 53.2 52.7 52.7
30:70--------------------------- 56. 1 55. 1 54.2 53.7 53.2 52, 6 5.2. 6
40:60--------------------------- 55.9 55. 0 54. 1 53. 6 53. 1 52.5 52.4
50:50--------------------------- 55. 7 54.9 54.0 53.5 53. 1 52. 3 52.2
60:40--------------------------- 55, 6 54. 7 53.8 53.2 52.8 52. 1 51.9
70:30--------------------------- 55. 5 54.5 53.5 52.9 52.5 51.9 51.6
80:20--------------------------. 55.4 54. 3 53.3 52.7 52.2 51. 7 51.3
90:10--------------------------- 54.6 53. 6 53. 1 5.2. 6 52. 1 51. 6 51.2
91.9---------------------------- 54. 1 53. 6 52.6 52. 1 51.6 51.2 50.7
92.8---------------------------- 53. 6 53. I 52. 1 51.6 51.2 50. 7 50.3
937---------------------------- 53. 6 53. 1 52. 1 51.2 50. 7 50.3 49.8
94:6---------------------------- 53. 1 52, 6 51. 6 50. 7 50.3 49.8 48.9
95:5---------------------------- 52.6 52. 1 51.2 50.3 49.4 48.9 48, 5
96-4---------------------------- 52. I 51.2 50.7 49.8 48.9 47.7 46.9
97.3---------------------------- 50. 7 50.3 49.8 48.9 47. 7 46.2 45. 1
982---------------------------- 49.9 48.9 48.5 47.3 45.8 43.3 40.0
991---------------------------- 47. 7 47. 3 46, 5 45. 1 43.3 41.2 38. 1
1 Z. Ver. Rübenzucker-Ind. 39 [N. F. 26) 734 (1889).
323414°–42—39
590 Circular of the National Bureau of Standards
TABLE 85.-Factors for 10 ml of Sozhlet solution to be used in connection with the
Lane and Eynon general volumetric method
$– q; *- cl *- CD “…- q, “- vo • - v. -- ~ 2: C
§3 || 3 || 3 || 3 || 3 || 3 || 3 || 3.2 : # 3 || | | | | | | | }.
ż, ###| g =#| ###| ### #3; #35 | #35 | #3;
º (a twº CAE; - - U2 ce sº O cº
.#~ || 3: 35 | #3; £3; # # ºi:3 |EEE j . E.g.
* | ###| * : * | * g : ºf £ ºg # | 5 || 5 || 2 sº || 2:3 || 2: ... . . . ;
3 | #33 || 803.5 tº 3.5 | * = a | * * = | : # = EC | *EC= | Eið | *:5
:- || -- *- Aft s § ſº H -: - -r: -
ml
15 50. 5, 49. 9| 47. 6| 46. 1 || 43. 4| 49. 1, 52. 2 77. 2 81. 3| 64. 9| 68. 3
16 50. 6, 50.0|| 47. 6|| 46. 1 || 43. 4| 49. 2. 52. 3| 77. 1 || 81.2| 64, 8, 68. 2
17 | 50. 7| 50. 1, 47. 6| 46. 1| 43. 4| 49. 3. 52. 3| 77. 0 81. 1| 64, 8, 68. 2
18 50. 8 50. 1, 47. 6| 46. 1 || 43. 3| 49. 3. 52. 4 77. 0 81. 0 64. 7| 68. 1
19 || 50. 8 50. 2 47. 6| 46. 1| 43. 3. 49.4 52. 5, 76.9| 80. 9| 64. 7| 68. 1
20 50. 9, 50. 2 47. 6, 46. 1| 43. 2 49. 5| 52. 5| 76. 8 80. 8| 64. 6 68. ()
21 || 51.0 50. 2 47. 6| 46. 1 || 43. 2 49.5 52. 6| 76. 7 80. 7| 64. 6 68. ()
22 || 51.0 50. 3| 47. 6, 46. 1 || 43. 1 || 49.6 52. 7| 76. 6, 80. 6| 64. 6 68. ()
23 51. 1 50. 3| 47. 6, 46. 1 || 43. O 49. 7| 52. 7| 76. 5 80. 5 64. 5| 67. 9
24 || 51. 2 50. 3| 47. 6, 46. 1 || 42. 9| 49. 8| 52. 8| 76. 4| 80. 4| 64. 5 6.7. 9
25 || 51. 2 50. 4, 47. 6, 46. 0| 42.8 49.8 52. 8 76.4 80. 4, 64. 5 6.7. 9
26 || 51. 3. 50. 4, 47. 6|| 46. O 42. 8 49. 9| 52.9| 76. 3| 80. 3| 64. 5| 67. 9
27 | 51. 4 50. 4, 47. 6, 46. O 42. 7| 49. 9| 52.9| 76. 2 80. 2 64. 4, 67. 8
28 || 51.4 50. 5 47. 7| 46. O 42. 7| 50.0 53. 0 76. 1 80. 1 || 64. 4| 67. 8
29 || 51. 5 50. 5 47. 7| 46. O 42. 6, 50. 0| 53. 1| 76. 0 80. 0 64. 4 67. 8
30 || 51. 5 50. 5, 47. 7| 46. O 42. 5 50. 1| 53. 2 76. 0 80. 0 64. 4 67. 8
31 || 51. 6|| 50. 6 47. 7| 45.9| 42. 5 50. 2 53. 2 75. 9 79.9| 64. 4 67. 8
32 || 51. 6| 50. 6, 47. 7| 45.9| 42. 4 50. 2 53. 3| 75. 9 79.9| 64. 4 67. 8
33 || 51. 7| 50. 6| 47. 7| 45.9| 42. 3. 50. 3| 53. 3| 75. 8| 79. 8| 64. 4 67. 8
34 || 51. 7| 50. 6|| 47. 7| 45.8 42. 2 50. 3. 53. 4| 75. 8 79. 8| 64. 4| 67. 9
35 | 51. 8 50. 7| 47. 7| 45. 8 42. 2, 50. 4, 53. 4| 75. 7| 79. 7| 64. 5| 67. 9
36 51. 8: 50. 7 47. 7| 45. 8| 42. 1 50. 4, 53. 5. 75. 6| 79. 6| 64. 5| 67. 9
37 || 51. 9, 50. 7| 47. 7| 45. 7| 42. O 50. 5| 53. 5. 75. 6| 79. 6| 64. 5, 67. 9
38 || 51. 9, 50. 7| 47. 7 45. 7| 42. O 50. 5 53. 6|| 75. 5. 79. 5, 64. 5 6.7. 9
39 52. 0 50. 8 47. 7| 45. 7 41. 9, 50. 6. 53. 6|| 75. 5. 79. 5 64. 5 67. 9
40 52. 0| 50. 8| 47. 7| 45. 6 41.8 50. 6. 53. 6| 75. 4| 79.4| 64. 5| 67. 9
41 52. 1| 50. 8 47. 7| 45. 6 41.8 50. 7| 53. 7| 75. 4| 79.4| 64. 6 68. 0
42 52. 1 50. 8| 47. 7| 45. 6 41. 7 50. 7| 53. 7| 75. 3| 79. 3| 64. 6 68. ()
43 52. 2 50. 8 47. 7| 45. 5 41. 6 50. 8 53. 8| 75. 3| 79. 3| 64. 6| 68. 0
44 52. 2 50. 9 47. 7| 45. 5 4 1. 5 50. 8, 53. 8| 75. 2 79. 2 64. 6 68. 0
45 52. 3. 50. 9| 47. 7 45. 4. 41. 4| 50. 9, 53. 9 75. 2 79. 2 64. 7| 68. 1
46 52. 3. 50.9| 47. 7, 45. 4. 41.4 50. 9 53. 9 75. 1 79. 1| 64. 7| 68. 1
47 52.4 50. 9, 47.7 45. 3, 41. 3 51.0 53.9 75. 1 79. 1| 64.8 68.2
48 52. 4 50. 9| 47. 7 45. 3, 41. 2 51. O 54. 0 75. 1 79. 1| 64. 8| 68. 2
49 || 52. 5|| 51. 0| 47. 7 * * 4.1. 1 || 51. 0 54. 0| 75. O| 79. 0 64. 8, 68. 2
50 52.5 51.0, 47.7 45.2 1 0 31, 1 34.0. 75.0. 79 0 64.9 as 3
Polarimetry, Saccharimetry, and the Sugars
591
TABLE 86.-Factors for 25 ml of Sozhlet solution to be used in connection with the
Lane and Eynon general volumetric method

->
2, 3 3- 3: # = #3 =T.
... } #. º d) 35 £3. É: gº
# 43 =#| | . s £3 #: É #5
ā- }-4 y-4 2. .* •r. ;I, -r: º
7nl
15 123. 6 122. 6 | 120. 2 | 127. 4 197. 8 208. 2 163. 9 172. 5
16 123. 6 122. 7 || 120. 2 | 127. 4 197. 4 207. 8 163, 5 172. 1
17 123. 6 122. 7 || 120. 2 | 127. 5 197. () 207. 4 163. 1 171. 7
18 123. 7 122. 7 | 120. 2 | 127. 5 196. 7 207. I 162. 8 171. 4
19 123. 7 122. 8 || 120. 3 || 127. 6 196. 5 206. 8 262. 5 171. 1
20 123. 8 122. 8 || 120. 3 | 127. 6 196. 2 206. 5 162. 3 170. 9
21 123. 8 122. 8 120. 3 || 127. 7 195. S 206. I 162. 0 170. 6
22 123, 9 122, 9 || 120. 4 || 127. 7 195. 5 205. 8 16.1. 8 170. 4
23 123, 9 122. 9 || 120. 4 127. 8 195. 1 205. 4 161. 6 170. 2
24 124, () 122. 9 || 120, 5 || 127. 8 194, 8 205. 1 161. 5 170. ()
25 124. () 123. 0 | 120. 5 | 127. 9 194, 5 204, 8 161. 4 169. 9
26 124, 1 123. 0 | 120. 6 127. 9 194, 2 204. 4 161. 2 169. 7
27 124. 1 123. 0 | 120. 6 | 128. () 193, 9 204. 1 161. 0 169. 5
28 124, 2 123. 1 120. 7 | 128. 0 193, 6 203. 8 160. 8 169. 3
29 124. 2 123. 1 120. 7 || 128. 1 193, 3 203. 5 160. 7 169. 2
30 124. 3 123. 1 120. 8 || 128. 1 193. () 203. 2 160. 6 169. 0
31 124. 3 123. 2 | 120. 8 128. 1 192. 8 202. 9 160. 5 168. 9
32 124. 4 123. 2 | 120. 8 128. 2 192. 5 202. 6 160. 4 168. 8
33 124. 4 123. 2 | 120. 9 || 128. 2 192. 2 202. 3 160. 2 168. 6
34 124. 5 123. 3 | 120. 9 || 128. 3 191. 9 202. () 160. 1 168. 5
35 124. 5 123. 3 | 121. 0 | 128. 3 191. 7 201. 8 160. 0 168. 4
36 124, 6 123. 3 | 121. 0 | 128. 4 191. 4 201. 5 159. 8 168. 2
37 124. 6 123. 4 || 121. 1 | 128. 4 191. 2 201. 2 159. 7 168. 1
38 124. 7 123. 4 || 121. 2 | 128. 5 191. 0 201. 0 159. 6 168. 0
39 124, 7 123. 4 || 121. 2 | 128. 5 190. 8 200. 8 169. 5 167. 9
40 124. 8 123. 4 || 121. 2 | 128. 6 190. 5 200. 5 159. 4 167. 8
41 124, 8 123. 5 | 121. 3 | 128. 6 190. 3 200. 3 159. 3 167. 7
42 124. 9 123. 5 | 121. 4 || 128. 6 190. I 200. 1 159. 2 167. 6
43 124. 9 123. 5 | 121. 4 || 128. 7 189. 8 199. 8 159. 2 167. 6
44 125. 0 123. 6 121. 5 | 128. 7 189. 6 199. 6 159. 1 167. 5
45 125. 0 123. 6 | 12:1. 5 | 128. 8 189. 4 199. 4 159. 0 167. 4
46 125. 1 123. 6 | 121. 6 | 128. 8 189. 2 199. 2 159. 0 167. 4
47 125. 1 123. 7 | 121. 6 128. 9 189. 0 199. 0 158. 9 167. 3
48 125. 2 123. 7 | 121. 7 | 128. 9 188. 9 198. 9 158. 8 167. 2
49 125. 2 123. 7 | 121. 7 || 129. 0 188. 8 198. 7 158. 8 167. 2
50 125. 3 123. 8 || 12.1. 8 || 129. 0 188. 7 198. 6 158. 7 167. 1
592 Circular of the National Bureau of Standards
TABLE 87.—Burette readings for solutions containing 25 g of sugar sample plus
0.1 g of added invert sugar per 100 ml

[10 ml of Fehling solution used]
* Invert Sugar & Invert Sugar
; “inº" || j “inº
sample sample
Tml Percent 'ml Percent
20 0.464 32 0. 128
21 . 423 33 . 111
22 . 384 34 . 095
23 . 348 35 . 080
24 . 315 36 . 066
25 . 284 37 . 052
26 . 257 38 . 040
27 . 232 39 . 028
28 . 209 40 . 017
29 . 188 41 . 008
30 . 168 41, 7 . 000
31 . 148 || - - - - - - - - - - - - - - - - - -
Polarimetry, Saccharimetry, and the Sugars
593
TABLE 88.-Corrections, in milliliters, to be added to burette readings in the titration
of lactose solutions containing three or six times as much sucrose as lactose

10 ml of Fehling 25 ml of Fehling
solution solution
Sugar
Solution Ratio of Sucrose to Ratio of sucrose
required 3CUOSę to lactose
3:1 6:1 3:1 6:1
7ml 7ml 7ml 7ml ml
15 0.15 0.30 0.30 0.60
20 . 25 . 50 . 30 . 60
25 . 30 . 60 . 35 . 65
30 . 35 . 70 . 35 . 70
35 . 40 . 80 . 40 . 80
40 .45 . 90 .45 .90
45 . 50 . 95 55 1. 10
50 . 55 1.05 . 60 1. 20
594 Circular of the National Bureau of Standards
TABLE 89.—Factors for the Lane and Eynon volumetric method for mixtures of
deatrose and levulose
The factor represents the number of miligrams of sugar required to reduce 25
ml of Soxhlet reagent.
100xº-mg of sugar in 100 ml.
titer
| ;
T; # or IYov fro- 90 D 80 D 70 D 60 D 50 ID | 40 ID
Titer Dextrose ſº, i. 20 L 30 L 40 l. 50 I, 60 L
ml
15 120. 2 120. 9 121. 6 122.2 122. 9 123. 6 124. 4
16 120. 2 120. 9 121. 6 122. 2 122. 9 123. 6 124. 4
17 120. 2 | 20. 9 121. 6 | 22. 2 122. 9 123. 6 124. 4
18 120. 2 120. 9 121. 6 122. 3 123. 0 123. 7 124. 5
19 120. 3 | 21. () 121. 7 122. 3 123. 0 123. 7 124. 5
20 120. 3 121. () 121. 7 122. 4 123. 1 | 23. 8 124. 6
21 120. 3 121. 0 121. 7 122. 4 123. 1 123. 8 | 24, 6
22 120. 4 121. I 121. 8 122. 5 123. 2 123. 9 124. 7
23 120. 4 121. I 121. 8 122. 5 123. 2 123. 9 | 24, 7
24 | 20. 5 121. 2 121. 9 122. 6 123. 3 124. 0 124. 8
25 120. 5 121. 2 121. 9 122. 6 123. 3 124. 0 124. 8
26 | 20. 6 121. 3 122. () 122. 7 123.4 124. 1 124. 9
27 120. 6 | 21. 3 122. 0 122. 7 123. 4. 124. 1 124. 9
28 120. 7 121. 4 122. 1 122. 8 123. 5 | 24. 2 125. 0
29 120. 7 121. 4 122. 1 122. 8 123. 5 124, 2 125. 0
30 120. 8 121. 5 122. 2 122. 9 123. 6 124. 3 125. 1
31 120. 8 | 21. 5 | 22. 2 122. 9 123. 6 124, 3 125. I
32 | 20. 8 121. 5 122. 2 123. 0 123. 7 124. 4 125, 2
33 | 20. 9 121. 6 122. 3 123. 0 123. 7 124. 4 125. 2
34 120. 9 121. 6 122. 3 123. 1 123. 8 124. 5 125. 3
35 121. 0 121. 7 1 22.4 123. 1 123. 8 124. 5 125. 3
36 | 21. 0 121. 7 122.4 123. 2 123. 9 124. 6 125. 4
37 121. I 121. 8 122. 5 123. 2 123. 9 124. 6 125. 4
38 121. 2 121. 9 122. 6 123. 3 124. 0 124. 7 125. 5
39 121. 2 121. 9 122. 6 123. 3 124. 0 i24, 7 125. 5
40 121. 2 121. 9 122. 6 123. 4 124. 1 124. 8 125. 6
41 121. 3 122. 0 122. 7 123. 4 124. 1 124. 8 125. 6
42 12]. 4 122. 1 122. 8 123. 5 124. 2 124. 9 125. 6
43 121. 4 122. 1 122. 8 123. 5 124, 2 124. 9 125. 7
44 121. 5 122. 2 122. 9 123. 6 124.3 125. 0 125. 7
45 121. 5 122. 2 122. 9 123. 6 124. 3 125. 0 125. 8
46 121. 6 122. 3 123. 0 123. 7 124. 4 125. 1 125. 8
47 121. 6 122. 3 123. 0 123. 7 124. 4 125. 1 125. 9
48 121. 7 122. 4 123. 1 123. 8 124. 5 125. 2 125. 9
49 121. 7 122.4 123. 1 123. 8 124. 5 125. 2 126. 0
50 121. 8 122. 5 123. 2 123. 9 124. 6 125. 3 126. 0
Polarimetry, Saccharimetry, and the Sugars 595
TABLE 89.-Factors for the Lane and Eynon volumetric method for mixtures of
dea:trose and levulose—Continued
In the last three columns are titer corrections corresponding to experimentally
determined factors which differ from the tabulated factors by 1, 2, and 3 units.
When the experimental factor is greater than the tabulated, the correction is to
be subtracted from the observed titer, and vice versa. This corrected titer is to
be used with the tabulated factor.
D D D Titer corrections
* * 30 20 10
Titer 70 L 80 L 90 I, Levulose
1 2 3
ml ml ml ml
15 125. 1 125. 9 126. 6 127. 4 0. 12 0. 24 0. 37
16 125. 1 125. 9 126. 6 127. 4 13 . 26 39
17 125. 2 125. 9 126. 7 127. 5 14 . 28 41
18 125. 2 126. 0 126. 7 127. 5 15 . 30 44
19 125. 3 126. 0 126. 8 127. 6 15 . 31 46
20 125. 3 126. 1 126. 8 127. 6 16 . 33 49
21 125. 4 126. 1 126. 9 127. 7 17 . 34 51
22 125. 4 126. 2 126. 9 127. 7 18 . 36 54
23 125. 5 126. 2 127. 0 127. 8 19 . 37 56
24 125. 5 126. 3 127. 0 127. 8 20 . 39 59
25 125. 6 126. 3 127. 1 127. 9 20 . 41 61
26 125. 6 126. 4 127. 1 127. 9 21 . 42 63
27 125. 7 126. 4 127. 2 128. 0 22 44 66
28 125. 7 126. 5 127. 2 128. 0 23 . 45 68
29 125. 8 126. 5 127. 3 128. 1 24 . 47 71
30 125. 8 126. 6 127. 3 128. 1 25 49 73
31 125. 8 126. 6 127. 3 128. 1 25 . 50 76
32 125. 9 126. 7 127. 4 128. 2 26 52 78
33 125. 9 126. 7 127. 4 128. 2 27 54 80
34 126. 0 126. 8 127. 5 128. 3 28 55 83
35 126. 0 126. 8 127. 5 128. 3 29 57 85
36 126. 1 126. 9 127. 6 128. 4 29 59 88
37 126. 1 126. 9 127. 6 128. 4 3 . 60 90
38 126. 2 127. 0 127. 7 128. 5 31 . 62 93
39 126. 2 127. 0 127. 7 128. 5 32 . 63 95
40 126. 3 127. 1 127. 8 128. 6 33 . 65 . 98
41 126. 3 127. 1 127. 8 128. 6 33 . 67 1. 00
42 126. 4 127. 1 127. 9 128. 6 34 . 68 1. 02
43 126. 4 127. 2 127. 9 128. 7 35 . 70 1. 05
44 126. 5 127. 2 128. 0 128. 7 36 . 72 1. 07
45 126. 5 127. 3 128. 0 128. 8 37 . 73 1. 10
46 126. 6 127. 3 128. 1 128. 8 37 . 75 1. 12
47 126. 6 127. 4 128. 1 128. 9 38 . 76 1. 15
48 126. 7 127. 4 128. 2 128. 9 39 . 78 1. 17
49 126. 7 127. 5 128. 2 129. 0 40 . 80 1. 20
50 126. 8 127. 5 128. 3 129. 0 41 81 1. 22
596
Circular of the National Bureau of Standards
TABLE 90.-Zerban and Wiley factors for mixtures of deatrose and levulose (Lane
and Eymon method)
[10 ml of Soxhlet solution]

Titer | 100 D | 90 D | 80 D | 70 D ||60 D 50 D | 40 D | 30 D 20 D | 10 D | 0 D
0 L | 10 L | 20 L 30 L | 40 L | 50 L | 60 L | 70 L | 80 L | 90 L | 100 L
IN THE PRESENCE OF 10 G OF SUCROSE IN 100 ML
15 46. 1| 46. 3| 46. 5 46. 6, 46.8 47.0 47. 2 47. 4. 47. 7| 47.9 48. 1
20 45.8 46.0 46. 2 46. 3| 46. 5 46.7| 46.9| 47. 1| 47.3 4.7. 5 47. 7
25 45. 5 45. 7| 45.8 45.9 46. 1| 46. 3| 46. 5| 46.7| 46.9| 47. 1, 47.3
30 45. 2 45. 4 45. 5| 45. 7| 45.8 46.0 46. 2 46.4| 46.5, 46. 7| 46.9
35 45. O 45. 1, 45. 3| 45. 4 45. 6| 45. 7| 45.9 46. 1 46. 2 46.4. 46.6
40 44. 9| 45.0| 45. 2 45. 3| 45. 5 45.6| 45. 8| 45.9 46. 1| 46. 3| 46.4
45 44. 8] 44. 9| 45. 1| 45. 2 45.4| 45. 5 45.6 45.8 45.9 46. 1| 46.2
50 44. 7| 44.8 45.0 45. 1, 45.3| 45. 4 45. 5| 45. 7| 45.8 46.0 46. 1
IN THE PRESENCE OF 25 G OF SUCROSE IN 100 ML
15 42.9| 43. 1| 43. 2 43. 4. 43. 6| 43. 7| 43.9| 44. 1ſ 44.3| 44. 5 44. 7
20 42. 6| 42. 7| 42.9| 43. 0| 43. 1. 43. 2 43. 4| 43. 5. 43. 7| 43.8 44. 0
25 42. 3| 42. 4 42. 5 42. 6 42. 7| 42.8 42.9| 43. 1ſ 43. 2, 43. 4| 43. 5
30 42. 0| 42. 1| 42. 2 42. 3| 42. 4| 42. 5 42. 6| 42. 7| 42.8| 42.9| 43.0
35 41. 6|| 41. 7| 41.8 41.9| 42.0. 42. 1| 42. 2 42. 3| 42. 4 42. 5 42. 6
40 41. 3| 41. 4| 41. 5. 41. 6|| 41. 7| 4.1. 8| 41.9 42.0| 42. 1| 42. 2 42. 3
45 40. 9| 41.0|| 41. 1. 41. 2 41. 3| 41. 4. 41. 5. 41. 6 41. 7| 4.1. 8 41.9
50 40. 5 40. 6| 40. 7| 40. 8 40.9| 41.0|| 41. 1| 41.2| 41. 3| 41. 4. 41. 5
TABLE 91.-Lane and Eynon factors and reducing ratios for
dea:trose and levulose in raw sugars
[10-ml of Soxhlet solution]
determinimation of
10 grams of sucrose 25 grams of sucrose
º Reduc- º Reduc-
Titer E ing a — 0.0806 Titer E ing a — 0.0806
ynon º ynOn &
factor ratio, a factor ratio, a
ml ml
15 48. 1 | 1. 0434 0. 96.28 15 44. 7 | 1. 0419 0.9613
20 47. 7 | 1. 0414 . 9608 20 44. 0 | 1. 0324 . 9518
25 47. 3 | 1.0394 . 9588 25 43. 5 | 1. 0273 . 94.67
30 46. 9 | 1. 0374 . 9568 30 43. 0 | 1. 0248 . 94.42
35 46. 6 1, 0354 . 9548 35 42. 6 | 1. 0246 . 9440
40 46.4 1, 0334 . 9528 40 42. 3 | 1. 0245 . 9439
45 46. 2 | 1. 0314 . 95.08 45 41. 9 | 1. 0244 . 9438
50 46. 1 | 1. 0311 . 9505 50 41. 5 | 1. 0234 . 9437
Polarimetry, Saccharimetry, and the Sugars
597
TABLE 92.—Milligrams of deactrose and levulose corresponding to milligrams of
cupric oxide or copper, and reduction ratio, a, according to Erb and Zerban, for
various proportions of deactrose and levulose in the presence of sucrose (0.4 g of total
sugar in 50 ml of solution), using the Munson and Walker method
Reduction ratio, a, for varying proportions between D and L

Cupric] Cop- || Levu- || Dex- 100 D | 90 D | 80 D | 70 D 50 D | 40 D | 30 D | 20 D | 10 D
Oxide per lose troSe | 0 L 10 L | 20 L | 30 L 50 L | 60 L | 70 L | 80 L | 90 L
Tng Tng Tng -
50 39.9 18. 3 16. 3 | 1. 119 | 1. 121 | 1. 123 | 1. 125 1. 129 | 1. 127 | 1.126 | 1.125 1. 124
75 59.9 29, 2 26. 2 | 1. 115 | 1. 118 | 1. 120 | 1.123 1. 127 | 1.126 | 1. 125 | 1.125 1. 124
100 79.9 40.2 36.2 | 1. 111 | 1. 114 | 1. 117 | 1. 120 1, 125 | 1. 125 | 1. 125 | 1. 125 1. 124
125 99.9 51.3 46, 3 | 1. 108 || 1. 111 | 1. 114 | 1. 117 | 1. 120 | 1, 123 | 1. 123 | 1. 123 | 1. 124 1. 124
150 | 119.8 62. 5 56.6 | 1. 105 | 1. 108 | 1. 111 | 1. 114 1. 119 | 1. 120 | 1. 121 | 1. 122 1. 124
175 | 139.8 73. 8 67.0 | 1. 101 | 1. 104 | 1. 107 | 1. 110 1. 114 | 1. 116 | 1. 117 | 1. 118 1. 119
200 | 159.8 85. 1 77. 5 | 1.098 || 1. 101 | 1. 103 | 1. 106 1. 110 | 1. 111 | 1. 112 | 1. 113 1. 114
225 || 179. 8 || 96.5 | 88. 0 | 1.096 || 1.097 | 1.099 1. 101 1. 105 | 1. 106 | 1. 107 | 1. 108 || 1. 108
250 | 199. 7 || 108. 0 || 98.8 1.093 | 1.095 | 1.097 | 1.098 1. 100 | 1. 101 | 1. 102 | 1. 103 | 1. 103
275 219, 7 || 119.6 || 109.8 | 1.089 | 1.091 | 1.093 | 1,093 1.095 | 1.096 | 1.096 || 1,097 | 1,096
300 || 239. 7 || 131. 2 | 120.8 | 1.086 | 1.087 | 1.088 | 1.089 1.091 | 1.091 | 1.090 | 1.090 | 1. 090
325 259, 6 || 142.9 || 131.8 | 1.084 || 1.085 | 1,086 | 1.086 º 1.086 | 1.086 | 1.086 | 1.085 1.085
350 279, 6 || 154.8 || 143. 2 | 1.081 | 1.081 | 1.082 | 1.082 | 1.082 | 1.082 | 1. 082 | 1.082 | 1.081 | 1.081
375 299. 6 || 166. 7 || 154. 5 | 1.079 | 1.079 | 1.078 | 1.078 1.077 | 1.077 | 1.077 | 1.077 | 1.077
400 319. 6 || 178.6 | 165.8 | 1.077 | 1.077 | 1.076 | 1.075 1.073 || 1.073 || 1.073 | 1.072 | 1.072
425 || 339. 5 | 190.6 || 177. 5 | 1.074 | 1.073 | 1.071 | 1. 070 1. 068 | 1.068 || 1. 068 || 1,068 1, 068
450 || 359, 5 || 202.8 189. 2 | 1.072 | 1,070 | 1. 069 || 1.067 1. 064 | 1.064 | 1.064 | 1.063 1. 063
475 || 379. 5 || 215. 0 || 200. 9 || 1. 0.70 | 1.067 | 1.065 | 1.063 1. 059 | 1.059 | 1.058 || 1.057 1.057
500 || 399.5 227. 1 212. 8 || 1.067 | 1.064 | 1.061 | 1.059 1.055 | 1.054 | 1.053 | 1.052 1. 052
525 || 419.4 || 239.4 224.8 | 1.065 | 1.062 | 1,059 | 1.056 1.050 | 1.050 | 1.050 | 1,049 1.049
550 || 439.4 || 251.9 || 237. 1 | 1.062 | 1.059 | 1.055 | 1,032 1.046 | 1.046 | 1.046 | 1.046 1.046
TABLE 93.-Copper-levulose
modification of the Nyms selective method for levulose
equivalents according to the Jackson and Mathews
‘t Levu- Levu- Levu- Levu- Levu-
Cu lose Cu lose Cu lose Cu lose Cu lose
frºg Tng Tng ng Trºg 7ng ng mg ng ºng
1 0, 6 20 7. 9 39 13. 7 58 || 19. 1 77 || 24. 5
2 1. 1 21 8. 2 40 | 13. 9 59 | 19. 4 78 24. 8
3 1. 6 22 8. 5 41 || 14, 2 60 | 19. 7 79 || 25. 1
4 2. 1 23 8. 9 42 14.5 61 | 20. 0 80 || 25. 4
5 2. 5 24 9. 2 43 || 14.8 62 | 20, 3 81 25. 7
6 2. 9 25 9. 5 44 | 15. 1 63 | 20. 6 82 25. 9
7 3. 3 26 9. 8 45 15.4 64 20. 9 83 26. 2
8 3. 7 27 | 10. 1 46 | 15. 7 65 | 21. 2 84 26. 5
9 4. 1 28 || 10. 4 47 | 16. 0 66 || 21. 4 85 26. 8
10 4. 5 29 || 10. 7 48 || 16. 3 67 21. 7 86 27. 0
11 4. 8 30 | 11. 0 49 | 16. 6 68 22. 0 87 27. 3
12 5. 1 31 11. 3 50 | 16. 8 69 22. 2 88 27. 6
13 5. 5 32 || 11. 6 51 17. 1 70 22. 5 89 || 27. 9
14 5. 9 33 || 11. 9 52 17. 4 71 22. 8 90 28. 1
15 6. 2 34 12. 2 53 17. 7 72 || 23. 1 91 28. 4
16 6. 5 35 | 12. 5 54 | 18. 0 73 || 23. 4 92 || 28. 7
17 6. 9 36 | 12. 8 55 | 18. 3 74 || 23. 7 93 || 29. 0
18 7. 2 37 || 13. 1 56 | 18. 6 75 24. 0 94 || 29. 2
19 7. 6 38 || 13. 4 57 18, 9 76 || 24. 2 95 || 29. 5
598 Circular of the National Bureau of Standards
TABLE 93.-Copper-levulose equivalents according to the Jackson and Mathews
modification of the Nyms selective method for levulose—Continued
Levu- Levu- Levu- Levu- Levu-
Cu lose Cu lose Cu lose Cu lose Cu lose
- - -- |
mg ng Tng mg *ng Tng mg *ng i ng mg
96 || 29. 8 140 || 42. 0 184 53. 6 238 || 65.3 || 272 79.7
97 || 30. 1 141 || 42. 3 185 53.9 229 | 66. 1 273 80. 0
98 || 30. 4 142 42. 6 186 54. 2 230 | 66. 4 274 80. 4
99 || 30. 7 143 || 42.8 187 54.4 231 | 66. 7 275 80. 7
100 30. 9 144 43. 1 188 54. 7 232 || 67. 0 276 81. 0
101 || 31. 2 145 || 43. 4 189 || 54. 9 233 || 67. 3 277 | 81. 4
102 || 3:1. 5 146 || 43. 7 190 || 55. 2 234 || 67. 6 278 81. 7
103 || 31. 8 147 || 43. 9 191 55. 5 235 | 67. 9 279 82. ()
104 || 32. 1 148 || 44, 2 192 || 55. 7 236 | 68. 2 280 | 82.4
105 || 32. 3 149 44. 5 193 56. 0 237 | 68. 5 281 82. 7
106 || 32. 6 150 || 44. 7 194 | 56. 3 238 | 68. 8 282 83. 1
107 || 32.9 151 || 45. 0 195 56. 5 239 69. 1 283 83. 4
108 || 33. 2 152 || 45. 3 196 || 56. 8 240 69. 4 284 || 83. 8
109 || 33. 5 153 || 45. 6 197 || 57. 1 241 69. 7 285 | 84. 1
110 || 33. 7 154 || 45.8 198 || 57. 3 242 70. 0 286 | 84.4
111 || 34. 0 155 46. 1 199 || 57. 6 243 || 70. 3 287 | 84. 8
112 || 34. 3 156 46. 4 200 || 57. 9 244 70. 7 288 85. 1
113 || 34. 6 157 || 46. 6 201 || 58, 1 245 || 71. 0 289 || 85. 5
114 || 34, 8 158 || 46. 9 202 || 58.4 246 || 71. 3 290 85. 9
115 35. 1 159 || 47. 1 203 || 58. 7 247 71. 6 291 86. 2
116 || 35. 4 160 47. 4 204 || 58.9 || 248 71.9 292 | 86. 6
117 | 35. 7 161 47. 7 205 || 59. 2 || 249 || 72. 2 293 86. 9
118 || 36. 0 || 162 || 47. 9 206 || 59. 4 250 | 72. 5 294 | 87. 3
119 || 36. 2 163 48. 2 207 || 59.7 || 251 | 72.8 295 || 87. 6
120 || 36. 5 164 || 48. 4 208 || 60. 0 || 252 | 73. 1 296 88. 0
121 || 36.8 165 || 48. 7 209 || 60. 3 253 | 73. 5 297 88.4
122 || 37. 1 166 49. 0 210 60. 6 254 | 73. 8 298 || 88. 7
123 37. 3 167 || 49. 2 211 60. 9 255 74. 1 299 || 89. 1
124 || 37. 6 168 || 49. 5 212 61. 1 256 || 74. 4 300 | 89. 5
125 || 37. 9 169 49. 7 213 61. 4 || 257 || 74. 7 301 | 89. 8
126 || 38. 2 170 50. 0 214 61. 7 258 75. 1 302 || 90. 2
127 | 38. 5 171 50. 2 215 62. 0 259 || 75. 4 303 || 90. 5
128 || 38. 7 172 50. 5 216 62. 3 260 || 75. 7 304 90. 9
129 || 39. () 173 || 50. 8 217 | 62. 6 261 || 76. 0 305 || 91... 3
130 || 39. 3 174 || 51. 0 218 62. 9 262 || 76. 4 306 || 91. 7
131 || 39. 6 175 || 51. 3 219 || 63. 2 263 || 76. 7 307 || 92. 0
132 || 39. 9 176 || 51. 5 220 | 63. 4 264 || 77. 0 308 || 92. 4
133 | 40. 1 177 || 51. 8 221 63. 7 265 || 77. 4 309 || 92.8
134 || 40. 4 178 || 52. 1 222 || 64. () 266 || 77. 7 310 | 93. 2
135 | 40. 7 179 || 52. 3 223 || 64. 3 267 || 78. 1 311 | 93. 5
136 | 40.9 || 180 52.6 224 || 64. 6 268 78. 4 312 || 93. 9
137 || 41. 2 || 181 || 52. 8 225 | 64. 9 269 || 78. 7
138 || 41. 5 182 53. 1 226 || 65. 2 270 79.0
139 || 41. 7 || 183 53. 4 227 65.5 271 79.4
| |
Polarimetry, Saccharimetry, and the Sugars 599
TABLE 94.—Ratio of levulose to total sugar from the Lane and Eymon titration and
Nyms “apparent” levulose
Example illustrating the use of table 94.—Assume that a solution of levulose
and dextrose gave a Lane and Eynon titer of 25.89 ml and that 20 ml of the same
solution precipitated 247.3 mg of copper by the modified Nyns method. The
original solution then contained by table 93 (100X 71.7)/20=358.5 mg of apparent
levulose per 100 ml.
* I'v TXl 25.89 × 358.5
Then 100 T 100 = 92.8.
Referring to the values tabulated below we find opposite this product and under
T= 25 the true ratio of levulose to total sugar to be 71.5 percent. The Lane and
Eynon factor is 125.7, and the total sugar per 100 ml is 125.7/25.89 = 485.5 mg, of
which 71.5 percent (347.1 mg) is levulose and 138.4 mg is dextrose.
º T= 15 T-25 | T = 35 | T = 45 # T= 15 | T = 25 | T-35 | T = 45
11 : 1. 2 | 1. 2 | 1. 1 | 1. 1 51 36. 5 || 36. 3 || 36. 1 || 35. 9
12 || 2. 1 2. 1 || 2, 0 || 2. 0 52 37. 3 || 37. 2 || 36. 9 || 36, 7
13 || 3. 0 || 3. 0 || 2. 9 2, 9 53 || 38. 2 | 38. 0 || 37. 8 || 37. 6
14 || 3. 9 3. 8 || 3. 8 || 3. 7 54 || 39. 1 || 38. 9 || 38. 6 || 38.4
15 4. 8 4. 7 || 4, 7 || 4. 6 55 || 39. 9 || 39, 7 || 39, 5 || 39. 3
16 || 5. 7 || 5. 6 || 5. 6 || 5. 5 56 | 40. 8 || 40. 6 | 40. 3 | 40. 1
17 | 6. 5 || 6. 5 || 6. 4 || 6.4 57 || 41. 7 || 41. 5 || 41. 2 | 40. 9
18 || 7. 4 || 7. 4 || 7. 3 || 7. 3 58 || 42. 5 || 42. 3 || 42. 1 || 41. 8
19 || 8. 3 || 8. 2 | 8. 2 | 8. 1 59 43. 4 || 43. 2 42. 9 || 42. 6
20 9. 2 9. 1 || 9. 1 || 9. 0 60 44. 2 || 44. 0 || 43. 8 || 43. 5
21 | 10. 1 || 10. 0 || 10. 0 || 9. 9 61 || 45. 0 || 44.8 44. 6 || 44, 3
22 || 11. 0 || 10. 9 || 10. 9 || 10. 8 62 || 45. 9 || 45. 7 || 45. 5 || 45. 2
23 11. 9 || 11. 8 || 11. 8 || 11. 7 63 || 46. 7 || 46. 5 46. 3 || 46. 0
24 | 12. 8 || 12. 7 | 1.2. 6 | 12. 5 64 || 47. 6 47. 4 || 47. 2 46. 9
25 | 13. 7 || 13. 6 || 13. 5 || 13. 4 65 || 48. 4 || 48. 2 || 48. 0 || 47. 7
26 || 14. 5 || 14. 4 || 14. 3 || 14. 2 66 || 49. 3 || 49. 0 || 48. 8 || 48. 5
27 | 15. 4 || 15. 3 || 15. 2 | 15. 1 67 || 50. 1 || 49. 9 || 49. 7 || 49. 4
28 || 16. 3 | 16. 2 | 16. 1 | 16. 0 68 || 51. 0 || 50. 8 || 50. 6 || 50. 2
29 17. 2 17. 1 || 17. 0 | 16. 9 69 || 51. 8 || 51. 6 || 51. 4 || 51. 1
30 | 18. 1 | 18. 0 || 17. 9 || 17. 8 70 52. 7 || 52. 5 52. 2 || 51. 9
3] | 19. 0 | 18. 9 || 18. 7 | 18. 6 71 || 53. 5 || 53. 3 || 53. 1 || 52.8
32 | 19. 9 || 19. 8 || 19. 6 || 19. 5 72 | 54. 3 || 54. 1 || 53. 9 || 53. 6
33 20. 8 || 20. 6 | 20. 5 20.4 73 || 55. 2 | 55. 0 || 54. 7 || 54. 4
34 || 21. 6 || 21. 5 || 21. 4 || 21. 3 74 || 56. 0 || 55. 8 || 55. 6 || 55.3
35 22. 5 22. 4 22. 3 22. 2 75 56. 8 || 56. 6 56.4 56. 1
36 || 23. 4 || 23. 3 || 23. 2 23. 1 76 57. 7 || 57. 5 57. 2 56.9
37 24, 3 || 24. 2 | 24. 0 || 23. 9 77 58. 5 58. 3 || 58. 1 || 57. 8
38 || 25. 2 || 25. 1 || 24, 9 || 24. 8 78 59. 4 || 59. 2 | 58, 9 58. 6
39 26. 1 || 26. 0 || 25. 8 || 25. 7 79 || 60. 2 60. 0 || 59. 8 || 59. 5
40 26. 9 26. 8 || 26. 6 26. 5 80 | 61. 1 || 60. 9 || 60. 6 60. 3
41 27, 8 27, 7 27. 5 27.4 81 61. 9 || 61. 7 || 61. 4 || 61. 1
42 28. 7 || 28. 6 || 28. 4 || 28. 3 82 | 62. 8 || 62. 5 || 62. 3 || 62. 0
43 29. 5 29. 4 || 29. 2 29. 1 83 || 63. 6 || 63. 3 || 63. 1 || 62. 8
44 30, 4 || 30. 3 || 30. 1 || 30. 0 84 || 64. 4 || 64. 2 63. 9 || 63. 6
45 || 31. 3 || 31. 2 || 31. 0 || 30. 8 85 65. 2 || 65. 0 || 64, 8 || 64. 5
46 || 32. 2 | 32. 0 || 31. 9 || 31. 7 86 | 66. 0 || 65. 8 || 65. 6 || 65. 3
47 || 33. 0 || 32. 9 || 32. 7 32. 5 87 | 66. 9 | 66. 7 | 66. 4 | 66. 1
48 33 g 33, 3 || 33, 6 || 3 || || 3 || 67, 7 || 67 5 || 67 2 | 66 3
49 || 34.8 || 34. 6 || 34. 4 || 34. 2 89 | 68. 5 | 68. 3 | 68. 1 | 67. 8
50 | 35. 6 || 35. 4 || 35. 2 | 35. 0 90 | 69. 3 || 69. 1 | 68. 9 | 68. 6
600
Circular of the National Bureau of Standards
TABLE 94.—Ratio of levulose to total sugar from the Lane and Eymon titration and
Nyns “apparent” levulose—Continued

TXl TXl
100 T= 15 T-25 || T=35 | T=45 100 T= 15 T-25 || T=35 | T=45
91 || 70. 2 || 70. 0 69. 7 || 69. 4 111 86. 7 86. 4 || 86. 0 85. 7
92 || 71. 0 || 70. 8 || 70. 6 || 70. 3 112 87. 5 87. 2 86. 8 || 86. 5
93 || 71.9 || 71. 7 || 71. 4 || 71. 1 113 88. 3 88. 0 87. 6 87. 3
94 | 72. 7 | 72.5 | 72. 3 || 72. 0 114 89. 1 88. 8 || 88.4 88. 1
95 || 73. 5 || 73. 3 | 73. 1 || 72. 8 115 90. 0 | 89. 6 | 89. 3 88. 9
96 || 74. 3 || 74. 2 | 73. 9 || 73. 6 116 || 90. 8 || 90. 4 | 90. 1 89. 7
97 || 75. 2 || 75. 0 || 74. 7 || 74. 4 117 91. 6 91. 3 || 91. 0 90. 6
98 || 76. 0 || 75. 8 || 75. 6 || 75.3 118 || 92. 4 || 92. 1 92. 8 || 91.4
99 || 76. 8 || 76. 6 || 76. 4 || 76. 1 119 93. 2 | 92. 9 92. 6 || 92. 2
100 77. 6 77. 4 || 77. 2 | 76.9 120 94. 0 || 93. 7 || 93.4 || 93.0
101 78. 5 || 78. 2 | 78. 0 || 77. 7 121 94. 8 || 94. 5 | 94. 2 93. 8
102 || 79. 3 || 79. 0 || 78. 8 || 78. 5 122 95. 6 || 95. 3 || 95. 0 94. 6
103 80. 1 79. 9 79. 6 || 79. 3 123 96.4 96. 1 95. 8 || 95.4
104 || 81. 0 || 80. 7 || 80. 4 || 80. 1 124 || 97, 3 || 97. 0 || 96. 6 96. 2
105 || 81. 8 || 81. 5 81. 2 | 80. 9 125 98. 1 97. 8 || 97. 4 || 97. 0
106 || 82. 6 82. 3 || 82. 0 || 81. 7 126 98.9 || 98. 6 98. 2 | 97.8
107 || 83. 5 | 83. 2 | 82. 8 || 82. 5 127 99. 7 || 99. 4 || 99. 0 98. 6
108 | 84.3 | 84. 0 83. 6 || 83. 3
109 || 85. 1 84. 8 || 84. 4 | 84. 1
110 85. 9 || 85. 6 85. 2 | 84. 9
--
Polarimetry, Saccharimetry, and the Sugars 601
TABLE 95.-Ratio of levulose to total sugar from the Lane and Eynon titration and
the polarization by the Mathews formula
[The table gives the percentage ratio (R) of levulose to total reducing sugar
calculated from the Lane and Eynon titration and the direct polarization at 20° C.
P is the polarization in *S; T is the corrected Lane and Eynon titer; D is the
number of volumes to which one volume of the solution polarized was diluted for
the titration; and f is the factor used for correcting the percentage ratio found
in the table. This correction is given by f XD/T and is to be added algebraically.
The table can be used when the polarization is made at a temperature other
than 20° C by using the temperature coefficient, AR/At°. When the temperature
is tº, he correction is (AR/At°) (tº —20°), and is to be added algebraically to the
ratio.

P.T. AR P. T. AR
#- |T-15|T=25. T=35 | T=45 ſ At 9 # T=15|T-25 T-35|T-45| f | xià
37 |–0, 6 ||—0. 4 || –0. 3 || –0.2 0.29 || 0 — 18 || 52.2 52.2 52. 1 || 52. 1 | —. 35 | . 23
36 |+0.4 |+0.5 +0. 7 || --0.8 . . 28 || 0 — 19 || 53.2 53. 1 || 53. 1 || 53.0 —. 36 . 23
35 | 1.4 | 1.5 | 1.6 | 1. 7 | . 27 | 0.01 –20 || 54.2 54. 1 54.0 | 54.0 | —. 37 . 24
34 || 2.3 || 2.4 || 2.6 || 2.7 26 01 –21 || 55. j | 55. 0 || 55.0 || 54.9 —. 38 . 24
33 3.3 || 3. 4 || 3. 5 || 3, 6 24 02 —22 || 56. 1 || 56. 0 || 56.0 || 55.9 || –. 39 . 24
32 || 4.2 || 4.4 || 4.5 || 4.6 23 , 02 —23 57. 0 || 57. 0 || 56.9 56.8 || –. 40 25
31 5. 2 5. 3 || 5. 4 || 5.5 22 . 02 –24 || 58.0 57.9 || 57.9 57.8 || –. 42 25
30 6.2 6. 3 || 6.4 6.5 21 . 03 –25 | 59. 0 || 58.9 || 58.8 58. 7 || –. 43 26
29 || 7. 1 || 7. 2 | 7.3 || 7.4 20 | . 03 –26 || 59.9 || 59.8 || 59.8 || 59, 7 || —. 44 26
28 8. 1 8. 2 | 8.3 || 8.4 19 | . 04
–27 | 60.9 || 60, 8 || 60. 7 || 60, 6 || —. 45 27
27 9.0 9. 1 || 9. 2 || 9.3 18 . 04 –28 || 61.8 || 61. 7 || 61. 7 || 61. 6 —. 46 27
26 || 10. 0 || 10, 1 || 10. 2 | 10. 3 16 . 04 –29 || 62.8 || 62. 7 62. 6 || 62.5 | —. 47 27
25 | 11. 0 | 1.1. 1 || 1 1. 1 || | 1.2 15 . 05 –30 || 63.8 || 63. 7 || 63.6 || 63.5 —. 49 28
24 || 11.9 || 12. 0 || 12. 1 || 12.2 14 . ()5
23 12.9 || 13. 0 || 13. 1 || 13. 1 13 06 —31 || 64.7 64. 6 || 64, 5 || 64.4 | —. 50 . 28
—32 || 65. 7 || 65. 6 || 65. 5 || 65. 4 || –. 51 . 29
22 || 13.8 || 13.9 14. 0 || 14. 1 | . 12 . 06 —33 | 66.6 | 66.5 | 66.4 | 66. 3 | —. 52 | . 29
21 || 14.8 14.9 || 15. 0 || 15. 0 | . 11 . 07 –34 67.6 || 67.5 | 67.4 || 67.3 —. 53 . 29
20 | 15.8 15.8 15.9 || 16. 0 | . 09 . 07
19 | 16. 7 | 16. 8 || 16.9 | 16.9 | . 08 . 07 —35 | 68.6 | 68.4 | 68.3 | 68. 2 | —. 54 . 30
18 || 17. 7 || 17.7 || 17.8 17. 9 . 07 | . 08 –36 || 69.5 || 69.4 || 69. 3 || 69.2 —. 56 . 30
–37 || 70. 5 || 70.3 || 70. 2 || 70. 1 || –. 57 . 31
17 | 18.6 | 18.7 | 18.8 | 18.8 | . 06 .08 –38 71. 4 || 71. 3 || 71.2 71. 1 || —. 58 .31
I6 | 19.6 | 19.6 || 19, 7 || 19.8 05 . 09 —39 || 72, 4 || 72, 3 || 72, 1 || 72.0 | —. 59 32
15 20.6 20.6 20. 7 || 20. 7 | . 04 . 09
14 21.5 || 21.6 || 21.6 || 21. 7 | . 02 | . 10 –40 | 73.4 | 73. 2 | 73. 1 | 73.0 | —. 60 . 32
—41 || 74.3 || 74. 2 | 74. 1 | 73.9 | —. 61 . 32
13 22. 5 22. 5 || 22.6 || 22.6 | . 01 ... 10 —42 75.3 || 75, 1 || 75. 0 || 74.9 || —. 63 . 33
12 || 23.4 || 23.5 || 23. 5 || 23.6 | . 00 | . 10 —43 || 76.2 || 76. 1 || 76. 0 || 75.8 || —. 64 33
11 || 24.4 || 24. 4 || 24.5 | 24.5 | –. 01 11 —44 || 77. 2 || 77, 0 || 76.9 || 76.8 —. 65 34
10 || 25.4 || 25.4 || 25. 4 || 25. 5 | —. O2 11
—45 || 78.2 || 78, 0 || 77.9 || 77.7 —. 66 . 34
9 26.3 || 26.4 26.4 || 26.4 || –. 03 . 12 –46 || 79. 1 || 79, 0 || 78.8 || 78.7 | –. 67 . 34
8 || 27, 3 || 27.3 27.3 27. 4 || –. 05 . 12 —47 || 80. 1 || 79.9 || 79.8 || 79.6 — . 68 . 35
7 | 28. 2 || 28. 3 || 28.3 || 28.3 | —. O6 . 12 –48 || 81. 0 | 80.9 || 80. 7 || 80.6 || —. 69 . 35
6 || 29. 2 29, 2 | 29, 3 || 29.3 | –. 07 . 13 –49 || 82. 0 || 81.8 || 81.7 | 81.5 | —. 71 . 36
5 || 30.2 30, 2 || 30, 2 || 30, 2 | —. OS . 13 —50 83. 0 || 82, 8 || 82.6 || 82.5 — . 72 . 36
4 || 31. 1 || 31. 1 || 31.2 || 31.2 —. O9 . 14 —51 | 83.9 || 83. 7 | 83.6 || 83.4 —. 73 . 37
3 || 32. 1 || 32. 1 || 32. 1 || 32. 1 || –. 10 . 14 —52 | 84.9 | 84. 7 | 84. 5 | 84.4 || –. 74 . 37
2 33. 0 || 33.0 || 33. 1 || 33. 1 || –. 11 . 14 –53 | 85.8 || 85. 7 || 85. 5 || 85.3 | —. 75 . 37
_*|#}|{}}| #}| #}| L:#| #| – | 87.8 |8.5 | 8.4 || 8.3 |-|3| 3:
–3 ||3:? |33 || 3 || 3 || - is ié || L: ||...} | . ; ; ; ##| L: | #
–3 || 37.8 37.8 || 37.8 37.8 —. 17 17 * e tº * g
e –58 90.6 90.4 90.3 | 90. 1 —. 81 . 39
–4 || 38.8 || 38.8 || 38.8 || 38.8 || –. J.8 . I7
–5 || 39.8 || 39.8 || 39, 7 || 39, 7 || –. 20 . 17 –59 91.6 | 91.4 || 91.2 | 91.0 | —. 82 40
–6 | 40. 7 || 40. 7 | 40. 7 | 40. 7 || —. 21 . 18 —60 92.6 92.3 | 92.2 | 92.0 | —. 83 40
–7 || 41. 7 || 41.7 || 41.6 || 41.6 | —. 22 . 18 –61 | 93.5 | 93.3 || 93.1 92.9 || –. 85 41
—8 || 42.6 || 42.6 || 42.6 || 42.6 | —. 23 | . 19 –62 94.5 | 94.3 94.1 | 93.9 || –. 86 41
–9 || 43.6 43.6 || 43.6 || 43.5 —. 24 . 19 –63 | 95.4 | 95. 2 | 95.0 | 94.8 || —. 87 .42
– 10 || 44. 6 || 44.5 44.5 || 44.5 ! —. 25 . 19
–64 || 96.4 96.2 | 96.0 | 95.8 —. 88 . 42
– 11 || 45. 5 || 45. 5 || 45. 5 || 45.4 —. 27 . 20
–65 97.4 || 97. 1 || 96.9 || 96.7 —. 89 42
— 13 47.4 47.4 || 47.4 || 47.3 | —. 29 . 21 • *…* | *ººe e tº
— 14 || 48.4 || 48.4 || 48.3 48.3 —. 30 . 21 –67 || 99.3 || 99.0 | 98.8 || 98.6 || —. 92 . 43
— 15 49.4 || 49.3 || 49.3 || 49. 2 | —. 31 22 –68 ||100.2 |100. 0 || 99.8 99, 6 —. 93 . 44
– 16 || 50.3 || 50, 3 || 50.2 || 50. 2 | —. 32 | . 22 –69 || 101. 2 | 101. 0 || 100. 7 || 100. 5 | —.94 . 44
– 17 | 51.3 || 51.2 || 51.2 || 51. 1 | —. 34 . 22 –70 102.2 101.9 || 101.7 | 101.5 —.95 . 44
602
Circular of the National Bureau of Standards
TABLE 96.-Schoorl method for the determination of reducing sugar in came molasses
Reducing sugars
Copper Pol. 10° POl. 20° POl. 30° PO1. 40° Pol. 60°
mg Percent Percent Percent Percent Percent
100 8. 70 . 60 . 57 . 55 8. 53
120 10. 44 10. 36 10. 32 10. 28 10. 28
j 40 12. 20 12. 11 12. 09 12. 06 12. 04
160 14. 03 13. 95 13. 89 13. 87 13. 8]
180 15. 84 15. 78 15. 69 15. 66 15. 60
200 17, 70 17. 63 17. 53 17. 50 17. 43
220 19, 54 19. 50 19. 44 19. 36 19, 25
240 21. 40 21. 36 21. 28 21. 20 21. 12
260 23. 27 23. 22 23. 13 23. 05 22. 97
280 25, 16 25. 12 25. 02 24, 91 24. 83
300 27. ().5 27. 00 26. 95 26, 90 26. 80
320 29. 07 29. 0 | 28. 95 28. 90 28. 80
340 31. 11 31. 05 30, 98 30. 91 30. 77
360 33. 18 33. 11 33. 04 32, 96 32. 82
380 35. 28 35. 15 35, 08 35. 01 34. 89
400 37. 40 37. 27 37. 20 37. 13 37. 00
TABLE 97.-Luff and Schoorl method for the determination of invert sugar in came
Sugar
| Invert sugar in reaction mixtures containing—
Thiosulfate,
0.1 N 1.25 f
No sucrose sº 2.5 g of sucrose 5 g of sucrose
ml mg ºng mng mg
0. 0 0.00 --------------|--------------|--------------
. 4 1. 40 1. 00 0. 60 (). 15
. 5 1. 75 1. 30 . 90 . 45
1. 0 3. 50 2. 90 2. 50 2. 00
2. () 6. 55 5. 90 5. 50 5. 00
4. 0 12. 55 11. 90 11. 50 | 1, 00
6. 0 18, 60 18. 00 17. 50 17. 00
8. 0 24. 70 24. 10 23. 55 23. 00
10. 0 30, 85 30, 25 29. 75 29. 05
12. 0 37. 10 36. 55 36. 15 35. 30
14. 0 43. 50 42. 95 42. 50 41. 70
16. 0 50. 20 49. 65 49. 15 48. 30
Polarimetry, Saccharimetry, and the Sugars
603
TABLE 98.-Somogyi deactrose—thiosulfate equivalents
[Amounts of dextrose corresponding to titration values when 5 ml of Solution and 5 ml of copper reagent
modified) are heated in a water bath for 15 minutes]
Thio-
sulfate,
0.005 N
ml
Tenths of 1 ml of 0.005 N. sodium thiosulfate
0 | 2 3 4 5 7 8 9
Milligrams of dextrose in 5 ml of solution
<-- - - - - -- I - - - - - - 0. 11 || 0 1 2 0. 13 || 0. 15 0. 16 (). 17 | (). 18 (0. 20
. 21 . 22 . 23 | . 25 . 26 . 27 | . 28 . 29 . 31 | . 32
. 33 . 34 . 35 . 36 | . 38 . 39 . 40 . 41 . 42 | . 43
. 45 . 46 . 47 | . 485 495 : 505| . 515 . 530| . 540 - 550
. 565 575 585 595) . 605 | . 620 630 - 640 . 650 - 660
. 670| . 685| . 695) . 705 715 730 - 740 - 750) . 760 - 770
. 785 . 795 . 805 815| . 825 840 - 850 860 . 870 - 880
. 895| . 905 915 . 925| . 935 | . 950 960 . 970 . 980 . 995
1. 005| 1. 015 025 1. 035| 1. 050| 1. 060. 1. 070| 1. 080| 1. 0901. 105
1. 115| 1. 125 1. 135| 1. 115| 1. 116 1. 117| 1. 185| 1. 195| 1. 2051. 215
1. 225| 1. 24 | 1. 25 | 1. 26 | 1. 27 | 1. 28 | 1. 295| 1. 305| 1. 315||1. 325
1. 335| 1. 35 | 1. 36 | 1. 37 | 1. 38 | 1. 395| 1. 405 1. 415 1. 425||1. 44
1. 450 1. 460. 1. 470| 1. 480| 1. 495| 1. 505| 1. 515| 1. 525 1. 54 |1. 55
1. 560. 1. 570) 1. 580. 1. 590. 1. 605 | 1. 615 1. 63 | 1. 640| 1. 6501. 660
1. 670 | 1. 685| 1. 695| 1. 705 1. 715 1. 725 1. 735| 1. 750| 1. 760|1. 170
1. 780| 1. 795| 1. 805 1. 815| 1. 825 | 1. 835 | 1. 850 1. 860| 1. 870|1. 880
1. 89 | 1. 905| 1. 915| 1. 930| 1. 940| 1. 950|| 1. 960| 1. 970| 1. 98 |1. 990
2.00 ------|------|------|------|------|------|------|-----------
1 M. Somogyi, J. Biol. Chem.
70, 607 (1926).
1 ml of 0.005 N thiosulfate equals 0.318 mg of copper.
604 Circular of the National Bureau of Standards
TABLE 99.-Hagedorn and Jensen dextrose equivalents
Hundredths of 1 ml of 0.005 N. sodium thiosulfate
Sodium -
thio- .00 01 | .02 03 04 05 06 07 08 09
sulfate, * º sº g & & & e e
0.005 N
Milligrams of dextrose
ml
0 0 || 0.385| 0.382| 0.379 0, 376 0.373| 0.370| 0.367| 0.364| 0, 361|0. 358
... 1 . 355 . 352 . 350 . 348 . 345 . 343| . 341| . 338|| . 336|| . 333
... 2 . 331. . .329 . 327 . 325| . 323] .. 321| . 318 . .316) .. 314| . 312
. 3 . 310| 308| 306 . 304 . 302 - 300 . 298 . 296 . 294 | . 292
. 4 . 290 . 288 . 286. . 284 . 282 . 280 . 278 . 276 , 274 . 272
. 5 . 270. . 268 . 266 , 264 . 262 . 260 . 259 . 257 . 255 . 253
... 6 . 251 . 249| . 247 . 245 . 243| . 241 | . 240 - 238 . 236| . 234
7 . 232 . 230|| 228 . 226 . 224| . 222 - 221 | . 219 - 217 - 215
... 8 . 213 . 211 . 209 . 208 . 206 . 204 . 202: . 200 . 199| . 197
. 9 . 195 . 193 . 191 . 190 - 188 . 186 - 184 - 182 - 181 | . 179
1. 0 . 177| . 175 . 173 . 172 . 170 - 168 - 166. , 164 . 163| . 161
1. 1 . 159 . 157 . 155 . 154 . 152 . 150 . 148 . 146 - 145|. 143
1. 2 . 141 . 139 , 138|| . 136|| . 134 . 132 . 131 | . 129| . 127| . 125
1. 3 . 124 . 122 , 120 . 119| . 117| . 115| . 113| . 111 | . 110| . 108
1. 4 ... 106| . 104. , 102 . 101| . 099] . 097 . 095 . 0.93| . 092] . 090
1. 5 . 088 . 086 - 084 - 083| . 0.81| . 079| . 0.77| . 075 . 074 - 072
1. 6 . 070 . 068| . 066|| . 065| . 063| . 061 | . 059 . O57| . 056 . 054
1. 7 . 052| . 050 . 048 . 047] . 045| . 043 . 041 - 0.39| . 038| . 036
1. 8 . 034 . O32 . 031| . 029 . O27 . 025 - 024 . O22 . 020 - 019
1. 9 . 017| . 015| . 014 . O12 . 010| . 008 . 007 . 005 . 003 . 002
Polarimetry, Saccharimetry, and the Sugars 605
TABLE 100.-Pot method of Main for invert sugar
[Using Fehling solution, Soxhlet modification; time of heating in boiling water, 5 min.; indicator, 2 drops
of 1-percent methylene blue in each tube]
Sucrose g/100
m!-------- 0 to 1 0 1. 1 I 2. 5 2. 5 5 10
Fehling solu-
tion, ml- - - 20 10 10 5 2. 5 5 2. 5 2. 5 2. 5
Solution re-
quired for Invert sugar/100 ml Invert sugar
reduction
ml g g g % % % % % %
15 |0. 648 |0. 330 |0. 325 |16. 6 8. 58 || 6. 60 | 3. 35 | 1. 61 0. 742
16 | . 608 | . .309 | . 306 |15. 6 || 8. 06 || 6, 15 || 3. 12 | 1. 50 . 698
17 | . 574 | . 290 . . 288 |14. 7 7. 60 | 5. 78 || 2, 94 | 1. 41 . 658
18 . 543 | . 274 . 272 |13. 9 7. 18 || 5. 46 2. 78 | 1.33 . 620
19 | . 514 | . 260 . . 258 |13. 2 6. 80 5, 17 | 2, 63 | 1. 26 . 584
20 | . 487 | . 248 . 246 |12. 5 6. 45 || 4. 90 2. 49 | 1. 19 . 551
21 | . 462 | . 237 | . 235 |11. 9 6. 14 || 4, 66 2. 37 | 1. 13 . 520
22 | . 440 | . 226 | . 224 |11. 4 5. 86 || 4, 45 2. 26 | 1. 08 . 493
23 | . 420 | . 216 | . 214 |10. 9 5. 60 || 4, 26 || 2. 16 | 1. 03 . 470
24 | . 402 | . 206 | . 205 |10. 5 5. 36 || 4. 08 || 2, 06 | . 975 . 450
25 | . 387 | . 198 | . 197 |10. 1 5. 14 3. 90 | 1. 98 | . 935 . 432
26 | . 374 | . 190 | . 190 9. 70 || 4. 94 | 3. 76 | 1. 90 | . 902 . 416
27 | . 361 | . 183 | . 183 || 9, 34 || 4. 76 || 3. 62 | 1. 82 | . 870 . 400
28 . 349 | . 177 | . 177 9. 00 || 4, 58 || 3. 49 | 1. 75 . 840 . 386
29 | . 337 | . 171 | . 171 8. 70 4, 42 || 3. 37 | 1. 69 ... 812 . 373
30 | . 326 | . 165 | . 165 | 8.40 || 4, 28 3. 26 | 1. 63 . 788 . 361
31 | . .316 | . 160 | . 160 8. 15 || 4. 14 || 3. 15 1, 57 | . 760 . 349
32 | . 306 | . 155 . 155 7. 90 || 4, 01 || 3. 04 || 1. 52 | . 735 . 338
33 | . 297 | . 151 | . 151 7, 65 || 3. 89 2.95 | 1. 47 | . 710 . 328
34 | . 288 . . 147 | . 147 | 7. 45 3. 78 || 2. 87 | 1. 43 | . 690 . 319
35 | . 280 | . 143 | . 143 7. 25 3. 68 || 2, 80 | 1. 40 | . 670 . 312
2
3
414°—42——40
o
º
606
Circular of the National Bureau of Standards
TABLE 101.-Pot method of Main for small quantities of invert sugar !
{Using a Fehling Solution containing potassium ferrocyanide; indicator, 2 drops of 1-percent methylene
blue in each tube]

Sucrose, g/100 ml ---- 5| 10 20 20 2. so 20 30
L. F. S. extra alka- | |
line, ml ----------- . 4 4 4 2 1. 1. 1. 1
Time of heating in |
boiling water, min- 5 5 5 5 5 5 o 10
solutiºn lººd for Invert sugar/100 ml Invert sugar
ml 9 g g g % % % %
| 5 || 0 832| 0. 3840. 182 |0. 0.878||0. 03900. 0265|0. 0.1060. 0085
| 6 . 779. , 356 . 170 . 0828 . 0381 | . 0251 | . 0095|.. 0071
17 . 740. . .338 . 161 | . 0783| . 0368 . 0229| . 0086| 0060
18 . 704. . .324 . 153 . 0739| . 0348 . 0208 . 0079| . 0052
19 . 670 - 310| . 146 . 0697| . 0323| . 0191 | . 0074 - 004.5
20 . 638|| . 296 . 140 | . 0660 . 0299| . 0177 . 0069| . 0040
21 . 608 . 283 . 134 | . 0628| . 0279| . 0166 . 0065 . 0035
22 . 581 | . 270. . 128 . 0600 . 0262| . 0158| . 0061 | . 0031
23 . 556 . 256 . 123 . 0575|| . 0249) . 0151 | . 0.058 . 0028
24 . 533 . 243| . 118 . 0553| . 0237| . 0145| . 0055| . 0025
25 . 512| . 232 . 113 | . 0530| . 0226 . 0.139| . 00.52|_ _ _ _ _ _
26 . 493| . 222| . 109 | . 0510| . 0216 . 0133| . 0050| . 0020
27 . 476 . 215| . 105 | . 0491 | . 0207 . 0128| . 0047|_ _ _ _ _ _
28 . 459| . 209| . 101 | . 0473| . 0198 . 0123| . 004.5 . 0015
29 . 444 . 203| . 097 | . 0455 , 0.190| . 0119) . 0043|_ _ _ _ _ _
30 . 429 . 198| . 0935 . 0438 . 0182| . 011.4| . 004 || . 001()
31 . 415 - 193| . 090 | . 0424| . 0175|| . 0109|_ _ _ _ _ _ _ _ _ _ _ _
32 . 402 . 189 . 0865. . 0408 . () 168| . 0.105|_ _ _ _ _ _ - - -
33 . 390 - 185| . 083 | . 0393 - 0162| . 0.101|_ _ _ _ _ _ _ _ _ _ _ _
34 . 380 . 181 - 080 | . 0.380 . 01:56 . 0.097|_ _ _ _ _ _ -
35 . 370 - 178 . 0.765 . 0369| . 0151 | . 009.4|_ _ _ _ _ _ _ _ _ _ _ _
1 Int. Sugar J. 34, 213 (1932).
Polarimetry, Saccharimetry, and the Sugars 607
TABLE 102.-Sichert and Bleyer modification of the Barfoed copper acetate method
for hearoses 1
Tenths of 1 ml of 0.1 N permanganate
Per-
IIla, Il- ! -
gan- ſº |
fate, 0 0.1 0.2 0.3 0.4 0.5 0.6 of os 0.9
0.1 N
titer
1Ue Milligrams of dextrose
ml
10 || 26. 5 || 26, 8 || 27. 1 || 27. 4 || 27, 8 28. 1 || 28. 4 || 28. 7 || 29. 0 || 29. 3
11 29, 7 || 30, 0 || 30, 4 || 30. 7 || 31, 1 || 31, 5 || 31, 8 || 32. 2 | 32. 6 || 32.9
12 33. 3 || 33. 7 || 34. 1 || 34. 5 || 34, 9 || 35. 4 || 35. 8 || 36. 2 || 36. 6 || 37. 0
13 || 37. 4 || 37, 9 || 38. 4 || 38. 8 || 39. 3 || 39, 8 || 40. 2 | 40. 7 || 41. 2 41. 7
14 || 42. 2 || 42. 7 || 43. 2 || 43. 8 44, 3 || 44. 9 45. 4 || 46. 0 || 46. 5 || 47. 0
15 || 47. 6 || 48. 2 || 48. 8 || 49. 4 || 50. 1 || 50, 7 || 51. 3 || 51.9 52. 5 || 53. 2
16 53. 8 || 54. 5 55. 2 | 55. 9 56. 6 57. 3 || 58. 0 || 58. 7 || 59. 4 || 60. 2
17 | 60. 9 || 61. 7 || 62. 5 || 63. 3 || 64. 1 || 64. 9 || 65. 7 | 66. 5 || 67. 4 | 68. 2
18 69. 0 || 69. 9 || 70. 9 71. 9 || 72. 8 || 73. 8 || 74, 8 || 75. 7 || 76, 7 || 77. 6
19 || 78. 6 || 79. 6 80. 7 || 81. 7 || 82. 7 || 83. 7 | 84. 8 || 85. 8 || 86. 8 87. 8
20 | 88. 9 90. 0 || 91. 2 92. 3 || 93. 5 94. 7 || 96. 0 || 97. 2 98. 5 99. 7
1 The table may be interpolated for hundredths of a milliliter, but should not be extrapolated.
608 Circular of the National Bureau of Standards
TABLE 103. –Van der Haar mucic-acid equivalents of galactose
Mucic acid obtained when Mucic acid obtained
sample contains— when sample contains—
Galac- Galac-
tose Galactose-Hsu- tose Galactose-H su-
Galactose | crose to equal Galactose | crose to equal
1,000 mg 1,000 mg
ng mg mg ng ng mg
O — 4 — 4 500 366 360
10 –H 0.8 +2.4 510 374. 9 368
20 5. 6 8. 8 520 383. 8 376
30 10. 4 15. 2 530 392. 7 384
40 15. 2 21, 6 540 401. 6 392
50 20 28. 0 550 410. 5 400
60 27 34.9 560 419.4 408
70 34 4.1. 8 570 428. 3 416
80 41 48. 7 580 437. 2 424
90 48 55. 6 590 446. 1 432
100 55 62. 5 600 455 440
110 64 70. 0 610 462 447
120 73 77. 5 620 469 454
130 82 85. 0 630 476 461
140 91 92. 5 640 483 468
150 100 100. () 650 490 475
160 108. 4 106. 6 660 497 483
170 116. 8 113. 2 670 504 491
180 125. 2 119. 8 680 511 499
190 133. 6 126. 4 690 518 507
200 142. 0 133. 0 700 525 515
210 149. 6 139. 4 710 534 523
220 157. 2 145. 8 720 543 531
230 164. 8 152. 2 730 552 539
240 172. 4 158. 6 740 561 547
250 180 165 750 570 555
260 187 173 760 579 564
270 194 181 770 588 573
28U 201 189 780 597 582
290 208 197 790 606 591
300 215 205 800 615 600
310 223. 1 212 810 623 609
320 231. 2 219 820 631 618
330 239. 3 226 830 639 627
340 247. 4 233 840 647 636
350 255. 5 240 850 655 645
360 263. 6 248. 8 860 663 654
370 271. 7 257. 6 870 671 663
380 279. 8 166. 4 880 679 672
390 287. 9 275. 2 890 688 681
400 296 284. 0 900 695 690
410 303 292. 2 910 703. 5 699
420 310 300. 4 920 712 708
430 317 308. 6 930 720. 5 717
440 324 316. 8 940 729 726
450 331 325 950 737. 5 735
460 338 332 960 746 744
470 345 339 970 754. 5 753
480 352 346 980 763 762
490 359 353 990 771. 5 771
1, 780 780
000
Polarimetry, Saccharimetry, and the Sugars
609
TABLE 104.—Steinhoff table for estimation of dea:trose, maltose, and deatrim
1 2 3 4
0.1. N
Iodine Analysis Analysis Maltose by Analysis
A. B difference C
ml. *ng. 7ng. mg. ºng.
1 6. 1 1. 9 5. () 3. 2
2 8. 6 2. 7 10. 5 6. 3
3 11. 2 3. 6 16. 0 9. 4
4 13. 4 4. 3 21. 5 12. 6
5 15. 6 4. 9 27. 0 15. 9
6 18. 1 5. 7 32. 5 19. 2
7 20, 5 6.4 38. 0 22. 4
8 23. 2 7. 3 43. 5 25. 6
9 25. 8 8. 1 49. 0 28, 9
10 28. 4 8. 9 55. 0 32. 3
11 31. 2 9. 7 60. 5 35. 7
12 34. 2 10. 6 66. 0 39. 0
13 37. 3 11. 5 72. 0 42. 4
14 40. 5 12.4 78. 0 45. 8
15 46, 8 14. 3 83. 5 49, 3
16 52. 8 16. 0 89. 0 52. 8
17 58. 6 17, 7 95. 0 56. 3
18 66. () 19. 8 101. 0 59. 8
19 73. 4 21. 8 107. 0 63. 3
20 80. 0 23.4 112. 5 66. 9
21 88. 4 25.4 118. 5 70. 7
22 96. 2 27. 3 124. 5 74. 5
23 ----------|---------- 130. 5 78. 5
24 ||-------------------- 136. 5 82. 6
25 ----------|---------. 142. 5 86. 6
26 ----------|---------- 148. 5 90. 7
27 ----------|---------- 154. 5 94. 8
610
Circular of the National Bureau of Standards
TABLE 105.- Kröber table for the determination of pentoses and pentosans
Furfural
phloro- Furfural Arabinose
glucide
(ſ g g
(). 030 0.0182 0.0391
. 032 . 0193 . 0413
. 034 . 0203 . 04:35
. . 036 . 0214 . 0457
. 038 . 0224 . ()479
. 040 , 0235 . 0501
. 042 . 0.245 0523
. 044 . 0255 . 0545
, 046 . 0.266 . 0567
, 0.48 . 0.276 0589
, ()50 . 0286 . 06il
. 052 . 0.297 0633
. 054 . O307 . ()655
. 056 . 0318 . 0677
. ()58 . 0328 . 0699
. 060 . ()338 ()72]
. 062 . 0349 0743
, ()64 . 0359 0765
. 066 . ()370 ()787
. Ot;8 , 0.380 0809
. 070 . ()390 . ()83]
. ()72 . 040l . ()853
074 . 0411 , 0875
076 . 0422 . O897
. 078 . 0432 . 0.919
. 080 . 0442 . 094]
082 . 0453 . 0.963
. 084 . ()463 . 0985
. 086 . 0474 ... 1007
. 088 . ()484 1029
. O90 0494 1051
. O92 . 0505 1073
. ()94 . 0515 1095
. O96 . ()525 . I 17
. ()98 O536 . 1139
... 100 0546 . 1161
102 0557 1182
. 104 0567 1204
. 106 . ()577 . 1226
... 108 . 0588 . 1248
. 110 . O598 . 1270
. 112 . 0608 . 1292
. 114 . 0619 . 1314
. 116 . 0619 . 1336
. 118 . 0640 . 1358
. 120 . 0650 . 1380
. . 22 . 0660 . 1402
. 124 . 0671 . 1424
. 126 . 0681 . 1446
. 128 . 0691 . 1468
. 130 . 0702 . 1490
. 132 . 0712 . 1512
. 134 . 0723 . 1534
. 136 . 0733 . 1556
. 138 0743 . 1578
. 140 . 0754 . 1600
. 142 . 0764 . 1622
. 144 . 0774 . 1644
. 146 . 0785 . 1666
. 148 0.795 . 1688
. 150 . 0805 . 1710
. 152 . 0816 . 1732
. 154 . 0.826 . 1754
. 156 . 0837 . 1776
. 158 . 0847 . 1798
. 160 . 0857 . 1820
. 162 . 0868 . 1842
. 164 . 0.878 . 1864
. 166 . 0888 . 1886
168 0899 . 1908
Araban
ió03
... 1022
ió60
... 1080
... 1099
. 1118
. 1137
. 1156
. 1176
. 1195
. 1214
. 1233
. 1253
. 1272
. 1292
. 1311
. 1330
. 1350
. 1369
. 1389
. 1408
. 1427
. 1447
. 1466
. 1486
. 1505
. 1524
. 1544
. 1563
. 1583
. 1602
. 1621
1660
. 1679
Xylose Xylan PentOSe PentOSan
ſ] g g
0.0324 0.0285 0.0358 0.0315
. ()342 . 0301 . 0378 0333
. 0361 . 0317 . 0398 . ()350
. 0379 . 0334 . 0418 . ()368
. 0398 . 0350 . 0439 . 0386
, 0.416 . 0366 . 0459 . 0404
. 0434 . 0382 . 0479 . 0422
. 0452 . 0398 . 0499 . 0440
. ()471 . 0414 . ()519 . ()457
. 0489 . 0430 . 0539 . 0475
. 0507 . 0446 . 0.559 . 0492
. ()525 . ()462 . O579 , ()51()
. 0543 . 0478 . 0.599 . ()528
0562 . ()494 . 0620 . ()546
. ()580 . ()510 . 0640 , (),564
. 0598 . 0526 , ()660 . ()581
. ()616 . 05:42 . ()680 . ()599
. ()635 0558 . 0700 , ()617
. 0653 . ()575 . 07.20 . 0634
, ()672 . 0.591 . ()741 . ()652
. ()690 . 0607 . ()761 . ()670
. ()708 , 0623 . ()781 . ()688
. ()726 . O639 . ()801 . ()706
. 0745 . ()655 . 0821 . ()722
. 0763 . 0671 . 0.841 . ()740
. 0.781 . 0687 . 0861 . ()758
0799 . ()703 . 0881 . 0776
. 0.817 . 0719 . 0901 . 0794
0836 , ()735 . 0922 . ()812
. 0854 . 0751 . 0942 0830
. 0872 . ()767 . 0962 . 0847
. 0890 . 0.783 , (),982 , 0.865
. 0909 0800 1002 . 0883
. 0927 . 0.816 1022 . O899
0.946 . 0.832 1043 . 0917
. 0964 . ()848 1063 . 0935
, 0982 . 0.864 1083 . 0953
... 1000 . 0.880 1103 . 0971
. 1019 . 0.896 1123 . 0.988
. 1037 . 0912 1143 , 1006
1055 . 09.28 1163 ... 1023
1073 . 0944 1183 ... 1041
... 109] . 0960 1203 ... 1059
1110 . 0976 1223 ... 1076
1128 . 0992 1243 ... 1094
1146 ... 1008 1263 . 1111
1164 1024 1283 . 1129
. 1182 1040 1303 . 1147
. 120.1 1057 1324 . 1165
. 1219 1073 1344 . 1183
1237 1089 1364 . 120.1
1255 1105 1384 . 1219
1273 1121 1404 . 1236
1292 1 137 1424 . 1253
1310 1153 1444 . 1271
1328 1169 1464 . 1288
1346 1185 . 1484 . 1306
1364 1201 1504 . 1324
1383 . 1217 1525 . 1342
1401 . 1233 1545 . 1360
1419 . 1249 1565 . 1377
1437 . 1265 . 1585 . 1395
1455 . 1281 1605 . 1413
1474 . 1297 . 1625 . 1430
1492 . 1313 . 1645 . 1448
. 1510 . 1329 1665 . 1465
1528 . 1345 1685 . 1483
. 1546 . 1361 1705 . 1501
. 1565 . 1377 1726 . 1519
. 1583 . 1393 1746 . 1537
Polarimetry, Saccharimetry, and the Sugars
611
TABLE 105.-Kröber table for the determination of pentoses and pentosans— Con.

Furfural
phloro- Furfural ArabinoSe Araban Xylose Xylan PentOSe PentOSan
glucide
g g g ſ] g ſ/ 9. 9.
. 170 . 0909 . 1930 . 1698 . 1601 . 1409 . 1766 . 1554
. 172 . 0920 1952 1717 . 1619 . 1425 1786 . 1572
. 174 . 0930 1974 1736 1637 . 1441 1806 . 1590
. 176 . 0940 . 1996 1756 1656 1457 1826 . 1607
. 178 . 0951 . 2018 1775 1674 1473 1846 . 1625
. 180 . 0.961 . 2039 . 1794 . 1692 1489 1866 1642
. 182 . 0971 . 2061 . 1813 . 1710 1505 1886 . 1660
. 184 . 0982 2082 1832 1728 1521 1906 . 1678
. 186 . 0992 2104 1851 1747 1537 1926 1695
. 188 ... 1003 2126 1870 1765 1553 1946 . 1712
. 190 . 1013 2147 1889 1783 . 1569 . 1965 1729
. 192 ... 1023 . 2168 1908 1801 . 1585 . 1985 1747
. 194 ... 1034 . 2190 1927 . 1819 1601 . 2005 1764
. 196 ... 1044 . 2212 1946 1838 . 1617 . 2025 1782
. 198 ... 1054 2233 1965 1856 1633 . 2045 1800
. 200 ... 1065 2255 . 1984 1874 1649 . 2065 1817
. 202 , 1075 2276 . 2003 . 1892 1665 . 2085 1835
. 204 ... 1085 . 2298 . 2022 . 1910 1681 2105 1853
. 206 ... 1096 . 2320 . 2041 1929 . 1697 2125 . 1869
. 208 . 1 106 . 2341 . 2060 1947 . 1713 2144 . 1887
. 210 . l l 16 2363 . 2079 1965 . 1729 . 2164 1904
212 . 1127 2384 . 2098 . 1984 . 1745 . 2184 1922
214 . 1 137 2406 2117 . 2002 1761 . 2204 . 1940
216 ... l l 47 2428 2136 . 2020 1778 . 2224 . 1957
218 . 1158 2449 2155 . 2038 1794 . 2244 . 1974
. 220 . 1 168 . 2471 . 2174 . 2057 . 1810 . 2264 . 1992
. 222 . 1178 . 2492 . 2193 . 2075 1826 . 2284 . 2010
224 . 1189 . 2514 . 2212 . 2093 1842 . 2304 . 2028
. 226 . 1199 2536 . 2232 , 2111 1858 . 2324 . 2046
. 228 . 1209 . 2557 . 2251 2130 1874 . 2344 . 2063
. 230 . 1220 2579 2270 2148 . 1890 2364 . 2081
. 232 . 1230 2600 . 2289 2166 . 1906 2383 . 2097
. 234 . 1240 2622 . 2308 . 2184 1922 2403 2115
. 236 . 1251 2644 . 2327 .2202 1938 . 2423 2132
. 238 . 1261 2665 . 2346 2220 1954 . 2443 2150
240 . 1271 2687 . 2365 2239 . 1970 . 2463 2168
242 . 1281 2708 2384 . 2257 . 1986 . 2483 2185
. 244 . 1292 2730 2403 . 2275 . 2002 . 2503 2203
. 246 . 1302 2752 . 2422 . 2293 . 2018 . 2523 . 2220
. 248 , 1312 2773 . 2441 . 2311 . 2034 . 2543 . 2238
. 250 . 1323 2795 . 2460 . 2330 . 2050 .2563 . 2256
. 252 . 1333 . 2816 . 2479 .2348 . 2066 . 2582 . 2272
. 254 . 1343 .2838 . 2498 . 2366 2082 2602 . 2290
. 256 , 1354 . 2860 . 2517 . 2384 2098 .2622 . 2307
. 258 . 1364 . 2881 2536 2402 . 2114 . 2642 . 2325
. 260 . 1374 . 2903 . 2555 . 2420 2130 , 2662 . 2342
, 262 . 1385 2924 . 2574 . 2438 2146 . 2681 . 2359
, 264 . 1395 2.946 . 2593 . 2456 2162 . 2701 . 2377
. .266 . 1405 2968 , 2612 . 2474 2178 . 2721 . 2394
. 268 . 1416 2989 . 2631 2492 2194 . 2741 . 2412
. 270 . 1426 . 3011 . 2650 . 25.11 . 2210 . 2761 . 2429
. 272 . 1436 . 3032 . 2669 . 2529 2226 . 2781 . 2447
. 274 1447 . 3054 . 2688 . 2547 . 2242 . 2801 . 2465
. 276 1457 . 3076 . 2707 . 2565 2258 . 2821 . 2482
. 278 . 1467 3097 . 2726 . 2583 . 2274 . 2840 . 2499
. 280 1478 3119 2745 . 2602 . 2290 . 2861 . 2517
. 282 . 1488 3140 2764 . 2620 . 2306 . 2880 . 2534
. 284 . 1498 3.162 . 2783 . 2638 . 2322 . 2900 . 2552
. 286 . 1509 3184 . 2802 . 2656 . 2338 , 2920 . 2570
. 288 1519 3205 . 2821 . 2674 . 2354 . 2940 . 2587
. 290 1529 3227 . 2840 . 2693 2370 2960 . 2605
. 292 1540 3248 . 2859 . 2711 . 2386 , 2980 . 2622
. 294 1550 . 3270 . 2878 . 2729 . 2402 .3000 . 2640
. 296 . 1560 . 3292 , 2897 . 2747 . 2418 . 3020 . 2658
. 298 . 1571 . 3313 . 2916 . 2765 2434 . 3040 . 2675
.300 . 1581 . 3335 . 2935 . 2784 2450 . 3060 . 2693
612 Circular of the National Bureau of Standards
TABLE 106.-Apparent weight of water in air
[This table gives the apparent weight for temperatures between 15° and 30° C,
humidity 50 percent, unreduced barometer reading 76 cm, of certain volumes
of water weighed with brass weights. The table may be conveniently em-
ployed to determine definite volumes of water for calibrating instruments.
The air is assumed to be at the same temperature as the water]
*...* |2,000 ml |1,000 ml] 500 ml |400 ml || 300 ml || 250 ml | 150 ml
o C g 9. g g g 9 g
15 | 1996. 11 | 998. 05 || 499. 03 || 399. 22 || 299. 42 249. 51 | 1.49. 71
16 || 1995. 80 | 997. 90 || 498. 95 || 399. 16 || 299. 37 249. 48 || 149. 68
17 | 1995. 48 || 997. 74 || 498. 87 || 399. 10 || 299. 32 249. 43 || 149. 66
18 || 1995. 13 997. 56 || 498. 78 || 399. 03 || 299. 27 | 249. 39 149. 63
19 || 1994, 76 997. 38 || 498. 69 || 398. 95 299. 21 249. 34 149. 61
20 | 1994. 36 || 997. 18 498. 59 || 398. 87 299. 15 249. 30 149. 58
21 | 1993. 95 || 996. 97 || 498. 49 || 398. 79 || 299. 09 || 249. 24 149. 55
22 | 1993. 51 || 996. 76 || 498. 38 || 398. 70 299. 03 249. 19 149. 51
23 | 1993. 06 996. 53 || 498, 26 || 398. 61 298. 96 || 249. 13 149. 48
24 || 1992. 58 || 996. 29 || 498. 15 || 398. 52 | 298. 89 249. 07 149. 44
25 | 1992. 09 || 996. 04 || 498. 02 || 398. 42 298, 81 249. 01 149. 41
26 1991. 57 995. 79 || 497. 89 398. 31 || 298. 74 248. 95 149. 37
27 | 1991. 04 || 995. 52 497. 76 || 398. 21 | 298. 66 248. 88 149. 33
28 1990. 49 995. 24 || 497. 62 || 398. 10 || 298. 57 248. 81 149. 29
29 | 1989. 92 || 994. 96 || 497. 48 || 397. 98 || 298. 49 || 248. 74 149. 24
30 | 1989. 33 994, 66 || 497. 33 397. 87 | 298. 40 248. 67 149. 20
TABLE 107.-Temperature correction for glass volumetric apparatus
[This table gives the correction to be added to actual capacity (determined at
certain temperatures) to give the capacity at the standard temperature, 20° C
Conversely, by subtracting the corrections from the indicated capacity of an
instrument standard at 20° C the corresponding capacity at other temperatures
is obtained. The table assumes for the cubical coefficient of expansion of glass
0.000025 per degree centigrade. The coefficients of expansion of glasses used
for volumetric instruments vary from 0.000023 to 0.000028]
*...* 2,000 ml | 1,000 ml || 500 ml | 400 ml || 300 ml || 250 ml
o C ml ml ml ml ml ml
15 +0. 25 | +0. 12 | +0.06 || +0.05 | +0.04 || --0. 031
16 +. 20 +. 10 +. 05 +. 04 +. 03 || --. 025
17 +. 15 +. 08 +. 04 +. 03 +. 02 || --. 019
18 +. 10 +. 05 +. 02 ––. O2 +. 02 || --. 012
19 +. 05 +. 02 +. 01 +. 01 + 01 | +. 006
21 —. 05 —. 02 —. 01 —. 01 —. 01 | — . 006
22 —. 10 —. 05 —. 02 —. 02 —. 02 | —. O12
23 —. 15 —. 08 —. 04 —. 03 —. 02 —. O19
24 —. 20 —. 10 —. 05 —. 04 —. 03 || –. 025
25 —. 25 —. 12 —. 06 —. O5 —. 04 || —. O31
26 —. 30 —. 15 —. 08 —. 06 —. 04 || —. O38
27 —. 35 —. 18 —. 09 —. 07 —. 05 | —. O44
28 —. 40 —. 20 —. 10 —. 08 —. 06 | —. O50
29 —. 45 —. 22 —. 11 —. 09 —. 07 | —. O56
30 —. 50 —. 25 —. 12 — 10 —. 08 —. O62
Polarimetry, Saccharimetry, and the Sugars
613
TABLE 108.—Reduction of weighings to vacuo
The weight of a body in vacuo is determined by adding to its apparent weight
in air a buoyancy correction equal to the weight of the air displaced by the
difference in volume of the body weighed and the weights required to balance it
on an equal-arm balance.
*.
di ;)
*(1-# ~
k
M_WY #(#)-
*-*-(i. ..)—wº dº)-".
2(d2–di), w kW -º-º-º-º:
WI14;( #)-W4;=W(1+in).
M = Weight in vacuo.
W= Apparent weight in air.
p = Density of air.
di = Density of body.
d2 = Density of weights.
p=0.0012046 (table 29, BS Cir. C19).
s: Correction º Correction s: Correction
Density factor k, Density factor k, Density factor k,
of body brass of body br of body bras
weighed • Weighed rass weighed ass
weights weights weights
g/ml g/ml g/m
0.95 1. 1260 1. 19 0. 8697 1. 43 (). 6996
. 96 1. 1128 1. 20 . 8613 1. 44 . 6937
. 97 1. 0998 1. 21 . 8530 1.45 . 6879
. 98 1. 0.871 1. 22 . 8448 1. 46 . 6822
. 99 1. 0747 1. 23 . 8368 1. 47 . 6766
1. 00 1. 0625 1. 24 . 8289 1. 48 . 6711
1. 01 1. 0505 1. 25 . 8211 1. 49 . 6656
1. 02 1. 0388 1. 26 . 8134 1. 50 . 6602
1. 03 1. 0273 1. 27 . 8059 1. 51 . 6549
1. 04 1. 0160 1. 28 ... 7984 1. 52 . 6496
1. 05 1. 0.050 1. 29 ... 7911 1. 53 . 6444
1. 06 0. 9941 1. 30 . 7839 1. 54 . 6393
1. 07 . 9835 1. 31 . 7769 1. 55 . 6343
1. 08 . 97.31 1. 32 . 7699 1. 56 . 6293
1. 09 . 9628 1. 33 . .7630 1, 57 . 6243
1. 10 . 9527 1. 34 . 7562 1. 58 . 6195
1. 11 . 9428 1. 35 . 7496 1. 59 . 6147
1. 12 . 9331 1. 36 . 7430 1. 60 . 6099
1. 13 . 9236 1. 37 . 7365 1. 61 . 6052
1. 14 . 9142 1. 38 . 7291 1. 62 . 6006
1. 15 . 9050 1. 39 . 7238 1. 63 . 5961
1. 16 . 8960 1. 40 . 7176 1. 64 . 5915
1. 17 . 8871 1. 41 . 7115 1. 65 . 5871
1. 18 . 8783 1. 42 . 7055
614
Circular of the National Bureau of Standards
TABLE 109.- Degrees Brix, specific gravity, and degrees Baumé of sugar solutions
|
|
|
|
Degrees Degrees
Brix or Brix Or
per- || Specific | Specific | Degrees per- Specific | Specific Degrees
cent- gravity gravity Baumé Cent- gravity gravity | Baumé
age of at at (modu- age of at. at (modu-
sucrose | 20°/4° C 20°/20° C. lus 145) || sucrose | 20°/4° C 20°/20° C. lus 145)
bv by
weight weight
(). () 0.998.23 | 1. 00000 (). 00 5. 0 | 1. 0.1785 | 1. 01965 2. W9
... 1 . 99862 | 1. 00039 . 06 5. 1 | 1. 01825 | 1. 02005 2. 85
... 2 . 99901 | 1. 00078 . 11 5. 2 | 1. 01865 | 1. 02045 2. 91
. 3 . 99940 | 1. 00117 17 5. 3 | 1. 01905 | 1. 02085 2. 96
. 4 . 99.979 | 1. 00155 22 5. 4 | 1. 01945 | 1. 02125 3. 02
5 | 1. 00017 | 1. 001.94 . 28 5. 5 | 1. 01985 | 1. 02165 3. 07
6 | 1. 00056 | 1. 00233 . 34 5. 6 | 1. 02025 | 1. 02206 3. 13
7 | 1. 00095 | 1. 00272 . 39 5. 7 | 1. 02065 | 1. 0.2246 3. 18
. 8 | 1. 00134 | 1. 00311 . 45 5. 8 | 1. 02105 | 1. 02286 3. 24
9 || 1. 001.73 | 1. 00350 . 51 5. 9 1. 02145 | 1. 02321 3. 30
1. 0 | 1. 00212 | 1. 0.0389 . 56 6. () | 1. 02186 | 1. 02366 3. 35
1. 1 | 1. 00251 | 1. OO428 . 62 6. 1 | 1. 02226 | 1. 02407 3. 41
| 2 | 1. 00290 | 1. 00467 . 67 6. 2 | 1. 02266 | 1. 02447 3. 46
1. 3 | 1. 00329 || 1. 00506 . 73 6. 3 | 1. 02306 | 1. 0.2487 3. 52
1. 4 || 1. 00368 | 1. 00545 ... 79 6. 4 || 1. 02346 | 1. 02527 3. 57
1, 5 | 1. 00406 | 1. 00584 . S4 6. 5 | 1. 02387 | 1. 02:568 3. 63
1. 6 | 1. 00445 1, 00623 . 90 6. 6 | 1. 02427 | 1. 02608 3. 69
1. 7 | 1. 0.0484 || 1. 0.0662 . 95 6. 7 | 1. 02467 | 1. 0.2648 3. 74
1. 8 || 1. 0.0523 | 1. 00701 1. 01 6. 8 | 1. 02508 || 1. 02689 3. 80
1. 9 || 1. 0.0562 | 1. 00740 1. 07 6. 9 || 1. 02548 | 1. 02729 3. 85
2. 0 | 1. 00602 | 1. 00779 1. 12 7. 0 | 1. 02588 | 1. 0.2770 3. 91
2. 1 | 1. 00641 | 1. O0818 1. 18 7. 1 | 1. 02629 | 1. 028.10 3. 96
2. 2 | 1. 00680 | 1. 00858 1. 23 7. 2 | 1. 02669 | 1. 02851 4. 02
2. 3 | 1. 00719 | 1. 00897 1. 29 7. 3 | 1. 02710 | 1. 02892 4. 08
2. 4 || 1. 00758 | 1. 0.0936 1. 34 7. 4 || 1. 0.2750 | 1. 02932 4. 13
2. 5 | 1. 00797 | 1. 0.0976 1. 40 7. 5 | 1. 02791 | 1. 02973 4. 19
2. 6 | 1. 00836 1. 0.1015 1. 46 7. 6 | 1. 02832 1. 03013 4. 24
2. 7 | 1. 00876 | 1. 0.1054 1. 5.1 7. 7 | 1. 02872 | 1. 03054 4. 30
2. 8 || 1. 00915 | 1. 01093 1. 57 7, 8 || 1. 02913 | 1. 03095 4. 35
2. 9 | 1. 0.0954 | 1. 0.1133 1. 62 7. 9 || 1. 02954 | 1. 03136 4. 41
3. 0 | 1. 00993 : 1. O1172 1. 68 8. 0 | 1. 02994 | 1. 03176 4. 46
3. 1 | 1. 01033 | 1. 01211 1. 74 8. 1 | 1. 03035 | 1. 03217 4. 52
3. 2 | 1. 0.1072 | 1. 01251 1. 79 8. 2 | 1. 03076 | 1. 03258 4. 58
3. 3 | 1. 01112 | 1. 01290 1. 85 8. 3 | 1. 03116 | 1. 03299 4. 63
3. 4 | 1. 01151 | 1. 01330 1. 90 8. 4 | 1. 03157 | 1. 0.3340 4. 69
3. 5 | 1. 01190 | 1. 0.1369 1. 96 8. 5 | 1. 03198 || 1. 03381 4. 74
3. 6 | 1. 01230 | 1. 01409 2. 02 8. 6 | 1. 03239 || 1. 03422 4. 80
3. 7 | 1. 01269 | 1. 0.1448 2. 07 8. 7 | 1. 03280 | 1. 03463 4. 85
3. 8 || 1. 0.1309 | 1. 0.1488 2. 13 8. 8 | 1. 03321 | 1. 03504 4. 91
3. 9 || 1. 01348 || 1. 01528 2. 18 8. 9 | 1. 03362 | 1. 03545 4. 96
4. 0 | 1. 01388 || 1. 0.1567 2. 24 9. 0 | 1. 03403 | 1. 03:586 5. 02
4. 1 | 1. 0.1428 | 1. 01607 2. 29 9. 1 | 1. 03444 | 1. 03627 5. 07
4, 2 | 1. 01467 | 1. 01647 2. 35 9. 2 | 1. 03485 | 1. 03668 5. 13
4. 3 | 1. 01507 | 1. 01687 2. 40 9. 3 | 1. 03526 1. 03709 5. 19
4. 4 | 1. 01547 | 1. 01726 2. 46 9. 4 | 1. 03567 | 1. 03750 5. 24
4. 5 | 1. 01586 | 1. 01766 2. 52 9. 5 | 1. 03608 | 1. 03792 5. 30
4. 6 | 1. 01626 | 1. 01806 2. 57 9. 6 | 1. 03649 | 1. 03833 5. 35
4. 7 | 1. 01666 | 1. 01846 2. 63 9. 7 | 1. 03691 | 1. 03874 5. 41
4. 8 || 1. 01706 | 1. 01886 2. 68 9. 8 | 1. O3732 | 1. 03915 5. 46
4. 9 | 1. 0.1746 | 1. 01926 2. 74 9. 9 | 1. 03773 | 1. 0.3957 5. 52
Polarimetry, Saccharimetry, and the Sugars
615
TABLE 109.- Degrees Bria!, specific gravity, and degrees Baumé of sugar solutions—
Continued
Degrees Degrees
Brix Or Brix or
per- Specific | Specific | Degrees per- Specific | Specific | Degrees
Cent- gravity gravity Baumé Cent- gravity gravity | Baumé
age of at, at (modu- age of at at (modu-
sucrose 20°/4° C 20°/20° C. lus 145) || sucrose | 20°/4° C 20°/20° C. lus 145)
by by
weight weight
10. 0 | 1. 03814 | 1. 03998 5. 57 15. 0 | 1. 0.5916 | 1. 06104 8. 34
10. 1 | 1. 03856 | 1. 04039 5. 63 15. 1 | 1. 05959 | 1. 061.47 8. 40
10. 2 | 1. 03897 | 1. 04081 5. 68 15. 2 | 1. 06002 | 1. 06190 8. 45
10. 3 | 1. 03938 | 1. 04122 5. 74 15. 3 | 1. 06045 | 1. 06233 8. 51
10. 4 | 1. 03980 | 1. 04164 5. 80 15. 4 | 1. 06088 | 1. 06276 8. 56
10. 5 | 1. 04021 | 1. 04205 5. 85 15. 5 | 1. 06131 | 1.06319 8. 62
10. 6 | 1. 04063 | 1. 04247 5. 91 15. 6 | 1. 06.174 | 1. 06362 8. 67
10. 7 | 1. 04104 | 1. 04288 5. 96 15. 7 | 1. 06217 | 1. 06405 8. 73
10.8 1.04146 | 1.04330 6. 02 15. 8 || 1. 06260 | 1. 06448 8. 78
10. 9 | 1. 04187 | 1. 04371 6. 07 15. 9 | 1. 06303 | 1. 06491 8. 84
11. 0 | 1. 04229 | 1. 04413 6. 13 16. 0 | 1.06346 | 1.06534 8. 89
11. 1 | 1. 042.70 | 1. 04455 6. 18 16. 1 | 1. 06389 | 1. 06577 8. 95
11. 2 | 1. 043.12 | 1. 04497 6. 24 16. 2 | 1. 06432 | 1. 06621 9. 00
11. 3 | 1. 04354 | 1. 04538 6. 30 16. 3 | 1. 06476 | 1. 06664 9. O6
11. 4 | 1. 04395 | 1. 04580 6. 35 16. 4 | 1. 06519 | 1. 06707 9. 11
11. 5 | 1. 04:437 | 1. 04622 6. 41 16. 5 | 1.06562 | 1. 06751 9. 17
11. 6 | 1. 04479 | 1. 04664 6. 46 16. 6 | 1. 06605 | 1. 06794 9. 22
11. 7 | 1. 04521 | 1. 04706 6. 52 16. 7 | 1. 06649 | 1. 06837 9. 28
11. 8 | 1. 04562 | 1. 04747 6. 57 16. 8 || 1. 06692 | 1. 06881 9. 33
11. 9 || 1. 04604 | 1. 04789 6. 63 16. 9 1. 06736 | 1. 06924 9. 39
12. 0 | 1. 04646 | 1. 04831 6. 68 17. 0 | 1. 06779 | 1. 06968 9. 45
12. 1 | 1. 04688 | 1. 04873 6. 74 17. 1 | 1. 06822 | 1. 07011 9. 50
12. 2 | 1. 04730 | 1. 04915 6. 79 17. 2 | 1. 06866 | 1. 0.7055 9. 56
12. 3 | 1. 04772 | 1. 04957 6. 85 17. 3 | 1. 06909 | 1. 07098 9. 61
12. 4 | 1.04814 | 1. 04999 6. 90 17. 4 | 1. 06953 | 1. 07142 9. 67
12. 5 | 1. 04856 | 1. 05041 6. 96 17. 5 | 1. 06996 | 1. 07186 9. 72
12. 6 | 1. 04898 | 1. 05084 7. 02 17. 6 | 1. 07040 | 1. 07229 9. 78
12. 7 | 1. 04940 | 1. 05126 7. 07 17. 7 | 1. 07084 || 1. 07273 9. 83
12. 8 | 1. 04982 | 1. 05168 7. 13 17. 8 1. 07127 | 1. 07317 9. 89
12. 9 | 1. 05024 | 1. 05210 7. 18 17. 9 || 1. 07171 | 1. 07361 9. 94
13. 0 | 1. 05066 | 1. 05252 7. 24 18. 0 | 1. 07215 | 1. 07404 10. 00
13. 1 | 1. 05109 | 1. 05295 7. 29 18. 1 | 1. 07258 | 1.07448 10. 05
13. 2 | 1. 05151 | 1. 05337 7. 35 18. 2 | 1. 07302 | 1. 07492 10. 11
13. 3 | 1. 05193 | 1. 05379 7. 40 18. 3 | 1. 07346 | 1. 07536 10. 16
13. 4 | 1. 05236 | 1. 05422 7. 46 18. 4 | 1. 07390 | 1. 07580 10. 22
13. 5 | 1. 05278 | 1. 0.5464 7. 51 18. 5 | 1. 07434 | 1. 07624 10. 27
13. 6 | 1. 05320 | 1. 05506 7. 57 18. 6 | 1. 07478 | 1. 07668 10. 33
13. 7 | 1. 05363 | 1. 05549 7. 62 18. 7 | 1. 07522 | 1. 07712 10. 38
13. 8 | 1. 05405 | 1. 0.5591 7. 68 18. 8 | 1. 07566 | 1. 077.56 10. 44
13. 9 | 1. 05448 | 1. 05634 7. 73 18, 9 || 1. 07610 | 1. 07800 10. 49
14. 0 | 1. 05490 | 1. 0.5677 7. 79 19. 0 | 1. 0.7654 | 1.07844 10. 55
14. 1 | 1. 05532 | 1. 05719 7. 84 19. 1 | 1. 07698 || 1. 07888 10. 60
14, 2 | 1. 05575 | 1.05762 7. 90 19. 2 | 1. 07742 | 1. 0.7932 10. 66
14. 3 | 1. 05618 | 1. 05804 7. 96 19. 3 | 1. 0.7786 | 1. 07977 10. 71
14. 4 | 1.05660 | 1.05847 8. 01 19. 4 | 1. 07830 | 1. 08021 10. 77
14. 5 | 1. 05703 | 1. 05890 8. 07 19. 5 | 1. 0.7874 | 1. 08065 10. 82
14. 6 | 1. 05746 | 1. 05933 8. 12 19. 6 | 1. 07919 1. 08110 10. 88
14, 7 | 1. 05788 | 1. 05975 8. 18 19. 7 | 1. 0.7963 | 1. 08154 10. 93
14. 8 1. 05831 | 1. 06018 8. 23 19. 8 | 1. 08007 | 1. 0.8198 10. 99
14, 9 | 1. 05874 | 1. 06061 8. 29 19. 9 | 1. 08052 | 1. 08243 11. 04
616
Circular of the National Bureau of Standards
TABLE 109.- Degrees Briz, specific gravity, and degrees Baumé of sugar solutions—
Continued
Degrees Degrees
Brix or Brix or
per- Specific | Specific | Degrees per- Specific | Specific | Degrees
cent- gravity gravity Baumé Cent- gravity gravity | Baumé
age of at at (modu- age of at at (modu-
sucrose | 20°/4° C 20°/20° C. lus 145) || sucrose | 20°/4° C | 20°/20° C. lus 145)
by by
weight weight
20. 0 | 1. 08096 | 1. 08287 11. 10 25. 0 | 1. 103.56 | 1. 10551 13. 84
20. I | 1. 08140 | 1. 08332 11. 15 25. 1 | 1. 10402 | 1. 10597 13. 89
20. 2 | 1. 08.185 | 1. 08376 11. 21 25. 2 | 1. 10448 | 1. 10643 13. 95
20. 3 | 1. 08229 | 1. 084.21 11. 26 25. 3 | 1. 10494 | 1. 10689 14. 00
20. 4 | 1. 08274 | 1.08465 11. 32 25. 4 | 1. 10540 | 1. 10736 14. 06
20. 5 | 1. 08318 | 1. 08510 11. 37 25. 5 | 1. 10586 | 1. 10782 14. 11
20. 6 | 1. 08363 | 1. 08554 11. 43 25. 6 | 1. 10632 | 1. 10828 14, 17
20. 7 | 1. 08407 | 1. 085.99 11. 48 25. 7 | 1. 10679 | 1. 10874 14, 22
20. 8 | 1. 08452 | 1. 0.8644 11. 54 25. 8 || 1. 10725 | 1. 10921 14, 28
20. 9 | 1. 08497 | 1. 08689 11. 59 25. 9 | 1. 10771 | 1. 10967 14. 33
21. 0 | 1. 08541 | 1. 08733 11. 65 26. 0 | 1. 10818 | 1. 11014 14. 39
21. 1 | 1. 08586 | 1. 08778 11. 70 26, 1 | 1. 10864 1, 11060 14. 44
21. 2 | 1. 08631 | 1. 08823 11. 76 26, 2 | 1. 10910 | 1. 11106 14. 49
21. 3 | 1. 08676 | 1. 08868 11. 81 26. 3 | 1. 10957 | 1. 11153 14. 55
21. 4 || 1. 08720 | 1. 08913 11. 87 26, 4 || 1. 11003 | 1. 11200 14. 60
21. 5 | 1. 08765 | 1. 08958 11. 92 26. 5 | 1. 11050 | 1. 11246 14, 66
21. 6 || 1. 08810 | 1. 09003 11. 98 26. 6 | 1. 11096 | 1. 11293 14. 71
21. 7 | 1. 08855 | 1. 09048 12. 03 26. 7 | 1. 11143 | 1. 11339 14. 77
21. 8 | 1. 08900 | 1. 09093 12. 09 26. 8 | 1. 11190 | 1. 11386 14. 82
21, 9 || 1. 08945 | 1. 091.38 12. 14 26. 9 | 1. 11236 | 1. 11433 14, 88
22. 0 | 1. 08990 | 1. 09183 12. 20 27. 0 | 1. 11283 | 1. 11480 14. 93
22. 1 | 1, 09035 | 1. 09.228 12. 25 27. 1 | 1. 11330 | 1. 11526 14. 99
22. 2 | 1. 09080 | 1. 09:273 12. 31 27. 2 | 1. 11376 | 1. 11573 15. 04
22. 3 | 1. 09.125 | 1. 093.18 12. 36 27. 3 | 1. 11423 | 1. 11620 15. 09
22. 4 | 1. 09.170 | 1. 09364 12. 42 27. 4 || 1. 11470 | 1. 11667 15. 15
22. 5 | 1. 09.216 | 1. 09.409 12. 47 27. 5 | 1. 11517 | 1. 11714 15. 20
22. 6 | 1. 09.261 | 1. 0945.4 12. 52 27. 6 | 1. 11564 | 1. 11761 15. 26
22. 7 | 1. 09306 | 1.09499 12. 58 27, 7 | 1. 11610 | 1. 11808 15. 31
22. 8 | 1. 09351 | 1. 0.9545 12. 63 27. 8 || 1. 11657 | 1. 11855 15. 37
22, 9 || 1. 09397 | 1. 09590 12. 69 27, 9 | 1. 11704 | 1. 11902 15. 42
23. 0 | 1. 09442 | 1. 09636 12. 74 28, 0 | 1. 11751 | 1. 11949 15. 48
23. 1 | 1. 09487 | 1. 09681 12. 80 28. 1 | 1. 11798 || 1. 11996 15. 53
23. 2 | 1,09533 | 1.09727 12. 85 28. 2 | 1. 11845 | 1. 12043 15. 59
23. 3 | 1. 09578 || 1. 09772 12, 91 28. 3 | 1. 11892 | 1. 12090 15. 64
23. 4 | 1. 09624 | 1. 098.18 12, 96 28. 4 || 1. 11940 | 1. 12138 15. 69
23. 5 | 1. 09669 | 1. 09863 13. 02 28, 5 | 1. 11987 | 1. 12.185 15. 75
23. 6 | 1. 097.15 | 1. 09909 13. 07 28. 6 | 1. 12034 | 1. 12232 15. 80
23. 7 | 1. 09760 | 1. 09954 13. 13 28. 7 | 1. 12081 | 1. 12280 15. 86
23. 8 | 1. 09806 | 1. 10000 13. 18 28. 8 | 1. 12128 | 1. 12327 15. 91
23. 9 | 1. 09851 | 1. 10046 13. 24 28, 9 || 1. 12176 | 1. 12374 15. 97
24. 0 | 1. 09897 | 1. 10092 13. 29 29. 0 | 1. 12223 | 1. 12422 16. 02
24. 1 | 1. 09943 | 1. 10137 13. 35 29. 1 | 1. 12270 | 1. 12469 16. 08
24, 2 | 1. 09989 | 1. 10183 13. 40 29. 2 | 1. 12318 | 1. 1251.7 16. 13
24, 3 | 1. 10034 | 1. 10229 13. 46 29, 3 | 1. 12365 | 1. 12564 16. 18
24. 4 | 1. 10080 | 1. 10275 13. 51 29. 4 | 1. 12413 | 1. 12612 16. 24
24. 5 | 1. 10.126 | 1. 10321 13. 57 29. 5 | 1. 12460 | 1. 12659 16. 29
24. 6 | 1. 10172 | 1. 10367 13. 62 29. 6 | 1. 12508 | 1. 12707 16. 35
24. 7 | 1. 10218 | 1. 10413 13. 67 29. 7 | 1. 12556 | 1. 12755 16. 40
24. 8 | 1. 10264. | 1. 10459 13. 73 29, 8 || 1. 12603 | 1. 12802 16. 46
24, 9 | 1. 10310 | 1. 10505 13. 78 29. 9 | 1. 12651 | 1. 12850 16. 51
Polarimetry, Saccharimetry, and the Sugars
617
TABLE 109.- Degrees Bria, specific gravity, and degrees Baumé of sugar solutions—
Continued
Degrees Degrees
Brix or Brix Or
per- || Specific | Specific | Degrees per- Specific | Specific | Degrees
cent- gravity gravity | Baumé Cent- gravity gravity | Baumé
age of at: at (modu- age of at at (modu-
suº 20°/4° C 20°/20° C. lus 145) || sucrose | 20°/4° C 20°/20° C. lus 145)
y by
weight weight
30, 0 | 1. 12698 || 1. 12898 16. 57 35. 0 | 1. 15128 1. 15331 19. 28
30. 1 | 1. 12746 | 1. 12946 16. 62 35. 1 | 1. 15177 | 1. 15381 19. 33
30. 2 | 1. 12794 | 1. 12993 16. 67 35. 2 | 1. 15226 | 1. 15430 19. 38
30, 3 | 1. 12842 | 1. 13041 16. 73 35. 3 | 1. 15276 | 1. 15480 19. 44
30. 4 | 1. 12890 | 1. 13089 16. 78 35. 4 || 1. 15326 | 1. 15530 19. 49
30. 5 | 1. 12937 | 1. 13137 16. 84 35. 5 | 1. 15375 | 1. 15579 19. 55
30. 6 | 1. 12985 | 1. 1318.5 16. 89 35. 6 | 1. 15425 | 1. 15629 19. 60
30. 7 | 1. 13033 | 1. 13233 16. 95 35. 7 | 1. 15475 | 1. 15679 19, 65
30, 8 || 1. 13081 | 1. 13281 17. 00 35. 8 || 1. 15524 | 1. 15729 19, 71
30. 9 | 1. 13129 | 1. 13329 17. 05 35. 9 | 1. 15574 1. 15778 19. 76
31. 0 | 1. 13177 | 1. 13378 17, 11 36. 0 | 1. 15624 | 1. 15828 19. 81
31. 1 | 1. 13225 | 1. 13426 17. 16 36. 1 | 1. 15674 | 1. 15878 19. 87
31. 2 | 1. 13274 | 1. 13474 17. 22 36. 2 | 1. 15724 | 1. 15928 19. 92
31. 3 | 1. 13322 | 1. 13522 17, 27 36. 3 | 1. 15773 | 1. 15978 19. 98
31. 4 | 1. 13370 | 1. 13570 17. 33 36. 4 | 1. 15823 | 1. 16028 20. 03
31. 5 | 1. 13418 | 1. 13619 17. 38 36. 5 | 1. 15873 | 1. 16078 20. 08
31. 6 | 1. 13466 | 1. 13667 17. 43 36. 6 | 1. 15923 | 1. 16128 20. 14
31. 7 | 1. 13515 | 1. 13715 17. 49 36. 7 | 1. 15973 | 1. 16178 20. 19
31. 8 | 1. 13563 | 1. 13764 17. 54 36. 8 || 1. 16023 | 1. 16228 20. 25
31. 9 | 1. 13611 | 1. 13812 17. 60 36. 9 || 1. 16073 | 1. 16279 20. 30
32. 0 | 1. 13660 | 1. 13861 17. 65 37. 0 | 1. 16124 | 1. 16329 20. 35
32. 1 | 1. 13708 || 1. 13909 17, 70 37. 1 | 1. 16174 | 1. 16379 20. 41
32. 2 | 1. 13756 | 1. 13958 17, 76 37. 2 | 1. 16224 | 1. 16430 20. 46
32. 3 | 1. 13805 | 1. 14006 17. 81 37. 3 | 1. 16274 | 1. 16480 20. 52
32. 4 | 1. 13853 | 1. 14055 17. 87 37. 4 | 1. 16324 | 1. 16530 20. 57
32. 5 | 1. 13902 | 1. 14103 17. 92 37. 5 | 1. 16375 | 1. 16581 20. 62
32. 6 1, 13951 | 1. 141 52 17. 98 37. 6 | 1. 16425 | 1. 16631 20. 68
32. 7 | 1. 13999 || 1. 1420.1 18. 03 37. 7 | 1. 16476 | 1. 16682 20. 73
32. 8 | 1. 14048 | 1. 14250 18. 08 37, 8 1, 16526 1. 16732 20. 78
32. 9 || 1. 14097 | 1. 14298 18. 14 37. 9 || 1. 16576 | 1. 16783 20. 84
33. 0 | 1. 14145 | 1. 14347 18. 19 38. 0 | 1. 16627 | 1. 16833 20. 89
33. 1 | 1. 14194 | 1. 14396 18. 25 38. 1 | 1. 16678 | 1. 16884 20. 94
33. 2 | 1. 14243 | 1. 14445 18. 30 38. 2 | 1, 16728 | 1. 16934 21, 00
33. 3 | 1. 14292 | 1. 14494 18. 36 38. 3 | 1. 16779 | 1. 16985 21, 0:5
33. 4 || 1. 14340 | 1. 14543 18. 41 38. 4 | 1. 16829 | 1. 17036 21. 11
33. 5 | 1. 14389 | 1. 14592 18. 46 38. 5 | 1. 16880 | 1. 17087 21. 16
33. 6 | 1. 14438 | 1. 14641 18, 52 38. 6 | 1. 16931 | 1. 17138 21. 21
33. 7 | 1. 14487 | 1. 14690 18. 57 38. 7 | 1. 16982 | 1. 17188 21. 27
33. 8 || 1. 14536 | 1. 14739 18. 63 38. 8 || 1. 17032 | 1. 17239 21. 32
33. 9 | 1. 14585 | 1. 14788 18, 68 38. 9 || 1, 17083 | 1. 17290 21. 38
34 0 | 1. 14634 | 1. 14837 18. 73 39. 0 | 1. 17134 | 1. 17341 21. 43
34. 1 | 1. 14684 | 1. 14886 18. 79 39. 1 | 1. 17185 | 1. 17392 21. 48
34. 2 | 1. 14733 | 1. 14936 18. 84 39. 2 | 1. 17236 | 1. 17443 21. 54
34. 3 | 1. 14782 | 1. 14985 18. 90 39. 3 | 1. 17287 | 1. 17494 21, 59
34, 4 || 1. 14831 | 1. 15034 18. 95 39. 4 || 1. 17338 | 1. 17545 21. 64
34. 5 | 1. 14880 | 1, 15084 19. 00 39, 5 1, 17389 | 1. 17596 21. 70
34. 6 | 1. 14930 | 1. 15133 19. 06 39. 6 | 1. 17440 | 1. 17648 21. 75
34. 7 | 1. 14979 | 1. 15183 19. 11 39. 7 | 1. 17491 | 1. 17699 21. 80
34, 8 || 1. 15029 | 1. 15232 19. 17 39. 8 || 1. 17542 | 1. 17750 21. 86
34.9 | 1. 15078 | 1. 15282 19. 22 39. 9 | 1. 17594 | 1. 17802 21. 91
618
Circular of the National Bureau of Standards
TABLE 109.- Degrees Bria!, specific gravity, and degrees Baumé of sugar solutions—
Continued
Degrees Degrees
Brix Or Brix Or
per- Specific Specific | Degrees per- Specific | Specific Degrees
cent- gravity gravity Baumé Cent- gravity gravity Baumé
age of at: at (modu- age of at, at (modu-
sucrose | 20°/4° C 20°/20° C. lus 145) || sucrose | 20°/4° C 20°/20° C. lus 145)
by by
weight weight
40. 0 | 1. 17645 1, 17853 21.97 45. 0 | 1. 20254 | 1. 20467 24. 63
40. 1 | 1. 17696 | 1. 17904 22. 02 45. 1 | 1. 20307 | 1. 20520 24. 69
40. 2 | 1. 17747 | 1. 17956 22. 07 45. 2 | 1. 20360 | 1. 20573 24. 74
40. 3 | 1. 17799 || 1. 18007 22. 13 45. 3 | 1. 20414 | 1. 20627 24. 79
40. 4 | 1. 17850 | 1. 18058 22. 18 45. 4 | 1. 20467 | 1. 20680 24. 85
40. 5 | 1. 17901 | 1. 18110 22. 23 45. 5 | 1. 20520 | 1. 20733 24. 90
40. 6 | 1. 17953 | 1, 18162 22, 29 45.6 | 1. 20573 | 1. 20787 24. 95
40. 7 | 1. 18004 || 1. 18213 22. 34 45. 7 | 1. 20627 | 1. 20840 25. 01
40. 8 || 1. 18056 | 1, 18265 22. 39 45. 8 | 1. 20680 | 1. 20894 25. 06
40. 9 | 1. 18108 || 1. 18316 22. 45 45. 9 | 1. 20734 | 1. 20947 25. 11
41. 0 | 1. 18159 | 1, 18368 22. 50 46. 0 | 1. 20787 | 1. 21001 25. 1 7
4.1. 1 | 1. 18211 | 1. 18420 22. 55 46. 1 | 1. 20840 | 1. 21054 25. 22
41. 2 | 1. 18262 | 1. 18472 22. 61 46. 2 | 1. 20894 | 1. 21108 25. 27
41. 3 | 1. 18314 | 1. 18524 22. 66 46. 3 | 1. 20948 | 1. 21162 25. 32
41. 4 || 1. 18366 | 1. 18575 22. 72 46. 4 | 1. 21001 | 1. 21215 25. 38
41. 5 | 1. 18418 | 1. 18627 22. 77 46. 5 | 1. 21055 | 1. 21269 25. 43
41. 6 | 1. 18470 | 1. 18679 22. 82 46. 6 | 1. 21109 | 1. 21323 25. 48
41. 7 | 1. 18522 | 1. 18731 22. 88 46. 7 | 1. 21162 | 1. 21377 25. 54
4.1. 8 || 1. 18573 1, 18783 22. 93 46. 8 | 1. 21216 | 1. 21431 25. 59
41. 9 | 1. 18625 | 1. 18835 22. 98 46. 9 | 1. 21270 | 1. 21484 25. 64
42. 0 | 1. 18677 | 1. 18887 23. 04 47. 0 | 1. 21324 | 1. 21.538 25. 70
42. 1 | 1. 18729 || 1, 18939 23. 09 47. 1 | 1. 21378 | 1. 21592 25. 75
42. 2 | 1. 18781 | 1. 18992 23. 14 47. 2 | 1. 21432 | 1. 21646 25. 80
42. 3 | 1. 18834 | 1. 19044 23. 20 47. 3 | 1. 21486 || 1. 21 700 25. 86
42. 4 || 1, 18886 | 1. 19096 23. 25 47. 4 | 1. 21540 | 1. 21755 25. 91
42. 5 | 1, 18938 | 1. 19148 23. 30 47. 5 | 1. 21594 | 1. 21809 25. 96
42. 6 | 1. 18990 | 1. 1920.1 23. 36 47. 6 | 1. 21648 || 1. 21863 26. 01
42. 7 | 1. 19042 | 1. 19253 23. 41 47. 7 | 1. 21702 | 1. 21917 26. 07
42. 8 || 1. 19095 | 1, 19305 23. 46 47. 8 || 1. 21756 | 1. 21971 26. 12
42. 9 || 1. 19147 | 1. 19358 23. 52 47. 9 | 1. 21810 | 1. 22026 26. 1 7
43. 0 | 1. 1919.9 | 1. 19410 23. 57 48. 0 | 1. 21864 | 1. 22080 26. 23
43. 1 | 1. 19252 | 1. 19463 23. 62 48. I | 1. 21918 | 1. 22134 26. 28
43. 2 | 1. 19304 | 1. 19515 23. 68 48. 2 | 1. 21973 | 1. 22.189 26. 33
43. 3 | 1. 19356 | 1. 19568 23. 73 48. 3 | 1.22027 | 1. 22243 26. 38
43. 4 || 1. 19409 | 1. 19620 23. 78 48. 4 | 1. 22082 | 1. 22.298 26. 44
43. 5 | 1. 19462 | 1. 19673 23. 84 48. 5 | 1. 22136 | 1. 22352 26. 49
43. 6 | 1. 19514 | 1. 19726 23. 89 48. 6 | 1. 22190 | 1. 22406 26. 54
43. 7 | 1. 19567 | 1. 19778 23. 94 48. 7 | 1. 22.245 | 1. 22461 26. 59
43. 8 || 1. 19619 | 1. 19831 24. 00 48. 8 | 1. 22300 | 1. 22516 26. 65
43. 9 | 1. 19672 | 1. 19884 24. 05 48. 9 | 1. 22354 | 1. 22570 26. 70
44. 0 | 1. 19725 | 1. 19936 24. 10 49. 0 | 1, 22409 | 1. 22625 26. 75
44. 1 | 1. 19778 1. 19989 24. 16 49. 1 | 1. 22463 | 1. 22680 26. 81
44, 2 | 1. 19830 | 1. 20042 24, 21 49. 2 | 1. 22518 | 1. 22735 26. 86
44. 3 | 1. 19883 | 1. 20095 24, 26 49. 3 | 1. 22573 | 1. 22789 26. 91
44. 4 | 1. 19936 | 1. 20148 24, 32 49. 4 | 1. 22627 | 1. 22844 26. 96
44, 5 | 1. 19989 | 1. 2020.1 24. 37 49. 5 | 1. 22682 | 1. 22899 27. ()2
44, 6 | 1. 20042 | 1. 20254 24. 42 49. 6 | 1. 22737 | 1. 22954 27. 07
44. 7 | 1. 20095 | 1. 20307 24. 48 49. 7 | 1. 22792 | 1. 23009 27. 12
44, 8 | 1. 20148 | 1. 20360 24. 53 49. 8 || 1. 22847 | 1. 23064 27. 18
44. 9 | 1. 20201 | 1. 20414 24. 58 49. 9 || 1. 22902 | 1. 23119 27. 23
Polarimetry, Saccharimetry, and the Sugars
619
TABLE 109.- Degrees Bria!, specific gravity, and degrees Baumé of sugar solutions—
Continued
Degrees
Brix Or
per- Specific | Specific
cent- gravity gravity
age of at at
sucrose | 20°/4° C 20°/20°C
y
weight
50. 0 | 1. 22957 | 1. 23174
50. 1 | 1. 23012 | 1. 23229
50. 2 | 1. 23067 | 1. 23284
50. 3 | 1. 23122 | 1. 23340
50. 4 || 1. 23177 | 1. 23395
50. 5 | 1. 23232 | 1. 23450
50. 6 | 1. 23.287 | 1. 23506
50. 7 | 1. 23343 | 1. 23561
50. 8 || 1. 23398 | 1. 23616
50. 9 || 1. 23453 | 1. 23672
51. 0 | 1. 23508 | 1. 23727
51. 1 | 1. 23564 | 1. 23782
51. 2 | 1. 23619 | 1. 23838
51. 3 | 1. 23675 | 1. 23894
51. 4 || 1. 23730 | 1. 23949
51. 5 | 1. 23786 | 1. 24005
51. 6 | 1. 23841 | 1. 24060
51. 7 | 1. 23897 | 1. 241 16
51.8 | 1. 23953 1, 24172
51. 9 1, 24008 || 1. 24.228
52. 0 | 1. 24064 | 1. 24284
52. 1 | 1. 24.120 | 1. 24339
52. 2 | 1. 24.176 | 1. 24395
52. 3 | 1. 24232 | 1. 24451
52. 4 | 1. 24287 | 1. 34507
52. 5 | 1. 24343 | 1. 24.563
5.2. 6 1. 24399 || 1. 24619
52. 7 | 1. 24455 | 1. 24.675
52, 8 || 1. 2451 1 | 1. 24731
52. 9 | 1. 24567 | 1. 24788
53. 0 | 1. 24623 | 1. 24844
53. 1 | 1. 24680 | 1. 24900
53. 2 | 1. 24736 | 1. 24956
53. 3 | 1. 24792 | 1. 25013
53. 4 | 1. 24848 | 1. 25069
53. 5 | 1. 24.905 | 1. 25.126
53. 6 | 1. 24961 | 1. 25.182
53. 7 | 1. 25017 | 1. 25238
53. 8 || 1. 25074 | 1. 25295
53. 9 || 1. 25130 | 1. 25.351
54. 0 | 1. 25.187 | 1. 25408
54. 1 | 1. 25243 | 1. 25465
54. 2 | 1. 25300 | 1. 25521
54. 3 | 1. 25356 | 1. 25578
54. 4 | 1. 25413 | 1. 25635
54. 5 | 1. 254.70 | 1. 25692
54. 6 | 1. 25526 | 1. 25748
54. 7 | 1. 25583 | 1. 25805
54. 8 || 1. 25640 | 1. 25862
54 g | 1.25697 i. 25919
Degrees
Brix Or
Degrees per- Specific | Specific | Degrees
Baumé Cent- gravity gravity | Baumé
(modu- age of at at (modu-
lus 145) || sucrose | 20°/4° C 20°/20° C. lus 145)
by
weight
27, 28 55. 0 | 1. 25754 | 1. 25976 29. 90
27. 33 55. 1 | 1. 25.810 | 1. 26033 29. 95
27. 39 55. 2 | 1. 25867 | 1. 26090 30, 00
27. 44 55. 3 | 1. 25924 | 1. 26147 30. 06
27. 49 55. 4 || 1. 25982 | 1. 26.204 30. 11
27. 54 55. 5 | 1. 26039 || 1. 26261 30. 16
27. 60 55. 6 | 1. 26096 || 1. 26319 30, 21
27. 65 55. 7 | 1. 26.153 | 1. 26376 30, 26
27, 70 55. 8 | 1. 26210 | 1. 26433 30. 32
27, 75 55. 9 || 1. 26.267 | 1. 26490 30. 37
27. 81 56. 0 | 1. 26324 | 1. 26548 30. 42
27. 86 56. 1 | 1. 26382 | 1. 26605 30, 47
27. 91 56. 2 | 1. 26439 | 1. 26663 30. 52
27. 96 56. 3 | 1. 26496 || 1. 26720 30. 57
28. 02 56.4 | 1. 26554 | 1. 26778 30. 63
28. 07 56. 5 | 1. 26611 | 1. 26835 30. 68
28. 12 56. 6 | 1. 26669 | 1. 26893 30. 73
28. 17 56. 7 | 1. 26726 | 1. 26950 30. 78
28, 23 56. 8 | 1. 26784 | 1. 27008 30. 83
28, 28 56, 9 | 1. 2684.1 | 1. 27066 30.89
28. 33 57. 0 | 1. 26899 || 1. 27.123 30. 94
28. 38 57. 1 | 1. 26956 | 1. 27181 30. 99
28. 44 57. 2 | 1. 27014 | 1. 27239 31. 04
28. 49 57. 3 | 1. 27072 | 1. 27297 31. 09
28, 54 57. 4 || 1. 27.130 | 1. 27355 31. 15
28. 59 57. 5 1. 27.188 | 1. 274.13 31. 20
28. 65 57. 6 | 1. 27246 | 1. 274.71 31. 25
28. 70 57. 7 | 1. 27.304 | 1. 27.529 31. 30
28. 75 57. 8 || 1. 27361 | 1. 27.587 31. 35
28. 80 57. 9 1. 27419 | 1. 27645 31. 40
28. 86 58. O | 1. 274.77 | 1. 27703 31. 46
28. 91 58. 1 | 1. 27.535 | 1. 27761 31. 51
28. 96 58. 2 | 1. 27594 | 1. 278.19 31. 56
29. 01 58. 3 | 1. 27652 | 1. 27878 31. 61
29. 06 58. 4 | 1. 27710 | 1. 27.936 31. 66
29. 12 58. 5 | 1. 27768 | 1. 27994 31. 71
29, 17 58. 6 | 1. 27826 | 1. 28052 31. 76
29. 22 58. 7 | 1. 27884 | 1. 28111 31. 82
29. 27 58. 8 || 1. 27943 | 1. 28169 31. 87
29. 32 58. 9 || 1. 28001 | 1. 28228 31. 92
29. 38 59. 0 | 1. 28060 | 1. 28286 31. 97
29. 43 59. 1 | 1. 28118 | 1. 28345 32. 02
29. 48 59. 2 | 1. 28.176 | 1. 28.404 32. 07
29. 53 59. 3 | 1. 28.235 | 1. 28462 32. 13
29. 59 59. 4 | 1. 28294 | 1. 28520 32. 18
29. 64 59. 5 | 1. 28352 | 1. 28579 32. 23
29. 69 59. 6 | 1. 284.11 | 1. 28638 32. 28
29. 74 59. 7 | 1. 28469 | 1. 28697 32. 33
29, 80 59. 8 || 1. 28528 || 1. 28755 32. 38
29. 85 || 59.9 | 1. 28587 | 1. 28814 32. 43
620 Circular of the National Bureau of Standards
TABLE 109.- Degrees Bria!, specific gravity, and degrees Baumé of sugar solutions—
Continued
Degrees Degrees
Brix or Brix or
per- Specific | Specific | Degrees per- Specific | Specific | Degrees
cent- gravity gravity | Baumé cent- gravity gravity | Baumé
age of at at (modu- age of at at (modu-
sugge 20°/4° C 20°/20° C. lus 145) || sucrose | 20°/4° C 20°/20° C. lus 145)
y by
weight weight
60. 0 | 1. 28646 | 1. 28873 32, 49 65. 0 | 1. 31633 | 1. 31866 35. 04
60. 1 | 1. 28704 | 1. 28932 32, 54 65. 1 | 1.31694 | 1. 31927 35. 09
60. 2 | 1. 28763 | 1. 2899.1 32. 59 65. 2 | 1.31755 | 1. 31988 35. 14
60. 3 | 1. 28822 | 1. 29050 32. 64 65. 3 | 1. 31816 | 1. 32049 35. 19
60. 4 | 1. 28881 | 1. 29.109 32. 69 65. 4 | 1. 31877 | 1. 32110 35. 24
60. 5 | 1. 28940 | 1. 29168 32. 74 65. 5 | 1. 31937 | 1. 32171 35. 29
60. 6 | 1. 28.999 || 1. 29.227 32. 79 65. 6 | 1. 31998 || 1. 32232 35. 34
60. 7 | 1. 29058 | 1. 29.286 32. 85 65. 7 | 1. 32059 | 1. 32.293 35. 39
60. 8 | 1. 29.117 | 1. 29346 32. 90 65. 8 1. 32120 | 1. 32354 35. 4.5
60. 9 1. 29176 | 1. 29.405 32. 95 65. 9 | 1. 32.181 | 1. 324.15 35. 50
61. 0 | 1. 29235 | 1. 29.464 33. 00 66. 0 | 1. 32242 1. 32476 35. 55
61. 1 | 1. 29.295 | 1. 29523 33. 05 66. 1 | 1. 32304 || 1. 32538 35. 60
61. 2 | 1. 29354 | 1. 29.583 33. 10 66. 2 | 1. 32365 | 1. 32599 35. 65
61. 3 | 1. 294.13 | 1. 29642 33. 15 66. 3 | 1. 32426 | 1. 32660 35. 70
61. 4 | 1. 29472 | 1. 29.701 33. 20 66. 4 || 1. 32487 | 1. 32722 35. 75
61. 5 | 1. 29.532 | 1. 29761 33. 26 66. 5 | 1. 32548 || 1. 32783 35. 80
61. 6 | 1. 29.591 | 1. 29.820 33. 31 66. 6 | 1. 32610 | 1. 32844 35. 85
61. 7 | 1. 296.51 | 1. 29.880 33. 36 66. 7 | 1. 32671 | 1. 32906 35. 90
61. 8 || 1. 29710 | 1. 29940 33. 41 66. 8 || 1. 32732 | 1. 32967 35. 95
61. 9 || 1. 297.70 | 1. 29.999 33. 46 66. 9 || 1. 32.794 | 1. 33029 36. 00
62. 0 | 1. 298.29 | 1. 30059 33. 5.1 67. 0 | 1. 32855 | 1. 33090 36. 05
62. 1 | 1. 29.889 | 1. 30.118 33. 56 67. 1 | 1. 32917 | 1. 33.15.2 36. 10
62. 2 | 1. 29948 || 1. 301.78 33. 6] 67. 2 | 1. 32978 | 1. 33214 36. 15
62. 3 | 1. 30008 || 1. 30238 33. 67 67. 3 | 1. 33040 | 1. 33275 36. 20
62. 4 | 1.30068 1, 30298 33. 72 67. 4 | 1. 33102 | 1.33337 36. 25
62. 5 | 1. 30127 | 1. 30358 33. 77 67. 5 | 1. 33.163 | 1. 33.399 36. 30
62. 6 | 1. 30187 | 1. 30418 33. 82 67. 6 | 1. 33225 | 1. 33460 36. 35
62. 7 | 1. 30247 | 1. 30477 33. 87 67. 7 | 1. 33287 | 1. 33523 36. 40
62. 8 | 1. 30307 | 1. 30537 33. 92 67. 8 | 1. 33348 | 1. 33584 36. 45
62. 9 | 1. 30367 | 1. 30597 33. 97 67. 9 | 1. 33410 | 1. 33646 36. 50
63. 0 | 1. 30427 | 1. 30657 34. 02 68. 0 | 1. 33472 | 1. 33708 36. 55
63. 1 | 1. 30487 | 1. 30718 34. 07 68. 1 | 1. 33534 1. 33770 36. 61
63. 2 | 1. 30547 | 1. 30778 34. 12 68. 2 | 1. 33596 || 1. 33832 36. 66
63. 3 | 1. 30607 | 1. 30838 34. 18 68. 3 | 1. 33658 | 1. 33894 36. 71
63. 4 || 1. 30667 | 1. 30898 34. 23 68. 4 | 1.33720 | 1. 339.57 36. 76
63. 5 | 1. 30727 | 1. 30958 34. 28 68. 5 1, 33782 | 1. 34019 36. 81
63. 6 1. 30787 | 1. 31019 34, 33 68. 6 | 1. 33844 | 1. 34081 36. 86
63. 7 | 1. 30848 | 1. 31079 34. 38 68. 7 | 1. 33906 | 1. 34143 36. 91
63. 8 || 1. 30908 || 1. 31139 34. 43 68. 8 || 1. 33968 1. 34.205 36. 96
63. 9 | 1. 30968 || 1. 31200 34. 48 68. 9 | 1. 34031 | 1. 34268 37. 01
64. 0 | 1. 31028 | 1. 31260 34. 53 69. 0 | 1. 34093 | 1. 34330 37. 06
64. 1 | 1. 31088 || 1 .31320 34. 58 69. 1 | 1. 34155 | 1. 34392 37. 11
64. 2 | 1. 31149 | 1. 31381 34, 63 69. 2 | 1. 34217 | 1. 34455 37. 16
64. 3 | 1, 31209 | 1.31441 34. 68 69. 3 | 1.34280 | 1. 34517 37. 21
64. 4 | 1. 31270 | 1. 31.502 34. 74 69. 4 || 1, 34342 | 1.34580 37. 26
64. 5 | 1. 31330 | 1. 31.563 34. 79 69. 5 | 1. 34.405 | 1. 34642 37. 31
64. 6 | 1. 31391 | 1. 31623 34. 84 69. 6 1, 34467 | 1. 34705 || 37. 36
64. 7 | 1. 31452 | 1. 31684 34. 89 69. 7 | 1. 34530 | 1. 34768 37. 41
64. 8 | 1. 31512 | 1. 31745 34. 94 69. 8 || 1, 34592 | 1. 34830 37. 46
64. 9 | 1. 31.573 | 1. 31806 34, 99 69, 9 || 1, 34655 | 1. 34893 37. 51
Polarimetry, Saccharimetry, and the Sugars
621
TABLE 109.- Degrees Bria, specific gravity, and degrees Baumé of sugar solutions—
Continued
Degrees Degrees
Brix Or Brix Or
per- Specific | Specific | Degrees per- Specific | Specific | Degrees
cent- gravity gravity Baumé Cent- gravity gravity | Baumé
age of at at, (modu- age of at, at, (modu-
sº 20°/4° C 20°/20° C. lus 145) || Sucrose | 20°/4° C 20°/20° C. lus 145)
y by
weight weight
70. 0 | 1. 34717 | 1. 34956 37. 56 75. 0 | 1. 37897 | 1. 38.141 40. 03
70. 1 | 1. 34780 | 1. 35019 37. 61 75. 1 | 1. 37962 | 1. 38206 40. 08
70. 2 | 1. 34843 | 1. 35081 37, 66 75. 2 | 1. 38026 | 1. 38270 40. 13
70. 3 | 1. 34906 | 1. 35144 37. 71 75. 3 | 1. 38091 | 1. 38335 40. 18
70. 4 | 1. 34968 | 1. 35207 37. 76 75. 4 || 1. 38156 | 1. 38400 40. 23
70. 5 | 1. 35031 | 1. 35270 37. 81 75. 5 | 1. 38220 | 1. 38465 40. 28
70. 6 | 1. 35094 | 1. 35333 37. 86 75. 6 | 1. 38285 | 1. 38530 40. 33
70. 7 | 1. 351.57 | 1. 35396 || 37. 91 75. 7 | 1. 38.350 | 1. 38595 40. 38
70, 8 || 1. 35220 | 1. 35459 37. 96 75. 8 || 1. 38415 | 1. 38660 40. 43
70. 9 || 1. 35283 | 1. 35522 38. 01 75. 9 || 1. 38480 | 1. 38725 40. 48
71. 0 | 1. 35346 | 1. 35585 38. 06 76. 0 | 1. 38545 | 1. 38790 40. 53
71. 1 | 1. 35409 | 1. 35648 38. 11 76. 1 | 1. 38610 | 1. 38855 40. 57
71. 2 | 1. 35472 | 1. 35.711 38. 16 76. 2 | 1. 38675 | 1. 38920 40, 62
71. 3 | 1. 35.535 | 1. 35775 38. 21 76. 3 | 1. 38740 | 1. 38985 40. 67
71. 4 | 1. 35598 || 1. 35838 38. 26 76. 4 || 1. 38805 | 1. 39050 40. 72
71. 5 | 1. 35661 | 1. 35901 38. 30 76. 5 | 1. 38870 | 1. 39115 40. 77
71. 6 | 1. 35724 | 1. 35964 38. 35 76. 6 | 1. 38935 | 1. 39180 40. 82
71. 7 | 1. 35788 || 1. 36028 38. 40 76. 7 | 1. 39000 | 1. 39246. 40. 87
71. 8 | 1. 35851 | 1.36091 38. 45 76. 8 | 1. 39065 | 1. 39311 40. 92
71. 9 || 1. 35914 | 1. 36155 38. 50 76. 9 | 1. 39.130 | 1. 39376 40. 97
72. 0 | 1. 35978 | 1. 36.218 38. 55 77. 0 | 1. 39.196 | 1. 39442 41. 01
72. 1 | 1. 36041 | 1. 36282 38. 60 77. 1 | 1. 39261 | 1. 39507 41. 06
72. 2 | 1. 36105 | 1. 36346 38. 65 77. 2 | 1. 39326 | 1. 39573 4.1. 11
72. 3 | 1. 36.168 | 1. 36409 38. 70 77. 3 | 1. 39392 | 1. 39638 41. 16
72. 4 | 1. 36.232 | 1. 36473 38. 75 77. 4 | 1. 394.57 | 1. 39704 41. 21
72. 5 | 1. 36295 | 1. 36536 38. 80 77. 5 | 1. 39523 | 1. 39769 41. 26
7.2. 6 | 1. 36359 | 1. 36600 38. 85 77. 6 | 1. 395.88 1. 39.835 41. 31
72. 7 | 1. 36423 | 1. 36664 38. 90 77. 7 | 1. 39654 | 1. 39901 41. 36
72. 8 | 1. 36486 | 1. 36728 38. 95 77. 8 || 1. 39719 | 1. 39.966 41. 40
72. 9 | 1. 36550 | 1. 36792 39. 00 77. 9 || 1. 39785 | 1. 40032 41. 45
73. 0 | 1. 36614 | 1. 36856 39. 05 78. 0 | 1. 39.850 | 1. 40098 41. 50
73. 1 | 1. 36678 | 1. 36919 39. 10 78. 1 | 1. 39916 | 1. 40164 41. 55
73. 2 | 1. 36742 | 1. 36983 39. 15 78. 2 | 1. 39.982 | 1. 40230 41. 60
73. 3 | 1. 36805 | 1.37047 39. 20 78. 3 | 1. 40048 | 1. 40295 41. 65
73. 4 | 1.36869 | 1. 371.11 39. 25 78.4 | 1. 401 13 | 1.40361 41. 70
73. 5 | 1. 36.933 | 1. 371.76 39. 30 78. 5 | 1. 40179 | 1.40427 41. 74
73. 6 | 1. 36997 | 1. 37240 39. 35 78. 6 | 1. 40245 | 1. 40493 41. 79
73. 7 | 1. 37061 | 1. 37304 39. 39 78. 7 | 1.40311 | 1. 40559 4.1. 84
73. 8 || 1. 37125 | 1, 37368 39. 44 78. 8 | 1.40377 | 1. 40625 4.1. 89
73. 9 || 1. 37.189 | 1. 374.32 39. 49 78. 9 | 1. 40443 | 1. 40691 41. 94
74. 0 | 1. 37254 | 1. 37496 39. 54 79. 0 | 1. 40509 i. 40758 41. 99
74. 1 | 1. 373.18 | 1. 37561 39, 59 79. 1 | 1. 40575 | 1. 40824 42. 03
74. 2 | 1. 37382 | 1. 37625 39. 64 79. 2 | 1. 40641 | 1. 40890 42, 08
74. 3 | 1. 37446 | 1. 37689 39. 69 79. 3 | 1. 40707 | 1. 40956 42. 13
74. 4 | 1. 37510 | 1. 37754 39. 74 79. 4 | 1. 40774 | 1. 41023 42. 18
74. 5 | 1. 37575 | 1. 37818 39. 79 79. 5 | 1. 40840 | 1. 41089 42. 23
74. 6 | 1. 37639 || 1. 37883 39. 84 79. 6 | 1. 40906 | 1. 41155 42. 28
74. 7 | 1. 377.04 || 1. 37947 39. 89 79. 7 | 1. 40972 | 1. 41222 42. 32
74, 8 || 1. 37768 | 1. 38012 39, 94 79. 8 || 1. 41039 || 1. 41288 42. 37
74. 9 || 1. 37833 | 1. 38076 39, 99 79. 9 || 1.41105 | 1. 41355 42. 42
323414°–42—41
622
Circular of the National Bureau of Standards
TABLE 109.- Degrees Bria, specific gravity, and degrees Baumé of sugar solutions—
Continued
Degrees Degrees
Brix or Brix or
per- || Specific | Specific Degrees per- Specific | Specific | Degrees
cent- gravity gravity Baumé Cent- gravity gravity | Baumé
age of at at (modu– age of at, at, (modu-
sucrose | 20°/4° C 20°/20° C. lus 145) || Sucrose | 20°/4° C 20°/20° C. lus 145)
by by
weight weight
80. 0 | 1. 41172 | 1.41421 42. 47 85. 0 | 1.44539 || 1. 44794 44. 86
80. 1 | 1. 41238 | 1. 41488 42. 52 85. 1 | 1. 44607 | 1. 44863 44. 91
80. 2 | 1. 41304 | 1. 41554 42. 57 85. 2 | 1.44675 | 1.44931 44. 95
80. 3 | 1.4.1371 | 1. 41621 42. 61 85. 3 | 1.44744 | 1. 45000 45. 00
80. 4 | 1.41437 | 1. 41688 4.2. 66 85. 4 | 1.44812 | 1. 4506.8 45. 05
80. 5 | 1. 41504 | 1. 41754 42, 71 85. 5 | 1. 44881 | 1.45137 45. 09
80. 6 | 1. 41571 | 1.4.1821 42. 76 85. 6 | 1.44949 | 1. 45205 45. 14
80. 7 | 1. 41637 | 1.4.1888 42. 81 85. 7 | 1. 45018 | 1. 45274 45. 19
80. 8 | 1. 41704 | 1. 41955 42. 85 85. 8 || 1. 45086 | 1.45343 45. 24
80. 9 | 1. 41771 | 1. 42022 42. 90 85. 9 | 1. 45154 | 1.454.11 45. 28
81. 0 | 1. 41837 | 1. 42088 42. 95 86. 0 | 1.45223 | 1.45480 45. 33
81. 1 || 4, 41904 | 1. 42155 43. 00 86. 1 | 1.45292 | 1. 45549 45. 38
81. 2 | 1. 41971 | 1. 42222 43. 05 86. 2 | 1. 45360 | 1. 45618 45. 42
81. 3 | 1. 42038 | 1. 42289 43. 10 86. 3 | 1. 45429 | 1. 45686 45. 47
81. 4 | 1. 42105 | 1.42356 43. 14 86. 4 | 1. 45498 || 1.45755 45. 52
81. 5 | 1. 42172 | 1. 42423 43. 19 86. 5 | 1.45567 | 1.45824 45. 57
81. 6 | 1. 42239 | 1. 42490 43. 24 86. 6 | 1. 45636 | 1. 45893 45. 61
81. 7 | 1. 42306 | 1. 42558 43. 29 86. 7 | 1.45704 | 1.45962 45. 66
81. 8 | 1.42373 | 1.42625 43. 33 86. 8 | 1.45773 | 1.46031 45. 71
81. 9 | 1. 42440 | 1. 42692 43. 38 86. 9 | 1. 45842 | 1.46100 45. 75
82. 0 | 1. 42507 | 1. 42759 43. 43 87. 0 | 1. 45911 | 1. 46170 45. 80
82. 1 | 1. 42574 | 1. 42827 43. 48 87. 1 | 1.45980 | 1. 46239 45. 85
82. 2 | 1. 42642 | 1. 42894 43. 53 87. 2 | 1. 46050 | 1. 46308 45. 89
82. 3 | 1. 42709 | 1. 42961 43. 57 87. 3 | 1. 46119 | 1. 46377 45.94
82. 4 | 1. 42776 | 1. 43029 43. 62 87. 4 | 1.46188 | 1.46446 45. 99
82. 5 | 1. 42844 | 1. 43096 43. 67 87. 5 | 1. 46257 | 1. 46516 46. 03
82, 6 | 1. 42911 | 1.43164 43. 72 87. 6 | 1. 46326 | 1. 46585 46. 08
82. 7 | 1. 42978 || 1. 43231 43. 77 87. 7 | 1. 46395 | 1. 46654 46. 13
82. 8 || 1. 43046 | 1. 43298 43. 81 87. 8 | 1.46464 | 1.46724 46. 17
82. 9 || 1. 43113 | 1. 43366 43. 86 87. 9 | 1.46534 | 1. 46793 46. 22
83. 0 | 1. 43181 | 1. 43434 43. 91 88. 0 | 1. 46603 | 1. 46862 46. 27
83. 1 | 1. 43248 | 1. 43502 43. 96 88. 1 | 1. 46673 | 1. 46932 46. 31
83. 2 | 1. 43316 | 1.43569 44. 00 88. 2 | 1.46742 | 1. 47002 46. 36
83. 3 | 1. 43384 | 1. 43637 44. 05 88. 3 | 1. 46812 | 1. 47071 46. 41
83. 4 | 1. 43451 | 1. 43705 44. 10 88. 4 | 1.46881 | 1. 47141 46.45
83. 5 | 1. 43519 | 1. 43773 44. 15 88. 5 | 1. 46950 | 1. 47210 46. 50
83. 6 | 1. 43587 | 1. 4384.1 44. 19 88. 6 | 1. 47020 | 1. 47280 46. 55
83. 7 | 1. 43654 | 1. 43908 44. 24 88. 7 | 1. 47090 | 1. 47350 46. 59
83. 8 || 1. 43722 | 1. 43976 44, 29 88. 8 || 1. 47159 | 1. 47420 46. 64
83. 9 | 1. 43790 | 1.44044 44. 34 88. 9 | 1.47229 | 1. 47489 46. 69
84. 0 | 1. 43858 | 1. 44112 44. 38 89. 0 | 1. 47299 || 1. 47559 46. 73
84. 1 | 1. 43926 | 1. 44180 44. 43 89. 1 | 1. 47368 || 1. 47629 46. 78
84. 2 | 1. 43994 | 1.44249 44. 48 89. 2 | 1. 47438 | 1. 47699 46. 83
84. 3 | 1. 44062 | 1. 44.317 44. 53 89. 3 | 1. 47508 || 1. 47769 46. 87
84. 4 | 1. 44130 | 1. 44385 44. 57 89. 4 | 1. 47578 | 1. 47839 46. 92
84. 5 | 1.44198 | 1. 44453 44. 62 89. 5 | 1. 47648 | 1. 47909 46. 97
84. 6 | 1.44266 | 1. 44521 44, 67 89. 6 | 1. 47718 | 1. 47979 47. 01
84. 7 | 1. 44334 | 1. 44590 44. 72 89. 7 | 1. 47788 | 1. 48049 47. 06
84, 8 | 1.44402 | 1.44658 44. 76 89. 8 | 1. 47858 | 1. 48119 47. 11
84.9 | 1.444.70 | 1. 44726 44. 81 89. 9 | 1. 47928 1. 48189 47. 15
Polarimetry, Saccharimetry, and the Sugars
623
TABLE 109.- Degrees Bria, specific gravity, and degrees Baumé of sugar solutions—
Continued
Degrees Degrees
Brix or Brix Or
per- Specific | Specific | Degrees per- Specific | Specific | Degrees
Cent- gravity gravity Baumé Cent- gravity gravity | Baumé
age of at at (modu- age of at, at, (modu-
sucrose | 20°/4° C 20°/20° C. lus 145) || sucrose | 20°/4° C | 20°/20° C. lus 145)
by by
weight weight
90. 0 | 1. 47998 || 1. 48259 47. 20 95. 0 | 1. 51546 | 1. 51814 49. 49
90. 1 | 1. 48068 1. 48330 47. 24 95. 1 | 1. 5.1617 | 1. 51886 49. 53
90. 2 | 1. 48138 | 1. 48400 47. 29 95. 2 | 1. 51689 | 1. 51958 49, 58
90. 3 | 1. 48.208 || 1. 48470 47. 34 95. 3 | 1. 5.1761 | 1. 52030 49. 62
90. 4 | 1. 48278 | 1.48540 47. 38 95. 4 || 1, 51833 | 1. 52102 49. 67
90. 5 | 1. 48348 | 1. 48611 47.43 95. 5 | 1, 51905 | 1. 52174 49. 71
90. 6 | 1. 484.19 | 1. 48681 47. 48 95. 6 | 1. 51977 | 1. 5.2246 49. 76
90. 7 | 1. 48489 | 1. 48752 47. 52 95. 7 | 1. 52049 | 1. 52318 49. 80
90. 8 || 1. 48559 | 1. 48822 4.7. 57 95. 8 | 1. 52121 | 1. 52390 49. 85
90. 9 || 1. 48630 | 1. 48893 47. 61 95. 9 || 1. 52193 | 1. 52463 49. 90
91. 0 | 1. 48700 | 1. 48963 47. 66 96. 0 | 1. 52266 | 1. 52535 49. 94
91. 1 | 1. 48.771 | 1. 49034 47. 71 96. 1 | 1. 52338 | 1. 52607 49. 98
91. 2 | 1. 48841 | 1. 49104 47. 75 96. 2 | 1. 52410 | 1. 5.2680 50. 03
91. 3 | 1. 489.12 | 1. 491.75 47. 80 96. 3 | 1. 52482 | 1. 52752 50. 08
91. 4 | 1. 48982 | 1. 49246 47. 84 96. 4 | 1. 5.2555 | 1. 52824 50. 12
91. 5 | 1. 49053 | 1. 49316 47. 89 96. 5 | 1. 52627 | 1. 52897 50. 16
91. 6 | 1. 49123 | 1. 49387 47. 94 96. 6 | 1. 52699 || 1. 52969 50. 21
91. 7 | 1. 491.94 | 1. 49.458 47. 98 96. 7 | 1. 52772 | 1. 53042 50. 25
91. 8 | 1. 49265 | 1. 49529 48. 03 96. 8 | 1. 5.2844 | 1. 53114 50. 30
91. 9 | 1. 49336 | 1. 49600 48. 08 96. 9 | 1. 52917 | 1. 53187 50. 34
92. 0 | 1. 49.406 | 1. 49671 48. 12 97. 0 | 1. 52989 | 1. 53260 50. 39
92. 1 | 1. 49477 | 1. 49741 48. 17 97. 1 | 1. 53062 | 1. 53332 50. 43
92. 2 | 1. 49548 | 1. 49812 48. 21 97. 2 | 1. 53134 | 1. 53405 50. 48
92. 3 | 1. 496.19 | 1. 49883 48. 26 97. 3 | 1. 53207 | 1. 53478 50. 52
92. 4 | 1.49690 | 1. 49954 48. 30 97. 4 || 1. 53279 | 1. 53551 50. 57
92. 5 | 1. 49761 | 1. 50026 48. 35 97. 5 | 1. 53352 | 1. 53623 50. 61
92. 6 | 1.49832 | 1. 50097 48. 40 97. 6 | 1. 53425 | 1. 53696 50. 66
92. 7 | 1. 49903 | 1. 50168 48. 44 97. 7 | 1. 53498 || 1. 53769 50. 70
92. 8 | 1. 49.974 | 1. 50239 48. 49 97. 8 || 1. 53570 | 1. 53.842 50. 75
92. 9 || 1. 5004.5 | 1. 50310 48. 53 97. 9 || 1. 53643 | 1. 53915 50. 79
93. 0 | 1. 501 16 | 1. 50381 48. 58 98. 0 | 1. 53716 | 1. 53988 50. 84
93. 1 | 1. 50187 | 1. 50453 48. 62 98. 1 | 1. 53789 | 1. 54061 50. 88
93. 2 | 1. 50258 | 1. 50524 48. 67 98. 2 | 1. 53862 | 1. 54.134 50. 93
93. 3 | 1. 50329 | 1. 50595 48. 72 98. 3 | 1. 53935 | 1. 54207 50. 97
93. 4 | 1. 50401 | 1. 50667 48. 76 98. 4 | 1. 54008 || 1. 54280 51. 02
93. 5 | 1. 50472 | 1. 50738 48. 81 98. 5 | 1. 54081 | 1. 54.353 51. 06
93. 6 | 1. 50543 | 1. 50810 48. 85 98. 6 | 1. 54154 | 1. 54426 51. 10
93. 7 | 1. 50615 | 1. 50881 48. 90 98. 7 | 1. 54227 | 1. 5.4499 51. 15
93. 8 || 1. 50686 | 1. 50952 48. 94 98. 8 | 1. 54300 | 1. 54573 51. 19
93. 9 || 1. 50757 | 1. 51024 48. 99 98. 9 1, 54373 | 1. 54646 51. 24
94. 0 | 1. 50829 | 1. 51096 49. 03 99. 0 | 1. 54446 | 1. 54719 51. 28
94. 1 | 1. 50900 | 1. 5.1167 49. 08 99. 1 | 1. 545.19 | 1. 54793 51. 33
94. 2 | 1. 50972 | 1. 5.1239 49. 12 99. 2 | 1, 54593 | 1. 54866 51. 37
94. 3 | 1. 51044 | 1. 5.1311 49. 17 99. 3 | 1. 54666 | 1. 54939 51. 42
94. 4 | 1. 51115 | 1. 51.382 49. 22 99. 4 | 1. 54739 | 1. 55013 51. 46
94. 5 | 1. 51187 | 1. 51454 49. 26 99. 5 | 1. 54813 | 1. 55087 51. 50
94. 6 | 1. 5.1258 | 1. 51526 49. 31 99. 6 | 1. 54886 | 1. 55160 51. 55
94. 7 | 1. 51330 | 1. 5.1598 49. 35 99. 7 | 1. 54960 | 1. 55234 51. 59
94. 8 | 1. 5.1402 | 1. 51670 49. 40 99. 8 | 1. 55033 | 1. 55307 51. 64
94. 9 | 1. 51474 | 1. 51742 49. 44 99. 9 | 1. 55106 | 1. 55381 51. 68
100. 0 | 1. 5.5180 | 1. 55.454 51. 73
624 Circular of the National Bureau of Standards
TABLE 110.- Temperature corrections to readings of Bria: hydrometers (standard at
20° C)
[This table is calculated using the data on thermal expansion of sugar solutions
by Plato,' assuming the instrument to be of Jena 16111 glass. The table should
be used with caution and only for approximate results when the temperature
differs much from the standard temperature or from the temperature of the
surrounding airl
This table also may be used with instruments that are standard at 17.5° C,
as follows: Find the correction for reducing to 20°C in the usual way, and to this
add the correction at 17.5°C with the sign changed; i. e., regarded as positive.
For example, if the instrument reads 20.00 percent at 24° C, the correction to
17.5°C is +0.26+0.15=0.41, and the true percentage of sugar is 20.41. If it reads
20.00 percent at 18°C, the correction to 17.5° C is —0.12+0.15 = +0.03, and the
true percentage of sugar is 20.03. If it reads 20.00 at 15° C, the correction is
—0.28–H 0.15 = –0.13, and the true percentage of sugar is 19.87.
Observed percentage of Sugar

Temperature| 0 5 || 10 | 15 20 || 25 || 30 || 35 | 40 || 45 || 50 || 55 60 || 70
Subtract from observed percentage
oC
0 0.30 0.49 || 0. 65 0.77 || 0.89 || 0.99 || 1,08 1, 16 | 1. 24 | 1.31 | 1.37 | 1.41 | 1.44 | 1.49
5 . 36 | . 47 | . 56 65 | . 73 . 80 | . 86 91 . 97 | 1.01 | 1.05 | 1.08 | 1. 10 | 1. 14
10 32 ; 43 48 52 57 | . 60 64 67 § . 72 74 75 77
11 31 5 40 44 48 51 . 55 58 60 . 65 66 68 70
12 29 32 36 40 43 46 | . 50 52 54 56 58 59 60 62
13 26 29 32 35 38 41 . 44 46 48 49 51 52 53 55
14 24 26 29 31 34 36 .38 40 41 42 44 45 46 47
15 20 22 24 26 28 30 | . 32 33 34 36 36 37 38 39
16 17 18 20 22 23 25 | . 26 27 28 28 29 3() 31 32
17 13 14 15 16 18 19 . 20 20 21 21 22 23 23 24
17. 5 11 12 12 14 15 16 . 16 17 17 18 18 19 19 20
18 09 J0 10 II 12 13 | . 13 14 14 14 15 15 J 5 16
19 05 05 05 06 06 06 | . 07 07 07 07 08 08 08 08
21 0.04 || 0.05 || 0.06 || 0.06 || 0.06 0.07 || 0.07 || 0.07 || 0.07 || 0.08 || 0.08 || 0.08 || 0.08 || 0.09
22 10 10 11 12 12 13 | . 14 14 15 15 16 16 16 16
23 16 16 17 17 19 20 | . 21 21 22 23 24 24 24 24
24 21 22 23 24 26 27 | . 28 29 30 31 32 32 32 32
25 27 28 30 31 32 34 | . 35 36 38 38 39 39 40 39
26 33 34 36 37 40 40 | . 42 44 46 47 47 48 48 48
27 40 4| 42 44 46 48 . 50 52 54 54 55 56 56 56
28 46 47 49 51 54 56 , 58 60 61 62 63 64 64 64
29 54 55 56 59 6] 63 | . 66 68 70 70 71 72 72 72
30 61 62 63 66 68 71 | . 73 76 78 78 79 80 80 81
35 . 99 || 1.01 | 1.02 | 1.06 | 1. 10 | 1. 13 | 1. 16 | 1.18 | 1. 20 | 1. 21 | 1.22 | 1.22 | 1.23 | 1.22
40 1.42 | 1.45 | 1.47 | 1.51 | 1.54 | 1.57 | 1.60 | 1.62 | 1.64 1.65 | 1.65 | 1.65 | 1.66 | 1.65
45 1.91 | 1.94 | 1.96 || 2.00 2.03 ſ 2.05 || 2.07 || 2.09 || 2. 10 || 2. 10 || 2. 10 || 2. 10 || 2. 10 || 2.08
50 2.46 2.48 2.50 2.53 2, 56 2.57 2.58 2.59 || 2.59 2.58 2.58 2.57 2.56 2.52
55 3.05 || 3.07 || 3.09 || 3. 12 3. 12 3. 12 3. 12 3. 11 || 3. 10 || 3.08 || 3.07 || 3.05 || 3.03 || 2.97
60 3. 69 || 3.72 3.73 3.73 || 3.72 3.70 || 3.67 || 3.65 || 3. 62 3. 60 | 3. 57 || 3. 54 || 3. 50 || 3.43
65 4. 4 || 4.4 || 4.4 || 4.4 || 4.4 4.4 || 4, 3 || 4. 2 || 4. 2 || 4, 1 || 4. 1 || 4.0 4.0 3.9
70 5. 1 || 5. 1 || 5. 1 || 5, 0 || 5.0 | 5.0 4.9 || 4.8 || 4.8 || 4, 7 || 4.7 4.6 |. 4.6 4. 4
75 6. 1 || 6. 0 || 6. 0 || 5.9 || 5.8 || 5.8 || 5. 7 || 5.6 || 5. 5 || 5.4 || 5.4 || 5. 3 || 5, 2 5 0
80 7. 1 || 7, 0 || 7. 0 || 6.9 || 6.8 || 6.7 || 6, 6 || 6.4 || 6. 3 || 6. 2 | 6, 1 || 6. 0 || 5.9 5. 6
Wiss. Abh. Kaiserlichen Normal-Eichungs-Kommission 2, 140 (1900).
Polarimetry, Saccharimetry, and the Sugars
625
TABLE 111.—Temperature corrections to readings of Baumé hydrometers, National
Bureau of Standards Baumé scale for sugar solutions (standard at 20° C)
[This table is based on the values of the thermal expansion of Sugar Solutions by Plato, assuming the instru-
ment to be of Jena 16111 glass. The table should be used with caution and only for approximate results
when the temperature differs much from the standard or from the temperature of the surrounding air]
Observed degrees Baumé
Tempera- 0 5 10 15 20 25 30 35 40
ture
Subtract from observed degrees Baumé
oC
0 0. 17 0.34 (). 47 0. 57 0.65 0.72 0.77 0.79 0.81
5 . 21 . 30 . 39 . 45 . 51 . 55 . 59 . 60 . 61
10 . 18 . 23 . 28 . 32 . 36 . 38 . 40 . 41 .42
11 . 18 . 22 . 26 . 29 . 32 . 34 . 36 . 37 . 38
12 . 17 . 20 . 23 . 26 . 29 . 31 . 32 . 33 . 34
13 . 15 . 18 . 20 . 23 . 25 . 27 . 28 . 29 . 29
14 . 14 . 16 . 18 . 20 . 22 . 23 . 24 . 25 . 25
15 . 11 . 13 . 15 . 17 . 18 . 20 . 20 . 21 . 21
16 . 10 . 11 . 13 . 14 . 15 . 15 . 16 . 17 . 17
17 . 07 . 08 . 10 . 11 . 11 . 11 . 13 . 13 . 13
18 . 05 . 06 . 07 . 07 . 08 . 08 . 08 . 08 . 09
19 . 03 . 03 . 03 . 03 . 04 . 04 . 04 . 04 . 05
Add to observed degrees Baumé
21 0.02 0.03 0.03 0.04 0.04 0.04 0.04 0.05 0.05
22 . 06 . 06 . 07 . 07 .08 . ()8 . 08 09 . 09
23 . ().9 . 09 ... 10 . 11 . 12 . 13 . 13 . 13 . 13
24 . 12 . 13 . 14 - 15 16 . 17 . 17 . 17 . 17
25 15 . 17 . 18 . 19 . 20 . 21 . 21 . 21 . 21
26 . 19 . 20 . 22 . 22 . 24 . 26 . 26 . 26 . 26
27 . 23 . 23 . 25 . 27 . 29 . 30 . 30 . 30 . 30
28 . 26 . 27 . 29 . 31 . 33 . 34 . 35 . 35 . 34
29 . 31 . 31 . 34 . 35 . 37 . 38 . 39 . 39 . 38
30 . 35 . 35 . 38 . 39 . 42 . 43 . 44 . 43 . 43
35 . 56 . 57 . 60 . 63 . 65 . 66 . 66 . 66 . 65
40 . 81 . 82 .85 . 87 . 89 . 90 90 . 89 . 88
45 1. 09 1.09 1, 12 1. 14 1. 15 1. 15 1. 14 1. 13 1. 11
50 1. 40 1. 39 1.42 1.42 1. 43 1. 41 1. 40 1. 37 1. 33
55 1. 74 1. 72 1. 73 1. 73 1. 71 1. 69 1. 66 1. 62 1. 57
60 2. 10 2.08 2. 06 2. 05 2.00 1.97 1. 92 1. 87 1.82
65 2. 5 2.5 2.4 2.4 2. 3 2. 2 2. 2 2. 1 2. 1
70 2.9 2.8 2.8 2.8 2. 6 2, 6 2. 5 2.4 2. 3
75 3. 5 3.3 3. 2 3.2 3. 1 3.0 2.9 2. 7 2. 6
80 4. 0 3.9 3. 8 3. 7 3.5 3.4 3. 3 3. 1 2.8
|
TABLE 112.-Comparison of Baumé scales
Corresponding degrees Baume Corresponding degrees Baume
Percentage Percentage
Of SucroSe Or “New” “Old” NBS Scale || of sucrose or “New” “Old” NBS scale
degrees Brix Scale Scale (modulus || degrees Brix Scale Scale (modulus
(modulus (modulus 145) (modulus (modulus 145)
146.78) 144) 146.78) 144)
0 0.0 0.0 0.00 50 27.7 27.2 27. 28
5 2.8 2.8 2. 79 55 30.4 29.8 29.90
10 5. 7 5, 6 5. 57 60 33. 0 32.4 32.49
15 8. 5 8. 3 8. 34 65 35. 6 34.9 35. 04
20 11.3 11. 1 11. 10 70 38. 1 37.4 37. 56
25 14. 1 13. 8 13.84 75 40. 6 39.9 40.03
30 16.8 16. 5 16. 57 80 43. 1 42.3 42.47
35 19. 6 19. 2 19.28 85 45.5 44.7 44.86
40 22, 3 21.9 21.97 90 47. 9 47.0 47. 20
45 25. 0 24.6 24.63 95 50.3 49.3 49.49
100 ------------|------------ 51. 73

626. Circular of the National Bureau of Standards
TABLE 113.−Density of solutions of came sugar at 20° C.
[This table is the basis for standardizing hydrometers indicating percent of Sugar
! According to F. Plato (Kaiserlichen Normal-Eichungs-Kommission, Wiss.
at 20° C.]
Percent- Tenths of percent
age of
S te
ugar 0 1 2 3 4
-
() (). 998.234 0. 998622 0. 999010 (). 999398 (). 999.786
1 1. 002120 1. 0.02509 1. 002897 1. 003286 1. 003675
2 1. 006015 1. 0.06405 1. 0.06796 1. 007188 1. 007580
3 1. 009934 1. 010327 1. 0.10721 1. 011 115 1. 011510
4 1. 013881 1. O14277 1. 014673 1. 0.15070 1. 015467
5 1. 0.17854 1. 018253 1. 018652 1. 0.19052 1. 01945.1
6 1. 021855 1. 022257 1. 022659 1. 023061 1. 023463
7 1. 025.885 1. 026.289 1. 026694 1. 027099 1. 0.27504
8 1. 029942 1. 030349 1. 030757 1. 031165 1. 031573
9 1. 034029 1. 034439 1. 034850 1. 035260 1. 035671
10 1. 038143 1, 038556 1. 0389.70 1. 039383 1. O39797
11 1. 042288 1. 042704 1. 043121 1. 043537 1. 043954
12 1. 046462 1. 046881 1. 047.300 1. 047720 1. 048140
13 1. 050665 1. 051087 1. 051510 1. 051933 1. 052356
14 1. 054900 1. 055.325 1. 0557.51 1. 0561.76 1. 056602
15 1. 0.5916.5 1. 059593 1. 060022 1, 060451 1, 060880
16 1. 063460 1. 063892 1. 064324 1. 064756 1. 065.188
17 1. 067789 1. 068223 1. 068658 1. 069093 1. 069529
18 1. 0721.47 1. 072585 1. 073023 1. 073461 1. 073900
19 1. 0.76537 1. O76978 1. 0.77419 1. 0.77860 1. 078302
20 1. 080959 1. 081403 1. 08.1848 1. 082292 1. 082737
21 1. 085414 1. 085861 1. 086309 1. 086757 1. 087205
22 1. 089900 1. 090351 1. 090802 1. 09.1253 1. 09 1704
23 1. 09.4420 1. 094874 1. 095328 1. 095782 1. 096236
24 1. 0.98971 1. 099428 1. 099886 1. 100344 1. 100802
25 1. 103557 1. 104017 1. 104.478 1. 104938 1. 105400
26 1. 1081.75 1. 108639 1. 109.103 1. 109568 1. 1100.33
27 1. 112828 1. 113295 1. 113763 1. 114229 1. 114697
28 1. 117512 1. 117982 1. 118453 1. 118923 1. 119395
29 1. 122231 1. 122705 1. 1231.79 1. 123653 1. 124128
30 1. 126984 1. 127461 1. 127939 1. 1284.17 1. 128896
31 1. 131773 1. 132254 1. 132735 1. 133216 1. 133698
32 1. 136596 1. 137080 1. 137565 1. 138049 1. 138534
33 1. 141453 1. 141941 1. 142429 1. 142916 1. 143405
34 1. 146345 1. 146836 1. 147328 1. 147820 1. 148313
35 1. 151275 1. 151770 1. 152265 1. 152760 1. 153256
36 1. 156238 1. 156736 1. 157235 1. 157733 1. 158233
37 1. 161236 1. 161738 1. 162240 1. 162742 1. 163245
38 1. 166269 1. 166775 1. 167281 1. 167786 1. 168293
39 1. 171340 1. 171849 1. 1723.59 1. 172869 1. 1733.79
40 1. 176447 1. 176960 1. 177473 1. 177987 1. 178501
41 1. 181592 1. 182108 1. 182625 1. 183142 1. 183660
42 1. 186773 1. 187293 1. 187814 1. 188335 1. 188856
43 1. 191993 1. 192517 1. 193041 1, 193565 1. 194090
44 1. 197247 1. 1977.75 1. 198303 1, 198832 1. 199360
Abh. 2, 153 (1900).
Polarimetry,
627
Saccharimetry, and the Sugars
TABLE 113.-Density of solutions of cane sugar at 20° C.—Continued
Percent-
age of
Sugar
Tenths of percent
5 6 7 8 9
1. 000174 1. 000563 1. 000.952 1. 001342 1. 001.73 |
1. 004.064 1. 004.453 1. 004844 1. 00:5234 1. 005624.
1. 007972 1. 008363 1. 008755 1. 009.148 1. 0.0954. 1
1. 011904 1. 012298 1. 012694 1. 0.13089 1. 013485
1. 015864 1. 016261 1. 016659 1. 017058 1. 017456
1. 01985] 1. 020251 1. 020651 1. 021053 1. 0214.54
1. 023867 1. 024270 1. 024673 1. 025.077 1. 025481
1. 027910 1. 028316 1. 0287.22 1. 029128 1. 029.535
1. 031982 1. 032391 1. 032800 1. 033209 1. 033619
1. 036082 1. 036494 1. 036906 1. 0373.18 1. 037730
1. 04:02:12 1, 0.40626 1. 041041 1. 041456 1, 041872
1. 04:4370 1. 044788 1. 045206 1. 045625 1. 046043
1. 048.559 1. 048980 1. 04940.1 1. 049822 1. 050243
1. 052778 1. 053202 1. 053626 1. 054050 1. 054475
1. 057029 1. 05745.5 1. 057882 1. 058310 1. 058.737
1. 06.1308 1. 06.1738 1. 0621.68 1. 062598 1. 0630.29
1. 065621 1. 066054 1. 066487 1. 066921 1. 067355
1. 069964 1. 070400 1. 070836 1. 071273 1. 071710
1. 074338 1. 074777 1. 075217 1. 075657 1. 076097
1. 0.78744 1. 07918.7 1. 0.79629 1. 080072 1. 080515
1. 083182 1. 083628 1. 084074 1. 084520 1. 084967
1. 0.87652 1. 088101 1. 0885.50 1. 089000 1. 089450
1. 09:2155 1. 09.2607 1. 093060 1. 093513 1. 093966
1. 096691 1. 097147 1. 097603 1. 098058 1. 098514
1. 10.1259 1. 101718 1. 102177 1. 102637 1, 103097
1. 105862 1. 106324 1. 106786 1. 107248 1. 107711
1. 110497 1. 110963 1. 111429 1. 111895 1. 112361
1. 115166 1. 115635 1. 116104 1. 116572 1. 117042
1. 119867 1. 120339 1. 120812 1. 121284 1. 121757
1. 124603 1. 125079 1. 125555 1. 126030 1. 126507
1. 129374 1. 129853 1. 130332 1. 130812 1. 131292
1. 134180 1. 134663 1. 1351.46 1. 135628 1. 136112
1. 139020 1. 139506 1. 139993 1. 140479 1. 140966
1. 143894 1. 144384 1. 144874 1. 145363 1. 145854
1. 148805 1. 149298 1. 149792 1. 150286 1. 150780
1. 153752 1. 154249 1. 154746 1. 155242 1. 155740
1. 158733 1. 159233 1. 159733 1. 160233 1. 160734
1. 163748 1. 164252 1. 164756 1. 165259 1. 165764
1. 168800 1. 169307 1. 169815 1. 170322 1. 170831
1. 173889 1. 174400 1. 174911 1. 175423 1. 175935
1. 179014 1. 179527 1. 180044 1. 180560 1, 181076
1. 1841.78 1. 1846.96 1. 185215 1. 185734 1, 186253
1. 1893.79 1. 189901 1. 190423 1. 190946 1. 191469
1. 194616 1. 1951.41 1. 195667 1. 196193 1. 1967.20
1. 199890 1. 200420 1. 200950 1. 201480 1. 202010
628
Circular of the National Bureau of Standards
TABLE 113.−Density of solutions of came sugar at 20° C.—Continued
Tenths of percent
Percent-
age of
Sugar 0 1 2 3 4
45 1. 202540 1. 203071 1. 203603 1. 204 136 1. 204668
46 1. 207870 1. 208405 1. 208940 1. 209477 1. 2100.13
47 1. 213238 1. 213777 1. 214317 1. 214856 1. 215395
48 1. 218643 1. 21918.5 1. 219729 1. 220272 1. 220815
49 1. 224086 1. 224632 1. 22.5180 1. 2257.27 1. 226274
50 1. 229567 1. 2301.17 1. 230668 1. 231219 1. 231770
51 1. 235085 1. 235639 1. 236.194 1. 236748 1. 237303
52 1. 240641 1. 24.1198 1. 24.1757 1. 242315 1. 242873
53 1. 246234 1. 246.795 1. 247358 1, 247920 1. 2484.82
54 1. 25 1866 1. 252431 1. 25.2997 1. 253.563 1. 254.129
55 1. 257535 1. 258104 1. 258674 1. 259244 1. 259815
56 1. 263243 1. 263816 1. 264390 1. 264963 1. 265537
57 1. 268989 1. 269565 1. 270143 1. 270720 1. 271299
58 1. 274774 1. 27.5354 1. 275936 1, 2765.17 1. 277098
59 1. 280595 1. 281179 1. 28.1764 1. 282349 1. 282935
60 1. 286456 1. 287044 1. 287633 1. 288222 1. 288811
61 1. 292354 1. 29.2946 1. 293539 1. 294131 1. 294725
62 1. 298.291 1. 298886 1. 299483 1. 300079 1. 300677
63 1. 304.267 1. 304867 1. 305467 1. 306068 1. 306669
64 1. 310282 1. 310885 1. 31 1489 1. 312093 1. 312699
65 1. 316334 1. 316941 1. 317549 1. 318157 1. 318766
66 1. 32.2425 1. 323036 1. 323648 1. 324259 1. 324872
67 1. 328554 1. 3291.70 1. 329785 1. 330401 1. 331017
68 1. 334722 1. 335342 1. 335961 1. 336581 1. 337200
69 1. 340928 1. 34.1551 1. 342174 1. 342798 1. 343421
70 1. 347174 1. 347801 1. 348427 1. 349055 1. 349682
71 1. 353456 1. 3540.87 1. 354,717 1. 355349 1. 355.980
72 1. 359778 1. 360413 1. 361047 1. 36.1682 1. 362317
73 1. 366,139 1. 366777 1. 3674.15 1. 368054 1. 36.8693
74 1. 372536 1. 373.178 1. 373820 1. 374463 1. 37.5105
75 1. 378971 1. 3796.17 1. 380262 1. 380909 1. 38.1555
76 1. 3854.46 1. 386096 1. 386745 1. 38.7396 1. 388045
77 1. 39.1956 1. 39.2610 1. 393263 1. 3939.17 1. 394.571
78 1. 398505 1. 399.162 1. 39.9819 1. 400477 1. 401134
79 1. 405091 1. 405752 1. 406412 1. 407074 1. 407735
80 1. 411715 1. 412380 1. 413044 1. 413709 1. 41.4374
81 1. 418374 1. 419043 1. 419711 1. 420380 1. 421049
82 1. 425072 1. 425744 1. 426416 1. 427089 1. 427761
83 1. 431807 1. 432483 1. 433158. 1. 433835 1. 434511
84 1. 4385.79 1. 439259 1. 439938 1. 440619 1. 441299
85 1. 445388 1. 446071 1. 446754 1. 447438 1. 448121
86 1. 452232 1. 452919 1. 453605 1. 454292 1. 454980
87 1. 459114 1. 459.805 1. 460495 1. 461186 1. 461877
88 1. 466032 1. 466726 1. 467420 1. 4681 15 1. 468810
89 1. 4.72986 1. 473684 1. 474381 1. 475080 1. 475779
Polarimetry, Saccharimetry, and the Sugars
629.
TABLE 113.—Density of solutions of came sugar at 20° C.—Continued
Tenths of percent
Percent-
age of
Sugar 5 6 7 8 9
45 1. 205200 1. 205733 1. 206266 1. 206801 1. 207335
46 1, 210549 1, 211086 1. 21 1623 1. 212162 1. 212700
47 1. 215936 1. 216476 1. 21701.7 1. 217559 1. 218 101
48 1. 22.1360 1. 22 1904 1. 222449 1, 222995 1. 223540
49 1. 2268.23 1. 2273.71 1, 227.919 1. 228469 1. 2290 18
50 1. 23.2322 1. 232874 1. 233426 1. 233979 1. 234532
51 1. 237859 1. 238414 1. 238970 1. 239527 1. 240084
52 1. 243433 1. 243992 1. 244552 1. 2451 13 1. 245673
53 1. 249046 1. 249609 1. 2501.72 1. 250737 1. 25.1301
54 1. 254697 1. 255.264 1. 255831 1. 25.6400 1. 256967
55 1. 260385 1. 260955 1. 261527 1. 262099 1. 26.267.1
56 1. 2661 12 1. 266686 1. 267.261 1. 267837 1. 2684.13
57 1. 27 1877 1. 272455 1. 27.3035 1. 273614 1. 274194
58 1. 277680 1. 278262 1. 278844 1. 27.9428 1. 280011
59 1. 283.521 1. 284 107 1. 284694 1. 285281 1. 285869
60 1. 2894.01 1. 28.999.1 1. 290581 1. 291 172 1. 29.1763
61 1. 295318 1. 29.5911 1. 296.506 1. 297 100 1. 29.7696
62 1. 301274 1. 301871 1. 302470 1. 303068 1. 303.668
63 1. 30.7271 1. 30.7872 1. 308475 1. 30.9077 1. 309.680
64 1. 313304 1. 31.3909 1. 314515 1. 315121 1. 3 15728
65 1. 319374 1. 319983 1. 320593 1. 321203 1. 32.1814
66 1. 325484 1. 326097 1. 3267.11 1. 327325 1. 327.940
67 1. 33.1633 1. 332250 1. 332868 1. 333485 1. 334 103
68 1. 337821 1. 338441 1. 339063 1. 339684 1. 340306
69 1. 34.4046 1. 344671 1. 345296 1. 345922 1. 346547
70 1. 350311 1. 350939 1. 351568 1. 352197 1. 352827
71 1. 356612 1. 357245 1. 357877 1. 35851 1 1. 35.9144
72 1. 36295.3 1. 363590 1. 364.226 1. 364864 1. 365501
73 1. 369333 1. 36997.3 1. 370613 1. 371254 1. 371894
74 1. 375749 1. 376392 1. 377036 1. 377680 1. 3783.26
75 1. 382203 1. 38285.1 1. 383499 1. 384.148 1. 384796
76 1. 388696 1. 389347 1. 389999 1. 39.0651 1. 39.1303
77 1. 395.226 1. 39.5881 1. 396536 1. 397.192 1. 397848
78 1. 401793 1. 403452 1. 403111 1. 403771 1. 404430
79 1. 408398 1. 409061 1. 409723 1. 410387 1. 411051
80 1. 415040 1. 415706 1. 416373 1. 417039 1. 417707
81 1. 421719 1. 422390 1. 423059 1. 423730 1. 424400
82 1. 428435 1. 429.109 1. 429782 1. 430457 1. 431131
83 1. 435.188 1. 435866 1. 436543 1. 437.222 1. 437900
84 1. 44.1980 1. 442661 1. 443342 1. 444024 1. 444705
85 1. 448806 1. 449491 1. 4501.75 1. 450860 1. 451545
86 1. 455668 1. 456.357 1. 457045 1. 457735 1. 458424
87 1. 462568 1. 4.63260 1. 463953 1. 464645 1. 465.338
88 1. 469504 1. 470200 1. 470896 1. 471592 1. 472.289
89 1. 47647.7 1. 477.176 1. 477876 1, 47.8575 1, 479275
630
Circular of the National Bureau of Standards
TABLE 113.-Density of solutions of cane sugar at 20° C.–Continued

Tenths of percent
Percent-
age of
Sugar 0 1 2 3 4
90 1. 479976 1. 480677 1. 481378 1. 482080 1. 482782
91 1. 487002 1. 487.707 1. 4884.11 1. 489.117 1. 4898.23
92 1. 4.94063 1. 494771 1. 495479 1. 496.188 1. 496897
93 1. 501158 1. 501870 1. 502582 1. 503293 1. 504006
94 1. 508289 1. 509004 1. 509720 1. 510435 1. 511151
95 1. 515455 1. 5.16174 1. 516893 1. 5.17612 1. 518332
96 1. 5.22656 1. 523378 1. 524.100 1. 524823 1. 5.25546
97 1. 5298.91 1. 530616 1. 531342 1. 532068 1. 532794
98 1. 537161 1. 537889 1. 5386.18 1. 539347 1. 54.0076
99 1. 544.462 1. 545.194 1. 545926 1. 546659 1. 547392
100-- - - - - - 1. 551800 ------------------------------------|-----------
Polarimetry, Saccharimetry, and the Sugars 631
TABLE 113.−Density of solutions of came sugar at 20° C.—Continued
Tenth
Percent- enths of percent
age of
Sugar 5 6 7 8 9
90 1. 483484 1. 484 187 1. 484890 1. 485593 1. 486297
9 | 1. 490528 1. 491234 1. 49.1941 1. 492647 1. 493355
92 1. 497606 1. 4983.16 1. 49.9026 1. 499.736 1. 500447
93 1. 504719 1. 505432 1. 5061.46 1. 506859 1. 507574.
94 1. 51.1868 1. 5.12585 1. 513302 1. 5.14019 1. 514.737
95 1. 5.19051 1. 5.19771 1. 520492 1. 521212 1. 521934
96 1. 526.269 1. 526993 1. 5277.17 1. 5.28441 1. 529166
97 1. 533521 1. 534248 1. 534976 1. 535704 1. 536432
98 1. 540806 1. 541536 1, 54.2267 1. 54.2998 1. 543730
99 1. 548127 1. 548861 1. 549595 1. 550329 1. 551064
632
Circular of the National Bureau of Standards
TABLE 114.—Bria, apparent density, apparent specific gravity, and grams of sucrose
per 100 ml of sugar solutions
Column 1 gives Brix or percentage of sucrose in the solution.
Column 2 gives apparent density, that is, the weight in air with brass weights
of 1 ml of solution at 20° C. The values in this column correspond to the values
of true density (table 113), having been obtained by means of the formula
M = W[1+: ‘dº — |)]= W(1+iºn)"
#(#= p 1000
which may be utilized for converting apparent density into true density, and vice
versa, by considering that M, the weight in vacuo, and W, the apparent weight,
refer to 1 ml, since true density is defined as the weight in vacuo of 1 ml, and the
apparent density as the weight of 1 ml of substance in air with brass weights.
p is the density of air, which has been taken as 0.0012046;” d, the density of the solu-
tion, dº the density of the weights, which has been taken as 8.4.
Column 3 gives the apparent specific gravity at 20° C. The values in this col-
umn were obtained by dividing the apparent density in column 2 by the apparent
density of water at 20° C., which was taken as 0.997174.3
Column 4 gives the grams sucrose (weighed in vacuo) per 100 ml of solution.
The values in the table were calculated in three sections by different individuals;
thus from 40 to 60 Brix by Peters and Phelps (BS Tech. Paper T338, 1927); 60 to
83.9 Brix by Brewster and Phelps (NBS Research Paper RP536, 1933); and the
remaining values, 0 to 40 and 84 to 95 Brix by Snyder, Saunders, and Golden of
this Bureau. After the computations were completed, the tabulations were made
by rounding off the values to the last figure given. The values are considered
exact to + 1 in the fifth decimal.

3r - T8...II] … I U.tº L. L * TàII].S O
ºil spººn º' | * |º soºn | ºff º'
crose } deº, at gº at per }m crose } deº. at gº; at per º, m
Å. 4 20° C/20° C. i. º Yº 20° C/20° C in º
I 2 3 4 1 2 3 4
O. 0 || O. 99717 | 1. 00000 (). 000 2. 0 | 1. O0.495 | 1. O0780 2. 012
... 1 . 997.56 . 00039 ... 100 ... 1 . 0.0534 . 00819 . 113
, 2 . 99.795 00078 . 200 ... 2 . 00574 . 00859 . 215
. 3 , 99834 . 00117 . 300 . 3 . 0.0613 . 00898 . 317
. 4 . 998.72 . 00156 . 400 ... 4 . 00652 . 0.0937 . 418
. 5 . 999.11 . 001.94 , 500 . 5 . 00691 . 00977 . 520
... 6 . 99950 . 00233 . 600 ... 6 . 007:30 , 0.1016 . 622
... 7 . 99989 . 00272 . 701 ... 7 . 00769 . 0.1055 . 724
. 8 | 1. 00028 . 0.0312 . 801 ... 8 . ()0809 . 01094 . 826
. 9 . 00067 . 00351 . 902 , 9 , 0.0848 . ()1134 . 928
1. 0 | 1. O0106 | 1. O0390 1. 002 3. 0 | 1. 00887 | 1. 0.1173 3. 030
... 1 . 001.45 . 0.0429 ... 103 ... 1 . 00927 . 01213 . 132
... 2 . 00184 . 00468 . 203 ... 2 . 00966 . 01252 . 234
... 3 . 00223 . 00507 . 304 ... 3 . 01006 . 01292 . 337
. 4 . 00261 . 0.0546 . 405 ... 4 , 01045 . 01331 . 439
... 5 . 00300 . 00:585 . 506 . 5 . 01084 . 01371 . 542
... 6 . 00339 . 0.0624 . 607 ... 6 . 01124 . 01410 . 644
... 7 . 00378 . 0.0663 . 708 ... 7 . 01163 . 01450 . 747
... 8 . 004.17 . 00702 . 809 ... 8 . O1203 . 0.1490 . 850
. 9 . 00456 . 00741 . 911 . 9 . 01243 . 01529 . 953
1 NBS Circular C19, 6th ed., table 39, p. 55 (1924).
2 NBS Circular C19, 6th ed., table 29 (1924).
3 J. Domke, Z. ver, deut. Zuckerind. 62, 306 (1912); O. Schrefeld, p. 312.
4 The apparent Brix, that is, grams of sucrose dry Substance per 100 g of Solution, weighed with brass
weights in air, is approximately 0.01 percent gréâter than the true Brix in column 1.
Polarimetry, Saccharimetry, and the Sugars
633
TABLE 114.—Bria, apparent density, apparent specific gravity, and grams of sucrose
per 100 ml of sugar solutions—Continued
zt. Li L' 3.IIl Percent- w
... Apparent Anºt G. f sº j'. Apparent * º f
“º ºf g; pººl ||º ºf gº, pººl
Yº 20° C/20° C. in º ( § 20° C/20° C in ºlo
1 2 3 4 1 2 3 4
4. 0 | 1. 0.1282 | 1. 0.1569 4. 056 9. 0 | 1. 03297 | 1. 03590 9. 306
. 1 . 01322 . 01609 . I 59 ... 1 . 03338 . 03631 . 413
... 2 . 0.1361 , 01649 . 262 ... 2 . 03379 . 03672 . 521
. 3 . 01401 . 01688 . 365 . 3 . 03420 . 03713 . 628
. 4 . 0.1441 . 01728 . 468 . 4 . 03461 . 03755 . 735
. 5 . 0.1480 . 01768 . 571 . 5 . 03503 . 03796 . 843
... 6 . 01520 . 01808 . 675 ... 6 . 03544 . 03837 . 950
... 7 . 01560 . 01848 . 778 ... 7 , 0.3585 . 03879 10. 0.58
... 8 . 01600 . 01888 . 882 ... 8 . 03626 . 03920 . 166
. 9 . 01640 . 01928 . 986 . 9 . 03667 . 03961 . 274
5. 0 | 1. 01680 | 1. 01968 5. 089 10. 0 | 1, 03709 | 1. 04003 10. 381
. 1 . 01719 . 02008 . 193 . 1 . 03750 . 04044 . 489
... 2 . 01759 . 02048 . 297 ... 2 . 037.91 . 04086 . 597
... 3 . 01799 . 02088 . 401 . 3 . 03833 . 04127 . 706
. 4 . 01839 . 02128 . 506 . 4 . 03874 . 04169 . 814
. 5 , 0.1879 | . 02168 . 609 . 5 . 03916 . 04210 . 922
... 6 . 01919 . 02208 . 713 ... 6 , 0.3957 . 04252 11. 031
... 7 . 01959 . 02248 ... 818 . 7 , 0.3999 . 04293 . 139
... 8 . 01999 . 02289 . 922 . 8 || 1. 04040 . 04335 . 248
. 9 . 02040 . 02329 6. 027 . 9 , 0.4082 . 04377 . 356
6. 0 | 1. 02080 | 1. 02369 6. 131 11. 0 | 1. 04123 | 1. 04418 11. 465
. 1 . 02120 . 02409 . 236 ... 1 . 041.65 . 04460 . 574
... 2 . 02160 . 02450 . 340 ... 2 . 04207 . 04502 . 683
... 3 . 02200 . 02490 . 445 . 3 . 04248 . 04544 ... 792
... 4 . 0.2241 . 02:530 . 550 . 4 . 04290 . 04585 . 901
. 5 . 02281 . 02571 . 655 . 5 . 04332 . 04627 12. 010
... 6 . 02321 . 0.2611 . 760 ... 6 . 04:373 . 04669 . 120
7 . 02362 . 02652 . 865 . 7 . 04415 . 04711 . 229
. 8 . 02402 . 02692 . 971 ... 8 . 04457 . 04753 . 338
. 9 . 02442 . 02733 7. 076 . 9 , 0.4499 . 04795 . 448
7. 0 | 1. 02483 | 1. 02773 7. 181 12. 0 | 1, 04541 | 1.04837 12. 558
. 1 . 0.2523 . 02814 . 287 ... 1 . 04583 . 04879 . 667
... 2 . 0.2564 . 02854 . 392 ... 2 . 04625 . 04921 . 777
... 3 . 02604 . 02895 . 498 . 3 . 04667 . 04963 . 887
. 4 . 02645 . 20936 . 604 ... 4 . 04709 | 1. 05005 . 997
. 5 . 02685 . 02976 . 709 . 5 . 04750 . 05047 13. 107
... 6 . 02726 . 03017 ... 815 ... 6 . 04793 . 05090 . 217
... 7 . 02766 . 03058 . 921 ... 7 . 04835 . 05132 . 327
... 8 . 02807 . 03098 8. 027 ... 8 . 04877 . 05174 . 438
, 9 . 02848 . 03139 . 133 . 9 . 04919 . 05216 . 548
8. 0 | 1. 02888 | 1. 03180 8, 240 13. 0 | 1. 04961 | 1. 05259 13. 659
. 1 . 02929 . 0.3221 , 346 . 1 | 1. 05003 . 05301 . 769
... 2 . 02970 . 03262 . 452 ... 2 . 05046 . 05343 . 880
. 3 . 03011 . 03303 . 559 ... 3 . 05088 . 05386 . 991
. 4 . 03052 . 03344 . 665 ... 4 . 05130 . 0.5428 14. 102
. 5 . 03093 . 03385 . 772 . 5 05172 . 05470 . 213
... 6 . 03133 . 03426 . 879 ... 6 . 05:215 . 05513 . 324
... 7 . 03174 . 03467 . 985 ... 7 . 05257 . 05556 . 435
... 8 . 03:215 . 0.3508 9. 092 ... 8 . 05300 . 05598 . 546
. 9 . 03256 . 03549 . 199 | . 9 . 05342 . 05641 . 657
634
Circular of the National Bureau of Standards
TABLE 114.—Bria, apparent density, apparent specific gravity, and grams of sucrose
per 100 ml of sugar solutions—Continued
rCent- S - 3.I.O.S
i. .. Apparent Anºt º f ...”. Apparent Aºi." G. f
º se º dº. at º at: P. ºl crose º dº at gº at pº º
§ 20° C/20° C. in ºlo Yº - 20° C/20° C in jo
1 2 3 4 1 2 3 4
14. 0 | 1. 05385 | 1. 0.5683 14. 769 19. 0 | 1. 07549 | 1. 07853 20. 454
. 1 . 05427 . 05726 . 880 . 1 . 07593 . 07898 . 570
... 2 , 05470 . 05769 . 992 ... 2 . 07637 . 07942 . 686
... 3 . 05512 . 05811 15. 103 . 3 . 0.7681 . 0.7986 . 803
... 4 , 05555 . 0.5854 215 ... 4 07725 | 1. 08030 . 919
. 5 . 0.5598 . 05897 327 . 5 . 07769 , 08075 21. 036
... 6 . 05640 . 05940 . 439 ... 6 . 0.7814 . 0.8119 . 152
... 7 . 0.5683 . 05982 551 7 , 07858 . 08164 . 269
... 8 05726 | 1. 06025 . 663 ... 8 . 07902 . 08208 . 385
. 9 , 0.5768 . 06068 . 775 . 9 . 0794.7 , 0.8252 . 502
15. 0 | 1. 05811 | 1. 06111 15. 887 20. 0 | 1. 07991 | 1. 08297 21. 619
. 1 . 05854 . 06154 16, 000 . 1 | 1. 08035 . 08342 . 736
... 2 05897 . 06197 112 ... 2 08080 . 0.8386 . 853
... 3 05940 . 06240 . 225 . 3 . 0.8124 . 0.8431 . 971
... 4 . 05983 . 06283 . 338 ... 4 . 08169 . 08475 22. 088
. 5 | 1. 06026 . 06326 . 450 . 5 . 08213 . 08520 . 205
... 6 . 06069 . 06369 . 563 ... 6 . 08258 . 0.8565 . 323
... 7 . 061 12 . 06412 , 676 7 . 08302 . 08609 . 440
... 8 06155 . 06455 789 ... 8 . 08347 . 08654 . 558
. 9 . 06198 . 06499 , 902 . 9 08392 . 08699 . 676
16. 0 || 1, 06241 1. 06542 17, 0.15 21. 0 | 1. 08436 | 1. 08744 22. 794
. 1 06284 . 06585 . 129 . 1 . 08481 . 08789 . 912
... 2 06327 . 06629 . 242 ... 2 . 08526 . 08834 23. 030
... 3 , 06370 . 06672 . 356 . 3 . 0.857.1 . 08879 . 148
... 4 . 06414 . 06715 . 469 . 4 . 08616 . 08923 . 266
. 5 06457 . 06759 . 583 . 5 . 0.8660 . 0.8968 . 385
... 6 . O6500 . 06802 . 697 ... 6 . 08705 | 1. 09013 . 503
... 7 . 06544 . 0684.5 ... 810 7 , 08750 . 09058 . 622
... 8 . 06:587 . 06889 . 924 ... 8 . 08795 . 09.103 . 740
. 9 . 06630 . 06933 18. 038 . 9 . 08840 . 09 149 . 859
17. 0 | 1. 06674 | 1. 06976 18. 152 22, 0 | 1. 08885 | 1. 09.194 23. 978
... 1 06717 | 1. 07020 . 267 . 1 . 08930 . 09239 24. 097
... 2 . 06761 . 07063 . 381 ... 2 . 08975 . 09.284 216
... 3 . 06804 . 07107 . 495 . 3 | 1. 09020 . 09.329 . 335
... 4 . 06848 . 0715.1 . 610 ... 4 . 09066 . 09375 454
. 5 . 06891 . 07194 . 724 . 5 . 09111 . 09420 573
... 6 . 06935 . 07238 . 839 ... 6 . 09 156 . 09465 . 693
... 7 , 06978 . 07282 . 954 7 . 09.201 . 095.11 812
. 8 | 1. 07022 . 07325 19. 069 ... 8 . 09.247 . 09556 . 932
. 9 07066 . 07:369 . 184 . 9 . 09.292 . 0.9602 25. 052
18, 0 | 1. 07110 | 1. 07413 19. 299 23. 0 | 1. 09337 | 1. 09647 25. 172
... 1 . 07153 . 07457 414 . 1 . 09.383 . 0.9693 292
... 2 . 071.97 . 07501 . 529 . 2 . 09428 . 09738 412
... 3 . 07241 . 07545 644 . 3 . 09473 . 09784 . 532
. 4 07285 07589 . 760 . 4 . 09519 . 09829 . 652
. 5 . 07329 . 07633 . 875 . 5 . 09564 . 0.9875 . 772
... 6 . 07373 07677 . 991 ... 6 . 0.9610 . 0992.1 . 893
... 7 . 074.17 . 07721 20. 107 ... 7 . 0.9656 | 1. 0.9966 26. 013
... 8 . 07461 . 07765 . 222 ... 8 . 09701 | 1. 10012 . 134
. 9 . 07505 . 07S09 . 338 . 9 . 0.9747 ... 10058 . 255
Polarimetry, Saccharimetry, and the Sugars
635
TABLE 114.—Bria, apparent density, apparent specific gravity, and grams of sucrose
per 100 ml of sugar solutions—Continued


- 3.IIlS Percent- Iſa IIIS
*::::: Apparent Anºt º f sº of Su- Apparent * º f
tº ºf g; pººl || “...º dº,” g; |Pºll
Yº 20° C/20° C in º §§ 20° C/20° C in tºo
1 2 3 4 1 2 3 4
24. 0 | 1. 09792 | 1. 10.104 26. 375 29. 0 | 1. 12119 | 1. 12436 32. 545
. 1 . 09838 ... 10149 . 496 . 1 . 12166 . 12484 . 671
... 2 . 0.9884 . 10195 . 617 ... 2 . 12214 . 12532 . 797
. 3 . 09930 ... 10241 . 738 ... 3 . 12261 . 12579 . 923
. 4 . 0.9976 ... 10287 . 860 ... 4 . 12308 . 12627 33. 049
. 5 | 1. 10021 ... 10333 . 981 . 5 . 12356 . 12674 . 176
... 6 . 1006.7 ... 10379 27. 102 ... 6 . 12404 . 12722 . 302
... 7 . 101.13 . 10425 . 224 ... 7 . 12451 . 12770 . 429
... 8 ... 101.59 ... 10471 . 345 ... 8 . 12499 . 12817 . 556
, 9 ... 10205 ... 10517 . 467 . 9 , 12546 . 12865 . 683
25. 0 | 1. 10251 | 1. 10564 27. 589 30. 0 | 1. 12594 | 1. 1291.3 33. 810
. 1 ... 10297 ... 10610 . 710 . 1 . 12642 . 12961 . 937
... 2 ... 10343 ... 10656 . 833 ... 2 . 12690 | 1. 13009 34. 064
. 3 . 10389 ... 10702 . 955 ... 3 . 12737 . 13057 . 191
. 4 . 10435 ... 10748 28. 077 ... 4 . 12785 . 13105 . 318
. 5 . 10482 ... 10795 . 199 . 5 . 12833 . 13153 . 446
... 6 ... 10528 ... 10841 . 322 ... 6 . 1288.1 . 1320.1 . 574
... 7 . 10574 . 10887 . 444 ... 7 . 12929 . 13249 . 701
... 8 ... 10620 . 10934 . 567 ... 8 . 12977 . 13297 . 829
. 9 ... 10667 ... 10980 . 690 . 9 | 1. 13025 . 13345 . 95.7
26. 0 | 1. 10713 | 1. 11027 28. 813 31, 0 | 1, 13073 | 1. 13394 35. 085
. 1 . 10759 . 11073 . 935 . 1 . 13121 . 13442 . 213
... 2 ... 10806 . 11120 29. 059 ... 2 . 13169 . 13490 . 341
... 3 ... 10852 . 11166 . 182 ... 3 . 13217 . 13538 . 470
. 4 ... 10899 . 11213 . 305 ... 4 . 13266 . 13587 . 598
. 5 . 10945 . 11260 . 428 . 5 . 13314 . 13635 . 727
... 6 ... 10992 . 11306 . 552 ... 6 . 13362 . 13683 . 855
. 7 | 1. 11038 . 11353 . 675 ... 7 . 13410 . 13732 . 984
... 8 . 11085 . 11400 ... 799 ... 8 . 13459 . 13780 36. 113
. 9 . 11131 . 11447 . 923 . 9 . 13507 . 13829 . 242
27. 0 | 1. 11178 | 1. 11493 30. 046 32. 0 | 1. 13555 | 1. 13877 36. 371
. 1 . 11225 . 11540 . 170 . 1 . 13604 . 13926 . 500
... 2 , 11272 , 11587 , 294 ... 2 . 13652 , 13974 . 630
... 3 . 11318 . 11634 . 418 . 3 . 13701 | 1. 14023 . 759
... 4 . 11365 . 1 1681 . 543 . 4 . 13749 . 14072 . 889
. 5 . 11412 . 11728 . 667 . 5 . 13798 . 14120 37. 018
... 6 . 11459 . 11775 ... 792 ... 6 . 13846 . 14169 . 148
... 7 . 11506 . 11822 . 916 ... 7 . 13895 . 14218 . 278
... 8 . 11553 . 11869 31. 041 ... 8 . 13944 . 14267 . 408
. 9 . 11600 . 1 1916 . 165 . 9 . 13992 . 14316 . 538
28. 0 | 1. 11647 | 1. 1 1963 31, 290 33. 0 | 1. 14041 | 1. 14364 37. 668
. 1 . 11694 | 1. 12010 . 415 . 1 . 14090 . 14413 ... 798
... 2 . 11741 . 12058 . 540 ... 2 . 14139 . 14462 . 929
. 3 . 11788 . 12105 . 666 ... 3 . 14.188 . 14511 38. 059
. 4 , 11835 . 1215.2 . 791 ... 4 . 14236 . 14560 . 190
. 5 . 11882 . 12199 . 916 . 5 . 14285 . 14609 . 320
... 6 . 11929 . 12247 32. 042 ... 6 . 14334 . 14658 . 451
7 . 11977 . 12294 . 167 ... 7 . 14383 . 14708 . 582
. 8 | 1. 12024 . 12341 , 293 ... 8 . 14432 . 14757 . 713
. 9 . 12071 . 12389 . 419 . 9 . 14481 . 14806 . 844
636
Circular of the National Bureau of Standards
TABLE 114.—Bria, apparent density, apparent specific gravity, and grams of sucrose
per 100 ml of sugar solutions—Continued
Percent- }ram -
age . Su- || Apparent Ap º º f ..º. Apparent App arent º f
crose by density at . ºt per 100 ml crose by density at º, per 100 ml
weight O ; ð6% weight weight o gº weight
(Brix) 1I] W3CU10 (Brix) II]. Vactl()
1 2 3 4 1 2 3 4
34 0 | 1. 14530 | 1. 14855 38. 976 39. 0 | 1. 17030 | 1. 17362 45, 682
. 1 . 14580 . 14904 39. 107 . 1 . 17081 . 17413 , 8.19
. 2 . 14629 . 14954 . 239 ... 2 . 17132 . 17464 . 956
, 3 . 14678 | 1. 1 5003 . 370 ... 3 . 17183 . 17515 46. 094
. 4 . 14727 . 15052 . 502 ... 4 . 17234 . 17566 , 231
. 5 . 14776 . 15102 . 634 . 5 . 17285 . 17618 , 369
... 6 . 14826 . 15151 . 767 ... 6 . 17336 . 17669 , 506
... 7 . 14875 . 15201 . 898 7 . 17387 . 17720 . 644
... 8 . 14925 . 15250 40. 030 ... 8 . 17439 . 17772 , 782
. 9 . 14974 . 15300 . 162 . 9 . 17490 . 17823 . 920
35. 0 | 1. 15024 | 1. 15350 40. 295 40. 0 | 1. 17541 | 1. 17874 47, 058
. 1 . 15073 . 15399 . 427 40. 1 593 926 . 196
... 2 . 15123 . 15449 . 560 40. 2 644 | 1. 17977 . 334
. 3 . 15172 . 15498 . 692 40. 3 695 | 1, 18029 , 473
... 4 . 15222 . 15548 . 825 40. 4 747 080 ... 611
. 5 . 15271 . 15598 . 958 40. 5 | 1. 17798 || 1. 18132 . 750
... 6 . 15321 . 15648 41. 0.91 40. 6 849 183 47. 889
... 7 . 15371 . 15698 . 224 40. 7 901 235 48. 028
... 8 . 15420 . 15747 . 358 40. 8 || 1. 17953 287 . 167
. 9 . 15470 . 15797 . 491 40. 9 || I. 18004 339 . 306
36. 0 | 1. 15520 | 1. 15847 41. 625 41. 0 | 1. 18056 | 1. 18390 48. 445
. 1 . 15570 . 15897 . 758 41. I 107 442 . 585
... 2 . 15620 . 15947 . 892 41. 2 1.59 494 . 724
. 3 . 15669 . 15597 42. 026 41. 3 211 546 . 864
. 4 . 15719 | 1. 16047 . 160 41. 4 263 598 49. 004
. 5 . 15769 . 16098 . 294 41. 5 | 1. 18314 | 1. 18650 . 143
... 6 . 15819 . 16148 . 428 41. 6 356 702 . 283
... 7 . 15869 . 16198 . 562 4I. 7 418 754 . 424
... 8 . 15919 . 16248 . 697 4.1. 8 470 806 . 564
. 9 . 15970 . 16298 . 831 41. 9 522 858 . 704
37. 0 | 1. 16020 | 1. 16349 42. 966 42. 0 | 1. 18574 | 1. 18910 49. 845
... 1 . 16070 . 16399 43. 100 42. 1 626 | 1. 18962 49. 985
... 2 . 16120 . 16449 . 235 42. 2 678 | 1. 19014 50. 126
... 3 . 16170 . 16500 . 376 42. 3 730 062 . 267
. 4 . 16221 . 16550 . 500 42. 4 782 119 50. 408
. 5 . 16271 . 16601 . 645 42. 5 | 1. 18835 | 1. 19171 . 549
... 6 . 16321 . 16651 . 771 4.2. 6 S87 224 . 690
... 7 . 16372 . 16702 . 911 42. 7 939 276 . 831
... 8 . 16422 . 16752 44. 047 42 8 991 329 50. 973
. 9 . 16473 . 16803 . 182 42, 9 | 1. 19044 381 51. 114
38. 0 | 1. 16523 I. 16853 44, 318 43. 0 | 1. 19096 | 1. 19434 51. 256
... 1 . 16574 . 16904 454 43. 1 148 486 . 398
... 2 . 16624 . 16955 . 590 43. 2 201 539 . 539
... 3 . 16675 | 1. 17006 . 726 43. 3 253 591 . 681
. 4 . 16726 . 17056 . 862 43. 4 306 644 . 824
. 5 . 16776 . 17107 . 999 43. 5 | 1. 19358 | 1. 19697 51. 966
... 6 . 16827 . 17158 45. 135 43. 6 411 749 52. 108
... 7 . 16878 . 17209 272 43. 7 483 802 . 251
... 8 . 16929 . 17260 . 408 43. 8 516 855 . 393
. 9 . 16979 . 17311 . 545 43. 9 569 908 . 536
Polarimetry, Saccharimetry, and the Sugars
637
TABLE 114.—Briz, apparent density, apparent specific gravity, and grams of sucrose
per 100 ml of sugar solutions—Continued
... Apparent Anºt º f ...'...'. Apparent Aºt º f
jºy | dºg" |gºt | Pººl || “... ºat g; pººl
§ 20° C/20° C. in º § 20° C/20° C in º
I 2 3 4 1 2 3 4
44. 0 | 1. 19622 | 1. 1996.1 5.2. 679 49. 0 | 1. 22306 | 1. 22652 59. 980
44. 1 674 | 1. 20013 . 822 49. 1 360 707 60. 129
44. 2 727 066 52. 965 49. 2 415 762 . 279
44. 3 780 119 53. 108 49. 3 470 817 . 428
44. 4 833 172 . 252 49. 4 525 872 . 578
44. 5 | 1. 19886 | 1. 20226 . 395 49. 5 | 1. 22580 1. 22927 . 728
44. 6 939 279 . 539 49. 6 634 1 22982 60. 878
44. 7 992 332 . 683 49. 7 689 1. 23037 61. 028
44. 8 | 1. 2004.5 385 . 826 49. 8 744 092 . 178
44. 9 098 438 53. 970 49. 9 799 147 61. 328
45. 0 | 1. 20151 | 1. 20491 54. 114 50, 0 | 1. 22854 | 1. 23202 61. 478
45. 1 204 545 . 259 50. 1 909 | 1. 23257 . 629
45. 2 257 598 . 403 50. 2 | 1. 22964 313 . 780
45. 3 311 651 . 547 50. 3 | 1. 23019 368 . 930
45. 4 364 705 . 692 50. 4 074 423 62. 081
45. 5 | 1. 20417 | 1. 20758 . 837 50. 5 | 1. 23130 | 1. 23478 . 232
45. 6 470 812 54. 981 50. 6 185 534 . 383
45. 7 524 865 55. 126 50. 7 240 589 . 535
45. 8 577 919 . 272 50. 8 295 645 . 686
45. 9 630 | 1. 20972 . 417 50. 9 351 700 . 838
46. 0 | 1. 20684 | 1. 21026 55. 562 51. 0 | 1. 23406 | 1. 23756 62. 989
46. 1 737 080 . 708 51. 1 461 811 63. 141
46. 2 791 133 . 853 51. 2 517 867 . .293
46. 3 845 187 55. 999 51. 3 572 922 . 445
46. 4 898 241 56. 145 51. 4 628 | 1. 23978 . 597
46. 5 | 1. 20952 | 1. 21295 . 291 51. 5 | 1. 23683 | 1. 24034 . 750
46. 6 | 1. 21006 349 . 437 51, 6 739 089 . 902
46. 7 059 402 . 583 51. 7 794 145 64. 055
46. 8 113 456 . 729 5.1. 8 850 201 . 208
46. 9 167 510 56. 876 51. 9 906 257 . 360
47. 0 | 1. 21221 | 1. 21564 57. 022 52. 0 || 1 23962 | 1. 24313 64. 513
47. 1 275 618 . 169 52. 1 | 1. 24017 369 . 666
47. 2 329 673 . 316 52. 2 07.3 425 . 820
47. 3 383 727 . 463 52. 3 129 481 . 973
47. 4. 437 781 57. 610 52.4 185 537 65. 127
4.7. 5 | 1. 21.491 | 1. 21835 57. 757 52. 5 | 1. 2424.1 | 1. 24593 65. 280
47. 6 545 889 57. 904 5.2. 6 297 649 . 433
47. 7 599 943 58. 052 52. 7 353 705 . 588
47. 8 653 | 1. 21998 , 199 52. 8 409 761 . 742
4.7. 9 707 | 1. 22052 . 347 52. 9 465 818 . 896
48. 0 | 1. 21761 | 1. 22106 58. 495 53. 0 | 1. 24521 | 1. 24874 66. 050
48. I 816 161 . 643 53. 1 577 930 . 205
48. 2 870 215 ... 791 53. 2 633 987 . 359
48. 3 924 270. 58. 939 53. 3 690 | 1. 25043 . 514
48. 4 979 324 59. 0.87 53. 4 746 099 . 669
48. 5 | 1. 22033 | 1. 223.79 . 236 53. 5 | 1. 24802 | 1. 251.56 . 824
48. 6 088 434 . 385 53. 6 858 212 . 979
48. 7 142 488 . 533 53. 7 915 269 67. 134
48. 8 197 543 . 682 53. 8 971. 325 . 290
48. 9 251 598 . 831 53. 9 | 1. 25028 382 . 445
323414°–42——42
3
2
638
Circular of the National Bureau of Standards
TABLE 114.—Briz, apparent density, apparent specific gravity, and grams of sucrose
per 100 ml of sugar solutions—Continued
Percent - Grams Per * GramS of
age of Su- || Apparent * º f sº §. Apparent * SUICTOSe
“º | *ś" gºi..., | Pººl || “...} | *.*.* g; Pººl
(Brix) 30° C20 c | mº, (Brix) 20°C/20°C i.o
1 2 3 4 1 2 3 4
54. 0 | 1. 25084 | 1. 25439 67. 601 59. 0 | 1. 27958 | 1. 28320 75. 555
54. 1 141 495 . 757 59. 1 | 1. 28017 379 718
54. 2 197 552 . 912 59. 2 0.75 437 . 880
54. 3 254 609 68. 069 59. 3 134 497 76. 043
54. 4 311 666 . 225 59. 4 193 556 . 207
54, 5 | 1. 25367 | 1. 25723 . 381 59. 5 251 614 . 369
54. 6 424 780 . 537 59. 6 309 672 . 533
54. 7 481 836 . 694 59. 7 367 731 . 696
54, 8 538 893 . 851 59. 8 426 789 . 860
54. 9 594 950 69. 008 59. 9 485 849 77. 024
55. 0 | 1. 25651 | 1. 26007 69. 164 60. 0 | 1. 28544 | 1. 28908 77. 188
55. 1 708 064 . 322 60. 1 602 966 351
55. 2 765 122 . 479 60. 2 661 | 1. 29025 515
55. 3 822 179 . 636 60. 3 720 084 . 680
55. 4 879 236 . 794 60. 4 779 143 . 844
55. 5 | 1. 25936 | 1. 26.293 69. 951 60. 5 838 203 78. 009
55. 6 | 1. 25993 350 70. 109 60. 6 897 262 . 173
55. 7 | 1. 26050 408 . 267 60. 7 956 321 . 338
55. 8 108 465 . 425 60. 8 || 1. 290.15 380 . 503
55. 9 165 522 . 583 60. 9 074 439 . 668
56. 0 | 1. 26.222 | 1. 26.580 70, 742 61. 0 | 1. 29.133 | 1. 29498 78. 833
56. 1 279 637 70. 900 61. 1 193 559 . 999
56. 2 337 695 71. 0.59 61. 2 252 618 79. 165
56. 3 394 752 . 217 61. 3 311 677 . 330
56. 4 452 810 . 376 61. 4 370 736 . 496
56, 5 | 1. 26509 | 1. 26868 . 535 61. 5 430 796 . 662
56. 6 566 925 . 694 61. 6 489 855 . 828
56, 7 624 | 1. 26983 71. 854 61. 7 548 915 . 995
56. 8 682 | 1. 27041 72. 013 61. 8 608 975 80. 161
56. 9 739 098 . 173 61. 9 667 | 1. 30034 . 328
57. 0 | 1. 26797 | 1. 271.56 72. 332 62. 0 | 1. 29.726 | 1. 30093 80. 494
57. 1 854 214 . 492 62. 1 786 153 . 661
57. 2 912 272 . 652 62. 2 845 212 . 828
57. 3 970 330 ... 812 62. 3 905 273 . 995
57. 4 || 1. 27028 388 72. 973 62. 4 966 334 81. 162
57. 5 | 1. 27086 | 1. 27446 73. 133 62. 5 | 1. 30025 393 . 329
57. 6 143 504 . .293 62. 6 0.85 453 . 497
57. 7 201 562 . 454 62. 7 145 513 . 665
57.8 259 620 . 615 62. 8 205 573 . 833
57. 9 317 678 . 776 62. 9 265 633 82. 001
58. 0 | 1. 27375 | 1. 27736 73. 937 63. 0 | 1. 30325 | 1. 30694 82. 169
58. 1 433 794 74. 098 63. 1 385 754 . 337
58. 2 492 853 . 260 63. 2 446 815 . 506
58. 3 550 911 . 421 63. 3 506 875 . 674
58. 4 608 || 1. 27969 . 583 63. 4 566 936 . 843
58. 5 | 1. 27664 | 1. 28028 . 744 63. 5 626 994 83. 012
58. 6 724 086 74. 906 63. 6 686 | 1. 31055 180
58. 7 782 145 75. 068 63. 7 747 117 350
58. 8 841 203 . 230 63. 8 807 177 . 519
58. 9 899 262 . 393 63. 9 867 237 , 688
Polarimetry, Saccharimetry, and the Sugars
639
TABLE 114.—Briz, apparent density, apparent specific gravity, and grams of sucrose
per 100 ml of sugar solutions—Continued
Pe cº- - ..I.T.S
ºil apparent º' º' |º. Apparent º' | *
tº déjàºt gºt | Pººl || “...; ºf gº, Pººl
(Érix) 3) C30° C º, #. 30° Cº. c || Y.
I 2 3 4 1 2 3 4
64. 0 | 1. 30927 | 1. 31297 || 83. 858 || 69. 0 | 1. 33992 | 1. 34371 92. 524
64. 1 988 359 84. 028 69. 1 | 1. 34054 433 . 701
64. 2 | 1. 31048 4.18 . 198 69. 2 116 495 . 878
64. 3 108 479 . 367 || 69. 3 179 558 || 93. 056
64. 4 169 540 | . 538 || 69.4 241 621 . 233
64. 5 229 600 | . 708 || 69. 5 304 684 | . 411
64. 6 290 661 . 879 || 69. 6 366 746 . 589
64. 7 350 723 85. 049 69. 7 429 809 . 767
64. 8 412 784 | . 220 || 69. 8 491 871 . 945
64. 9 473 845 . 391 69. 9 554 934 94. 123
65. 0 | 1. 31533 | 1. 31905 || 85. 561 || 70. 0 | 1. 34616 | 1. 34997 || 94. 302
65. 1 594 966 | . 733 || 70. 1 679 | 1. 35060 . 481
65. 2 655 | 1. 32028 . 904 || 70. 2 742 123 . 660
65. 3 716 089 86. 076 || 70. 3 805 186 . 839
65. 4 777 150 | . 248 || 70. 4 867 248 || 95. 017
65. 5 837 210 | . 419 || 70. 5 930 311 . 197
65. 6 898 271 . 591 70. 6 993 375 . 376
65. 7 959 332 . 763 || 70. 7 | 1. 35056 438 . 556
65. 8 || 1. 32019 393 . 935 70. 8 119 501 . 736
65. 9 08.1 455 | 87. 107 || 70. 9 182 564 | . 916
66. 0 | 1. 32142 | 1. 32516 87. 280 71. 0 | 1. 35245 | 1. 35627 96. 096
66. 1 203 577 | . 453 || 71. 1 308 691 . 276
66. 2 264 638 | . 626 || 71. 2 371 754 . 456
66. 3 325 699 | . 798 || 71. 3 434 817 . 636
66. 4 385 759 | . 971 || 71. 4 498 88.1 ... 817
66. 5 446 820 | 88. 142 || 71. 5 561 944 . 998
66. 6 509 884 | . 318 || 71. 6 625 | 1. 36008 || 97. 179
66. 7 570 945 . 492 || 71. 7 688 0.72 . 360
66. 8 632 | 1. 33007 | . 666 || 71. 8 751 135 . 541
66. 9 693 068 . 839 || 71.9 814 198 . 722
67. 0 | 1. 32754 | 1. 33129 | 89. 012 || 72. 0 | 1. 35877 | 1. 36261 | 97. 904
67. 1 816 192 . 187 72. 1 940 324 98. 085
67. 2 878 254 | . 361 || 72. 2 | 1. 36004 389 . 268
67. 3 939 315 | . 536 || 72. 3 067 452 . 449
67. 4 | 1, 33001 377 | . W 11 || 72. 4 131 516 . 632
67. 5 062 438 | . 885 || 72. 5 194 579 . 814
67, 6 124 500 90, 060 || 72. 6 258 643 . 997
67. 7 186 562 | . 235 || 72. 7 322 707 || 99. 179
67, 8 248 625 . 411 || 72.8 385 771 . 362
67. 9 309 686 | . 585 || 72. 9 450 836 . 545
68. 0 | 1. 33371 | 1. 33748 || 90. 761 || 73. 0 | 1. 36514 | 1.36900 | 99. 728
68. 1 433 810 | . 937 || 73. 1 578 964 | . 912
68. 2 495 872 91. 112 || 73. 2 642 | 1. 37028 100. 095
68. 3 557 935 | . 288 || 73. 3 705 092 . 278
68. 4 619 997 | . 464 || 73. 4 769 156 . 462
68. 5 681 | 1. 34059 . 641 || 73. 5 833 220 . 646
68. 6 743 121 ... 817 || 73. 6 896 283 . 827
68. 7 805 183 | . 993 || 73. 7 960 347 || 101. 014
68. 8 867 245 92. 169 || 73. 8 | 1. 37024 411 . 198
68. 9 930 309 | . 347 || 73. 9 088 476 . 383
640
Circular of the National Bureau of Standards
TABLE 114.—Briz, apparent density, apparent specific gravity, and grams of sucrose
per 100 ml of sugar solutions—Continued

Percent- DOl º II]
. . Su- || Apparent * º f ..º. Apparent * º f
tº ºf g; pººl ||º ºf g; pººl
#. 20° C/20° C in jo § 20° C/20° C in *.
I 2 3 4 I 2 3 4
74. 0 | 1. 371.53 | 1. 37541 || 101, 568 79. 0 | 1. 40409 | 1. 40806 || 111. 002
74. 1 217 605 . 753 79. 1 475 872 . 195
74. 2 281 669 . 937 79. 2 541 938 . 388
74. 3 345 733 || 102. 122 79. 3 607 | 1. 41005 . 581
74. 4 410 798 . 308 79. 4. 674 072 . 775
74. 5 475 864 . 493 79. 5 740 138 . 968
74. 6 539 928 . 679 79. 6 806 204 || 112. 161
74. 7 604 993 . 865 79. 7 872 270 . 354
74, 8 668 || 1. 38057 | 103. 050 79. 8 939 337 . 549
74. 9 733 122 . 237 79. 9 || 1. 41005 404 . 743
75. 0 | 1. 37797 | 1. 38.187 | 103. 423 80. 0 | 1. 41072 | 1. 41471 || 112. 938
75. 1 862 252 . 609 , 80. 1 138 537 || 113. 131
75. 2 926 316 ... 796 80. 2 204 603 . 326
75. 3 991 381 . 983 80. 3 271 670 . 521
75. 4 055 445 || 104. 170 80. 4 337 737 . 715
75. 5 | 1. 38119 | 1. 38510 || 104, 356 80. 5 404 804 . 911
75. 6 184 575 . 543 80. 6 472 872 | 114. 106
75. 7 249 640 . 731 80. 7 537 937 . 301
75. 8 314 705 . 919 80. 8 604 | 1. 42004 . 497
75. 9 379 7.70 | 105. 106 80. 9 671 0.72 . 692
76. 0 | 1. 38444 | 1. 38835 | 105. 294 81. 0 | 1. 41737 | 1.42138 || 114. 888
76. 1 510 902 . 482 81. 1 804 205 || 115. 084
76. 2 575 967 . 670 81. 2 871 272 . 280
76. 3 640 | 1. 39032 . 859 81. 3 938 339 . 477
76. 4 705 097 || 106. 047 81. 4 | 1. 42005 906 . 673
76. 5 770 162 . 236 81. 5 0.72 474 . 870
76. 6 835 228 . 424 81. 6 139 541 || 116. 067
76. 7 900 293 6.13 81. 7 206 608 . 264
76. 8 965 358 . 802 81. 8 273 675 . 461
76. 9 | 1. 39030 423 . 991 81. 9 340 742 . 658
77. 0 | 1. 39096 | 1. 394.89 || 107. 181 82. 0 | 1. 42407 | 1. 42810 | 116. 856
77. 1 161 554 . 370 82. 1 475 878 || 117. 053
77. 2 225 619 . 560 82. 2 543 946 . 252
77. 3 291 685 . 750 82. 3 610 | 1. 43013 . 449
77. 4. 356 750 . 940 82.4 677 080 ... 647
77. 5 422 816 || 108. 130 82. 5 744 148 . 845
77. 6 488 882 . 320 82. 6 81 J. 214 || 113. 044
77.7 554 949 . 511 82. 7 878 282 . 243
77.8 619 | 1. 40014 . 701 82. 8 946 350 . 442
77. 9 685 080 . 892 82.9 | 1. 43013 417 . 641
78. 0 | 1. 39.751 | 1. 401.46 || 109. 084 83. 0 | 1. 43081 | 1. 43486 || 118. 840
78. 1 816 211 . 274 83. 1 148 553 | 119. 039
78. 2 882 277 . 466 83. 2 216 621 . 239
78. 3 948 344 . 657 83. 3 283 688 . 438
78.4 | 1. 40013 409 . 848 83. 4 351 756 . 638
78. 5 079 475 | 110. 041 83. 5 419 824 . 838
78. 6 145 541 . 232 83. 6 488 894 | 120. 039
78. 7 211 607 . 425 83. 7 555 961 . 238
78. 8 277 674 , 617 83. 8 623 1. 44029 . 439
78, 9 343 740 . 809 83. 9 691 097 . 640
Polarimetry, Saccharimetry, and the Sugars
641
TABLE 114.—Bria, apparent density, apparent specific gravity, and grams of sucrose
per 100 ml of sugar solutions—Continued


*I] [.- Grams of Percent- *
...; ". Apparent * SUlCrOSé age . i. Apparent Anºt ‘. f
crose º density at gravity at P.*ºl ‘. § º, at gº at P. § Fl
Yº 20° C/20° C. in º §§ 20° C/20° C in º
1 2 3 4 } 2 3 4
84. 0 | 1. 43758 || 1. 44.165 | 120. 841 89. 0 | 1. 47199 || 1. 47616 || 131. 096
. 1 . 43826 . 44234 | 121. 042 . 1 . 47269 . 47686 . 305
... 2 . 43894 . 44302 . 243 ... 2 . 47339 . 477.56 . 515
. 3 . 43962 . 44370 . 444 . 3 . 47409 . 47826 . 725
. 4 | 1.44030 . 44438 . 646 . 4 . 47479 . 47897 . 935
. 5 . 44098 . 44507 . 847 . 5 . 47548 . 47967 || 132. 145
... 6 . 44.166 . 44575 | 122. 049 ... 6 . 47618 | 1. 48037 . 355
. 7 . 44234 . 44643 . 251 ... 7 . 47688 . 48107 . 565
... 8 . 44303 . 4471.2 . 453 ... 8 . 477.58 . 48.177 . 776
. 9 . 44371 . 44780 . 655 . 9 . 47828 . 48247 . 987
85. 0 | 1. 44439 | 1. 44848 || 122. 858 90. 0 | 1. 47898 || 1. 48317 | 133. 198
. 1 . 44507 . 44917 | 123. 061 . 1 . 47968 . 48388 . 409
... 2 . 44576 . 44985 . 263 . 2 | 1. 48039 . 48458 . 620
. 3 . 44644 | 1. 45054 . 466 . 3 . 48109 . 48529 . 832
. 4 . 44712 . 45123 . 670 . 4 . 48179 . 48599 || 134. 043
. 5 . 44781 . 45.191 . 873 ... 5 . 48249 . 48669 . 255
... 6 . 44849 . 45260 | 124. 0.76 ... 6 . 483.20 . 48740 . 467
... 7 . 44918 . 45329 . 280 ... 7 . 48390 . 488.10 . 680
... 8 . 44986 . 45397 . 484 ... 8 . 48460 . 4888.1 . 892
. 9 | 1. 45055 . 45466 . 688 . 9 . 48531 . 48951 | 135. 104
86. 0 | 1.45124 | 1. 45.535 | 124, 892 91. 0 | 1. 48601 | 1. 49022 || 135. 317
. 1 . 45.192 . 45604 || 125. 096 . 1 . 48672 . 49093 . 530
... 2 . 45261 . 45673 . 301 ... 2 . 48742 . 49164 . 743
. 3 . 45330 . 45741 . 505 ... 3 . 48813 . 49234 . 956
... 4 . 45398 . 45810 . 710 . 4 . 48883 | . 49305 || 136. 170
. 5 . 454.67 . 45879 . 915 . 5 . 48954 . 493.76 . 383
... 6 . 45536 . 45949 || 126. 121 . 6 | 1. 49024 . 49447 . 597
... 7 . 45605 | 1.460.18 . 326 ... 7 . 49095 . 49518 . 811
... 8 . 45674 . 46087 . 531 ... 8 . 49166 . 495.88 || 137. 025
. 9 . 457.43 . 46156 . 737 . 9 . 49236 . 49659 . 239
87. 0 | 1. 45812 | 1. 46225 | 126. 943 92. 0 | 1. 49307 | 1. 49.730 | 137. 454
. 1 . 45881 . 46294 | 127. 149 . 1 . 493.78 . 49801 . 668
... 2 . 45950 . 46364 . 355 ... 2 . 49449 . 4987.2 . 883
. 3 | 1. 46019 . 46433 . 562 . 3 . 49520 . 49944 || 138. 098
. 4 . 46088 . 46502 . 768 ... 4 . 49591 | 1. 50015 . 313
... 5 . 46157 . 46572 . 975 . 5 . 49.662 . 50086 . 529
... 6 . 46227 . 46641 | 128. 182 ... 6 . 49733 . 50157 . 744
... 7 . 46296 . 46710 . 389 ... 7 . 49804 . 50228 . 960
... 8 . 46365 . 46780 . 596 ... 8 . 49875 . 50299 || 139. 176
. 9 . 46434 . 46849 . 803 . 9 . 49.946 . 50371 . 392
88. 0 | 1. 46504 | 1. 46919 | 129. 011 93. 0 | 1. 5.0017 | }. 50442 | 139, 608
... 1 . 46573 . 46989 . 219 . 1 . 50088 . 50513 . 824
... 2 . 46643 | 1. 47058 . 426 ... 2 . 50159 . 50585 140. 041
. 3 . 46712 . 47128 . 635 ... 3 . 50230 . 50656 . 257
. 4 . 46782 . 47198 . 843 . 4 . 50302 . 50728 . 474
... 5 . 46851 . 47267 130. 051 . 5 . 50373 . 50799 . 691
... 6 . 46921 . 47337 . 260 ... 6 . 50444 . 50871 . 908
7 . 46990 . 47.407 . 468 ... 7 . 50516 . 50942 | 1.41. 126
. 8 | 1. 47060 . 47477 . 677 ... 8 . 50587 | 1. 51014 . 343
. 9 . 471.30 . 47547 . 886 . 9 . 50659 . 51086 . 561
642
Circular of the National Bureau of Standards
TABLE 114.—Bria', apparent density, apparent specific gravity, and grams of sucrose
per 100 ml of sugar solutions—Continued


Percent- G f P t- Gra f
jº. Apparent App º º a.º. Apparent * º
º deº, at g; º t per } º CTOSe } deº, at g sº at per } Fl
Af 20° O no sº i - O © o Wel
Yº! 20° C/20° C inºo Y; 20° C/20°C in º
l 2 3 4 1 2 3 4
94. 0 | 1. 50730 | 1. 51157 | 1.41. 779 94. 6 | 1. 51160 | 1. 51588 | 1.43. 0.91
... I . 50802 , 51229 . 997 ... 7 . 51231 . 51660 . 310
... 2 . 50873 . 51301 | 1.42. 216 ... 8 . 51303 . 51732 . 529
. 3 . 50945 . 51372 . 434 . 9 . 51.375 . 51804 . 749
4 | 1. 51016 . 51444 . 653
5 . 51088 . 51516 . 872 95. 0 | 1. 5.1447 | 1. 51876 143. 968
TABLE 1.15.—Increase in volume when sucrose is dissolved in water at 20°C (g/100 ml)
[Eacample.—100 ml of water at 20°C is taken and 130 g of sucrose is dissolved
therein.
(column 4), the total volume being 100+ 81.465 = 181.465 ml]
The resultant solution at 20°C has increased in volume 81.465 ml
Weight Resultant solution Weight Resultant solution
of su- of su-
CI’OSé CIOSe
dis- dis-
solved Sucrose | Specific Increase || $olyºd | Sucrose | Specific | Increase
in 100 | by weight gravity in in 100 by weight gravity in
ml of (Brix) 20°/4°C | volume ml of (Brix) 20°/4°C volume
water water
I 2 3 4 1 2 3 4
g % ml g % - ml
5 4. 7699 || 1. 01694 3. 078 90 || 47. 4125 | 1. 21546 56. 174
10 9. 1055 | 1. 03446 6. 165 100 || 50. 0442 | 1. 22981 62. 483
15 13. 0635 | 1. O5093 9. 259 110 || 52. 4250 | 1. 24301 68. 802
20 | 16. 6912 | 1. 06645 12. 357 120 54. 5893 | 1. 25520 75. 130
25 | 20. 0283 | 1. 08109 15. 461
130 || 56. 5652 | 1. 26649 81. 465
30 23. 1083 | 1. 09491 18. 570 140 58. 3763 | 1. 27696 87. 808
35 25. 9599 || 1. 10799 21. 683 150 | 60. 0424 | 1. 28671 94. 157
40 28. 6075 | 1. 12037 24. 801 160 | 61. 5803 | 1. 29579 100. 513
45 31. 0723 | 1. 13212 27. 922 170 63. 0.042 | 1. 30429 || 106. 873
50 || 33. 3726 | 1. 14327 31. 048
180 | 64. 3263 | 1. 31225 | 113. 239
55 35. 5243 | 1. 15387 34. 177 190 65. 5572 | 1. 31972 | 119. 609
60 | 37. 5414 | 1. 16396 37. 310 200 | 66. 7059 | 1. 32675 | 125. 984
65 39. 4361 | 1. 17356 40. 447 210 || 67. 7805 | 1. 33337 132. 362
70 || 41. 2193 | 1. 18273 43. 587 220 | 68. 7880 | 1. 33961 || 138. 744
75 42. 9004 || 1. 19147 46. 729
230 69. 7343 | 1. 34551 | 1.45. 129
80 || 44, 4881 | 1. 19983 49. 874 240 || 70. 6249 | 1. 351 1 0 || 151. 517

Polarimetry, Saccharimetry, and the Sugars
643
TABLE 116.-Increase in volume when sucrose is dissolved in water at 20° C (pounds
avoirdupois per gallon)
Example—One gallon of water at 20° C is taken and 5 pounds of sugar
The resultant solution at 20° C has increased in
volume 0.373 gallon (column 4), the total volume being 1–H 0.373=1.373 gallons.
(sucrose) is dissolved therein.
Resultant solution
Resultant solution
Sucrose jº
dissolv- dissolv-
ed in 1 | Sucrose Specific | Increase ed in 1 | Sucrose Specific Increase
gal. Of y i + xr º gal. Of by - º
water | weight | #º I Il water | weight | º II]
(Brix) 20°/4° C volume (Brix) 20°/4° C | volume
1 2 3 4 1 2 3 4
lb gal lb gal
(avdp) | Percent (U. S.) (avdp) Percent (U. S.)
0. 1 1. 1862 1. 0028 0. 007 7 45. 6606 1. 2061 0. 523
... 2 2. 3443 1. 0074 . 015 8 48. 988.1 1. 2240 . 599
... 3 3. 4760 1. 0118 , 022 9 51. 9316 1. 2403 . 674
. 4 4. 5816 1. 0162 - ; 10 54. 5539 1. 2550 . 750
. 5 5. 6622 1. 0205 . 03
... 6 6. 7186 1. 0.247 044 11 56. 9049 1. 2684 . 826
... 7 7. 75.15 1. 0289 . 052 12 59. 0246 1. 2807 . 902
... 8 8. 7619 1. 0331 . 059 13 60. 9456 1. 2920 . 978
. 9 9. 7503 1. 0371 . 067 14 62. 6945 1. 3024 1. 055
15 64. 2935 1. 3121 1. 131
1. 10. 7175 1. 0411 . 074 16 65. 7611 1. 3210 1. 207
2 19. 3602 1. 0.781 . 148 17 67. 1128 1. 3292 1. 283
3 26. 4772 1. 1104 . 223 18 68. 36.18 1. 3370 1. 360
4 32. 4399 1. 1387 . 297 19 69. 5.194 1. 3442 1. 436
5 37. 5080 1. 1638 , 373 20 70. 5953 1. 3509 1. 513
6 4.1. 8688 1. 1861 . 448
644
Circular of the National Bureau of Standards
TABLE 117.-Weight per United States gallon and weight per cubic foot of sugar
(sucrose) solutions at 20° C.
[This table is based on the density values of Plato' for solutions of cane sugar.
The Baumé values are from the table of Bates and Bearce.”
for brass weights, density 8.4.
One pound (avoirdupois) 453.5924 g.
weighs 3,778.649 g (8.33049 pounds avoirdupois) in vacuo)
The weights are
One United States gallon, 231 cubic inches.
One United States gallon of water
Sucrose wº Specific | Specific
by Weight per Weight per cubic gravity, gravity, Baumé
weight gallon in air & gallon in vacuo & foot | 20°/4° C120°/20°C
(Brix) in air 3
lb g lb g lb -
() 8. 322 3774. 6 8. 330 3778. 6| 62. 25 0.998.23| 1. 00000 0. 00
| 8. 354 3789. 3| 8. 363. 3793. 3| 62. 49| 1. 00212| 1. 00389 . 56
2 8. 387 3804. 1 || 8. 395 3808. 1 || 62. 74| 1. 00602| 1. 00779 1. 12
3 8. 419. 3818, 9| 8. 428, 3822. 9| 62. 98 1. 00993| 1. 0.1172 1. 68
4 8. 452 3833. 9| 8. 461 || 3837. 9| 63. 23| 1. 01388 1. 0.1567 2. 24
5 8. 485| 3848. 9| 8. 494 3852. 9| 63. 48| 1. 0.1785| 1. 01965 2. 79
6 8. 519. 3864. 1ſ 8. 528, 3868. 1| 63. 73 1.02186 1. 02366 3. 35
7 8. 552 3879. 3| 8. 561| 3883. 3| 63. 98 1. 02588 1. 0.2770 3. 91
8 8. 586|| 3894. 7| 8. 595| 3898. 7| 64. 23| 1. 02994| 1. 03176 4. 46
9 8. 620 3910. 2 8. 629 3914. 2 64. 49| 1. 03403 1. 03586 5. 02
10 8. 655, 3925. 7 8. 664 3929. 7| 64, 74| 1. 03814| 1. 03998 5. 57
11 8. 689| 3941. 4 8. 698 3945. 4| 65. 00| 1. 04229| 1. 04413 6. 13
12 8. 724, 3957. 2 8. 733| 3961. 2 65. 26|| 1. 04646| 1. 04831 6. 68
13 8. 759| 3973. 1 || 8. 768] 3977. 1 || 65. 52| 1. 05066|| 1. 05252 7. 24
14 8. 795 3989. 2. 8. 803|| 3993. 2' 65. 79| 1. 05490|| 1. 0.5677 7. 79
15 8. 830 4005. 3| 8. 839 4009. 3| 66. 05| 1. 0.5916| 1. 06104 8. 34
16 8. 866|| 4021. 6| 8. 875|| 4025. 5, 66. 32 1. 06346|| 1. 06534 8. 89
17 8. 902| 4038. 0|| 8. 911 || 4041. 9, 66. 59| 1. 06779| 1. 06968 9. 45
18 8. 939 4054. 5| 8. 947. 4058. 4| 66. 87| 1. 07215 1. 07404 10. 00
19 8. 975 4071. 1 || 8. 984. 4075. 0 67. 14| 1. 0.7654| 1. 0.7844 10. 55
20 9. O12| 4087. 8 9. 021| 4091. 8| 67. 42|| 1. 08096 1. 08287| 1.1. 10
21 9. 049 4104. 7| 9. 0.58|| 4108. 6] 67. 69| 1. 0854.1 | 1. C8733| 11. 65
22 9. 087. 4121. 7| 9. 095| 4125. 6. 6.7. 97.| 1. 08990) 1. 09183| 12. 20
23 9. 125 4138. 8] 9. 133 4142. 8, 68. 26|| 1. 09442|| 1. 09636|| 12. 74
24 9. 163| 4156. 0| 9. 171 || 41.60, 0, 68. 54|| 1. 09897| 1. 10092] 13, 29
25 9. 201| 4173. 4. 9. 209 4177. 3| 68. 83| 1. 10356| 1. 10551 | 13. 84
26 9. 239 4190. 9] 9. 248, 4.194. 8, 69. 11 | 1. 10818 1. 11014, 14. 39
27 9. 278 4208. 5 9. 287| 4212. 4| 69. 41 | 1. 11283| 1. 11480, 14. 93
28 9. 317| 4226. 2 9. 326|| 4230. 2 69. 70 l. 11751 | 1. 11949. 15. 48
29 9. 357 4244. 1 9. 365. 4248. 0. 69. 99| 1. 12223| 1. 12422, 16. 02
30 9. 396 4262. 1 9. 405| 4266. 0 70. 29| 1. 12698 1. 12898 16. 57
31 9. 436 4280. 2 9. 445. 4284. 2 70. 59| 1. 13177| 1. 13378, 17. 11
32 9. 477| 4298. 5 9. 485 4202. 4| 70. 89| 1. 13660| 1. 13861| 17. 65
33 9. 517 4316. 8 9. 526 4320. 8| 71. 19| 1. 14145| 1. 14347| 18. 10
34 9. 558 4335. 4. 9. 566. 4339. 3| 71. 50: 1. 14634. 1. 14837| 18. 73
35 9. 599 4354. 0 9. 608 4358. 0 71. 81 | 1. 15128 1. 15331 | 19. 28
1 Wiss. Kaiserlichen Normal-Aichungs-Kommission 2, 153 (1900).
* Tech. Pap. BS T115 (1918).
*After the computations were completed, the tabulations were made by rounding off the results to the
last figure given.
I’olarimetry, Saccharimetry, and the Sugars
645
TABLE 117.-Weight per United States gallon and weight per cubic foot of sugar
(sucrose) solutions at 20° C–Continued
Sucrose
by
weight
(Brix)
Weight S fic | S
V of e per pecific | Specific
W * per Yº !. o cubic grayity, grayity, Baumé
gallon in alr gallon ln Vacu foot 20°/4° C120°/20°C
in air
lb 9 lb g lb
9. 640 4372. 8| 9. 649 4376. 7| 72. 12| 1. 15624 1. 15828, 19. 81
9. 682| 4391. 8| 9. 691 || 4395. 7| 72.43| 1. 16.124. 1. 16329| 20. 35
9. 724. 4410. 8] 9. 733| 4414. 7| 72. 74| 1. 16627| 1. 16833| 20. 89
9. 766|| 4430. O. 9. 775|| 4.433. 9| 73. 06| 1. 17134|| 1. 17341| 21.43
9. 809| 4449. 3| 9. 818. 4453. 3| 73. 38 1. 17645| 1. 17853| 21.97
9. 852 4468. 8] 9. 861| 4472. 7| 73. 70| 1. 18159| 1. 18368| 22. 50
9. 895. 4488. 4. 9. 904 4492. 3| 74.02 1. 18677| 1. 18887. 23. 04
9. 939| 4508. 2 9. 947| 4512. 1 || 74. 35 | 1. 19199| 1. 19410| 23. 57
9. 983| 4528. 1 || 9. 991) 4532. 0 74. 68 1. 19725] 1. 19936 24. 10
10. 027| 4548. 1 || 10. 035| 4552. 0|| 75. 01 | 1. 20254. 1. 20467| 24, 63
10. 071. 4568. 3| 10. 080. 4572. 2 75. 34 1. 20787] 1. 21001 || 25, 17
10. 116| 4588. 6| 10. 125| 4592. 5 75. 67| 1. 21324| 1. 21538 25. 70
10. 161| 4609. I | 10. 170| 4613. 0 76. 01 | 1. 21864. 1. 22080| 26. 23
10. 207| 4629. W. 10. 215| 4633. 6|| 76. 35| 1. 22409| 1. 22625, 26. 75
10. 252| 4.650. 4| 10. 261| 4654. 3| 76. 69| 1. 22957| 1. 23174| 27. 28
10. 299| 4671. 3| 10. 307| 4675. 2 77. 04: 1. 23508 1. 23727| 27. 81
10. 345. 4692. 4 10. 353. 4696. 3| 77. 39| 1. 24064| 1. 24284. 28. 33
10. 392 4.713. 5| 10. 400| 4717. 4| 77. 73| 1. 24623 1. 24844, 28. 86
10. 439| 4734, 9; 10, 447| 4738, 7| 78. 09| 1. 25.187| 1. 25408. 29. 38
10. 486|| 4756. 3| 10. 494| 4760. 2 78. 44| 1. 25754|| 1. 25976. 29. 90
10. 534, 4777. 9| 10. 542 478.1. 8 78. 80) 1. 26324| 1. 26548, 30. 42
10. 581| 4799. 7 10. 590 4803. 5| 79. 15| 1. 26899| 1. 27123| 30. 94
10. 630| 4821, 6|| 10. 638|| 4825, 4| 79, 52| 1. 274.77| 1. 27703|| 31.46
10. 678| 4843. 6 10. 687| 4847. 5. 79. 88 1. 28060| 1. 28286|| 31. 97
10. 727| 4865. 8, 10. 736|| 4869, 7 80. 25| 1. 28646|| 1. 28873| 32.49
10. 7.77|| 4888. I | 10. 785| 4892. 0 80. 61 | 1. 29235| 1. 29464| 33.00
10. 826|| 4910. 6|| 10. 835| 4914. 5 80. 98| 1. 298.29| 1. 30059) 33. 51
10. 876 4933. 2. 10. 884. 4937. 1| 81. 36|| 1. 30427| 1. 30657| 34. 02
10. 926|| 4956. O| 10. 935| 4959. 9; 81. 73| 1. 31028 1. 31260. 34. 53
10. 977| 4978. 9| 10. 985| 4982. 8, 82. 11 | 1. 31633 1. 31866 35. 04
11. 027 5002. 0 1 1. O36|| 5005. 8| 82.49| 1. 32242|. 1. 32476 35. 55
11. 079 5025. 2, 11. 087| 5029. 0 82. 87| 1. 32855| 1. 33090|| 36. 05
11. 130| 5048. 5|| 1 1. 139| 5052. 4| 83. 26 1. 33472| 1. 33708. 36. 55
11. 182 5072. 0 1 1. 190 5075. 9| 83. 65] 1. 340.93| 1. 34330, 37. 06
11. 234 5095. 7 11. 242 5099. 5| 84. 04| 1.347.17 1. 34956) 37, 56
11. 286|| 5119. 5| 1 1. 295 5123. 3| 84. 43| 1. 35346|| 1. 35585| 38. 06
11. 339|| 5143. 4 11. 348, 5.147. 2 84. 82| 1. 35978 1. 36218, 38. 55
11. 392 5167. 5 11. 401 || 5171. 3| 85. 22. 1. 36614| 1.36856| 39. 05
11. 446 5191. 7] 1 1. 454|| 5195, 5| 85. 62| 1.37254| 1.37496. 39. 54
11. 499| 5216. 1 || 1 1. 508 5.219. 9| 86. 02| I. 37897| 1. 38141 40. 03
11. 554 5.240. 6 11. 562 5244. 4 86. 43| 1. 385.45| 1. 387.90 40. 53
11. 608: 5265. 2. 11. 616 5269. 0| 86. 83| 1. 39.196 1. 39442. 41. 01
11. 663| 5290 0 1 1. 671 5293. 8 87. 24. 1. 39850| 1. 40098. 41. 50
11. 717. 5315. 0 1 1. 726. 5318. 8 87. 65 1. 40509 1. 40758, 41. 99
11. 773| 5340, 0 1 1. 781| 5343. 8| 88. 07| 1.41 172| 1.41421| 42.47
646
%rcular of the National Bureau of Standards
TABLE 117.-Weight per United States gallon and weight per cubic foot of sugar
(sucrose) solutions at 20° C–Continued
sº Weight per Weight per wº Specific | Specific B
roi tº ge s cubic gravity, gravity, Baume
s tº gallon in air gallon in vacuo foot | 20°/4° C.20°/20°C
III 3, II"
lb g lb g lb
81 | 1.1. 828, 5365. 2 11. 837| 5369. 0| 88.48| 1. 41837| I. 42088| 42.95
82 | 11. 884. 5390. 6 11. 893. 5394. 4| 88. 90) 1. 42507| 1. 42759| 43. 43
83 || 11. 940. 5416. 1 II. 949 5419. 9 89. 32 1. 43181| 1. 43434 43. 91
84 || 11. 997 5441. 7| 12. 005| 5445. 5 89. 74| 1. 43858| 1. 441 12| 44. 38
85 | 12. 0.54|| 5467. 5 12. 062| 5471. 3| 90. 17| 1. 44539| 1.44794| 44, 86
86 | 12. II 1 5493. 4 12. 119| 5497. 2 90. 60| 1. 45223| 1. 45480| 45. 33
87 i 12. 168| 5519. 5| 12. 177 5523. 3| 91. 03| 1. 45911| 1. 46170 45. 80
88 | 12. 226 5545. 6 12. 234 5549. 4| 91.46 1. 46603| 1. 46862. 46. 27
89 12. 284. 5572. 0 12. 292 5575. 7| 91. 89| 1. 47299| 1. 47559 46. 73
90 | 12. 342| 5598. 4| 12. 351 5602. 2 92. 33 1. 47998 1. 48259| 47. 20
91 | 12. 401 5625. 1 | 12. 409| 5628. 8| 92. 77| 1. 48700. 1. 48963| 47. 66
92 || 12. 460 565.1. 8 12. 468 5655. 5 93. 21 | 1. 4.9406 1. 49671| 48. 12
93 12, 519 5678. 6 12. 527| 5682. 4 93. 65. 1. 501.16|| 1. 50381| 48. 58
94 | 12. 579| 5705. 7| 12. 587 5709. 4| 94. 10 1. 50829| 1. 51096, 49. 03
95 | 12, 639| 5732, 8 12, 647| 5736. 5 94. 54| 1. 51546 1. 51814| 49. 49
Polarimetry, Saccharimetry, and the Sugars
647
TABLE 118.—Weight per United States gallon of sugar (sucrose) solutions at different
temperatures
[The values obtained by extrapolation are given in italics]
Sucrose Weight per gallon in air at tº C
by
weight
(Brix) | t- 100 C t = 15° C t = 20° C. t = 25° C t = 30° C.
lb g lb 9. lb 9. lb ſ] lb g
0 | 8. 334|| 3, 780 8.329 3, 778, 8.322 3, 775 8. 312| 3, 770 8.301 3, 765
5 | 8. 500 3,856 8.494 3, 853 8.485| 3, 849 8.475 3, 844 8. 463 3, 839
10 || 8.672, 3,933 8. 664 3, 930 8. 655, 3,926 8.644, 3,921| 8.631|| 3,915
15 8. 849 4, 0.14|8. 841| 4, 010| 8. 830| 4,005 8.818, 4,000 8. 805| 3,994
20 9.034| 4,098 9, 023| 4,093 9. 012| 4,088 8.999| 4,082 8.985| 4,075
25 || 9, 225| 4, 184|9. 213| 4, 179| 9, 201| 4, 173| 9. 187| 4, 167 9. 171| 4, 160
30 | 9.423| 4, 274. 9. 410| 4, 268|9. 396 4, 262 9. 381| 4, 255 9. 365| 4, 248
35 | 9.628 4, 367| 9. 614 4, 361| 9. 599| 4, 354. 9. 583| 4, 347 9 566| 4, 339
40 || 9, 840 4,464 9, 825 4, 457 9.809 4,449. 9. 792] 4,442 9.774|4, 433
45 |10. 060 4, 563|10. 044| 4, 556|10. 027| 4, 548|10. 009| 4, 540 9. 990 4, 531
50 10 288 4,667|10. 271 4, 65910. 252 4, 65010. 234|4,642|10. 214|4,633
55 |10. 523| 4, 773|10. 505| 4, 765|10. 486| 4, 75610. 466|| 4, 747|10. 446 4, 738
60 |10. 767| 4, 884|10. 747| 4, 875|10. 727| 4, 866|10. 707| 4, 856|10. 685| 4, 847
65 |11. 018|4, 998|10. 997.| 4, 988|10. 977| 4, 979|10. 955| 4, 969||10. 933| 4, 959
70 |11. 277| 5, 115||11. 256 5, 105||11. 234, 5,096]11. 212 5,086||11. 189| 5,075
75 |11. 544| 5, 236||11. 522 5, 226||11. 499 5, 216|11. 477| 5, 206||11. 453| 5, 195
80 |11. 818 5, 361||11. 796|| 5, 351|11. 773| 5, 340|11. 749| 5, 329|11. 725] 5, 319
85 |12. 101| 5, 489|12. 078| 5, 478|12. 054, 5,467|12. 030) 5, 457|12. 005 5, 445
90 |12. 391 || 5, 62012. 367 5, 610|12. 342 5, 598|12. 318| 5, 587|12. 293 5, 576
95 |12. 688 5, 755|12. 664 5, 744|12. 639| 5, 733|12. 613| 5, 721|12. 587| 5, 709
648
Circular of the National Bureau of Standards
TABLE 119.- Volume of sucrose solutions at different temperatures 1
[Volume at 20°C = 1.0000]
Percentage of sucrose by weight
Tem- -
pera- 0 5 10 15 20 25 30 35
ture
“f”, volumE FACTOR (volumE t = volumE 20°C Xf)
oC -
0 0. 9984 0. 9976|| 0. 9969; 0.9964] O. 9958|| 0. 99.54|| O. 9949| 0. 9945
5 . 99.82 . 99.78 . 99.74 . 9970 . 9966. , 9963| . 9960 . 99.57
10 . 9985 . 9983 . 9981 . 99.78 . 9976 . 99.74| . 99.72| . 9970
15 . 999.1 . 9990 . 9989 . 9988 . 99.87| . 9986| . 9985| . 99.84
20 1. 0000| 1. 0000| 1. 0000| 1, 0000| 1. 0000| 1. 0000. 1, 0000| 1. 0000
25 1. 0012| 1. 0012| 1. 0013| 1. 001.4| 1. 001.4| 1. 0015 1. 0016| 1. 001.7
30 1. 0026|| 1. 0026|| 1. 0027| 1. 0029| 1. 0030| 1. 0.032 1. 0033| 1. 0035
35 1. 0.042| 1. 0043| 1. 0.044|| 1. 0046|| 1. 0.048| 1. 0.050. 1. 0.052| 1. 0.054
40 1. 0060| 1. 0061| 1. 0.063| 1. 0065. 1. 0068| 1. 0070. 1. 0072| 1. 0074
45 1. 0080| 1. 0081 | 1. 0084. 1. 0.086 1. 0089| 1. 0.091 | 1. 009.4| 1. 0096
50 1. 0102| 1. 0104| 1. 0.106| 1. 0109| 1. 0112| 1. 0115| 1. 01 17| 1. 0119
55 1. 0126; 1. 0128| 1. 0131 | 1. 0134| 1. 0137| 1. 0.139| 1. 0141| 1. 0.143
60 1. 0152| 1. O155| 1. 0158| 1. 0161| 1. 0163| 1. 0165| 1. 0167| 1. 0168
65 1. 0179| 1. 0184| 1. 0186 1. 0189| 1. 0191 | 1. 0194| 1. 0196|| 1. 0196
70 1. 0209| 1. 0213| 1. 0215| 1. 0218 1. 0218| 1. 0221 | 1. 0223| 1. 0224
75 1. 0241 1. 0243 1. 0244| 1. 0247| 1. 0248| 1. 0250) 1. 0251 1. 0.252
80 1. 0274| 1. 0273| 1. 0275|| 1, 0.277| 1. 0279| 1. 0280| 1. 0281| 1. 0281
85 1. 0308|| 1. 0307| 1. 0309|| 1. 0309|| 1. 0312|| 1. 0312| 1. 0312|| 1. 0312
90 1. 0342 1. 0342 1. 0344| 1. 0344. 1. 0347| 1. 0346 1. 0345 1. 0344
95 1. 0376|| 1. 0379| 1. 0380| 1. 0380| 1. 0382| 1. 0381 | 1. 0379| 1. (*377
100 1. 0411| 1. 0417| 1. 0418 1. 0417| 1. 0417| 1. 0415 1. 0413| 1. 0412
1 Factors for concentrations from 0 to 70 percent at temperatures from 0° to 60°C computed from Plato's
density tables (Kaiserlichen Normal-Eichungs-Kommission, Wiss. Abh. 2 (1900)); remaining factors compu-
ted from Th. Gerlach, Z. Ver. deut. Zucker-Ind. 13, 320 (1863).
Polarimetry, Saccharimetry, and the Sugars
649
TABLE 119.-Volume of sucrose solutions at diflerent temperatures 1—Continued
[Volume at 20°C = 1.0000]
Percentage of sucrose by weight
Tem-
pera- 40 45 50 55 60 65 70 75
ture
“f”, volumE FACTOR (volumE t = volumE 20°C Xf)
oC
() 0. 994 || 0. 9937| 0. 99.34 0. 9931|| 0. 99.29| 0. 9928|| 0. 9926|| 0. 9927
5 . 99.54 . 9952 . 99.49 . 9948 . 9946| . 9945| . 9944 . 9945
10 . 9969 . 9967 . 9966 . 9964 . 9963| . 9963| . 9962| . 9964
15 . 99.84 . 9983 . 99.82 . 99.82 . 9981| . 9981| . 9981| . 99.82
20 1. 0000|| 1. 0000|| 1. 0000| 1. 0000| 1. 0000| 1. 0000| 1. 0000| 1. 0000
25 1. 0018; 1. 0018 1. 0018| 1. 0019| 1. 0019| 1. 0019| 1. 0020|| 1. 0019
30 1. 0036 1. 0037 1, 0038|| 1. 0039| 1. 0039| 1. 0039| 1. 0040 1. 0038
35 1. 0056|| 1. 0.057| 1. 00:58| 1. 0.059| 1. 0060|| 1. 0060|| 1. 0.061 | 1. 00:58
40 1. 0076|| 1. 0078 1. 0079| 1. 0080| 1. 0081| 1. 0081 | 1. 0082| 1, 0078
45 1. 0098. 1, 0099| 1. 0100| 1. 0102| 1. 0102| 1. 0103|| 1. 0103| 1. 0099
50 1. 0120 | 1. 0122| 1. 0123| 1. 0124| 1. 0125 1. 0125 1. 0125 1. 0121
55 1. O144| 1. 0145| 1. 0147| 1. 0.148 1. 01:48 1. 0.148 1. 0148| 1.0143
60 1. 0169| 1. 0170 1. O171| 1. 0172| 1. 0172| 1. 0172| 1. 0171 | 1. 0166
65 1. 0200. 1, 0202| 1. 0199| 1. 0199| 1. 0198 1. 0194 1. 0189| 1. 0190
70 1. 0227| 1. 0229| 1. 0225| 1. 0225| |. 0223 1. 0219| 1. 0215 1. 0214
75 1. 0.254. 1. 0257| 1. 0252| 1. 0251 | 1. 0250) 1. 0244| 1. 0241| 1. 0238
80 1. 0283 1. 0286|| 1. 0280| 1. 0.278 1. 0277| 1. 0270| 1. 0.268 1. 0.263
85 1. 0312|| 1. 0317| 1. 0310|| 1. 0306| 1. 0305| 1. 0297| 1. 0294| 1. 0289
90 1. 0343| 1. 0347| 1. 0340| 1. 0334|| 1. 0334|| 1. 0326|| 1. 03:22| 1. 0316
95 1. 0375|| 1. 0378 1. 0371 | 1. 0364| 1. 0363| 1. 0354 1. 0351 | 1. 0343
100 1. 0409| 1. 0409|| 1 0403| 1. 0395| 1. 0393 1. 0383| 1. 0380) 1. 0370
1 Factors for concentrations from 0 to 70 percent at temperatures from 0° to 60°C computed from Plato's
density tables (Kaiserlichen Normal-Eichungs-Kommission, Wiss. Abh. 2 (1900)); remaining factors compu-
ted from Th. Gerlach, Z. Ver. deut. Zucker-Ind. 13, 320 (1863).
650 Circular of the National Bureau of Standards
TABLE 120.-Density of levulose solutions and mean density and expansion coefficients
between 20° and 25°C
[All weights corrected to vacuum]
Levu-
lº D% Dº — AD/At | Av/At
weight
% × 10-6 × 10-6
0 0. 99.823 0. 99708 231 231
1 1. 00214 1. 000.95 238 237
2 1. 00607 1, 00484 245 243
3 1. 01003 1. 00877 252 249
4 1. 01402 1. 01272 259 255
5 1. 01803 1. 01670 266 261
6 1. O2207 1. 02071 273 267
7 1. 02614 1. 02475 280 273
8 1. 03024 1. 0288.1 287 278
9 1. 03437 1. 03290 294 284
10 1. 03853 1. 03702 301 290
11 1. 04271 1. 04.118 308 295
12 1. 04692 1. 04535 315 300
13 1. 05] 16 1. 0.4955 323 307
14 1. 05.543 1. 05378 330 313
15 1. 05972 1. 05804 337 3.18
16 1. 06405 1. 06233 345 324
17 1. 06840 1. 06664 352 329
| 8 1. 07278 1. 07098 360 336
19 I. 07719 1. 07535 367 341
20 1. 0.8162 1. 07975 375 347
× 10-5 × 10-5
21 1. 08606 1. 0.842 38 35
22 1. 09055 1. 0886 38 35
23 1. 09507 1. 0931 39 36
24 1. 0.9962 1. 0976 40 36
25 1. 10420 1. 1022 41 37
26 1. J 088 1. 10675 41 37
27 1. 11345 1. 11135 42 38
28 1. 1181 1. 1160 43. 38
29 1. 1229 1. 1207 43 39
30 1. 1276 1. 1254 44 39
31 1. 1324. 1. 13015 45 40
32 1. 1372 1. 1349 46 40
33 1. 14205 1. 1397 46 40
34 1. 1469 1. 1446 47 41
35 1. 1518.5 1. 1495 48 41
36 1. 1568 1. 1544 48 42
37 1. 1618 1. 1593 49 42
38 1. 1668 1. 1643 50 43
39 1. 1718 1. 1693 50 43
40 1. 1769 1. 17435 51 43
Polarimetry, Saccharimetry, and the Sugars
651
º – AD/At | Av/At
D29 D25 -
by 4. 4
weight X 10-5 × 10-5
41 1. 1820 1. 1794 52 44
42 1. 1872 1. 1845 53 44
43 1. 1923 1. 1897 53 45
44 1. 1975 1. 19485 54 45
45 1. 2028 1. 20005 55 45
46 1. 20805 1. 2053 55 46
47 1. 2134 1. 2106 56 46
48 1. 21.87 1. 21.59 57 46
49 1. 2241 1. 2212 57 47
50 1. 2295 1. 2266 58 47
51 1. 2349 1. 2320 59 47
52 1. 2404 1. 2374 59 48
53 1. 2459 1. 2429 60 48
54 1. 25.14 1. 2484 60 48
55 1. 2570 1. 2539 61 49
56 1. 2626 1. 2595 62 49
57 1. 2682 1. 2651 62 49
58 1. 2739 1. 2707 63 50
59 1. 2796 1. 2764 64 50
60 1. 2853 1. 2821 64 50
61 1. 2911 1. 2878 65 50
62 1. 2969 1. 2936 66 51
63 1. 3027 1. 2994 66 51
64 1. 3086 1. 3052 67 51
65 1. 31.45 1. 3111 67 51
66 1. 3204 1. 31.70 68 51
67 1. 3263 1. 3229 69 52
68 1. 3323 1. 3289 69 52
69 1. 3384 1. 3349 70 52
70 1. 3444 1. 34.09 70 52
71 1. 3505 1. 3470 71 53
TABLE 120.-Density of levulose solutions and mean density and expansion coefficients
between 20° and 25° C–Continued

652
Circular of the National Bureau of Standards
TABLE, 121.- Density of dertrose solutions .
{D}=0.998.40+0.003788p–H 0.00001412p2]
Concentra- Concentra- Concentra-
tion by I)30 tion by I):0 tion by D30
weight in 4 weight in * 4 weight in 12" 4
Va,CUlO V8,CUlO V8,OUIO
Percent Percent - Percent
4 1. 01378 13 1. 05003 22 1. 08857
5 1. 0.1769 14 1. 0.542() 23 1. 09.299
6 1. 02164 15 1. 05840 24 1. 09744
7 1. 02:561 16 1. 06262 25 1. 101.92
8 1. 02961 17 1. 06688 26 1. 10643
9 1, 03364 18 1. 071.16 27 1. 11097
10 1. 03769 19 1. 07547 28 1. 11553
11 1. 041 78 20 1. 07981 29 1. 1 2013
12 1. 04589 21 1. 0.8417 30 1. 12475
| R. F. Jackson, Bul. BS 13, 642 (1916) S293.
TABLE 122.- Refractive index of sucrose solutions at 20° C
Sucrose Rºº. Sucrose Refrac- Sucrose Refrac- Sucrose Refrac-
by tiye by tive by t] Ve by tive
weight intº weight index, weight index, | weight index,
HD 77% 717; 7t;
|
% % % | 9%
(). 0 | 1. 33299 3. 0 | 1. 33733 6. 0 | 1. 34.176 9. 0 | 1. 34.629
. 1 | 1. 33.313 . 1 | 1. 33748 . 1 | 1. 34.191 . 1 | 1. 34644
. 2 | 1. 33328 2 | 1. 33762 . 2 | 1. 34.206 . 2 | 1. 34.660
. 3 | 1. 33342 . 3 | 1. 337.77 . 3 | 1. 34221 . 3 | 1, 34675
. 4 | 1. 33.357 . 4 || 1. 33792 . 4 | 1. 34236 . 4 | 1. 34.691
. 5 | 1. 33371 . 5 || 1. 33807 . 5 | 1.34251 . 5 I. 34.706
. 6 1. 33385 . 6 | 1. 33821 6 | 1.34266 . 6 1, 34721
. 7 | 1. 33400 . 7 | 1. 33836 7 | 1.34281 . 7 | 1. 34537
. 8 || 1. 33414 . 8 || 1. 33851 8 || 1.34296 . 8 || 1. 34752
, 9 | 1. 33429 . 9 1, 3.3865 . 9 1. 34311 . 9 | 1. 34768
1. 0 | 1. 33443 4. 0 | 1. 33880 7. 0 | 1. 34.326 10. 0 | 1. 34.783
. 1 | 1. 33457 . 1 | 1. 33895 . 1 | 1. 34341 . 1 | 1. 34.798
. 2 | 1. 334.72 . 2 | 1. 33909 . 2 | 1. 34356 . 2 | 1. 34814
. 3 | 1. 33487 . 3 | 1. 33924 . 3 | 1. 34371 . 3 | 1. 34829
. 4 | 1. 33501 . 4 || 1: 33939 . 4 | 1.34386 . 4 | 1. 34845
. 5 | 1. 33515 . 5 | 1. 33953 . 5 | 1. 34401 . 5 1, 34.860
. 6 | 1. 33530 . 6 || 1: 33968 . 6 | 1.34417 . 6 | 1. 34875
. 7 | 1. 33545 . 7 | 1. 33983 . 7 | 1. 34.432 . 7 | 1. 34891
. 8 | 1. 33559 . 8 || 1. 33998 . 8 | 1. 34447 . 8 | 1. 34906
. 9 || 1. 33573 . 9 || 1. 34012 . 9 | 1. 34.462 . 9 | 1. 34922
2. 0 | 1. 33588 5. 0 | 1. 34027 8. 0 | 1. 34.477 11. 0 | 1. 34937
. 1 | 1. 33603 . 1 || 1 34042 . 1 | 1. 34492 . 1 | 1. 34953
. 2 | 1. 33617 . 2 | 1. 34.057 . 2 | 1. 34507 . 2 | 1. 34968
. 3 | 1. 33631 . 3 | 1. 34.072 . 3 | 1. 34523 . 3 | 1. 34984
. 4 | 1. 33646 . 4 | 1. 34087 . 4 | 1. 34538 . 4 || 1. 34999
. 5 | 1. 33661 . 5 | 1. 34101 . 5 | 1. 34553 . 5 | 1. 35015
. 6 | 1. 33675 . 6 | 1. 341.16 . 6 | 1. 34568 . 6 | 1. 35031
. 7 | 1. 33689 . 7 | 1. 34.131 . 7 || 1 34583 . 7 | 1. 35046
. 8 | 1. 33704 . 8 || 1. 34.146 . 8 | 1. 34599 . 8 1. 35062
. 9 | 1. 33719 . 9 | 1. 34161 . 9 | 1. 34614 . 9 | 1. 35077
1 The values of refractive indices for whole percents of sucrose are those of the “International Scale of
Refractive Indices of Sucrose at 20°C, 1936”, adopted by the International Commission for Uniform Meth-
ods of Sugar Analysis, Ninth Session, London, 1936. The remaining values were obtained by interpolation.
Int. Sugar J. 39, 22s (1937).
Polarimetry, Saccharimetry, and the Sugars
653
TABLE 122.—Refractive inder of sucrose solutions at 20° C–Continued
Sucrose Rºtº- Sucrose R; f* || Sucrose R * || Sucrose Rºº.
by iº, by iº, by iº by iº,
weight m}} y weight n; s weight m; y weight n; y
% % % %
12. 0 | 1, 35093 17. 0 | 1. 35890 22. 0 | 1. 36719 27. 0 | 1. 37.58
. 1 | 1. 35.109 . 1 | 1. 35906 . 1 | 1. 36736 . 1 | 1. 3760
. 2 | 1. 35124 2 | 1. 35923 . 2 | 1. 36753 . 2 | 1. 3761
. 3 | 1. 35140 . 3 | 1. 35939 . 3 | 1. 36770 . 3 | 1. 3763
. 4 | 1. 351.56 . 4 | 1. 35955 . 4 | 1. 36787 . 4 || 1. 3765
. 5 | 1. 35171 . 5 | 1. 35971 . 5 | 1. 36803 . 5 | 1. 3767
. 6 | 1. 351.87 . 6 | 1. 35988 . 6 | 1. 36820 . 6 I. 3768
. 7 | 1. 35203 . 7 | 1. 36004 . 7 | 1. 36837 . 7 | 1. 3770
. 8 || 1. 35219 . 8 1. 36020 . 8 | 1. 36854 . 8 || 1. 3772
. 9 || 1. 35234 . 9 || 1. 36037 . 9 | 1. 36871 . 9 | 1. 3773
13. 0 | 1. 35250 18. 0 | 1. 36053 23. 0 | 1. 36888 28. 0 | 1. 3775
. 1 || 1, 35.266 . 1 | 1. 36069 . 1 | 1. 36905 . 1 | 1. 37.77
. 2 | 1. 35282 . 2 | 1. 36086 . 2 | 1. 36922 . 2 | 1. 3779
. 3 | 1. 35.297 . 3 | 1. 36103 . 3 | 1, 36939 . 3 | 1. 3780
. 4 || 1, 35313 . 4 | 1. 36119 . 4 || 1. 36956 . 4 || 1, 3782
. 5 | 1, 35329 . 5 | 1. 36135 . 5 | 1. 36973 . 5 | 1. 3784
. 6 1, 35345 . 6 | 1. 36152 . 6 | 1. 36991 . 6 | 1. 3786
. 7 | 1. 35.361 . 7 | 1. 36.169 . 7 || 1, 37008 . 7 | 1, 3788
. 8 || 1, 35376 . 8 || 1. 36.185 . 8 || 1, 37025 . 8 || 1, 3789
, 9 || 1, 35392 , 9 1, 36201 , 9 || 1, 37042 , 9 1, 3791
14. 0 | 1. 35408 19. 0 | 1, 36.218 24. 0 | 1. 37059 29, 0 | 1, 3793
. 1 | 1. 354.24 . 1 | 1. 36235 . 1 || 1, 3708 . 1 | 1. 3795
. 2 | 1. 35440 . 2 | 1. 36251 . 2 | 1, 3709 . 2 | 1. 3797
. 3 | 1. 35456 , 3 | 1. 36268 . 3 | 1, 37.11 . 3 | 1, 3798
. 4 | 1. 35472 . 4 | 1. 36284 . 4 | 1. 3713 . 4 || 1. 3800
. 5 | 1. 35487 . 5 | 1. 36301 . 5 1, 3715 , 5 | 1. 3802
. 6 | 1. 35503 . 6 | 1. 36318 . 6 | 1. 3716 . 6 | 1. 3804
. 7 | 1. 35519 . 7 | 1. 36334 . 7 | 1. 3718 . 7 | 1. 3806
. 8 | 1. 35.535 . 8 | 1. 36351 . 8 | 1. 3720 . 8 | 1. 3807
. 9 | 1. 3555.1 . 9 || 1. 36367 . 9 || 1. 3721 . 9 | 1. 3809
15. 0 | 1. 35567 20. 0 | 1. 36384 25. 0 | 1. 3723 30. 0 | 1. 381 1
. 1 | 1. 35.583 . 1 | 1. 36401 . 1 | 1. 3725 . 1 | 1. 3813
. 2 | 1. 35599 . 2 | 1. 36417 . 2 | 1. 3726 . 2 | 1. 3815
. 3 | 1. 35615 . 3 | 1. 36434 . 3 | 1. 3728 . 3 | 1. 3816
. 4 | 1. 35631 . 4 | 1. 36451 . 4 | 1. 3730 . 4 || 1. 3818
. 5 | 1. 35647 . 5 | 1. 36467 . 5 | 1. 3731 . 5 | 1. 3820
. 6 | 1. 35664 . 6 | 1. 36484 . 6 | 1. 3733 . 6 | 1. 3822
. 7 | 1. 35.680 . 7 | 1. 36501 . 7 | 1. 3735 . 7 | 1. 3824
. 8 || 1. 35696 . 8 || 1, 36518 . 8 || 1. 3737 . 8 || 1. 38.25
, 9 1, 35.712 , 9 | 1. 36534 , 9 | 1. 3738 . 9 | 1. 3827
16. 0 | 1. 35728 21. 0 | 1. 36551 26. 0 | 1. 3740 31. 0 | 1. 3829
. 1 | 1. 35744 . 1 | 1. 36568 . 1 | 1. 3742 . 1 | 1. 38.31
. 2 | 1. 35760 . 2 | 1. 36585 . 2 | 1. 3744 . 2 | 1. 3833
. 3 | 1. 35777 . 3 | 1. 36601 . 3 | 1. 3745 . 3 | 1. 3834
. 4 | 1. 35793 . 4 j 1, 366.18 . 4 | 1. 3747 . 4 | 1. 3836
. 5 | 1. 35809 . 5 | 1. 36635 . 5 | 1. 3749 . 5 | 1. 3838
. 6 | 1. 35825 . 6 | 1. 36652 . 6 | 1. 37.51 . 6 | 1. 3840
. 7 | 1. 35841 . 7 | 1. 36669 . 7 | 1. 3753 . 7 | 1. 3842
. 8 || 1. 35858 . 8 | 1. 36685 . 8 | 1. 3754 . 8 | 1. 3843
. 9 || 1. 35874 . 9 | 1. 36702 . 9 | 1. 3756 . 9 || 1. 3845
323414°–42—43
654
Circular of the National Bureau of Standards
TABLE 122.-Refractive indea: of sucrose solutions at 20° C–Continued
Sucrose Rºº- Sucrose Rºº. Sucrose Refrac- Sucrose Refrac-
by - º, by iº, by iº by º
weight º y weight n; y weight n;" weight | n;"
% % % %
32, 9 || 1. 3847 37. 0 | 1. 3939 42. 0 | 1. 4036 47. 0 | 1. 41.37
. 1 | 1. 3849 . 1 | 1. 3941 . 1 | 1. 4038 . 1 | 1. 4139
. 2 | 1. 3851 . 2 | 1. 3943 . 2 | 1. 4040 . 2 | 1. 4141
. 3 | 1. 3852 . 3 | 1. 3945 . 3 | 1.4042 . 3 | 1. 4143
4 | 1. 3854 . 4 || 1, 3947 . 4 | 1. 4044 . 4 | 1. 4145
. 5 | 1. 3856 . 5 | 1. 3949 . 5 | 1. 4046 . 5 | 1. 4147
6 | 1. 3858 . 6 | 1. 3950 . 6 | 1. 4048 . 6 | 1.4150
7 | 1. 3860 . 7 | 1. 3952 . 7 | 1. 4050 . 7 | 1. 4152
. 8 || 1. 3861 . 8 || 1. 3954 . 8 || 1. 4052 . 8 | 1. 41.54
, 9 | 1. 3863 . 9 | 1. 3956 . 9 || 1, 4054 . 9 | 1. 4156
33. 0 | 1. 3865 38. 0 | 1. 3958 43. 0 | 1. 4056 48. 0 | 1. 41.58
1 | 1. 3867 . 1 | 1. 3960 . 1 || 1: 4058 . 1 | 1. 4160
. 2 | 1. 3869 . 2 | 1. 3962 . 2 | 1, 4060 . 2 | 1. 4.162
. 3 | 1. 3870 . 3 | 1. 3964 . 3 | 1. 4062 . 3 | 1. 4164
. 4 || 1. 3872 . 4 || 1. 3966 . 4 || 1, 4064 . 4 1. 4166
. 5 | 1. 3874 . 5 | 1. 3968 . 5 | 1. 4066 . 5 | 1. 41.69
. 6 | 1. 3876 . 6 | 1. 3970 . 6 | 1. 4068 . 6 | 1. 4171
7 | 1. 3878 . 7 | 1.3972 . 7 | 1. 4070 . 7 | 1. 4173
. 8 | 1. 3879 . 8 || 1. 3974 8 || 1. 4072 . 8 | 1. 41.75
. 9 | 1. 3881 . 9 | 1. 3976 , 9 || 1. 4074 . 9 || 1. 4.177
34. 0 | 1. 3883 39. 0 | 1. 3978 44, 0 | 1. 4076 49. 0 | 1. 4179
. 1 | 1. 3885 . 1 | 1. 3980 ... 1 1. 4078 . 1 | 1. 4181
. 2 | 1. 3887 . 2 | 1. 3982 , 2 | 1. 4080 . 2 | 1. 41.83
. 3 | 1. 3889 . 3 | 1. 3984 . 3 | 1. 4082 . 3 | 1.4.185
. 4 | 1. 3891 . 4 | 1. 3986 . 4 | 1. 4084 . 4 | 1. 41.87
. 5 | 1. 3893 . 5 | 1. 3987 5 | 1. 4086 . 5 | 1. 41.89
. 6 | 1. 3894 . 6 | 1. 3989 , 6 | 1. 4088 . 6 | 1. 4.192
. 7 | 1. 3896 . 7 | 1. 399.1 . 7 | 1. 4090 . 7 | 1. 4194
. 8 || 1. 3898 . 8 | 1. 3993 . 8 || 1. 4092 . 8 | 1. 41.96
, 9 | 1. 3900 . 9 | 1. 3995 , 9 | 1. 4094 . 9 | 1. 41.98
35. 0 | 1. 3902 40. 0 | 1. 3997 45. 0 | 1. 4096 50. 0 | 1. 4200
. 1 | 1. 3904 . 1 | 1. 3999 . 1 | 1. 4098 . 1 | 1. 4202
. 2 | 1. 3906 . 2 | 1. 4001 . 2 | 1. 4100 . 2 | 1. 4204
. 3 | 1. 3907 . 3 | 1. 4003 . 3 | 1. 4102 . 3 | 1. 4206
. 4 | 1. 3909 . 4 | 1. 4005 . 4 | 1. 4104 . 4 || 1. 4208
. 5 | 1. 3911 . 5 | 1. 4007 . 5 | 1, 4107 . 5 | 1. 4211
. 6 | 1. 39.13 . 6 | 1. 4008 . 6 | 1. 4109 . 6 | 1. 4213
. 7 | 1. 3915 . 7 | 1. 4010 . 7 | 1. 4111 . 7 | 1. 4215
. 8 || 1. 3916 . 8 | 1. 4012 . 8 1. 4113 . 8 || 1. 4217
. 9 | 1. 39.18 . 9 | 1. 4014 . 9 | 1. 4115 . 9 | 1. 42.19
36. 0 | 1. 39.20 41. 0 | 1. 4016 46. 0 | 1. 4117 51. 0 | 1. 4221
. 1 | 1. 3922 . 1 | 1. 4018 . 1 | 1. 4119 . I | 1. 4223
. 2 | 1.3924 . 2 | 1. 4020 . 2 | 1. 4121 . 2 | 1. 4225
. 3 | 1. 3926 . 3 | 1. 4022 . 3 | 1. 4123 . 3 | 1. 4227
. 4 | 1. 3928 . 4 | 1. 4024 . 4 | 1. 4125 . 4 | 1. 4229
. 5 | 1. 3929 . 5 | 1. 4026 . 5 | 1. 4127 . 5 | 1. 4231
. 6 | 1. 3931 . 6 | 1. 4028 . 6 1. 4129 . 6 | 1. 4234
. 7 | 1. 3933 . 7 | 1. 4030 . 7 | 1. 4131 . 7 | 1. 4236
. 8 | 1. 3935 . 8 || 1. 4032 . 8 | 1. 41.33 . 8 1. 4238
, 9 | 1. 3937 . 9 | 1. 4034 . 9 | 1. 4135 . 9 1. 4240
Polarimetry, Saccharimetry, and the Sugars
655
TABLE 122.--Refractive index of sucrose solutions at 20° C–Continued
Sucrose Rºº. Sucrose Rºº. Sucrose Rºº. Sucrose Rºº.
by, , , i. y iº, by iº, by, , , i.
weight m} y weight n; y weight n; y weight º
% % % %
52. 0 | 1. 4242 57. 0 | 1. 4351 62.0 | 1.4464 67.0 | 1. 4579
. 1 | 1. 4244 . 1 | 1. 4353 .1 | 1. 4466 . 1 | 1. 4581
. 2 | 1. 4246 . 2 | 1. 4355 .2 | 1. 4468 .2 | 1. 4584
. 3 | 1. 4249 . 3 | 1. 4358 .3 | 1.4471 .3 | 1.4586
. 4 | 1. 4251 . 4 | 1. 4360 .4 | 1. 4473 .4 | 1.4589
. 5 | 1. 4253 . 5 | 1. 4362 .5 | 1.4475 .5 | 1.4591
. 6 | 1. 4255 . 6 | 1. 4364 .6 | 1. 4477 .6 | 1.4593
7 | 1. 4257 .. 7 | 1. 4366 .7 | 1. 4479 .7 | 1.4596
. 8 || 1. 4260 . 8 || 1. 4369 .8 | 1. 4482 .8 | 1.4598
. 9 1. 4262 . 9 || 1. 4371 .9 | 1. 4484 .9 | 1. 4601
53. 0 | 1. 4264 58. 0 | 1. 4373 63.0 | 1. 4486 68.0 | 1. 4603
. 1 | 1. 4266 . 1 | 1. 4375 .1 | 1. 4488 .1 | 1. 4605
. 2 | 1.4268 . 2 | 1. 4378 .2 | 1. 4491 .2 | 1. 4608
. 3 | 1. 4270 . 3 | 1. 4380 .3 | 1. 4493 .3 | 1. 4610
. 4 | 1.4272 . 4 | 1. 4382 .4 | 1. 4495 .4 | 1. 46.13
. 5 | 1. 4275 . 5 | 1. 4385 .5 | 1. 4497 .5 | 1. 4615
. 6 | 1. 4277 . 6 | 1. 4387 .6 | 1. 4500 .6 | 1. 4617
. 7 | 1. 4279 . 7 | 1. 4389 .7 | 1. 4502 .7 | 1. 4620
. 8 | 1. 4281 . 8 | 1. 4391 .8 | 1. 4504 .8 | 1. 4622
. 9 | 1. 4283 . 9 | 1. 4394 .9 | 1. 4507 .9 | 1. 4625
54. 0 | 1. 4285 59. 0 | 1. 4396 64.0 | 1, 4509 69.0 1, 4627
. 1 | 1. 4287 . 1 | 1. 4398 .1 | 1.4511 .1 | 1. 4629
. 2 | 1. 4289 . 2 | 1. 4400 .2 | 1. 4514 .2 | 1. 4632
. 3 | 1. 4292 . 3 | 1. 4403 .3 | 1. 4516 .3 || 1 4634
. 4 | 1. 4294 . 4 || 1. 4405 .4 | 1. 4518 .4 | 1. 4637
. 5 | 1. 4296 . 5 | 1. 4407 .5 | 1. 4521 .5 | 1. 4639
. 6 | 1. 4298 . 6 | 1. 4409 .6 | 1. 4523 .6 | 1. 4641
. 7 | 1. 4300 . 7 | 1. 4411 .7 | 1. 4525 .7 | 1.4644
. 8 || 1. 4303 . 8 | 1. 4414 .8 | 1. 4527 .8 | 1. 4646
. 9 | 1. 4305 . 9 | 1. 44 16 .9 | 1. 4530 .9 | 1. 4649
55. 0 | 1. 4307 60.0 | 1.4418 65.0 | 1. 4532 70.0 | 1. 4651
. 1 | 1. 4309 .1 | 1.4420 .1 | 1.4534 .1 | 1.4653
. 2 | 1. 4311 .2 | 1.4423 • .2 | 1. 4537 .2 | 1. 4656
. 3 | 1. 4313 .3 | 1. 4425 .3 | 1. 4539 .3 | 1. 4658
. 4 | 1.4316 .4 | 1.4427 .4 | 1. 4541 .4 | 1. 4661
. 5 | 1. 4318 .5 | 1. 4429 .5 | 1. 4544 .5 | 1. 4663
. 6 | 1. 4320 .6 | 1. 4432 .6 | 1. 4546 .6 | 1. 4666
. 7 | 1. 4322 .7 | 1. 4434 .7 | 1. 4548 .7 | 1, 4668
. 8 || 1. 4325 .8 | 1. 4436 .8 | 1. 4550 .8 | 1. 4671
. 9 || 1. 4327 .9 | 1. 4439 .9 | 1. 4553 .9 | 1. 4673
56. 0 | 1. 4329 61.0 | 1. 4441 66.0 | 1. 4555 71.0 | 1. 4676
... 1 1. 4331 .1 | 1. 4443 ... 1 1. 4557 .1 | 1. 4678
. 2 | 1. 4333 .2 | 1. 4446 .2 | 1. 4560 .2 | 1. 4681
. 3 | 1. 4336 .3 | 1. 4448 .3 | 1. 4562 .3 | 1. 4683
. 4 | 1. 4338 .4 | 1. 4450 .4 | 1. 4565 .4 | 1. 4685
. 5 | 1. 4340 .5 | 1. 4453 .5 | 1. 4567 .5 | 1. 4688
. 6 | 1. 4342 .6 | 1. 4455 .6 | 1. 4569 .6 | 1. 4690
. 7 | 1. 4344 .7 | 1. 4457 .7 | 1.4572 .7 | 1. 4693
. 8 || 1. 4347 .8 | 1. 4459 .8 | 1. 4574 .8 | 1. 4695
. 9 || 1. 4349 .9 | 1, 4462 .9 | 1. 4577 .9 | 1. 4698
656
Circular of the National Bureau of Standards
TABLE 122.-Refractive index of sucrose solutions at 20°C –Continued
Sucrose Rºº. Sucrose Ref * | Sucrose Ref * || Sucrose Ref I’3, C-
y tiye y tºye. by º by iº
weight index, weight index, weight II] ºx, weight index,
70% 70% 70% 70%
% % % %
72.0 1. 4700 75.3 1. 4782 78.6 1. 4865 81.9 | 1. 4951
.1 1. 4703 .4 1. 4784 .7 1. 4868
.2 1. 4705 .5 1. 4787 .8 1. 4871 82.0 | 1. 4954
.3 1. 4708 .6 1. 4789 .9 1. 4873 .1 | 1. 4956
.4 1. 4710 .7 1. 4792 .2 | 1. 4959
.5 1. 4713 .8 1. 4794 79.0 1. 4876 .3 | 1. 4962
.6 1. 4715 .9 1. 4797 .1 1. 4878 .4 | 1. 4964
.7 1. 4717 .2 1. 4881 .5 | 1. 4967
.8 1. 4.720 76.0 1. 4799 .3 1. 4883 .6 | 1. 4970
.9 1. 4722 ... 1 1. 4802 .4 1. 4886 .7 | 1. 4972
.2 1. 4804 .5 1. 4888 .8 | 1. 4975
73.0 1. 4725 .3 1. 4807 .6 1. 4891 .9 1. 4978
.1 1. 4727 .4 1, 4810 .7 1. 4893
.2 1. 4730 .5 1. 4812 .8 1. 4896 83.0 | 1. 4980
.3 1. 4732 .6 1. 4815 .9 1. 4898 .1 | 1.4983
.4 1. 4735 .7 1. 4817 .2 | 1.4985
.5 1. 4.737 .8 1. 4820 80.0 1. 4901 .3 | 1. 4988
.6 1. 4740 .9 1. 4822 .1 1. 4904 .4 | 1. 4991
.7 1. 4742 .2 1. 4906 .5 | 1. 4993
.8 1. 4744 77.0 1. 4825 .3 1. 4909 .6 | 1. 4996
.9 1. 4747 ... 1 1. 4827 .4 1. 4912 .7 | 1. 49.99
- .2 1. 4830 .5 1. 4914 .8 | 1. 5001
74.0 1. 4749 .3 1. 4832 .6 1. 4917 .9 | 1. 5004
... 1 1. 4752 .4 1. 4835 .7 1. 4919
.2 1. 4754 .5 1. 4838 .8 1. 4922 84.0 | 1. 5007
.3 1. 4757 .6 1 4840 .9 1. 4925 .1 | 1. 5009
.4 1. 4759 .7 1. 4843 .2 | 1. 5012
.5 1. 4762 .8 1. 4845 81.0 1. 4927 .3 | 1. 5015
.6 1. 4764 .9 1. 4848 .1 1. 4930 .4 | 1. 501.7
.7 1. 4767 .2 1. 4933 .5 | 1, 5020
.8 1. 4769 78.0 1. 4850 .3 1. 4935 .6 | 1. 0522
.9 1. 4772 ... 1 1. 4853 .4 1. 4938 .7 | 1. 5025
.2 1. 4855 .5 1. 4941 .8 || 1. 5028
75.0 1, 4774 .3 1. 4858 .6 1. 4943 .9 | 1. 5030
.1 1. 4777 .4 1. 4860 .7 1. 4946
.2 1. 4779 .5 1. 4863 .8 1. 4949 85.0 || 1 5033
Polarimetry, Saccharimetry, and the Sugars 657
TABLE 123.-Correction table for determining the percentage of sucrose by means of
the refractometer when the readings are made at temperatures other than 20° Cl

Percentage of sucrose—
Tem-
º 0 5 10 15 20 25 30 35 40 45 50 55 fl0 65 70
Ulre
Subtract from the percentage oſ Sucrose
o C.
10 || 0.50 | 0, 54 || 0.58 || 0. 61 0. 64 || 0.66 || 0. 68 || 0, 70 || 0.72 0.73 || 0.74 || 0.75 0.76 0.78 || 0.79
| 1 46 49 53 55 58 60 62 64 65 | . 66 | . 67 | . 68 . 69 | , 70 . 71
12 43 | .45 || 48 || 50 | 53 54 56 57 || 3 || 5 || 60 | 6 || 6 || 63 | 63
13 | . 37 | . 40 | . 42 | .44 | . 46 | . 48 | . 49 | . 50 | . 51 | . 52 | . 53 | . 54 . 54 | . 55 | . 55
14 | . 33 | . 35 | . 37 . 39 | . 40 | . 41 | . 42 | . 43 | .44 | .45 | .45 .46 | . 46 | . 47 | . 48
1 International Temperature Correction Table, 1936, adopted by the International Commission for
Uniform Methods of Sugar Analysis (Int. Sugar J. 39, 24S, 1937).
658 Circular of the National Bureau of Standards
TABLE 124.—Refractive indea of sucrose solutions at 28°C."
Refracti • ive fractive
sº | * Rºve Rºve Rºw
- 8 8
weight n; nº nº n;
% % %
0. 0 | 1. 33219 5. O | . 33941 0. 0 | . 34691 5. 0 . 35470
... 1 . 33233 . 1 . 33956 . 1 . 34.706 . 1 . 35486
. 2 | . 33248 2 | . 33971 , 2 . . .34722 ... 2 . 35502
. 3 | . 33262 . 3 | . 33985 . 3 | . 34.737 . 3 . 35.518
. 4 | . 33.276 . 4 | . 34000 . 4 | . 34752 . 4 . 35534
, 5 | . 33291 . 5 | . 340 15 , 5 34767 . 5 . 35550
. 6 33305 6 34030 . 6 | . 34783 , 6 . 35566
. 7 33319 . 7 | . 34045 . 7 | 34798 7 . 35582
8 . 33333 . 8 | . 34059 8 | . 34.813 ... 8 . 35598
. 9 , 33348 . 9 | . 34074 , 9 | . 34829 , 9 . 35.614
1. 0 | . 33362 . 0 | . 34089 . 0 | . 34844 . 0 . 35630
. 1 . 33376 . 1 . 34104 . I | . 34859 . 1 . 35646
. 2 | . 3339.1 . 2 | . 34119 . 2 | . 34875 ... 2 . 35662
3 | . 33405 . 3 | . 34134 . 3 | . 34891 . 3 . 35678
. 4 | . 33420 . 4 | . 34149 . 4 | . 34906 . 4 . 35694
. 5 | . 33434 . 5 | . 34,163 . 5 | . 34921 . 5 . 35711
. 6 | . 33448 , 6 | . 341.78 . 6 | . 34937 ... 6 . 35.727
, 7 | . 33463 . 7 . 34193 . 7 | . 34953 7 . 357.43
8 | . 33477 . 8 | . 34208 . 8 || 34968 ... 8 . 357.59
, 9 || , 3.3492 . 9 . 34.223 , 9 | . 34983 . 9 35775
2. 0 | . 33506 . () | . 34.238 , () 34999 . () 1. 35791
... 1 . 33520 ... I . 34.253 . 1 . 350 15 ... I . 35807
. 2 | . 33535 . 2 | 34268 . 2 | . 35.030 ... 2 . 35823
. 3 | . 33549 . 3 | . 34.283 . 3 | . 35046 . 3 . 35.840
. 4 | . 33.563 . 4 | . 34.298 . 4 | . 35061 ... 4 . 35856
5 33577 . 5 | . 34.313 . 5 35077 . 5 . 35872
6 | . 33592 . 6 | . 34327 . 6 35093 ... 6 . 35888
7 | . 33606 . 7 | . 34342 . 7 | . 35108 7 . 35904
. 8 | . 33620 . 8 | . 34357 . 8 35124 ... 8 . 35921
. 9 | . 33635 . 9 | . 34372 . 9 35139 . 9 . 35937
3. 0 | . 33649 0 | . 34387 . 0 | . 35155 . 0 1. 35953
. 1 . 33664 . 1 . 34402 . 1 . 35171 ... 1 . 35969
. 2 . . 33678 . 2 | . 344.17 . 2 | . 351.86 ... 2 . 35986
. 3 | . 33693 . 3 | . 34.432 . 3 | . 35202 ... 3 . 36002
. 4 | . 33707 . 4 | . 34447 . 4 | . 35218 . 4 . 36019
. 5 | . .33722 . 5 | . 34463 . 5 | . 35233 . 5 . 36035
. 6 . 33737 . 6 | . 34.478 . 6 | . 35249 ... 6 . 36051
. 7 | . 33751 . 7 | . 34493 . 7 | . 35265 ... 7 . 36068
8 . 33766 . 8 34508 . 8 . 35281 ... 8 . 36084
. 9 . 33780 . 9 | . 34523 . 9 | . 35296 . 9 . 36101
4. 0 | . 33.795 . 0 | . 34538 . 0 | . 35312 . 0 1. 36117
. 1 . 338.10 . 1 . 34553 . 1 | . 35328 . 1 . 36133
. 2 | . 33824 . 2 | . 34569 . 2 | . 35344 . 2 . 36150
. 3 | . 33839 . 3 | . 34584 . 3 | . 35359 . 3 . 36167
. 4 | . 33853 . 4 | . 34599 . 4 | . 35375 ... 4 . 361.83
. 5 33868 . 5 | . 34615 . 5 | . 35391 . 5 . 36199
. 6 . 33883 . 6 | . 34630 . 6 35407 ... 6 . 36216
. 7 | . 33897 . 7 | . 34645 . 7 | . 35423 7 . 36233
. 8 | . 33912 . 8 34660 . 8 | . 35438 ... 8 . 36249
. 9 | . 33926 . 9 34676 . 9 | . 35.454 . 9 . 36265
1 Int. Sugar J. 39, 23S (1937).
Polarimetry, Saccharimetry, and the Sugars
659
TABLE 124.—Refractive index of sucrose solutions at 28° C.—Continued
Sucrose
b
Refractive
index
Sucrose
b
Reſractive
index
Sucrose
Refractive
index
Sucrose
Refractive
index
wºnt nº wºnt n; wºnt nº wºnt n;
% % % %
20. 0 1. 36282 25. 0 l. 3712 30. 0 1. 3800 35. 0 1. 3890
... 1 . 36299 . I . 3714 ... 1 . 3802 . 1 . 3892
, 2 , 36315 ... 2 , 3715 ... 2 . 3804 ... 2 . 3894
. 3 . 36332 . 3 . 37.17 . 3 . 3805 ... 3 . 3895
. 4 . 36348 . 4 . 3719 . 4 . 3807 ... 4 . 3897
. 5 . 36365 . 5 3721 . 5 . 3809 . 5 . 3899
... 6 . 36.382 ... 6 . 3722 ... 6 . 381.1 ... 6 . 3901
... 7 . 36398 ... 7 . 3724 ... 7 . 3813 7 . 3903
... 8 . 36415 ... 8 . 37.26 ... 8 . 3814 ... 8 . 3904
. 9 . 36431 . 9 . 3727 . 9 . 3816 . 9 . 3906
21. 0 1. 36448 26. 0 1. 3729 31. () 1. 3818 36. 0 1. 3908
. 1 . 36465 . 1 | . 3731 . 1 . 3820 . 1 . 3910
... 2 . 36481 ... 2 , 3733 ... 2 . 38.21 ... 2 . 3912
. 3 . 36498 ... 3 . 3734 . 3 . 38.23 3 . 3914
. 4 . 365.15 ... 4 . 3736 . 4 . 38.25 ... 4 . 3916
. 5 . 36531 . 5 . 3738 . 5 . 3827 ... 5 . 3917
... 6 . 36548 ... 6 . 3740 ... 6 . 3828 ... 6 . 3919
7 . 36565 ... 7 . 3742 7 . 3830 ... 7 . 3921
... 8 . 36582 ... 8 . 3743 ... 8 . 3832 ... 8 . 3923
. 9 . 36598 . 9 . 3745 . 9 . 3833 . 9 . 3925
22. 0 1. 366.15 27. 0 1. 3747 32. 0 1. 3835 37. 0 1. 3927
... 1 . 36632 . 1 . 3749 . 1 . 3837 . 1 . 3929
... 2 . 36648 ... 2 . 37.50 ... 2 . 3839 ... 2 . 3931
. 3 . 36665 . 3 . 3752 . 3 . 3840 ... 3 . 3933
. 4 . 36682 . 4 . 3754 . 4 . 3842 ... 4 . 3935
. 5 . 36699 . 5 . 3756 ... 5 . 3844 ... 5 . 3937
... 6 . 36715 ... 6 . 3757 ... 6 . 3846 ... 6 . 3938
... 7 . 36732 7 . 37.59 7 . 3848 ... 7 . 3940
... 8 . 36749 ... 8 . 3761 ... 8 . 3849 ... 8 . 3942
. 9 . 36.765 . 9 . 3762 . 9 . 3851 . 9 . 3944
23. 0 1. 36782 28. 0 1. 3764 33. 0 1. 3853 38. 0 1. 3946
. 1 . 36799 . 1 . 3766 ... 1 . 3855 . 1 . 3948
... 2 . 36816 ... 2 . 3768 ... 2 . 3857 ... 2 . 3950
. 3 . 36833 . 3 . 3769 ... 3 . 3858 . 3 . 3952
. 4 . 36850 . 4 . 3771 . 4 . 3860 ... 4 . 3954
... 5 . 36867 . 5 . 3773 ... 5 . 3862 . 5 . 3956
... 6 . 36884 ... 6 . 3775 ... 6 . 3864 ... 6 . 3958
... 7 . 36901 ... 7 . 37.77 ... 7 . 3866 ... 7 . 3960
... 8 . 36918 ... 8 . 3778 ... 8 . 3867 ... 8 . 3962
. 9 . 36935 . 9 . 3780 . 9 . 3869 . 9 . 3964
24. 0 1. 36952 29. 0 1. 37.82 34. 0 1. 3871 39. 0 1. 3966
. 1 . 3697 . 1 . 3784 . 1 . 3873 . 1 . 3968
... 2 . 3699 . 2 . 3786 ... 2 . 3875 2 . 3970
. 3 . 3700 . 3 , 3787 ... 3 . 3877 ... 3 , 3972
. 4 . 3702 ... 4 . 3789 ... 4 . 3879 ... 4 . 3974
. 5 . 3704 ... 5 . 3791 . 5 . 3881 . 5 . 3975
... 6 . 3705 ... 6 . 3793 ... 6 . 3882 ... 6 . 3977
... 7 . 3707 ... 7 . 3795 ... 7 . 3884 ... 7 . 3979
... 8 . 3709 ... 8 . 3796 ... 8 . 3886 ... 8 . 3981
. 9 . 3710 . 9 . 3798 . 9 , 3888 . 9 . 39.83
660
Circular of the National Bureau of Standards
TABLE 124.—R/fractive inder of sucrose solutions at 28° C.—Continued
sº "º" || sº "º" || sº "º" || sº | *
weight n28 weight n°8 weight n28 weight n28
I) D D
O 97, % %
40. 0 1. 3985 45. 0 1. 4083 50. 0 1. 41.87 55. 0 1. 4293
. 1 3987 ... 1 . 4085 ... 1 . 41.89 ... 1 . 4295
... 2 . 3989 ... 2 . 4087 ... 2 . 419.1 ... 2 . 4297
. 3 . 3990 ... 3 . 4089 . 3 . 4193 ... 3 . 4300
... 4 . 3992 ... 4 . 4091 . 4 . 4195 . 4 . 4302
. 5 . 3994 ... 5 4093 . 5 . 4 197 . 5 . 4304
... 6 . 3996 ... 6 . 4096 ... 6 . 41.99 ... 6 . 4306
... 7 . 3998 ... 7 . 4098 ... 7 . 420.1 ... 7 , 4308
... 8 . 3999 ... 8 . 4100 ... 8 . 4203 ... 8 . 4311
. 9 . 4001 . 9 . 4102 . 9 . 4205 . 9 . 4313
41. 0 1. 4003 46. 0 1. 4104 51. () 1. 4207 56. 0 1. 4315
... 1 . 4005 ... 1 . 4106 . 1 . 4209 . 1 , 4317
... 2 4007 ... 2 . 4108 ... 2 . 4211 ... 2 . 4319
... 3 . 4009 ... 3 . 4110 . 3 . 4213 . 3 . 4322
. 4 . 4011 ... 4 . 4112 . 4 . 4215 . 4 . 4324
. 5 . 4013 ... 5 . 4114 . 5 . 4217 ... 5 . 4326
... 6 . 4015 ... 6 . 41.16 ... 6 . 4220 ... 6 . 4328
... 7 . 4017 ... 7 . 4118 ... 7 . 4222 ... 7 . 4330
... 8 . 4019 ... 8 . 4120 ... 8 . 4224 ... 8 . 4333
. 9 . 4021 . 9 . 4122 . 9 . 4226 . 9 . 433.5
42. 0 1. 4023 47. 0 1. 4124 52. () 1. 4228 57. 0 1. 4337
... 1 . 4025 ... 1 . 4126 ... I . 4230 ... 1 . 4339
... 2 . 4027 ... 2 . 4128 ... 2 . 4232 ... 2 . 434)
. 3 . 4029 ... 3 . 4130 . 3 . 4235 ... 3 . 4344
... 4 . 4031 ... 4 . 4132 . 4 . 4237 . 4 . 4346
. 5 . 4033 . 5 . 4135 . 5 . 4239 . 5 . 4348
... 6 . 4035 ... 6 . 41.37 ... 6 . 4241 ... 6 . 4350
. 7 . 4037 7 . 4139 ... 7 . 4243 7 . 4352
... 8 . 4039 ... 8 . 4141 ... 8 . 4246 ... 8 . 4355
. 9 . 4041 . 9 . 4143 . 9 . 4248 . 9 . 4357
43. 0 1. 4043 48. 0 1. 4145 53. () 1. 4250 58. () 1. 4359
. 1 . 4045 ... 1 . 4147 ... 1 . 4252 ... 1 . 4361
... 2 . 4047 ... 2 . 4149 ... 2 . 4254 2 . 4364
... 3 . 4049 ... 3 . 41.51 ... 3 . 4256 . 3 . 4366
... 4 . 4051 ... 4 . 4153 . 4 . 4258 ... 4 . 4368
... 5 . 4053 ... 5 . 4155 . 5 . 4261 ... 5 . 43.71
... 6 . 4055 ... 6 . 41.58 ... 6 . 4263 ... 6 . 4373
7 . 4057 ... 7 . 4160 ... 7 . 4265 ... 7 . 4375
... 8 . 4059 ... 8 . 4.162 ... 8 . 4267 ... 8 . 4377
. 9 . 4061 . 9 . 4164 . 9 . 4269 . 9 . 4380
44. 0 1. 4063 49. 0 1. 4166 54. 0 1. 4271 59. 0 1. 4382
... 1 . 4065 ... 1 . 4168 ... 1 . 4273 . 1 . 4384
... 2 . 4067 ... 2 . 4170 ... 2 . 4275 ... 2 . 4386
... 3 . 4069 . 3 . 4172 . 3 . 4278 . 3 . 4388
... 4 . 4071 . 4 . 4174 . 4 . 4280 . 4 . 4390
... 5 . 4073 . 5 . 4177 . 5 . 4282 . 5 . 4393
... 6 . 4075 ... 6 . 4179 ... 6 . 4284 ... 6 . 4395
7 . 4077 ... 7 . 4181 ... 7 . 4286 ... 7 . 4397
... 8 . 4079 ... 8 . 41.83 ... 8 . 4289 ... 8 . 4399
. 9 . 4081 . 9 . 41.85 . 9 . 429 | . 9 . 4401
Polarimetry, Saccharimetry, and the Sugars
661
TABLE 124.—Refractive index of surcose solutions at 28° C.—Continued
Refractive
Refractive
Refractive
Refractive
sº index sº S(* index sº index sº )S(\ index
weight n28 weight n28 weight m28 weight n28
D D D D
% % % %
60. 0 1. 4403 65. 0 1. 451 7 70. 0 1. 4635 75. 0 1. 4758
. 1 . 4405 ... 1 . 4519 ... I . 4637 . 1 . 4761
... 2 . 4408 ... 2 . 4522 ... 2 . 4640 ... 2 . 4763
. 3 . 4410 ... 3 . 4524 ... 3 . 4643 . 3 . 4765
. 4 . 4412 ... 4 . 4526 ... 4 . 4645 ... 4 . 4768
. 5 . 4415 . 5 . 4529 . 5 . 4647 . 5 , 4771
... 6 . 4417 ... 6 . 4531 ... 6 . 4650 ... 6 , 4773
... 7 . 4419 ... 7 . 4533 ... 7 . 4653 ... 7 , 4775
... 8 . 4421 ... 8 . 4535 ... 8 . 4655 ... 8 , 4778
. 9 . 4424 . 9 . 4538 . 9 . 4657 . 9 . 478.1
61. 0 1. 4426 66. 0 1. 4540 71. 0 1. 4660 76. 0 1. 4783
. 1 . 4428 ... 1 . 4542 ... 1 . 4662 . 1 . 4786
... 2 . 4431 ... 2 . 4545 ... 2 . 4665 ... 2 . 4788
. 3 . 4433 ... 3 . 4547 ... 3 . 4667 . 3 . 4791
. 4 . 4435 ... 4 . 4550 . 4 . 4670 ... 4 . 4793
. 5 . 4437 . 5 . 4552 . 5 . 4672 . 5 . 4796
... 6 . 4440 ... 6 . 4554 ... 6 . 4674 ... 6 . 4799
... 7 . 4442 7 . 4557 ... 7 . 4677 ... 7 . 4801
... 8 . 4444 ... 8 . 4559 ... 8 . 46.79 ... 8 . 4804
. 9 . 4447 . 9 . 4562 . 9 . 4682 . 9 . 4806
62. 0 1. 4449 67. 0 I. 4564 72. 0 1. 4684 77. 0 1, 4809
... 1 . 4451 . 1 . 4566 ... I . 4687 . 1 . 4811
... 2 . 4453 ... 2 . 4569 ... 2 . 4689 ... 2 . 4814
... 3 . 4456 ... 3 . 4571 ... 3 . 4691 ... 3 , 4817
. 4 . 4458 ... 4 . 4574 ... 4 . 4694 ... 4 . 48.19
. 5 . 4460 . 5 . 4576 ... 5 . 4697 . 5 . 4821
... 6 . 4462 ... 6 . 4578 ... 6 . 4699 ... 6 . 4824
... 7 . 4464 ... 7 . 4581 ... 7 . 470] ... 7 , 4827
... 8 . 4467 ... 8 . 4583 ... 8 . 4704 ... 8 . 4829
. 9 . 4469 . 9 . 4586 . 9 . 4707 . 9 . 4831
63. 0 1. 4471 68. () 1, 4588 73. 0 1. 4709 78. 0 1. 4834
. 1 . 4473 ... 1 . 4590 . 1 . 4711 . 1 , 4837
... 2 . 4476 ... 2 . 4593 ... 2 . 4714 ... 2 , 4839
. 3 . 4478 . 3 . 4595 . 3 . 4716 . 3 . 4842
... 4 . 4480 ... 4 . 4598 . 4 . 4719 ... 4 . 4844
. 5 . 4483 . 5 . 4600 . 5 . 4721 ... 5 , 4847
... 6 . 4485 ... 6 . 4602 ... 6 . 4723 ... 6 . 4850
... 7 . 4487 ... 7 . 4605 ... 7 . 4726 ... 7 . 4852
... 8 . 4489 ... 8 . 4607 ... 8 . 4728 ... 8 . 4855
. 9 . 4492 . 9 . 4610 . 9 . 473] . 9 . 4857
64. 0 1. 4494 69. 0 1. 4612 74. 0 1. 4733 79. 0 1. 4860
... 1 . 4496 ... 1 . 4614 . 1 . 4735 . 1 . 4862
... 2 . 4499 ... 2 . 4617 ... 2 . 4738 ... 2 . 4865
. 5 . 4501 . 3 . 4619 ... 3 . 4741 . 3 . 4860
. 4 . 4503 ... 4 . 4621 ... 4 . 4743 . 4 . 4877
. 5 . 4505 . 5 . 4623 . 5 . 4745 . 5 . 4872
... 6 . 4508 ... 6 . 4626 ... 6 . 4748 ... 6 . 4874
... 7 . 4510 7 . 4628 ... 7 . 4751 ... 7 . 4877
... 8 . 4512 ... 8 . 4630 ... 8 . 4753 ... 8 . 4879
. 9 . 45.15 , 9 . 4633 , 9 . 4755 . 9 . 4882
662
Circular of the National Bureau of Standards
TABLE 124.—Refractive inder of surcose solutions at 28° C.—Continued

Sucrose
y
weight
Refractive
index
28
ID
§
81.
1. 4884
. 4887
. 4889
. 4892
. 4894
. 4897
. 4900
. 4902
. 4905
. 4907
1. 4910
. 4913
. 4915
Refractive
ivy efractive
sº index sº * € sº R #ex
weight ID weight D weight D
% % %
81. 3 1. 4918 82. 6 1. 4953 83. 9 1. 4987
. 4 . 4921 ... 7 . 4955
... 5 . 4923 ... 8 . 4958 84. 0 I. 4990
... 6 . 4926 . 9 . 4960 ... 1 . 4993
... 7 . 4929 ... 2 . 4995
... 8 . 4932 83. 0 1. 4963 ... 3 . 4998
. 9 . 4934 ... 1 . 4966 . 4 . 5000
... 2 . 4968 ... 5 . 5003
82. 0 1. 4937 ... 3 . 4971 ... 6 . 5006
... 1 . 4940 ... 4 . 4974 7 . 5008
... 2 . 4942 . 5 . 4977 ... 8 . 5011
. 3 . 4945 ... 6 . 4979 . 9 . 5013
. 4 . 4947 7 . 4982
. 5 . 4950 ... 8 . 4985 85. 0 1. 5016
TABLE 125.-Correction table for determining the percentage of sucrose by means of
the tropical model of refractometer when the readings are made at temperatures
other than 28° C 1
Percentage Of Sucrose
Tein- --- - - - - - - - -
tºr:l- () 5 I() 15 20 25 30 35 40 45 5() 55 60 (35 7()
ture
Subtract from percentage of sucrose
oC
20 || 0.57 | (). 59 || 0. 60 0.61 || 0.62 0.63 0.63 || 0. 64 0. 64 || 0.64 0. 64 (). 64 0. 64 (). 65 0.65
21 . 51 . 52 | . 53 | . 53 | . 55 | . 55 | . 55 | . 56 | . 56 | . 56 | . 56 | . 56 | . 56 . 57 . 57
22 | .44 | . 46 . 46 . 46 | . 47 | . 48 | . 48 . 49 | . 48 | . 48 | . 48 . 48 | . 48 | . 49 . 49
23 . 37 . 38 . 39 | . 39 | . 40 | . 40 | . 40 | . 41 . 41 | . 41 . 40 | . 40 | . 40 | . 41 . 41
24 .30 . 31 . 32 | . 32 .32 | . 32 . 32 . 33 | . 33 . 33 , 32 | . 32 | . 32 .33 . 33
25 | . 23 | . 23 | . 24 | . 24 | . 24 | . 24 . 24 | . 25 | . 25 | . 25 | . 24 | . 24 | . 24 | . 24 . 24
26 | . 16 | . 16 | . 16 | . 16 | . 16 | . 16 . 16 | . 17 | . 16 | . 16 | . 16 | . 16 | . 16 | . 16 . 16
27 | . 08 . . 08 . . 08 . . 08 . . 08 . . 08 . . 08 . . 08 . . 08 . . OS | . 08 . . 08 . . 08 . . 08 . (38
Add to percentage of sucrose
29 || 0.09 || 0, 09 || 0.09 || 0.09 || 0.09 || 0.09 || 0.09 0.08 || 0.08 0.08 || 0.08 || 0.08 || 0.08 || 0, 08 || 0.08
30 | . 17 | . 17 | . 17 | . 17 | . 17 . 17 . 17 | . 17 | . 17 | . 17 | . 17 | . 17 | . 17 . 17 . 17
31 , 26 | . 26 | . 26 | . 26 | . 26 | . 26 | . 26 25 | . 25 | . 25 | . 25 | . 25 | . 25 , 25 . 25
32 | . 35 | .35 | . 35 | . 35 | . 35 | . 34 . 34 | . 34 | . 34 . 34 | . 34 | . 33 | . 33 . 33 . 33
33 | . 44 .44 .44 | .44 | .44 .43 . 43 | . 43 | . 43 | . 42 | . 42 | . 42 | . 42 | . 42 . 42
34 | . 54 | . 54 | . 53 | . 53 | . 53 . 52 . 52 | . 52 | . 52 | . 51 | . 51 | . 50 | . 50 50 . 50
35 | . 63 | . 63 | . 63 | . 62 | . 62 | . 62 | . 61 . 61 . 6] 60 | . 60 | . 59 | . 59 . . 59 . 58
36 | . 73 | . 73 | . 73 | . 72 | . 72 | . 72 | . 71 | . 70 | . 70 | . 69 | . 69 | . 68 . 67 . 67 , 67


1 Int. Sugar J. 39, 24s (1937).
Polarimetry, Saccharimetry, and the Sugars
663
TABLE 126.-Determination of percentage of sucrose in sugar solutions from the
readings of the Zeiss immersion refractometer at 20° C 1
Scale
read-
ing 2 at
20° C.
44
Su-
20 CI’OSé
weight
%
1. 33299 || 0
1. 33320 . 15
1. 33358 . 41
1. 33397 . 68
1. 33435 . 94
1. 33474 | 1. 21
1. 33513 | 1. 48
1. 33551 | 1. 74
1. 33590 2. 01
1. 33628 || 2. 27
1. 33.667 2. 54
1. 33705 || 2: 80
1. 33743 || 3. 07
1. 33781 || 3. 33
1. 33820 | 3. 59
1. 33858 || 3. 85
1. 33896 || 4. 11
1. 33934 4.36
1. 33972 || 4, 62
1. 34010 || 4. 88
1. 34048 5. 14
1. 34086 || 5. 40
1. 34124 || 5. 65
1. 34.162 5. 91
1. 34.199 || 6. 16
1. 34237 || 6.41
1. 34275 6. 66
1. 34.313 || 6.91
1. 34350 | 7. 16
1. 34388 7. 41
1. 34426 || 7. 66
Scale
read-
ing at
20° C
75
:
i.:
i
.
Sucrose
n°9 y
weight
%
. 34463 7. 9 |
. 34500 8. 15
. 34537 8. 39
. 34575 8. 64
. 34.612 8. 89
. 34.650 9. 13
34687 9. 38
. 34724 9. 62
. 34761 9. 86
. 34798 || 10. 10
. 34836 || 10. 34
. 34873 || 10. 58
. 34910 || 10. 82
. 34947 | 11. 06
. 34984 || 11. 30
. 35021 | 11. 54
. 35058 || 11. 78
. 35095 | 12. 01
. 35132 | 12. 25
. 35169 || 12. 48
. 35205 || 12. 72
. 35242 | 12. 95
. 35279 || 13. 18
. 35316 || 13. 41
. 35352 | 13. 64
. 35388 || 13. 87
. 35425 || 14. 10
. 35461 || 14. 33
. 35497 || 14. 56
. 35533 14. 79
. 35569 || 15. 01
Scale
read-
ing at
20° C.
105
nº
Su-
CFOSé
weight
33
55
86
57
88
i
3
6
O
3
8
- - - - - - - - -
1 The values in this table were calculated by J. A. Mathews from the five-place indices of Schönrock as
given by Landt, Z. Ver. deut. Zucker-Ind. 83, 692 (1933).
2 The scale readings refer only to the scale of arbitrary units proposed by Pulfrich, Z. angew. Chem. p.
1168 (1899). According to this scale, 14.5=1.33300, 50.0=1.34650, and 100.0= 1.36464. If the immersion re-
fractometer used is calibrated according to another arbitrary scale, the readings must be converted into
refractive indices before this table is used to determine the percentage of Sugar.
664
Circular of the National Bureau of Standards
TABLE 127.-Schönrock temperature corrections for determining refractive inder
of sucrose solutions by means of a refractometer when readings are made at
temperatures other than 20° C.
PERCENTAGE of sucrose
Tem-
pera- 0 5 10 15 20 25 30 35
ture - -
Subtract from observed index
o C
10 (). 00072 0. 00080. O. 00089| 0, 00097.| 0 00105|0. 001140. 001220. 00131
11 066 07.3 08.1 089 095 103 1 11 119
12 060 067 073 080 086 093 100 106
13 0.53 059 065 07.1 076 082 088 093
14 047 052 057 062 066 071 0.76 08.1
15 039 044 048 052 055 059 063 068
16 032 036 039 042 045 048 051 055
17 025 027 0.29 032 034 037 039 041
18 0.17 0.19 020 022 023 025 0.26 028
19 009 009 010 011 011 013 013 014
Add to observed index
21 || 0 00009| 0 00010| 0, 0001 || 0 0001 1 0, 000120. 00013|0. 00013|0. 00014
22 018 020 021 023 024 0.26 027 028
23 028 0.29 032 035 037 039 041 043
24 038 041 043 046 049 052 055 0.58
25 048 052 055 059 062 066 069 07.3
26 058 063 067 0.71 0.75 080 084 088
27 069 0.75 079 084 089 094 099 103
28 080 086 092 097 102 108 113 119
29 092 099 105 111 117 123 129 135
30 104 111 118 124 131 137 144 150
31 117 124 131 138 155 152 1.59 166
32 129 137 144 152 160 167 175 182
33 142 151 158 167 175 183 191 199
34 155 164 172 181 190 198 207 215
35 169 178 137 196 205 214 223 232
36 182 192 202 211 221 230 240 249
Polarimetry, Saccharimetry, and the Sugars
665
TABLE 127.-Schönrock temperature corrections for determining refractive indea:
of sucrose solutions by means of a refractometer when readings are made at
temperatures other than 20° C–Continued
PERCENTAGE OF SUCROSE
Tem-
pera- 40 45 50 55 60 65 70
ture !
Subtract from observed index
o C
10 O. 00139|| 0 001.47| 0.00156|| 0 00164] O. 001.72 0.00180 0. 001.89
11 126 133 141 148 155 163 170
12 113 119 126 132 138 145 151
13 099 105 111 116 121 127 133
14 086 090 095 100 104 109 114
15 0.72 0.75 079 083 087 0.91 095
16 058 061 064 067 070 * 073 0.76
17 043 046 048 051 053 055 057
18 0.29 031 032 034 035 037 038
19 0.15 0.15 016 0.17 0.17 0.19 0 1 0
Add to observed index
21 0 00015 0.00015| 0 00017| 0, 00017| 0, 00018 0.00019 0.00019
22 030 031 033 034 036 037 038
23 045 047 049 051 054 055 057
24 060 063 066 069 072 074 077
25 076 079 083 087 090 093 097
26 092 096 100 104 108 112 116
27 108 113 117 122 127 131 135
28 124 129 134 140 145 15 155
29 140 146 151 158 163 169 175
30 156 163 169 176 182 188 195
31 173 180 187 194 201 207 215
32 190 197 205 212 220 227 235
33 207 215 223 231 239 247 255
34 224 232 24] 249 258 266 275
35 241 250 259 268 277 286 295
36 259 268 278 287 296 306 315
666 Circular of the National Bureau of Standards
TABLE 128.- Method of obtaining — log T
Log T for values of T from T = 1.00 to T=0.100 may be taken directly from
the table of mantissas below. For this range the characteristic is zero. Log T
for values of T between T = 0.100 and T=0.0000 is obtained by taking from the
table of mantissas the decimal part of the logarithm corresponding to the number
without regard to the position of the decimal point in the number and adding
thereto the appropriate characteristic.
It should be remembered that if T is expressed as the fractional part of unity
Mantissas for numbers from 0 to 1
T 0 1 2 3 4
0. 10 | – 0. 00000 || – 0.99568 || – 0. 99.140 | – 0. 987.16 || –- 0. 98.297
. 11 || –. 95.861 — . 95468 —. 95078 — . 94692 —. 94310
. 12 || ---. 92082 | – 91721 | ––. 91364 — . 91009 – 90658
. 13 || ---. 88606 || –. 88273 || –. 87943 — . 87615 ––. 87290
. 14 – .. 85.387 | –. 85078 || – 84771 — . 84466 —. 84164
. 15 –. 82391 | –. 82102 || –. 81816 || ––. 81531 — , 81248
. 16 – .. 79.588 — . 79317 | –- 79.048 – 78781 — . 78516
17 | –. 76955 | –. 76700 | –. 76447 | –. 76195 — 75945
. 18 || –. 74473 ––. 74232 | – 73.993 || –. 73755 —. 73518
. 19 || – , 72125 — . 71897 | –. 71670 — . 71444 — , 71220
. 20 | – 69897 || — . 69680 | –. 69465 | –. 69.250 — . 69037
21 | –. 67778 ––. 67572 –. 67566 – . 67162 — . 66959
. 22 — . 65758 — . 65561 | –. 65365 — , 65.170 —. 64975
23 —. 63827 —. 63639 || –. 63451 | – 63264 —- . 63078
. 24 || – . 6 1979 || –. 61798 || – , 61618 — . 61439 —-. 61261
. 25 | –. 60206 || – 60033 || – 59860 | – 59688 —. 59517
. 26 — 585.03 | – 58336 — . 581.70 | –. 58004 — . 57840
. 27 | –. 56864 || –. 56.703 || – 56543 —. 56384 —. 56225
. 28 –. 55.284 —. 55129 | –-. 54975 — . 54821 —-. 54668
. 29 — 53760 | –. 53611 || –. 53462 – 53313 —. 531.65
30 –. 52288 –. 52143 | –. 51999 || --. 51856 —. 51713
. 31 –. 50864 | –. 50724 —. 50585 | –. 50446 —-. 50307
. 32 — . 49485 | –. 49349 | – . 49214 — . 490.80 ---. 48945
. 33 || – , 48149 —. 48017 | ––. 47886 –. 477.56 — . 4.7625
. 34 || –. 46852 —. 46725 | –. 46597 | – 46471 –. 46344
. 35 | –. 45593 —. 45469 | –. 45.346 | –- . 45223 —. 45 100
. 36 || --. 44370 —. 44249 — . 44129 || ---. 44009 —. 43890
. 37 | – 43180 —-. 43063 | – 42946 | –. 42829 —-. 42713
. 38 || –. 42022 | —. 41908 —. 41794 | –. 41680 —. 41567
. 39 –-. 40894 | –. 40782 — . 40671 — . 40561 — 40450
. 40 | ––. 39794 | –. 39686 —. 39577 | – , 39469 —. 39362
. 41 || – 38722 | —. 38616 || –-. 38510 | – , 38405 — , 38300
. 42 || ---. 37675 — . 37572 — . 37469 || -- . 37.366 — . 37.263
. 43 | – 36653 | –. 36552 | —. 36452 | ––. 36351 — 36251
. 44 —. 35655 | –. 35556 | –. 35458 –. 35.360 — , 35262
. 45 —. 34679 —. 34582 —. 34486 || –. 34390 —. 34294
. 46 | –. 33724 —. 33630 | –. 33536 | –. 33442 —. 33.348
. 47 | –-. 32790 — . 32698 || – .. 32606 || – 32514 —. 32422
. 48 || –. 31876 || –. 31785 | – 31695 || – 31605 —. 31515
. 49 —. 30980 | –. 30892 | – 30803 || – 30715 — . .30627
. 50 | —. 30.103 || –. 30016 || –. 29930 | –. 29843 — . .297.57
. 51 —. 29.243 | –. 29158 || –. 290.73 || –. 28.988 — . 28904
. 52 — . 28.400 | — . 28316 — . 28.233 || –. 28150 — . 28067
. 53 | – 27572 | –. 27.491 || – . 27.409 || –. 27327 —. 27246
. 54 — . 26761 | – . 26680 | – . 26600 — . 26520 — , 26440
Polarimetry, Saccharimetry, and the Sugars 667
TABLE 128.—-Method of obtaining —log T-Continued
the characteristic is equal to minus the number of zeros between the decimal point
and the first significant figure. Thus, the characteristic of T=0.5 is 0; that of
T=0.005 (0.5 percent) is —2; etc.
ExAMPLE 1.--To find —log T if T = 0.00543. In the table of mantissas the
mantissa corresponding to 543 (disregarding the position of the decimal point)
is – 0.26520. Since there are two zeros between the decimal point and the first
significant figure the characteristic is –2. Adding these, log T- –2.26520 and
— log T = + 2.2652.
Mantissas for numbers from 0 to 1—Continued
T 5 (; 7 8 9
0. 10 — 0. 97881 — 0. 97469 — 0. 97062 — 0. 96658 — 0. 96.257
. 11 — . 93930 —. 93554 —. 93.181 —. 928.12 —. 92445
. 12 —. 90309 — . 89963 — . 89620 — . 89.279 —. 8894.1
. 13 —. 86967 —. 86646 —. 86.328 — . 86012 — . 85699
. 14 —. 83863 —. 83565 —. 83268 —. 82974 ––. 82681
, 15 —. 80967 —. 80688 — . 80410 ––. 80.134 --. 79860
. 16 — , 78252 –. 77989 –. 77728 ––. 77.469 —. 77211
. 17 — , 7.5696 —. 75449 — , 7.5203 —. 74958 —. 74715
. 18 —. 73283 —. 73049 — . 72816 — . 72584 — . 72354
. 19 —. 70992 —-. 70774 —. 70553 —. 70333 —. 701 15
. 20 —. 68825 —. 68613 — . 68403 —. 68.194 —. 67985
. 21 —. 66756 — . 66555 —. 66354 — 66154 —. 65956
. 22 —. 64782 —. 64589 — . 64397 —-. 64207 ––. 64016
. 23 —. 62893 —. 62709 —. 62525 —. 62342 —. 62160
. 24 — . 61083 — , 60906 —. 60730 — . 60555 —. 60380
. 25 —. 59346 —. 591.76 —. 59007 —. 58838 —. 58670
. 26 — . 57675 — . 57512 — . 57349 — . 57187 —. 57025
. 27 —. 56067 —. 55909 — , 55752 ––. 55596 —. 55440
. 28 —. 54516 —. 54363 —. 54.212 — . .54061 —. 53910
. 29 —. 53018 — , 52871 ––. 52724 —. 52578 —. 52433
. 30 —. 51570 — , 51428 ––. 51286 —. 51145 —. 51004
. 31 —. 50169 —. 50031 — . 49894 —- . 497.57 — . 496.21
. 32 —. 48812 — . 48678 ––. 48545 —. 484.13 ––. 48280
. 33 —. 47496 —. 47366 — . 47237 —. 47108 —. . 46980
. 34 —. 46218 —-. 46092 — , 45967 —. 45842 —. 45717
. 35 —. 44977 —. 44.855 —. 44733 —. 44612 —. 44491
. 36 —. 43771 —. 43652 ---. 43533 —. 434.15 — , 43297
. 37 — . 42597 —. 42481 --. 42366 —. 42251 —. . 42136
. 38 —. 41454 —. 41341 — . 41229 —. 41117 — , 4 1005
. 39 —. 40340 —. 40230 —. 40121 ––. 40012 –. 39903
. 40 ––. 39.254 —. 39147 —. 39041 –. 38934 ---. 38828
. 41 —. 38195 ––. 38091 — . 37986 — . 37882 – , 37.779
. 42 — . 37161 — . 37059 —. 36957 ---. 36856 –. 36754
. 43 —. 36151 —. 36051 — . .35952 ––. 35853 —. 35754
. 44 —. 35164 —. 35067 —. 34969 – 34872 — . .34775
. 45 —. 34.199 —. 34104 —. 34008 —. 33.913 —. 338.19
. 46 —. 33255 —. 33.16.1 —. 33068 —. 32975 —. 32883
. 47 —. 32331 — . .32239 —. 32148 —. 32057 ---. 31966
. 48 —. 31.426 —. 31336 —. 31247 ––. 31.158 —. 31069
. 49 —. 30539 —. 30452 —. 30364 –. 30.277 — , 30.190
. 50 —. 29671 —. 29.585 — . .294.99 —. 29416 — . .29328
. 51 — . 288.19 —. 28735 —. 28651 — . 28567 —. 28483
. 52 — . .27984 —. 27901 —. 278.19 – 27737 —. 27.654
. 53 —. 27165 —. 27084 — , 27003 — . 26922 —. 2684.1
. 54 —. 26360 —. 26281 — . 26201 —. 26122 —. 26043
668 Circular of the National Bureau of Standards
TABLE 128.— Mantissas for numbers from 0 to 1—Continued
T 0 1 2 3 4
. 55 —. 25964 —. 25.885 — . 25806 —. 25.727 —. 25649
. 56 —. 25.181 —. 25 104 —. 25026 – 24949 —. 24872
. 57 —. 24413 —. 24336 —. 24260 |. — . 24.185 —. 24.109
. 58 — . .23657 —. 23582 —. 23508 —. 23433 —. 23359
. 59 —. 22915 —. 2284.1 –. 22768 —. 22695 —. 22621
, 60 —. 22.185 —. 22113 —. 22040 — , 21968 —. 21896
. 61 —. 21467 —. 21396 —. 21325 —. 21254 —. 21 183
. 62 — . 20761 ––. 20691 —. 20621 — . 2055.1 —. 20482
. 63 — . 20066 —. 19997 — , 19928 — . 19860 — . 19791
. 64 — . 1938.2 —. 19314 — . 19246 — . 1917.9 —. 19111
65 —. 18709 —. 18642 —. 18575 —. 18509 —. 18442
66 —. 18046 —. 17980 —. 17914 —. 17849 — . 17783
67 —. 17393 — , 17328 —. 17263 —. 17198 —. 17134
. 68 —. 16749 —. 16685 —. 16622 —. 16558 —. 16494
. 69 —. 1611.5 —. 16052 —. 15989 —. 15927 —. 15864
70 —. 15490 —. 15428 —. 15366 —. 15304 —. 15243
71 —. 14874 —. 14813 —. 14752 —. 14691 —. 14630
72 —. 14267 —. 14206 —. 14.146 —. 14086 —. 14026
73 —. 13668 —. 13608 — . 13549 —. 13490 —. 13430
74 — . 13077 —. 13018 — . 12960 — . 12901 —. 12843
. 75 —. 12494 —. 12436 — . 12378 - . 12321 —. 12263
. 76 —. 11919 —. 11862 —. 1 1805 —. 11748 —. 1 1691
77 —. 11351 —. 11295 —. 11238 -- . 11182 —. 11126
. 78 —. 107.91 —. 10735 —. 106.79 —. 10624 — . 10568
... 79 —. 10237 —. 10182 — , 101.27 —. 100.73 —. 10018
. 80 — . 09691 — 09637 —. 095.83 —. 09528 —. 09474
. 81 —. 091.51 — 09098 —. 09046 —. 0.8991 — . 08939
. 82 — . 08619 —. 0.8566 — . 08513 —. 08460 — . 08407
. 83 — . 08092 —. 08040 —. 07988 — . 0.7935 —. 07883
. 84 —. 0.7572 —. 07520 — . 07469 —. 07417 — . 07366
85 — . 07058 —. 07007 —. 06956 —. 06905 —. 06854
86 —. 06550 —. 06500 —. 06449 — . 06399 — . 06349
87 — 06048 — . 05998 —. 05948 —. 05899 —. 0.5849
88 —. 05552 —. 05502 — . 05453 — . 05404 — . 05355
89 — . 05061 —. 05012 —. 04964 —. 0491.5 —. 04866
90 —. 04576 —. 04528 —. 04479 —. 04431 —. 04383
91 —. 04096 —. 04048 — . 04001 –. 03953 — . 03905
92 — . 03621 —. 03574 —. 03527 —. 03480 —. 03433
93 —. 03152 — . 03105 — . 03058 — . 03012 —. 02965
94 —. 02687 —. 02641 — . 02595 —. 02549 —. 02503
95 —. 02228 —. 02182 — . 021.36 —. 02091 —. 02045
. 96 — , 0.1773 — , 0.1728 — , 0.1682 — , 01637 —. 0.1592
. 97 —. 01323 — . 01278 — . 01233 — . 01189 —. 01.144
. 98 —. 00877 —. 00833 —. 00789 —. 00745 — . 00700
. 99 —. 00436 — , 0.0393 —. 00349 | . — 00305 —. 00261
Polarimetry, Saccharimetry, and the Sugars
669
TABLE 128.- Mantissas for numbers from 0 to 1—Continued
5 6 7 8 9
. 55 —. 25571 —. 25493 ––. 25414 —. 25337 — . 25259
. 56 —. 24.795 —. 24718 —. 24642 — . 24565 —. 24489
. 57 —. 24033 —. 23958 —. 23882 — , 23807 —. 23732
. 58 —. 23284 —. 23210 —. 23136 —. 23062 —. 22988
. 59 —. 22548 —. 22475 —. 22403 — , 22330 — . 22257
. 60 —. 21824 —. 21753 —. 21681 —. 21610 —. 21.538
. 61 —. 21112 —. 21042 –. 20971 —. 20901 —. 20831
. 62 —. 204 12 — . 20343 — . 20273 —. 20204 —. 20135
. 63 — . 19723 — . 19654 — . 19586 — . 19518 —. 19450
. 64 —. 19044 – , 18977 —. 18910 —. 18842 –. 18776
. 65 —. 18376 —. 18310 —. 18243 –. 18.177 —. 18111
. 66 –. 17718 — , 17653 — , 17587 — , 17522 — . 17457
. 67 –. 17070 —. 17005 —. 16941 –, 16877 —. 16813
. 68 —. 16431 –. 16368 —. 16304 —. 16241 —. 16178
, 69 — . 15802 —. 15739 –. 15677 —. 15614 —. 15552
. 70 —. 15181 —. 15120 —- . 15058 —. 14997 — , 14935
. 71 —. 14569 —. 14509 —. 14448 —. 14388 —. 14327
. 72 —. 13966 —. 13906 —. 13847 –. 13787 – 13727
. 73 —. 13371 —. 13312 —. 13253 —. 13194 —. 13136
. 74 —. 12784 — . 12726 —. 12668 — . 12610 —. 12552
. 75 —. 12205 —. 12148 —. 12090 —. 12033 —. 11976
76 —. 11634 —. 11577 —. 11520 —. 11464 —. 11407
77 —. 11070 —. 11014 —. 10958 —. 10902 —. 10846
. 78 —. 105.13 —. 10458 —. 10403 —. 10347 —. 10292
. 79 — . 0.9963 — . 09909 — 09864 — 09799 — . 09745
. 80 — 09420 — 09366 — . 093 13 – 09.259 — 09205
... 81 — . 08884 — . 08831 —. 08778 —. 08725 — . 08672
. 82 —. 08355 — . 08302 —. 08249 —. 0.8197 —. 08145
. 83 — 07831 – 07779 – 0.7727 – 07676 — . 07624
. 84 —. 07314 — . 07.263 —. 07212 —. 07160 — . 07109
. 85 — . 06803 — . 06753 — . 06702 —. 06651 — . 06601
. 86 — . 06298 —. 06248 — . 06198 —. 061.48 — . 06098
. 87 . 05799 — . 05750 —. 0.5700 —. 05651 — . 05601
. 88 —. 05306 — . 05257 —. 05208 —. 05159 —. 05110
. 89 —. 04818 — . 04769 — . 04721 —. 04672 — . 04624
. 90 —. 04335 —. 04287 —. 04239 —. 04.191 —. 04144
. 91 — . 03858 — . 038.10 —. 03763 —. 03716 — . 03668
. 92 —. 03386 —. 03339 —. 03292 —. 03245 —-. 03198
. 93 —. 02919 — 02872 —. 02826 — 02780 — . 02733
. 94 — 02457 —. 02411 —. 02365 — 02319 — , 0.2273
. 95 — 02000 —. 01954 — . 0.1909 —. 01863 — . 01818
. 96 —. 01547 —. 01502 —. 01457 —. 01412 —. 0.1368
. 97 —. 01100 — . 0.1055 —. 0.1011 —. 00966 — . 00922
. 98 — . 00656 —. 00612 —. 00568 — . 0.0524 —. 0.0480
. 99 —. 00218 — . 001.74 — . 00130 –. 00087 —. 00043
323414°—42—–44
670
Circular of the National Bureau of Standards
[All data computed from weights in air with brass weights.
TABLE 129.-Refractive inder of levulose solutions
Immersion readings
are referable solely to the scale of arbitrary units proposed by Pulfrich (Z.
angew. Chem., p. 1186, 1899).
1.34650, and 100.0= 1.36464]
According to this scale, 14.5 = 1.33300; 50.0=

Levu-
lose
by
weight
%
ii
7, 20
Zeiss
immer-
sion
read-
ing,
20° C.
7, 25
D
i
:::
ii
i
i
1.
1.
1.
I
1.
1.
1
I
I
:
&*ege
:
:
3.3252
33393
33535
33678
33822
33967
34113
34260
34408
34557
34.707
34857
35009
35162
35316
35470
35626
35.783
35942
36102
36262
36.425
36588
. 36753
. 37258
. 374.26
. 37598
1. 37771
1
1
. 37945
. 381.21
Zeiss
immer-
sion
read-
ing,
25° C.
Levu-
— A77. lose
Af 0 by
*" ||weight
X10-5 %
96 32
98 33
100 34
102 35
104 36
106 37
108 38
| 10 39
112 40
115 41
117 42
119 43
121 44
123 45
125 46
127 47
129 48
132 49
135 50
137 51
139 52
142 53
146 54
148 55
151 56
154 57
157 58
16] 59
164 60
166 61
169 62
172 63
i.:
i
. 38385
. 38564
. 38745
. 38927
. 39111
. 39295
. 39481
. 39.669
. 39858
. 40048
. 40239
. 40432
. 40625
. 40821
. 41018
. 41216
. 41415
. 41616
. 41818
. 42021
. 42226
. 42432
. 42640
. 42848
. 43058
. 43270
. 43482
. 43696
. 43913
. 44130
. 44348
. 44569
1
1
1
1
I
I
1
1.
1
I
i
. 38297
. 38476
.38655
. 38836
. 39018
. 39.201
. 39386
39573
. 39760
. 39949
40140
40331
40524
40718
40914
411] 1
41309
41509
4.1710
41912
42117
42322
42528
42736
42945
43156
43368
43581
43797
44014
44232
. 44451
218
219
22]
223
22
226
Levu-
lose
by
weight
77
20
4479
450]
4524
4547
4569
4592
4615
4638
4661
4684
i
:
4708
4731
4755
4779
4803
4827
4851
4875
4900
4924
4949
4974
4999
5024
5049
5074
5100
5126
:
i:
:
1. 5151
1. 5.177
1. 5203
1. 5230
7m 25
I)
. 4467
Polarimetry, Saccharimetry, and the Sugars
671
[Recommended for use in the calibration of viscometers.
TABLE 130.-Viscosity, in centipoises, of sucrose solutions
These values are based
upon measurements made at the National Bureau of Standards on solutions
containing 20, 30, 40, 50, 60, 65, 70, and 75 percent of sucrose by weight in
vacuo, using the value 1.0050 centipoises for water at 20° C, and are estimated
to be accurate to about 0.1 percent]
Temperature in * C
Sucrose
by
weight -
in
V8 CUiO 15 16 17
%
20 2. 268 2. 200 2. 135
1 2. 372 2. 300 2. 232
2 2. 484 2.408 2. 336
3 2. 605 2. 525 2.448
4 2. 736 2. 650 2. 569
5 2.877 2. 786 2. 700
6 3.029 2.933 2.841
7 3. 195 3.092 2.994
8 3. 374 3.264 3. 159
9 3, 569 3.452 3.340
30 3. 782 3. 656 3. 536
1 4.014 3. 879 3. 750
2 4. 267 4. 122 3. 983
3 4. 545 4. 388 4. 239
4 4.851 4. 681 4. 519
5 5. 189 5.005 4. 829
6 5. 561 5. 361 5. 170
7 5.974 5. 755 5. 548
8 6. 433 6. 194 5. 967
9 6. 943 6. 680 6.432
40 7. 515 7. 226 6.952
1 8. 158 7. 839 7. 535
2 8. 882 8. 527 8. 190
3 9. 698 9. 303 8. 929
4 10. 62 10. 18 9. 762
5 11. 67 11. 17 10. 70
6 12.86 12. 30 11. 77
7 14, 22 13. 59 13.00
8 15. 78 15. 07 14. 40
9 17, 59 16. 77 16.00
50 19. 67 18. 74 17.87
I 22. 10 21.03 20.03
2 24.94 23. 70 22.54
3 28. 28 26.84 25, 50
4 32. 23 30. 55 28.98
5 36. 92 34.95 33. 11
6 42. 54 40. 21 38.04
7 49. 32 46. 55 43.97
8 57. 55 54.23 51. 13
9 67. 63 63. 61 59.88
60 80.09 75.18 70. 63
l 95.62 89. 57 84.00
2| 1 15, 1 107. 6 100. 7
3| 139.9 130. 5 121.8
4|| 171. 6 159.7 148. 7
5| 212.8 197. 5 183. 5
6| 266, 8 246.9 228.8
7| 338, 7 312.5 288.7
8| 435. 6 400. 5 368.9
9| 568. 0 520. 6 477. 8
70|| 752. 2 687. 0 628. 3
1| 1013. 921. 3 839. 4
2. 1389. 1258. 1141.
3| 1943. 1752. 1582.
4 2778. 2492. 22:39.
5| 4067. 3628. 3243.
18 19 20 21
2. 073. 2. 014 | 1.957 1. 902
2. 166. 2. 104 2. 044 1.986
2. 267 2, 201| 2. 137| 2.077
2. 375] 2. 305 2. 238| 2. 174
2. 491 2.417| 2.346| 2. 278
2. 617| 2. 538; 2.463| 2.391
2. 753| 2.669; 2. 589| 2.512
2.900| 2.81.1 2. 725| 2. 644
3.060 2.964| 2.873| 2. 786
3. 233| 3. 131 3.034 2.94.1
3.422| 3. 312|| 3. 208| 3. 109
3. 627| 3. 510| 3. 398| 3. 291
3. 851 3. 725; 3. 605 3.490
4.096 3.960. 3. 831|| 3. 708
4. 365. 4. 219 || 4.079| 3.946
4. 662| 4. 503|| 4.352; 4. 208
4. 989| 4.817| 4. 653| 4.496
5. 350, 5, 162| 4.984| 4.814
5. 751 || 5. 546 5. 351 5. 165
6. 195| 5. 971 5. 758, 5. 555
6.692| 6.445. 6. 210| 5.988
7. 248| 6.976 6. 717| 6. 471
7.872| 7. 570 7. 284| 7. 013
8. 574| 8. 239| 7.922 7. 620
9. 366|| 8.992 8. 639| 8.304
10. 26 9, 844| 9.449| 9.074
11. 28 || 10.81 10. 37 9.947
12.44 || 11.91 11. 41 || 10.94
13. 76 || 13. 17 | 12.60 | 12. 07
15. 28 14. 61 13.97 || 13. 37
17. 04 || 16. 27 | 15. 54 || 14.86
19.08 18. 20 17.36 | 16. 58
21.46 | 20.44 | 19.48 18, 58
24. 24 || 23.06 || 21.95 || 20.91
27. 51 26. 14 || 24.86 || 23. 64
31. 39 29, 79 28, 28 || 26, 88
36.01 || 34. 12 || 32.36 || 30, 71
41. 56 || 39. 32 || 37. 23 || 35. 29
48. 26 || 45. 59 || 43. 10 | 40. 79
56.42 53. 21 50. 22 || 47. 45
66.43 || 62.54 58.93 || 55.58
78. 85 74.09 | 69. 68 || 65. 59
94. 34 || 88.47 | 83.03 || 78.02
113. 9 || 106.6 99.80 | 93. 57
138. 7 | 129. 5 | 121. 0 || 113.2
170. 7 || 158.9 || 148. 2 || 138. 3
212. 3 197. 2 | 183.3 || 170. 7
267. 0 || 247. 4 || 229.4 || 213. 0
340. 2 || 314. 2 | 290. 5 || 269. 0
439. 2 | 404.3 || 372. 7 || 344. 0
575. 5 || 527. 9 || 485. 0 || 446. 2
766. 0 || 700. 1 || 640.8 587. 5
1037. 944. 3 || 860.9 || 786. 1
1431. 1297. 1178. 1071.
2016 1818. 1643. 1488.
2904 2606. 2344. 2112.
22 23 24 25
1.850. 1. 800| 1.752. 1. 706
1.932 1.879| 1.828| 1.780
2.019 1.963 1. 909| 1.858
2. 112| 2.053: 1.997.| 1. 943
2. 213| 2. 151 2.091 || 2,034
2. 322 2. 255] 2, 192| 2. 131
2.439| 2.369| 2. 301 || 2, 237
2. 566 2.491 || 2.419| 2, 351
2. 703: 2. 623| 2. 547| 2.474
2. 852| 2, 767 2. 685| 2.608
3.014| 2.923 2.836| 2.752
3. 189| 3.092] 2.999| 2.910
3. 381 3. 276|| 3. 176|| 3.081
3.590 3.478. 3. 370 3. 267
3.818] 3. 697; 3. 582. 3. 471
4. 070| 3.939| 3.814; 3. 694
4. 347| 4, 205| 4. 070|| 3, 940
4. 652| 4.498| 4.350| 4, 210
4.988, 4.820 4, 660|| 4. 507
5. 362| 5, 178| 5.003|| 4, 836
5. 776|| 5. 574| 5. 382| 5, 200
6. 238 6. 0.16|| 5. 805| 5, 604
6. 755| 6.510| 6, 277| 6,056
7.335| 7.064| 6.807. 6. 561
7. 987 7.685| 7, 399| 7. 127
8. 721 8.385| 8.067| 7, 764
9. 551 | 9. 176|| 8.820) 8.482
10.49 10. 07 9. 674| 9. 296
11. 57 11.09 || 10. 65 10. 22
12.80 12. 26 || 11. 76 11, 28
14. 21 13. 60 | 13.03 || 12.49
15. 84 || 15, 15 || 14, 50 | 13, 88
17. 73 16.94 | 16. 19 15.48
19.94 19.02 | 18. 16 17.35
22. 52 | 21.46 | 20. 47 | 19. 53
25. 57 24, 33 || 23. 17 22.09
29. 17 | 27. 73 26.37 25, 1()
33. 47 31. 77 30, 18 28.69
38. 63 || 36.61 || 34. 73 || 32.97
44.87 || 42.45 | 40.21 || 38. 11
52.47 || 49. 57 || 46.87 || 44, 36
61. 81 58. 29 55.02 || 51.98
73. 37 69. 07 || 65. ()8 || 61.37
87.82 82. 51 77. 58 || 73.02
106.0 99. 41 || 93.28 87.62
129. 2 | 120.9 || 113. 2 | 106. I
159. 1 148. 4 || 138. 7 | 129. 7
198. 0 | 184. 3 || 171. 7 || 160. 2
249.3 || 231.4 215. 0 | 200. 1
317. 9 || 294. 2 | 272.6 || 252.9
411. 1 || 379. 2 || 350. 2 | 323.9
539. 3 || 495. 8 || 456. 4 || 420. 7
719. 0 || 658. 6 || 604. 1 || 554.9
975. 6 | 890. 0 | 813. 1 || 744. 1
1349. 1225. 1115. 1016.
1906. 1723. 1560. 1415.
672
Circular of the National Bureau of Standards
TABLE 131. –Viscosity, in centipoises, of sucrose solutions at 20° C relative to
water (m/mhao)


Sucrose
y .0 .1 .2 .3 .4 .5 .6 .7 .8 .9
weight
%
0 | 1.000 | 1.026 | 1.053 1. 082 1. 113 1. 145 1. 179 1. 215 1. 253 1. 293
10 1. 336 1. 381 1. 430 1. 481 1. 535 1. 5.93 1.655 1. 721 1. 791 1. 866
20 1. 947 2.034 || 2. 127 2. 227 2. 334 2.451 2. 576 2. 712 2. 859 3. 019
30 || 3, 192 || 3.381 || 3. 587 3.812 4. 059 4. 330 4. 630 4.959 5. 324 5. 729
40 6, 18 6. 68 7.25 7.88 8. 59 9. 40 10.31 11. 35 12. 54 13.90
50 | 15, 47 17, 28 19. 38 21. 87 24. 73 28. 14 32. 20 37. 05 42.89 49. 97
60 58.64 || 69.33 || 82.62 99. 30 120.4 147.4 182.4 228. 3 289. 1 371. 0
70 |482.6 637. 6 856. 6 1, 172 1, 635 2, 332 ---------|---------|---------|---------
Polarimetry, Saccharimetry, and the Sugars
673
TABLE 132.—Viscosity, in centipoises, of sucrose solutions from 0° to 40° C in
5-degree intervals
[These values are based on the same measurements mentioned in table 130]
Sucrose Temperature in * C
y
weight
in vacuo 0 5 10 15 20 25 30 35 40
%
20 3. 806 3. 157 2.658 2. 268 1.957 1. 706 1. 501 1. 332 1. 190
1 4. 002 3. 314 2. 785 2. 372 2,044 1, 780 1. 564 1. 386 1. 237
2 4. 213 3.482 2.922 2. 484 2. 137 1. 858 1. 631 1. 443 1. 287
3 4. 443 3. 665 3. 069 2. 605 2. 238 1. 943 1. 702 1.505 1. 340
4 4. 691 3. 862 3. 228 2. 736 2. 346 2.034 1. 77 1. 571 1. 397
5 4. 962 4.077 3. 401 2.877 2.463 2. 131 1. 862 1. 642 1.458
6 5. 256 4.309 3. 588 3.029 2. 589 2. 237 1. 952 1. 718 . 1. 524
7 5. 577 4, 562 3. 791 3, 195 2. 725 2, 351 2.048 1. 800 1. 595
8 5. 927 4.838 4.012 3. 374 2.873 2.474 2. 152 1. 889 1, 671
9 6. 311 5. 140 4. 253 3. 569 3.034 2. 608 2, 264 1.984 1. 753
30 6, 735 5, 470 4. 516 3. 782 3. 208 2. 752 2. 386 2.088 1.842
1 7. 194 5. 831 4. 803 4.014 3. 398 2.910 2. 518 2, 199 1.937
2 7. 703 6. 227 5. 118 4. 267 3. 605 3.081 2. 661 2, 319 2. 040
3 8. 268 6. 666 5. 464 4. 545 3. 831 3.267 2.816 2.451 2. 152
4 8. 899 7. 153 5. 847 4.851 4. 079 3. 471 2.985 2. 593 2. 272
5 9. 605 7. 696 6. 272 5, 189 4. 352 3. 694 3. 170 2. 748 2. 403
6 10. 38 8, 289 6. 738 5. 561 4. 653 3. 940 3. 375 2.919 2. 547
7 11. 26 8.963 7. 261 5.974 4. 984 4. 210 3. 596 3. 103 2. 703
8 12. 25 9, 716 7, 844 6. 433 5. 351 4, 507 3. 840 3.306 2.874
9 13. 36 10. 56 8. 494 6. 943 5. 758 4, 836 4. 110 3.529 3.059
40 14.65 11. 52 9. 229 7. 515 6, 210 5, 200 4. 405 3. 772 3. 262
1 16. 11 12.61 10. 06 8, 158 6. 717 5, 604 4. 733 4. 041 3. 484
2 17. 79 13.85 11.00 8.882 7.284 6. 056 5. 098 4. 339 3. 731
3 19.71 15. 27 12. 06 9. 698 7. 922 6. 561 5. 504 4. 670 4. 003
4 21.91 16.88 13. 27 10. 62 8. 639 7. 127 5. 958 5.038 4. 306
5 24.45 18. 73 14. 65 11. 67 9.449 7, 764 6. 466 5.449 4.642
6 27.40 20.86 16. 22 12.86 10. 37 8. 482 7. 037 5, 909 5. 017
7 30, 81 23. 31 18. 03 14, 22 11. 41 9. 296 7. 681 6.425 5. 437
8 34.80 26, 17 20. 12 15. 78 12. 60 10. 22 8.409 7. 008 5. 908
9 39. 49 29. 50 22. 55 17. 59 13. 97 11. 28 9. 236 7. 666 6. 439
50 45. 05 33. 41 25. 39 19.67 15. 54 12.49 10. 18 8. 416 7. 040
1 51. 64 38.02 28.68 22. 10 17.36 13. 88 11. 26 9, 267 7. 722
2 59.51 43.48 32. 57 24.94 19. 48 15.48 12, 50 10, 24 8. 498
3 68.99 49.99 37, 17 28. 28 21, 95 17, 35 13.94 11. 36 9.387
4 80. 48 57.82 42.68 32. 23 24.86 19. 53 15. 60 12. 66 10.41
5 94.51 67. 29 49. 25 36. 92 28, 28 22. 09 17. 55 14. 16 11. 58
6 111, 8 78.82 57. 20 42. 54 32. 36 25. 10 19.82 15.91 12.95
7 133. 2 93.00 66.86 49. 32 37. 23 28.69 22. 51 17. 96 14.54
8 160. 1 110.3 78. 70 57. 55 43. 10 32, 97 25. 70 20. 37 16.41
9 193.9 132.4 93. 35 67. 63 50. 22 38, 11 29, 50 23. 23 18.59
60 237, 4 160. 2 111. 7 80. 09 58.93 44.36 34. 07 26.65 21. 19
1 293. 7 195. 6 134. 7 95.62 69. 68 51.98 39, 61 30. 75 24, 28
2 367. 2 241.2 164. 1 115. 1 83. 03 61.37 46.36 35. 71 28.00
3 464. 9 300. 7 201.8 139.9 99.80 73. 02 54.66 41. 76 32.49
4 595.7 379. 2 250. 8 171.6 121.0 87.62 64. 95 49. 19 37.96
5 773. I 484.1 315. 3 212.8 148.2 106. I 77.85 58.39 44.68
6 a 1,020 a 626. 3 a 401. 3 266. 8 183.3 129. 7 94. 12 69. 90 52, 99
7 a 1,365 a 821.9 a 517.3 338.7 229.4 160. 2 114.9 84.42 63. 39
8 a 1,859 a 1,096 a 676. 8 435. 6 290. 5 200. 1 141. 7 103.0 76. 51
9 | a 2, 57 a 1,486 a 898.8 568. 0 372.7 252, 9 176.8 126.9 93.23
70 a 3,654 a 2,052 a1, 214 752. 2 485. 0 323.9 223. 2 158. 1 114.8
1 a 5, 290 a 2, 891 a1, 670 a 1,013 640. 8 420. 7 285.4 199.4 143.0
2 a 7, 847 a 4, 165 a2, 345 a 1,389 860. 9 554.9 370. 2 254.8 180. 2
3 |a|11,960 a 6, 146 a3, 364 a 1, 943 1, 178 744. 1 487. 7 330.2 230. 1
4 |a|18, 770 a 9,310 a4, 941 a2, 778 1, 643 1,016 653. 1 434. 6 298. 1
75 |a31,410 a 14, 530 a7, 454 a4,067 2, 344 1, 415 891. 0 581. 5 392.2

a Values extrapolated below the temperature range of the measurements.
674
Circular of the National Bureau of Standards
TABLE 133. Viscosity, in centipoises, of sucrose solutions, from 45° to 80° C in
5-d
egree intervals
[These values are based in part on the measurements of Bingham and Jackson]'
Su- Temperature in ‘’C
CI’OSe }
by
weight
in 45 50 ñ5 60 65 7() 75 8()
V8, Cll O |
| |
Percent | |
20 | M. º. º. 0 ≤ || 0 &l 0.74 0.58 0.53 || 0 }}
1 1. 11 1. 00 . 9] . 84 77 . . . . . ; . 61
2 1. 15 1. 04 . 95 . 87 | . 79 . 73 | . 68 . 63
3 1. 20 1.09 .98 90 . 82 76 70 . 65
4 1. 25 1. 13 1. 02 93 . 85 .. 79 . 73 . 67
5 1. 30 1. 17 1.06 , 97 . 89 . 82 75 . 70
6 1. 36 1. 22 1. 11 1. 01 . 92 . 85 . 78 . 72
7 1. 42 1. 28 | 1. 16 1. 05 | . 96 | . 88 . 81 . 75
8 1. 49 1. 34 1. 21 1. 10 | 1. 00 | . 92 | . 85 . 78
9 1. 56 1. 40 1. 26 1. 14 | 1. 04 . 96 | . 88 . 81
30 1. º. i. 7 1. 32 1.20 | 1.09 | 1.00 | . 92 . 85
I 1. 72 1. 54 1. 38 1. 25 | 1. 14 | 1. 04 | . 96 . 88
2 | 1. 81 1. 61 1. 45 1. 31 | 1. 19 | 1. 09 | 1. 00 . 92
3 1. 90 1. 70 1. 52 1. 37 | 1. 25 | 1. 14 | 1. 04 . 96
4 2. 01 1. 79 1. 60 1. 44 | 1. 31 | 1. 19 | 1. 09 1. 00
5 2. 12 1. 88 1.68 1. 51 | 1. 37 | 1. 25 1. 14 1. 05
6 2. 24 1.99 1. 77 1. 59 | 1.44 | 1.31 | 1. 19 1. 10
7 2.37 2. 10 | 1. 87 1.68 1.51 | 1.37 | 1. 25 1. 15
8 || 2. 52 2. 22 | 1. 98 1. 77 | 1. 59 | 1. 44 | 1. 31 1. 20
9 2. 68 2. 36 2. O9 1. 87 | 1. 68 | 1. 52 | 1. 38 1. 26
40 || 2. 85 2. 50 | 2. 22 1. 98 || 1. 77 | 1. 60 | 1.45 1. 32
1 3. 03 2. 66 2. 35 2. 09 | 1. 87 | 1. 69 | 1. 53 1. 39
2 3. 24 2. 83 2. 50 2. 22 | 1. 98 || 1. 78 1. 61 1. 46
3 || 3. 46 3. 02 2. 66 2. 36 2. 10 | 1. 89 | 1. 70 1. 54
4 || 3. 72 3. 23 2. 84 2. 51 2. 23 || 2. 00 | 1. 80 I. 63
5 3. 99 || 3. 47 || 3. 03 || 2. 67 || 2. 37 2. 12 | 1.91 1. 72
6 4. 30 || 3. 72 3, 25 2. 86 2. 53 2. 26 2, 02 1. 83
7 4. 65 4. 01 || 3. 49 3.06 2. 71 2. 41 || 2. 15 1. 94
8 : 5. 03 || 4. 33 3. 76 || 3. 29 2. 90 2. 57 2. 30 2. 06
9 5.47 4.69 4.06 3. 54 3. 11 2.75 2.45 2. 20
50 5. 96 || 5. 09 || 4. 39 || 3. 82 3. 35 | 2. 95 || 2. 62 2. 35
1. 6. 51 5. 54 || 4. 76 || 4. 13 3. 61 3. 18 2. 82 2. 51
2 7. 13 6. 05 5. 18 4. 48 3. 90 3. 43 3.03 2. 70
3 7. 85 6.63 5.66 4.88 4. 24 3. 71 || 3. 27 2.90
4 8, 66 || 7. 29 6, 20 5. 32 4.61 4.02 || 3. 53 3, 13
5 9. 60 8. 04 || 6. 81 5. 83 || 5. 03 || 4. 37 || 3. 83 || 3. 38
6 || 10. 7 8. 91 || 7. 52 | 6. 40 || 5. 51 || 4. 77 4, 17 | 3. 67
7 | 11. 9 9. 91 8. 32 || 7. 06 || 6. 05 || 5. 22 4. 55 3. 99
8 || 13. 4 11. 1 9. 25 | 7. 82 6. 67 || 5. 74 4. 98 || 4, 35
9 || 15. 1 12. 4 10. 3 8. 68 7. 38 6. 32 5. 47 || 4, 76
! E. C. Bingham and R. F. Jackson, Bul.
BS 14, 59 (1918) S298.
Polarimetry, Saccharimetry, and the Sugars
675
TABLE 133.-Viscosity, in centipoises, of sucrose solutions, from 45° to 80° C in
5-degree intervals—Continued
Su-
CrOSe
by
weight
in
V8,C UlO
*-m- mºs
Percent
60
:
Temperature in *C
45 50 55 60 65 70 75 80
17. 1 14. 0 11. 6 9. 69 8. 19 7. 00 6. 02 5. 22
19. 5 15. 8 13. 0 10. 9 9. 14 7.77 6. 66 5. 76
22. 3 18. 0 14. 8 12. 2 10. 2 8. 66 7. 40 6. 37
25. 7 20. 6 16. 8 13. 8 11. 5 9. 71 8. 25 7. 07
29. 8 23. 8 19. 2 15. 7 13. 0 10. 9 9, 24 7. 89
34. 8 27. 6 22. 1 18. 0 14. 8 12.4 10. 4 8. 84
40. 9 32. 2 25. 6 20. 7 17. 0 14. 1 11. 8 9. 96
48. 5 37. 8 29. 9 24. 0 19. 5 16. 1 13. 4 11. 3
58. 0 44. 8 35. 2 28. 0 22. 7 18, 5 15. 3 12. 8
70. 0 53. 5 41. 7 33. 0 26. 4 21. 5 17, 7 14. 7
85. 2 64. 6 49. 8 39. 1 31. 1 25. 1 20. 5 16. 9
105 78. 6 60. 1 46. 7 36. 8 29. 5 23. 9 19. 6
131 96. 8 73. 2 56. 3 44. 0 35. 0 28. 1 22. 9
165 121 90. 0 68. 6 53. 1 4.1. 8 33. 4 27. 0
210 152 112 84.4 64. 8 50. 5 40. 0 32. 1
272 194 141 105 79. 8 61. 6 48. 3 38. 4
676
Circular of the National Bureau of Standards
TABLE 134.—Herzfeld table of solubility of sucrose in water at different temperatures
e Water corro-
N º Sucrose dis- ſº
w ..., | Sucrose in 100 r ºr sponding to 1 g | 120 g
Temperature g of solution solv º of dissolved dº’, solution |
g g Sll CITOSé
o C g g ſ]
0 64. 18 179. 2 0. 5580 1. 31131
5 64. 87 184. 7 . 5414 1. 31521
10 65. 58 190. 5 . 5249 1. 3 1980
15 66. 30 197. 0 . 5076 1. 32420
20 67. 09 203. 9 . 4904 1. 32905
25 67. 89 211. 4 . 4730 1. 33398
30 68. 70 219. 5 . 4556 1. 33894
35 69. 55 228. 4 . 4378 1. 34430
40 70. 42 238. 1 . 4200 1. 34975
45 71. 32 248. 7 . 4021 1. 35541
50 72. 25 260. 4 . 3840 1. 36130
55 73. 20 273. 1 . 3662 1. 36735
60 74. 18 287. 3 . 34.18 1. 37363
65 75. 18 302. 9 . 3301 1. 38007
70 76. 22 320. 5 . 3120 1. 38681
75 77. 27 339. 9 . 2942 1. 39366
80 78. 36 362. 1 . 2762 1. 40081
85 79. 46 386. 8 . 2585 1. 40807
90 80. 61 415. 7 . 2406 1. 41571
95 81. 77 448. 6 . 2229 1. 42346
100 82. 97 487. 2 . 2053 1. 43154
| Percentages of Sugar calculated from Vacuuin weights.
TABLE 135.--Solubility of sucrose in pure water
[Grams of sugar per 100 g of water]
& Mondain- Hruby-
*|*|*|† ºf ººl ºf ºf ſº,
o Cº
() 183 179. 2 183 163 -----------|----------------------|------------
9 -----------|------------|------ - ... -- it - - - - - - - - - - - - - - - - - - - - - - - 181 l----------|------------
10 190 190. 5 190 179 -----------|------------|----------|------------
15.8 ----------------------------------|---------------------- 196 ----------|------------
20 199 203.9 199 197 -----------|------------ 201 ||------------
25, 6 -----------|------------|-----------|-----------|----------- 211 -- - - - - - - - - - - - - - -
30 213 219. 5 213 216 220 ------------ 218 - - - - - - - - - - - -
30.5 !-----------------------|--------------------------------- 218 l----------|------------
40 231 238. 1 231 239 -----------|------------ 238 - - - - - - - - - - - -
50 255 260. 4 255 266 258 ------------ 233 260
60 285 287, 3 283 296 -- --------|------------ 293 |------------
70 319 320. 5 319 333 330 - - - - - - - - - - - - 330 ------------
80 362 362. 1 362 376 ----------------------- 390 373
90 415 415. 7 415 430 -----------------------|----------|------------
100 471 487. 2 485 497 -----------------------|----------|------------
| Compiled, and bibliography supplied by R. Hruby and V. Kasjanov, Int. Sugar J. 42, 21 (1940); Z.
Zuckerind. Cechoslovak. Rep. 63, 187 (1939).
Polarimetry, Saccharimetry, and the Sugars 677
TABLE 136.-Velocity of crystallization according to Kukharenko, and concentration
- data for pure sucrose in water
(Concentration data for solutions of pure sucrose in water for 10-degree intervals of temperature and for
0.005-intervals of Kukharenko's coefficient of SuperSaturation, k=8/?st, as based upon Herzfeld’s table of
solubilities of sucrose, together with the corresponding velocities of crystallization according to Kukharenko,
where Khas the dimensions mg/(m?Xmin). The “hypothetical yield at 20°, y20," is the quantity given in
column 13 but expressed as a percentage of the total quantity of Sucrose present in 100 g of water, as given
in column 11. The “oversaturation, e20,” in column 15 is the Same quantity expressed as a percentage of
203.9 g, the weight of sucrose required to Saturate 100 g of water at 20°, while “et” in column 16 is the per-
centage of sucrose dissolved in excess of saturation requirements at the temperature tº or, stated as an equa-
tion, et=100(c’—ct)/ct. Therefore, et is the quantity given in column 12 expressed not in grams but as a
percentage of c, when the unit weight of water is 100 g. The Symbols used in the various equations have the
following significance: & &
c’= weight of sucrose dissolved in unit weight of water in the given Solution.
ct= weight of Sucrose required to Saturate unit weight of Water at the temerature t, as derived from
Herzfeld’s table of Solubilities.
m2= total area of the crystal surface, expressed in Square meters.
mg=weight of sucrose deposited on the crystals of m? Surface area, expressed in mg.
min = time required to deposite the given weight of Sucrose, expressed in minutes.
8’= percentage of sucrose contained in the given Solution.
st=percentage of sucrose contained in a Solution which is just Saturated at the temperature t.]


In 100 g of water | Hy- P,
§ –––– #
Formula weights thet- .S.
3. per kilogram of º ical oº: g
5 Q Solution 5 Excess yield 8. Ll ()]] Q
• * -->
$2 * # & at— aſ .S.
* | E O - ‘as .S
5 § ~i=> Öſ) H
# # | 3 || 3 || 3 || 3 || 3 || 3 || 5 | * | 73 t;
à | # à || 3 | # | 3 || 3 | #| | | | | # t 20° | y, en e, #
E- JO UD : GO : H C/D : Hºmº H C
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
Per- Per- | Per- Per- | Per- || Per-
o C k Céºnt g |Moles; Moles Moles|cent | cent M g () g cent cent cent K
1.000| 67.09| 490. 5| 1.96, 18. 27| 20. 23| 9.7| 91.3| 5, 96; 203.9| 0 0 0 0 0 0
1.005| 67.43| 483. 1 | 1.97| 18.08| 20.05| 9.8| 90.2| 6. 05, 207. 0|| 3. 1| 3. 1 1. 5| 1.5| 1.5 40
1. 010| 67.76|| 475. 8 1.98; 17.89| 19.87| 10. 0| 90.0| 6, 14 210. 2' 6. 3| 6. 3| 3.0|| 3. 1 || 3. 1 80
1.015| 68. 10 468. 5| 1.99; 17.71| 19.70|| 10. 1 | 89.9| 6. 24, 213. 4| 9.6| 9.6 4. 5 4. 7| 4.7 120
1.020, 68.43. 461. 3| 2.00. 17. 52| 19. 52; 10.2| 89.8 6. 33| 216. 8 12.9} 12.9| 6. 0. 6. 3| 6. 3| 150
1.025| 68.77|| 454. 2 2.01 || 17.34|| 19. 35| 10.4| 89.6| 6.43| 220.2| 16.3| 16.3| 7.4 8. 0 8.0, 190
1. 030| 69, 10| 447. 1 2.02 17. 15| 19. 17| 10. 5| 89, 5| 6, 53| 223. 7| 19.8| 19.8 8.9| 9.7| 9.7| 230
20 |K 1.035| 69.44|| 440. 1 2.03|| 16.96| 18.99| 10. 7| 89.3| 6.64. 227. 2 23. 3| 23. 3| 10.3| 11. 5| 11.5 275
1. 040|| 69.77| 433. 2 2.04 16. 78| 18.82| 10.8| 89.2| 6.74| 230.8| 27.0| 27.0|| 11.7| 13. 2. 13. 2. 320
1. 045| 70, 11 426.4| 2.05; 16. 59| 18. 64|| 11.0| 89.0|| 6.85| 234.6|| 30.7| 30.7| 13. 1 15, 1| 15. 1 || 360
1.050| 70.45| 419. 5| 2.06| 16.41 18.47| 11.2| 88.8| 6.96. 238.4| 34.5| 34.5| 14.5| 16.9| 16.9| 420
1.055| 70. 78; 412. 8] 2.07 | 16. 22, 18. 29| 11.3| 88.7| 7. 08 242. 2. 38.4| 38.4 15.8| 18.8| 18.8 480
1. 060| 71. 12| 406. 2 2.08 16.03| 18. 11| 11. 5| 88.5| 7, 19| 246.2| 42.3| 42.3| 17.2| 20.8. 20.8| 525
1.065| 71.45| 399.6| 2.09|| 15.85| 17. 94| 11.6| 88.4| 7.31 250.3| 46.4| 46.4| 18. 5; 22.8 22.8 575
1. 070 71.79| 393. 0| 2. 10| 15. 66|| 17.76|| 11.8| 88. 2 7.43, 254. 4| 50. 6|| 50, 6|| 19.9| 24.8. 24.8| 620
1.000 | 68.70: 455. 6. 2.01 || 17.37| 19. 38|| 10.3| 89.7| 6.41 219. 5|| 0 15. 6|| 7. 1 || 7. 7| 0 0
1.005| 69.04| 448. 4| 2.02 17. 18; 19. 20, 10. 5| 89, 5| 6. 52; 223. 1| 3. 6|| 19, 2 8.6| 9.4| 1.6 75
1.010| 69. 39| 441. 2 2.03| 16.99| 19.02 10. 7| 89.3| 6.62. 226.7| 7. 2 22, 8; 10. 1 || 11.2| 3.3 15t)
1.015| 69.73| 434. 1 || 2.04| 16.80| 18.84| 10.8| 89.2. 6. 73 230.4| 10.9| 26. 5| 11. 5| 13.0| 5.0|| 255
1.020 70.07| 427. 1 || 2.05| 16. 61| 18.66|| 11.0| 89.0| 6.84 234. 2, 14. 7| 30.3| 12.9| 14.9| 6.7 380
1.025| 70.42| 420. 1 2.06| 16.42| 18.48| 11.2| 88.8| 6.95| 238.0| 18, 6|| 34. 2. 14.4| 16.8; 8.5| 495
1. 030| 70.76|| 413. 2 2.07| 16. 23| 18. 30| 11. 3| 88.7| 7.07 242.0| 22. 5| 38. 2. 15.8| 18.7| 10.3| 625
30 K 1.035| 71. 11| 406. 4| 2.08 16.04| 18. 12| 11.5| 88.5 7. 19 246. 1| 26.6 42.2 17. 2 20.7| 12, 1 755
1. 040|| 71.45| 399.6| 2.09| 15.85| 17.94| 11. 6| 88.4| 7.31] 250. 2, 30.8; 46.4| 18.5| 22.8| 14.0| 910
1.045 71.79| 392.9 2. 10 15.66, 17.76|| 11.8 88.2 7.44, 254. 5. 35.0|50.7| 19.9| 24.9| 16.0| 1, 115
1.050, 72. 14' 386.3 2. 11| 15.47 17. 58] 12.0 88.0. 7.56] 258.9| 39.4| 55.0 21.3| 27.0. 17.9| 1,320
1.055| 72.48 379.7| 2.12 15.28, 17.40; 12. 2 87.8 7.69| 263.4| 43.9| 59.5| 22.6| 29. 2. 20.0|------
1, 060|| 72.82. 373. 2. 2. 13, 15.09| 17. 22| 12.4| 87.6|| 7.83| 267.9| 48.5| 64. 1| 23.9| 31.4| 22.1|- - - - - -
1.065. 73. 17| 366.8; 2. 14, 14.89| 17.03| 12.6| 87.4 7.97 272.7| 53.2| 68.8 25. 2. 33.8. 24.2|------
| 1.070 73.51] 360. 4. 2. 15 14.70, 16.85 12.8l 87.2 8, 11| 277. 5| 58.0. 73.6l 26.5l 36. 1 26.4|------
678
Circular of the National Bureau of Standards
TABLE 136.-Velocity of crystallization according to Kukharenko, and concentration
data for pure sucrose in water—Continued

1.
40
50
60
70
0
7
0
{
i
()
1
5
i
0
3
5
i
0
6
0
|
0
4
0
r
4-
• -
-
g
420. 1
333.2
385.4
358.9
352.4
327.2
384. 1
356, 9
350.3
324. 5
318. 2
293. 5
348. 1
226.3
In 100 g of water | Hy-
p0-
Formula weights thet- r mº
per kilogram of tiºn ical º
Solution 5 Excess yield -
-->
Cö at— at
: 200 C
- ‘s
tſ)
3 || 3 || 3 || 3 || 3 || * | *
bſ, & -j-> thſ) cº r- * t 200 4/20 £20 € t
; : | | | 7 || > || 5 || 3:
5 6 7 8 9 1() 11 12 13 14 15 16
Per- | Per- Per- | Per- | Per-
Moles Moles|Moles cent cent | M g 9 g cemf cent cemf
2. 06| 16.42; 18.48, 11.1| 88.9| 6.96|| 238. 1| 0 34. 2. 14.4| 16. 0
2.07| 16. 22, 18. 29 11.3| 88.7| 7.07 242. 1| 4 || 38. 3| 15. 8 18.8 1.7
2.08 16.03| 18. 11| 11.5| 88.5| 7. 20. 246. 3| 8. 2 42.5| 17. 2 20.8| 3.5
2. 09 15.83| 17. 92 11. 7 88.3| 7.32 250. 6 12.5| 46.7| 18.6| 22.9| 5.3
2. 10 15. 64. 17.74 11.8 88. 2 7.45 255.0. 16.9| 51. 1, 20.0 25. 1 || 7. 1
2. 11| 15. 44 17. 55 12. 0 88.0| 7. 58) 259.5| 21.4| 55. 6. 21. 1 27.3| 9.0
2. 12 15.25|| 17.37| 12. 2 87.8 7.71 264. 1| 26.0| 60.2 22.8 29. 5; 10.9
2. 13| 15.05| 17, 18| 12.4 87.6| 7.85| 268. 8] 30.7| 64.9| 24. 2. 31.9| 12.9
2. 14, 14.86|| 17.00 12.6 87.4| 7.99| 273.7 35.6 69.8 25.5| 34. 2. 15.0
2. 15|| 14.66|| 16.81| 12.8 87.2| 8. 14| 278. 6; 40. 6| 74.8. 26.8| 36.7| 17.0
2. 16|| 14.46; 16. 62| 13.0| 87.0| 8. 29| 283.7| 45.7| 79.9| 28. 2 39.2| 19.2
2. 17, 14. 27| 16.44 13. 2 86.8 8.44 289.0|| 50.9| 85. 1| 29. 5, 41.8. 21.4
2. 18, 14.07| 16. 25 13.4| 86.6| 8.60| 294. 4| 56.3| 90. 5. 30.8, 44.4|| 23.7
2. 19. 13.88 16.07 13.6 86.4 8. 76' 300. 0. 61.9 96. 1 32.0, 47.1 26.0
2. 20, 13.68|| 15.88 13.9| 86. 1 || 8.93| 305. 7| 67.6|101.8| 33.3| 49.9| 28.4
2. 11 15.40. 17. 51 12. 1| 87.9| 7.61| 260.4| 0 56. 5; 21. 7. 27.7| 0
2. 12 15. 20, 17. 32 12. 2 87.8| 7.75|| 265. 1| 4.8 61.3| 23. 1 || 30, 1| 1.8
2. 13| 15.00|| 17. 13| 12.4| 87.6| 7.89| 270.0 9.6|| 66. 1 || 24. 5| 32.4| 3.7
2. 14|| 14.80| 16.94 12.6| 87.4 8.03 275. 0|| 14.7| 71.2 25.9| 34.9; 5.6
2. 15, 14.60| 16. 75|| 12.9| 87.1| 8. 18| 280.2 19.8 76.3| 27.2. 37.4 7.6
2. 16, 14.40|| 16. 56|| 13. 1| 86.9 8.34| 285. 5. 25. 1ſ 81.6| 28.6|| 40.0 9.6
2. 17| 14, 20 16.37 13.3| 86.7| 8.50. 290.9 30.5| 87.0| 29.9| 42.7| 11.7
2. 19. 14.00. 16. 19, 13.5 86.5 8.66| 296.5, 36. 1| 92.6|| 31. 2 45. 4 13.9
2. 20, 13.80| 16.00 13.7| 86.3| 8.83| 302. 3| 41.9| 98.4| 32.6|| 48.3| 16. 1
2. 21 13. 60 15.81| 14.0| 86.0 9.00, 308. 2 47.8|104.3| 33.9| 51.2| 18.4
2. 22, 13.40|| 15. 62. 14.2| 85.8|9. 18, 314. 3, 53.9|110.4| 35. 1 54. 2. 20.7
2. 23 13. 20, 15.43| 14.4| 85.6 9. 37| 320.6| 60.2|116. 7| 36.4| 57.3| 23. 1
2. 24, 13.00. 15. 24. 14. 7| 85.3| 9.56| 327. 1| 66.7|123. 2. 37.7| 60. 4, 25.6
2.25 12.80 15.05 14.9| 85. 1| 9.75|| 333.8 73.4|129.9| 38.9| 63.7| 28.2
2. 26 12.60. 14.86 15, 2 84.8 9.95 340. 7 80.3||136.8 40.2| 67. 1, 30. 9
2. 17| 14.33| 16. 50 13.2| 86.8| 8.39| 287.3| 0 || 83.4| 29.0| 40.9 0
2. 18, 14. 13 16.31 || 13.4 86.6 8. 56| 292.9 5.6, 89. 1, 30.4| 43.7| 2.0
2. 19, 13.92| 16. 11 || 13. 6| 86.4 8. 73| 298. 8 11. 5| 94.9| 31.8| 46.6|| 4.0
2. 20. 13. 71 | 15.91 || 13.8| 86. 2 8.90|| 304.7| 17.4/100. 9| 33. 1ſ 49.5| 6.1
2. 21 13. 51] 15. 72| 14. 1ſ 85.9| 9.08 310.9 23. 6 107.1| 34.4 52.5| 8.2
2. 22 13.30| 15.52| 14.3| 85.7| 9. 27| 317.3| 30. O 113.4| 35.8 55.6|| 10.4
2. 23| 13. 10 15. 33| 14.6| 85.4 9.46. 323. 8] 36.5|120.0|| 37.1| 58. 8, 12.7
2. 24 12.89. 15. 13| 14.8 85.2 9.66|| 330. 6| 43. 3|126.7| 38.3| 62. 2. 15.1
2.25 12. 69|| 14. 94| 15. 1| 84.9| 9.86|| 337. 6|| 50.3||133. 7 39.6|| 65. 6|| 17. 5
2.27 12.48. 14.75 15.4 84.6|10.07| 344.8 57.5|140.9 40.9| 69. 1, 20.0
2. 28 12. 27| 14. 55 15.6 84.4|10. 29| 352. 3| 65.01148. 4| 42.1| 72.8 22.6
2. 29, 12. 07| 14.36|| 15.9| 84. 1|10. 52| 360. 0| 72.7|156. 1| 43.4| 76. 6. 25.3
2. 30, 11.86|| 14.16|| 16.2 83.8|10. 75 368. 0 80. 7|164. 1 || 44.6 80. 5, 28. 1
2. 31|| 11.66|| 13.97| 16.5 83.5|10. 99 376. 2 88.9|172. 4 45.8| 84.6|| 31.0
2. 32 11.45| 13.77|| 16.8; 83.2|11. 24, 384, 8 97.5|180.9| 47.0 88.8| 33.9
2. 23| 13. 20, 15.43| 14.4| 85.6 9. 36|| 320, 5| 0 |116. 7| 36.4 57.2 || 0
2. 24 12.99. 15. 23| 14.7| 85.3| 9.56|| 327.4| 6.9|123. 5| 37.7| 60. 6 2.1
2. 25 12.78. 15. 03|| 15. 0 85.0 9.77|| 334, 4 13.9||130. 6. 39. 0 64. 1 || 4.3
2. 26|| 12. 57| 14.83. 15. 2 84.8 9.98 341.8. 21.2|137.9| 40.4| 67.6| 6.6
2. 27| 12.35| 14.62. 15.5| 84. 5| 10, 21349. 3. 28.8|145. 5 41.6| 71.4| 9.0
2. 28 12. 14| 14.42| 15.8 84.2|10.43| 357. 2. 36.7|153. 3| 42.9| 75.2| 11.4
2. 29, 11.93| 14. 22, 16. 1 83.9|10. 67| 365. 3| 44, 8, 161.4| 44.2| 79.2 14.0
2. 31|| 11. 72 14. 03] 16.4 83.6|10.92; 373. 7| 53. 1|169.8| 45.4 83.3 16.6
2. 32: 11. 51] 13.83| 16.8| 83.2|11. 17| 382.4| 61.9|178.5| 46.7| 87.6| 19.3
2. 33| 11.30| 13. 63| 17.1. 82.9|11. 43| 391.4| 70.9||187.5' 47.9 92.0] 22. 1
2. 34 11.08| 13.42; 17.4 82.6||11. 71| 400. 8: 80.3|196.9| 49. 1| 96.6|| 25.0
2.35| 10.87| 13. 22 17.8| 82. 2; 11.99| 410. 5 90.0206. 7 50.3| 101.4| 28. 1
2. 36|| 10. 66|| 13.02 18. 1| 81.912. 29| 420.6|100. 1216.8| 51. 5. 106. 3; 31.2
2. 37| 10.45| 12.82. 18.5 81.512. 60| 431. 2; 110.7|227.3| 52.7 111. 5. 34.5
2.38|| 10.24 12.62. 18.9| 81. 112.92 442. 2121.7|238. 3. 53.9| 116.9| 38.0
s
Polarimetry, Saccharimetry, and the Sugars
679
TABLE 137.-Solubility of deactrose in water
Dextrose | Dextrose
Temperature Solid phase in solu- per 100 g
tion 1 of water
oC Percent g
–0. 772--- - - - - - - - - - - Ice-------------------------- 6. 83 |_ _ _ _ _ _ _ _ _ _
–2. 117-------------|----- do----------------------- 16. 65 |_ _ _ _ _ _ _ _ _ _
–2.305- - - - - - - - - - - - - - - - - - do----------------------- 17. 59 |_ _ _ _ _ _ _ _ _ _
- 5.605- - - - - - - - - - ---|----- do----------------------- 33. 02 |_ _ _ _ _ _ _ _ _ _
-5. 3--------------- Cryohydrate- - - - - - - - - - - - - - - - - - 31. 75 - - - - - - - - - -
0. 50--- - - - - - - - - - - - o-C6H12O6. H2O - - - - - - - - - - - - - - - - 35. 2 54, 32
22.98-- - - - - - - - - - - - - - - - - - do----------------------- 49. 37 97. 51
28. 07--- - - - - - - - - - - - - - - - - do----------------------- 52. 99 112. 72
30.00--- - - - - - - - - - - - - - - - - do----------------------- 54. 64 120. 46
35.00--- - - - - - - - - - - - - - - - - do----------------------- 58. 02 138. 21
40. 40-- - - - - - - - - - - - - - - - - - do----------------------- 62. 13 164. 06
41. 45--------------|----- do----------------------- 62. 82 168. 96
45.00---- - - - - - - - - - - - - - - - do----------------------- 65. 71 191. 63
50.00--- - - - - - - - - - - - Transition-- - - - - - - - - - - - - - - - - - - 70. 91 243. 76
28.00--- - - - - - - - - - - - o-C5H12O6-------------------- 67. 0 203
40.00--- - - - - - - - - - - - - - - - - do----------------------- 67. 6 209
45. 00--- - - - - - - - - - - - Metastable- - - - - - - - - - - - - - - - - - - 69. 69 230
55. 22 - - - - - - - - - - - - - - o-C6H12O6 - amºn sº º - - - - - - - - - - - - - - - - 73. 08 261. 7
64. 75--------------|----- do----------------------- 76. 36 323. 0
70. 2.---------------|----- do----------------------- 78. 23 359. 3
80. 5---------------|----- do----------------------- 81. 49 440. 2
90.8---------------|----- do----------------------- 84. 90 562. 3
1 Estimated as anhydrous Sugar.
680 Circular of the National Bureau of Standards
TABLE 138.-Solubility of levulose in water
Computed by means of the equation C=0.15010.3t?–0.814t-H331.023 derived
by the method of least squares from three observed values, as follows: 1
C= g of
Percentage •
t levulose/100 Molecular weights used
of levulose g of water
oC
20 78. 94 374. 78 Levulose - - - - - - 180. 1572
40 84. 34 538. 63 Water___ _ _ _ _ _ _ 18.0162
55 88. 10 740. 32 -
1 BS Sci. Pap. 20, 587 (1926) S519.
TABLE 138.-Solubility of levulose in water—Continued
Basis of computation
Number of molecu- Concentra-
Tem- || Composition W lar weights in 1 kg Mºjac. tion of levu-
pera- ater of solution I lose in—
ture to 1
—| kg.
levu-
1 kg | 100 g
º Water lose º Water| Total º Water| Of Of
º º Water | Water
Per- | Per- Per- | Per-
oC cent cent g Moles | Moles | Moles | cent cent | Moles g
20----- 78. 94, 21. 06| 266. 8| 4, 38 11. 69| 16. 07| 27. 26|| 72. 74 20. 80|374. 78
21----- 79. 17 20. 83| 263. 1. 4. 39| 11. 56|| 15.95 27. 52| 72.48 21. 10|380. 12
22- - - - 79. 41| 20. 59| 259. 3| 4. 41| 11. 43' 15. 84] 27.84| 72. 16. 21. 41|385. 77
23----- 79. 66 20. 34. 255. 3| 4. 42| 11. 29, 15. 71| 28, 13| 71. 87| 21. 74|391. 71
24___ _ _ 79. 92 20. 08 251. 3| 4. 44 11. 15 15. 59| 28.48 71. 52 22. 09|397. 95
25----- 80. 18. 19. 82 247. 2 4.45| 11. 00. 15.45| 28. 80| 71. 20. 22.45|404. 49
26_____| 80. 44| 19, 56. 243. 1. 4. 46|| 10. 86. 15. 32. 29. 11| 70.89| 22.83411. 33
27----- 80. 71 | 19. 29| 239. O 4. 48| 10. 71 || 15. 19| 29. 49| 70. 51] 23. 23|418. 47
28__ _ _ _ 80. 99| 19. 01| 234. 7| 4, 50. 10. 55 15.05 29.90| 70. 10 23. 64|425.91
29__ _ _ _ 81. 26|| 18. 74| 230. 6| 4, 51| 10.40|| 14. 91 || 30. 25| 69. 75|| 24. 07|433. 65
30----- 81. 54| 18. 46| 226. 4| 4. 53| 10. 25|| 14. 78. 30. 65. 69. 35 24. 52,441. 70
31_____| 81. 82| 18. 18 222. 2 4 54| 10. 09 14. 63. 31.03 68. 97 24. 98|450. 04
32----- 82. 10, 17. 90 218. 0. 4. 56 9.94| 14. 50 31.45| 68. 55] 25. 46|458. 68
33----- 82. 38 17. 62. 213. 9| 4. 57| 9. 78] 14, 35| 31. 85| 68. 15, 25.96467. 62
34__ _ _ _ 82. 66] 17, 34| 209. 8| 4. 59| 9, 62. 14. 21. 32. 30| 67. 70 26.47|476. 87
35----- 82. 95 17. 05| 205. 5| 4, 60] 9. 46|| 14. 06| 32. 69| 67. 31|| 27. 00|486. 41
36----- 83. 23 16. 77| 201. 5 4, 62. 9. 31|| 13.93| 33. 17| 66. 83| 27. 55|496. 25
37_____| 83. 51| 16. 49| 197. 5| 4, 64. 9. 15| 13. 79| 33. 65 66. 35| 28. 11|506. 40
38----- 83. 79| 16. 21| 193. 5| 4, 65 9. 00. 13. 65|| 34. 07| 65. 93| 28. 69||516. 84
39_____ 84. 07| 15.93| 189. 5 4, 67 8. 84 13. 51| 34. 57 65. 43| 29. 28.527. 58
40_ _ _ _ _ 84. 34 15. 66, 185. 7| 4, 68| 8, 69| 13. 37| 35. 00. 65.00. 29.90|538. 63
41_ _ _ _ _ | 84. 61| 15. 39| 181. 9| 4. 70| 8. 54|| 13. 24| 35. 50 64. 50 30. 53.549. 97
42__ _ _ _ | 84, 89| 15. 11| 178. O| 4, 71 || 8.39|| 13. 10| 35.95| 64. 05, 31. 171561. 62
43----- 85. 15 14.85| 174. 4 4.73| 8. 24 12.97.| 36.47. 63.53. 31.84573. 56
44_ _ _ _ _ ! 85.42 14, 58] 170. 7. 4. 74 8. 09 12. 83| 36.94 63. 06 32. 52 585. 81
Polarimetry, Saccharimetry, and the Sugars
681
TABLE 138.-Solubility of levulose in water—Continued
Basis of computation
Number of molecu- || Mole frac- | Soncentra-
Tem- || Composition | \x, lar weights in 1 kg ti tion of levu-
pera- Water of solution |OIl lose in—
ture to 1
kg.
levu-
r 1 kg 100 g
hº Water lose hº Water| Total hº Water of of
$J water water
Per- | Per- Per- || Per-
oC cent cent g Moles | Moles | Moles | cent cent Moles g
45- - - - - 85. 68. 14. 32| 167. 1 || 4. 76 7. 95 12. 71 || 37. 45 62. 55 33. 21|598. 35
46_____ 85. 94 | 1.4. 06| 163. 6| 4. 77| 7, 80| 12, 57 37. 95| 62. 05| 33. 93|611. 20
47----- 86. 19. 13. 81| 160. 2 4, 78 7.67| 12, 45 38. 39' 61. 61| 34. 66|624. 34
48_____ 86. 45| 13. 55| 156. 7 4. 80. 7. 52' 12. 32| 38.96 61. 04| 35. 40637. 79
49_ _ _ _ _ 86. 69| 13. 31|| 153. 5| 4, 81| 7.39| 12. 20, 39. 43 60. 57| 36. 16651. 53
50----- 86. 94| 13. 06| 150. 2 4, 83| 7. 25| 12. 08' 39. 98 60. 02| 36. 94|665. 58
51----- 87. 18, 12. 82| 1.47. 1, 4, 84| 7. 12; 11.96 40. 47| 59. 53. 37. 74|679. 93
52----- 87. 41 | 12. 59] 144. 0| 4. 85 6. 99| 11. 84| 40. 96, 59. 04; 38. 55694. 57
53----- 87. 65|| 12. 35| 140. 9| 4. 87 6. 86|| 11. 73| 4:1. 52 58. 48 39. 38|709. 52
54----- 87. 88 12. 12| 137. 9| 4, 88 6. 73| 11, 61| 42. 03| 57. 97 40. 23|724. 77
55----- 88. 10| 11. 90 135. 1. 4. 89| 6. 61| 11, 50. 42. 52, 57. 48| 41. 09|740. 32
682 Circular of the National Bureau of Standards
TABLE 139.-Concentration
[Concentrations of Supersaturated solutions of levulose at various percentages of “oversaturation”, et, where
given solution, and cº stands for the weight of levulose required to saturate unit weight of water at temp-
oversaturation at any specified temperature for a given solution is the weight deviation of its dissolved
of Saturation requirement at the specified temperature. In the last column but one, this value is indicated
value is expressed as a percentage of the total weight of levulose in unit weight of water, at whatever
To facilitate intercalculation and interpolation, some of the data are presented in five significant digits.
|
Number of formula weights
9. Tem- Super- Levu. Water to in 1 kg of solution
º perature, Satu- ſº 1 kg of
€ t y t ration *_* V./ levulose
Levu- Water Total
lose t
o C k % g Moles Moles Moles
ſ 20 1. 003 79. 18 262. 9 4. 40 11. 55 15. 95
25 1. 003 80. 41 243. 6 4. 46 10. 87 15. 33
30 1. 003 81. 76 223. 0 4. 54 10. 12 14. 66
35 1. 003 83. 16 202. 5 4. 62 9. 35 13. 97
1. 5
40 1. 002 84. 54 182. 9 4. 69 8. 58 13, 27
45 1. 002 85. 86 164. 7 4. 77 7. 85 12. 62
50 1. 002 87. 11 148. 0 4. 84 7, 16 12. 00
\ 55 1, 002 || 88. 25 133. 1 4. 90 6. 52 11. 42
f 20 1. 006 79. 42 259. 1 4. 41 11. 42 15. 83
25 1. 006 80. 64 240. 0 4. 48 10. 74 15. 22
30 1. 005 81. 98 219. 8 4. 55 10. 00 14. 55
35 1. 005 83. 36 199. 6 4. 63 9. 24 13. 87
3. 0
40 1. 005 84. 73 180. 2 4. 70 8. 48 13. 18
45 1. 004 86. 04 162. 3 4. 78 7. 75 12. 53
50 1. 004 87. 27 145. 9 4. 84 7. 07 11. 91
55 1. 003 88. 41 131. 1 4. 91 6. 44 11. 35
/ 20 1. 009 79. 66 255. 3 4. 42 11. 29 15. 71
25 1. 009 80. 87 236. 6 4. 49 10. 62 15. 11
30 1. 008 82. 19 216. 6 4. 56 9, 88 14. 44
35 1. 007 83. 56 196. 7 4. 64 9. 12 13. 76
4. 5
º 40 1. 007 84. 92 177. 6 4. 71 8. 37 13. 08
. 45 1. 006 86. 21 159. 9 4. 79 7. 65 12. 44
| 50 1. 006 87. 43 143. 8 4. 85 6. 98 11. 83
55 1. 005 88. 55 129. 3 4. 92 6. 35 11, 27
20 1. 012 79. 89 251. 7 4. 43 11. 16 15. 59
25 1. 011 81. 09 233. 2 4. 50 10. 50 15. 00
30 1. 011 82. 40 213. 6 4. 57 9 77 14, 34
35 1. 010 83. 76 194. 0 4. 65 9. O2 13. 67
6. ()
40 1. 009 85. 10 175. 1 4. 72 8. 27 12. 99
45 1. 008 86. 38 157. 7 4. 79 7. 56 12. 35
50 1, 007 87. 59 141. 7 4, 86 6. 89 11. 75
55 1 4 4, 92 6, 27 11, 19
, 007 | 88, 70 127.
Polarimetry, Saccharimetry, and the Sugars
683
data for levulose in water
et=100(c’—c.)/ct, in which c' stands for the weight of levulose dissolved in unit weight of water in the
erature, t, according to the equation cº-0.150103!?–0.814t–H331.023, as listed in table 138.
The index of
levulose contents per unit weight of water, regardless of existing temperature, expressed as a percentage
for the specified temperature of 20° C.; in the last column, headed “y20”, (hypothetical yield at 20°), this
temperature, instead of as a percentage of the weight which would exactly saturate the water at 20° C.
In practical application only the first three or four digits should be used]
Concentration of levulose in—
Over Mole fraction 100 g of water Oversaturation
satu-
ration, 1 kg of Excess at—
6 t ___ ! water
Total
I. - - | O
i. Water t | 20 €20 !/20
% % M g 9 9 % %
ſº º 72. 44 21. 11 || 380. 40 5. 62 5. 62 1. 50 1. 48
29, 11 || 70. 89 22. 79 || 410. 56 6. 07 35. 78 9. 55 8. 71
30. 96 || 69. 04 || 24. 89 448. 33 6. 63 73. 55 19. 62 | 16. 41
* 0. 66. 95 || 24. 40 || 493. 71 7. 30 | 118. 93 31. 73 24. 09
1. 5
35. 35 | 64. 65 30. 35 | 546. 71 8. 08 || 171. 93 45. 87 || 31. 45
37. 79 || 62. 21 || 33. 71 || 607. 33 8. 98 || 232. 55 62. 05 || 38. 29
40. 32 || 59. 68 || 37. 50 | 675. 56 9. 98 || 300. 78 80. 26 || 44. 52
42. 90 || 57. I 0 || 41. 71 || 751. 41 11. 10 || 376, 63 || 100. 49 || 50. 12
27. 85 | 72. 15 21. 43 || 386. 02 11. 24 11. 24 3. 00 2. 91
29. 41 || 70. 59 23. 13 || 416. 62 12. 13 4.1. 84 11. 16 || 10. 04
31. 27 | 68. 73 || 25. 25 || 454. 95 13. 25 80. 17 21. 39 || 17. 62
33. 38 | 66. 62 27. 81 || 501. 00 14. 59 || 126. 22 33. 68 25, 19
3. 0
35. 68 || 64. 32 || 30. 79 || 554. 79 16. 16 | 180. 01 48. 03 || 32.45
38. 13 || 61. 87 || 34, 21 | 616. 30 17. 95 || 241. 52 64. 44 || 39. 19
40. 67 || 59. 33 || 38. 05 | 685. 55 19. 97 || 310. 77 82. 92 || 45. 33
43. 26 || 56. 74 || 42. 33 762. 52 22. 21 || 387. 74 || 103. 46 50. 85
(28. 14 || 71. 86 21. 74 391. 65 16. 87 16. 87 4. 50 4. 31
29, 71 || 70. 29 23. 46 || 422. 69 18. 20 47. 91 12. 78 || 11. 33
& 31. 58 | 68. 42 || 25. 62 461. 58 19. 88 86. 80 23. 16 || 18. 80
33. 70 | 66. 30 28. 21 || 508. 30 2.1. 89 || 133. 52 35, 63 26. 27
4. 5 º
º 63. 98 || 31. 24 || 562. 87 24. 24 | 188. 09 50. 19 || 33. 42
38. 47 61. 53 || 34. 71 || 625. 28 26. 93 250. 50 66. 84 || 40. 06
41. 02 || 58. 98 || 38. 61 | 695. 53 29. 95 || 320. 75 85. 58 46. 12
\43. 62 56. 38 42.94 || 773. 62 33. 31 || 398. 84 || 106. 42 || 51, 56
(28.43 71. 57 22. 05 || 397. 27 22. 49 22. 49 6. 00 5, 66
30. 01 || 69. 99 || 23. 80 || 428. 76 24, 27 53. 98 14. 40 | 12. 59
31. 89 | 68. 11 || 25. 99 || 468. 20 26. 50 93. 42 24. 93 || 19, 95
34. 02 || 65. 98 || 28. 62 515. 59 29. 18 || 140. 81 37. 57 27, 31
6. 0
36. 34 || 63. 66 31, 69 570. 95 32. 32 196. 17 52. 34 || 34, 36
38. 81 61. 19 35. 21 634. 25 35. 90 256. 47 68. 43 | 40, 44
41. 37 58. 63 || 39. 16 || 705. 51 39. 93 || 330. 73 88. 25 || 46, 88
\43. 97 56. 03 || 43. 56 784. 73 44, 42 409. 95 109. 38 52. 24
684
Circular of the National Bureau of Standards
TABLE 139.-Concentration data
Over
Tem- Super-
* perature, satu- º
€t t ration
o C k %
/ 20 1. 015 80. 11
25 1. 014 81. 30
30 1. 013 82. 60
35 1. O12 83. 95
7. 5 K
40 1. 011 85. 27
45 1. 010 86. 55
50 1. 009 87. 74
55 1. 008 88. 84
ſ 20 1. 0.18 80. 33
25 1. 017 81. 51
30 1. 015 82, 80
35 1, 014 84, 13
9. () º
40 1. 013 85. 45
45 1. 012 86. 71
50 1. 011 87. 89
55 1. 010 88, 97
ſ 20 1. 020 80. 55
25 1. 019 81. 72
30 1. 018 83. 00
35 1. 016 84, 31
10. 5 K
40 1. 015 85. 62
45 1. 014 86. 86
50 1, 0.13 88. 03
\ 55 1. 011 89. 11
ſ 20 1. 023 80. 76
25 1. 022 81. 92
30 1. 020 83. 18
35 1. 019 84. 49
12. 0 ||
40 1. 017 85. 78
45 1. 016 87. 02
50 1. 014 88. 17
\ 55 1. 013 89. 24
20 1. 026 80. 97
25 1. 024 82. 11
30 1. 022 83. 37
35 1. 021 84. 66
13. 5 |
40 1. 019 85. 94
45 1. 017 87. 17
50 1. 016 88. 31
\ 55 1. 014 89. 36
Water to
1 kg of
levulose
g
248.
230.
210.
191.
172.
155.
139.
125.
244.
226.
207.
188.
170.
153.
137.
123.
241.
223.
204.
186.
168.
151.
136.
122.
238.
220.
202.
183.
165.
149.
134.
120.
iii
235.
217.
199.
181.
:
163.
147.
132.
119.
:
Number of formula weights
in 1 kg of solution
º Water Total
Moles Moles Moles
4. 45 11. 04 15. 49
4. 51 10. 38 14. 89
4. 58 9. 66 14, 24
4, 66 8. 91 13. 57
4. 73 8, 17 12. 90
4, 80 7. 47 12. 27
4, 87 6. 81 11. 68
4. 93 6. 20 11. 13
4. 46 10. 92 15. 38
4. 52 10. 26 14. 78
4. 60 9. 55 14, 15
4, 67 8. 81 13. 48
4. 74 8. 08 12. 82
4. 81 7. 38 12. 19
4. 88 6. 72 11. 60
4. 94 6. 12 11. 06
4. 47 10. 80 15. 27
4. 54 10, 15 14. 69
4, 61 9. 44 14. 05
4. 68 8. 71 13. 39
4. 75 7. 98 12, 73
4, 82 7. 29 12. 11
4. 89 6. 64 11. 53
4. 95 6. 05 11. 00
4. 48 10. 68 15. 16
4. 55 10. 04 14. 59
4. 62 9. 33 13. 95
4. 69 8. 6] 13. 30
4. 76 7. 89 12. 65
4. 83 7. 21 12. 04
4. 89 6. 57 11. 46
4. 95 5. 97 10. 92
4. 49 10. 56 15. 05
4, 56 9. 93 14. 49
4. 63 9. 23 13. 86
4. 70 8. 51 13. 21
4. 77 7. 80 12. 57
4. 84 7. 12 11. 96
4. 90 6. 49 11. 39
4. 96 5. 90 10. 86
Polarimetry, Saccharimetry, and the Sugars
for levulose in water—Continued
Mole fraction
Concentration of levulose in—
100 g of water
Oversaturation
Over
satu-
ratiºn, 1 kg of Excess at-
2 : Water
Total
"... water t 20° €20 $/20
% % M g Q % %
28. 72 71. 28 22. 36 | 402. 89 28. 11 || 28. 11 7. 50 6, 98
30. 3] 69. 69 24. 14 || 434. 83 30. 34 60. 05 | 16. 02 13. 81
32. 20 67. 80 26. 36 474. 83 33. 13 | 100. 05 || 26. 69 21. 07
7. 5 34. 34 || 65. 66 29. 02 522. 89 36. 48 148. 11 || 39. 52 28. 33
• *)
law ºf 63. 33 32. 14 || 579. 03 | 40. 40 204. 25 54. 50 | 35. 27
39. 14 60. 86 35. 70 643. 23 44. 88 268. 45 71. 63 41. 73
41. 71 || 58. 29 39. 72 715. 50 49. 92 || 340. 72 90. 91 47. 62
(44. 32 55.68 44. 17 | 795. 83 55. 52 || 421.05 || 112. 35 52.91
29. 00 | 71. 00 22. 68 || 408. 51 || 33. 73 || 33. 73 9. ()0 | 8. 26
30. 60 69.40 24.47 440. 89 36.40 | 66. 11 17.64 14.99
32. 50 | 67. 50 || 26. 72 481. 45 39. 75 106. 67 || 28. 46 22, 16
34, 65 65. 35 | 29. 43 530. 19 || 43. 78 155. 41 || 41. 47 29, 31
9. ()
law on 63. 01 || 32. 59 || 587. 11 || 48. 48 212. 33 56. 65 || 36. 1 7
39. 48 60. 52 || 36. 20 || 652. 20 53, 85 277. 42 74. 02 || 42. 54
42. 05 57.95 | 40. 27 | 725. 48 59.90 350, 70 | 93. 57 || 48. 34
(44.66 55. 34 44. 79 || 806. 94 66.63 || 432. 16 115. 31 || 53. 56
(29. 29 || 70. 71 || 22. 99 || 414, 13 || 39. 35 | 39. 35 | 10. 50 9. 50
30, 89 69. 11 24, 81 446. 96 || 42. 47 | 72. 18 19. 26 16. 15
32.80 67. 20 27.09 488. 08 46.38 113. 30 30. 23 23, 21
34.96 65.04 29. 83 537.48 51.07 162. 70 43.41 30, 27
10. 5 !
is a 62. 69 33. 04 || 595. 19 56. 56 220. 41 58. 81 37. 03
||39.80 60. 20 | 36.70 | 661. 18 62.83 286. 40 76.42 43. 32
42. 38 57. 62 | 40. 82 | 735. 47 | 69. 89 || 360. 69 96. 24 || 49. 04
(45. 00 55.00 || 45. 41 || 818. 04 || 77. 73 || 443. 26 118. 27 | 54. 19
29. 57 70. 43 || 23. 30 419. 75 44. 97 44. 97 12.00 10. 71
|31. 18 68.82 25, 15 453. 03 || 48.54 78.25 20.88 17, 27
|| 33. 10 | 66. 90 27. 46 494. 70 53. 00 || 1 19. 92 || 32. 00 24. 24
* * 64. 73 || 30, 24 544. 78 58. 37 170. 00 || 45. 36 31. 21
12. 0
37. 63 || 62. 37 || 33. 49 || 603, 27 | 64, 64 228. 54 60. 98 || 37. 88
40. 13 59. 87 || 37. 20 | 670. 15 71. 80 295. 37 78. 81 44. 08
42. 71 || 57. 29 || 41. 38 745. 45 79. 87 370. 67 98.90 || 49. 72
(45.33 54.67 46.02 829, 15 88.84 454, 37 121. 24 54.80
(29, 84 70. 16 23. 61 425, 38 50 60 50 60 13. 50 11.90
|| 31.47 | 68. 53 25. 48 459. 10 54.61 84.32 22. 50 | 18. 37
|| 33. 39 | 66. 61 27. 83 501, 33 59. 63 126. 55 33. 77 || 25. 24
|* * 64. 43 || 30. 64 552. 08 65. 67 117. 30 47. 31 32. 1 1
13. 5
37. 94 | 62. 06 || 33.93 611. 35 | 72. 72 236. 57 63. 12 38. 70
40. 45 59. 55 37.70 | 679. 13 80. 78 304. 35 81. 21 44, 81
|43. 03 56.97 || 41.93 755. 43 | 89. 85 380. 65 | 101.57 50, 39
| \45. 66 54, 34 46. 64 840. 25 99.94 465. 47 124. 20 55. 40
323414°—42—45
686
Circular of the National Bureau of Standards
TABLE 139.- Concentration data
Over
Satu-
ration,
€;
15. 0
16. 5
18. 0
19. 5
Number of formula weights
in 1 kg of solution
Tem- Super- | Levu- Water to
perature, Satu- lose 1 kg of
t ration levulose
lº Water Total
o C k % g Moles Moles Moles
20 1. 028 81. 17 232. 0 4. 51 10. 45 14. 96
25 1. 027 82. 31 215. 0 4. 57 9, 82 14, 39
30 1. 025 83. 55 196. 9 4. 64 9. 13 13. 77
35 1. 023 84. 83 178. 8 4. 71 8, 42 13, 13
40 1. 021 86. 10 161. 4 4. 78 7. 72 12. 50
45 1. 019 87. 31 145. 3 4. 85 7. 04 11. 89
50 1. 017 88. 44 130. 6 4. 91 6. 41 11. 32
55 1. 016 89. 49 117. 5 4. 97 5. 83 10. 80
20 1. 031 81. 36 229. 0 4. 52 10. 34 14, 86
25 1. 029 82. 49 212. 2 4. 58 9. 72 14. 30
30 1. 027 83. 73 194. 3 4. 65 9. 03 13. 68
35 1. 025 85. 00 176. 5 4. 72 8. 33 13. 05
K
40 1. 023 86. 25 159. 4 4. 79 7. 63 12. 42
45 1. 021 87. 4.5 143. 5 4. 85 6. 97 11. 82
50 1. 019 88. 58 129. 0 4. 92 6. 34 11. 26
55 1. 017 89. 61 115. 9 4. 97 5. 77 10. 74
20 1. 033 81. 56 226. 1 4. 53 10. 24 14. 77
25 1. 031 82. 68 209. 5 4. 59 9. 61 14. 20
30 1. 029 83. 90 191. 9 4. 66 8. 94 13. 60
35 1. 027 85. 16 174. 2 4. 73 8. 24 12. 97
40 1. 025 86. 41 157. 3 4. 80 7. 55 12. 35
45 1. 022 87. 59 141. 6 4. 86 6. 89 11. 75
50 1. 020 88. 71 127. 3 4. 92 6. 27 11. 19
55 1. 018 89. 73 114. 5 4. 98 5. 70 10. 68
ſ 20 1. 036 81. 75 223. 3 4. 54 10. 13 14. 67
25 1. 033 82. 86 206. 9 4. 60 9. 51 14. 11
30 1. 031 84. 07 189. 5 4, 67 8. 84 13. 51
35 1. 029 85. 32 172. 0 4. 74 8. 15 12. 89
| 40 1. 026 86. 55 155. 4 4. 80 7. 47 12. 27
45 1. 024 87. 73 139, 9 4. 87 6. 81 11. 68
50 1. 022 88. 83 125. 7 4. 93 6. 20 11. 13
\ 55 1. 020 89. 84 113. 0 4. 99 5. 64 10. 63
ſ 20 1. 038 81. 93 220. 5 4. 55 10. 03 14. 58
25 1. 036 83. 03 204, 3 4. 61 9. 42 14. 03
30 1. 033 84. 24 187. 1 4. 68 8. 75 13. 43
35 1. 031 85. 48 169. 9 4. 74 8. 06 12. 80
40 1. 028 86. 70 153. 4 4. 81 7. 38 12. 19
45 1. 025 87. 86 138. 1 4. 88 6. 74 11. 62
50 1. 023 88. 95 124, 2 4. 94 6. 13 11. 07
55 1. 021 89. 96 111. 6 4. 99 5. 57 10. 56
Polarimetry, Saccharimetry, and the Sugars
687
for levulose in water—Continued
|
ſ
|
Concentration of levulose in—
Over Mole fraction 100 g of water Oversaturation
satu-
ratiºn. 1 kg of Excess at—
2 water
Total
ſº Water t 20° 620 !/20
% % M Q g g % %
(30. 12 || 69. 88 23. 92 || 431. 00 56. 22 56. 22 15. 00 || 13. 04
31, 75 | 68. 25 || 25. 82 || 465. 16 60. 67 90. 38 24. 12 | 19. 43
33. 69 | 66. 31 || 28, 20 507. 96 66. 26 || 133. 18 35. 53 || 26. 22
as sº 64. 13 || 31. 05 559. 37 72, 96 || 184. 59 49. 25 | 33. 00
15. 0
38. 25 | 61. 75 || 34. 3 619. 42 80. 79 244. 64 65. 28 39. 50
40. 76 59. 24 || 38. 19 | 688. 10 89, 75 313. 32 83. 60 45. 53
43. 36 56. 64 42. 49 || 765. 42 99. 84 || 390. 64 || 104. 23 || 51. 04
\45. 99 || 54.01 || 47. 26 || 851. 36 || 111. 05 || 476. 58 127. 16 55.98
(30. 39 || 69. 61 24. 24 || 436. 62 61. 84 61. 84 16. 50 || 14. 16
32. 03 67. 97 26. 16 || 471. 23 66. 74 96.45 25. 74 20. 47
33. 98 || 66. 02 || 28. 56 || 514, 58 72. 88 || 139. 80 37. 30 27. 17
36. 17 | 63. 83 || 31. 45 566. 67 80. 26 || 19.1. 89 51. 20 || 33.86
16. 5
38. 56 || 61. 44 || 34. 83 627. 50 88. 87 252. 72 67. 43 | 40. 27
41. 08 || 58. 92 || 38. 69 || 697. 08 98. 73 || 322. 30 86. 00 || 46. 24
43. 68 56. 32 || 43. 04 || 775. 40 | 109. 82 | 400. 62 106. 89 || 51. 67
\46. 31 || 53. 69 47.87 862. 46 | 121. 15 || 487. 68 || 130. 12 56. 55
30. 66 69. 34 24. 55 442. 24 67. 46 67. 46 18. 00 15. 25
32. 31 || 67. 69 || 26. 49 || 477. 30 72. 81 || 102. 52 27. 35 | 21. 48
34. 26 || 65. 74 || 28. 93 || 521. 21 79. 51 | 1.46. 43 39. 07 28. 09
36. 47 63. 53 || 31. 86 573. 96 87. 55 | 199. 18 53. 15 || 34. 70
18. 0
38. 86 6.1. 14 || 35. 28 635. 58 96. 95 260. 80 69. 59 || 41. 03
41. 39 58. 61 || 39. 19 || 706. 05 || 107. 70 || 331. 27 88. 39 || 46. 92
43. 99 || 56. 01 || 43. 59 || 785. 38 119. 80 || 410. 60 | 109. 56 52. 28
\46. 63 53. 37 || 48. 49 873. 57 133. 26 || 498. 79 || 133. 09 || 57. 10
(; º; 69. 07 || 24. 86 || 447. 86 73. 08 73. 08 19. 50 | 16. 32
32. 59 || 67. 41 || 26. 83 || 483. 37 78. 88 || 108. 59 28. 97 22, 46
34. 55 || 65. 45 29. 30 527. 83 86. 13 153. 05 40. 84 || 29. 00
* * 63. 24 || 32. 26 || 581. 26 94. 85 | 206. 48 55. 09 || 35. 53
19. 5
39. 16 || 60. 84 || 35. 73 || 643. 66 || 105. 03 || 268. 88 71. 75 41. 77
41. 69 58. 31 || 39. 69 || 715. 03 || 116. 68 || 340. 25 90. 79 47. 59
44, 30 55. 70 || 44, 15 795. 37 | 129. 79 || 420. 59 | 112. 22 || 52. 88
\46. 94 53. 06 || 49. 11 | 884. 67 || 144. 36 509, 89 136. 05 57.64
(31. 20 | 68. 80 25. 17 453. 48 78. 70 78. 70 21. 00 17. 35
32, 86 || 67. 14 27, 17 || 489. 43 84. 94 | 114. 65 30. 59 || 23. 43
34, 83 || 65. 17 | 29. 67 || 534. 46 92. 76 159. 68 4.2. 61 29, 88
37. 05 || 62. 95 || 32. 67 588. 56 102. 15 213. 78 57. 04 || 26. 32
21. ()
39. 46 60. 54 || 36. 18 651. 74 || 1 13, 11 276. 96 73. 90 42. 50
42. 00 58. 00 | 40. 19 || 724. 00 | 125. 65 || 349. 22 93. 18 || 48. 24
44. 61 55. 39 44. 70 805. 35 | 139. 77 430. 57 114.89 53. 46
47. 25 52, 75 49, 72 | 895. 78 155, 47 521.00 || 139.01 58. 16
688
Circular of the National Bureau of Standards
TABLE 139.- Concentration data
Over
satu-
ration,
6,
22. 5
24. ()
|
Number of formula weights l
Tem- Super- Levu- Water to in 1 kg of solution
perature, satu- i. 1 kg of
t ration Se levulose
hº Water Total
OSé
o C k % g Moles Moles Moles
ſ 20 1. 040 82. 11 217. 8 4. 56 9. 93 14. 49
25 | 1. 038 || 83. 21 201. 8 4, 62 9. 32 13. 94
30 1. 035 84. 40 184. 8 4, 68 8. 66 13. 34
35 1. 032 85. 63 167. 8 4. 75 7. 98 12. 73
( |
40 1. 030 86. 84 151. 6 4. 82 7. 30 12. 12
45 1. 027 87. 99 136. 4 4, 88 6. 66 11. 54
50 1. 025 89. 08 122. 6 4. 94 6. 06 11. 00
\ 55 I. 022 90. 07 I 10. 3 5. 00 5. 51 10. 51
ſ 20 1. 042 82. 29 215. 2 4. 57 9. 83 14. 40
25 1. 040 83. 38 199. 4 4, 63 9. 23 13. 86
30 1. 037 84. 56 182. 6 4, 69 8. 57 13. 26
35 1. 034 85. 78 165. 8 4. 76 7. 89 12. 65
| 40 1. 03] 86. 98 | 49. 7 4. 83 7. 23 12. 06
45 1. 028 88. 12 134. 8 4, 89 6. 59 11. 48
50 1. 026 89. 19 121. 2 4. 95 6. 00 10. 95
\ 55 1. 023 90. 18 108. 9 5. 01 5. 45 10. 46
Polarimetry, Saccharimetry, and the Sugars
689
for levulose in water—Continued
Concentration of levulose in—
Over Mole fraction | 100 g of water Oversaturation
satu-
ratiºn, 1 kg of Excess at-
5 Water
Total --
º Water t 200 620 !/20
O % M g g 9 % %
(31. 47 | 68. 53 25. 48 || 459. 11 84. 33 84. 33 22. 50 | 18. 37
33. 13 | 66. 87 | 27. 50 495. 50 91. 01 || 120. 72 32. 21 24, 36
35. 11 | 64, 89 30. 03 || 541. 08 99. 38 166. 30 44. 37 || 30. 74
37. 34 || 62. 66 || 33. 07 || 595. 85 109. 44 221. 07 58. 99 || 37. 10
22. 5
39. 75 60. 25 || 36. 62 || 659. 82 | 121. 19 285. 04 76. 06 || 43. 20
42. 30 || 57. 70 | 40. 69 | 732. 98 || 134. 63 || 358. 20 95. 58 || 48. 87
º 91 || 55. 09 || 45. 26 815. 34 || 149. 76 || 440. 56 || 117. 55 54. 03
47. 56 || 52. 44 50. 34 || 906. 88 | 166. 57 || 532. 10 || 141. 98 || 58. 67
É 73 | 68. 27 || 25. 80 || 464. 73 89, 95 89. 95 24. 00 | 19. 36
33. 40 | 66. 60 27. 84 || 501, 57 97. 08 || 126. 79 33. 83 || 25. 58
35. 39 64. 61 || 30, 40 || 547. 71 || 106. 01 || 172. 93 46. 14 || 31. 57
37. 62 62. 38 || 33. 48 || 603. 15 || 116. 74 228. 37 60. 93 37. 86
24. 0
40. 05 || 59. 95 || 37. 07 | 667. 90 | 129. 27 | 293. 12 78. 21 || 43. 89
42. 59 || 57. 41 || 41. 18 || 741. 95 || 143. 60 | 367. 17 97.97 || 49. 49
45. 22 54. 78 || 45. 81 | 825. 32 | 159. 74 || 450. 54 | 120. 21 54. 59
\47. 86 52. 14 50. 95 || 917. 98 || 177. 67 543. 20 | 1.44. 94 || 59, 17
690 Circular of the National Bureau of Standards
TABLE 140.-Solubility of lactose in water
[The respective solid phases are in equilibrium with their saturated solutions in
which the mutarotation is complete]

Lactose in
Temperature saturated Observer b
solution a
SOLID PHASE, oſ-LACTOSE HYDRATE
o C Percent
0 10. 6 H
15 14. 4 H
21. 5 16. 7 S
25 17. 8 H
28 19. 4 S
38 23. 5 S
39 24. 0 H
48 c 29. 6 S
49 29. 7 H
57. 0 c 35. 9 S
57. 1 34. 9 G
63. 9 39. 1 G
64. 0 39. 7 H
65. 0 c 43. 5 S
73. 5 45. 8 G
74. 0 46. 2 H
79. 1 49. 6 G
87. 2 55. 1 G
88. 2 56. 0 G
89. 0 c 58. 1 H
SOLID PHASE, 3–LACTOSE (ANHYDROUS)
100. 0 60. 7 H
107. 0 63. 9 G
121. 5 69. 4 G
133. 6 73. 2 G
138. 8 75. 2 G
158. 8 81. 1 G
178. 8 86. 7 G
* Referred to anhydrous lactose.
b H = C. S. Hudson; S=E. Saillard; G =J. Gillis.
c These temperatures deviated somewhat from a plotted curve.
Polarimetry, Saccharimetry, and the Sugars
691
TABLE 141.-Approximate composition of invert-sugar solutions saturated with
respect to deactrose at various temperatures (computed)
Composition of
º invert sugar Invert sugar
Tempera- Des: Se IIl solutions to 100 g of
ture W8,062F saturated water
with dextrose
oC Percent Percent g
0 35. 0 50. 8 103. 3
10. 0 40. 8 56. 6 130. 4
15. 0 44. 0 59. 8 148. 7
20. 0 47. 2 62. 6 167. 4
25. 0 50. 80 66. 2 195. 8
30. 0 54. 64 69. 7 230. 0
35. 0 58. 02 72. 2 259. 7
40. 0 61. 87 74. 8 296. 8
45. 0 65. 71 78. 0 354. 5
50. 0 70. 91 81. 9 452. 5
TABLE 142. – The system: Deatrose, levulose, and water, at 30° C, with hydrated
deactrose as the solid phase

Dextrose | Levulose Dextrose | Levulose Total
by by d 39 to 100 g of to 100 g of O
weight weight water water Sugar
Percent | Percent g g Percent
54. 64 0.00 |_ _ _ _ _ _ _ _ _ _ 120. 46 0 54. 64
49. 34 8. 94 1. 2639 118. 26 21. 43 58. 28
49. 32 8. 94 1. 2650 118. 16 21. 42 58. 26
45. 97 14. 50 1. 2779 116. 27 36. 68 60. 47
41. 01 23. 23 1. 3000 114. 68 64. 96 64. 24
35. 76 33. 09 1. 3286 114. 83. 106. 23 68. 85
34. 48 35. 69 1. 3359 115. 59 119. 23 70. 17
33. 67 37. 10 1. 3408 115. 19 126. 92 70. 77
32. 55 39. 39 1. 3480 116. 00 140. 38 71. 94
692
Circular of the National Bureau of Standards
|All solutions are saturated with respect to sucrose]
Sucrose in 100 g of water at—
Invert sugar
to 100 g of
Water 23.15° C 30° C 50° C
g g g g
0 208. 6 213. 6 260. 4
20 198. 8 206. 7 252. 1
40 190. 8 200. 1 245. 0
80 177. 2 188. 1 233. 2
160 156. 0 167. 3 213. 9
200 |_ _ _ _ _ _ _ _ _ _ _ _ _ 159. 3 207. 9
300 - - - - - - - - - - - - - 147. 3 196. 0
400 - … m. - ~ * = --- - - - -- a-- 140. 4 188. 5
TABLE 143.- Influence of invert sugar on the solubility of sucrose
TABLE 144.— Composition of solutions of macimum solubility at various
temperatures (computed)
T I t Sucrose º: º ..º.
emper- * † & Y - 1 In Ver a + or sugar UO | Sugar UO alone UO
ature Sucrose Sugar Water º lſº g 100 g of 100 g of 100 g of
OI W3, LCI' water water water
oC % % % g Q g g
0 43. 7 27. 2 29. 1 150. 2 93. 5 243. 7 179. 2
1() 40. 9 31. 8 27. 3 149. 8 116. 5 266. 3 190. 5
15 39. 1 34, 8 26. 1 149. 8 133. 4 283. 2 197. ()
23, 15 36. 3 39, 9 23. 8 152. 5 167. 6 319. 1 208. 5
30 33. 6 45. 4 21. 0 160. () 216. 2 376. 2 213. 6
40 31. 1 50. 7 18. 2 170. 9 278. 6 449. 5 238. 1
50 27, 7 58. 0 14. 3 193. 7 405. 6 599. 3 260. 4
Polarimetry, Saccharimetry, and the Sugars
693
ADDITIONAL LITERATURE REFERENCES TO A CCOMPANY TABLES INDICATED
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
. Z. Ver. Rübenzucker-Ind. 32 (N. F. 19) 606, 865 (1882).
. J. Am. Chem. Soc. 43, 1522 (1921).
. Bul. Soc. Chim. 35, 1285 (1906).
. Z. Ver. Rübenzucker-Ind. 35 (N. F. 22), 1002 (1885).
. Z. Zuckerind. Čechoslovak. Rep. 58, 1 (1933).
. J. Soc. Chem. Ind. 42, 33T (1923).
. J. Soc. Chem, Ind. 42, 34T (1923).
. J. Soc. Chem. Ind. 50, 86T (1931).
. J. Soc. Chem. Ind. 46,435T (1927).
. BS J. Research 8, 439 (1932) RP426.
. Ind. Fing. Chem., Anal. Ed. 6, 354 (1934)
. Ind. Eng. Chem., Anal. Ed. 6, 354 (1934).
. Ind. Eng. Chem., Anal. Ed. 10, 246 (1938).
. BS J. Research 8, 440 (1932) R P426.
. BS J. Research 8, 444 (1932) R P426.
. BS J. Research 8, 442 (1932) R P426.
. Int. Sugar J. 39, 15s (1937).
. Int. Sugar J. 39, 15s (1937).
. Biochem. Z. 135, 46 (1923).
. Int. Sugar J. 34, 213 (1932).
Table 102.
Table 103.
Table 104.
Table 105.
Table 106.
Table 107.
Table 109.
Table 111.
Table 112.
Table 117.
Table 119.
Table 120.
Table 124.
Table 126.
Table 127.
Table 128.
Table 134.
Table 137.
Table 140.
Table 141.
Table 143.
Table 144.
Z. anal. Chem. 107, 328 (1936)
Biochem. Z. 81, 263 (1917).
Spiritusind. 56, 64 (1933).
Methods of Analysis of the Assoc. Official Agr. Chem., 5th ed., p. 686,
BS Circular C19, p. 52 (1924).
BS Circular C19, p. 52 (1924).
F. J. Bates and H. W. Bearce, Tech. Pap. BS 11 (1918) T115.
NBS Circular C295 (1926).
F. J. Bates and H. W. Bearce, Tech Pap. BS 11 (1918) T 115.
BS Circular C375 (1929).
BS Circular C375, p. 5 (1929).
R. F. Jackson and J. A. Mathews, BS J. Research 8, 437 (1932) RP426.
Int. Sugar J. 39, 23S (1937).
O. Schönrock, Z. Ver. deut. Zucker-Ind. 61, 425 (1911).
Methods of Analysis, Assoc. Official Agr. Chem., 5th ed., 670, (1940).
R. F. Jackson and J. A. Mathews, BS J. Research 8, 438, (1932) RP 426.
Z. Ver. deut. Zucker-Ind. 42, 181 (1892).
BS Sci. Pap. 17, 721 (1922) S437.
Rec. trav, chim. 39, 677 (1920).
Tech. Pap. BS 18, 291 (1924) T259.
Tech. Pap. BS 18, 289 (1924) T259.
Tech. Pap. BS 18, 289 (1924) T259.
(1940).
694
Circular of the National Bureau of Standards
TABLE 145.-Elevation of the boiling point * of sucrose solutions above that of water
at various pressures
Solids
per 100
g. of
water
Brix
Vapor pressure, pounds per square inch
2.8886 3.6269 4.51.93
5.5908 6.8688 8.3837 I (). 168
Vapor pressure, millimeters of mercury
149.38 187.56 233.71 289.13 |sº 433.56 525.84
Boiling point of water, degrees centigrade
60 65 70 75 80 85 90
Elevation, degrees centigrade, above the boiling point of water
100-PERCENT PURITY
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
1,000
1,050
1,100
1,150
1,200
1,250
1,300
1,350
1,400
1,450
1,500
1,550
1,600
0. 58
1. 41
2. 35
3. 36
4. 40
5
6
61
46
44
48
56
i
2
2
• To find the boiling point of a solution of sugar and water, add the boiling point elevation to the boil-
ing point of water at the top of the column.
Polarimetry, Saccharimetry, and the Sugars 695
TABLE 145.—Elevation of the boiling point" of sucrose solutions above that of water
at various vapor pressures—Continued
Vapor pressure, pounds per square inch
12.260 14.696 17.520 20.779 24.519 |sº 33.661 39.177
Vapor pressure, millimeters of mercury
Solids
per 100 634.02 || 760.00 906.04 || 1074.58 1267.99 ||1489.12|1740.77|2026.03
g. Of
Water
Boiling point of water, degrees centigrade
95 100 105 110 115 120 125 130
Elevation, degrees centigrade, above the boiling point of water
100-PERCENT PluRITY
g
50 (). 72 0. 74 0. 76 0. 79 0. 82 0. 84 0. 87 0. 90
100 1, 73 1. 79 1. 85 1. 91 1. 97 2. 04 2. 10 2. 17
150 2. 88 2. 98 3. 08 3. 18 3. 28 3. 39 3. 50 3. 61
200 4. 11 4. 25 4. 39 4. 53 4. 68 4. 83 4. 99 5. 15
250 5. 39 5. 57 5. 75 5. 94 6. 14 6. 34 6. 54 6. 75
300 6. 66 6. 88 7. 11 7. 34 7. 58 7. 83 8. 08 8. 34
350 7. 92 8. 18 8. 45 8. 73 9. 01 9. 30 9. 60 9. 91
400 9. 14 9. 44 9. 75 10. 07 10. 40 | 10. 74 || 1 1. 08 11. 44
450 10. 31 10. 65 11. 00 11. 36 11. 73 | 12. 11 | 12. 50 12. 90
500 |_ _ _ _ _ _ _ _ 11. 81 12. 20 12. 60 13. 01 || 13. 43 || 13. 87 14. 31
550 |_ _ _ _ _ _ _ _ 12. 93 13. 36 13. 80 14. 25 | 1.4. 71 | 15. 18 15. 67
600 |_ _ _ _ _ _ _ _ 13. 98 14. 44 14. 92 15. 40 | 15. 90 | 16. 42 16. 94
650 |_ _ _ _ _ _ _ _ 14. 98 15. 47 15. 98 16. 50 | 17. 04 || 17. 59 18. 15
700 |_ _ _ _ _ _ _ _ 15. 93 16. 46 17. 00 17. 55 | 18. 12 | 18. 71 || - - - - - - -
750 |_ _ _ _ _ _ _ _ 16. 84 17. 40 17. 97 18. 55 | 19. 16 | 19. 77 |
800 |_ _ _ _ _ _ _ _ 17. 69 18. 27 18, 88 19. 49 20. 12 20. 77 |_ _ _ _ _ _ _
850 |_ _ _ _ _ _ _ _ 18. 51 19. 12 19. 75 20. 39 21. 06 || 21. 73 ||
900 |- - - - - - - 19. 27 19. 91 20. 56 21. 23 21. 92 22. 63
950 |_ _ _ _ _ _ _ _ 20. 01 20. 67 21. 35 22. 05 22. 76 || 23. 50 |
1,000 |_ _ _ _ _ _ _ _ 20. 70 21. 38 22. 09 22. 81 || 23. 55 | 24, 31 |_ _ _ _ _ _ _
1,050 |_ _ _ _ _ _ _ _ 21. 36 22. 06 22, 79 23. 53 24, 30 || 25. 08 |_ _ _ _ _ _ _
1,100 |_ _ _ _ _ _ _ _ 21. 99 22. 72 23. 46 24. 23 25. 01 25. 82 | – - - - - - -
1, 150 |- - - - - - - - 22. 58 23. 33 24. 09 24. 88 25. 68 26. 51 || - - - - - -
1,200 |_ _ _ _ _ _ _ _ 23. 16 23. 92 24. 71 25. 52 26. 34 27. 19 |_ _ _ _ _ _ _
1,250 |_ _ _ _ _ _ _ _ 23. 70 24. 48 25. 29 26. 11 || 26. 96 || 27. 83 ||
1,300 |_ _ _ _ _ _ _ _ 24, 22 25. 02 25. 84 26. 69 27. 55 28. 44 |_ _ _ _ _ _ _
1,350 |_ _ _ _ _ _ _ _ 24. 71 25. 53 26, 37 27. 23 28. 11 || 29. 01 || – - - -
1,400 - - - - - - - - 25. 18 26. 01 26. 87 27. 74 || 28. 64 || 29. 57 |_ _ _ _ _ _ _
1,450 |_ _ _ _ _ _ _ _ 25. 64 26. 49 27, 36 28. 25 | 29, 17 || 30. 11 |_ _ _ _ _ _ _
1,500 |_ _ _ _ _ _ _ _ 26. 07 26. 93 27. 82 28. 72 29. 65 || 30. 61 |_ _ _ _ _ _ _
1,550 - - - - - - - - 26. 49 27, 36 28, 26 29. 19 || 30. 13 || 31. 10 || - - - - - -
1,600 |_ _ _ _ _ _ _ _ 26. 88 27.77 28. 68 29. 62 30. 58 || 3:1. 56 || - - - - -
Erample.—Required: the boiling point, under a pressure of 4.5 lb./in.2 of a 92 Brix, 90 purity, sucrose
solution. Boiling point=70°–H19.58°=89.58° C.
696
Circular of the National Bureau of Standards
TABLE 145.-Elevation of the boiling point" of sucrose solutions above that of water
Continued
Vapor pressure, pounds per square inch
2.8886 3.6269 4.51.93 5.5908 6.8688 8.3837 || 10.168
Vapor pressure, millimeters of mercury
Solids -------
per 100 Brix
g. of 149.38 187.56 || 233.71 289. 13 || 355.22 || 433.56 || 525.84
water
Boiling point of water, degrees centigrade
60 65 70 75 80 85 90
Elevation, degrees centigrade, above the boiling point of water
90-PERCENT PURITY b
50 33. 33 0. 66 0. 68 0. 70 0. 73 0. 75 0. 78 (). 80
100 50, 00 1. 61 1. 67 1. 73 1. 79 1. 85 1. 91 1. 97
150 60. 00 2. 64 2. 73 2. 83 2. 93 3. 03 3. 13 3. 24
200 66. 67 3. 70 3. 83 3. 97 4. 11 4. 25 4. 39 4. 54
250 71. 43 4. 78 4. 95 5. 12 5. 30 5. 48 5. 67 5. 85
300 || 75. 00 5. 84 6. 04 6. 26 6. 47 | 6, 70 6. 93 7. 16
350 77. 78 6. 88 7. 13 7. 38 7. 63 7. 90 8. 17 8. 44
400 80. 00 7, 88 8, 16 8. 45 8. 74 9. 05 9. 35 9. 66
450 8.1. 82 8. 85 9, 17 9. 49 9, 82 | 10. 16 || 10. 50 10. 85
500 83. 33 9. 77 10, 12 10. 48 10. 84 || 1 1. 22 || 11. 60 11. 99
550 84. 62 10. 65 11. 03 11. 42 11. 82 | 12. 22 | 12, 64. 13. 07
600 || 85. 71 11. 49 11, 90 12. 32 12. 75 13. 19 || 13. 64 14. 10
650 86. 67 |_ _ _ _ _ _ _ _ 12. 71 13. 16 13. 62 14. 09 || 14. 57 15. 07
700 87. 50 |_ _ _ _ _ _ _ _ 13. 49 13. 97 14. 46 14. 96 15. 47 15. 99
750 88. 24 |_ _ _ _ _ _ _ _ 14, 23 14. 73 15. 24 || 15. 77 | 16, 31 16. 86
800 88. 89 |_ _ _ _ _ _ _ _ 14, 93 15. 46 16. 00 | 16. 55 17. 12 17. 70
850 89.47 |_ _ _ _ _ _ _ _ 15. 60 16. 15 16. 71 || 17. 29 || 17, 88 18. 49
900 90. 00 16, 22 16. 79 17. 38 || 17. 98 || 18. 59 19. 22
950 90. 48 || - - - - - 16, 82 17. 4.1 18, 02 | 18. 64 | 19, 28 19. 93
1,000 90. 91 || - - - - - - - 17, 38 17. 99 18. 62 | 19, 27 | 19. 92 20. 60
1,050 91. 30 |_ _ _ _ _ _ 17. 92 18. 55 19, 20 | 19. 86 20. 54 21. 24
1,100 91. 67 |_ _ _ _ _ _ _ _ 18, 43 19. 08 19, 75 | 20. 43 || 21. 13 21. 84
1,150 92. 00 |_ _ _ _ _ _ _ _ 18, 9.1 19, 58 20. 26 20. 96 || 21. 68 22. 42
1,200 92. 31 || - - - - - - - 19. 39 20. 07 20. 77 21. 49 22, 22 22. 98
1,250 92. 59 |_ _ _ _ _ _ _ _ 19, 82 20, 52 21. 24 21. 97 22. 72 23. 50
1,300 92. 86 |_ _ _ _ _ _ _ _ 20. 25 20. 96 21. 69 22, 44 || 23, 21 24. 00
1,350 93. 10 |_ _ _ _ _ _ _ _ 20. 65 21. 38 22. 12 22. 89 || 23. 67 24. 47
1,400 93. 33 |- - - - - - - - 21. 04 21. 78 22. 54 || 23. 32 24. 12 24. 93
1,450 93. 55 |_ _ _ _ _ _ _ _ 21. 40 22. 16 22. 93 23. 72 | 24. 53 25. 36
1,500 93. 75 |_ _ _ _ _ _ _ _ 21. 76 22. 52 23. 31 24, 12 24. 94 25. 79
1,550 93. 94 | 22. 10 22, 88 23. 67 || 24. 49 || 25. 33 26. 19
1,600 94. 12 |_ _ _ _ _ _ _ _ 22. 43 23. 22 24. 03 || 24, 86 25. 71 26. 58
a See footnote a, p. 694–5. * &
b Values given in the table for impure solutions are based on determinations made on product in which the
impurity was beet molasses.
Polarimetry, Saccharimetry, and the Sugars 697
Elevation of the boiling point % of sucrose solutions above that of water
at various vapor pressures–Continued
TABLE 145.
Vapor pressure, pounds per square inch
12.260 14.696 || 17.520 20.779 24,519 28.795 || 33.661 39.177
Vapor pressure, millimeters of mercury
Solids hº
per 100 634.02 || 760.00 906.04 || 1074.58 1267.99 ||1489.12|1740.77|2026.03
g. Of
Water
Boiling point of water, degrees centigrade
95 100 105 110 115 120 125 130
Elevation, degrees centigrade, above the boiling point of water
90-PERCENT PURITY b
50 0. S3 0. 86 0. 89 (). 92 (). 95 0. 98 1. 01 1. 04
10 2. 04 2. 11 2. 18 2. 25 2. 32 2. 40 2. 48 2. 56
150 3. 35 3. 46 3. 57 3. 69 3. 81 3. 94 4. 06 4. 19
200 4. 69 4. 85 5. 01 5. 17 5. 34 5. 52 5. 69 5. 88
250 6. 06 6. 26 6. 47 6. 68 6. 90 7, 12 7. 35 7. 59
300 7. 40 7. 65 7. 90 8, 16 8. 43 8. 70 8. 98 9. 27
350 8. 73 9. 02 9. 32 9, 62 9. 94 || 10. 26 || 10. 59 10. 93
400 10. 00 10. 33 10. 67 11. 02 11. 38 || 11. 75 | 12, 13 12, 52
450 11. 23 11. 60 11. 98 12. 38 12. 78 13. 20 | 13. 62 14. 06
500 12. 40 12. 81 13. 23 13. 67 14. 11 14. 57 | 15. 04 15. 52
550 13. 51 13. 96 14. 42 14. 90 15. 38 15. 88 | 16. 39 16. 92
600 14. 58 15. 06 15. 56 16. 07 16. 59 || 17. 13 || 17. 68 18. 25
650 15. 57 16. 09 16. 62 17, 17 17, 73 18, 30 | 18. 89 19. .50
700 16. 53 17. 08 17. 64 18, 22 18. 82 | 19. 43 | 20, 06 20. 70
750 17. 43 18. 01 18. 60 19. 22 19. 84 || 20. 49 21. 15 21. 82
800 18. 29 18. 90 19. 52 20, 17 20. 82 || 2:1. 50 22, 19 22. 90
850 19. 10 19. 74 20. 39 21. 06 21. 75 22, 45 23, 18 23. 92
900 19. 87 20, 53 21. 21 21. 91 22. 62 || 23. 35 | 24. 11 24, 88
950 20. 60 21. 29 21. 99 22. 72 23. 46 24, 22 || 25. 00 25. 80
1,000 21. 29 22. 00 22. 73 23. 47 24, 24 || 25. 03 25. 83 26. 66
1,050 21. 95 22. 68 23. 43 24, 20 24, 99 || 25, 80 || 26. 63 27. 48
1,100 22. 58 23. 33 24. 10 24, 89 25, 70 26. 54 27, 39 28. 27
1, 150 23. 17 23. 94 24. 73 25. 54 26, 38 27. 23 28. 11 29. 01
1,200 23. 75 24. 54 25. 35 26, 18 27. 04 || 27. 91 || 28. 81 29. 74
1,250 24, 28 25. 09 25. 92 26. 77 27. 64 28, 54 29. 46 30, 40
1,300 24. 80 25. 63 26. 48 27, 35 28, 24 29, 15 30. 09 31. 06
1,350 25. 30 26. 14 27. 00 27. 89 28. 80 29, 73 || 30. 69 31. 67
1,400 25. 77 26. 63 27. 51 28. 41 29, 34 || 30, 29 || 31. 27 32. 27
1,450 26. 22 27. 09 27, 98 28. 91 29, 85 || 30, 81 || 31. 81 32. 82
1,500 26. 65 27. 54 28. 45 29. 39 30, 34 31. 33 32. 34 33. 37
1,550 27. 07 27, 97 28. 89 29. 84 30. 82 31. 82 || 32. 84 33. 89
1,600 27. 47 28. 39 29. 33 30, 29 31, 28 32. 29 || 33. 34 34. 40
698
Circular of the National Bureau of Standards
TABLE 145.-Elevation of the boiling point * of sucrose solutions above that of water
at various vapor pressures—Continued
Vapor pressure, pounds per square inch
2.8886 || 3.6269 || 4.5.193 5.5908 º 8.3837 || 10.168
Vapor pressure, millimeters of mercury
Solids -
per º Brix 149.38 187.56 233.71 289.13 355.22 || 433.56 525.84
g. O
Water
Boiling point of water, degrees centigrade
60 65 70 75 80 85 90
Elevation, degrees centigrade, above the boiling point of water
80 PERCENT PURITY 9
50 33. 33 0. 77 0.80 0. 83 0. 85 0. 88 0.91 0. 95
100 50, 00 1. 85 1. 92 1, 99 2. 06 2. 13 2. 20 2. 28
150 60 00 3. 02 3. 13 3. 24 3. 35 3. 47 3. 59 3. 71
200 66. 67 4. 23 4. 38 4. 53 4, 69 4. 85 5. 02 5. 19
250 71. 43 5. 45 5. 64 5. 84 6. 04 6. 25 6. 47 6. 69
300 75. 00 6. 64 6. 88 7. 12 7. 37 7. 63 7. 89 8. 16
350 77. 78 7. 81 8. 09 8. 38 8. 67 || 8. 97 || 9, 27 9. 59
400 80. 00 8. 95 9. 27 9. 59 9, 93 || 10. 27 | 10. 62 10. 98
450 81. 82 10. 03 10. 39 10. 76 11. 13 | 11. 51 | 11. 91 12. 31
500 83. 33 11. 06 11. 46 11. 86 12. 27 | 12, 70 || 13, 13 13. 58
550 84. 62 12. 04 12. 48 12. 91 13. 36 || 13. 83 || 14. 30 14. 78
600 85. 71 12. 98 13. 44 13. 91 14. 40 14. 90 | 15. 40 15. 93
650 86. 67 13. 85 14, 35 14. 85 15. 37 | 15. 90 | 16. 45 17, 00
700 87. 50 14. 69 15. 22 15. 75 16. 30 | 16. 87 | 17. 44 18. 03
750 88. 24 15. 48 16. 04 16. 60 17, 18 17. 78 18, 38 19. 01
800 88. 89 16. 23 16. 89 17. 49 18. 10 | 18. 72 | 19. 36 20 02
850 89, 47 16. 94 17. 55 18. 17 18. 80 | 19. 45 20, 11 20. 80
900 90, 00 17. 61 18. 24 18. 89 19. 54 20. 22 20. 91 21. 62
950 90. 48 18, 25 18. 90 19. 56 20. 25 20. 95 || 21, 66 22. 40
1,000 90. 91 18, 86 19. 53 20. 22 20. 92 || 21. 65 22. 39 3. 15
1,050 91. 30 19. 43 20. 12 20. 83 21. 56 22. 30 || 23. 07 23. 85
1,100 91. 67 19, 97 20. 68 21. 41 22. 16 22. 93 || 23, 71 24, 51
1, 150 92. 00 20. 50 21. 23 21. 98 22. 74 || 23. 53 24. 33 25. 16
1,200 92. 31 20. 98 21. 74 22. 50 23, 28 24, 09 || 24, 91 25, 76
1,250 92. 59 21. 46 22. 23 23. 01 23. 81 24, 63 || 25. 47 26. 34
1,300 92. 86 21. 91 22. 69 23. 49 24. 31 25. 15 26. 01 26. 89
1,350 93. 10 22. 33 23. 13 23. 95 24. 78 25. 64 26. 52 27. 41
1,400 93. 33 22. 74 23. 55 24, 38 25. 23 26. 10 || 27. 00 27. 91
1,450 93. 55 23. 14 23. 96 24. 81 25. 67 || 26. 56 27. 47 28. 40
1,500 93. 75 23. 51 24, 35 25. 21 26. 09 || 26. 99 || 27. 91 28. 86
1,550 93. 94 23. 88 24. 73 25, 60 26. 49 27. 41 || 28. 35 29. 31
1,600 94. 12 24, 22 25. 09 25. 97 26. 87 27, 80 28. 75 29. 73
a See footnote a, p. 694–5.
b See footnote b, p. 696.
Polarimetry, Saccharimetry, and the Sugars
699
TABLE 145.-Elevation of the boiling point * of sucrose solutions above that of water
at various vapor pressures–Continued
Vapor pressure, pounds per square inch
12.260 | 1.4.696 || 17.520 | 20.779 || 24,519 || 28.795 || 33.661 || 39.177
Vapor pressure, millimeters mercury
Solids
"... ." G84.02 || 76000 906.04 || 1074.58||1267.99 |1489.12 wn 2026.03
Water -
Boiling point of water, degrees centigrade
95 100 105 110 115 120 125 130
Elevation, degrees centigrade, above the boiling point of water
80 PERCENT PURITY b
50 0. 98 1. 01 1. 04 1. 08 1. 11 1. 15 1. 19 1. 22
100 2. 35 2. 43 2. 51 2. 59 2. 68 2. 76 2. 85 2. 94
150 3. 83 3. 96 4. 09 4. 23 4. 36 4. 50 4. 65 4. 80
200 5. 36 5. 54 5. 72 5. 91 6. 10 6. 30 6. 50 6. 71
250 6. 91 7. 14 7. 38 7. 62 7. 87 8. 12 8. 38 8. 65
300 8. 43 8. 71 9. O0 9. 29 9. 60 9. 91 || 10. 23 10. 55
350 9. 9] 10. 24 10. 58 10. 93 11. 28 11. 65 | 12. 02 12. 41
400 11. 35 11. 73 12. 12 12. 52 12. 92 || 13. 34 || 13. 77 14. 21
450 12. 73 13. 15 13. 58 14. 03 14. 49 || 14. 96 || 15. 44 15. 93
500 14. 03 14. 50 14. 98 15. 47 15. 98 || 16. 49 17. 03 17. 57
550 15. 28 15. 79 16. 31 16, 85 17. 40 17. 96 || 18. 54 19. 13
600 16. 46 17. 01 17. 57 18. 15 18. 74 | 19. 35 | 19. 97 20. 61
650 17. 57 18. 16 18. 76 19. 38 20. 01 || 20. 66 21. 32 22. 00
700 18. 64 19. 26 19. 90 20. 55 21. 22 || 2:1. 91 22. 62 23. 34
750 19. 65 20. 30 20. 97 21. 66 22. 37 || 23. 09 || 23. 84 24, 60
800 20. 69 21. 38 22. 09 22. 8] 23. 56 24, 32 || 25. 10 25. 91
850 21. 49 22, 21 22. 94 23. 70 24. 47 25, 26 || 26. 08 26. 91
900 22, 35 23. 09 23. 85 24. 64 25. 44 26, 26 || 27. 11 27. 98
950 23. 15 23. 92 24. 71 25, 52 26. 36 27, 21 28. 09 28. 98
1,000 23. 92 24. 72 25. 54 26. 38 27. 24 28. 12 || 29. 03 29. 95
1,050 24. 65 25. 47 26. 31 27, 18 28. 06 || 28. 97 || 29. 91 30. 86
1,100 25. 34 26, 18 27. 04 27. 93 28. 85 29. 78 || 30. 74 31. 72
1,150 26. 00 26. 87 27, 76 28. 67 29. 61 || 30. 56 || 31. 55 32. 56
1,200 26. 62 27. 51 28. 42 29. 35 30, 31 || 31. 29 || 32. 30 33. 33
1,250 27. 22 28. 13 29. 06 30. 01 30. 99 || 32. 00 33. 03 34. 09
1,300 27, 80 28. 72 29. 67 30. 64 31. 64 || 32, 67 || 33. 72 34. 80
1,350 28, 34 29.28 30, 25 31. 24 32. 26 || 33. 31 || 34. 38 35. 48
1,400 28. 85 29. 81 30. 79 31. 81 32, 84 || 33. 91 || 35. 00 36. 12
1,450 29. 35 30. 33 31. 33 32. 36 33. 42 34, 50 | 35. 61 36. 75
1,500 29. 83 30. 82 31. 84 32, 88 33. 96 || 35. 06 || 36. 19 37. 34
1,550 30, 29 31. 30 32. 33 33. 40 34. 48 || 35. 60 36. 75 37. 93
1,600 30. 73 31. 75 32. 80 33. 88 34. 98 || 36. 12 || 37. 28 38.47

700
Circular of the National Bureau of Standards
TABLE 145.-Elevation of the boiling point " of sucrose solutions above that of water
at various vapor pressures–Continued
Vapor pressure, pounds per square inch
2.8886 3.6269
4.51.93
5.5908 6.8688 8.3837 10. 168
Vapor pressure, millimeters of mercury
Solids | - - I } --- : --- - -
*: º Brix | 1.49.38 187.56 233.71 289.13 355.22 433.56 525.84
water --- l - —--—- —-
t Boiling point of water, degrees centigrade
|
60 65 70 75 80 85 90
Elevation, degrees centigrade, above the boiling point of water
70 PERCENT PURITY b
- i
50 || 33. 33 0. 92 0. 96 0. 99 1. 02 | 1.06 | 1. 10 1, 13
100 50, 00 2. 20 2. 28 2. 36 2. 45 2. 53 2, 62 2. 7 |
150 60 00 3. 54 3. 67 3. 80 3. 93 4. 06 4. 20 4. 34
200 66, 67 4. 90 5. 07 5. 25 5. 43 5. 62 5. 81 6. () |
250 71. 43 6. 25 6, 47 6. 70 6, 93 7, 17 7. 42 7. (37
300 75. 00 7. 58 7. 85 8. 13 8. 41 8. 70 9. ()0 9. 3 |
350 77. 78 8. 89 9. 20 9. 53 9. 86 || 10. 20 | 10. 55 10. 9 |
400 80, 00 10. 15 10. 51 10. 88 11. 26 || 11. 65 | 12. 04 12. 45
450 8]. 82 11. 35 11. 76 12. 1 7 12. 59 || 13. 03 || 13. 48 13. 93
500 83. 33 12. 50 12. 95 13. 41 13. 87 | 1.4. 35 | 1.4. 84 15. 35
550 84. 62 13. 61 14. 10 14. 59 15. 10 | 15. 62 | 16. 16 16. 70
600 85. 71 14. 65 15. 17 15. 70 16. 25 | 16, 81 17. 39 17. 98
650 86. 67 15. 63 16. 19 16. 76 17. 34 17. 94 | 18. 56 19. 18
700 87. 50 16. 57 17. 16 17, 76 18, 38 | 19. 02 || 19. 67 20. 34
750 88. 24 17. 45 18. 08 18, 71 19. 37 20. 04 20, 72 21.42
800 88. 89 18. 30 18. 95 19. 62 20. 31 21. 01 || 21, 73 22. 46
850 89, 47 19. 09 19. 78 20. 47 21. 19 || 2:1. 92 22, 67 23. 44
900 90. 00 19. 86 20. 57 21. 29 22. 03 22, 79 23. 57 24, 37
950 90. 48 20. 57 21. 31 22. 06 22. 83 23. 62 24. 42 25. 25
1,000 90. 91 21. 25 22. 01 22. 79 23. 58 24. 40 || 25. 23 26. 09
1,050 91, 30 21, 90 22, 68 23. 48 24, 30 25, 14 26. 00 26, 88
1, 100 91. 67 22. 52 23. 32 24. 14 24. 99 || 25. 85 26. 73 27. 64
1, 150 92, 00 23. 10 23. 92 24, 77 25. 63 26. 52 27. 42 28. 35
1,200 92. 31 23. 66 24. 51 25, 37 26. 26 27 16 28. 09 29. 04
1,250 92. 59 24. 20 25. 06 25, 94 26, 85 27, 78 28. 73 29. 70
1,300 92. 86 24. 70 25. 58 26. 48 27. 41 || 28. 36 29. 32 30. 32
1,350 93. 10 25. 20 26. 10 27. 02 27. 96 28. 92 29. 91 30. 93
1,400 93. 33 25. 65 26. 57 27. 51 28. 46 29. 45 30, 46 31. 49
1,450 93. 55 26. () 27. 03 27. 98 28. 96 29. 96 || 30. 98 32. 03
1,500 93. 75 26. 52 27. 47 28. 44 29. 43 30 45 || 31. 49 32. 56
1,550 93. 94 26. 93 27. 90 28. 88 29, 89 30. 92 31. 98 33.06
1,600 94. 12 27, 33 28. 31 29, 31 30, 33 31. 38 32.45 33. 55
a See footnote a, p. 694-5.
b See footnote b, p. 696.
Polarimetry, Saccharimetry, and the Sugars
701
TABLE 145.-Elevation of the boiling point * of sucrose solutions above that of water
at various vapor pressures—Continued
Vapor pressure, pounds per square inch
12.260 14.696 || 17.520 20.779 24,519 || 28.795 || 33.661 || 39.177
Vapor pressure, millimeters of mercury
Solids
* .." 634.02 || 760.00 906.04 || 1074.58 1267.99 |sº 1740.77| 2026.03
Water
Boiling point of water, degrees centigrade
95 100 105 110 115 120 125 130
Elevation, degrees centigrade, above the boiling point of water
70 PERCENT PURITY b
50 1, 17 1. 21 1. 25 1, 29 1. 33 1. 38 1. 42 1. 47
100 2. 80 2. 89 2. 99 3. 08 3. 18 3. 29 3. 39 3. 50
150 4. 49 4. 64 4. 79 4. 95 5. 11 5. 28 5. 45 5. 62
200 6. 21 6. 42 6. 63 6, 85 7. O7 7. 30 7. 54 7. 78
250 7. 93 8. I9 8. 46 8. 74 9. O2 9. 32 9. 62 9. 92
300 9. 62 9. 94 10. 27 10, 61 10. 95 || 11. 31 || 11. 67 12. 04
350 11. 28 11. 65 12. 03 12, 43 12. 84 || 13. 25 | 13. 68 14. 12
400 12. 87 13. 30 13. 74 14. 19 14. 65 | 15. 13 | 15. 62 16. 12
450 14. 40 14, 88 15. 37 15. 88 16. 39 |- - - - - - - - - - - - - - - - - - - - -
50 15. 86 16. 39 16. 93 17. 49 18.06 || - - - - - - - - - - - - - - - - - - - -
550 17, 27 17. 84 18. 43 19. 04 19. 66 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
600 18, 58 19. 20 19. 83 20, 49 21. 15 |-|--|--|--|-------|-------
650 19. 83 20. 49 21. 17 21. 86 22. 58 - - - - - - - - - - - - - - - - - - - - -
700 21. 02 21. 72 22. 44 23, 18 23.93 - - - - - - - - - - - - - - - - - - - - -
750 22. 14 22. 88 23. 64 24, 41 25, 21 - - - - - - - - - - - - - - - - - - - - -
800 23. 22 23. 99 24. 78 25, 60 26. 43 || - - - - - - - - - - - - - - - - - -
850 24, 23 25. 03 25. 86 26, 71 27. 58 |- - - - - - - - - - - - - - - - - - - - -
900 25. 19 26. 03 26. 89 27, 77 28. 68 || - - - - - - |_ _ _ _ _ _ _ _ _ _ _ _ _ _
950 26. 10 26. 97 27, 86 28. 78 29, 72 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
1,000 26. 96 27. 86 28. 78 29, 73 30. 70 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
1,050 27, 79 28. 71 29. 66 30, 63 31. 63 || - - - - - - - - - - - - - - - - - - - -
1,100 28. 57 29. 52 30. 49 31, 50 32.53 - - - - - - - - - - - - - - - - - - - - -
1,150 29, 31 30, 28 31, 28 32. 31 33. 36 - - - - - - - - - - - - - - - - - - - - -
1,200 30. 02 31. 02 32. 04 33. 10 34. 18 - - - - - - - - - - - - - - - - - - - - -
1,250 30. 70 31. 72 32. 77 33, 85 34. 95 || - - - - - - - - - - - - - - - - - - - -
1,300 31. 34 32. 38 33. 45 34. 55 35. 68 - - - - - - - - - - - - - - - - - - - - -
1,350 31. 97 33. 03 34. 12 35. 24 36. 39 || - - - - - - - - - - - - - - - - - - - -
1,400 32. 55 33. 63 34. 74 35. 88 37.05 - - - - - - - - - - - - - - - - - - - - -
1,450 33. 11 34. 21 35. 34 36. 50 37. 69 |_ _ _ _ _ _ _ !--- - - - - - - - - - - -
1,500 33. 65 34, 77 35. 92 37, 10 38. 31 ||-------|-------|-------
1,550 34. 17 35. 31 36. 48 37, 68 38.90 - - - - - - - - - - - - - - - - - - - - -
1,600 34. 68 35. 83 37. 01 38. 23 39. 48 - - - - - - - - - - - - - - - - - - - - -
323414°–42—46
702
Circular of the National Bureau of Standards
TABLE 146.-Purity factors for use with dry-lead defecation 1
[The direct polariscope reading of the solution times the factor corresponding to
the Brix gives the coefficient of purity]

Brix
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
º, tº “s $º m - ºr sº tº * 260. 6336 || 130. 2660 | 86.8102 || 65. 0.829 || 52. 0461 || 43.3549 37. 1469 || 32, 4909 || 28. S695
25. 9725 || 23. 6022 || 21. 6269 || 19.9556 18, 5230 || 17. 2814 | 16. 1951 || 15, 2365 || 14. 3845 || 13. 6221
12.9360 | 12. 3152 11. 7508 || 11. 2355 10.7632 || 10.3286 9.9275 9. 5561 9. 21.13 8. 8901
8. 5905 8. 3102 8. 0473 7.8004 || 7.5680 || 7. 3490 || 7. 1420 | 6.9463 || 6.7608 6.5849
6. 41.78 6. 2588 6. 1074 5. 9630 || 5, 8253 5. 6936 5.5676 || 5.4470 || 5. 3314 5, 2206
5. 1142 5. 0120 4.9136 4, 8191 || 4. 7280 || 4.6402 || 4. 5555 || 4.4738 || 4. 3950 4.3.188
4. 2451 4, 1739 4. 1050 4,0382 3.9755 3, 9109 || 3.8501 || 3. 7912 || 3.7330 3. 6784
3. 6244 3. 5720 3. 5209 3. 4713 || 3.4231 || 3. 3761 || 3. 3304 || 3. 2858 || 3. 2424 3. 2001
3, 1589 3. 1186 3.0794 3.04.11 || 3. 0037 2.9671 2.9315 2.8966 2.8626 2.8.293
2. 7968 2, 764ſ 2. 7338 2. 7033 2.6735 | 2.6443 2.6157 | 2, 5877 2, 5603 2. 5334
2. 5071 2. 4813 2. 4560 2.4312 || 2.4068 || 2. 3830 || 2. 3596 || 2. 3366 || 2, 3140 2. 2919
2. 2701 2. 2488 2, 2278 2. 2072 2, 1870 2. 1671 2. 1475 2. 1283 2. 1095 2. 0909
2. 0727 2. 0547 2.0370 2. ()197 || 2, 0026 | 1.9858 || 1. 9692 | 1.9529 | 1.9369 1. 921.1
1.9056 1. 8903 1. 8752 1. S603 || J. 8457 | 1. 8313 | 1.8171 | 1.8031 | 1.7893 1.7757
1. 7623 1, 7491 1. 7361 1. 7233 | 1. 7106 | 1.6981 | 1.6858 1. 6737 | 1, 66.17 1, 6499
1.6382 1, 6267 1, 6154 1, 6042 | 1, 5931 | 1. 5822 | 1. 57.14 | 1. 560S | 1. 5503 1. 5399
1, 5296 1. 5195 1. 5095 i. 4997 | 1. 4899 || 1.4803 | 1.4708 || 1.4614 | 1.4521 1.4429
1. 4338 1. 4249 1. 4160 1. 4072 | 1.3986 | 1.3900 | 1. 384 1. 3732 | 1.3649 1, 3567
1. 3487 1. 3407 1. 3328 1.3249 | 1.3172 | 1.3095 | 1. 3020 | 1. 2945 1, 2871 1.2797
1. 2725 1, 2653 1. 2582 1. 2511 | 1. 2442 | 1.2373 || 1, 2305 | 1. 2237 | 1. 2171 1. 2104
1. 2039 1. 1974 1. 1910 1. 1846 | 1. 1784 1. 1721 | 1. 1660 | 1. 1598 1, 1538 1. 1478
1. 1419 1. 1360 1. 1302 1. 1244 | 1. 1187 | 1. 1130 | 1. 1074 | 1. 1018 | 1.0963 1. 0909
1. 0855 1. 0801 1. ()748 1. 0696 | 1.0643 | 1.0592 | 1. 0540 | 1.0490 | 1. 0439 J. 0389
1. 0340 1. 0291 1.0242 1. 0194 | 1. 0146 1, 0099 || 1.0052 | 1, 0005 || 0.9959 0. 9913
0. 9868 0. 98.23 0.977S 0.9734 || 0.9690 || 0.9647 0. 9603 || 0.9560 . 95.18 . 9476
. 9434 |----------|----------
! E. W. Rice, Facts About Sugar 22, 1066 (1927).
Polarimetry, Saccharimetry, and the Sugars
703
TABLE 147.-International atomic weights, 1941
[Partial list]
Sym- Atomic Atomic Sym-| Atomic! Atomic
Element bol No. weight Element bol No. weight
Aluminum----| Al 13 || 26. 97 Magnesium---| Mg 12 24, 32
Antimony - - - - | Sb 51 |121. 76 Manganese - - - || Mn 25 | 54. 93
Arsenic - - - - - - As 33 || 74. 91 Mercury – - - - Hg 80 |200. 61
Barium - - - - - - Ba 56 |137. 36 Molybdenum - || Mo 42 95. 95
Bismuth - _ _ _ Bi 83 209. 00 Neon - - - - - - - - Ne 10 20, 183
Boron-------- B 5 | 10. 82 Nickel- - - - - - - Ni 28 58. 69
Bromine – – | Br 35 | 79. 916 Nitrogen - - - - - N 7 | 1.4. 008
Cadmium _ _ _ _ Col 48 |112. 41 Oxygen - - - - - - O 8 || 16. 0000
Calcium------ Ca 20 | 40. 08 Phosphorus--- P 15 30, 98
Carbon – - - - - - C 6 12. 010 Platinum-- - - - Pt 78 |195. 23
Chlorine - - - - - Cl 17 | 35. 457 Potassium_ _ _ _| K 19 || 39. 096
Chromium----| Cr 24 || 52. 01 Radium- - - - - - Ra. 88 |226. 05
Cobalt- - - - - - - CO 27 | 58. 94 Selenium - - - - Se 34 || 78. 96
Copper------- Cu 29 || 63. 57 Silicon - - - - - - - Si 14 || 28. 06
Fluorine_-_ _ _ _ F 9 | 19. 00 Silver-- - - - - - - Ag 47 |107. 880
Gallium-- - - - - Ga 31 69. 72 Sodium - - - - - - Na. 11 22. 997
old--------- Au 79 |197. 2 Strontium - - || Sr 38 87. 63
Helium _ _ _ _ _ _ He 2 4. 003 Sulfur--__ _ _ _ _ | S 16 || 32. 06
Hydrogen - - - - | H 1. 1. 0080 || Tin -- - - - - - - - - Sn 50 || 1 18. 70
Iodine - - - - - - - I 53 |126. 92 Tungsten--- - - W 74 |183. 92
Iridium _ _ _ _ _ _ Ir 77 |193. 1 Uranium - - - - - U 92 |238. 07
Iron --------- Fe 26 55. 85 Vanadium- - - -] W 23 50. 95
Lead--------- Pb 82 |207. 21 Zinc - - - - - - - - - Zn 30 || 65. 38
Lithium--- - - - Li 3 6. 940
=
TABLE 148.-Optical rotation and melting point of certain sugars and sugar derivatives
[This table lists the melting points, optical rotations, and molecular weights of a selected group of sugars and derivatives.
Unfortunately, there is no universally accepted nomenclature for the sugar derivatives, and therefore names have been selected to
conform as far as possible with the general principles of established nomenclature for organic compounds. The alpha and beta modifica-
tions of the heptoses and higher sugars have been named according to the suggestion of Isbell, while the alpha and beta names in common
use have been retained for the lower sugars.
With only a few exceptions (where the importance of the compound makes inclusion desirable) only crystalline compounds are given.
The derivatives are listed under the parent sugar in the following order: hydrazones, osazones, methyl ethers, acetates, halogeno-acetates,
glycosides, acetone derivatives, acids, lactones, amides, hydrazides, and glycals. A comprehensive list of well-defined crystalline derivatives
of sucrose and glucose is included.
For the calculation of the molecular weights, the 1938 International Atomic Weights were used. The specific rotations are given for
the D line of sodium and for a temperature of 20° C except where a different wave length is given or a different temperature is noted in
parentheses. The literature to January 1, 1938, has been covered, and the more important compounds have been included.]
H H H H
d-ALLOSE CH3OH−C—C—C–C––CHO
OH OH OH OH
Molec- tº
* M lt 20 & * t
Substance º Formula wº º |o]}}'' [M] ‘. Solvent
oC g/100 ml
3-d-Allose-------------------------- [1] C6H12O6 180. 16|128–128. 5| 2–0. 2— — — 14. 4 — 40 5| H2O
d-Allonic Y-lactone – - - - - - - - - - - - - - - - [2] C5H10O3 178. 14| 97–120 – 6. 8 — 1, 210 11| H2O
d-Allonic phenylhydrazide- - - - - - - - - - - [3] C19H18O3N2 286. 28|- - - - - - - - - +25. 9 + 7,410 1| H2O
3.
OH OH OH OH
l-ALLOSE CH2OH C C C (` CHO
H H H H
B-l-Allose-------------------------- [4] C6H12O6 | 180. 161128–129 — 1. 90— — 13. 9
l-Allose p-bromphenylhydrazone- - - - - - [4] C12H17O5N2Br 349. 19|141–145 + 6. 4
l-Allonic Y-lactone- - - - - - - - - - - - - - - - - - [4] 6.Ll 10\_J6 178. 14|130 + 6. 3 (25°)
l-Allonic phenylhydrazide_--_ _ _ _ _ _ _ _ _ [5] C19H18O3N2 286. 28|142–145 ||—23. 6
— 350
i
|
t
|
H2O
EtOH
H2O
1 These values are read at 20°C, except where the temperature is specified otherwise in parentheses.
* Values from reference [1] extrapolated to zero time.
REFERENCES
|} F. P. Phelps and F. J. Bates, J. Am. Chem. Soc. 56, 1250 (1934).
[2] P. A. Levene and W. A. Jacobs, Ber. deut. chem. Ges. 43, 3141 (1910).
[3] P. A. Levene and G. M. Meyer, J. Biol. Chem. 31, 625 (1917).
[4] W. C. Austin and F. L. Humoller, J. Am. Chem. Soc. 55, 2167 (1933); 56, 1153 (1934).
[5] F. L. Humoller, W. F. McManus, and W. C. Austin, J. Am. Chem. Soc. 58, 2479 (1936).
=
TABLE 148.-Optical rotation and melting point of certain sugars and sugar derivatives–Continued
H H H OH
d–ALTROSE CH3OH−—C— C C C CHO
OH OH OH H
Molec- e ſ
** Refer- Melting I Concen-
Substance €Il CGS Formula wº t| point sº [o]}} [M] tration Solvent
--" —- –
oC g/100 ml
(3-d-Altrose------------------------- [1] C6H12O6 180. 16|103–105 +32. 69 |_ _ _ _ _ _ _ _ _ 8| H2O
d–Altrose dibenzylmercaptal____ _ _ _ _ _ _ [1] C20H26O3S3 410. 53|121–122 ––39. 4 + 16, 200 3| Pyridine
Diacetone-d-altrose_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ [2] 121120V6 260. 28' 89 +28. 27 + 7, 400 2| Acetone
Methyl tetramethyl-o'-d-altroside - - - - - [4] 11H22O6 250. 29| 76–78 + 97.4 +24, 400 1| EtOH
Methyl 2-methyl-o-d-altroside - - - - - - - | 5] CŞH16O6 208. 21 81–83 + 111.6 (15°) + 23, 200 1 CHC13
s

OH OH OH. H.
l–ALTROSE CH3OH C C C C CHO
H H H OH
B-l-Altrose------------------------- [3] C6H12O6 180. 16|107–109. 5 — 28.8— — 32.3 — 5, 180 4 H2O
l–Altrose benzylphenylhydrazone- - - - - [3] C10H24O5N2 360. 401147–148 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _|_ _ _ _ — — — — — I — — — — — — — —
l–Altronic acid---------------------- [6] C6H12O7 196. 16||110 —-8.1 — 1, 600|_ _ _ _ _ _ _ _ H2O
l–Altronic phenylhydrazide----- - - - - - - [6] C12H18O8 N2 286. 28, 151—152 +18.4 + 5, 300|_ _ _ _ _ _ _ _ 2O
| These values are read at 20°C, except where the temperature is specified otherwise in parentheses.
* Equilibrium rotation; no mutarotation recorded.
REFERENCES
[1] N. K. Richtmyer and C. S. Hudson, J. Am. Chem. Soc. 57, 1716 (1935).
[2] M. Steiger and T. Reichstein, Helv. Chim. Acta 19, 1011 (1936).
§ W. C. Austin and F. L. Humoller, J. Am. Chem. Soc. 56, 1153 (1934).
4] D. S. Mathers and G. J. Robertson, J. Chem. Soc. 1933, 1076.
5) G. J. Robertson and C. F. Griffith, J. Chem. Soc. 1935, 1193.
F. L. Humoller, W. F. McManus, and W. C. Austin, J. Am. Chem. Soc. 58,2479C 1936).
3.
TABLE 148.-Optical rotation and melting point of certain sugars and sugar derivatives—Continued
OH OH H
l-ARABINOSE CH2OH C–C C CHO
H H OH
Molec- tº { -
Substance º: Formula º, ** [o]}' [M] ºº Solvent
weight
oC g/ 100 ml
3-l-Arabinose---------------------- [1, 2, 3] C5H10O; 150. 13| 160 -- 190.6— + 104.5 + 28, 610|_ _ _ _ _ _ _ _ H2O
o'-l-Arabinose. CaCl2.4H2O-- - - - - - - - - [1, 3, 4} C5H18O, CaOlg 333. 19. 204 -- 34.7— — — 48.0 + 11, 560 9| H2O
l-Arabinose benzylphenylhydrazone.--| [ 5, 6] C18H22O4N2 330. 38 174 — 14.8— – 11.5 — 4, 890 – ... -- - - - - MeOH
2,3,4-Trimethyl-o'-l-arabinose - - - - - - - | 7, 8] CaFI16O5 192. 21 281–82 | –– 16.4 + 3, 150 5| CHCl3
1, 1’,2,3,4,5-Hexaacetyl-l-arabinose ---| [9] C17H24O12 420. 36|| 89. 5 –-27 (27°) – 11, 300 4| CHCl3
1,2,3,4-Tetraacetyl-o'-l-arabinose----- 10] 13PilgO) 3.18. 28 97 +42.5 (22°) + 13, 500 3. CHCl3
1,2,3,4-Tetraacetyl-3-l-arabinose--- - - [10] 13 HisOg 318. 28' 86 + 147.2 (21°) +46, 800 5| CH Cla
2,3,4,5-Tetraacetyl-l-arabinose. ------ [11] C18H18Og 318, 28 113–115 – 65.6 (27°) –20, 880 4| CHCla
1-Chloro-1,2,3,4,5-pentaacetyl-l-arab- [12] C15H21O10Cl 396. 78 109–110 – 96 (25°) — 38, 100 4| CHCla
II) OS62.
1-Bromo-1,2,3,4,5-pentaacetyl-l-arab- [12] C15H2O10 Br 441. 24 130–131 – 134 (23°) –59, 100 4| CHCl3
1 In OSG.
1-Fluoro-2,3,4-triacetyl-3-l-arabinose-| [13] C11H15O1F 278. 23| 117–118) -- 1:38.2 +38, 500 2 CHCla
1-Chloro-2,3,4-triacetyl-3-l-arabinose— [13] C11H15O1Cl 294, 69. 146–147| -i-244. 4 + 72, 000 2| CHCla
1-Bromo-2,3,4-triacetyl-3-l-arabinose-| [13] C11H15O1 Br 339. 15| 138–139|| -- 287.1 +97, 400 2| CHCla
1-Iodo-2,3,4-triacetyl-3-l-arabinose---| [13] 11H15O;I 386. 15 d + 339.1 + 130,900 2 CHCl,
Methyl ox-l-arabinopyranoside-- - - - - - [14] 611 12V J5 164. 16| 131 + 17.3 +2, 840 3| H2O
Methyl 3-l-arabinopyranoside_ _ _ _ _ _ _ [14] C6H12O5 164. 16. 169 –– 245.5 +40, 300 7| H2O
Methyl triacetyl-3-l-arabinopyrano- [10] C19H18Os 290. 27| 85 + 182.0 (23°) +52, 800 4| CHCl,
side.
Methyl trimethyl-o'-l-arabinopyrano- | [8, 15] CoEI18O5 206. 24. 46–48 || -- 46.2 +9, 530 1| H2O
side.
Methyl trimethyl-8-l-arabinopyrano- | [15] CoEI 1805 206. 24. 44–46 -i- 250 + 51, 600 1| H2O
side.
s
l-Arabonic acid------------- - - - - - - - [16, 17] C5H10O6 166. 13| 111–116 — 9.S — 1, 630 5 H2O
l-Arabonic Y-lactone – - - - - - - - - - - - - - [16, 19] C5H8O; 148. 11| 95–98 || — 71.6 — 10, 600 5 H2O
l-Arabonic phenylhydrazide-- - - - - - - - [20] C11H16O5N2 256. 26, 215 ----------------|---------|--------|---------.
l-Arabonic amide- - - - - - - - - - - - - - - - - - [21] C5H1105.N 165. 15| 136 + 37.5 + 6, 190 5 H2O
l-Arabinal- - - - - - - - - - - - - - - - - - - - - - - - [22, 23, C5H8O3 116. 11| 81–83 – 202.8 (19°) — 23, 550 H2O
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
2 Possibly contaminated by the beta isomer.
REFERENCES
[1] H. S. Isbell and W. W. Pigman, J. Research NBS 18, 141 (1937) RP969; J. Org. [12] M. L. Wolfrom and M. Konigsberg, J. Am. Chem. Soc. 60, 288 (1938).
Chem. 1, 505 (1937). 13] D. H. Brauns, J. Am. Chem. Soc. 46, 1484 (1924).
[2] C. N. Riiber and N. R. Sørensen, Kgl. Norske Videnskab. Selskabs, Skrifter, No. 7 [14] C. S. Hudson, J. Am. Chem. Soc. 47,265 (1925).
- (1937) - [15] E. L. Hirst and G. J. Robertson, J. Chem. Soc. 127, 358 (1925).
[3] E. M. Montgomery and C. S. Hudson, J. Am. Chem. Soc. 56, 2074 (1934). 16] H. S. Isbell and H. L. Frush, BS J. Research 11, 649 (1933) RP613.
[4] W. C. Austin and J. P. Walsh, J. Am. Chem. Soc. 56, 934 (1934). 17 FC. Rehorst, Ber. deut. chem. Ges. 63, 2279 (1930).
[5] F. Votoček, F. Valentin, and O. Leminger, Coll: Trav. Chim. Czech. 3, 250 (1931). [18] R. Hauers and B. Tollens, Ber. deut. chem. Ges. 36, 3321 (1903).
[6] O. Ruff and G. Ollendorff, Ber. deut. chem. Ges. 32, 3234 (1899). 19| E. Fischer and O. Piloty, Ber, deut. chem. Ges. 24, 4219 (1891).
[7] T. Purdie and R. E. Rose, J. Chem. Soc. 89, 1207 (1906). 20] E. Fischer, Ber. deut, chem. Ges. 23, 2625 (1890).
[8] H. T. Neher and W. L. Lewis, J. Am. Chem. Soc. 53, 4416 (1931). 21] C. S. Hudson and S. Komatsu, J. Am. Chem. Soc., 41,1141 (1919).
[9] M. L. Wolfrom, J. Am. Chem. Soc. 57, 2498 (1935). 22] W. C. Austin and F. L. Humoller, J. Am. Chem. Soc. 54, 4749 (1932).
[10] C. S. Hudson and J. K. Dale, J. Am. Chem. Soc. 40,995 (1918). 23] M. Gehrke and F. X. Aichner, Ber. deut. chem. Ges. 60, 918 (1927).
[11] M. L. Wolfrom and M. R. Newlin, J. Am. Chem. Soc. 52, 3620 (1930). 24] J. Meisenheimer and H. Jung. Ber, deut. chem. Ges. 60, 1462 (1927).
E
:-
TABLE 148.-Optical rotation and melting point of certain sugars and sugar derivatives—Continued
CELLOBIOSE (4-(6-d-glucopyranosido)-d-glucose)
Molec- || Melt-
Substance Refer- Formula ular ing [a]?' [M] º º Solvent
€In CeS weight | point I’a U1OI).
oC g/100 ml
8-Cellobiose - - - - - - - - - - - - - - - - - - - - - - - - - [ 1, 2] C12H22O11 342. 30|225 + 14.2–3. –– 34.6 + 4, 860 8 H2O
Cellobiose phenylosazone - - - - - - - - - - - - - [4, 5] C24H32O0 N4 520. 53|198–200 – 6.5 (18°) –3, 400 1 º
Heptamethyl-o-cellobiose-- - - - - - - - - - - - [6] C19H26O11 440, 48|105–110 + 53— --40ſ of Järs. --23, 000 1| H2O
Octaacetyl-aldehydo-cellobiose -- - - - - - - - [7] C28H38O16 678, 59| Sirup - + 17.7 |-------- 3| CHCl3
Octaacetyl-o-cellobiose -- - - - - - - - - - - - - - [3, 8] C28H38O19 678. 59|229 + 41.0 +27, 800 6| CHC13
Octaacetyl-3-cellobiose_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ [8] C28H38O16 678. 59|202 — 14.7 — 10, 000 5 CHCla
1-Fluoro-heptaacetyl-a-cellobiose- - - - - - [9] C26H35017F 638. 54|187 + 30.6 + 19, 500 2| CHCl3
1-Chloro-heptaacetyl-o-cellobiose - - - - - - [9, 10] C26H35017Cl 655. 00|200–201| + 71.7 +47, 000 2| CHCl3
1-Bromo-heptaacetyl-o-cellobiose - - - - - - [9, 11] C26H35017 Br 699. 46|180 d. +95.8 +67, 000 2| CHC13
1-IOdo-heptaacetyl-o-cellobiose-- - - - - - - [9, 11] C26H350,71 746. 46|160–170 + 125.7 +93, 800 2| CHCl3
Methyl ox-cellobioside- - - - - - - - - - - - - - - - [12] C15H24O11 356. 32|144–145|| --96.8 +34, 490 1| H2O
Methyl 3-cellobioside_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ [13] C15H24O11 356. 32|193 — 19.1 (17°) — 6, 810 9| H2O
Methyl heptaacetyl-o-cellobioside - - - - - [12] C27H38O18 650. 58|185 + 55.7 +36, 200 1| CHCl3
Methyl heptaacetyl-3-cellobioside_--_ _ _ [14] C27H38018 650. 58|187 — 25.7 — 16, 720 6. CHCl3
Methyl heptamethyl-8-cellobioside----- [15,16,17] C20H38011 454. 51 | 86 — 15.9 –7, 230 1 2O
Cellobial--------------------------- [18, 19) C19H2009 308. 28|175—176 -– 1.0 + 300 9| H2O
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
REFERENCES
§ H. S. Isbell, heretofore unpublished measurement. [10] Zd. H. Skraup and J. Koenig, Monatsh. 22, 1033 (1901).
[2] F. C. Peterson and C. O. Spencer, J. Am. Chem. Soc. 49, 2822 (1927). Zd. H. Skraup and E. Geinsperger, Monatsh. 26, 1459 (1905).
[3] H. Friese and K. Hess, Liebigs Ann. Chem. 456, 38 (1927). {} #. Fºº (*.*. *::: #'ſ." Ges. 43, 2537 (1910).
É Wº...º.º.º. º chem. Ges. 61, 932 (1928). # f;. Heiſerich, A. ioewa, wº. N ippe, and H. Riedel, Z. physiol, Chem. 128, 141 (1923).
iſ K. Frºntº. º. Andersºn. Yao, K. Friedrich, and N. K. Richtmyer, É $:#;"| "Wºłºś."
Ber. deut. Chem. Ges. 63, 1961 (1930). • *-*. s *** * ... < *-*.*.*. s *...* ºf A s
jºr |Ul 5 ( ) jºy [16] F. Micheel and O. Littman, Liebigs. Ann. Chem, 466, 130 (1928).
[7] M. L. Wolfrom and S. Soltzberg, J. Am. Chem. Soc. 58, 1783 (1936). [17] K. Hess and K. Dziengel, Ber. deut. chem. Ges. 68, 1594 (1935).
[8] C. S. Hudson and G. M. Johnson, J. Am. Chem. Soc. 37, 1276 (1915). [18] E. Fischer and K. v. Fodor, Ber. deut. chem. Ges. 47, 2060 (1914).
[9] D. H. Brauns, J. Am. Chem. Soc. 48, 2782 (1926). [19] M. Bergmann and H. Schotte, Ber. deut. chem. Ges. 54, 1570 (1921).
e
E
CELTROBIOSE (4-(3-d-GLUCOPYRANOSIDO)-d-ALTROSE)
Molec- º
Substance º: Formula ular ** [o]} [M] º Solvent
weight
oC g/100 ml
Celtrobiose. H2O - - - - - - - - - - - - - - - - - - - - - - - - - [1] C12H24O12 360. 31 133–148 + 13.6 -- 4, 900 5 H2O
Heptaacetyl-ol-celtrobiose-- - - - - - - - - - - - - - - - [1] C28H36O18 636. 55 130–131|+22.3— -- 15.1 |+|14, 200 5 CHCl3
Heptaacetyl-3-celtrobiose *- - - - - - - - - - - - - - - - [1] C28H36O18 636. 55|- - - - - - - - - +3.9— + 15.1 |+ 2, 500 10 CHCl3
Octaacetyl-o-celtrobiose -- - - - - - - - - - - - - - - - - [1] C28H38O16 67s 59 (#;"|14so +32, 600 4| CHCl3
Octaacetyl-3-celtrobiose - - - - - - - - - - - - - - - - - - [1] C28H38O16 678, 59% º }– 13.0 — 8, 800 6| CHCl3
Heptaacetylceltrobiose - - - - - - - - - - - - - - - - - - - [1] C26H36O18 636. 55| 216 + 1.0 + 600 1 CHCls
1-Chloro-heptaacetyl-o-celtrobiose - - - - - - - - - [1, 2] C26H35017Cl 655. 00. 141–142|+ 64.2 +42, 000 4. CHCl3
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
2 Separates as monoetherate. Rotation calculated on solvent-free basis.
REFERENCES
É N. K. Richtmyer and C. S. Hudson, J. Am. Chem. Soc. 58, 2534 (1936).
[2] C. S. Hudson, J. Am. Chem. Soc. 48, 2002 (1926).
E.
TABLE 1.48.—Optical rotation and melting point of certain sugars and sugar derivatives—Continued
H OH OH. H.
CHONDROSAMINE CH2OH C C C C—CHO
OH H H NH2
Mol
. () €C- & -
Substance º: Formula ular Mºº [a]}' [M ] º: Solvent
weight pOlnt F3, U1Ol]
oC g/100 ml
Pentaacetyl-o'-d-chondrosamine-- - - - - - - - - - - - - - [ 1, 2] C15H23C)10N 389. 35 183 |+ 101.3(18°)|+39, 400 2 CHCla
Pentaacetyl-3-d-chondrosamine_-_ _ _ _ _ _ _ _ _ _ _ _ _ [1, 2] 15H23C)10N 389. 35 235 d. |-|- 1 1.0 + 4, 300 1 CHCl,
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
REFERENCES
|ll C. S. Hudson and J. K. Dale, J. Am. Chem. Soc. 38, 1433 (1916).
[2] P. A. Levene, J. Biol. Chem. 31, 609 (1917).
DESOXY SUGA RS
Molec- || Melt-
Tº gº e * * Refer- - * .. 20 1 .. Concen-
Substance €I) CéS Formula ular ing [o]}. [M] tration Solvent
weight | point,
oC g/100 ml
2-Desoxy cellobiose-- - - - - - - - - - - - - - - - - - - - - | 1, 2]| C12H22O10 326. 30|184-200 + 23.2 (21°) + 7, 570 H2O
3-d-2-I)esoxyglucose - - - - - - - - - - - - - - - - - - - - [3, 4 || C6H12O5 164. 16|148 + 15.0— --90.2% |_ _ _ _ _ _ _ _ 2. Pyridine
B-d-2-Desoxygalactose--- - - - - - - - - - - - - - - - - [5] C6H12O5 164. 16|121 -|- 40.8— + 60.53 + 6, 700 4| H2
B-d-2-Desoxyxylose - - - - - - - - - - - - - - - - - - - - - [6] C5H10O. 134, 13 92–96 || – 22.54–5 – 2.0 (22°) |_ _ _ _ _ _ _ _ 2 H2O
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
* Rotations at 5 minutes and 24 hours.
* Complex mutarotation.
4 Rotation after several minutes.
:
REFERENCES
| M. Bergmann and W. Breuers, Liebigs Ann. Chem. 470, 38 (1929).
| W. N. Haworth, E. L. Hirst, H. R. L. Streight, H. A. Thomas, and J. I. Webbe, J. Chem. Soc. 1930, 2636.
| M. Bergmann, H. Schotte, and W. Leschinsky, Ber. deut. chem. Ges. 55, 158 (1922).
| M. Bergmann, H. Schotte, and W. Leschinsky, Ber. deut. chem. Ges. 56, 1052 (1923).
3. H. S. Isbell and W. W. Pigman, J. Research N BS 22, 397 (1939) RP1190.
[6] P. A. Levene and T. Mori, J. Biol. Chem. 83, 803 (1929).
DIFRUCTOSE AN HYDRIDES
Molec- *
N Refer- * Melting 201 Concen- y
Substance en CeS Formula wº t point [o]}} [M] tration Solvent
oC | g/100 ml
Difructose anhydride I-- - - - - - - - - - - - - - - - - - - - - - - - [1, 2, 3, 4 || C12H26O10 324, 28 164 + 27.0 +8, 760 4| H2O
Hexaacetyldifructose anhydride I__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ [ 1, 4) C24H82O16 576. 50 137 -- 0.54 + 311 10 CHCl3
rl cli * § & +23.7 |_ _ _ _ _ _ _ _ 5| CHCls
Hexamethyldifructose anhydride I_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ [5, 6] C18H32O10 408. 44| Sirup--- {{#ſ - - - - - - - - - - 2 H2O
3,4,3',4'-tetraacetyldifructose anhydride I- - - - - - - - [6] C20H28O14 492. 43 1741; tº; } &#ol,
3,4,3',4'-Tetraacetyl-6,6'-dimethyldifructose anhy- | [6] C23H32O14 520. 48 128 + 10.8 + 5, 620 1| CH Cl,
dride I.
3,4,3',4', Tetraacetyl-6,6'-ditrityldifructose anhy- [6] C58 H56O14 977. 03 194| +21.1 +20, 610 4| CHC13
dride I.
6,6'-Ditrityldifructose anhydride I_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ [6] C50H18O10 808. 89 195|+20.4(22°)|+ 16, 500 2| CHCla
Difructose anhydride II- - - - - - - - - - - - - - - - - - - - - - - - [7] C12H20O10 324, 28 198 –– 13.8 +4, 470 9| H2O
* * • , — 28.2 — 11, 520 4| CHCl3
Hexamethyldifructose anhydride II- - - - - - - - - - - - - - [6] Cisłł32O10 408. 44 73 { + 6.0 +2, 450 4| H2O
Difructose anhydride III- - - - - - - - - - - - - - - - - - - - - - - [6, 7] C12H20010 324, 28 162 + 135.6 |-|-43, 970 8| H2O
& : £-- ide III------------- o 44 Sirup...|{i}#} |… 4| CHCl3
Hexamethyldifructose anhydride I [6] C18H32O10 408. 44| Sirup + 164.5 |_ _ _ _ _ _ _ _ 2 H2O
*— 1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
REFERENCES
[1] R. F. Jackson and S. M. Goergen, BS J. Research 3, 27 (1929) RP79.
[2] J. C. Irvine and J. W. Stevenson, J. Am. Chem. Soc. 51, 2197 (1929).
[3] R. F. Jackson and S. M. Goergen, BS J. Research 5, 733 (1930) RP224.
[4] E. W. Bodycote, W. N. Haworth, and C. S. Woolvin, J. Chem. Soc. 1932, 2390.
[5] W. N. Haworth and H. R. L. Streight, Helv. Chim. Acta 15, 693 (1932).
[6] E. J. McDonald and R. F. Jackson, J. Research NBS 24, 181 (1940) RP1277.
[7] R. F. Jackson and E. J. McDonald, BS J. Research 6, 709 (1931) RP299.
:
TABLE 148.-Optical rotation and melting point of certain sugars and sugar derivatives–Continued
H H OH
d–FRUCTOSE CH2OH C C C º CH2OH
OH OH H O
|
Molec- || Melt- ` ... ,
Substance º: Formula ular ing [a];" [M] º Solvent
weight | point &b
oC g/100 ml
8-d-Fructose - - - - - - - - - - - - - - - - - - - - - - - - [1] C6H12O6 180. 16|102–104 — 132.2— — 92.4 — 23, 820 4 #8
t —84. 12– – 53.5 ! . . . . . . . -- 1
3-Methyl-d-fructose— . . . . . . . . . . . . . . . . . . [2, 3] | Ch 14O6 194, 18|128–130 {-} 4.1— — 22. 1 – 14, 390 i Mºoh
£ºs * O i
3,4,6-Trimethyl-d-fructose--- . . . . . . . . . . . [4] CoPH18O8 222 24 sirup (iº III. | #6,
-Trim a th vl-d-fri i r + , , so º ſ — 23.8— – 51.8 – 11, 500 8| H2O
1,3,4-Trimethyl-d-fructose - . . . . . . . . . . . [5] CoE is O6 222, 24| 73 l-H 16.5 ſº ––3, 670 1 CHCl,
1,3,4,5-Tetramethyl-d-fructose-- - - - - - - - [6] C10H2006 236. 26|| 98–99 {-}; ºft .3 # ! . Mºh
O
1,3,4,6–Tetramethyl-d-fructose - - - - - - - - | [7] C10H2006 236. 26 Sirup-- {i}; (16°) ~~~~ ; Mºon
1,3,4,5-Tetraacetyl-d-fructose-- - - - - - -] [8] C14H20010 348. 30||131–132| — 91.6 –31, 900 3. CHCl3
2,3,4,5-Tetraacetyl-d-fructose - - - - - - - - [9] 141.120V / 10 348, 30|112 + 50.6 + 17, 600 3. CHCla
1,2,3,4,5-Pentaacetyl-o-d-fructose------| [10] '16H22O11 390. 34|122–123 + 47.4 + 18, 500 3| CHCla
1,2,3,4,5-Pentaacetyl-3-d-fructose - - ----| [11] 16 Ll22\J1 1 390. 34|108–109 — 120.9 –47, 200 5 CHCla
1,3,4,5,6-Pentaacetyl-d-fructose-- - - - - - -] [12] 1611, 22N-J 11 390. 34| 70 + 34.7 -|- 13, 500 8 CHCla
1,3,4,5-Tetrabenzoyl-d-fructose-- . . . . --| [13] C34H28O10 596. 57|174–175 – 164.9 –98, 400 4| CHCl3
1,3,4,5,6-Pentabenzoyl-d-fructose------| [13] 41 li B2\L’11 700. 67|124–125 + 40.9 +28, 700 3. CHCl3
2-Fluoro-1,3,4,5-tetraacetyl-3-d-fruc- | [14] C14H10O2 F 350. 29|112 – 90.4 –31, 700 6| CHCla
to Se.
2-Chloro-1,3,4,5-tetraacetyl-3-d-fruc- [15] C14H10O3Cl 366. 75|| 83 — 160.9 – 59, 000 2 CHCla
tose.
2-Hromo - 1,3,4,5-tetraacetyl-3-d-fruc- [14] C11H10O3. Br 411. 21 || 65 — 189.1 –77, 800 3. CHCl,
to SC. |
:
1,3,4,5-Tetraacetyl-6-chloro-d-fructose--| [15] C14H10O3Cl
Methyl ox-d-fructopyranoside---- - - - - - - [16] C7H1406
Methyl 3-d-fructopyranoside- - - - - - - - - - [17] C7H1406
Methyl 1,3,4,5-tetraacetyl-o'-d-fructo- | [16] C15H22O10
pyranoside.
Methyl 1,3,4,5-tetraacetyl-3-d-fructo- | [17] C15H22O10
pyranoside.
Methyl 1,3,4,5-tetrabenzoyl-3-d-fructo- | [13] C35H3000
pyranoside.
Methyl d-fructofuranoside-- - - - - - - - - - - [18] C;H1406
2,3-4,5-Diacetone-d-fructose - - - - - - - - - - - { [ º º C15H26O6
1,2-4,5-Diacetone-d-fructose - - - - - - ----- ſº C12H2006
366.
194.
194.
362.
362.
610.
194.
260.
260.
75|108 + 45.3 + 16, 600 2 CHCl2
18| 96–97 | +44 +8, 500 1| H2O
18||119—120 — 172.1 –33, 400 0| H2O
33||112 + 45.0 + 16, 300 1 CHCls
33| 75–76 — 124.6 –45, 100 8 CHCl3
59|113 — 171.3 — 104, 600 5| CHCls
18| 69 + 93.1 + 18, 100 2 H2O
28| 97 {#. (22°) —8, 560 3| H2O
–33.83 (22°) —8, 800 4| Acetone.
— 161.3 —41, 980 7| H2O
28||119–120K — 154 (23°) –40, 100 4| Acetone.
— 146.6 –38, 160 2 CHCla
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
REFERENCES
[1] C. S. Hudson and D. H. Brauns, J. Am. Chem. Soc. 38, 1222 (1916). [9] B. Helſerich and H. Bredereck, Liebigs Ann, Chem. 465, 166 (1928).
W. C. Vosburgh, J. Am. Chem. Soc. 42, 1696 (1920). [10] E. Pacsu and F. B. Cramer, J. Am. Chem. Soc. 57, 1945 (1935).
H. S. Isbell and W. W. Pigman, J. Research NBS 20, 773 (1938) RP1104. [11] C. S. Hudson and D. H. Brauns, J. Am. Chem. Soc. 37, 1283 (1915).
[2] C. G. Anderson, W. Charlton, W. N. Haworth, and V. S. Nicholson, J. Chem. Soc. [12] C. S. Hudson and D. H. Brauns, J. Am. Chem. Soc. 37, 2739 (1915).
1929, 1337. F. B. Cramer and E. PacSu, J. Am. Chem. Soc. 59, 1148 (1937).
[3] J. C. Irvine and A. Hynd, J. Chem. Soc. 95, 1220, (1909). [13] P. Brigl and R. Schinle, Ber, deut. chem. Ges. 66, 325 (1933).
C. F. All press, J. Chem. Soc. 1926, 1720. [14] D. H. Brauns, J. Am. Chem. Soc. 45, 2388 (1923).
[4] W. N. Haworth and A. Learner, J. Chem. Soc. 1928, 619. [15] D. H. Brauns, J. Am. Chem. Soc. 42, 1850 (1920).
J. C. Irvine and E. S. Steele, J. Chem. Soc. 117, 1474 (1920). [16] H. H. Schlubach and G. A. Schroeter, Ber. deut. chem. Ges. 61, 1216 (1928).
J. C. Irvine, E. S. Steele, M. I. Shannon, J. Chem. Soc. 121, 1060 (1922). [17] C. S. Hudson and D. H. Brauns, J. Am. Chem. Soc. 38, 1216 (1916).
[5] H. Hibbert, R. S. Tipson, and F. Brauns, Can. J. Research 4, 221 (1931). [18] C. B. Purves and C. S. Hudson, J. Am. Chem. Soc. 56, 708 (1934).
[6] W. N. Haworth and E. L. Hirst, J. Chem. Soc. 1926, 1858. [19] H. Ohle, Ber, deut. chem. Ges. 58,2577 (1925).
T. Purdie and D. M. Paul, J. Chem. Soc. 91, 289 (1907). E. Fischer, Ber. deut. chem. Ges. 28, 1165 (1895).
W. N. Haworth, E. L. Hirst, and A. Learner, J. Chem. Soc. 1927, 1040. [20] H. Ohle and I. Koller, Ber. deut. chem. Ges. 57, 1566 (1924).
E. S. Steele, J. Chem. Soc. 113, 257 (1918). H. Ohle, Ber. deut. chem. Ges. 60,1168 (1927).
J. C. Irvine and J. Patterson, J. Chem. Soc. 121, 2696 (1922). [21] J. C. Irvine and J. Patterson, J. Chem. Soc. 121, 2146 (1922).
[7] W. N. Haworth, J. Chem. Soc. 117, 199 (1920). J. C. Irvine and C. S. Garrett, J. Chern. Soc. 97, 1277 (1910).
W. N. Haworth, E. L. Hirst, and V. S. Nicholson, J. Chem. Soc. 1927, 1513. D. H. Brauns and H. L. Frush, BS J. Research 6, 449 (1931) RP287.
[8] D. H. Brauns, Proc. Roy. Acad. Amsterdam 10, 563 (1907–08).
C. S. Hudson and D. H. Brauns, J. Am. Chem. Soc. 37, 2738 (1915).
2 Value after 15 minutes.
E. Pacsu and F. V. Rich, J. Am. Chem. Soc. 55, 3022 (1933).
>
TABLE 1.48.—Optical rotation and melting point of certain sugars and sugar derivatives—Continued
OH. H. H OH
l-FU cose, CH3 C C C-—C— —-CHO
H OH OH. H.
• Molec- in or Con-
Substance º Formula ular Mºs [o]?' [M] 1261) - Solvent
weight D tration
oC
o'-l-Fucose- - - - - - - - - - - - - - - - - - - - - - - - - - - 1, 2, 3] Cº H12O5 164. 16| 1.45 – 152.6— — 75. 9 – 25, 100 4| H2O
l-Fucose phenylhydrazone - - - - - - - - - - - - - - 4, 5] C19H13O4N2 254. 28, 170–173 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ * - * *-* - * - - - - - - - - - - - - -
1,2,3,4-Tetraacetyl-o'-l-fucose--- - - - - - - - - [6] C14H2009 332. 30 92–93 – 120 (34°) –39, 800 2 CHC].
2,3,4,5-Tetraacetyl-l-fucose - - - - - - - - - - - - [6] C14H2000 332. 30, 166–167 + 40 (25°) + 13, 300 2 (CHCl2)2
Methyl ox-l-fucopyranoside--- - - - - - - - - - - 7] C; H 1405 178. 18|157. 5–158. 5| – 197. 4 –35, 100 5| H2O
Methyl 3-l-fucopyranoside -- - - - - - - - - - - . 7] CFH1405 178. 18 117–119 + 16. 0 +2, 900 1| H2O
Methyl 2,3,4-triacetyl-cy-l-fucopyranoside. [8] C15H26Os 304. 29 74 — 151 —45, 950 10 CHCla
Methyl 2,3,4-triacetyl-3-l-fucopyranoside. [8] 13.H200s 304. 29 99 ––7. 0 +2, 100 10 CHCI's
Monoacetone-l-fucose - - - - - - - - - - - - - - - - - [9] CoRI 16O5 204. 22 57 –62. 28 – 12, 700|_ _ _ _ _ _ _ _ _ _ _ — — — — -- - -
Diacetone-l-fucose - - - - - - - - - - - - - - - - - - - - 10] C19H2005 244, 28 37 +52. 2 (18°) -- 12, 750 - - - - - - - - None
l-Fuconic Y-lactone - - - - - - - - - - - - - - - - - - - [12] 6 Ll 10\L'5 162. 14|| 106–107 + 78. 3 + 12, 700 3| H2O
l-Fuconic amide - - - - - - - - - - - - - - - - - - - - - - 11] C6H13O5N 179. 17 180 –31. 1 –5, 570 2 H2O
l-Fuconic phonylhydrazide- - - - - - - - - - - - - [12] C19H18O3N2 270. 28, 203-204 |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1 These values are read at 20° C. except where the temperature is specified otherwise in parentheses.
REFERENCES
|} H. S. Isbell, heretofore unpublished measurement. [7] J. Minsaas, Rec. trav. chim. 51, 475 (1932).
2] B. Tollens and F. Rorive, Ber. deut. chem. Ges. 42, 2009 (1909); E. Votoček, Ber. [8] J. Minsaas, Rec. trav. chim. 56,623 (1937).
dout. chem. Ges. 37, 3859 (1904). [9] T. Tadokoro and Y. Nakamura, J. Biochem. 2, 461 (1923). -
[3] J. Minsaas, Rec. trav. chim. 50, 424 (1931). [10] K. Freudenberg and K. Raschig, Ber. deut. chem. Ges. 60, 1633 (1927).
[4] A. Günther and B. Tollens, Liebigs Ann. Chem: 271, 86 (1892).
; E. Votoček and B. Potmésil, Ber. deut, chem. Ges. 46, 3653 (1913).
[6] M. L. Wolfrom and J. A. Orsino, J. Am. Chem. Soc. 56, 985 (1934).
[11] E. P. Clark, Sci. Pap. BS 18, 527 (1922) S459.
[12] A. Muether and B. Tollens, Ber. deut. chem. Ges. 37, 306 (1904).
H
TA BI.E 14S.–Optical rotation and melting point of certain sugars and sugar derivatives—Continued
H OH OH. H.
d–GALA CTOSE CH3OH C——C C C CHO
OH. H. H OH
Molec- &
Refer- 4 'Arº tº Yº" Meltin 20 ! 2. Concen- * * *
Substance €In CeS Formula wº poin º [o]}} [M] tration Solvent
o C. g/100 ml
o-d-Galactose------------------------ [1, 2, 3, C6H12O6 180. 16| 167 + 150.7— --80.2 +27, 150 5| H2O
4, 5]
8-d-Galactose------- - - - - - - - - - - - - - - - - - [1, 2, 3, C6H12O6 180. 16|_ _ _ _ _ _ _ _ + 52.8— +80.2 +9, 510 4 H2O
4, 5]
d–Galactose o-tolylhydrazone ---------- 6, 7] C15H26O5Ns 284. 31, 176 -----------------------------|--------
2-Methyl-3-d-galactose--------- - - - - - - - [8] C7H13O6 194. 18, 147–149 –– 53.0 *— — — 82.6 |_ _ _ _ _ _ _ _ 5| H2O
6-Methyl-o-d-galactose--- - - - - - - - - - - - - [9] 7 Il 14V6 194. 18| 128 + 114 *— -- 77 [o] § - - - - - - - - 8| H2O
2,6-Dimethyl-3-d-galactose------------ [8] CsPI 16Og 208. 21 | 128–130 + 46.8 °– + 87.5 |_ _ _ _ _ _ _ _ 6| H2O
2,3,4-Trimethyl-o-d-galactose------ - - - - 10, 11 C9H18O6 222. 24 85 + 154. I — -- 122 (21°) |-|-34, 250 2| H2O
12, 13]
2,3,4,6–Tetramethyl-o'-d-galactose------ [14, 35 || C10H2006 236. 26|| 71 + 150.5— -- 1:19.9 (25°) |+35, 560|- - - - - - - - - - - - - - - -
2,3,4,6–Tetraacetyl-o'-d-galactose_-_ _ _ _ _ 15, 26 || C14H20010 348. 30| 133 + 144.4— + 90.7 +50, 300 1 CHCl3
2,3,4,6-Tetraacetyl-3-d-galactose------- | 16, 18]| C14H20010 348. 30| 112 +23.3 + 8, 120 5| CHCl3
2,3,5,6–Tetraacetyl-d-galactose--------- 17, 18]| C14H20010 348. 30| 71–73 — 17.8 –6, 200 5| CHC13
2,3,4,5,6-Pentaacetyl-d-galactose--- - - - - [19] C15H22O11 390. 34 121 –25 (26°) –9, 760 4| CHCl3
1,2,3,5,6-Pentaacetyl-3-d-galactose *----| [17] C16H22O11 390. 34| 87 -- 61.2 +23, 890 4| CHCl3
1,2,3,5,6-Pentaacetyl-o'-d-galactose *_ _ _ _ ] [20] C18H22O11 390, 34| 98 – 41.6 — 16, 240|_ _ _ _ _ _ _ _ CH Cla
1,2,3,4,6-Pentaacetyl-o-d-galactose-- - - - [21, 22]| C18H22O11 390. 34| 96 + 106.7 +41, 650 3| CHCl3
1,2,3,4,6-Pentaacetyl-3-d-galactose- - - - - 17, 21, 161122WCW 11 390, 34|| 142 +25 +9, 760|- - - - - - - - CHCl3
22]
1,2,3,4,5-Pentaacetyl-o-d-galactose_-_ _ _ [23] C18H22O11 390. 34|| 128 — 1 1.0 –4, 300 1 CHCl3
1,2,3,4,5-Pentaacetyl-3-d-galactose_-_ _ _ [23] 16 L L 22\-M 11 390. 34|| 101 —78.3 (18°) –30, 560 1 CHCl3
1, 1’,2,3,4,5,6-Heptaacetyl-d-galactose - -] [24] C20H28O14 492. 43| 106 +4.0 + 1, 970|_ _ _ _ _ _ _ _ CHCl,
1-Chloro-2,3,5,6-tetraacetyl-d-galactose- [17] C14H10O3Cl 366. 75' 67 – 77.1 –28, 280 6. CHCl3
:
TABLE 148.-Optical rotation and meltirg point of certain sugars and sugar derivatives–Continued
H OH OH. H.
CH2OH−—C—C—C–C–CHO
d-GALACTOSE
Oside.
OH H H OH
Molec- a . . . .
Substance º: Formula ular * |o]}} [M] º Solvent
weight
1-Chloro-2,3,4,6-tetraacetyl-o-d-galac- [25] C14H10O3Cl 366. 75 82–83 || --212.2 +77, 820 1 CHCl3
tose
1-Chloro-2,3,4,6-tetraacetyl-3-d-galac- [26] C14H10O3Cl 366. 75|| 93–94 || --5.8 (22°) +2, 130 1| CC1,
toSe
1-Bromo-2,3,4,6-tetraacetyl-a-d-galac- | [25, 27 || C14H10OgEr 411. 21 82–83 +236.4 +97, 210 9| Cah 6
to SG
1-Chloro-1',2,3,4,5,6-hexacetyl-d-galac- | [28] Cisłł25O)2Cl 468. 84 174–175 – 44 (27°) –20, 630 4| CHCl3
to SC
1-Bromo-1',2,3,4,5,6-hexacetyl-d-galac- | [28] Cisłł25O12 Br 513. 30, 179–181| –79 (27°) –40, 500 4 CHCl3
toSe
1-Iodo-1',2,3,4,5,6-hexaacetyl-d-galac- [28] Cisłł25O12 I 560. 30, 152–153 – 111 (25°) –62, 200 2 CHCla
tose
Methyl ox-d-galactopyranoside. H2O_ _ _ _ ] [4, 29, C7H16O7 212. 20 110 –– 179. 3 +38, 0.50 9| H2O
- 33]
Methyl 3-d-galactopyranoside- - - - - - - - - [4, 29, CFH 1406 194. 18, 178 0 0 10| H2O
30, 33]
Methyl 2,3,4,6-tetraacetyl-o-d-galacto- [32, 33 || C15H22O10 362. 33 86–87 | + 133.0 +48, 200 3. CHCl3
pyranoside
Methyl 2,3,4,6-tetraacetyl-3-d-galacto- || || 30, 33]| C15H23010 362. 33| 93–94 — 14.0 —5, O70 2 CHCl3
pyranoside
10thyl d-galactofuranoside----- - - - - - - - - [31] Cs H16Og 208. 21| 85–86 || – 102 –21, 200 1| H2O
Methyl 2, 3, 4, 5-tetraacetyl-o-d-gal- | [34] C15H22O10 362. 33| 108 + 17.0 +6, 160 1 CHCl3
actoseptanoside.
Methyl 2, 6-dimethyl-3-d-galactopyran- [8] CoPHisOg 222. 24. 45–47 – 23.3 (17°) — 5, 180 6. CHCls
:
Methyl 2, 3, 4-trimethyl-o'-d-galactopy- [13] C10H2006
ranoside.
Methyl 2, 3, 4, 6-tetramethyl-3-d-galac- | [11, 32, C11H22O6
topyranoside. 35]
Monoacetone-d-galactose- - - - - - - - - - - - - [36] C9H16O6
d–Galactonic acid “-- - - - - - - - - - - - - - - - - - [37, 38, C6H12O7
39, 40]
d–Galactonic Y-lactone- - - - - - - - - - - - - - - [37, 38, C6H10O6
40, 41]
d–Galactonic amide- - - - - - - - - - - - - - - - - - [42] C6H13O8.N
d–Galactonic phenylhydrazide- - - - - - - - - [40] C19H18O3N2
d–Galactal (talal) - - - - - - - - - - - - - - - - - - - - [43, 44]| C6H10O4
236.
250.
220.
196.
178.
195.
286.
146.
26
29
22
16
14
17
28
14
30
46–47
157
148
###;
110–112
176
203
100
+ 198.4 (25°)
––20.7
— 10.9
— 13.6
— 77.4
––31.8
+ 10.4
+46, 870
+ 5, 100
–2, 400
–2, 670
— 13, 790
+6, 210
+2, 980
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
* Rotation 5 minutes after Solution.
3 The alpha-beta nomenclature is opposite to that of Hudson. See footnote 39.
4 A hydrate (C12H24O14-H2O mp 140 to 142°C.) crystallizes from aqueous Solution.
H. S. Isbell and W. W. Pigman, J. Research NBS 18, 141 (1937) RP969.
[2] C. N. Riiber and J. Minsaas, Ber. deut. chem. Ges. 59, 2266 (1926).
[3] T. M. Lowry and G. F. Smith, J. Phys. Chem. 33, 9 (1929).
[4] C. N . Riiber, J. MinsaaS and R. T. Lyche, J. Chem. Soc. 1929, 2173.
... W.
P.
ſ
}
[5] N Sørensen, Kgl. Norske Videnskab. Selskabs, Skrifter, No. 2 (1937).
[6] A van der Haar, Rec. trav. chim. 37, 108, 251 (1917).
|7 T. Sah and C. Tseu, Chem. Abst. 30, 7105 (1936).
IP.
J.
K. Freudenberg and K. Smeykal, Ber, deut. chem. Ges. 59, 100 (1926).
0] M. Onuki, Chem. Abst. 27, 2676 (1933).
§ W. Oldham and D. J. Bell, J. Am. Chem. Soc. 60, 323 (1938).
[1
[11] S. W. Challinor, W. N. Haworth, and E. L. Hirst, J. Chem. Soc. 1931, 258.
[12] M. Onuki, Sci., Pap. Inst. Phys. Chem. Research (Tokyo) 20, 234 (1933); Chem.
Abst. 28, 113 (1934). e
13] P. A. Levene, R. S. Tipson, and L. C. Kreider, Science 86, 332 (1937).
14] B. C. Hendricks and R. Rundle, J. Am. Chem. Soc. 60, 2563 (1938).
15] Zd. H. Skraup and R. Kremann, Monatsh. 22, 1045 (1901).
C. S. Hudson and E. Yanovsky, J. Am. Chem. Soc. 38, 1869 (1916).
Z. Unna, Inaugural Dissertation, p. 22 (Berlin, 1911).
C. S. Hudson and J. M. Johnson, J. Am. Chem. Soc. 38, 1223 (1916).
8) J. Compton and M. L. Wolfrom, J. Am. Chem. Soc. 56, 1160 (1934).
9] M. L. Wolfrom, J. Am. Chem. Soc. 52, 2464 (1930).
[20] C. S. Hudson, J. Am. Chem. Soc. 37, 1591 (1915).
[21] E. Erwig and W. Koenigs, Ber, deut. chem. Ges. 22, 2207 (1889).
|22 C. S. Hudson and H. O. Parker, J. Am. Chem. Soc. 37, 1589 (1915).
[23] F. Micheel and F. Suckfüll, Liebigs Ann. Chem. 502, 85 (1933).
9
3
[14
[15
[16
|
|l
| 1
REFERENCES
[24] N. W. Pirie, Biochem: J. 30, 374 (1936).
[25] E. Fischer and E. F. Armstrong, Ber. deut. chem. Ges. 34, 2894 (1901); 35,833 (1902)
Zd. H. Skraup and R. Kremann, Monatsh. 22, 379 (1901).
26] H. H. Schlubach and R. Gilbert, Ber. deut. chem. Ges. 63, 2292 (1930).
27] H. Ohle, W. Marecek, and W. Bourjau, Ber. deut. chem. Ges. 62,849 (1929).
28] M. L. Wolfrom, J. Am. Chem. Soc. 57, 2498 (1935).
29] E. Fischer, Ber. deut. chem. Ges. 28, 1155 (1895); E. Fischer and L. Beensch, Ber.
deut. chem. ges. 27, 2478 (1894).
J.
N
J.
P
T
| W. Koenigs and E. Knorr, Ber. deut. chem. Ges. 34, 979 (1901).
| J. W. Green and E. PacSu, J. Am. Chem. Soc. 59, 1208 (1937).
| F. Micheel and O. Littmann, Liebigs Ann. Chem. 466, 115 (1928).
| J. K. Dale and C. S. Hudson, J. Am. Chem. Soc. 52, 2534 (1930).
| F. Micheel and F. Suckfüll, Liebigs Ann. Chem. 507, 138 (1933).
35] H. H. Schlubach and K. Moog, Ber. deut. chem. Ges. 56, 1957 (1923).
| P. A. Levene and G. M. Meyer, J. Biol. Chem, 64,473 (1925),
| H. S. Isbell and H. L. Frush, BS J. Research 11,649 (1933) RP613.
| L. Barth and H. Hlasiwetz, Liebigs Ann. Chem. 122, 96 (1862).
39] J. M. Brackenbury and F. W. Upson, J. Am. Chem. Soc. 55, 2512 (1933).
U. W. Nef, Liebigs Ann. Chem. 403, 273 (1914).
. K. Richtmyer, R. M. Hann and C. S. Hudson, J. Am. Chem. Soc. 61, 340 (1939);
O. Ruff and A. Franz, Ber. 35,948 (1902).
W. E. Glattfeld and D. Macmillan, J. Am. Chem. Soc. 56, 2481 (1934).
. A. Levene and R. S. Tipson, J. Biol. Chem. 93, 631 (1931).
. Komada, Bul. Chem. Soc. Japan 7, 211 (1932).
§
TABLE 148,-Optical rotation and melting point of certain sugars and sugar derivatives—Continued
H OH OH. H. H
d-or-GALAHEPTOSE * : CH2OH C C C C C CHO
OH H H OH OH
Molec- & ~!
Refer- Melting on 1 (JOI) Cen-
Substance Formula ular in 4- [o]}} [M] se Solvent
€I) CeS weight || point tration
oC J/100 ml
o:-d-o-Galaheptose.H2O * - * * * * * * * * * *-* *-* - - - - - * * * ſ 1, 2] C7H16Os 228. 20 77–78 — 25.2— — 14.0 - 5, 750 H2O
d-of-Galaheptose phenylhydrazone - - - - - - - - - - - [3] C18H2006N2 300. 31|| 195-205|- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
d–Galaheptose phenylosazone---------------- [3] 10H24O5N1 388. 42 224 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ !-- - - - - - - - - - - - - - -
2,3,4,5,6,7-Hexaacetyl-d-o-galaheptose-------- [4] 19.Ll 26V-J 13 462. 40. 173–174 – 27.0 + 12, 500 1 CHCl3
1, 1’,2,3,4,5,6,7-Octaacetyl-d-a-galaheptose- - - -] [4] 23H32O16 564. 49| 112 + 29.8 + 16, 800 2| CHCl3
Methyl ox-d-a-galaheptopyranoside-- - - - - - - - - [2] C8H16O7 224, 21| 132 — 70.2 — 15, 700 3| H2O
Methyl 3-d-of-galaheptopyranoside--- - - - - - - - - [5] CgFIGO, 224, 21|| Sirup --| + 74 |_ _ _ _ _ _ _ _ 3| H2O
Mº yl pentaacetyl-o'-d-o-galaheptopyrano- | [2] C15H26O12 434, 39| 108 —20.4 —8, 860 2 CHCl3
S1Clé.
Methyl pentaacetyl-3-d-a-galaheptopyrano- | [5] C15H26O12 434. 39| 171–173 –– 77.6 +33, 700 4| CHC13
side.
Ethyl ox-d-o-galaheptopyranoside - - - - - - ** = <-2 = ** - [2] CoPH16O7 238. 24| 138 — 65.4 — 15, 600 2| H2O
Ethyl pentaacetyl-o-d-o-galaheptopyranoside--| [2] C19H28O12 448. 42| 92 — 24.9 — 11, 200 4| CHCla
d-o-Galaheptonic acid -- - - - - - - - - - - - - - - - - - - - - [2, 6, 7 || C. HiſOs 226. 18 143–147| + 2.5 °– — 28. 3 |_ _ _ _ _ _ _ _ 1 2O
d-o-Galaheptonic Y-lactone - - - - - - - - - - - - - - - - - [2, 3, 6]| C7H12O7 208. 17| 151 — 52.3 — 10, 900|- - - - - - - - 2
d-o-Galaheptonic amide-------------------- [8] C-H15O.N 225. 20. 206 + 14.3 + 3, 220 1 2
d-o-Galaheptonic phenylbydrazide-- - - - - - - - - - [3, 9] C15H26O7 N2 316, 31|| 226 +8.5(80°) +2, 700 1| H2O
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
* Isbell's nomenclature used.
8 At 5 minutes and 10 days.
§
[1] H. S. Isbell, J. Research N BS 18, 505 (1937) R P990.
[2] R. M. Hann, A. T. Merrill, and C. S. Hudson, J. Am. Chem. Soc. 57, 2100 (1935).
[3] E. Fischer, Liebigs Ann. Chem. 288, 139 (1895).
É R. M. Hann and C. S. Hudson, J. Am. Chem. Soc. 59, 1898 (1937).
[5] H. S. Isbell and H. L. Frush, J. Research NBS 24, 125 (1940) RP1274.
[6] H. Kiliani, Ber. deut. chem. Ges. 21, 915 (1888); 55, 493 (1922).
ſ: L. Maquenne, Compt. rend. 106, 286 (1888).
[8] C. S. Hudson and S. Komatsu, J. Am. Chem. Soc. 41, 1141 (1919).
[9] C. S. Hudson, J. Am. Chem. Soc. 39, 462 (1917).
H OH OH. H. OH
d-6-GALA HEPTOSE * : CH3OH C C C C C CHO
OH H H OH H
Molec- *
ºt Refer- Melting »n 1 Concen- r
Substance €1) CeS Formula ular point [o]}} [M] tration Solvent
weight
oC g/100 ml
B-d-3-Galaheptose- - - - - - - - - - - - - - - - - - - - - - - - - [1, 2, 3]| CFH 1407 210. 18, 197 — 19.2— —54.1 — 4, 040 4| H2O
Hexaacetyl-o-d-3-galaheptose- - - - - - - - - - - - - - - [3] C19H26O13 462. 40|| 100–101 | – 55.8 — 25, 800 2| CHCla
Hexaacetyl-3-d-3-galaheptose----- - - - - - - - - - - - [3] 1911 26\ W 13 462. 40|| 151–152 + 30.2 + 14, 000 2| CHCl,
Methyl ox-d-g-galaheptopyranoside -- - - - - - - - - - [4] C8H16O7 224, 21 | 154–155| — 108 –24, 200 4| H2O
Methyl 3-d-3-galaheptopyranoside - - - - - - - - - - - [3] Cs.H16O7 224, 21 | 182–183| + 36.0 + 8, 100 2 H2O
Methyl pentaacetyl-3-d-6-galaheptopyranoside [3] C18H26O12 434. 39' 122–123| + 51.8 +22, 500 2| CHCl3
d-8-Galaheptonic amide- - - - - - - - - - - - - - - - - - - - [3] C; HisO.N 225. 20. 1 70–171 – 20 –4, 500 1| H2O
d-8-Galaheptonic phenylhydrazide- - - - - - - - - - - [3] C15H26O7.Ng 316. 31 | 189–190 – 7.8 –2, 500|_ _ _ _ _ _ _ _ H2O
REFERENCES
| These values are read at 20° C except where the temperature is specified otherwise in parentheses.
3 Isbell’s nomenclature used.
REFERENCES
| E. Fischer, Liebigs Ann. Chem. 288, 154 (1895).
|l
[2] H. S. Isbell, J. Research NBS 18, 505 (1937) R P990.
[3] R. Hann and C. S. Hudson, J. Am. Chem. Soc. 59, 548 (1937).
[4] H. S. Isbell and H. L. Frush, J. Research N BS 24, 125 (1940) RP1274.
§
TABLE 14S.—Optical rotation and melting point of certain sugars and sugar derivatives–Continued
GENTIOBIOSE (6-(8-d-Glucopyranosido)-d-glucose)
Substance
Refer-
€1) CGS
o:-Gentiobiose.2CH3OH -- - - - - - - - - - - - - - - -
Gentiobiose phenylosazone.----- - - - - - - - - -
Heptaacetyl-o-gentiobiose - - - - - - - - - - - - - -
Octaacetyl-o-gentiobiose--------- - - - - - - -
Octaacetyl-3-gentiobiose---------------- |
1-Fluoro-heptaacetyl-o-gentiobiose--- - - - -
1-Chloro-heptaacetyl-o-gentiobiose---- - - -
1-Bromo-heptaacetyl-o-gentiobiose---- - - -
1-IOdo-heptaacetyl-o-gentiobiose------ - - -
Methyl o-gentiobioside *_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Methyl 3-gentiobioside-------- - - - - - - - - -
Methyl heptaacetyl-o-gentiobioside------
Methyl heptaacetyl-3-gentiobioside- - - - - -
Gentiobial----------------------------
Molec-
Melt-
Formula ular ing [o]}} I [M]
weight | point
oC
C14H 30O13 406. 38 85–-86 +21.4—3. + 8.7 +8, 700
C24 H3300 NA 520. 53| 170–173| – 74.8 –38, 940
2811 38WCW 19 678. 59| 189 + 52.4 +35, 600
281138V 19 678, 59| 193 —5.3 –3, 600
C26H35017F 638. 54, 168–169| ––43.8 +28, 000
C26H35017Cl 655. 00. 148 --80.5 +52, 700
C26H35017 Br 699. 46|| 144 -- 101.1 +70, 700
C26H35017.I 746. 46|| 134 d. + 126.1 +94, 100
& 13 L124 V11 356. 32| 120 +65.5 (18°) +23, 340
13H24O11 356, 32| 98 — 36.0 — 12, 800
27.1138V 18 650. 58| 96 –– 64.5 +42, 000
C27H3301s 650. 58| 82 — 18.9 — 12, 300
12 1.120V /9 308. 28, 194 —5.8 (23°) — 1, 790
Concen-
tration
g/100 ml
r
J.
* =º sº. º. -- * * *-
|
:
Solvent
H2O
Pyridine-H
EtOH
Pyridine
CHCla
CHC13
CHCl3
CHCla
CHCla
CHC13
H
H2O
CHC13
CHCla
H2O
! These values are read at 20° C except where the temperature is specified otherwise in parentheses.
? At 3 minutes and 22°C
3 Crystallizes with one molecule of C2H5OH. Constants are on alcohol-free substance.
REFERENCES
[1] H. S. Isbell, heretofore unpublished measurement.
G. Zemplén, Z. physiol. Chem. 85, 399 (1913).
7] I). H. Brauns, J. Am. Chem. Soc. 49, 3170 (1927).
i8] B. Helferich and J. Becker, i.iebigs Ann. Chem. 440, 1 (1924).
E. Bourquelot, H. Hérissey, and J. Coirre, Compt. rend. 157, 732 (1913).
E. Bourquelot and H. Hérissey, Ann. chim. phys. 27 [7], 397 (1902).
G. Zemplén, Z. physiol. Chem. 85, 399 (1913).
[2] B. Helferich and W. Klein, Liebigs Ann. Chem. 450, 219 (1926).
[3 §: Zemplén, Ber. deut; chem. Ges. 48, 233 (1915).
. Helferich, K. Bäuerlein, and F. Wiegand, Liebigs Ann. Chem. 447, 27 (1926).
| M. Bergmann and W. Freudenberg, Ber. deut. chem. Ges. 62, 2783 (1929).
C. S. Hudson and J. M. Johnson, J. Am. Chem. Soc. 39, 1272 (1917).
B. Helferich, W. Klein, and W. Schäfer, Liebigs Ann. Chem. 447, 19 (1926).
§
TABLE 148.-Optical rotation and melling point of certain sugars and sugar derivatives–Continued
H H OH H H
d-o-GLUCOHEPTOSE CH3OH C C C——C——C—CHO
OH. O.H. H. OH OH
Molec- e
Substance º: Formula Alar * [a]?' [M] º Solvent
weight
oC g/100 ml
8-d-o'-Glucoheptose- - - - - - - - - - - - - - - - - [1, 2, 3, C, H13O; 210. 18, 193 — 28.7— — 20.2 –6, 030 4 H2O.
4]
d-o-Glucoheptose 3-naphthylhydra- [2] C17H22O6N2 350. 36, 182 – 13 (17°) –4, w 1. Pyridine.
ZOI) e.
d-Glucoheptose phenylosazone-- - - - - - - [3, 4, C10H24O5N1 388. 42 194–195 — 1–5 ––35.6 –390. 2 Pº --
4-Methyl-d-o'-glucoheptose--- - - - - - - - - [6] Cs.H16O7 224, 21 185 — 26.0— — 15.0 —5, 830 1| H2O.
Pentamethyl-o-d-a-glucoheptose-- - - - - [6] C19H24O7 280. 31|| 80 –8.0— — 44.5 – 2, 240 1| H2O.
Pentamethyl-3-d-o'-glucoheptose-- - - - - [7] 12 L124V7 280, 31|| 84 —62.5— — 42.5 (18°)|– 17, 520 1 H2O.
Hexaacetyl-o-d-o'-glucoheptose- - - - - - - [3, 8] C19H26O13 462. 40 164 + 87.0 +40, 230 - - - - - - - - CHCl3
Hexaacetyl-3-d-o'-glucoheptose- - - - - - - [2, 3, 19H26O13 462. 40| 135 +4.8 +2, 220 - - - - - - - - CHCl2
8]
1-Chloro-pentaacetyl-o'-d-o'-glucohep- | [7] C17H23C)11Cl 438. 81| 97 ––95 +41, 690 1 CHCl,
tose.
1-Chloro-pentaacetyl-6-d-o'-glucohep- | [7] C17H33O11Cl 438. 81| 125 –– 11 + 4, 830 1 CHC13
tose.
1-Bromo-pentaacetyl-o'-d-a-glucohep- [2, 7] | C17H33O11 Br 483. 27 110 + 156 +75, 390 1| CHCla
tose.
Methyl-o'-d-o'-glucoheptopyranoside---| [9] C8H16O7 224, 21 106–107 –– 111.5 +25,000 4| H2O.
Methyl-8-d-o'-glucoheptopyranoside- - -] [10] 811 16V7 224, 21 168–170 — 74. 9 — 16, 790 10| H2O.
Methyl pentaacetyl-o'-d-a-glucohepto- | [7] C18H26O12 434, 39| 169 + 91 +39, 530 1 CHCl3
side.” -
Methyl pentaacetyl-o-d-a-glucohepto- | [9] Cisłł25O12 434. 39 174–175 –– 107.4 +46, 650 4| CHCl3
Side.”
§
TABLE 1.48.-Optical rotation and melting point of certain sugars and sugar derivatives---Continued
H H OH H H
d-a-GLUCOHEPTOSE CH2OH−—C—C——C—— C–C–CHO
OH OH H OH OH
Molec- *
Refer- { Melting 201 A Concen- -
Substance eI) CeS Formula wº t point [o]}} [M] tration Solvent
Methyl pentaacetyl-3-d-a-glucohepto- | [7] C18H16O12 434. 39 150 — 16 –6, 950 1 CHCl2.
side.
1,2-[3,4,6,7–Tetraacetyl-d-o'-glucohep- | [7] Cish 26O12 434. 39 112 + 43 (17°) + 18, 680 1 CHC13.
tose] methyl Orthoacetate.
d-o-Glucoheptonic acid-- - - - - - - - - - - - - [11] C; H 140s 226. 18|- - - - - - - - — 8.7— — 42.4 — 1, 970 2 H2O.
d-o'-Glucoheptonic Y-lactone – - - - - - - - [3, }} C; H1907 208. 17| 145–148 — 56— — 50 – 11, 660 2 H2O.
12
d-o'-Glucoheptonic amide - - - - - - - - - - - - [13, C; H15O1 N 225. 20, 134 + 10.6 + 2, 390 1| H2O.
14]
d-o-Glucoheptonic phenylhydrazide - - -] [15, C15H26O; Nº. 316. 31|| 171–172 –- 9.3 +2, 940 4| H2O.
16]
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
2 The difference in structure of these two compounds has not been determined.
REFERENCES
H. S. Isbell, J. Research N BS 18, 505 (1937) RP990.
| E. Glaser and N. Zuckermann, Z. physiol, Chem. 166, 103; 167, 37 (1927).
E. Fischer, Liebigs Ann. Chem. 270, 64 (1892).
L. H. Philippe, Ann. chim. [8] 26, 322 (1912).
| W. C. Austin, J. Am. Chem. Soc. 52, 2106 (1930).
P. A. Levene, A. Raymond, and R. Dillon, J. Biol. Chem. 96, 449 (1932).
| W. N. Haworth, E. L. Hirst, and M. Stacey, J. Chem. Soc. 1931, 2864.
C. S. Hudson and E. Yanovsky, J. Am. Chem. Soc. 38, 1575 (1916).
H. S. Isbell and H. L. Frush, J. Research NBS 24, 125 (1940) RP1274.
j E. Fischer, Ber. deut. chem. Ges. 28, 1156 (1895).
P. A. Levene and G. Meyer, J. Biol. Chem. 60, 173 (1924).
H. Kiliani, Ber, deut. chem. Ges. 19, 770 (1886).
3] G. Zemplén and D. Kiss, Ber. deut. chem. Ges. 60, 169 (1927).
C. S. Hudson and S. Komatsu, J. Am. Chem. Soc. 41, 1141 (1919).
| E. Fischer and F. Passmore, Ber. deut. Chem. Ges. 22, 2732 (1889).
C. S. Hudson, J. Am. Chem. Soc. 39, 462 (1917).
§
H H OH H OH
d-6-GLUCOHEPTOSE CH2OH-——C—C—C—C—C CHO
OH OH. H. OH H
----- - - - ---------- Mol
- * OleC- º
Substance . Formula ular * [a]}'' [M] ‘. Solvent
weight
oC g/100 ml
d-6-Glucoheptose---------------- - - - - - - [ 1, 2] C7H1407 210. 19 121 — 0.1— —0.1 2 –– 20 5| H2O
d-6-Glucoheptose phenylhydrazone.------- [3 C15H26O6N2 300. 31, 192 |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hexaacetyl-d-3-glucoheptose-------- - - - - -] [4] C19H26O13 462. 40|| 136 — 9.1 – 4, 210 4| CHCl3
d-8-Glucoheptonic acid - - - - - - - - - - - - - - - - - [3, 5, 6]| C7H1408 226. 18 134–135|| -- 1.3— — 35.5 + 300 3| H2O
d-6-Glucoheptonic Y-lactone_--_ _ _ _ _ _ _ _ _ _ [3, 7] C7H12O7 208. 17| 161–162 – 82.1— — 50.13 – 17, 100 10| H2O
d-6-Glucoheptonic amide------- - - - - - - - - -] [8] CTPI is Or N 225, 20 158 — 30.2 –6, 800 5| H2O
d-8-Glucoheptonic phenylhydrazide- - - - - - [3] C15H26O7.Ng 316. 31|| 150–152|- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
* Complex mutarotation.
3 Measured at 23°C after heating.
[1] H. S. Isbell, J. Research NBS 18, 505 (1937) RP990.
[2] H. S. Isbell, J. Am. Chem. Soc. 56, 2789 (1934).
[3] E. Fischer, Liebigs Ann. Chem. 270, 83 (1892).
[4] H. S. Isbell, heretofore unpublished measurement.
[5] H. Kiliani, Ber. deut. chem. Ges. 58, 2353 (1925).
[6] K. Rehorst, Liebigs Ann. Chem. 503, 143 (1933).
[7] L. Philippe, Ann. chim, phys. 26, [8] 328 (1912).
[8] C. S. Hudson and S. Komatsu, J. Am. Chem. Soc. 41, 1141 (1919).
REFERENCES
§
TABLE 148,-Optical rotation and melting point of certain sugars and sugar derivatives—Continued
H H OH. H.
d–GLUCOMETHYLOSE CH3 C C C C CHO
OH. O.H. H. OH
Molec- te
º Refer- Tor Melting 1 !\ Concen-
Substance €1) CéS Formula wºit point [o]}} [M] tra,tion
o () g/100 ml
o-d-Glucomethylose--- - - - - - - - - - - - - - - - - - - - 1, 2, 4 || Cah is O5 164. 16 139–140 + 73.3— + 29.7|+ 12, 030 8
d-Glucomethylose phenylosazone.-------- - - - 1, 2, 4 || C18H22O3N4 342. 40, 185–187| — 94.3% –32, 290 2
Methyl ox-d-glucomethylopyranoside------ - - [3] C7H1405 178. 18, 98–99 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ --- - - - - - - - - - - - - - - - --
Methyl 3-d-glucomethylopyranoside-------- [4] C;H1405 178. 18| 131–132 — 55.1 —9, 820 9
Methyl triacetyl-o'-d-glucomethylopyrano- | [3] C15H26Os 304. 29| 75 + 159.2 +48, 440 13
side.
Methyl triacetyl-3-d-glucomethylopyrano- | [4, 5] | C18H2008 304. 29| 94–96 || – 20.3 — 6, 180 8
side.
1-Bromo-2,3,4-triacetyl-o-d-glucomethylose - [5] C12H17OHPr 353. 17 135–136 -– 228.4 (17°) |-|-80, 660 1
d-Glucomethylonic Y-lactone- - - - - - - - - - - - - - [4] 6LL 10V5 162. 14 151—152 + 66.9— + 5.3 |+ 10, 850 8
d-Glucomethylonic phenylhydrazide-------- [4] C12H18O3N2 270. 28, 152 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
| These values are read at 20° C except where the temperature is specified otherwise in parentheses.
* Measured with white light.
§
REFERENCES
[1] E. Votoček, Ber. deut. chem. Ges. 44, 819 (1911).
[2] E. Votoček, Ber. deut. chem. Ges. 43,476 (1910).
K. Freudenberg and K. Raschig, Ber. deut. chem. Ges. 62, 373 (1929). *
[3] B. Helferich, W. Klein, W. Schäfer, Ber. deut. chem. Ges. 59, 79 (1926); Liebigs Ann. Chem. 447, 19 (1926).
[4] E. Fischer and K. Zach, Ber. deut. chem. Ges. 45, 3761 (1912).
[5] F. Micheel, Ber. deut. chem. Ges. 63, 347, 755 (1930).
OH
GLUCOSAMINE CH2OH C C C C CHO
OH. O.H. H. NH2
Molec- º
>. Refer- * Melting 20 1 f Concen- -
Substance €1] CéS Formula wº t po int [o]% [M] tration Solvent
o C. g/100 ml
Pentaacetyl ox-glucosamine - - - - - - - - - - - - - - - - - - - - [1] C15H23010N 389. 35. 139–140 + 93.5 |-|-36, 400 5| CHCla
Pentaacetyl 3-glucosamine-------- - - - - - - - - - - - - - - [1] C15H23C10N 389. 35| 189 + 1.2 +470 4| CHCl3
* These Values are read at 20° C except where the temperature is specified otherwise in parentheses.
REFERENCES
[1] C. S. Hudson and J. K. Dale, J. Am. Chem. Soc. 38, 1431 (1916).
§
TABLE 148.—Optical rotation and melting point of certain sugars and sugar derivatives—Continued
H H OH H
d–GLUCOSE CH2OH C C C——C——CHO
OH OH H OH
MO1 -
| Refer- O16CUl- Melting 20 ! A. Concen- y
Substance €Il CGS Formula wº point [o]*; [M] tration Solvent
oC g/100 ml
o-d-Glucose-- - - - - - - - - - - - - - - - - - [1, É 3, C6H12O6 180. 16. 146 + 112.2— —H 52.7 +20, 210 4 H2O
4, 5
o-d-Glucose.H2O -, *-* -> *-* - - - - - - - - - - -- [2, 4] C6H1407 198. 17 83 + 102.0— — — 47.9% |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ H2O
8-d-Glucose -- - - - - - - - - - - - - - - - - - 1, 4,6]| C6H12O6 180. 16. 148–150 -- 18.7— + 52.7 +3, 370 4 H2O
d-Glucose o-phenylhydrazone - - -] [7, 8] C12H18O3N2 270. 28, 159–160 — 87— — 50 (approx.) | – 23, 510 4 H2O
d-Glucose 3-phenylhydrazone.---| || 7,8] C12H18O3N2 270. 28. 140–142 – 5–2 – 50 (approx.) — 1, 300 4 H2O
d-Glucose phenylosazone- - - - - - - [9] Cish 220, Na 358. 39| 208 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -- - - - -- * * * - - - -
2-Methyl-8-d-glucose--- - - - - - - - - ſ #. # C7H1406 194. 18 157–158 ––23.5 3–5 –– 65.3 |_ _ _ _ _ _ _ _ _ 2 H2O
13, 1
3-Methyl-o'-d-glucose--- - - - - - - - - 15, 16]| CH1406 194. 18, 160–161 -- 104.3— — — 55.3 +20, 250 1. H2O
3-Methyl-3-d-glucose--- - - - - - - - - [16] C7H1406 194. 18 130–132 + 31.9— -- 55.1 +6, 190 1 H2O
4-Methyl-d-glucose - - - - - - - - - - - - }} 12, C7H1406 194, 18| Sirup - - ? — -- 53 |- - - - - - - - - 2 H2O
1
5-Methyl-d-glucose- - - - - - - - - - - - [18] C;H1406 194. 18|_ _ _do - || – 10.6 |_ _ _ _ _ _ _ _ _ 2 Ab. EtOH
6-Methyl-o'-d-glucose--- - - - - - - - - % 19, Człł 14O6 194. 18. 145 + 110— -- 55 (16°) +21, 360 3 | H2O
20
2,3-Dimethyl-o-d-glucose - - - - - - | [ 16, 21]| CsPI 16O6 208. 21| 85–87 ––81.93— — — 48.3 + 17, 060 1. Acetone
2,3-Dimethyl-3-d-glucose - - - - - - - [16, 21]| CsPI1606 208. 21| 108–110 –– 5.9— -i- 50.9 + 1, 230 4 DO.
5,6-Dimethyl-d-glucose - - - - - - - - - [22] Cs H16O6 208. 21. Sirup- - - -4.0 (32°) |_ _ _ _ _ _ _ _ _ 2 H2O
3,6-Dimethyl-o-d-glucose - - - - - - - [23] C8H16O6 208. 21 113–116 -- 102.5— + 61.5 (18°) + 21, 340 3 H2O
2,3,4-Trimethyl-d-glucose- - - - - - - [24, 25] Coh 18O6 222, 24 Sirup_ _ | +50 (approx.) |_ _ _ _ _ _ _ _ _ 4 H2O
2,3,6–Trimethyl-o-d-glucose - - - - - [26, 27, Coh 18Og 222. 24|ſ 122–123 – 90.2— — — 70.5 - - - ' -- ~ -- - - - - - H2O
28, 29] 92–93
2,4,6-Trimethyl-o'-d-glucose - - - - - [30] Coh is O6 222. 24. 123 ––89.7— — — 71.9 + 19, 930. 2 H2O
§
Trimethyl-d-glucose - - - - - -
Trimethyl-d-glucose- - - - - - -
–Tetramethyl-o'-d-glucose-
–Tetramethyl-3-d-glucose-
–Tetramethyl-3-d-glucose-
.4,6–
• J, U-
5 *-* } +y
3.4,6
3.5,6
2,3,4
2,3,4,6
2,3,5,6
3,4,6-
2,3,4
2.3.4
1,2,3
1,2,3
2,3,4
1,2,3
–Triacetyl-o'-d-glucose- - - - - -
–Tetraacetyl-o'-d-glucose - -
–Tetraacetyl-3-d-glucose - -
,3,4-Tetraacetyl-3-d-glucose - -
,3,6–Tetraacetyl-3-d-glucose - -
,3,4,5,6-Pentaacetyl-d-glucose - -
,2,3,4,6- Pentaacetyl- or - d -glu-
COSe
1,2,3,4,6- Pentaacetyl-8- d -glu -
COSé
1, 1’,2,3,4,5,6-Heptaacetyl-d-glu-
COSé
6
6
,6
,3,4,6
4
6
5
y y
y
1-Chloro-1,2,3,4,5,6-hexaacetyl-
d-glucose
1-Bromo-1,2,3,4,5,6-hexaacetyl-
d-glucose
1-Fluoro-2,3,4,6-tetraacetyl-o-d-
glucose.
1-Chloro-2,3,4,6-tetraacetyl-o-d-
glucose.
1-Bromo-2,3,4,6-tetraacetyl-o-d-
glucose.
1-Iodo-2,3,4,6-tetraacetyl – o – d –
glucose.
1-Fluoro-2,3,4,6-tetraacetyl-3-d-
glucose.
1-Chloro-2,3,4,6-tetraacetyl-3-d-
glucose.
1-Nitro-2,3,4,6-tetraacetyl-o'- d -
glucose.
[31]
[15, 16]
[32, 34]
[32]
[15, 33,
35, 36]
[37, 38]
[39, 40.]
41]
[58, 62,
63]
}[64]
[65, 66]
[59]
C9H18O3
CoEI18O6
C10H2006
C10H2006
C10H
2006
C12H18O3
C14H20010
C14H20010
C14H20010
C14H20010
C15H22O11
C16H22O11
C16H22O11
C20H28O14
C18H25012Cl
C18H25012 Br
C14H10OgE
C14H10O3Cl
C14H10OgEr
C14H10Ogſ
C14H10O3F
C14H10O3Cl.
C14H10O11N
222.
222.
236.
236.
236.
306.
348.
348.
348.
348.
390.
390.
390.
492.
468.
513.
350.
366.
411.
458.
350.
366.
377.
24
26
29
75
30
50(Impure)
Sirup__
113–115
107–108
118–119
105–106
129–130
108
75–76
88–89
108–109
85–87
98
99-00
150–151.
|
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
2 Calculated from the values for the anhydrous form.
3 Rotation after 5 minutes
+71 [o] §
— 25.9
+ 100.8— --83.3
+ 73.1— + 83.1
– 28.8
+ 139.6 (18°)
–– 138.9
+2.2— --82.7
—- 12.1
— 30.2
— 4.8 (24°)
+ 101.6
+3.8
+8 (25°)
–49 (25°)
–79 (25°)
+ 90.1
+ 166. 1
+ 197.8
––237.4
+ 19.5 (18°)
––21.9 (18°)
— 13.0— + 81.2 (17°)
+ 149.3 (?) (18°)
+42, 760
+48, 400
––770
+4, 200
— 10, 520
— 1, 870
+39, 700
+ 1, 480
+3, 900
—23, 000
–40, 500
+31, 600
+60, 900
+81, 300
+ 108,800
+6, 800
+7, 700
–4, 770
+56, 330
i
2
;
Ethyl acetate
CHCl3
EtOH
CHC13
H2O
CHCla
CHCla
CHC13
CHCl3
CHCls
CHCls
CHCls
CHCla
CHCla
CHCl3
CHCla
CHCla
CHCl3
CHCl3
3.
TABLE 148,-Optical rotation and melting point of certain sugars and sugar derivatives—Continued
H OH H
d-GLUCOSE CH3OH−C——C—C——C—CHO
H
OH OH H OH
*- Molecu- tº * Q, YY -
Substance º Formula r lar * g [o]% [M] º Solvent
weight
oC g/100 ml
1-Nitro-2,3,4,6-tetraacetyl- 6 - d - | [66, 67 || C14H10O11N 377. 30. 96 — 8.4 –3, 170 1. CC14
glucose.
Pentapropionyl-d-glucose- - - - - - - [93] C2H32O11 460. 47 Oil -i-61.1 (16°) |_ _ _ _ _ _ _ _ _ 1 CHCla
Pentabutyryl-d-glucose-- - - - - - - - [93] C28H42O11 530. 60 9|| ##! (16°) |_ _ _ _ _ _ 750 6 §§
* 5 +29. +40, 750 2 ls
Pentapalmityl-o-d-glucose- - - - - - [93, 94 || Cs5H162011 1, 372. 17 65–67 | +34.3 (16°) +47, 070 4 CHCls
Pentapalmityl-3-d-glucose- - - - - - [94] Cs5H162O11 1, 372. 17| 72 +4.6 +6, 310 {3 CHCI's
Pentastearyl-o-d-glucose--- - - - - - [93] Co6H1s2O11 1, 512. 43| 70–71 | H-34.2 (16°) +51, 730 6 CHCla
Pentastearyl-8-d-glucose--- - - - - - [93, 94 || Co6H182011 1, 512. 43 78 + 14.1 +21, 330 9 CHCl3
Methyl ox-d-glucopyranoside----- [68, º C; H 14O6 194. I 8| 166 + 158.9 +30, 860 |0 H2O
70, 71]
Methyl 3-d-glucopyranoside----- [59, % C;H1406 194. 18, 105 — 34.2 –6, 640 |0 H2O
71, 72]
Methyl tetraacetyl-o-d-glucopy- º 55, C15H22O10 362. 33| 101–102 + 130.5 +47, 280 4 CHCls
ranoside. 59
Methyl tetraacetyl-3-d-glucopy- | [47, 59]| C15H22O10 362. 33 105 — 18.2 –6, 590 4 CHCI's
ranoside.
Methyl tetramethyl-o'-d-gluco- } * * -- + 153.9 |_ _ _ _ _ _ _ _ _ | 2 EtOH
pyranoside. [32] Culisz Og 250. 29 Sirup + 147.4 |_ _ _ _ _ _ _ _ _ |0 H2O
Methyl tetramethyl-3-d-gluco- [75, 76, C11 H22O6 250. 29 40–4] — 17.3 –4, 340 4 H2O
pyranoside. 77] 9.6 4, 630 5 H2O
Methyl 2,3,4-trimethyl - 3 - d - –––. M. < { 19.6 — 4, 2
glucopyranoside. º: º C10H2006 236. 26 93–94 |{_36; #. § 5 §h
Methyl 2,3,6-trimethyl - 3 - d - 21, 78, } --- {-3}. — a , 5 .1.1.2
glucopyranoside. 9] C10H2006 236. 26 59–60 || 1:... – 11, 220 5 CHCl,
:
Methyl 2,4,6-trimethyl - 3 - d - — 25.1 —5, 930 5 H2O
Mºś. hyl d [30, 78]| C10H2006 236. 26|| 70–71 {}} –6, % 5 §h
ethyl 3,4,6-trimethyl- 6 - d - — 7.3 — 1, 720 5 2
glucopyranoside. [31, 78]| C10H2006 236. 26 52-53 |{_i; 2 –3, 590 5 CHCl3
Methyl 2,3-dimethyl-o-d-gluco- [16] C9H18O, 222, 24 80–82 | + 142.6 +31, 690 5 2O
pyranoside.
Methyl 2,3-dimethyl-3-d-gluco- [78] C9H18O6 222. 24| 62–64 — 36.6 –8, 130 5 H2O
pyranoside.
Methyl d 2-methyl-3-d-glucopy- | [78] C3H16O6 208. 21| 97–98 || — 37.5 –7, 810 5 H2O
T8, DOS1C162.
Methyl d 6-methyl-3-d-glucopy- | [80] Cs H16O6 208. 21 133–135 – 27.0 (23°) –5, 620 5 H2O
T8, Il OSI C16.
Methyl ox-d-glucofuranoside- - - - - [81] C7H1406 194, 18 62–63 | + 118 +22, 910 5 H2O
Methyl 5, 6-o-d-glucofuranoside | [81] C3H12O7 220. 18 130 + 130 (23°) ––28, 620 1 MeOH
monocarbonate.
Methyl 5,6-8-d-glucofuranoside [82] C5H12O7 220. 18 143–145 – 66|o]; |_ _ _ _ _ _ _ _ _ 1 H2O
Mººn l-o'-d-gl + 102(18°) +25, 530 2 CHCI
ethyl tetramethyl-o-d-gluco- * O - y 3
furanoside. [81] | C11H22O6 250, 29| 11 + 107(18°) +26, 780 1 | H2O
Ethyl ox-d-glucofuranoside------- [82] C&H16O; 208. 21| 82–83 | +98(23°) +20, 400 2 H2O
Ethyl 3-d-glucofuranoside------- [81, 82]| C8H16O6 208. 21| 59–60 | –86(26°) – 17, 910 I H2O
Ethyl 5,6-o-d-glucofuranoside [81) C9H1407 234. 20 138–140 + 117 (17°) +27, 400 1 EtOH
monocarbonate.
Ethyl 5,6-8-d-glucofuranoside [82] C9H1407 234. 20, 164–165 – 50.6 [o]}; - - - - - - - - - 1 H2O
monocarbonate.
1,2-Monoacetone-d-glucose_-_ _ _ _ [83, 84 || Coh 16O6 220. 22| 161 — 11.8 – 2, 600 8 H2O
1,2-5,6-Diacetone-d-glucose- - - - - ſº 84, C15H26O6 260. 28, 110–11 || — 18.5 — 4, 820 5 H2O
5
d-Gluconic acid---------------- [86, 87]| C6H12O7 196. 16| 120–131 – 6.9 — 1, 350 5 | H2O
d-Gluconic Y-lactone- - - - - - - - - - - [87, 88]| C6H10O8 178. 14|| 133–135| + 68.0 + 12, 110 5 | H2O
d-Gluconic 6-lactone- - - - - - - - - - - [87, * C6H10O6 178. 14|| 150–152 + 66.2 + 11, 790 5 H2O
90
d-Gluconic amide--- - - - - - - - - - - - [91] C6H13O8.N 195. 17| 144 –– 31.2 + 6, 090 5 H2O
d-Gluconic phenylhydrazide-----| [86, 89]| C12H13O8 N2 286. 28, 200 + 12 + 3, 440 2 H2O
d-Glucal---------------------- [92] C6H10O4 146. 14| 60 — 7.2 — 1, 050 10 H2O
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
§
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;
Q
TABLE 1.48.-Optical rotation and melting point of certain sugars and sugar derivatives–Continued
4-GLUCOSIDO-MANNOSE (4-(6-d-glucopyranosido)-d-mannose)
Molec-
Refer- Melting on 1 y
& ſ. ‘mul l we 20 M
Substance €In CeS Formula wºit point |o]}} [M]
oC
4-Glucosido-o-mannose.H2O -- - - - - - - - - - - - - -] [2,3] C19H24O12 360. 31|| 137 + 14.7— + 5.9 + 5, 300
4-Glucosido-3-mannose - - - - - - - - - - - - - - - - - - - - | 1 C12H22O11 342. 30 203–205 – 6.5— + 6.5 –2, 200
Hexaacetyl-4-glucosido-mannose-- - - - - - - - - - - [1] C24 H34O17 594. 52 171 | +21.7 + 11, 900
Heptaacetyl-4-glucosido-mannose.-- - - - - - - - - - [1] C26H36O1s 636. 55 110 + 11.7 + 7, 450
Octaacetyl-4-glucosido-o-mannose - - - - - - - - - --- - [4] CºsłłąsC16 678, 59| 202–203 + 36.2 + 24, 600
Octaacetyl-4-glucosido-8-mannose----- - - - - - - || || 1 | C28H38019 678, 59 165 — 13.0 –8, 820
1-Fluoro-heptaacetyl-4-glucosido-o-mannose. [4] C26H35017 F 638. 54 155–156 -– 13.6 + 8, 680
1-Chloro-heptaacetyl-4-glucosido-oº-mannose-] [4] C26H35017Cl 655, 00, 172 + 51.2 + 33, 500
1-Bromo-heptaacetyl-4-glucosido-o-mannose. [4] X26H35017 Br 699. 46 168–169 +77.9 --54, 500
1-Iodo-heptaacetyl-4-glucosido-o-mannose - - -] [4] '96 H35017 I 746, 46. 140 + 111.5 +83, 230
Methyl 4-glucosido-o-mannopyranoside-----. | 5 | * 13 II 24V11 356, 32 227–228 + 46 (17°) + 16, 400
(Methyl 4-glucosido-3-mannopyrano- [1] 28H300.23 730. 66 229 — 48.5 2 – 17, 700
side)2.H2O.
Methyl heptaacetyl-4-glucosido-o-mannopy- | [ 1, 5] C27H35013 650. 58, 185 + 29.3 + 19, 100
ranoside.
Methyl heptaacetyl-4-glucosido-3-mannopy- [1] C27H3SOIs 650. 58, 178 – 23.2 – 15, 100
ranoside. |
1,2-[ Hexaacetyl-4-glucosido-man nose | | [1] C27H5O1s 650. 58 — 13.2 –8, 590
methyl orthoacetate.
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
2 Rotation calculated for one equivalent of the glycoside.
[1] H. S. Isbell, BS J. Research 7, 1115 (1931) RP392.
É #: Bergmann and H. Schotte, Ber. deut. chem. Ges. 54, 1570 (1921).
3] H.
S. Isbell, BS J. Research 5, 1179 (1930) RP253.
§ D. H. Brauns, J. Am. Chem. Soc. 48, 2776 (1926).
REFERENCES
165–167
5] W. N. Haworth, E. L. Hirst, H. R. L. Streight, H. A. Thomas, and J. T. Webb, J. Chem. Soc. 1930, 2636.
Concen-
tration
Solvent
g/100 ml
5
H2O
H2O
CHCla
CHCl3
CHCl3
CHCl3
CHCla
CHCl3
CHCl3
CHCl,
#6
CHC13
CHCla
CHCl3
3
----------
---
§
H OH. H. H H
d-or-GULOHEPTOSE * : CH3OH C C C—C—C—CHO
OH. H. OH OH OH
Molec- || Melt-
Substance . Formula ular ing [a]?' [M] º. Solvent
S weight | point
oC g/100 ml
o-d-o-Guloheptose- - - - - - - - - - - - - - - - - - - - - - - [1, 2] | CºPITAO: 210. 18 127 — 45.7— — 16.9 –9, 610 4| H2O
d-o-Guloheptonic acid-------------------- [ 1] C7H1408 226. 18, 128 — 12.6 –2, 850 4 H2O
d-or-Guloheptonic Y-lactone - - - - - - - - - - - - - - - [1] C7H12O7 208. 17| 1.45 +25.5 +5, 310 4| H2O
d-o-Guloheptonic phenylhydrazide - - - - - - - - - [ 1] C15H26O7.Ng 316. 31|| 156 +29.3 +9, 270 2 H2O
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses. * Isbell's nomenclature.
REFERENCES
ſ: H. S. Isbell, J. Research NBS 19, 639 (1937) RP1052.
2] H. S. Isbell, J. Research NBS 20, 97 (1938) RP1069.
H OH. H. H OH
d-6-GULOHEPTOSE * : CH3OH C C C C C CHO
OH. H. OH OH. H.
Molec- || Melt-
Substance lº Formula ular ing [o]}} 1 [M] º Solvent
$ weight | point
oC g/100 ml
o-d-8-Guloheptose- - - - - - - - - - - - - - - - - - - - - - - [1, 2] C; H 1407 210. 18 185–187] — 120.5— — 65.1 | – 25, 330 4 2O
d-6-Guloheptonic acid-- - - - - - - - - - - - - - - - - - - [3] CºH140s 226. 18, 135 —H 12.8 +2, 900 4| H2O
d-6-Guloheptonic phenylhydrazide- - - - - - - - - [1] C15H26O7.Ng 316. 31|| 191—192 — 15.4 –4, 870 8 H2O
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses. 2 Isbell’s nomenclature.
REFERENCES
§ F. B. LaForge, J. Biol. Chem. 41, 251 (1920).
2] H. S. Isbell, J. Research NBS 18, 505 (1937) RP990,
[3] H. S. Isbell, J. Research NBS 19, 639 (1937) RP1052,
3.
TABLE 148.—Optical rotation and melting point of certain sugars and sugar derivatives—Continued
H OH H H
d–GULOSE CH3OH C C C C—CHO
OH H OH OH
Molec- ë *
Substance . Formula ular * g [o]?' [M] º . Solvent
weight
oC g|100 ml
o:-d-Gulose. CaCl2.H2O * - - - - - - --> - ~ *-* = - m- [ 1, 2] C6H1407CaCl2 309. 17 205 +37.1– — 10 + 1 1, 470 7 H2O
(d-Gulose).3.CaCl2.H2O * * = ~ *- * * * *-* - * = - - [ 1 ] C12H26O15CaCl2 489. 32|_ _ _ _ _ _ _ _ + 29.4–2 – 16.5 |_ _ _ _ _ _ _ _ _ 4 H2O
d-Gulose phenylhydrazone. - - - - - - - - - [3] 12H18O3N2 270. 28 143 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
d-Gulose phenylosazone. ___ _ _ _ _ _ _ _ _ _ [4] C18H22O4N4 358. 39| 160 O— -- 16 (17°) 0 1 Pºt
3}t;O.
Pentaacetyl-d-gulose * * *-* - -- *- - - - - - * * * * [5] C18H22O11 390. 34 113 + 86.2 +33, 650 4 CHCl2
Methyl ox-d-gulopyranoside. H3O----- [6] 7 LL 16V7 212. 20 77 + 109.4 +23, 210 2| H2O
Methyl monoacetone-o-d-guloside----| [7] 10H18O3 234. 25 132–133 + 88.5 +20, 730 3| CHC13
Methyl 3-d-gulopyranoside---------- [6] C; H 1406 194. 18, 176 — 83.3 — 16, 180 3| H2O
Mºl tetraacetyl-o-d-gulopyrano- | [6] C15H22O10 362. 33| 98 ––97.3 +35, 250 3| CHCl3
S1C16.
Methyl tetraacetyl-3-d-gulopyrano- | [6] C15H22O10 362. 33| 67 — 32.1 — 11, 630 3| CH Cla
side.
d-Gulonic Y-lactone- - - - - - - - - - - - - - - - [8, 9] C6H10O6 178. 14, 182—185| – 57.1 — 10, 170 4| H2O
d-Gulonic amide--- - - - - - - - - - - - - - - - - [10, 11 || C6H13O8.N. 195. 17. 122–123| -- 16.1— + 13.9 +3, 140 6| H2O
! These values are read at 20° C except where the temperature is specified otherwise in parentheses.
REFERENCES
[1] H. S. Isbell and W. W. Pigman, J. Research NBS 18, 141 (1937) RP969.
|2| H. S. Isbell, BS_J. Research 5, 741 (1930) RP226.
É E. Fischer and R. Stahel, Ber. deut. chem. Ges. 24, 528 (1891).
: P. A. Levene, J. Biol. Chem. 59, 465 (1924).
[5] H. S. Isbell, heretofore unpublished measurement.
[6] H. S. Isbell, BS J. Research 8, 1 (1932) RP396.
[7] J. W. Oldham and G. J. Robertson, J. Chem. Soc. 1935, 685.
[8] J. U. W. Nef, Liebigs Ann. Chem. 403, 269 (1914).
[9] E. Fischer and R. Stahel, Ber. deut. chem. Ges. 24, 528 (1891).
[10] R. Weerman, Rec, trav, chim. 37, 16 (1917).
[11] C. S. Hudson and S. Komatsu, J. Am. Chem. Soc. 41, 1141 (1919).
§
OH OH
d-IDOSE CH2OH C C C C CHO
OH H OH. H.
Molec- e
Substance . Formula wººi * [o]}} [M] º: Solvent
eight
oC g/100 ml
d-Idonic phenylhydrazide--- - - - - - - - - - - - - - - - - - [1] C12H18O8N2 286. 28, 100–110| — 12.4 –3, 550 2 H2O
d-Idonic acid brucine salt---- - - - - - - - - - - - - - - - - [1, 2, 4 || C20H8801, N2 590. 61 188 — 25.8 — 15, 200 2 H2O
Cadmium d—idonate. Cabrz.H2O sº sº, ms. - sº me - - - - - - - - - [3] C12H24O15CdoBr2 792. 97 205 —3.2 –2, 540 10 H2O
Dibenzal-d-idonic acid----- - - - - - - - - - - - - - - - - - [2, 5] 20.1120V7 372. 36|| 227 — 57.8 –21, 500|- - - - - - - -
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
: J. U. W. Nef, Liebigs Ann. Chem. 403, 267 (1914).
2] F. Micheel and K. Kraft, Z. physiol. chem. 222, 235 (1933).
*
F (
E. Fischer and I. W. Fay, Ber. deut. chem. Ges. 28, 1975 (1895).
P. A. Levene and G. M. Meyer, J. Biol. chem. 26, 355 (1916).
W. A. van Ekenstein and C. A. Lobry de Bruyn, Rec. trav. chim. 18, 305 (1899).
REFERENCES
;
TABLE 148.-Optical rotation and melting point of certain sugars and sugar derivatives—Continued
LACTOSE (4-(6-d-galactopyranosido)-d-glucose)
Molec- e 4
Substance ºº Formula ular * [o]}' [M] º Solvent
weight
oC. g/100 ml
o-Lactose.H2O * *-** * *- :- - - --~ * * * * * * * * *-* - nº º º- - - [ 1, 2, C12H24O16 360. 31, 202 + 85.0— + 52.6 +30, 630 H2O.
3, 4
8–I actose [1, 4] C12H22O11 342. 30 252 + 34.9—, + 55. 4 –– 11, 950 4 H2O.
48 CUOS6––––––– - - - - - - - - - - - - - - - - - - - - [ 5, 6] C25H84010 N2 . 522. 54 {#. – 25.7 – 13, 400 1 || MeOH
Lactose benzylphenylhydrazone - - - - - - - 156–170 — 35.4 – 18, 500 3 Pyridine.
Lactose phenylosazone- - - - - - - - - - - - - - -] [7, 81 | C24H32O)NA 520. 53 210–212 — 25.4— —7.9% — 13, 200 1 MeOH
Lactose phenylosazone anhydride--- - - - [7, 8, 9]| C24H800s N4 502. 51] 231–232 – 147 –73, 900 (). 2 MeOH
Heptaacetyl-3-lactose - - - - - - - - - - - - - - - - [10] C26H36O18 636. 55 83 — 0.3(?) — 190 - - - - - - - - CHCla
Octaacetyl-o'-lactose - - - - - - - - - - - - - - - - - [11] C28H38O16 678, 59 152 + 53.6 + 36, 400 10 CHCl3
Octaacetyl-3-lactose---- - - - - - - - - - - - - - - [11, |2 28H38O16 678. 59 90 — 4.7 — 3, 200 10 CHCla
13
1-Chloro-heptaacetyl-o'-lactose----- - - - - [14, 15, C26H35017Cl 655. 00. 120–121| + 83.9 (22°) + 55,000 1. CHCl3
16, 17] -
1-Bromo-heptaacetyl-o'-lactose - - - - - - - - [16, 18, C26H35017 Br 699. 46|| 145 d. + 108.7 (23°) +76, 030 1 CHCla
19]
1-Iodo-heptaacetyl-o'-lactose - - - - - - - - - - [16] C26H3501, I 746. 46. 145 d. + 136.9 (23°) |+ 102, 200 1 CHCla
Methyl 3-lactoside --- - - - - - - - - - - - - - - - - [20] C18H24O11 356. 32 170–171 – - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Methyl heptaacetyl-3-lactoside - - - - - - - - [19] C27H38O1s 650. 58 76–77 | – 5.9(19°) —3, 800 7 CHC13
Methyl heptamethyl-6-lactoside - - - - - - - [21] 2011 38 V11 454. 51 77–82 + 5.2 +2, 400 1 H2O
Lactobionic 6-lactone----- - - - - - - - - - - - - [22] C12H2001, 340. 28, 195–1961 + 54—) + 22.3 + 18, 380 5 H2O
Calcium lactobionate-CabrzóH2O__ _ _ _ _ [23] C24H54O30Ca2Brz | 1062. 67|- - - - - - - - –– 18.7 + 19, 900 7 H2O
Lactal------------------------------ [24, 25, 12 L L 20\J.9 308. 28, 191–192 +27.5 (23°) + 8, 480 2 H2O
26]
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
2 After 9 hours.
§
|REFERENCES
H. S. Isbell and W. W. Pigman, J. Research N BS 18, 141 (1937) RP969.
H. Trey, Z. physik. Chem. 46, 620 (1903).
C. S., Hudson, Z. physik. Chem. 44, 417 (1903); J. Am. Chem. Soc. 32, 889 (1910).
. Gillis, Rec. trav. chim. 39, 88, 677 (1920).
J
} W. A. van Ekenstein and C. A. Lobry de Bruyn, Rec. trav. chim. 15, 226 (1896).
Hofmann, Liebigs Ann. Chem. 366,304 (1909).
Fischer, Ber. deut. chem. Ges. 41, 76 (1908); 20, 828 (1887).
Votoček and F. Valentine, Coll. trav. chim. Czech. 3, 432 (1931).
F. Percival and E. G. Percival, J. Chem. Soc. 1937, 1320.
S. Hudson and R. Sayre, J. Am. Chem. Soc. 38, 1867 (1916).
S. Hudson and J. M. Johnson, J. Am. Chem. Soc. 37, 1270 (1915).
Herzfeld, Ber. deut. chem. Ges. 13, 265 (1880).
. Schmoeger, Ber. deut. chem. Ges. 25, 1452 (1892).
Bodart, Monatsh. 23, 5 (1902).
Fischer and E. F. Armstrong, Ber. deut. chem. Ges. 35,833 (1902).
S. Hudson and A. Kunz, J. Am. Chem. Soc. 47, 2052 (1925).
PacSu, Ber. deut. chem. Ges. 61, 1508 (1928). .
Fischer and H. Fischer, Ber. deut. chem. Ges. 43, 2521 (1910).
Ditmar, Monatsh. 23, 865 (1902).
Ditmar, Ber. deut. chem. Ges. 35, 1951 (1902).
. N. Haworth and G. C. Leitch, J. Chem. Soc. 113, 188 (1918).
S. Isbell, BS J. Research 11, 713 (1933) RP618.
S. Isbell, J. Research NBS 17, 331 (1936) RP914.
Fischer and G. O. Curme, Jr., Ber. deut. chem. Ges. 47, 2049 (1914).
. Bergmann, Liebigs Ann. Chem. 434, 79 (1923).
. N. Haworth, E. L. Hirst, M. M. T. Plant, and R. J. W. Reynolds, J. Chem. Soc. 1930, 2644.
3.
TABLE 148.-Optical rotation and melting point of certain sugars and sugar derivatives—Continued
H OH OH
d-lyxoseſ CH.OH–C–C–C–CHO
OH. H. H
* Molec- s
Substance º: Formula wº * [a]%" [M] º Solvent
eight
oC g|100 ml
o-d-Lyxose-------------------------- [1, 2, 3, C5H10O3 150. 13 106–107| + 5.6— — 13.8 + 840 4| H2O
4]
8-d-Lyxose-------------------------- [1, 3] C5H10Os 150. 13 117–118 – 72.6— – 13.8 ||—10, 900 4| H2O
d–Lyxose p-bromphenylhydrazone - - - - - [2, 5] C11H15O4N2Br 319. 16, 156–157| -- 34.5— -- 10.0 |-|- 11, 000 1| Pyridine.
2,3,4-Trimethyl-a-d-lyxose- - - - - - - - - - - - [6] C5H16O5 192. 21 || 79 – 11.9— —21.8% –2, 300 2 H2O
Tetraacetyl-o'-d-lyxose----- - - - - - - - - - - - [7] C18H18Og 318, 28 93–94 | +25 (25°) +8, 000|_ _ _ _ _ _ _ _ CHCla
1,2-[3,4-Diacetyl-d-lyxose ] methyl or- | [7] C19H18O3 290. 27 90 – 103.5 (22°) |–30, 040 4| CHCla
thoacetate.
Methyl ox-d-lyxopyranoside------------ [8, 9] C6H12O5 164. 16. 108–109 -- 59.4 +9, 750 5| H2O
Methyl 3-d-lyxopyranoside------- - - - - - [10] C6H12O5 164. 16| 118 — 128.1 –21, 030 2 H2O
Methyl triacetyl-o-d-lyxopyranoside - - - | [7, 11 | | C12H18Og 290. 27| 96 +30.1 +8, 740 1 CHCl3
Methyl triacetyl-3-d-lyxopyranoside----| [10] C19H18Os 290. 27| 88–89 || – 109.5 –31, 780 4| CHCl3
Monoacetone-d-lyxose-- - - - - - - - - - - - - - - [5] 8.L.I. 14 V5 190. 19 79–80 | ––26.0 (25°) +4, 940|_ _ _ _ _ _ _ _ Acetone.
d–Lyxonic acid---------------------- [4, 12] 511 10\_J6 166. 13|_ _ _ _ _ _ _ _ + 6.6-> -- 52.7% + 1, 100 2| 0.1 N H Cl
d–Lyxonic lactone-------------------- [4, 13, C5H8O; 148. 11| 113–114| + 81.5 + 12,070 4| H2O
14]
d–Lyxonic phenylhydrazide 4 - - - - - - - - - - [4, 13, ] C11H15O5N2 256. 26, 164 — 13.7 –3, 510 4| H2O
14, 15
| These values are read at 20° C except where the temperature is specified otherwise in parentleses.
2 At 1.5 and 28 minutes.
3 Af 11 minutes and 66 days.
4 Crystallizes as dihydrate, mp 142°C,
E
H.
F.
] K
| J.
J.
E.
G.
REFERENCES
| H. S. Isbell and W. W. Pigman, J. Research NBS 18, 141 (1937) RP969.
R. Weerman, Rec. trav. chim. 37, 31 (1918).
| W. N. Haworth and E. L. Hirst, J. Chem. Soc. 1928, 1221.
| E. Fischer and O. Bromberg, Ber. deut. chem. Ges. 29, 581 (1896).
P. A. Levene and R. Tipson, J. Biol. Chem. 115, 731 (1936).
] E. L. Hirst and J. A. B. Smith, J. Chem. Soc. 1928, 3147.
| P. A. Levene and M. L. Wolfrom, J. Biol. Chem. 78, 525 (1928); 79, 471 (1928).
W. A. van Ekenstein and J. J. Blanksma, Z. Ver. deut. Zucker-Ind. 58, 114 (1908}
j F. P. Phelps and C. S. Hudson, J. Am. Chem. Soc. 48, 503 (1926).
S. Isbell and H. L. Frush, J. Research NBS 24, 125 (1940) RP1274.
P. Phelps and C. S. Hudson, J. Am. Chem. Soc. 50, 2049 (1928).
. Rehorst, Liebigs Ann. Chem. 503, 158 (1933).
U. W. Nef, Liebigs Ann. Chem. 403, 248 (1913).
U. W. Nef, O. F. Hedenburg, and J. W. E. Glattfeld, J. Am. Chem. Soc. 39, 1651 (1917).
Fischer and O. Bromberg, Ber. deut. chem. Ges. 29, 2068 (1896).
Bertrand, Bull. Soc. chim. [3] 15, 592 (1896).
º
MALTOSE (4-(o-d-glucopyranosido)-d-glucose)
Refer- Melting 1 ."
Substance Formula ular - 20 [M]
€In CeS weight point [o]%
3-Maltose.H2O - - - - - - - - - - - - - - - - - - - - - [1,2] C12H24O12 360. 31|| 102–103 + 111.7— -- 130.4 || --40, 250
Maltose 3-naphthylhydrazone-- - - - - - - [3] C23H30010 N2 482. 48, 176 + 10.6 + 5, 110
Maltose phenylosazone-- - - - - - - - - - - - - [4, 5] C24H82O3 N4 520. 53| 206 + 82.6 +43,000
Heptaacetyl-3-maltose - - - - - - - - - - - - - - 6, 7, 8 || C26H36O18 636. 55, 181 + 67.8— + 110 +43, 100
Octaacetyl-o-maltose - *-* - - - - - - - - - - - - - - ſ 9, 11] C28H38O16 678. 59 125 + 122.8 –H 83, 330
Octaacetyl-3-maltose--- - - - - - - - - - - - - - 10, 11 || C28H35016 678. 59 159–160 —- 62.6 +42, 500
1-Fluoro-heptaacetyl-o-maltose--- - - - - [12] C26H35017F 638. 54|| 174–175 –– 111.1 +70, 940
1-Chloro-heptaacetyl-o-maltose_-_ _ _ _ _| [12, 13, C26H35017Cl 655. 00. 125 + 159.5 + 104, 500
14]
1-Bromo-heptaacetyl-o-maltose_-_ _ _ _ _ [12] C26H35017 Br 699. 46 112–113 - 180.1 + 126,000
1-Nitro-heptaacetyl-o-maltose - - - - - - - - [15] 26.Ll 35V 19 665. 55 93–95 –– 149.3 (19°) +99, 370
1,2-[Hexaacetylmaltose] Orthoacetyl | [16, 17]| C26H35017Cl 655. 00. 112–114 –- 67.5 +44, 200
chloride.
Methyl 3-maltoside *- - - - - - - - - - - - - - - - [15, § C18H24O11 356, 32 155 ––83.9 +29, 900
19, 20
Methyl heptaacetyl-3-maltoside_ _ _ _ _ _ [7, 15, C27H36O18 650. 58 128–129 -- 53.5 +34,800
18]
1,2-[Hexaacetylmaltose) methyl ortho- [17] C27H3301s 650. 58 163–164| + 101.6 [o]57s |_ _ _ _ _ _ _ _ _
Concen-
tration
g/100 ml
4
1.
.
Solvent
H2O
MeOH
Pyridine +
EtOH
CHCls
CHCla
CHCls
CHCla
CHC13
CHCl3
CHC13
CHCl3
H2O
CHCls
C2H2Cl,
Molec-
acetate.
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
2 IDried over P2O5.
Compound crystallizes as monohydrate, m.p. 110°C.
3.
#
20]
REFERENCES
H. S. Isbell and W. W. Pigman, J. Research NBS 18, 141 (1937) RP969.
J. Gillis, Chem. Abst. 25, 1805 (1931). e
W. Van Ekenstein and C. Lobry de Bruyn, Rec, trav; chim, 15, 225 (1896).
E. Fischer, Ber. deut. chem. Ges. 17, 583 (1894); 20, 831 (1897).
| C. Neuberg, Ber. deut. chem. Ges. 32, 3386 (1899); P. Brigl and P. Mistele, Z. physiol, chem. 126, 128 (1923).
E. Fischer and H. Fischer, Ber. deut. Chem. Ges. 43, 2521 (1910).
C. S. Hudson and R. Sayre, J. Am. Chem. Soc. 38, 1867 (1916).
P. Karrer and C. Naegeli, Helv. Chim. Acta 4, 169 (1921).
A. Herzfeld, Ber. deut. chem. Ges. 13, 267 (1880); LiebigS Ann. Chem. 220, 215 (1883).
| A. R. Ling and J. L. Baker, J. Chem. Soc. 67,212 (1895); Ber. deut. chem. Ges. 28, 1019 (1895).
S. Hudson and J. M. Johnson, J. Am. Chem. Soc. 37, 1276 (1915).
H. Brauns, J. Am. Chem. Soc. 51, 1820 (1929).
C.
| D.
#. Foerg, Monatsh 23, 45 (1902).
Schliephacke, Liebigs Ann. Chem. 377, 184 (1910).
W. Koenigs and E. Knorr, Ber. deut. chem. Ges. 34, 4343 (1901).
K. Freudenberg and O. Ivers, Ber. deut. chem. Ges. 55,929 (1922).
] K. Freudenberg, H. von Hochstetter, and H. Engels, Ber. deut. chem. Ges. 58, 666 (1925).
E. Fischer and E. F. Armstrong, Ber. deut. chem. Ges. 34, 2885 (1901); 35, 840 (1902).
B. Helferich and J. Becker, Liebigs Ann. Chem. 440, 1 (1924)
J. C. Irvine and I. M. A. Black, J. Chem. Soc. 1926, 862.
i.
TABLE 148.-Optical rotation and melting point of certain sugars and sugar derivatives—Continued
H H OH OH H
d-o-MANNO HEPTOSE CH2OH C C C C C CHO
OH OH H H OH
Molec- e
Refer- - Melting 20 1 Cor.cen-
Substance €In CéS Formula wº t| point [o]}} [M] tº Solvent
oC g/100 ml
o-d-o-Mannoheptose.H2O-- - - - - - - - - - - - - - [1, 2] | CFBItg|Os 228, 20. 107 + 120.0— -|-64.7 |-|-27, 380 4| H2O
8-d-o-Mannoheptose.H2O -- - - - - - - - - - - - - - [1] C;H16Os 228. 20 104 +42.3— + 64.5 +9, 650 4| H2O
d-o-Mannoheptose phenylhydrazone.------ [2] C18H26O6N2 300, 31|| 197–200|_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
d-Mannoheptose phenylosazone- - - - - - - - - - [2] C19H24O5N4 388. 42| 200 +27.2 + 10, 570 1| Acetic acid
Hexaacetyl-o'-d-o-mannoheptose- - - - - - - - - 3. 19-il 26V13 462. 40, 75–76 | + 120.8 +55, 860 1 CHCl3
Hexaacetyl-3-d-o-mannoheptose------- - - - 3. 1911 26V13 462. 40|| 107 —H 34.1 + 15, 770 1 CHCla
2,3,4,5,6,7-Hexaacetyl-d-o-mannoheptose - [3] 19H26O18 462. 40|| 146 –34 — 15, 700 1| CHCl,
Methyl d-o-mannoheptofuranoside------- [3] /8LL 16V7 224, 21 | 115 — 1 || –24, 900|_ _ _ _ _ _ _ _ H2O
Methyl pentaacetyl-d-o-mannoheptofur- [3] C15H26O12 434, 39| 76–77 | — 42.9 – 18, 630 - - - - - - - - CHCla
anoside
d-o-Manmoheptonic acid- - - - - - - - - - - - - - - - [2, 4 || || CFH140s 226, 18 175 (-) ---------------- H2O
d-o-Mannoheptonic Y-lactone------- - - - - - [2, 4} | CFLI190; 208. 17| 148–150 – 74.2 – 15, 450 10| H2O
d-o-Mannoheptonic amide - - - - - - - - - - - - - - [5 C; H15O1N 225, 20, 193–194| +28.0 +6, 310 1| H2O
d-o-Mannoheptonic phenylhydrazide- - - - - | 6, 7} | C18H2007 N2 316. 31|| 220–223 ––21 (80°) +6, 600 3| H2O
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
S. Hudson, J. Am. Chem. Soc. 39, 462 (1917).
7
|
. S. Isbell, J. Research NBS 18, 505 (1937) RP990; 20, 97 (1938) RP1069.
. Fischer and F. Passmore, Ber. deut. chem. Ges. 23, 2226 (1890).
. M. Montgomery and C. S. Hudson, J. Am. Chem. Soc. 56, 2463 (1934).
Fischer and J. Hirschberger, Ber. deut. Chem. Ges. 22, 365 (1889).
S. Hudson and K. P. Monroe, J. Am. Chem. Soc. 41, 1140 (1919).
. Fischer and F. Passmore, Ber. deut chem. Ges. 22, 2728 (1889).
REFERENCES
3.
H H OH OH OH
d-3-MANNoHEPTose CH3OH−C C C C C CHO
OH OH H H H
Molec- e
Substance . Formula ular ** [a]?' [M] º Solvent
weight
oC g|100 ml
o-d-8-Mannoheptose.H2O -- - - - - - - - - - - - - - - [1, 2] CFH16Og 228. 20 83 +45.7— + 14.5 |+ 10, 430 4| H2O
d-8-Mannoheptose p-bromophenylhydra- | [2] C18H16O6N2Br 379. 22, 191-193|- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
ZOIlê
d-8-Mannoheptonic acid-- - - - - - - - - - - - - - - - [ 1, 2] C; H1408 226. I9| 155 +4.0— — 25.0 —-900 4| H2O
d-8-Mannoheptonic Y-lactone_-_____ _ _ _ _ _ _ [1] CºEI12O7 208. 17| 130 — 35.7— — 27.9 –7, 430 4| H2O
d-8-Mannoheptonic phenylhydrazide- - - - - - [3] C15H26O7N2 316. 31|| 190 –25.8 (27°) –8, 160 4| H2O
! These values are read at 20° C except where the temperature is specified otherwise in parentheses.
REFERENCES
[1] H. S. Isbell, J. Research NBS 20, 97 (1938) RP1069.
É §. Ettel, Coll. Czech. Chem. Comm. 4, 504 (1932).
Peirce, J. Biol. Chem. 23, 327 (1915).
3.
TABLE 148.-Optical rotation and melting point of certain sugars and sugar derivatives—Continued
H H OH OH
d-MANNOSE CH3OH C C C C CHO
OH OH. H. H
Molec- g
Refer- { ſº fºr Melting 20 ! Concen- y
Substance €IlC6S Formula ular point [o]}} [M] tration Solvent
weight
oC g/100 ml
o-d-Mannose--------------------- [1, 2] C6H12O6 180. 16. 133 +29.3— — — 14.2 + 5, 280 4| H2O.
8-d-Mannose--------------------- [1, 3] 6.Ll 12V6 180. 16| 132 — 17.0— — — 14.2 –3, 060 4| H2O.
d–Mannose. CaCl2.4H2O_ _ _ _ _ _ _ _ _ _ _ _ [1,4] C6H20010CaCl2 363. 22 101–102 – 31.3— -|-6.0 ° — 11, 370 9| H2O.
d–Mannose phenylhydrazone- - - - - - - [5, 6] C19H18O3N2 270. 28, 199—200 +26.3—5. H-33.84 + 7, 110|_ _ _ _ _ _ _ _ Pyridine
3,4-Dimethyl-d-mannose.H2O - - - - - - [7] C8H18O, 226. 23 107–109| ?— +3 -------- 2 H2O.
3,4,6-Trimethyl-o-d-mannose---- - - - [8] C9H18O3 222. 24| 101–102 + 21— +8.2 (22°) ––4, 700 1| H2O.
2,3,4-Trimethyl-d-mannose- - - - - - - - [7] Qll 18V6 222. 24| 102–103| ?— +7 |_ _ _ _ _ _ _ _ 5| H2O.
2,3,4,6–Tetramethyl-d-mannose----- [9] C10H2006 236. 26|| 50– 52 + 7.4— +2.4 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ H2O.
2,3,4,6-Tetraacetyl-d-mannose *__ ___ [10] C14H20O10 348. 30, 159–160 –24.2 (19°) –8, 430 1 CHCl3
2,3,4,6–Tetraacetyl-d-mannose 8- - - - - [11] 14 L120V V10 348. 30| 93 +26. 3 (27°) +9, 160 1| CHCl3
1,2,3,4,6-Pentaacetyl-o'-d-mannose--| [12] C18H22O11 390, 34| 64 + 55.0 +21, 470 4| CHCl3
1,2,3,4,6-Pentaacetyl-3-d-mannose--| [13, 16]| C18H22O11 390. 34|| 117–118) — 25.2 –9, 840 3| CHCl3
1, 1’, 2,3,4,5,6-Heptaacetyl-d-man- | [14] 2011 28V 14 492. 43| 122 +0.4 +200|_ _ _ _ _ _ _ _ CHCl3
Il OSC.
1, 2-[3,4,6-triacetyl – d – mannose] | [15] C15H22O10 362. 33| 105 — 26.6 –9, 640 4| CHCl3
methyl orthoacetate.
1- Fluoro-2,3,4,6-tetraacetyl-o'-d- | [16] C14H10O3F 350. 29| 68–69 || +21.5 +7, 530 2| CHCl3
II].8,I) In OS6.
1- Chloro-2, 3,4,6-tetraacetyl-o'-d- | [16, 17]| C14H10O3Cl 366. 75|| 81 –H 89.9 +32, 970 2 CHCl2
IIla, Ill] OS62.
1-Bromo-2,3,4,6-tetraacetyl-o'-d- [10, 11, C14H10OgEr 411. 21 | 62 + 131.6 + 54, 120 2| CHCls
II].8, Ill.) OS6. 16]
1-Iodo-2,3,4,6-tetraacetyl-o'-d-man- | [16] C14H10O. I 458. 21 95 -- 190.5 +87, 290 2 CHCl3
In OSé.
Methyl ox-d-mannopyranoside - - - - - - [3, 18, 19 || C. HiſOc 194, 18, 193–194 || -- 79.2 + 15, 380 1| HoO.
3.
Methyl 3-d-mannopyranoside iso- [20] C10H22O;
propyl alcoholate.
Methyl tetraacetyl-o'-d-mannopyr- [15] C15H22O10
anoside.
Methyl tetraacetyl-3-d-mannopyr- | [15] C15H22O10
anoside. -
Methyl tetramethyl-o-d-mannopyr- | [21, 22 || C11H22O6
anoside.
Methyl tetramethyl-3-d-mannopyl- | [8] Chih 22O6
anoside.
Methyl ox-d-mannofuranoside------- [23] C; H 14O6
Methyl tetraacetyl-a-d-mannofur- [24] C15H22O10
anoside.
Methyl tetramethyl-o-d-mannofur- [24] C11H22O6
anoside.
2,3-5,6-Diacetone-d-mannose------- [25, 26]| C15H26O6
d-Mannonic 6-lactone- - - - - - - - - - - - - [27, 28]| C6H10Og
d-Mannonic Y-lactone- - - - - - - - - - - - - [27, 28, C6H10O8
29]
d-Mannonic amide---------------- [30] C6H13O8 N
d-Mannonic phenylhydrazide------- [31] C19H18OcN2
250.
194.
362.
250.
260
173.
178.
195.
286.
. 23
. 33
. 33
. 29
29
18
33
29
28
14
14
17
28
74— 75 – 53. 3 — 13, 550 4 H2O.
65 +49.1 + 17, 790 4| CHC]3.
161 —50. 4 — 18, 260 1 CHC]3.
37–38 +42.9 + 10, 740 10| H2O.
37 —80 –20, 020 1| H2O.
118–119 + 113 +21, 940 1| H2O.
63 + 107 (19°) +38, 770 1| CHCl3.
24 --98.6 (19°) +24, 680 1| H2O.
122 + 11.9— -- 1.1 + (16°)| +3, 100 1| H2O.
158—160 + 114.8— +30.3 * |+20, 450 5| H2O.
151—152 + 51, 5 +9, 170 5| H2O.
173 — 17.3 –3, 380 1| H2O.
214–216 – 8.1 (80°) –2, 320|_ _ _ _ _ _ _ _ H2O
These values are read at 20° C except where the temperature is specified otherwise in parentheses.
3 The structures of these compounds are open to question. For this reason, they have not been classified as alpha and beta isomers.
REFERENCES
|16] D. H. Brauns, BS J. Research 7, 573 (1931) RP358.
1] H. S. Isbell and W. W. Pigman, J. Research N BS 18, 141 (1937) RP969.
] P. A. Levene, J. Biol. Chem. 57, 329 (1923); 59, 129 (1924).
* Complex mutarotation having maximum value.
* Complex mutarotation having minimum value.
5 Rotation after 2 minutes and 24 hours.
§ W. A. Van Ekenstein, Rec. trav. chim. 15, 221 (1896
[4] J. K. Dale, J. Am. Chem. Soc. 51, 2788 (1929).
5] C. Butler and L. Cretcher, J. Am. Chem. Soc. 53, 4358 (1931).
6
7
[8
2
} A. Hofmann, Liebigs Ann. Chem. 366, 277 (1909).
] W. N. Haworth, E. L. Hirst, and F. A. Isherwood, J. Chem. Soc. 1937, 784.
8] H. G. Bott, W. N. Haworth, and E. L. Hirst, J. Chem. Soc. 1930, 1395, 2653.
[9] W. L. Lewis and R. D. Greene, Science 64, 206 (1926).
[10] F. Micheel and H. Micheel, Ber, deut; chem. Ges. 63,386 (1930).
[11] P. A. Levene and R. S. Tipson, J. Biol. Chem. 90, 89 (1931).
[12] C. S. Hudson and J. K. Dale, J. Am. Chem. Soc. 37, 1280 (1915).
[13] E. Fischer and R. Oetker, Ber. deut. chem. Ges. 46, 4029 (1913).
[14] N. W. Pirie, Biochem. J. 30, 374 (1936).
[15] J. K. Dale, J. Am. Chem. Soc. 46, 1048 (1924); T. L. Harris, E. L. Hirst, and
C. E. Wood, J. Chem. Soc. 1932, 2108.
[17]
[18]
19
|
D. H. Brauns, J. Am. Chem. Soc. 44, 401 (1922).
E. Fischer and L. Beensch, Ber. deut. chem. Ges. 29, 2927 (1896).
H. Hérissey, Compt. rend. 173, 1406 (1921).
| H. S. Isbell and H. L. Frush, J. Research N BS 24, 125 (1940) RP1274.
!
. C. Irvine and A. Moodie, J. Chem. Soc. 87, 1462 (1905).
W. N. Haworth, J. Chem. Soc. 107, 8 (1915).
. N. Haworth and C. R. Porter, J. Chem. Soc. 1930, 649.
W. N. Haworth, E. L. Hirst, and J. I. Webb, J. Chem. Soc. 1930, 651.
C. Irvine and A. Skinner, J. Chem. Soc. 1926, 1089.
Freudenberg and R. M. Hixon, Ber. deut. chem. Ges. 56, 2119 (1923).
S. Isbell and H. L. Frush, BS J. Research 11, 649 (1933) RP613.
|U. W. Nef, Liebigs Ann. Chem. 403, 306 (1914).
. Fischer and J. Hirschberger, Ber. deut. chem, Ges. 22, 3218 (1889).
. S. Hudson and S. Komatsu, J. Am. Chem. Soc. 41, 1141 (1919).
. S. Hudson, J. Am. Chem. Soc. 39, 462 (1917).
W
e
-
º
-
3.
TABLE 148.—Optical rotation and melting point of certain sugars and sugar derivatives—Continued
MELEZITOSE (glucosido-sucrose)
Molec- gº
Refer- Melting 20 ! - Concen- y
Substance el) CeS Formula ular point [o]}} [M] tration Solvent
weight
oC g/100 ml
Melezitose.2H2O .* = <-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - [1, 2] C18H38018 540, 47| 153–154 --88.2 +47, 670 4 H2O
Hendekaacetylmelezitose - - - - - - - - - - - - - - - - - - - - - - - - [3, 4} C40H54O27 966, 84| 117 + 103.6 |-|- 100, 160 1 CHCla
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses. -
REFERENCES
[1] R. Kuhn and G. E. v. Grundherr, Ber. deut. chem. Ges. 59, 1655 (1926). [3] A. Alekhine, Ann. chim. phys. 18, 532 (1889). -
[2] E. O. v. Lippmann, Ber. deut. chem. Ges. 60, 161 (1927). [4] C. S. Hudson and S. F. Sherwood, J. Am. Chem. Soc. 40, 1456 (1918).
MELIBIOSE (6-(o-d-galactopyranosido)-d-glucose)
- Molec- * º
Substance . Formula ular * [a]?' [M] ‘. Solvent
weight
oC g/100 ml
8-Melibiose.2H2O__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ [1, 2] C12H26O13 378. 33 82— 85 + 111.7— + 129.5 | +42, 260 4| H2O
Melibiose phenylhydrazone- - - - - - - - - - - |[3] C15H23010 N2 432. 42. 145 |-----------------|---------|- - - - - - - -
Melibiose phenylosazone.-------------- [3, 5] C24 H32O3 N. 520. 53| 176–178 + 43.2 (21°) +22,490 9| Pyridine
Heptaacetyl-3-melibiose -- - - - - - - - - - - - - [4] C28H38O13 636. 55, 193 + º 125.82 +75, 700 6| CHC13
249
Octaacetyl-3-melibiose - - - - - - - - - - - - - - [3, 6, 7]| CºgPI38O10 678. 59, 177. 5 + 102.5 +69, 560|- - - - - - - - CHC],
1-Fluoro-heptaacetyl-o-melibiose - - - - - - [8] C26H35017F 638. 54 135 + 149.7 +95, 590 2| CHCla
1-Chloro-heptaacetyl-o-melibiose - - - - - - [8] C26H35017Cl 655. 00. 127 –– 192.5 - + 126,090 2 CHCla
1-Bromo-heptaacetyl-o-melibiose - - - - - - [8] C26H35017 Br 699. 46 116 – 209.9 –– 146, 820 2 CHCla
Methyl heptaacetyl-3-melibioside------ [4] C27H33Ois 650. 58. 158—160 —-92.7 (18°) +60, 310 4 CHCla
Methyl heptamethyl-3-melibioside- - - - - [9] C26H3sOil 454. 51 | 106–107| + 97.8 +44, 450 1| H2O
! These values are read at 20° C except where the temperature is specified otherwise in parentheses. * A ſter 10 minutes and 14 hours.
3.
} H. S. Isbell and W. W. Pigman, heretofore unpublished measurement.
2] A. Bau, Z. Ver. deut. Zucker-Ind. 54, 481 (1904); 49, 850 (1899).
} C. Scheibler and H. Mittelmeier, Ber. deut. chem. Ges. 23, 1438 (1890).
4] B. Helferich and S. R. Petersen, Ber. deut. chem. Ges. 68, 790 (1935).
3. B. Helferich and H. Rauch, Ber. deut. chem. Ges. 59, 2655 (1926).
6] C. S. Hudson and J. M. Johnson, J. Am. Chem. Soc. 37, 2752 (1915).
§ B. Helferich and H. Bredereck, Liebigs Ann. Chem. 465, 166 (1928).
[8] D. H. Brauns, J. Am. Chem. Soc. 51, 1820 (1929).
() W. Charlton, W. N. Haworth, and W. Hickinbottom, J. Chem. Soc. 1927, 1527.
NEOLACTOSE (4-(6-d-galactopyranosido)-d-altrose)
Molec- &
-re -*. Refer- * Melting 20 A Concen-
Substance €I) CGS Formula wº t| point [o]} [M] tration Solvent
oC g/100 ml
8-Neolactose------------------------------ [1, 2] C12H22O11 342. 30, 190 +33.8— +35.5 |-|-11, 570 8| H2O
g-Neolactose phenylosazone-- - - - - - - - - - - - - - - - [3] C24H32O, N, 520. 54, 195 |---------------|--------|--------
Heptaacetyl-o'-neolactose- - - - - - - - - - - - - - - - - - - [2] C28H38Ois 636. 55 85–95 + 23.3— +21.0 |-|- 14, 830 8| CHCl3
Heptaacetyl-3-neolactose- - - - - - - - - - - - - - - - - - - [2] 26.11.36V18 636. 55| 135–136|| + 10.0— +21.0 | +6, 370 4–8 CHCl3
Octaacetyl-o'-neolactose- - - - - - - - - - - - - - - - - - - - [3] C28H38O16 678. 59 178 + 53.4 (24°) ––36, 240 1 CHCl3
Octaacetyl-3-neolactose------- - - - - - - - - - - - - - - [3] C28H38O19 678, 59| 148 –7.1 (24°) — 4, 820 1 CHCl3
1-Chloro-heptaacetyl-o'-neolactose- - - - - - - - - - - [2, 3] C26H350,7Cl 655. 00. 182 + 71.2 +46, 640 1 CHCl,
REFERENCES
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
REFERENCES
| H. S. Isbell and W. W. Pigman, heretofore unpublished measurement.
2] N. K. Richtmyer and C. S. Hudson, J. Am. Chem. Soc. 57. 1716 (1935).
[3] A. Kunz and C. S. Hudson, J. Am. Chern. Soc. 48, 1978, 2435 (1926).
3.
TABLE 1.48.-Optical rotation and melting point of certain sugars and sugar derivatives—Continued
RAFFINOSE (d-galactosido-sucrose)
Molec- *
* Refer- Melting 20 ! / Concen- *
Substance €In CeS Formula wº t point [o] [M] tration Solvent
oC g/ (00 ml
Raffinose.5H2O * * *-* * * * * - * - *-* *-* * * *-* * * * * * -s ºm º ºs º-'º - º ºs º- amº - mº, [1, 2, 3] C15H12O2 594. 52 80 + 105.2 + 62, 540 4 H2O
Hendecaacetylraffinose------------------------- [4, 5} C40H54O9; 966, 84| 99-–10] +92.2 |-|-89, 140 8. EtOH
1These values are read at 20° C except where the temperature is specified otherwise in parentheses. -- - - - ----- -— — — . -- = — . .-----mº
REFERENCES
§ C. Scheibler, Ber. deut. chem. Ges. 19, 2868 (1886).
2] D. Loiseau, Compt. rend. 82, 1058 (1876).
3j H. Grossmann and F. L. Bloch, Z. Verein. deut. Zucker-Ind. 62, 70 (1912).
[4] C. Scheibler and H. Mittelmeier, Ber. deut. chem. Ges. 23, 1438 (1890).
[5] C. Tanret, Bul. Soc. chim. 13, 261 (1895).
OH OH. H. H
l-RHAMNOSE CH3 C C C C CHO
H H OH OH
Molec- gº
Refer- { ſº Yery" Melting 20 ! Concen- *
Substance €Il CeS Formula wºit point |o]}} [M] 1. Solvent
oC g/100 ml
o:-l-Rhamnose.H2O -- - - - - - - - - - - - - - - - - - - - [1, 2] C6H1406 182. 17| 93–94 | – 8.6— — — 8.2 – 1, 570 4| H2O
6-l-Rhamnose- - - - - - - - - - - - - - - - - - - - - - - - - [3, 4, 5] C6H12O5 164. 16 123–125 + 38.4— ––8. 9 ––6, 300|- - - - - - - - H2O
l-Rhamnose phenylhydrazone - - - - - - - - - - - [6, 7, 8] C19H13O4N2 254. 28. 158–159 -- 57.1%– +44.3 + 14, 520 - - - - - - - - H2O
l-Rhamnose phenylosazone_--_ _ _ _ _ _ _ _ _ _ _ | [9] C18H22O3N4 342. 39| 222 +94 +32, 200 2. Pyridine.
4-Methyl-3-l-rhamnose - - - - - - - - - - - - - - - - - [10, 11] C;H1405 178. 18, 122 + 12.9 (24°) ––2, 300 1| Mo OH
3.
3,4-Dimethyl-l-rhamnose----- - - - - - - - - - - -
5-Methyl-l-rhamnose--- - - - - - - - - - - - - - - - -
2,3,4-Triacetyl-3-l-rhamnose--- - - - - - - - - - -
1,2,3,4-Tetraacetyl-3-l-rhamnose-- - - - - - ---
1, 1’,2,3,4,5-Hexaacetyl-l-rhamnose— — — — . . .
1,2-[l-Rhamnose] methyl orthoacetate ---
1,2-[3,4-Diacetyl-l-rhamnose ] me thy l
Orthoacetate.
1-Chloro-2,3,4-triacetyl-o'-l-rhamnose------
1-Bromo-2,3,4-triacetyl-o'-l-rhamnose------
Methyl cº-l-rhamnopyranoside- - - - - - - - - - -
Methyl 3-l-rhamnopyranoside - - - - - - - - - -
Methyl 2,3,4-triacetyl-o'-l-r h a m n O p y –
ranoside.
Methyl 2,3,4-triacetyl-3-l-rh a m n O p y -
ranoside.
Methyl 2,3,4-trimethyl-3-l-rh a m n opy -
ranoside.
Methyl 2-acetyl-3,4-dimethyl-3-l-rham-
nopyranoside.
Methyl 5-methyl-o'-l-rhamnofuranoside---
Monoacetone-l-rhamnose-I. - - - - - - - - - - - - -
Monoacetone-l-rhamnose-II- - - - - - - - - - - - -
l-Rhamnonic 6-lactone_--_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
l-Rhamnonic Y-lactone - - - - - - - - - - - - - - - - -
[15]
[13] .
[5, 16]
[13]
| 13, 17]
[13]
[12]
[12]
[11]
[11, 18]
[11, 19)
[20, 21]
[20, 21,
22, 23,
24]
[21]
[23, 25, 26]
[27]
Cs H16O;
C; H13O5
C19H18Os
C14H2009
C15H26O12
CoPH1606
C15H26Os
C12H 17O7Cl
C19H1707 Br
7 14 U.5
C;H13O;
C15H26Os
C15H26Os
C10H2005
C11H2006
CŞH16O5
CohlöO5
CoH16O;
C6H10O3
C6H10Os
C6H13O3 N
C19H18O3N2
C6H10O3
192. 21
178, 18
290. 27
332. 30
434. 39
220, 21
304, 29
308, 71
353, 17
178, 18
178. 18
304, 29
304, 29
220, 26
248. 27
192, 21
204, 22
204, 22
162. 14
162. 14
179, 17
270° 28
130. 14
91–92
102–103
96–98
98–99
72–73
140–141
83–85
73
71–72
109–110
138–140
86–87
151—152
53–54
67
59–60
87–89
79–80
172–182
149–151
134
195—196
74. 5
— 10— — — 18.6
— 4.3 (25°)
+ 28.13–3 – 18.6
+ 13.9
–7.5 (17°)
+ 10 (21°)
+35.0 (21°)
— 127.0
— 169.0
— 62.5
+95.4
— 53.7 (16°)
+ 45.7 (18°)
+ 106 (21°)
––36
–89.2 (23°)
+ 134— — — 17.8
+ 10, 650
—39, 210
–59, 690
– 11, 140
+ 17, 000
— 16, 340
+ 13, 910
+23, 350
+8, 940
– 17, 150
H2O
H2O
EtOH
C2H2Cl4
MeOH
EtOH
CHCl3
CHCla
C2H2Cl4
#5
C2H2Cl;
C2H3Cl4
H2O
H2O
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
l-Rhamnonic amide - - - - - - - - - - - - - - - - - - -
l-Rhamnonic phenylhydrazide--- - - - - - - - -
l-Rhamnal------------------------ - - - -
2 Rotation after 30 minutes.
3 Rotation after 10 minutes, in absolute alcohol.
4 Rotation after 5 minutes.
TABLE 1.48.-Optical rotation and melting point of certain sugars and sugar derivatives—Continued
§
REFERENCES
[1] H. S. Isbell and W. W. Pigman, J. Research NBS 18, 141 (1937) RP969. [15] H. Ohle, W. Marecek, and W. Bourjau, Ber. deut. chem. Ges. 62,833 (1929).
[2] L. Berend, Ber. deut. chem. Ges. 11, 1353 (1878). 16] E. Fischer, Ber. deut. chem. Ges. 28, 1158 (1895).
3] E. L. Jackson and C. S. Hudson, J. Am. Chem. Soc. 59, 1076 (1937). [17] M. Bergmann and H. Schotte, Ber. deut. chem. Ges. 54, 1569 (1921).
4] E. Fischer, Ber, deut. chem, Ges. 29, 324 (1896). [18] P. A. Levene and I. Muskat, J. Biol. Chem. 106,761 (1934).
[5] J. Minsaas, Kgl. Norske Videnskab. Selskabs, Forh. 6, 177 (1933). 19] K. Freudenberg and A. Wolf, Ber. deut. chem. Ges. 59, 836 (1926).
6) C. L. Butler and L. H. Cretcher, J. Am. Chem. Soc. 53,4358 (1931). [20] H. S. Isbell and H. L. Frush, BS J. Research 11,649 (1933) RP613. a S
7] E. Fischer and J. Tafel, Ber, deut, chem. Ges. 20, 2566 (1887). [21] E. L. Jackson and C. S. Hudson, J. Am. Chem. Soc. 52, 1270 (1930). s:
[8] C. Tanret, Bul. Soc. chim. 27, 395 (1902). 22] E. Fischer and H. Herborn, Ber. deut, chem. Ges. 29, 1961 (1896). s
[9] E. O. von Lippmann, Ber. deut. chem. Ges. 60,161 (1927). 23] E. Votoček and L. Benes, Bul. Soc. chim. 43, 1328 (1928). S.
[10] P. A. Levene and I. Muskat, J. Biol. Chem. 105,431 (1934). [24] W. Will and C. Peters, Ber, deut. chem. Ges. 21, 1813 (1888). 6-
[11] P. A. Levene and J. Compton, J. Biol. Chern. 114, 9 (1936). 25] E. ºf ischer and R. S. Morell, Ber. deut. chem. Ges. 27, 390 (1394). s
12] W. N. Haworth, E. L. Hirst, and E. J. Miller, J. Chem. Soc. 1929, 2469. 26] C. S. Hudson, J. Am. Chem. Soc. 39, 462 (1917).
13] E. Fischer, M., Bergmann, and A. Rabe, Ber. deut. chem. Ges. 53,2362 (1920). (27] M. Bergmann and H. Schotte, Ber. deut. chem. Ges. 54, 440, 1569 (1921). ‘S,
14] N. W. Pirie, Biochem. J. 30, 374 (1936). - *
S-
H H H 2.
d–RIBOSE CH3OH−C——C—C——CHO S.
S’
OH OH OH s
*- : – - - - - - ------- - - - - -- ‘sº
SS
Refer- º Molec- || Melting 20 ! }} | . Concen- s
Substance €1) CeS Formula ular point [o] [M] tration Solvent s
- - --- - ----------- -------- - - ------. --- , S.
. oC g/100 ml - g
d–Ribose-- - - - - - - - - - - - - - - - - - - - - - 1, 2] C5H10O3 - 150. 13 87 — 23.1— — 23.72 (19) — 3, #79 4| H2O s
d-Ribose p-bromphenylhydrazone. [2, 3,4] C11H15O1N3 Br 319. 17| 164 + 10.3 (23°) + 3, 290 1| Abs. EtOH S-
2,3,4-Trimethyl 3-d-ribose. -- - - - - - [5] Cs H16O; 192. 21 85–86 – 51.7— — 40.0(27°) —9, 940 1| H2O s
Tetraacetyl-d-ribose_-_ _ _ _ _ _ _ _ _ _ _ ] [6] C18H18O, 3.18. 28, 110 — 52.0 (24°) — 16, 550 3. CHCl, $.
1,2-[Diacetyl-d-ribosel methyl [6] C12H18Os 290. 26 77–78 + 2.4 (26°) + 700 1 CHCl,
Orthoacetate
1-Bromo-triacetyl-d-ribose - - - - - - - [6] C11H15O1 Br 339. 15 96 –209.3 (25°) –70, 980 2 CHCl,
Methyl d-riboside----- - - - - - - - - - - [7] 6H12 5 164. 16 83–84 – 113.6 — 18, 650 1. Hg
d–Ribonic lactone_-- - - - - - - - - - - - - [8] C5H8Os 148. 11 77 ------------------|-------- -------------------

§
[1]
2
3.
[4]
[5]
[6
[7]
[8]
[9.
10.
11
12
[13
[14
[15]
OH OH OH
l-RIBose CH2OH−–C–C––C—CHO
H H H
l-Ribose--- - - - - - - - - - - - - - - - - - - - - [1, 9, 10] | C5H10O3 150. 13| 87 +20.3— — — 20.7% + 3, 050 4| H2O
l-Ribose p-bromphenylhydrazone. [3, 10] C11H15O4N2Br 319. 17| 164–165| + 21.9 (30°) |_ _ _ _ _ _ _ . 1| Pyridine
l-Ribonic acid-- - - - - - - - - - - - - - - - - [11] C5H10O6 166. 13| 104–105 -- 17.6— — 4.6 + 2, 920 3 H2
l-Ribonic lactone--------- - - - - - - -] [12, 13] C5H8O; 148. 1 79–80 — 18.0 –2, 660 9| H2O
l-Ribonic amide------- - - - - - - - - - - | [14, 15] C5H1105N 165. 15| 137–138|| — 16.4 –2, 710 3| H2O
l-Ribonic phenylhydrazide - - - - - - [12] C11H16O5N2 256. 26|| 162–164|_ _ _ _ _ _- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
* Complex mutarotation.
REFERENCES
F. P. Phelps, H. S. Isbell, and W. W. Pigman, J. Am. Chem. Soc. 56, 747 (1934).
A. van Ekenstein and J. Blanksma, Chem. Weekblad 10, 664 (1913).
P. A. Levene and R. S. Tipson, J. Biol. Chem. 115, 731 (1936).
E. Cherbuliez and K. Bernard, Helv. Chim. Acta 15, 464, 978 (1932).
P. A. Levene and R. S. Tipson, J. Biol. Chem. 93, 623 (1931); 94,809 (1932).
P. A. Levene and R. S. Tipson, J. Biol. Chem. 92, 109 (1931).
J. Minsaas, Liebigs Ann. Chem. 512, 287 (1934).
M. Steiger, Helv. Chim. Acta 19, 189 (1936).
H. S. Isbell and W. W. Pigman, J. Research NBS 18, 141 (1937) RP969.
W. C. Austin and F. Humoller, J. Am. Chem. Soc. 54, 4749 (1932).
K. Rehorst, Liebigs Ann. Chem. 503, 160 (1933).
E. Fischer and O. Piloty, Ber. deut. chem. Ges. 24, 4214 (1891).
M. Gehrke and F. X. Aichner, Ber. deut. chem. Ges. 60, 918 (1927).
R. A. Weerman, Rec. trav. chim. 37, 38 (1917).
C. S. Hudson and S. Komatsu, J. Am. Chem. Soc. 41, 1141 (1919).
;
TABLE 148.-Optical rotation and melting point of certain sugars and sugar derivatives–Continued
OH. H. OH
l-SORBOSE CH2OH C C C º CH2OH
H OH H O
Molec- g r
Substance º: Formula Mla * [a]?" [M] º Solvent
weight •
--
oC g/100 ml
l-Sorbose---------------------------- 1, 2, 3]| C8H12O6 180. 16, 159–161 – 43.7— —43.42 ) — 7, 870 12| H2O
l–Sorbose p-bromphenylosa Zone – _ _ _ _ _ _ [4] C1s H2004N4Br2 516. 20, 181 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
l-Sorbose phenylosa Zone.-- - - - - - - - - - - - - - [5] C18H22O4N4 358. 39| 164 — 13 (15°) –4, 660 1 ºt
tC)H
4-Methyl-l-Sorbose-------------------- [6] C;H1406 194. 18| 133 ?— —30.9 (12°) |_ _ _ _ _ _ _ _ 2 H2O
Tetraacetyl-o'-l-SOrbose- - - - - - - - - - - - - - - - 7] C14H20010 348. 30| 100, 8 — 21.3 –7, 420 1 CHCls
Pentaacetyl-o'-l-sorbose mº m * *- - - - - - - - - - -, * * * 7] 161122\_V11 390. 34 97 — 56.5 –22, 050 1 CHCla
Pentaacetyl-3-l-Sorbose- - - - - - - - - - - - - - - - 7] 16 Ll22\_J11 390. 34 113. 8 + 74.4 +29, 040 1 CHC13
Pentaacetyl-keto-l-Sorbose- - - - - - - - - - - - - (8,9] 16 Ll22\J11 390, 34| 99 +2.8 (X = 578) |_ _ _ _ _ _ _ _ 5 CHCl3
2-Chloro-tetraacetyl-o'-l-SOrbose - - - - - - - - 7] C14H10O3Cl 366. 75|| 67 — 83.3 –30, 550 1 CHCla
Methyl ox-l-Sorboside- - - - - - - - - - - - - - - - - - [7, 10, ] C;H1406 194. 18| 119 — 88.7 – 17, 200 2| H2O
11, 12
+ 39.0 + 7, 570 2 º
Methyl 3-l-Sorboside- - - - - - - - - - - - - - - - - - [7] C7H1406 194. 1s 106.2 {{# #. 3 ºf
+ 101.4 + 19, 690 1| Ethylace-
tate.
Methyl tetraacetyl-o'-l-Sorboside - - - - - - - - [7] C15H22O10 362. 33| 89. 5 — 52.6 – 19, 060 1 CHCla
Methyl tetraacetyl-3-l-sorboside- - - - - - - - [7] 15-LL22\_/10 362. 33| 75 –|- 79.8 +28, 910 1 CHCla
Monoacetone-l-SOrbose- - - - - - - - - - - - - - - - [13] 911 16V M76 220. 22 92–93 |----------------|--|--|--|--|- - - - - - - - - - - - - - - - - -
- - - - - - - - [13] C12H2006 260. 28| 77–78 – 19 –4, 950 1| H2O
Diacetone-l-Sorbose- - - - - - - - - - -
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
2 Small complex mutarotation.
3.
REFERENCES
[1] W. W. Pigman and H. S. Isbell, J. Research NBS 19, 443 (1937) RP1035.
[4] C. Neuberg and F. Heymann, Chem. Zentr. 1902, I, 1241.
2] H. H. Schlubach and J. Vorwerk, Ber. deut. chem. Ges. 66, 1251 (1933).
3] R. Smith and B. Tollens, Ber. deut. chem. Ges. 33, 1285 (1900).
[5] E. Fischer, Ber. deut. chem. Ges. 20, 827. (1887); E. G. V. Percival, J. Chem. Soc. 1938, 1384.
[6] W. Bosshard and T. Reichstein, Helv. Chim. Acta 18, 959 (1935).
[7] H. H. Schlubach and G. Graefe, Liebigs Ann. Chem, 532, 211 (1937).
[8] G. Arragon, Compt. rend. 196, 1733 (1933).
[9] F. B. Cramer and E. PacSu, J. Am. Chem. Soc. 59, 1467 (1937).
[10] E. Fischer, Ber. deut. chem. Ges. 28, 1159 (1895).
[11] C. A. Lobry de Bruyn and W. A. van Ekenstein, Rec. trav. chim. 19, 1 (1900).
[12] G. Arragon, Compt, rend. 199, 1231 (1934).
[13] S. Maruyama, Sci. Pap. Inst. Phys. Chem. Res. (Tokyo) 27, 56 (1935).
sucrose ((d-glucopyranosido)-d-fructofuranoside)
Molecu- ſº
Refer- Melting 20 1 A Concen- yº
Substance €I) CéS Formula wº point [o]}} [M] tration Solvent
oC g/100 ml
Sucrose---------------------------------- 1, 2] C12H22O11 342. 30, 1882 +66.53 +22, 770 26 H2O
Octaacetylsucrose----- - - - - - - - - - - - - - - - - - - - - - [3, 4) 28il 38WCW 19 678. 59, 692 + 59.6 +40, 440|_ _ _ _ _ _ _ _ CHCla
Sucrose octanitrate - - - - - - - - - - - - - - - - - - - - - - - - 5, 6] C12H14027Ns 702. 29 85. 5 + 55.9 +39, 260 3| MeOH
Octapalmitylsucrose - - - - - - - - - - - - - - - - - - - - - - - [7] C140H282O16 2249, 52 54–55 || -- 17.1 +38, 470 4 CHCl3
Octastearylsucrose--- - - - - - - - - - - - - - - - - - - - - - - [7] 1561.1294 2473. 94 57 + 16.6 +41, 070 8| CHCl3
Octacinnamoylsucrose-- - - - - - - - - - - - - - - - - - - - - [8] 841-170\_V19 1383. 41 87–88 + 12.5(18°) |+ 17, 290 3| CHCl3
Sucrose monophosphate. --- - - - - - - - - - - - - - - - - 9, 10] 12 Ll 23\J 14 422. 33 Sirup| –-85.1 * * * * = - - - 2 H2O
Heptamethylsucrose_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ [11] 191136V11 440, 48 Sirup| ––68.5 +30, 170 6|| MeOH
Octamethylsucrose---- - - - - - - - - - - - - - - - - - - - - - 11, 12]| C20H38011 454. 51 Sirup| –-69.3 +31, 500 7| MeOH
Tritritylsucrose------------- - - - - - - - - - - - - - - - [13] 691164V 11 1069. 21 127–129 +44.3 (23°) |+47, 370 2| EtOH
Pentaacetyl-tritritylsucrose_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ [13] 79 L174 U16 1279. 39 125–126 +57 (23°) |+72, 930 1 CHCls
| These values are read at 20° C except where the temperature is specified otherwise in parentheses.
2 Crystallized from alcohol.
{ Bates and R. F. Jackson, Bul. BS 13, 125 (1916) S268.
§ Ber. deut. chem. Ges. 13, 267 (1880).
j.
º
t
. Will and F. Lenze, Ber. deut. chem. Ges. 31, 68 (1898).
:
F.
S.
A.
C.
E.
W
K
Shah and Y. M. Chakradeo, Current Sci., 4, 652 (1936).
Hudson and J. M. Johnson, J. Am. Chem. Soc. 37, 2748 (1915).
Hoffman and V. P. Hawse, J. Am. Chem. Soc. 41, 235 (1919).
. Hess and E. Messmer, Ber. deut. chem. Ges. 54, 499 (1921).
Melting point depends upon solvent used in crystallization, (Helv. Chim. Acta 11, 901 (1928); 13, 698 (1930)).
REFERENCES
[8] S. Oden, Arkiv. Kemi, Mineral, Geol. 7, No. 15 (1918).
[9] C. Neuberg, Z. Ver. deut. Zucker-Ind. 76, 463 (1926).
[11] W. N. Haworth, J. Chem. Soc. 107, 8 (1915).
[12] T. Purdie and J. C. Irvine, J. Chem...Soc. 87,1022 (1905).
[13] K. Josephson, Liebigs Ann. Chem. 472, 230 (1929).
| O. Meyerhoff and K. Lohmann, Biochem. Z. 185, 113 (1927).
3.
TABLE 148.—Optical rotation and melting point of certain sugars and sugar derivatives–Continued
H OH OH OH
d-TALOSE CH2OH C C C—C——CHO
OH H H H
Molec- & ºt
* Refer- * Melting 20 1 J()I) C62]] - Solvyc
Substance €l) CeS Formula wº point [o]% [M] tration Solvent
oC g/100 ml
o:-d-Talose- - - - - - - - - - - - - - - - - - - - - - - - - - - - 1, 2, 3]| C6H12O6 180. 16. 133–134 + 68.0— -- 20.8 |-|- 12, 250 4 H2O
B-d-Talose- - - - - - - - - - - - - - - - - - - - - - - - - - - - [3] C6H12O6 180. 16 120–121 | + 13.2— --21.0 | + 2, 380 4 H2O
d-Talose methylphenylhydrazone- - - - - - - - (2, 4) C15H26O;N3 284. 31|| 154 |_ _ _ _ _ _ = - - - - - - - -- I - - - - - - - - - *-* ---. --- - - - - - - -
2,3,4,6–Tetraacetyl-o-d-talose----- - - - - - - -] [3] C14H20010 348. 30. 112–113 | + 42.8 + 14, 910 2 CHCla
1,2,3,4,6-Pentaacetyl-o-d-talose-- - - - - - - - - [3] C18H22O11 390. 34 106–107 || -- 70.2 +27, 400 4 CHCla
1-Bromo-2,3,4,6-Tetraacetyl-o-d-talose - - -] [3] C14H10O8Er 411. 21 84 + 165.6 +68, 100 4 CHCla
l,2-[3,4,6-Triacetyl-d-talose] methyl or- 3] C15H22O10 362. 33| 91. 5–92. 5 ––3.7 + 1, 340 3 CHCla
thoacetate
1,2-d-Talose Orthobenzoic acid -- - - - - - - - - - [3] C18H16O7 284. 26, 150–1700. --21.2 +6, 920 0.4| H2O
d-Talonic acid---- - - - - - - - - - - - - - - - - - - - - - [5] C6H12O7.%.H2O 205. 17| 138 + 19.0 (25°) +3, 900 4 H2O
d-Talonic Y-lactone - - - - - - - - - - - - - - - - - - - - 5, 6] C6H10O6 178. 14| 132–134 – 34.7 (25°) — 6, 180 2 H2O
d-Talonic amide - - - - - - - - - - - - - - - - - - - - - - - [7] C6H13O8 N 195. 17| 121 – 13.1 (25°) –2, 560 2 H2O
d-Talonic phenylhydrazide--- - - - - - - - - - - - (8, 9] C19H18O8 No 286. 28, 159 – 25.4 (25°) –7, 270 3 H2O
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
REFEREN C F S
[1] H. S. Isbell and W. W. Pigman, J. Research NBS 18, 141 (1937) RP969.
2) P. A. Levene and R. S. Tipson, J. Biol. Chem. 93, 631 (1931).
3] W. W. Pigman and H. S. Isbell, J. Research NBS 19, 189 (1937) RP1021.
4] J. Blanksma and W. A. van Ekenstein, Chem. Weekblad 5, 777 (1908).
§ L. H. Cretcher and A. G. Renfrew, J. Am. Chem. Soc. 54, 1590 (1932).
6] H. T. Bonnett and F. W. Upson, J. Am. Chem. Soc. 55, 1245 (1933).
7] A. G. Renfrew and L. H. Cretcher, J. Am. Chem. Soc. 54, 4402 (1932).
8] Q. Hedenburg and L. H. Cretcher, J. Am. Chem. Soc. 49, 478 (1927).
9] E. Fischer, Ber. deut. chem. Ges. 24, 3622 (1891).
s:
TREHALOSE (o:-(o-d-glucopyranosido)-d-glucopyranoside)
Molec- º
Substance º: Formula ..., * [a]% [M] º: Solvent
weight
- oC g/100 ml | .
Trehalose.2H2O * *m sºm ºn “ ºr *-* * * *- - - - - *** - - - - mº - - - ºr- sº me • *- * * ſ 1 | C12H26O13 378. 33 97 + 178.3 + 67, 460 7 H2O
Hexaacetyltrehalose--------------------------- [2] C24 H34017 594. 52 93–96 -- 159 (19°) + 94, 530 3| CHCl2
Octaacetyltrehalose * * * * * * * - * * * * * *-* - - - * * m - m. m a.º. -- * *- [3, 4] 281. L38 U19 678. 59 98 + 162.3 + 110, 140 10 CHCls
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
|REFERENCES
[1] I. Schukow, Z. Ver. deut. Zucker-Ind. 50, 818 (1900).
[2] H. Bredereck, Ber. deut. chem. Ges. 63, 959 (1930).
[3] L. G. M. Maquenne, Compt. rend. 112, 947 (1891).
[4] C. S. Hudson and J. M. Johnson, J. Am. Chem. Soc. 37, 2748 (1915).
;
TABLE 148.-Optical rotation and melting point of certain sugars and sugar derivatives—Continued
TURANOSE (3-(o-d-glucopyranosido)-d-fructose)
Molec- g "or, a
Substance º: Formula wº * [a]}' [M] º Solvent
reight
- oC g/100 ml
Turanose------------------------------ | 1, 2, 7]| C12H22O11 342. 30, 157 +27.3— -- 75.8 +9, 340 4| H2O
Heptaacetylturanose-------------------- [3] C28H38O18 636. 55| 1.47 +38.7— +41.7 +24, 630 2| CHC13
Octaacetylturanose I-------------------- [4] C28H38019 678. 59, 216–217| +20, 5 + 13, 910 4| CHCl3
Octaacetylturanose II-- - - - - - - - - - - - - - - - - - [4, 5 C28H38O16 678. 59| 158 + 107.0 +72, 610 1 CHCla
Octaacetyl-keto-turanose III-- - - - - - - - - - - - [4, 6] C28H38O16 678. 59| 96 + 126.2 +85, 640 6| CHCl3
Octaacetylturanose IV - - - - - - - - - - - - - - - - - - [4, 5 | C28H38O16 678. 59| 194–195 –– 103.2 +70,030 3| CHCl3
1,2-Turanose methyl orthoacetate- - - - - - - - [3] C15H26O12 398. 36|| 137 + 114. 6 +45, 650 1| H2O
1,2-[Hexaacetylturanose] methyl orthoace- | [3] C27H33Ois 650. 58 162–164|| -- 80 +52, 050 3| CHC13
tate.
2-Chloro-heptaacetylturanose- - - - - - - - - - - - [4] C26H35017Cl 655. 00. 165 — 0.44 — 290 6| CHCla
2–Bromo-heptaacetylturanose- - - - - - - - - - - - [4] C26H35017 Br 699. 46|| 133–134 — 30.5 –21, 330 5| CHCla
2-Iodo-heptaacetylturanose_ _ _ _ _ _ _ _ _ _ _ _ _ _ [4] C26H35017 I 746, 46. 105–106 – 54. 2 –40, 460 4| CHCla
Methyl heptaacetyl-3-turanoside - - - - - - - - - 3] C27H3301s 650. 58, 188–189| ––27. 5 + 17, 890 2 CHCl,
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
REFERENCES
[1] C. S. Hudson and E. Pacsu, J. Am. Chem. Soc. 52, 2519 (1930).
É H. S. Isbell and W. W. Pigman, J. Research NBS 20, 773 (1938) RP1104.
[3] E. PacSu, J. Am. Chem. Soc. 55, 2451 (1933).
É E. PacSu, J. Am. Chem. Soc. 54, 3649 (1932).
[5] F. B. Cramer and E. Pacsu, J. Am. Chem. Soc. 59, 711 (1937).
[6] E. PacSu and V. Rich, J. Am. Chem. Soc. 55, 3018 (1933).
[7] H. S. Isbell, J, Research NBS 26, 35 (1941) RP1356.
§
d-xYLOSE CH2OH−—C—C—C—CHO
OH. H. OH
Molec- †
Refer- Melting 20 ! V Concen- y
Substance €I) CeS Formula ular point [o]}} [M] j| Solvent
weight
oC g/100 ml
o-d-Xylose-------------------------- 1, 2] C5H10O5 150. 13| 1.45 + 93.6— + 18.8 + 14, 0.50 4| H2O
d-Xylose 8-naphthylhydrazone.--------- [3] C15H18OAN2 290, 31 124 |-----------------------------------|--------
d-Xylose phenylosazone- - - - - - - - - - - - - - [4, 5 J 17 L120V3 328. 36|| 160–161|- - - - - - - - - - - - - - - - - - - - - - - - - --|--|--|--|--|--------
3-Methyl-o-d-xylose--...--------------- [6] 6Ll 12V5 164. 16| 103–104 -- 52.2— -- 14.8 +8, 570 2 H2O
2-Methyl-3-d-xylose------------------ [7] C6H12O5 164, 16 132–133 — 23.9— — — 35.9 –3, 920 4| H2O
Trimethyl-o'-d-xylose---- - - - - - - - - - - - - - [8] 8 L.L 16V5 192. 21| 91–92 | + 64.5— + 17.7 + 12, 400 1| H2O
5-Thiomethyl-o'-d-xylose--- - - - - - - - - - - - [9] 6LL 12V-J 4 180. 22 74–75 | +36.4— — —20.6 + 6, 560 2| H2O
2,3,4-Triacetyl-d-xylose--- - - - - - - - - - - - - [10] C11H18O8 276. 24| 138–141 + 70.4—3 + 40, 8(21°)|_ _ _ _ _ _ _ _ 2| CHCl3
2,3,4,5-Tetraacetyl-aldehydo-d-xylose----| [11] C18H18O3 318. 28' 87–89 | – 15.9 (26°) —5,060 4. CHCl3
1,2,3,4-Tetraacetyl-o-d-xylose- - - - - - - - - [14] C18H18Oo 31.8. 28' 59 + 89.3 +28, 400 5| CHCl3
1,2,3,4-Tetraacetyl-3-d-xylose- - - - - - - - - [12, 13, C18H18O3 318, 28|| 128 — 24.7 –7, 860 5| CHCl3
14]
Hexaacetyl-d-xylose--- - - - - - - - - - - - - - - - [15] C17H24O12 420. 36|| Sirup - - - -4.0 (17°) |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ CHCl3
1-Fluoro-2,3,4-triacetyl-o'-d-xylose------ [16] 11H15O; 278. 23. 87 + 67.2 + 18, 700 2 CHCl3
1-Chloro-2,3,4-triacetyl-o-d-xylose- - - - - [14, 17, C11H15O; Ci 294, 69| 105 + 171.2 +50, 450 2| CHCl3
18] \
1-Chloro-2,3,4-triacetyl-3-d-xylose------ [19] C11H15O1Cl 2.94. 69 112–113 — 131.0 (23°) –38, 600 1| CCl3
1-Bromo-2,3,4-triacetyl-o'-d-xylose- - - - - [14, 18, C11H15OFBr 339. 15| 101-102 + 211.9 +71, 870 2 CHCl3
20)
Methyl ox-d-xylopyranoside------- - - - - - [21, 22]| C6H12O5 164. 16| 90–92 | + 153.9 +25, 260 11| H2O
Methyl 3-d-xylopyranoside------- - - - - - [21, 22 || C6H12O5 164. 16| 157 — 65.5 — 10, 750 13| H2O
Methyl 2,3,4-triacetyl-o-d-xylopyrano- | [10] C12H18O8 290. 27| 86 + 119.6 +34, 720 4| CHCl3
side
Methyl 2,3,4-triacetyl-3-d-xylopyrano- | [14, 201| C19H18Os 290. 27. 115 — 60.8 — 17, 650 2 CHCl3
side
H OH H
1 These values are read at 20°C except where the temperature is specified otherwise in parentheses.
3.
TABLE 148.-Optical rotation and melting point of certain sugars and sugar derivatives—Continued
H OH. H.
d-xylose I CH3OH−C–C–C–CHO
OH H OH
Molec- & N
Substance ... Formula || i. º.º. [...]?' | [M] ºr solvent
- weight
oC g/100 ml
Methyl trimethyl-3-d-xylopyranoside---| [8] Coh 18O; 206. 24|| 51 —- 69.5 – 14, 330 1 CHCls
Methyl 3,4-dimethyl-3-d-xylopyranoside [7] CŞH16O5 192. 21 | 89–90 | – 82.2 — 15, 800 2| CHCl3
Methyl 2,4-dimethyl-8-d-xylopyranoside [7] s}{16Os 192. 21 | 60–61 | – 82.4 — 15, 840 1| CHCla
Methyl 2-methyl-3-d-xylopyranoside---| [7 C; H 1405 178. 18 111–112| – 67.7 — 12, 160 1 CHCla
1,2-Monoacetone-d-xylosell--. -- - - - - - - [23, 24 || C8H13O5 190. 19 41–43 | – 19.0 (18°) –3, 610 2–4| H2
Diacetone-d-xylose-- - - - - - - - - - - - - - - - - - [23, 25 || C11H18O3 230, 26 44–45 + 13.0 (22°) +2, 990 2 H2O
d-Xylonic Y-lactone------- - - - - - - - - - - - [26, 27, 5.L.I.SV5 148. 11 98– 101| + 91.8 + 13, 600 5| H2O
28, 29]
Cadmium d-xylonate. Cabrº.2H2O------| [30, 31 || Cich 2901, Cd, Br, 750. 93|_ _ _ _ _ _ _ _ +8.8 +6, 610 1| H2O
d-Xylonic amide---------- - - - - - - - - - - - [32] C5H1105.N 165. 15| 81–82 | +44.5 (16°) + 7, 350 9| H2O
d-Xylal (d-lyxal) - - - - - - - - - - - - - - - - - - - - - [33, 34 || C5H8O3 116. 11| 49–50 | – 254.5 (26°) |–29, 550 2 H2O
1 These values are read at 20° C except where the temperature is specified otherwise in parentheses.
REFEREN C FS
[9] A. L. Raymond, J. Biol. Chem. 107, 85 (1934).
j G. J. Robertson and T. H. Speedie, J. Chem. Soc. 1934,824.
| F. P. Phelps and C. B. Purves, J. Am. Chem. Soc. 51, 2443 (1929).
1]. H. S. Isbell and W. W. Pigman, J. Research NBS 18, 141 (1937) RP969.
2 C. N. Riiber and O. Bjerkli, Kgl. Norske Videnskab. Selskabs, Skrifter, No. 5 (1936).
3] A. Hilger and S. Rothenfusser, Ber. deut. chem. Ges. 35,4444 (1902).
4] T. Reichstein, A. Grüssner, and R. Oppenauer, Helv. Chim. Acta 16, 1024 (1933).
; H. I. Wheeler and B. Tollens, Liebigs Ann. Chem. 254, 304 (1889).
6] P. A. Levene and A. L. Raymond, J. Biol. Chem. 102, 331 (1933).
7
8
9
[10] C. S. Hudson and J. K. Dale, J. Am. Chem. Soc. 40, 997 (1918).
[11] M. L. Wolfrom, M. R. Newlin, and E. E. Stahly, J. Am. Chem. Soc. 53, 4379 (1931).
12] W. E. Stone, Am. Chem. J. 15,653 (1893).
13] R. Bader, Chem. Ztg. 19, 55 (1895).
3.
ſ34
C. S. Hudson and J. M. Johnson, J. Am. Chem. Soc. 37, 2748 (1915).
N. W. Pirie, Biochem. J. 30, 374 (1936).
. H. Brauns, J. Am. Chem. Soc. 45,833 (1923).
. Ryan and G. Ebrill, Proc. Roy. Dublin Soc. 11, 249 (1905–1908).
g # Brauns, J. Am. Chem. Soc. 47, 1280 (1925).
. K.
. F
Dale, J. Am. Chem. Soc. 37, 2746 (1915).
ischer, Ber. deut. chem. Ges. 28, 1145 (1895).
. S. Hudson, J. Am. Chem. Soc. 47, 265 (1925).
. A. Levene and A. L. Raymond, J. Biol. Chem. 102, 317, 331 (1933).
. Svanberg and K. Sjöberg, Ber, deut. chem. Ges. 56,863 (1923).
. A. Levene and R. S. Tipson, J. Biol. Chem. 115, 731 (1936).
. S. Isbell and H. L. Frush, BS J. Research 11,649 (1933) RP613.
. Hasenfratz, Compt. rend. 196, 350 (1933).
. W. Nef, Liebigs Ann. Chem. 403, 252 (1914).
H. A. Clowes and B. Tollens, Liebigs. Ann. Chem. 310, 176 (1900).
. Hudson and H. S. Isbell, J. Am. Chem. Soc. 51, 2225 (1929).
Bertrand, Bul. Soc. chim. [3] 5, 554 (1891) # 19, 1001 (1898).
G
;
#
. U
Š
* Weerman, Rec. trav. chim. 37, 40 (1917)
Levene and T. Mori, j. Biol. &hem. 83,803 (1929).
ehrke and F. Obst., Ber. deut. chem. Ges. 64, 1724 (1931).
;
M
Schlubach and R. Gilbert, Ber, deut. chem. Ges. 63,2292 (1930).
§
TABLE 149.-Optical rotation and mutarotation of the reducinq sugars
Heat of activation
for mutarotation
COnstant 1
Mutarotation:
[o]p at t minutes after solution=
AX 10-mit-H BX 10-m2t +2C
& a s Mutarotation Change due
Initial Onstants to— Refer-
Sugar Conc. Temp. specific Solvent COI) S103. Equilib-lences
rotation . cº, rium
rea,C UlOIn I’ IOIl e
Slow Fast Slow Fast rotation
reaction reaction reaction reaction
Q Q *m; *m2 A B C
1 2 3 4 5 6 7 8 9 10 11 12 13
g/100
ml o C ſold kcal kcal ſold ſold [o] d -
6-l-Arabinose------------ 4. 3 20. 0 |-|- 190. 6 16. 8 14. 7 | H2O - - - - - 0. 0300 0. 138 |+77. 3 || --8.8 |+ 104.5 | [1]
Do----------------- 4. 1 0. 0 |-|- 194. 0 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2\-7 - - - - - , 0.0362 0217 |-|-78.9 || --5.9 |+109. 2 | [1]
o:-l-Arabinose. CaCl2.4H2O- 8. 9 || 20. 0 +34. 7 16. 3 12. 1 | H2O - - - - - 0300 169 |–16. 8 || +3. 5 +48. 0 | [1]
Do----------------- 9. 3 0. 0 | +35. 4 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2\’ — — — — — 0.0384 0369 |–16. 8 || --2. 1 || --50. 1 | [1]
o:-d–Lyxose-------------- 4. 0 20. 0 + 5. 6 15. 3 –------- H2O - - - - 0.568 |_ _ _ _ _ _ _ _ + 19. 4 |_ _ _ _ _ _ .. — 13. 8 | [1]
Do----------------- 3. 9 0. 2 +4. 7 --------|-------- H2O------ 00844 |_ _ _ _ _ _ _ _ +18. 1 |_ _ _ _ _ _ .. – 13.4 | [1]
6-d-Lyxose-------------- 4. 0 20. 0 | — 72. 6 15. 7 -------- H2O - - - - - 0591 |_ _ _ _ _ _ _ _ — 58. 8 |_ _ _ _ _ _ .. — 13.8 [1]
Do----------------- 4. 0 0. 2 | – 70.8 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ H2O - - - - - 00840 |_ _ _ _ _ _ _ _ –57. 4 - - - - - - .. — 13. 4 || || 1 ||
l-Ribose- - - - - - - - - - - - - - - - 4. 0 20. 0 || +20. 3 15. 8 11. 7 | H2O - - - - - . 04.92 231 —7. 6 + 7. 2 | +20. 7 | [1]
Do----------------- 4. 1 0.2 | +23. 4 - - - - - - - - - - - - - - - - H2O - - - - - 00687 054 –7. 9 +8. 1 || +23. 2 | [1]
o:-d-Xylose-------------- 4. 4 20. 0 || --93. 6 16. 8 ||-- - - - - - - H2O_ _ _ _ _ 0203 |_ _ _ _ _ _ _ _ +74. 8 |_ _ _ _ _ _ _ +18.8 [1]
Do----------------- 4. 2 0. 0 | +95. 2 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ H2O - - - - - 00245 |_ _ _ _ _ _ _ _ +77. 9 |_ _ _ _ _ _ _ + 17.3 | [1]
o:-l-Rhamnose. H3O-- - - - - - 4. 0 20. 2 — 8. 6 15. 9 |- - - - - - - - H2O - - - - - . 0430 |- - - - - - - - — 16. 8 |_ _ _ _ _ _ _ +8. 2 | [1]
O---- - - - - - - - - - - - - - 4. 5 0. 0 -7. 4 ---------------- H2O - - - - - 00568 |_ _ _ _ _ _ _ _ – 16. 1 |- - - - - - - +8. 7 | [1]
3.
8-d-6-Galaheptose--- - - - - -
ºdºglucoheptoe. - 4- - - - -----
o:-d-o-Mannoheptose.H2O -
See footnotes at end of table.
— 15.2. 6
Buffer 25
. 02:27
. 00290
. 0254
. 00359
. 00803
. 000930
Öóð897
000711
. 50
i
ſ
:ſ
E
}*
;
ſ
:º
2
.-
*
:
|
:-
3.
TABLE 149.-Optical rotation and mutarotation of the reducing sugars—Continued
Heat of activation
for mutarotation
Mutarotation:
[o] D at t minutes after solution =
Constant 1 AX 10-mit-H BX 10-mit--2C
tº a tº Mutarotation Change due
Initial
Sugar Conc. Temp. specific Solvent COnstants to— Equilib . -
rotation|, i..., n. rium
Tëa,Ct. I'68, CUIOI). : ~~
Slow Fast Slow Fast rOtation
reaction reaction reaction|reaction
() () *m; *m2 A B C
1 2 3 4 5 6 7 8 9 10 11 12 13
g/100
ml o C ſold kcal kcal [o]p ſold ſold
8-d-o-Mannoheptose.H2O - 4. 0 20. 0 | +42. 3 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ H2O - - - - - 00384 . 048 –25. 1 | +2.9 | +64. 5 [5]
o-d-6-Mannoheptose. H2O - 4. 0 20. 0 | +45. 7 16, 4 13. 2 2O----- 0.141 0916 +8. 3 |+22.9 || -- 14.5 | [9]
Po----------------- 4. () 0. 1 | +45. 1 |- - - - - - - - - - - - - - - - 2O.----- 00181 01:59 || --9. 3 |+ 19. 3 | + 16.5 | [9]
8-Cellobiose-- - - - - - - - - - - - 7.7 19. 9 || -- 14. 2 17, 3 |- - - - - - - - Buffer 14 00461 |_ _ _ _ _ _ _ _ –20. 4 |_ _ _ _ _ _ _ +34. 6 | [2]
Do--------------- * * 3. 3 0. 1 | + 12. 3 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ---do----- 000532|_ _ _ _ _ _ _ _ –21.5 |-|--|--|--| +33, 8 || [2]
o:-Gentiobiose.2CH3OH--- 4. 7 || 20. 0 | +21.4 16, 3 |-------- ---do----- 00505 |_ _ _ _ _ _ _ _ + 12. 7 |- - - - - - - +8. 7 | [2]
0----------------- 4. 3 0 2 | +22. 1 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ---do----- 000666|_ _ _ _ _ _ _ _ + 13. 3 |- - - - - - - +8. 8 || [2]
o:-4-3-Glucosido-mannose. 5. 4 20. 0 | + 14.6 18. 2 |_ _ _ _ _ _ _ _ H2O_ _ _ _ _ 0.162 |_ _ _ _ _ _ _ _ +8. 7 |_ _ _ _ _ _ _ + 5. 9 [10]
O.
2V
Do----------------- 3. 8 0. 2 | + 16. 1 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ H2O_ _ _ _ _ 00.169 |_ _ _ _ _ _ _ _ +9. 5 |_ _ _ _ _ _ _ +6.6 [6]
6-4-3-Glucosido-mannose- 3. 5 20. 0 -6, 5 --------|-------- H20---------------------|-------------- + 6. 5 | [11]
o:-Lactose.H2O.---------- 7. 6 20. 0 || --85. 0 17, 3 - - - - - - - - H2O - - - - - 00471 |_ _ _ _ _ _ _ _ + 32. 4 |_ _ _ _ _ _ _ + 52.6 | [1]
Do----------------- 4. 9 0. 2 | +86. 4 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ H2O_ _ _ _ _ 000544|_ _ _ _ _ _ _ _ +32. 8 |_ _ _ _ _ _ _ +53. 6 | [1]
8-Lactose--------------- 4. 0 20. 0 | +34.9 17. 6 |_ _ _ _ _ _ _ _ H2O_ _ _ _ _ 00466 –20. 5 - - - - - - - + 55.4 [1]
3.
* mass mºms - *
O
*mm - - -
|
+36. 3
+ 111. 7
+ 114. 8
+ 111. 7
+ 110. 5
+33. 8
+36. 1
— 11. 9
— 10. 7
— 132. 2
— 132. 9
—43. 7
—43. 6
––27. 3
+27.8
Buffer 2 5
. 000524
. OO527
. 000580
. OO863
+ 56.
+ 130.
+ 131.
–– 129.
+ 127.
+35.
+37.
— 50.
—56.
—92.
— 103.
—43.
—43.
––75.
+70.
|
!-
:
1 Calculated from the integrated Arrhenius equation: 2.3%loº-Hºa (# -T,
2 1. 2 / 1
1
and expressed in kilocalories.
values of my at approximately 0° and 20°C, while the values of Q for the fast reaction are calculated from the values of m2 at the same temperatures.
2 Equilibrium rotation.
3 Calculated, using logarithms to the base 10.
4 The solvent was 0.001 M acid potassium phthalate Solution having a pH of 4.4 at 20° C.
5 The solvent was prepared by adding 8.0 ml of 0.1064 N NaOH to 50 ml of 0.1000 N acid potassium phthalate and adding water to make a volume of 1 liter.
The values of Q for the slow reaction are calculated from the
The pH was 4.6
and the total molarity of the phthalate Solution was about 0.005 M.
. S. Isbell, J. Research NBS 19, 639 (1937) RP1052.
. S. Isbell, J. Research NBS 20, 97 (1938) RP1069.
. S. Isbell, BS J. Research 5, 1186 (1930) RP253.
. S. Isbell, BS J. Research 7, 1130 (1931) RP392.
H. S. Isbell and W. W. Pigman, J. Research NBS 20, 773 (1938) RP1104.
[13] W. W. Pigman and H. S. Isbell, J. Research NBS 19, 443 (1937) RP1035.
REFERENCES
[1] H. S. Isbell and W. W. Pigman, J. Research NBS 18, 178 (1937) RP969. [8] H
[2] H. S. Isbell and W. W. Pigman, heretofore unpublished measurement. [9] H
[3] H. S. Isbell and W. W. Pigman, J. Research NBS 22, 397 (1939) RP1190. [10] H
[4] W. W. Pigman and H. S. Isbell, J. Research NBS 19, 191 (1937) RP1021. [11] H
5] H. S. Isbell, J. Research NBS 18, 505 (1937) RP990. [12]
6] H. S. Isbell, heretofore unpublished measurement.
[7] H. S. Isbell, J. Am. Chem. Soc. 56, 2789 (1934).
766 Circular of the National Bureau of Standards
TABLE 150.-Corrections to be applied to saccharimetric readings of levulose solutions
when a constant normal weight is used
[Normal weight at 20° C = 18.407 g; normal weight at 25° C = 19.003 gm]

Correction Correction Correction
Polari- Polari- Polari-
zation I zation 1 zation 1
20° C. 250 C 20° C. 250 C 20° C. 25° C.
Ú Ü. Ú0 U. UU 4U +U. 04 +0.5 / (5 +0.44 +U 4/
5 +. 10 +. 11 45 . 56 . 60 80 . 38 . 40
10 . 19 . 21 50 . 57 . 61 85 . 30 . 33
15 . 28 . 30 52 . 58 . 61 90 . 21 . 23
20 . 35 . 39 55 . 57 . 61 95 . 11 . 12
25 . 42 .45 60 . 56 . 59 100 . 00 . 00
30 . 47 . 50 65 . 53 56 105 —. 11 —. 14
35 . 51 . 55 70 . 50 . 52 110 —. 20 —. 26
1 In order to avoid constant repetition of the negative sign, the polarizations of levulose are considered
positive. The positive signs in the above table indicate that the negative polarizations of levulose are to be
increased to higher negative values.
XXXVII. APPENDIX 2. RESUME OF THE WORK OF THE
INTERNATIONAL COMMISSION FOR UNIFORM METH-
ODS OF SUGAR ANALYSIS
ALExANDER HERZFELD, chairman; F. G. WIECHMANN, American Secretary
FIRST SESSION [1] HAMBURG, GERMANY, JUNE 12, 1897
1. Kinds of quartz plates to be selected.—At the start, only quartz plates of high
polarizing value shall be tested; later, however, such also as will cover the entire
scale range of saccharimeters.
2. Method of eacamination of quartz plates.—Their examination is to be conducted
in the same manner as has been done heretofore by the Commission of Trades
Chemists under guidance of the Society of the Beet Sugar Industry of the German
Empire, with the participation of the Imperial Normal Testing Bureau and the
Physical Technical Reichsanstalt.
3. Temperature to be adopted as the normal temperature for polarization.—For the
examination of quartz plates 20° C is to be chosen as the normal temperature, and
the metric liter is to be adopted. The normal weight to be adopted is hence to be
26.00 g, where 26.048 g is the normal weight valid for Mohr’s liter at the tempera-
ture 17.5° C. - -
4. Additional methods and means suggested in order to decrease differences in
polarization work.—In consideration of the well-known difficulties in sampling
bagged sugar, sampling each bag does not offer sufficient advantages to justify
a departure, in the interests of trade, from the customary method of sampling
20 bags in every 100 bags.
5. Desirability of an endeavor to introduce uniformity of analytical methods for
beet-sugar work in all countries concerned.—Such an endeavor shall be made. For
the computation of sugars, analyses shall be admissible only of such chemists as
shall have pledged themselves to execute the analysis of sugar in accordance with
the methods prescribed by the International Commission.
6. The determination of invert sugar.—The determination of invert sugar is to be
made only in solutions which have been clarified with lead solution and from which
the lead has then been removed. If volumetric determinations are made, the
amount of reduction due to the chemically pure sucrose must be deducted.
SECOND SESSION [2] VIENNA, AUSTRIA, JULY 31, 1898
1. Results of the international eacamination of quartz plates.—In general, such
examinations proved satisfactory. Certain discrepancies were undoubtedly due
to the fact that the examinations had not always been made at 20°C, as prescribed.
Reference was made to the observations of Herzfeld, Wiechmann, and Wiley
that pressures, due to varying temperatures affecting their mountings, exercise an
influence on the rotation values of fixedly mounted quartz plates and quartz
wedges. Whereas the quartz plates heretofore used—owing to the fact of their
being firmly held in their mountings—are apt to be strained when their tempera-
ture is raised, and whereas such strains cause irregularities in the polarizing values
of these plates, it was resolved that the investigation above referred to should
be repeated, making use of other quartz plates not subject to the defect mentioned.
On the motion of Messrs. Dupont and Jobin it was resolved to employ plates the
rotation values of which shall cover the entire scale of the saccharimeter, one levo-
rotatory and four dextro-rotatory plates, the thickness of which is at the same time
to be given, so that the plates shall remain serviceable when the normal weights
shall be changed. -
In determining the value of the plates there shall be employed not only the
normal temperature of 20° C but, on the motion of Messrs. Wiley and Wiech-
mann, also of 30°C, in order to take into due account the condition of warmer
countries. In employing apparatus with quartz-wedge compensation the changes
shall be studied which the saccharimeter itself suffers in consequence of variations
of temperature. As source of light there shall be employed only yellow sodium
light or light sufficiently purified by ray filters. -
Upon the motion of Dr. Hermann, of Hamburg, It was furthermore agreed to
emphasize specifically in the protocol that the commission had thus far made no
such changes in the normal weight for polariscopes which could influence the
results of polarization in the least. This had been mentioned already in the
protocol of the Hamburg session of June 12, 1897.
767
768 Circular of the National Bureau of Standards
2. Desirability of examining raw beet sugars for trade purposes according to the
7mversion method.—Those present were unanimously of the opinion that the ques-
tion should, in general, be decided in the negative. Exception should be made
Only in case of the products obtained in making sugar from molasses; with these
it was recommended to make determinations of sugar and of raffinose.
3. Discussion of applications of the Deutsche Zucker Export Vereine.—Dr. Her-
mann suggested that uniformity in analytical methods should even now be striven
for as much as possible, and the presiding officer was requested to prepare, with
the assistance of the members of the commission, a clear compilation of analytical
methods which are in vogue in the different countries, and also to prepare a résumé
of the directions which are to be followed in cases of differences in analysis.
Basing on these documents, the attempt shall be made to secure international
acceptance of a uniform method of procedure.
THIRD SESSION [3] PARIS, FRANCE, JULY 24, 1900
1. Normal sugar weight to be adopted for saccharimeters of German make when the
metric flask is used.—The Imperial Physical Technical Institute has, by its com-
munication dated October 19, 1898, called attention to the fact that an exact
conversion of the normal weight 26.048 g for Mohr’s cubic centimeters at 17.5°C
corresponds to 26.01 g (not 26.00) metric volume at 20°C, determined in air with
brass weights.
The commission decided that in consideration of the insignificance of the devia-
tion the normal weight of 26.00 g shall henceforth be adopted for 100 metric cubic
centimeters at 20°C, determined in air with brass weights.
2. Eacamination and disposal of quartz plates.—Prof. Herzfeld reported briefly
On the results of the examination of quartz plates, and the commission agreed
that these quartz plates should be divided among the nations represented. For
the United States, the plates were to be sent to the Department of Agriculture,
at Washington; for France, to the Syndicate of Sugar Manufacturers; for Belgium,
Holland, Austria-Hungary, and Russia, to the associations of sugar manufacturers
represented in the session by delegates.
3. General principles governing the adjustment of saccharameters.—On motion of
Messrs. Camuset and Saillard, the following was adopted:
“The convention declares it to be necessary that the rotation of chemically
pure Sugar be accepted as the fundamental basis in saccharimetry.
“The chemically pure sugar which is to be employed for this purpose shall
everywhere be prepared according to the same method, which is as follows
(method of the English chemists):
“Purest commercial sugar is to be further purified in the following manner: A
hot saturated aqueous solution is prepared and the sugar precipitated with abso-
lute ethyl alcohol, the sugar is carefully spun in a small centrifugal machine and
washed in the latter with some alcohol. The sugar thus obtained is redissolved
in water, again the saturated solution is precipitated with alcohol, and washed as
above. The product of the second centrifugaling is dried between blotting paper
and preserved in glass vessels for use. The moisture still contained in the sugar
is ºrmined and taken into account when weighing the sugar which is to be
used.”
The convention furthermore decided that central stations shall be designated
in each country which are to be charged with the preparation and the distribution
of chemically pure sugar. Wherever this arrangement is not feasible, quartz
plates, the values of which have been determined by means of chemically pure
sugar, shall serve for the control of saccharimeters.
Mention should be made of the fact that in the discussion on this topic it was
remarked, on the One hand, that the preparation of chemically pure sugar is not
an easy task, and that in countries having hot climates sugar is dried with diffi-
culty and hence is not stable and hardly available for transportation. Thereupon
it was pointed out that the above control, by means of chemically pure sugar,
should, as a rule, apply only to the central statio s which are to test the correct-
ness of saccharimeters; for those who execute commercial analyses, the repeated
control of the instruments is to be accomplished, now as before, by means of
quartz plates.
Concerning the working temperature, the following resolution of Mr. François
Sachs was unanimously adopted:
“In general, all sugar tests shall be made at 20° C.
“The adjustment of the saccharimeter shall be made at 20° C. One dissolves
(for instruments arranged for the German normal weight) 26.00 g of pure sugar
Polarimetry, Saccharimetry, and the Sugars 769
in a 100-metric cubic centimeters flask,” weighing to be made in air, with brass
Weights, and polarizes the solution in a room, the temperature of which is also
20° C. Under these conditions the instrument must indicate exactly 100.00.
“The temperature of all sugar solutions to be tested is always to be kept at
20° C while they are being prepared and while they are being ploarized.
“However, for those countries the temperature of which is generally higher, it
is permissible that the saccharimeters be adjusted at 30° C (or at any other
suitable temperature), under the conditions specified above, and providing that
the analysis of sugar be made at that same temperature.”
Objections were raised against the universal normal weight 20.00 g by Mr.
François Sachs as well as by Mr. Strohmer. In consequence, it was resolved not
to undertake the introduction of the same, but to adopt the resolution:
...he generai international introduction of a uniform normal weight is desir-
a D16.
It was furthermore resolved, on the basis of the proposition of Mr. Strohmer,
to observe the following rules in raw sugar analysis:
I. POLARIZATION
In effecting the polarization of substances containing sugar, half-shade instru-
ments only are to be employed.
During the operation the apparatus must be in a fixed, unchangeable position,
and so far removed from the source of light that the polarizing nicol is not warmed
by the same.
As sources of light there are to be recommended lamps with intense flame
(gas triple burner with metallic cylinder, lens, and reflector; gas lamp with Auer
burner; electric lamp; petroleum duplex lamp; sodium light).
The chemist must satisfy himself, before and after the observation, of the
correctness of the apparatus (by means of correct quartz plates) and in regard to
the constancy of the light, he must also satisfy himself as to the correctness of
the Weights, of the polarization flasks, the observation tubes, and the cover glasses.
(Scratched cover glasses must not be used.)
Several readings are to be made and the mean thereof taken, but any one
individual reading must not be selected.
II. SUGAR ANALYSIS
1. Sucrose.—To make a polarization, the whole normal weight for 100 cc is to
be used, or a multiple thereof for any corresponding volume.
As clarifying and decolorizing reagents there may be used: Subacetate of lead,
prepared according to the German Pharmacopoeia (three parts by weight of
acetate of lead, One part by weight of oxide of lead, ten parts by weight of water),
Scheibler's alumina cream, concentrated solution of alum. Bone black and
decolorizing powders are to be absolutely excluded.
After bringing the solution exactly to the mark and after wiping out the neck
of the flask with filter paper, all of the well-shaken, clarified sugar solution is
poured upon a dry, rapidly filtering filter. The first portions of the filtrate are
to be thrown away and the balance, which must be perfectly clear, is to be used
for polarization.
2. Water. —In normal beet sugars the water determination is to be made at
105° to 110° C. -
For abnormal beet sugars, there is no commercial method for the determination
of water.
3. Ash.--To determine the ash content in raw sugars the determination is to
be made according to Scheibler's method, employing pure concentrated sulphuric
acid. For an ash determination at least 3 gr. of the sample are to be used. The
incineration is to be carried out in platinum dishes, by means of platinum or clay
muffles, at the lowest possible temperature (not above 750° C).
From the weight of the sulphated ash thus obtained 10 percent is to be de-
ducted and the ash content, thus corrected, is to be recorded in the certificate.
4. Alkalinity.—As, according to the most recent investigations, the alkalinity
of raw sugars is not always a criterion of their durability, the commission abstains
from proposing definite directions for the execution of the investigations.
5. Invert sugar.—The quantitative determination of invert sugar in raw sugars
is to be made according to the method of Dr. A. Herzfeld. (Zeitschrift des
Vereins für die Rübenzucker-Industrie des Deutschen Reiches, 1886, pp. 6 and 7.)
Furthermore the following resolutions were adopted.:
47 Or during the period of transition, 26.048 g in 100 Mohr’s cubic centimeters.
770 Circular of the National Bureau of Standards
The commission declares that only well-closed glass vessels will insure the
stability of samples.
To obtain correct results it is desirable that the samples contain at least 200 gr.
of material.
All of the above resolutions were adopted unanimously by those present.
FOURTH SESSION [4] BERLIN, GERMANY, JUNE 4, 1903
1. Professor Herzfeld outlined the previous work of the commission.—The sets of
quartz plates which had been selected by the Physikalisch-Technische Reich-
sanstalt in Berlin, and which had been tested in the laboratory of the Verein der
Deutschen Zuckerindustrie as to their sugar value, have been distributed to
proper central stations of the countries interested, and there kept at the disposal
of chemists. These plates have been tested in almost all of the countries which
have received the sets, and have been found correct. Some of these stations
have thus far not made a report as to the result of this reexamination, and such
a report is therefore requested.
Execution of the Paris agreement, according to which chemically pure sugar
is to be used for the adjustment of polariscopes and for the testing of plates, has
in some countries met with difficulties because they could not succeed in preparing
chemically pure sugar. The laboratory at Berlin, therefore, offers to furnish
chemically pure sugar. -
In the determination of invert sugar a difficulty has arisen, inasmuch as the
English chemists have of late again declared against the clarification with basic
lead acetate; the commission will therefore have to seek means and methods to
prevent, in this respect, loss of uniformity now secured in the methods of analysis.
The day’s proceedings furthermore covered reports concerning:
* º Practical experiences made with the uniform methods of analysis agreed upon
| Il tº 3, TIS.
II. The valuation of “sand” and “krystallzucker” in international trade.
III. Introduction of international uniform directions for sampling raw sugars.
IV and V. Influence of temperature on the specific rotation of sucrose, and
introduction of temperature-corrections when the temperature of observation
differs from the temperature of 20° C, which has been accepted as the normal
temperature.
VI. Determination of the sugar subject to duty or bounty contained in sac-
charine products and fruit preserves.
VII. Chemical control as an aid to the “entrepôt” system, sanctioned by the
Brussels Convention.
FIFTH SESSION [5] BERN, SwitzERLAND, AUGUST 3 AND 4, 1906
1. The chairman in a review of the achievements of the commission designated the
duties of the commission to be purely analytical.—The commission has for its object
the regulation of the methods of sugar analysis and endeavors to secure the work-
ing of chemists according to uniform and the best methods, but the commission
does not undertake to establish trade customs. The commission does not recog-
nize resolutions carried by majority vote; it is in fact necessary that at least the
representatives of the most important countries interested in sugar be in accord
On a question before the same is presented for acceptance, as otherwise no reliance
can be placed on the recognition of the resolutions by chemists.
2. Determination of a method of preparing Fehling’s solution as well as the manner
of making invert-sugar determinations.—Messrs. Watt and Wiechmann com-
municated the results of their investigations. Mr. Watt preferred the volu-
metric method, Mr. Wiechmann the gravimetric method for commercial analyses.
The latter moved that clarification with basic lead acetate shall be obligatory for
the examination of sirups. This recommendation was indorsed by Messrs. Watt
and Prinsen Geerligs and thereupon also by the entire commission.
The chairman reported on tests made for the comparison of Violette’s and
Fehling’s solution, which had not yet been completed. He announced that
Mr. Munson, the chairman of the Association of American Agricultural Chemists
had, through intervention of Mr. Wiechmann, sent him a resolution of the asso-
ciation named, wherein the same expressed the wish to work hand in hand with
the commission in the matter of securing a uniform alkaline copper solution.
Mr. Pellet also presented a paper on this subject, which was published in the
Sucrerie Indigène, as well as in the Deutsche Vereinszeitschrift.
Polarimetry, Saccharimetry, and the Sugars 771
Mr. Strohmer promised a later report of his experiments bearing on this ques-
tion, which are not yet completed. He recommended retaining for the present
the so-called Herzfeld method.
Mr. Watt declared himself against basic lead-acetate clarification for solid
SugarS.
Mr. Sachs refrained from voting.
Mr. Saillard, as well as Mr. Dupont, expressed himself in favor of retaining
basic lead acetate clarification as long as the present method was used.
Mr. Pellet declared himself against the use of basic lead acetate as a clarifying
reagent.
Mr. Schukow favored this clarification in commercial analysis.
Mr. Watt handed in the following declaration:
“The difference between the amount of the reducing substances in the clarified
and the nonclarified solution of beet sugar lies so closely within the limits of the
errors of observation that a clarification is unnecessary; but in products which
contain a large amount of glucose, a clarification is of great importance.”
Mr. Herzfeld was of the opinion that he could not accept the first half of the
declaration, the difference being, indeed, a small one, but giving rise to consider-
able annoyance in trade.
Mr. von Buchka proposed to defer the question of the composition of Fehling’s
solution and to have the same studied further by a separate commission.
Mr. Geerligs expressed himself in favor of the basic lead-acetate clarification
for sirups.
Mr. Main spoke against the basic lead acetate-clarification in raw sugars.
The chairman proposed to request the chemists of Great Birtain to discuss this
question in a separate conference once more with delegates of the commission in
order to try in this manner to bring about an agreement.
The proposition of the chairman was accepted by the commission and a sub-
commission was appointed, consisting of Messrs. Strohmer, Saillard, Sachs,
Schukow, Van Ekenstein, Watt, Main, Von Buchka, and Herzfeld, this subcom-
mission to take part in the conference with the chemists of Great Britain.
The chairman agreed to ask for the intervention of the German export societies
to the end that the conference might soon be called in London.
The question of Fehling's solution should be subjected to further study.
3. Uniform international directions for sampling sugar products.
4. Resolution concerning a uniform form and manner of expression of certificates
of analysis for the international sugar trade.
Mr. Saillard presented the following resolutions:
1. As long as it is not settled that the degree of alkalinity is a sure criterion for
the keeping qualities of sugars, the determination of alkalinity shall not be con-
sidered in international commerce.
2. The commission shall determine upon a uniform method by which the trade
yield (rendement) for the sugar is to be calculated, in establishing scientific
molasses coefficients for the impurities (ash and invert sugar) the relation of which
is used in the certificates of analysis.
3. The State laboratories shall also take part in the endeavors to bring about
uniformity, in order to cause a disappearance of the differences between trade
ash determinations and Regie ash determinations. (France.)
These resolutions were accepted by the commission, and the commission also
decided, for the present, not to indorse any specific form of certificate of analysis.
5. Avoidance of the precipitate error in optical sugar analysis.
6. Suggestions for the preparation of unchangeable color standards in place of the
raw sugar used for the Dutch Standards.
After a report by the chairman on the substitution of samples of colored glasses
for the Dutch standards and a discussion of the question, the commission unani-
mously expressed the wish that the valuation of sugar according to its color
might soon be abandoned altogether, because this practice was to be condemned
from the scientific as well as from the practical point of view.
7. Concerning a method to be recommended for the determination of the Sugar
content of beets.-The commission was of the opinion and unanimously adopted
the resolution that the aqueous digestion method for the determination of the
sugar content of the beets, if it be executed with due regard to the precautions
suggested by Pellet, Sachs, and others, was to be recommended in preference to
the alcohol method. The commission charged Messrs. Pellet, Sachs, and Herles
with presenting detailed working directions of the method.
8. A uniform international sugar weight-After a review by the chairman of the
prior discussions on this topic, the introduction by Mr. Dupont of a proposition
772 Circular of the National Bureau of Standards
to accept 20.00 gr. as the normal weight, and a thorough debate of the proposition,
the chairman put the question to those present concerning the desirability of
retaining 26.00 gr. as the normal sugar weight for saccharimeters.
Mr. Sachs replied in the affirmative.
Mr. Saillard did not consider it necessary that all countries should have the
same normal weight in order to have a uniform method.
On the question being put by the chairman, the representatives present of
America, Java, Great Britain, Russia, and Austria-Hungary declared themselves
against the normal weight of 20.00 g and for the normal weight of 26.00 g.
Mr. Sachs declared himself in accord with Mr. Saillard to admit 20.00 g, but not
to prescribe it.
9. Conference regarding measures to secure an internationally valid uniform
method of beet-seed valuation.—On the recommendation of the chairman the proposi-
tion was accepted that the commission should not occupy itself with the establish-
ment of standards (Normen), but only with the establishment of methods of
investigation.
Hereupon a subcommission was chosen to work out uniform methods of exami-
nation; Mr. F. Strohmer was appointed chairman of the same.
The following were elected members of the subcommission: Messrs. Strohmer,
president; Saillard, Boussaud (Paris), Sachs, Schukow, Müller (Halle), Krüger
(Bernburg), Herzfeld, Raatz, von Dippe, Heine, Briem, Neumann, and Herles.
The commission was authorized to increase its numbers by the election of further
members. -
SIXTH SESSION [6] LONDON, ENGLAND, MAY 31, 1909
1. Report of the work of the International Commission since its last session.— Mr.
Herzfeld reported that the results of newer investigations speak against the views
expressed by the members of the commission in Bern, making obligatory the
clarification with basic lead acetate for the determination of invert Sugar in sirups.
For this reason this matter was therefore that day given place on the program to
permit of another resolution. All other resolutions taken in Bern have been put
into practice.
Prof. Villavecchia in Rome has agreed, in a letter addressed to the chairman,
that the commission shall be called in consultation in case an internationa
commission of the Government works out directions for sugar analysis.
Agreeable to the resolution taken in Bern, a compilation of the proceedings to
date of the commission has thus far been printed only in German. Copies of this
pamphlet will be sent to the members of the commission by the chairman if they
so desire. A compilation of the resolution adopted thus far by the commission,
which has been prepared by Mr. Wiechmann, of New York, was distributed.
Messrs. François Sachs and Saillard promised to publish such a compilation in
French. -
Mr. Strohmer, Vienna, then reported on the doings of the Subcommission for
Uniform Methods of Beet-Seed Analysis, appointed in Bern, which had met under
his direction in Vienna on May 24, 1907, but which had taken definite resolutions
only with regard to uniform methods for the determination of water and the
determination of impurities. A report concerning the session of the subcommis-
sion has already been published in the technical journals.
At the suggestion of the referee, the International Commission decided that the
introduction of uniform methods of beet-seed examination was to be postponed
until it should be settled whether, and in what manner, the present standards
(Normen) are to be changed.
2. Unification of the tables for the calculation of the contents of sugar solutions from
their density.—Messrs. Saillard, Paris, and Von Buchka, Berlin, reported on this
topic. Their findings will be published in full in the technical journals.
On the motion of Mr. Sachs, seconded by Messrs. Saillard, Prinsen Geerligs,
Strohmer, Neumann, and Pellet, the commission voted unanimously to accept
a single table as standard at the temperature of 20° C, which is to be based
upon the official German table. From this, other tables may be calculated at
other temperatures, for instance, at 15°C, 17.5° C, 30° C, etc., as well as a
table according to the Mohr system, 20° C : 20° C.
3. Propositions for the use of uniform clarifying reagents for the analysis of sugar
products.-Referees: Messrs. Prinsen Geerligs, Java, and François Sachs, Brussels.
Their findings will also be published in the technical journals. In this connection
Mr. Herles recommended basic lead nitrate as a clarifying reagent.
Polarimetry, Saccharimetry, and the Sugars 773
After an extensive debate in which all delegates took part, the commission unani-
mously decided that for the direct polarization of solutions of raw sugar products,
basic lead acetate shall also in future be used for clarification, but not in excess.
For fluid sugars (sirup and molasses) basic lead acetate may not be employed for
the determination of invert sugar, but only neutral lead acetate as a clarifying
reagent.
An agreement could not be reached concerning the clarifying of solutions of
solid raw sugars for the purpose of the determination of invert sugar, as the English
chemists remained firm in their former position to effect no clarification whatever
for the determination of invert sugar.
4. Agreement as to a uniform momenclature for the products of sugar manufacture,
especially in view of the food laws.—Referee: Mr. Strohmer, Vienna, made a report
on this topic which will be published in the technical journals. On the motion
of the referee and of Messrs Saillard and Silz, a resolution in this matter was, for
the present, postponed.
5. Dr. Wiley, of Washington, read two articles by Messrs. A. Hugh Bryan and
C. A. Browne, New York, concerning the conditions of basic lead acetate clarifica-
tion and on temperature corrections in raw-sugar polarizations, which are to be
published at once. In consequence of the declaration of Dr. Wiley that in order
to avoid temperature corrections the American Government laboratories for
sugar analysis are soon to be provided with cooling arrangements in order that
the polarizations shall be made exclusively at the normal temperature of 20° C,
the commission avoided voting on the resolution of Mr. Browne, New York, in
which the avoidance of any and every temperature correction in raw-sugar
analysis is demanded. (See article by Mr. Browne in the technical journals.)
Prior to this, this resolution has been fully established by Mr. Horne, representing
Mr. Browne.
An article by Mr. Horne, on the use of dry basic lead acetate clarification in
sugar analysis, could not be read in this session of the commission. This article
has been published in the Zeitschrift des Vereins der Deutschen Zucker-Industrie
SEVENTH SESSION [7] NEW YORK, SEPTEMBER 10, 1912
1. Report on the work done since the last session.—Mr. Saillard reported that he and
Mr. Sachs have conferred about the publication of a compilation of the proceedings
of all sessions of the commission in French, and expressed the belief that this will
be achieved in time for the next session.
The German Imperial Bureau of Standards (Normaleichungsamt) promised to
prepare tables for the determination of the percentage composition of sugar solu-
tions from their specific gravity at different temperatures, as was requested at the
London conference.
The following resolution was unanimously adopted:
“Owing to the declaration of Dr. Wiley at the Sixth Session of the International
Commission for Uniform Methods of Sugar Analysis, in London, 1909, that, in
order to avoid temperature corrections the American Government laboratories
for sugar analysis are soon to be provided with cooling arrangements in order that
polarizations shall be made exclusively at the normal temperature of 20°C, and
to the fact that this declaration has not yet been carried into effect, this commis-
sion again expresses the opinion that official polarizations of raw sugar products
shall be made only at the constant standard temperature, 20°C, the presence of
invert sugar and other impurities precluding the use of formulas and tables,
which have been elaborated for correcting the polarization of pure sucrose for
changes of temperature.”
2. Uniform methods of sucrose determination in the raw materials of sugar manu-
facture.—Mr. Saillard, at the behest of the syndicate of sugar manufacturers, of
France, explained that the trade in beets and the trade with molasses does not,
for France, bear the same international character as the trade in sugar and
requested that the international commission treat analytical methods for beets
and molasses only from the viewpoint of analytical chemistry.
Upon the recommendation of Mr. Herzfeld, after a short debate, the commission
refrained from Officially endorsing uniform methods of sucrose determination in
beets and in sugar cane. It was agreed, by publication in the technical journals
of the various countries, to bring the reports of Messrs. Strohmer, Sachs, Saillard,
Wiechmann, Prinsen Geerligs, and Herles, which were read before the meeting, to
the notice of those interested, and to call attention to the propositions of the
referees.
3. Uniform methods for the determination of the specific gravity of sugar solu-
tions.—Mr. Saillard and Mr. von Buchka presented reports on this topic. These
774 Circular of the National Bureau of Standards
reports are to be published. Messrs. Weinstein, Strohmer, and Saillard partic-
ipated in the debate which followed.
It was agreed to publish the reports of the referees, and the following resolutions
were adopted. On motion of Mr. Strohmer, that—
“The International Commission for Uniform Methods of Sugar Analysis
expresses the wish that the various countries may prescribe a uniform temperature
for the density determinations of sugar solutions.
...In trade analyses the use of temperature-correction tables should be dispensed
y w a 4.2 a. a. º.º. tº x i. º.º.i. tº k-x I-, -, 3.5 x ~ + v -
On motion of Mr. von Buchka, that—
“The normal temperature of +20° C is to be retained for trade analyses.
“In density determinations of aqueous sugar solutions the density obtained at
normal temperature shall be referred to the density of water at +4° C and to
V8, Cll O.
“In density determinations made by weighing, the results must be calculated to
2
º °C and to vacuo. To effect this, it will be desirable to use tables prepared for
the purpose.”
Mr. Saillard agreed to the latter part of the resolution, provided that in France
!-
the normal temperature there customary—namely, º °C–be retained in place of
*c.
4. Resolution concerning a further examination of the inversion constants of the
double polarization (Clerget-Herzfeld) method.— Mr. Herzfeld reported that although
the correctness of the constant, 132.66 at 20°C, for a solution which contains the
German half-normal weight of pure sucrose, has been confirmed by numerous
chemists and, finally, by an international commission of chemists, who worked
in Berlin in 1910, yet, on the basis of more recent investigations, it seems to him
desirable to retest the accuracy of this constant in as far as its application in the
analysis of beet molasses is concerned. A committee, consisting of Messrs.
Bates, Bryan, Browne, Prinsen Geerligs, Saillard, Sachs, and Strohmer, is ap-
pointed to retest this constant.
The following reports were also made and the following resolutions adopted:
Mr. A. Hugh Bryan made a report on the necessity of using light-ray filters for
º high-grade sugars, and, On his motion, the following resolution was
adopted:
“Wherever white light is used in polarimetric determinations, the same must be
filtered through a solution of potassium dichromate of such a concentration that
the percentage content of the solution multiplied by the length of the column of
the solution in centimeters is equal to nine.”
Furthermore, Mr. Bates reported on investigations [8] conducted by the
Bureau of Standards which led to the conclusion that the 100 point of sacchari-
meters provided with Wentzke scales at present accepted is not quite correct.
On his motion the following resolution was adopted:
“Inasmuch as recent investigations tend to question the validity of the present
100° point of saccharimeters, and inasmuch as it is desirable that the commission
recognize and fix a transformation factor from absolute degrees to Ventzke
degrees, the chairman is hereby empowered to appoint a committee of three to
fully investigate this question and report at the next official meeting.”
At the suggestion of the chairman, Messrs. Bates, Schönrock, and Strohmer
were elected as members of this subcommittee.
EIGHTH SESSION, [9] AMSTERDAM, 1932
FREDERICK BATEs, president; Louis EYNoN, secretary
Owing to world events, the Commission did not function during the years 1912
to 1932. During this time, many of the delegates in attendance at the seventh
session, including the president, Alexander Herzfeld, and the secretary, F. G.
Wiechmann, passed away. However, the Commission was reconvened in the
Great Senate Room of the University of Amsterdam on September 5, 1932.
Much preparatory work, undertaken chiefly on the initiative of Frederick Bates,
of the National Bureau of Standards of the United States, had been necessary to
insure its success. The first order of business was the adoption of a constitution
and by-laws and the Commission, for the first time in its history, had a definite
rule of procedure. The following were elected officers of the Commission: presi-
Polarimetry, Saccharimetry, and the Sugars 775
dent, Frederick Bates; vice presidents, E. Saillard, O. Spengler, V. Stanek, M. G.
Wagenaar Hummelinck; treasurer, F. Tödt; and secretary, L. Eynon. The
Session, lasting 4 days, was conducted in English, French, and German.
The following subjects comprised the agenda of the session.
SUBJECT 1.-The 100° S point of the saccharimeter
Referee, FREDERICK BATES
Among the recommendations adopted were the following:
“(a) That the Commission adopt a standard scale for the saccharimeter and
that this scale be known as the “International Sugar Scale.” Rotations expressed
in this scale shall be designated as degrees sugar (° S).”
“(b) That the polarization of the normal solution (26.000 g of pure sucrose
dissolved in 100 ml of solution) and polarized at 20° C in a 200-mm tube, using
white light and the dichromate filter, as defined by the Commission, be accepted
as the basis of calibration of the 100° (S) point on the International Sugar Scale.”
2: *:
iſ: 2% sº :: 1ſt
“(h) That the question of the French Scale be held in abeyance.”
SUBJECT 2.—Values of Clerget divisors for the more widely used inversion methods
Referee, F. W. ZERBAN
The referee recommended that study be made of (1) the Clerget methods used
in the various countries, (2) the effect of ash on the Clerget divisor, and (3) the
temperature coefficients of the inversion constants.
SUBJECT 3.-Conductometric determination of the ash content of raw sugars
Referee, O. SPENGLER
The report of the referee reviewed the subject of conductivity ash and recom-
mended further study, particularly with respect to low-grade products, details of
the methods being left to the various countries.
SUBJECT 4.—Errors due to the volume of lead precipitate in testing raw sugars for
polarization
Referee, H. MAIN
The referee recommended that further studies be made using sugar from all
countries. In the meanwhile, the use of Horne's dry lead was permitted.
SUBJECT 5.—Estimation of reducing sugars and the influence of overheating on the
estimation of invert sugar
Referee, L. EYNON
The recommendation of the referee that ten widely used methods be subjected
to study was agreed to. It was further agreed to study methods of estimating
the cuprous oxide.
SUBJECT 6-Refining and keeping qualities of raw came and beet sugar
Referee, H. C. PRINSEN GEERLIGs
It was recommended that no resolution be adopted.
SUBJECT 7.—Standardization of quartz control plates
Referee, O. SCHöNRock
The referee presented resolutions containing detailed specifications for sacchar-
imeter quartz control plates, including tests for optical purity, plane parallelism,
axis error, mounting, rotation, etc.
The Commission agreed to the resolutions presented.
776 Circular of the National Bureau of Standards
SUBJECT 8.—Refractometric estimation of water in sugars and sugar products
Referee, H. MAIN
No definite recommendations were made, the subject being referred to the 1:ext
session of the commission.
SUBJECT 9.—Colorimetry in the sugar industry
Referee, V. SAZA V S K Y
It was recommended that the subject be investigated before the next session
and that such investigations should include sulfitation products.
SUBJECT 10.-The testing of molasses
Referee, E. SAILLARD
The referee recommended detailed study of the various methods.
SUBJECT 11.-Estimation of raffinose
Referee, J. WONDRAK
The following resolution was agreed to: It is recommended that the method of
Paine and Balch should be studied, the influence of salts being taken into con–
sideration, the method of inversion with acids not being sufficiently accurate.
Creydt’s mucic-acid method is also recommended for study.
SUBJECT 12.-Marc volume correction in the digestion process for the estimation of
sugar in beet roots
Referee, V. STANEK
The referee showed that since the volume of the marc varies according to the
country, or even district, in which the beet is grown it would be impossible to
make any estimate of general applicability.
SUBJECT 13.-Estimation of sulfur dioacide in consumption sugar
Referee, J. VONDRAK
The referee recommended the direct titration with iodine for factory control
of sulfur dioxide in sugar products. For exact estimation he proposed that the
sulfur dioxide be distilled from the acidified solution after expulsion of the air
with carbon dioxide; the distillate collected in hydrogen peroxide, bromine water,
iodine solution, or in sodium bicarbonate solution with subsequent oxidation, the
sulfuric acid formed being estimated gravimetrically.
Amendment of Resolution passed at the Third Session of the Commission
(Paris, 1900).
The meeting agreed to a resolution, proposed by F. W. Zerban, to amend the
“Directions for Sugar Analysis,” subhead 1, adopted at the Third Session of the
Commission held in Paris in 1900, to read as follows:
“Single polarization.—To make a polarization, the whole normal weight for
100 ml shall be used or a multiple or fraction thereof for any corresponding
volume. As clarifying and decolorizing reagents there may be used lead sub-
acetate solution or Horne's dry subacetate of lead and salt-free alumina cream.
Bone black and decolorizing powders are excluded.
After bringing the solution exactly to the mark and after wiping out the neck
of the flask with filter paper, all of the well-shaken clarified sugar solution is
poured upon an air-dry, rapidly filtering filter. During the filtration, the funnel
shall be covered with a watch glass Or plate to prevent evaporation. At least
the first 25 ml of the filtrate is to be thrown away and the remainder, which
must be perfectly clear, is to be used for polarization.”
NINTH SESSION [10] LONDON, 1936
FREDERICK BATEs, president; LOUIS EYNON, secretary
The ninth session, held in London, August 31 to September 3, 1936, was marked
by a record attendance of delegates from 20 different countries. The complete
Polarimetry, Saccharimetry, and the Sugars 777
proceedings of the session have been published as a supplement of the International
Sugar Journal and reprinted in several of the sugar journals of other countries,
making it available in various languages.
Space permits only a résumé of the subjects covered at the meeting.
SUBJECT 1.-Constitution and bylaws
Referee, FREDERICK BATES
The president presented a report on proposed amendments, and it was agreed
to adopt the “Constitution and Bylaws.”
SUBJECT 2.-Weighing, taring, sampling, and classification of sugars
Referee, J. Von DRAK
The report of the referee covered the details of the methods employed in the
various countries.
SUBJECT 3.-Conductometric determination of the ash content of raw sugars
Referee, O. SPENGLER
The report pointed out the advantages of the conductometric method due to
the rapidity of execution and simplicity as well as the fact that it gives only the
percentage of soluble ash. The suggestion was made that the differences between
the gravimetric and conductometric ash be submitted to further study.
SUBJECT 4.—Determination of reducing sugars and the influence of overheating on the
determination of invert sugar
Referee, J. H. LANE
The methods employed in the various countries were discussed in detail in the
report. It was recommended that comparative determinations be made by the
Munson and Walker method, Lane-Eynon, and Schoorl methods, and by the
Brown, Morris, and Miller method, with particular regard to the concordance
obtainable by different chemists using the same method.
The subject of defecation of cane molasses for invert-sugar determinations was
recommended for review.
SUBJECT 5.—Determination of the decolorizing and filtering quality of chars
Referee, K. SMOLENskI
The referee reviewed the subject of standardization of tests for the decolorizing
power of carbons. It was suggested that a special committee devise standardized
methods for the evaluation of activated carbons used in the sugar industry.
SUBJECT 6.-Testing of molasses
Referee, E. SAILLARD
The referee reported on a number of methods employed in the analysis of
molasses with particular reference to the determination of sucrose in beet molasses.
In view of the need of standard methods for various types of molasses, the methods
of the National Bureau of Standards were proposed and adopted as tentative.
SUBJECT 7.—Application of refractometer methods to sugar analysis
Referee, E. LANDT
On the recommendation of the referee, a standard scale of refractive indices of
sucrose solutions at 20° C was adopted, together with a table of temperature cor-
rections. They were designated “International Scale (1936) of Refractive
Indices of Sucrose Solutions at 20° C,” and the “International Temperature Cor-
rection Table (1936).” A corresponding scale for use with the tropical model
ºneer at 28° C and a temperature correction table at 28° C were also
adopted.
778 Circular of the National Bureau of Standards
SUBJECT 8.—The 100° S point of the saccharimeter
Referee, FREDERICK BATES
In the report presented by the referee and written jointly by him and Francis
P. Phelps, it was shown that two different saccharimeter scales are in general use.
They are the French Scale and the International Sugar Scale, adopted by the
Commission at the eighth session at Amsterdam. The former is used largely in
France and the French colonies. It was shown that by taking the original data
of the French investigators and recalculating the normal weight for the French
Scale the correct value was 16.269 g instead of 16.29 g. The new value, 16.269 g,
is in exact agreement with the value of the International Sugar Scale.
SUBJECT 9.—Standardization of quartz control plates
Referee, E. EINSPORN
The referee expressed his thanks to Prof. Dr. Schönrock, his predecessor, who
had reported on the conditions of testing quartz plates at the eighth session. The
referee limited his report to a detailed discussion of the following questions:
(1) Optical purity.
(2) Identification marks.
(3) Plate mounting.
(4) Rotation measurements.
(5) International exchange of quartz control plates.
SUBJECT 10.-Test for the evaluation of the refining qualities of raw came and beet
Sugar
Referee, O. SPENGLER
The report pointed out that in judging the refining qualities, a distinction must
be made between cane and beet raw sugars. Methods applicable to both were
discussed and recommended for use.
SUBJECT 11.-Elimination of errors due to lead clarification in polarizing raw sugars
Referee, K. SANDERA
The report of the referee cited various investigations regarding the difference in
polarization after wet and dry lead clarification. After a long discussion, the fol-
lowing recommendation was considered and adopted:
“If no change in the sugar scale is or has been made, clarification shall be effected
with standard lead subacetate solution (3d Session Int. Comm. Paris, 1900);
but if a change from the Herzfeld-Schönrock scale to the International Sugar
Scale is made, then clarification shall be effected with standard dry lead sub-
acetate (Horne's dry lead).”
SUBJECT 12.-The determination of raffinose
Referee, J. WONDRAK
In comparing the rapid optical method of Osborn and Zisch with the enzyme
method of Paine and Balch, the referee considered that the close agreement
obtained on products from American beet—sugar factories could be explained only
by the compensation of the rotation of particular nonsugars, since these substances
are far from being optically inactive, even in acid solution. It was further stated
that the method of Osborn and Zisch or any new method for the determination
of raffinose must be judged by its capacity to give results always in close agree-
ment with those obtained by the basic methods, working with enzymes.
SUBJECT 13.-Colorimetry in the sugar industry
Referee, V. SAzAvsky
In the referee's report which was adopted, it was recommended that absolute
measurement be introduced as far as possible into factory and commercial control.
It was suggested that the program of the section be extended to include the
measurement of turbidity and reflection.
Polarimetry, Saccharimetry, and the Sugars 779
SUBJECT 14.—Values of Clerget divisors for the more widely used inversion methods
Referee, F. W. ZERBAN
The work of a number of investigators was covered in the report of the referee.
The lack of sufficient analytical data caused the referee to recommend the
following:
“It is recommended that the resolution adopted at the eighth session be re-
peated, and that a further study be made of the three subjects mentioned therein.”
This recommendation was agreed to by the Commission.
SUBJECT 15.-Determination of water in sugars and sugar products by drying
'methods
Referee, H. C. S. DE WHALLEY
The report of the referee covered a number of the methods in use in the various
countries. Included in the methods recommended and adopted were the
following:
“(1) That the standard method for moisture in refined sugars and normal raws
should be carried out in a vacuum oven at 60°C, pressure not exceeding 5 cm,
oven bled with current of dry air, drying to constant weight, and dishes to be
metal with close-fitting lids with knobs.
“(2) That the standard method for estimation of water in beet molasses, low-ash
cane sirups, and golden sirups, should be carried out in vacuum ovens bled with
dry air at 70° C, or preferably 60°C, with a pressure not exceeding 5 cm; metal
dishes with close-fitting lids with knob should be used and that with 1 g of solids
approximately 25 to 30 g of 40 to 60 mesh white quartz sand should be used;
water being added to facilitate admixture with the sand and then drying until 2
hourly weighings do not differ by 0.5 mg.”
SUBJECT 16.-Determination of the hydrogen-ion concentration of sugar-factory
products
Referee, K. SMOLENSKI
It was agreed to defer this subject until the next session of the Commission.
SUBJECT 17.--Analysis and evaluation of refined sugars
Referee, K. SANDERA
The report of the referee showed the lack of uniformity in the tests made in the
various countries in the evaluation of refined sugar, and gave a detailed discussion
of some of the methods. He suggested that a selection be made of the tests most
widely used in the evaluation of refined sugars, that these tests be investigated,
and that recommendations be drawn up for carrying them out in a uniform manner.
1. REFERENCES
[1] F. C. Wiechmann, Sugar Analysis, p. 217 (John Wiley & Sons, Inc., New
York, N. Y., 1914); Z. Wer. deut. Zucker-Ind. 47, pt. 1, 235 (1897).
[2] Z. Wer. deut. Zucker-Ind. 48, pt. 1, 389 (1898).
[3] Z. Wer. deut. Zucker-Ind. 50, pt. 1, 357 (1900).
[4] Z. Wer. deut. Zucker-Ind. 53, pt. 2, 889 (1903).
[5] 4. Yº gººd 56, pt. 2, 317 (1906); 57, pt. 1, 6 (1907); Int. Sugar
. 9, 5 (1 te
[6] Z. Wer. deut. Zucker-Ind. 59, pt. 1, 434 (1909); Int. Sugar J. 11, 428 (1909).
[7] Z. Wer. deut. Zucker-Ind. 63, pt. 1, 25 (1913); Int. Sugar J. 15, 7, (1913);
Am. Sugar Ind. p. 62 (Nov. 1912).
[8] F. J. Bates and R. F. Jackson, Bul. BS 13, 68 (1916) S268.
[9] Int. Sugar J. 35, 17, 62 (1933).
[10] Int. Sugar J. 39 (Jan. Suppl. 1937).
XXXVIII APPENDIX 3.−UNITED STATES CUSTOMS
REGULATIONS
1. REGULATIONS GOVERNING THE WEIGHING, TARING, SAMPLING,
CLASSIFICATION, AND POLARIZATION OF IMPORTED SUGARS
AND MOLASSES
[Reprinted from the Customs Regulations of 1937]
The following regulations promulgated by the United States Treasury De-
partment are reproduced here because of their general interest. They were pre-
pared with the cooperation of the National Bureau of Standards.
GENERAL INSTRUCTIONS
Art. 693. Duties of customs officers (T. D. 46513).--(a) Duties of entry clerks.—
Estimated duties shall be taken on the entry of Cuban raw sugar on the basis of
not less than 96° polariscopic test unless the invoice shows the sugar is of a lower
grade than that of the ordinary commercial shipment.
(b) All customs officers and employees having duties to perform in connection
with the treatment of imported sugars, sirups, and molasses are hereby instructed
to use the utmost care and vigilance to insure that the work of weighing, gauging,
sampling, classifying, and testing is accurately and efficiently performed. -
(c) Each inspector, weighing officer, gauging officer, and sampler shall be
furnished with a copy of the regulations relative to sugars, sirups, and molasses.
The appraiser shall notify the collector of the boundaries of sugar districts and
the location of the examiner's or sampler’s office in each district, and such in-
formation shall be furnished by the collector to the inspectors and weighing
officers. The examiners and samplers in charge shall be held responsible by the
appraiser for the strict and impartial enforcement of these regulations, and to
this end they shall be notified relative to the time of discharge and weighing of
sugar and molasses cargoes in their respective districts by the inspector or weigher
in charge of the same.
(d) Duties of inspector.—Inspectors are directed to exercise a personal super-
vision over the discharging of sugar cargoes. They shall have their permits
endorsed by the examiner or sampler in charge after the samples have been
obtained in accordance with these regulations. Dock sweepings shall be gathered
up and weighed and sampled when discharging has stopped for any cause. The
inspector is directed to keep, in every instance, an accurate account of the kind
and number of packages of sweepings, which he shall endorse on the back of the
permit or lighter manifest before it is presented to the appraiser’s office for
endorsement. If no sweepings are found, the inspector shall endorse the permit
or manifest accordingly.
(e) Duties of weighing officers.—The weighers shall do the actual weighing and
recording of the results, and shall not permit any other person to handle the
scales. They shall be required to exercise a strict scrutiny of the conditions under
which the weighing is being done, shall keep the scales clean of all foreign accre-
tion, to the end that atmospheric and other exterior influence inimical to accuracy
may be avoided, and to obviate the possibility of any drafts passing over the
scales unweighed or being reweighed. Scales with beam indicating 1 pound are
to be employed in weighing sugar wherever possible.
Art. 694. Separation of shipments.--When an importation is consigned to two
or more consignees, each consignee's merchandise shall be treated as a separate
importation, provided separate entry is made therefor.
Art. 695. Time of weighing and sampling.—All sugars and sugar products re-
quiring either weighing or sampling shall have those operations performed at the
time of unlading. Merchandise requiring both weighing and sampling shall have
those operations performed simultaneously whether discharged under either a
regular or a special permit. 781
323414°—42—51
782 Circular of the National Bureau of Standards
Art. 696. Absorption of sea water.—Inasmuch as the absorption of sea water
or moisture reduces the polariscopic test of sugar, there shall be no allowance on
account of increased weight of sugar importations due to unusual absorption of
sea water or of moisture while on the voyage of importation. That portion of the
cargo claimed by the importer to have absorbed sea water or moisture on the
voyage of importation shall be weighed, sampled, classified, and tested separately.
This claim must be made at the time of weighing. Special care must be taken
that such sugars are sampled so as to represent the contents of the packages.
Art. 697. Molasses not for eactraction of sugar or for human consumption. (T. D.
48127.)–(a) Tariff Act of 1930, paragraph. 502:
* * * Molasses not imported to be commercially used for the extraction of
sugar or for human consumption, three one-hundredths of 1 cent per pound of
total sugars.
(b) Such molasses may be released upon the deposit of estimated duties at the
rate specified above upon compliance with the following conditions:
(1) There shall be filed in connection with the entry an affidavit of the im-
porter that the molasses is not to be used commercially for the extraction of
sugar or for human consumption. For the purpose of these regulations, the
phrase “molasses not imported to be commercially used for the extraction of
sugar or for human consumption” shall be construed to include, in addition to
molasses used in animal feed and other products not for human consumption,
molasses which after importation is utilized in the production of articles such as
yeast, vinegar, alcohol, rum, gin, or whisky, in such manner that fermentation
or other chemical change alters its character and chemical composition so that
molasses or sugar does not appear in the final product, and to exclude molasses
used for the extraction of sugar, or used either in its condition as imported or
after undergoing purifying or blending processes, or both, for table purposes Or
as a sweetening, coloring, or flavoring agent in the production of article's for
human consumption.
(2) If the molasses is entered for consumption there shall also be filed in con-
nection with the entry a bond on customs form 7551 or 7553, with an added con-
dition for the payment of the increased duty in the event the molasses is used
contrary to the statements made in the above-mentioned affidavit. Liquidation
of the entry shall be suspended pending proof of use or other disposition of the
merchandise.
(3) If the molasses is entered for warehouse the regular warehouse entry bond.
customs form 7555, shall be given and withdrawals shall be made on customs
form 7506. Estimated duty at the rate specified above shall be deposited at the
time of withdrawal and the liquidation of the warehouse entry shall be suspended
pending proof of use or other disposition of the merchandise.
(4) Within 3 years from the date of entry (in the case of warehouse entries as
well as consumption entries) the importer shall submit an affidavit of the super-
intendent or manager of the manufacturing plant stating the use to which the
molasses has been put. If the collector is satisfied that the molasses has not been
used in a manufacturing plant but was sold as molasses to the ultimate user, he
may accept as proof of the nature of such use an affidavit of the wholesaler or other
person making the final sale of the product. Such affidavit shall state the quan-
tity sold and the purpose for which the seller understood the purchase to be made.
All affidavits as to use provided for in this subparagraph should state affirmatively
the particular use, but may be accepted as sufficient if they specify alternative
uses, provided each of the uses so specified is a use other than for human con-
sumption or for the extraction of sugar as defined in subparagraph (1). If the
molasses has not been used in the United States, evidence of exportation or de-
struction satisfactory to the collector should be required. Affidavits as to use and
affidavits or other documents showing exportation or destruction should, if
practicable, be filed in duplicate, one copy to be forwarded to the comptroller
of customs. -
(5) Upon satisfactory proof of use of the molasses for purposes other than for
the extraction of sugar or for human consumption or of the exportation or de-
struction thereof the entry may be liquidated at the rate of three one-hundredths
of 1 cent per pound of total sugars. When such proof of use or other disposition
of the molasses is not made within 3 years from the date of the entry, or the use
shown does not warrant the classification claimed, the entry shall be liquidated
at the higher rate applicable under the first clause of paragraph. 502.
(6) Entries covering blackstrap molasses, as hereinafter defined, may be ac-
cepted and liquidated with duty at the rate of three one-hundredths of 1 cent per
pound of total sugars after the filing of the affidavit prescribed in subparagraph
(1) without compliance with the special requirements of subparagraphs (2), (3),
Polarimetry, Saccharimetry, and the Sugars 783
(4), or (5). For the purposes of these regulations, blackstrap molasses is defined
as “final” molasses practically free from sugar crystals, containing not over 58
percent of total sugars and having a ratio of— r”
total sugars)> 100
Brix
not in excess of 71. In the event of doubt, an ash determination may be made;
an ash content of not less than 7 percent indicates a blackstrap molasses within
the meaning of these regulations.
(7) The rates of duty above specified are subject to a rebate of 20 percent
provided for articles the growth, produce, or manufacture of Cuba, upon com-
pliance with the provisions of article 846.
Art. 698. Filing of affidavit for molasses in tank cars.--When an importation of
molasses is shipped in tank cars the importer shall file with the collector an affi-
davit showing whether there is any essential difference either in total sugars or
character of the molasses in the different cars. A composite sample shall be made
by the examiner to represent the importation. When, in the opinion of the
appraiser, the molasses in any of the cars is not identical with that in the other
cars, such cars shall be gauged, sampled, classified, and tested separetely.
Art. 699. Expense of unlading.—No expense incidental to the unlading, trans-
porting, sorting, or arranging of sugars and molasses for the convenient weighing,
gauging, measuring, sampling, or marking thereof shall be borne by the Govern-
ment. When weighing, gauging, sampling, or measuring is performed concur-
rently with the unlading, or while the merchandise is being transported from the
vessel's side to the importer’s premises, no part of the expense of the transportation
or handling of the merchandise shall be borne by the Government.
Art. 700. Standardization of weights and measures.—In the carrying out of
these regulations, all weights and measures shall fully comply with the standards
established for such weights and measures by the National Bureau of Standards.
Art. 701. Mixing classes of sugar.—No regulations relative to the weighing,
taring, sampling, classifying, and testing of imported sugars shall be so construed
as to permit of mixing together sugars of different classes, such as centrifugal,
beet, molasses, or any sugar different in character from those mentioned, for the
purpose of weighing, taring, sampling, classifying, or testing.
WEIGHING OF SUGAR
Art. 702. Method of weighing.—All imported raw sugars shall be weighed
without regard to mark. Raw sugars are to be weighed gross and, whenever
practicable, in drafts of uniform size or of a uniform number of bags, and the tare
of trucks and slings, if weighed, deducted periodically as hereinafter prescribed.
Art. 703. Recording weights—Reports.— (a) The weigher’s return shall show
the total weight of the cargo, and shall also show separately for each scale, each
half day, the weight of all (1) wet sugar, (2) damaged sugar not wet, (3) ship
sweepings, (4) dock sweepings, (5) other sugar. The weigher shall make a daily
report on customs Form 5993 to the examiner or sampler in charge, which shall
show separately for each scale, each half day, the total number of packages weighed
of (1) wet sugar, (2) damaged sugar not wet, (3) ship sweepings, (4) dock sweep-
ings, (5) other sugar. All ship and dock sweepings and sugar samples taken before
weighing shall be weighed before the weigher completes his half day’s work. In
no instance shall the weigher make a return by filling in the weight from the invoice.
(b) For the purpose of recording and computing net weights, each working day
will be divided into four periods, and the weights for each period kept separate,
and recapitulated or summarized by starting a new page for each period. All
weights are to be recorded in a dock book (or on adding-machine sheets if the latter
are used) in the usual manner, the truck number, number of bags in each load,
and gross weight being entered in one line. Actual tare of the trucks and slings,
if weighed, shall be taken before commencing work in each period by weighing all
trucks and all slings for each scale morning and noon and one-half the trucks and
slings for each scale for the intermediate periods. The truck numbers, individual
and average weight per truck, and total and average weight per sling are to be
placed in the middle bottom column, right-hand side of dock book, or in desig-
nated place on adding-machine sheets. The total tare, computed according to the
number of drafts weighed, shall be deducted from the summary of the gross weight
for each period. In computing such tare for each period's work, if a fraction of
one-half pound or less results it shall be discarded; if over one-half pound, the
next higher unit shall be taken. In addition to the recapitulation, each page must
784 Circular of the National Bureau of Standards
have denoted thereon the designating scale letter or number, date, and signature
of weigher.
Art. 704. Testing weighing implements.-Weighers will be required to test and
balance their scales or weighmaster's beams with United States standard test
weights immediately before the beginning of work and every hour, on the hour,
thereafter, and to record the result of balance. They will furthernhore be required
to see that all trucks and slings used in connection with weighing are maintained
at an established uniform weight.
Art. 705. Automatic scales.—Wherever available, the Treasury Department
automatic scales shall be used in preference to all other types of scales. They
shall be under the direct supervision of the mechanical and electrical engineer in
charge of scales and that official shall be held responsible for their proper operation
and repair. The weigher shall operate the scales in strict accordance with instruc-
tions furnished by said official. A copy of these instructions shall be kept per-
manently in each scale house. All defects in operation shall be promptly reported
to said official and a notation in reference to the same made in the dock book or on
the adding-machine sheet.
Art. 706. Custody of scale keys.--The inspector or officer in charge of the station
shall have charge of the keys necessary for the operation of the automatic scales.
In commencing the weighing of a cargo it shall be his duty to unlock the scale
houses and assign to each weigher or officer acting in that capacity the adjusting
and operating keys corresponding to the designating letter of the respective scale,
and to the weigher or inspector in charge one scale house key. The station inspec-
tor, or where none is assigned, the weighing officer in charge, shall retain in his
custody the keys for the record compartment, and under no circumstances permit
them to pass into the possession of any other person without written instructions
from the collector. At the completion of the day’s work it shall be the duty of
the inspector in charge to see that the scale houses are locked and otherwise
secured against intrusion, and that all electric power is properly switched off.
Those to whom keys have been assigned will be held to a strict accountability
for their safekeeping.
Art. 707. Reports on operation of automatic scales.—At the end of each working
day, each weigher (or official acting in that capacity) shall mail to the mechanical
and electrical engineer in charge of scales a time slip (customs Form 6031) stating,
with the designating letter of scale, the number of hours the scale was in use, the
hourly balance weights and adjustments, and the number of bags weighed on the
scale in each period, together with the name of the vessel from which the cargo
was discharged and a note of any defect in operation of the scales.
Art. 708. Removal of tapes.—Upon the completion of weighing of a cargo on an
automatic scale, the designated inspector shall remove the printed tape record
from the scales. He shall record on the same, legibly and permanently, name of
vessel, date of arrival, designating letter of scale, and time of removal of tape;
and will be held accountable for the same until properly filed with the weigher’s
return. Under no condition will the regularly designated inspector permit the
keys for the record compartment of the scales to pass into possession of any
person not designated by the collector to remove record tapes.
TARING OF CONTAINERS
Art. 709. Taring by mark (T. Ds. 32796, 87573).-(a) All tare shall be taken
by mark. When sugar is in tierces, hogsheads, barrels, boxes, or irregular
packages, actual tare shall be taken. When sugar is in bags (other than the
standard Cuban sugar bag), baskets, and mats, the actual tare shall be taken and
determined by cleaning the following percentage of the receptacles in each mark:
Percent
Marks of less than 1,000--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4
Marks of 1,000 and less than 4,000 (but in no such mark less than 40 receptacles) -------------------- 3
Marks of 4,000 and less than 10,000 (but in no such mark less than 120 receptacles) - - - --------------- 2.5
Marks of 10,000 and over (but in no Such mark less than 250 receptacles)-------------------- - - - - - - - - 1-2
(b) When sugar in the containers mentioned above is discharged and weighed
at points other than refineries, actual tare shall be taken of the largest number of
receptacles practicable and the percentage tare per mark shall be as nearly as
possible that given above.
(c) When, in the opinion of the weigher, the condition of the receptacles is such
as to make advisable the taring of a larger percentage than that provided above,
he shall tare as many receptacles as, in his judgment, are necessary to secure a
proper tare. All such receptacles are to be thoroughly cleaned by scraping and
sweeping before the tare is taken.
Polarimetry, Saccharimetry, and the Sugars 785
Art. 710. Schedule tare (T. Ds. 33701, 36305, 36306).--(a) In general, there
shall be allowed a schedule tare of 2% pounds per bag for Cuban sugar imported
in standard bags. A sugar bag having an area of 1,392 square inches when laid
flat (29 inches in width by 48 inches in length) is hereby defined for tare purposes
as the standard Cuban sugar bag. When the area of sugar bags varies by more
than 2 percent from the standard area of 1,392 square inches, or the bag is not
of the usual textile, the schedule tare shall be increased or diminished in propor-
tion to the amount the area or the weight of the bags varies from that of the stand-
ard bag. In determining schedule tare, the percentage of the number of bags
to be measured for each mark shall be the same as that for actual tare. Where
the bags bearing any mark differ in size, the schedule tare allowed shall be based
upon the average dimensions of the entire number of bags bearing such mark.
(b) In measuring the bags they shall be flattened out to their fullest extent and
the folded part at the mouth of the bag shall be turned out. In determining the
length, the measurement shall be taken along the seam at the side. In determin-
ing the width, the measurement shall be taken across the back at a distance of
about 4 inches from the mouth.
Art. 711. Actual tare (T. Ds. 36305, 36306).-In determining actual tare, all
bags shall be selected with careful discrimination as to condition and every care
exercised to insure their accurately representing the mark. The bags shall be
carefully dry-cleaned by sweeping and scraping and then weighed, which weight
shall be taken as the actual tare.
Art. 712. Verification of schedule tare (T. D. 32976).--When the collector has
reason to doubt the correctness of any schedule tare, he shall verify such schedule
tare by taking actual tare. If the importer shall file a written application repre-
Senting that there is an excessive number of damaged bags in a given importation
and shall give the approximate percentage of the damaged and sound bags, and
shall on that account request that actual tare be taken, the collector, if satisfied
that the facts are as stated, shall determine the actual tare on the importation.
Art. 713. Acceptance of actual tare.—Whenever actual tare is determined on
any importation and is found to differ from the schedule tare by not more than
5 percent, the schedule tare shall be allowed on such importation. In the event
that the actual tare differs from the schedule tare by more than 5 percent, the
actual tare shall be the accepted tare.
GAUGING OF MOLASSES
Art. 714. Plans of storage tanks.--Where molasses is imported in bulk in tank
vessels and is to be pumped or discharged into storage tanks, the gallonage capac-
ity of the latter, per inch in height, shall be ascertained while the storage tank is
empty on the basis of 231 cubic inches to the gallon. Before the discharging is
permitted, there must be on file in the customhouse a certified copy of the plans
of the storage tank, showing all inlets and outlets. All outlets of the storage
tank shall be sealed by the gauger before pumping begins. In the event a storage
tank is partially filled with molasses, the gauger will ascertain the quantity con-
tained therein before the pumping of the new importation is commenced. He
shall also carefully examine the pump line to see that the same is in good condition.
Art. 715. Time of gauging (T. D. 42937).-After the discharge is completed, all
inlets to the tank will be carefully sealed and the molasses left undisturbed for
a period not to exceed 20 days, to allow for settling, before being gauged. When
the importer requests in writing immediate gauging, the same shall be allowed by
the collector.
Art. 716. Tank gauging.—The report of the gauging of the molasses shall show
the number of gallons of molasses and the temperature of the molasses in degree
centigrade determined at the time of gauging. Report as to gauge and temperature
is to be made to the examiner (customs Form 5991). The depth of the molasses
contained in the storage tank shall be ascertained by means of a steel rod, having
a movable brass scale expressed in inches and tenths of inches. The measure-
ment shall be taken from the bottom of the tank to the top of the liquid, deduction
being made for the molasses, if any, contained in the tank before the discharge
began. If there is foam present the gauging shall be made with the aid of the
“foam can”, which shall be in accordance with the following specifications: The
foam can shall be made of heavy galvanized-iron pipe 5 feet long by 7% inches in
diameter fitted at the bottom with a wooden plug attached to the can by means
of a chain, and fitted at the top with suitable hooks for attaching ropes for lower-
ing. The method of using shall be to place the wooden plug in the bottom of
the can and lower the can into the molasses by means of the ropes attached to the
top. The gauging rod is passed through the can, releasing the wooden plug at the
786 Circular of the National Bureau of Standards
bottom, allowing the molasses to flow into the can to the level of the molasses in
the tank. The gauging rod is then lowered through the can to the bottom of the
tank and an accurate gauge of the molasses without foam is registered on the gauging
rod. This procedure shall be followed both on immediate gauging as well as gauging
after the lapse of the 20-day period in all cases where foam is present. No allow-
ance shall be made for occluded air or other gases in the body of the molasses.
The depth of the imported molasses having been ascertained in inches, the result
will be multiplied by the number of gallons per inch in height previously ascer-
tained when the storage tank was measured empty.
Art. 717. Gauging tank cars.—When molasses is imported in tank cars the quan-
tity contained therein will be ascertained by gauge.
SAMPLING OF SUGARS, SIRUPS, AND MOLASSES
Art. 718. General sample defined (T. D. 33228).-(a) In sampling imported raw
sugars, a general sample shall be taken, that is, each importation shall be sampled
without regard to marks and 100 percent of the packages shall be sampled. A
separate general sample shall also be taken of (1) wet sugar, (2) damaged sugar
not wet, (3) ship sweepings, (4) dock sweepings. In order to prevent any unnec-
essary labor and inconvenience in obtaining the sample, the inspector shall direct
that the packages when discharged from the vessel upon the wharf shall be so
placed that the sampler can readily obtain a 100-percent sample. All ship and
dock sweepings shall be sampled before the sampler completes his half day's work.
It shall be the duty of all samplers to secure a thoroughly representative sample.
(b) In sampling separate importations of sirups or molasses placed in the same
tank, care must be taken to get truly representative samples of each lot.
Art. 719. Stained bags (T. D. 33228).-In the event that bags are stained from
lying in storage, or from any other cause, but the sugar not damaged, the sampler
in charge, as well as all other samplers, shall exercise every precaution to see that
the bags come alternately with the clean and stained sides up. When, in the
opinion of the sampler in charge, the bags are not being so discharged, he shall
direct the attention of the inspector to that fact, and it shall be the duty of the
inspector to thereupon stop the discharge of the cargo until the instructions of the
sampler are complied with. If, from any cause, in any cargo, the condition of
the bags from the ground tier or any other tier shall differ markedly from the
condition of the cargo as a whole, such bags shall be treated as damaged.
Art. 720. Care of samples—letter of transmittal–Keys.-(a) In the treatment
of sugars under these regulations, great care shall be exercised by samplers and
other appraising officers to prevent the drying out of samples, as well as their
absorbing moisture. A standard sugar bucket shall be used in which to collect
the samples. It shall be made of heavy galvanized iron and have a height of 31%
centimeters and a diameter of 18% centimeters. The covers of the buckets must
be kept closed, except when momentarily opened to receive the sample. All the
buckets containing samples from a given half day for each cargo shall be filled,
with the exception of one. The label on each bucket must identify the sugar and
the particular half day on which its contents were drawn and the name of the
officer responsible for the sampling of same. All buckets, after being so labeled,
shall be locked before leaving the spot where the samples are being drawn. The
examiner or sampler in charge shall forward the samples to the appraiser’s stores
with a dock list on customs Form 6483–B, on which partially filled buckets shall
be noted as one-fourth, one-half, or three-fourths. After the discharge of the
cargo has been completed the examiner or sampler in charge shall forward a letter
of transmittal to the appraiser on customs Form 6461.
(b) The keys of the locks used on sugar buckets shall be in possession of the
assistant appraiser or the examiner at the appraiser’s office, who shall have sole
custody of such keys.
Art. 721. Dimensions of sugar triers.-The sugar triers used shall have the fol-
lowing dimensions:
Short trier Long trier Barrel trier
Centimeters Centimeters Centimeters
Length over all----------------------------------------------- 40. 6 152.4 104. ()
Length to Spoon.---------------------------------------------- 22.9 132. 1 91.4
Length of Shank---------------------------------------------- 17. 8 20.3 12. 7
Length of handle--------------------------------------------- 26. 7 38. 1 30. 5
Width of Spoon.----------------------------------------------- 2. 7 2. 5 2. 5
Depth of Spoon.----------------------------------------------. ... 8 1. 3 l. 1
Diameter of handle------------------------------------------- 3. 8 3. 8 3. 8
Polarimetry, Saccharimetry, and the Sugars 787
Art. 722. Receptacles—How sampled.—Sugar in hogsheads and other wooden
packages shall be sampled by putting the long trier diagonally through the pack-
age from chime to chime, one trierful to constitute a sample, except in small lots,
when an equal number of trierfuls shall be taken from each package to furnish
the required amount of sugar necessary to make a sufficient sample. In the
sampling of baskets, bags, seroons, and mats the short trier shall be used, care
being exercised to have each sample represent the contents of the package. The
greatest precaution shall be taken that the samples from each class of packages
shall be kept separate and be uniform in quantity.
Art. 723. Detail of samplers.—At ports where the number of samplers employed
will permit, no sampler shall be detailed in the same sugar district or on the same
dock longer than one month. A complete record of the assignment of the ex-
aminers and samplers shall be kept and shall be approved by the appraiser.
Art. 724. Discharge from lighters.-Sugars conveyed on lighters from the place
of original discharge before samples have been taken shall not be removed there-
from until notice of the time of their proposed removal has been given by the
inspector to the examiner or sampler in charge.
Art. 725. Sampling from lighters.—In cases where vessels discharge in one dis-
trict and the sugars are lightered to another before sampling, the manifest which
accompanied the lighter and is delivered to the inspector in charge of the district
where such sugars are to be weighed and sampled shall be presented to the ex-
aminer or sampler in charge for his indorsement, the same as in the case of an
Original permit and such manifest shall show the name of the person making entry.
The inspector in charge of such district shall be held responsible for the treatment
of all such sugars under these regulations, the same as if working under the
Original permit. -
Art. 726. Transfer of samples.—All sugar samples drawn on any given half day
shall reach the examining room in the appraiser’s stores not later than the close
of the first official half day following, except where the place of discharge is more
than 15 miles distant from the appraiser's stores. Whenever practicable the
samples for each half day will be forwarded to the appraiser's stores as soon as
the half day is completed. When sugars are discharged at places where the dis-
tance makes it impracticable for the regular conveyance to call for the samples,
and where special provision is made by contract for other means of transporta-
tion, an official shall be detailed by the appraiser to take charge of such sample
until they reach the appraiser’s stores.
Art. 727. Refined sugars.—In sampling receptacles containing refined sugars
the percentage to be sampled shall be determined by the best judgment of the
examiner or sampler in charge. Every precaution shall be taken to have the
sample fairly and adequately represent the shipment.
Art. 728. Care of sampling equipment.—The utmost care must be taken to keep
all the apparatus used in the process of sampling sugar clean and absolutely dry.
Suitable cleaning and polishing materials shall be supplied to the samplers, who
are hereby instructed to always have their implements in perfect condition.
The sampler shall frequently and thoroughly clean his trier with a scraper provided
for that purpose. Failure to observe these requirements shall be reported at
Once to the appraiser by the examiner or the sampler in charge, and such failure
will be regarded as sufficient cause for suspension.
Art. 729. Sugar discharged during storm.–Sugar discharged during a rain or
snow storm shall be sampled under cover. When this is impracticable, or if in
the judgment of the appraiser fair samples cannot be obtained by reason of the
stress of weather, or for any other reason, the inspector shall immediately stop
the discharge of the cargo. In the absence of the inspector the appraiser shall
immediately take such steps as may be necessary to stop the discharge of the
Cargo. -
Art. 730. Buckets for sirup and molasses samples.—The receptacle used in col-
lecting all molasses samples shall be the standard sugar bucket, and the regula-
tions governing the use of this bucket in the collection of sugar shall apply with
equal force when it is used for the collection of molasses.
Art. 731. Molasses and sirups—Better grades (T. D. 36195).-In sampling all grades
of sirups and molasses other than blackstrap, 100 percent of the packages shall be
sampled. The contents of each receptacle shall be thoroughly stirred in order
that any settlings shall be evenly distributed and the contents brought to as
uniform a density as possible. Receptacles of the same size shall be sampled in
groups of not more than 25, a sample of uniform quantity being drawn from each.
A tally shall be kept and the label thereon shall show the number of packages
which each bucket represents. The dock list accompanying the sample buckets
shall convey the same information and shall account for every package of the
788 Circular of the National Bureau of Standards
mark. Packages of different size or character of contents, although invoiced
and permitted under the same mark, shall be separately sampled, tested, and
classified. If any package or packages shall, in the judgment of the sampling
Officer, have the appearance of sirup of cane juice, or of testing by the polariscope
above 50 sugar degrees, a separate sample of same shall be taken.
Art. 732. Blackstrap molasses.—When blackstrap (frequently designated waste
molasses) is imported in barrels, 10 percent of all the receptacles shall be sampled.
When, in the judgment of the examiner or sampler in charge, a greater percentage
is necessary to fairly represent the importation, such additional barrels shall be
Sampled as, in his judgment, are necessary to secure a representative sample.
Blackstrap imported in tank vessels shall be sampled as it is being pumped from
the vessel. Samples of uniform quantity, in general one-half liter, shall be drawn
with such frequency as to insure one sample for each 5,000 gallons.
Art. 733. Molasses in tank cars.--Molasses in tank cars shall be sampled by
drawing two similar complete samples of about 1 liter each and consisting of a
continuous portion or core extending from the top to the bottom of the tank.
When for any reason such a core cannot be obtained, the two complete samples
shall each consist of three portions: One portion from the top just below the surface
of the liquid, one from the center, and one from the bottom of the tank. All
samples shall be forwarded to the appraiser with the least possible delay.
Art. 734. Sugar closets.—Sugar closets in the sugar districts shall be sub-
stantially built, and secured by locks furnished by the Department. They shall
be conveniently located as near as possible to the points of discharge they are
intended to serve. They shall be provided by the owner of the premises on which
they are located and shall be so situated that sugar, sirup, and molasses stored
therein shall not be subjected to extremes of temperature or humidity.
TESTING OF SUGARS, SIRUPS, AND MOLASSES
Art. 735. Mizing of sugar samples.—The mixing and preparing of samples for
test shall be done at the appraiser’s stores under the supervision of the examiner
of sugar. Samples shall be mixed and forwarded to the laboratory as soon as
possible after their arrival at the appraiser’s stores. Under no circumstances
shall the contents of more than three sugar buckets be mixed together. The
mixing shall be performed on heavy paper with a glossy surface which will not
readily absorb moisture, or on a table with a metal top. The samples shall be
passed through a wire screen of about 3%-inch mesh set in a galvanized-iron frame
with inclosed sides. Great care shall be exercised to obtain a uniform mixture,
but the operation shall be expedited so as to avoid unnecessary exposure to the
atmosphere.
Art. 736. Sugar cans.—The tin cans used in transmitting the samples to the
laboratories for polariscopic test shall have a height of 11.5 centimeters and a
diameter of 8 centimeters. They shall be practically airtight, the seamless lid
fitting snugly over the rim, which is topped by a seamless band. No cans shall be
used for this purpose that have not been made on the dies owned by the Depart-
ment. All cans must be clean and dry before using. Frequent inspection shall
be made to prevent the use of any can having loose or ill-fitting lid or broken
seams on side or bottom. All damaged cans shall be discarded.
Art. 737. Preparation of sugar samples.—From the sample prepared by mixing
the contents of not more than three buckets, duplicate samples shall be prepared
by closely packing two tin cans full of sugar and transmitted forthwith to the
laboratory for polariscopic test. Where the port of importation has no customs
laboratory, the prepared samples shall be transmitted forthwith to the chief
chemist of the customs laboratory designated in article 12 and the cans of samples
shall be firmly packed full of sugar and sealed airtight with paraffin. A third
portion, consisting of about three pounds, shall be placed in a glass jar to constitute
a reserve sample. In all cases the jars must be firmly packed full of sugar before
closing and so sealed as to make them airtight. Such samples, after being properly
labeled for identification, shall be held in safe custody by the appraiser for use
when required.
Art. 738. Identification of samples.—In transmitting the samples from the
examiner's room to the laboratory they shall be indicated only by serial numbers,
the key to which shall consist of the appraisement lists, on which the same num-
bers must appear, and the laboratory officers shall not be informed in any manner
as to the identity of such samples. Appraisement lists shall be made out in dupli-
cate, an original and carbon copy, the latter to be filed in the order of the sample
serial numbers for reference if required. Sample serial numbers shall begin with
No. 1 at the beginning of each year and continue throughout the year, and all
numbers shall be accounted for in the records specified.
Polarimetry, Saccharimetry, and the Sugars 789
Art. 739. Recording of sugar tests.-A complete test shall be made of each sample
sent to the laboratory. The accepted tests reported by the chemist in charge
shall be entered in red ink on the original appraisement lists, together with the
accepted tests of the duplicate samples. Should the accepted tests of duplicate
samples provided for in article 738 be 92° S (sugar degrees) or above and should
they agree within 0.2° S, the average of the two shall be taken as the true polari-
scopic test of the sugar. If one or both of the polarizations should be less than
92° S, and they agree within 0.3° S, the average of the two shall be taken as the
true polariscopic test of the sugar.
Art. 740. Use of reserve sugar sample.—When the accepted tests of the two
samples do not agree as provided in article 739, a third sample, to be known as
the reserve sample, shall be made up from the reserve portion, and treated as a
regular sample. When preparing samples for the laboratory from the reserve
jars the entire contents shall be taken out and remixed in order that the moisture
may again be evenly distributed throughout the sample. The tests of the reserve
sample having been duly recorded, the accepted tests of the three samples shall
be considered together. Of the three separate tests so recorded, the average of
the two most closely corresponding shall be taken as the test of the sugar; but
if one of the said tests be the average of the other two it shall be taken as the
correct test.
Art. 741. Sugar test for classification.— (a) The test for classification shall be
an average of tests based upon the number of packages which each accepted test
represents. This number shall be determined by proportioning the number of
packages weighed each half day over the different mixings for such half day
according to the number of cans of samples received, using the reports of the
weigher, provided for in article 703, for that purpose. Such average shall be
carried to five places of decimals.
(b) Wet sugar, damaged sugar not wet, ship sweepings, dock sweepings, or any
other sugar required under these regulations to be sampled separately, shall be
classified and the tests averaged in the same manner as the general cargo.
Art. 742. Retests of sugar.— (a) When the test of the sugar has been determined
the appraiser shall immediately notify the importer of the average test of the
importation and also the quantity and test of each lot from which such average
test is obtained. Should be importer, within 2 official days after such notice has
been sent to him by the appraiser, claim an error in the test so reported and
request a retest, such retest may be granted, provided, on evidence furnished,
such claim shall appear to the appraiser to be well founded. Before granting
retest the appraiser shall require of the importer any information he may deem
desirable relative to the samples and polarizations used in the settlement tests.
Before any sugar invoice is passed the appraiser shall require the importer to fur-
nish the settlement tests, and in no instance shall a retest be granted when the
difference between the appraiser's test and the settlement test is shown to be less
than 0.4° S. Samples for retest shall be made up from the reserve sample and
shall be treated in all respects as provided for the original tests.
(b) All requests for retests of sugar shall be properly filed and a record thereof
shall be kept by the appraiser on customs form 6467.
Art. 743. Classification when retest is made.—In case of retest made under the
provisions of article 742, the test upon which the sugar shall be classified shall be
the average of the test and the retest unless it can be shown to the satisfaction of
the appraiser that either the test or the retest is in error, in which event the test
not in error shall be taken as the basis of classification.
Art. 744. Error in original test.—In all cases where in the judgment of the
appraiser an error has been made the reserve sample may be resorted to by the
appraiser at any time before he has made his return on the invoice for the purpose
of determining and correcting such error.
Art. 745. Molasses and sirup samples—Preparation and recording of tests (T. Ds.
31763, 31935).-(a) All the molasses and sirup samples from an individual im-
portation, when uniform in character, shall in general be represented by not more
than two composite laboratory samples each sample representing one-half of the
importation. Whenever practicable, a single composite sample shall be made to
represent the importation. When, however, any such samples are not uniform in
character, or when separate samples have been returned pursuant to article 732,
as many separate samples shall be sent to the laboratory for test as, in the judg-
ment of the examiner, shall be necessary to correctly classify the different grades
of material in the importation.
(b) Two duplicate samples of approximately one-half liter from each composite
sample shall be forwarded with the least possible delay to the laboratory for test.
790 Circular of the National Bureau of Standards
At least 1 liter of each composite sample shall be retained as a reserve sample.
The average of the tests of the duplicate samples shall be the accepted test of the
composite sample provided they do not differ by more than five-tenths percent
total sugars.
(c) The contents of each bucket of molasses or sirup samples shall be stirred in
Such a manner as to evenly distribute any sugar sediment that may have settled to
the bottom and the contents brought to as even a density as possible.
(d) The recording and averaging of accepted tests of duplicate samples shall
be, unless otherwise provided for in these regulations, the same as for sugar.
Molasses and sirup samples shall be labeled with customs form 6479 showing the
following information: Invoice designation; entry number; marks; place and
date of sampling, Sampler; entered paragraph and rate; origin; also, when shown
On the customs invoice, the percentage by weight of total soluble solids (or Brix)
and the percentage by weight of total sugars.
(f) Molasses and sirup samples shall be handled as expeditiously as possible
in order that they may not be affected by fermentation and shall be given a serial
number that will insure as early a test as possible.
Art. 746. Molasses and sirup test for classification.—The test for classification
of a molasses or sirup importation shall be the average of the accepted tests for
the composite samples based upon the proportion of the entire lot which each
composite sample represents.
Art. 747. Molasses and sirup—Significance of test—Retest (T. D. 397.10).-Owing
to the unstable character of molasses and sirup, the results of any retest cannot
have, from the standpoint of correctness for appraisement purposes, the same
significance which the results of a retest on sugar possess. A retest shall be
granted by the appraiser only when the information in his possession indicates a
strong probability of an error. The regulation governing the granting of a retest
shall in general be that given in article 743, with the exception that the difference
between the appraiser's test and the settlement test shall be shown to be not less
than 2 percent total sugars.
Art. 748. Notice to importer.—When an invoice of sugar, molasses or sirup has
been passed, the appraiser shall at once send written notice to the importer, in-
forming him of the test for classification of his importation.
Art. 749. Sugar records—Filing.—The original appraisement lists for each cargo,
with dock lists, weighers’ reports, letters of transmittal, and any other informa-
tion relating to the same, shall be filed together as a permanent record, under
serial numbers, an index to which shall be kept in a permanent form as a means
of ready reference. All chemists’ reports of tests shall be filed in the order of the
sample serial numbers for reference when required.
Art. 750. Procedure for eacchange samples.— (a) Each day, except as provided for
in paragraph (b), when imported sugar is sampled for test at any port, the ap-
praiser shall prepare a duplicate of one of the regular laboratory samples referred
to in article 737 and forward the duplicate to the Director of the National Bureau
of Standards. The sample sent to the customs laboratory shall be tested as soon
as it is received and the separate tests, together with the accepted test, shall be
immediately reported, under the identifying marks by the appraiser at the port
where the samples were mixed for testing, to the Director of the National Bureau
of Standards on customs form 6473. The report on customs form 6473 for all
ports shall show the polarization. On Firdays at each of the ports of Baltimore,
Boston, New Orleans, New York, Philadelphia, Savannah, San Francisco, Los
Angeles, and Chicago, the exchange sample sent to the customs laboratory and
the duplicate sent to the National Bureau of Standards shall each be designated
“dry”, and the report on form 6473 shall show, in addition to the polarization,
the percent of moisture and the polarization of the dry substance.
(b) On Monday of each week each appraiser at Baltimore, Boston, New Or-
leans, New York, Philadelphia, and Savannah shall prepare a sample of sugar for
test in the customs laboratory at his port, and a duplicate of the same sample
shall be forwarded to each of the other appraisers at the above-named ports and
to the Director of the National Bureau of Standards. Upon receipt of a duplicate
exchange sample at a port, it shall be entered in a special record, after which the
identifying marks shall be carefully removed and the sample delivered to the
customs laboratory under its serial number. The sample shall be tested as Soon
as it is received and the separate tests, together with the accepted test, shall be
immediately reported by the appraiser under the identifying marks to the Director
of the National Bureau of Standards on customs form 6473. A copy of this re-
port shall be forwarded at the same time to the Commissioner of Customs. The
report on customs form 6473 shall show the polarization.
Polarimetry, Saccharimetry, and the Sugars 791
(c) Each sample shall be forwarded in the tin can prescribed in article 736,
which shall be firmly packed full of sugar and sealed airtight with paraffin. The
samples shall be numbered at each port of importation from 1 upward, beginning
with the first official day in each calendar year, and the duplicates shall be marked
for identification with the same number, the name of the importing port, and the
date of the test at such port. A complete record of sample tests shall be kept on
customs form 6481.
(d) All requests by the Director of the National Bureau of Standards (Depart-
ment of Commerce form 558) for retests of the polarization or of the polarization
of the dry substance of samples shall be immediately complied with. The retests
shall be completed not later than the close of the first official day after the receipt
of the request, and the results immediately forwarded by the appraiser On customs
form 6473. When, for any reason, the retests requested are not completed by
the close of the first official day after the receipt of the request, the retests shall
not be made and the appraiser shall furnish the Commissioner of Customs with
a detailed statement why said retests were not made as herein provided.
Art. 751. Molasses and sirup eacchange samples.—Once each month, when im-
ported molasses or sirups are sampled for test at any port, the appraiser shall
prepare a duplicate of a sample sent to the customs laboratory designated in
article 12 and forward the duplicate half-liter sample, properly numbered and
labeled, to the Director of the National Bureau of Standards for test. A copy
of the customs laboratory report, customs form 6415, shall be promptly forwarded
to the Director of the National Bureau of Standards by the appraiser of the
port where the molasses was mixed for transmission to the laboratory. The
report shall show separately the percent sucrose, the percent reducing Sugars,
the percent total sugars, the percent nonsugar solids in total soluble solids, and
the weight per gallon in air at 20° C. The samples shall be numbered at each port
of importation from 1 upward, beginning with January 1 of each year, and the
duplicates shall be marked for identification with the same number, the name
of the importing port, and the date on which the sample was prepared. The
samples shall be transmitted in screw-top metal containers. A reserve portion
of each such sample, consisting of not less than one-half liter, shall be retained
by the appraiser for retest purposes. All requests by the Director of the National
Bureau of Standards for retests shall be promptly complied with.
Art. 755. Adulterated refined sugars.--When refined sugars, including all sugars
other than raw sugars, are imported at any port, samples shall be forwarded to
the customs laboratory designated in article 12 to determine whether, after
having been refined, they were tinctured, colored, or in any way adulterated. A
duplicate of each such sample sent to the customs laboratory shall be forwarded
at the same time to the National Bureau of Standards. Each sample sent to the
customs laboratory and each duplicate sent to the National Bureau of Standards
shall be placed in the sugar can described in article 736 and labeled with customs
form 6479. The cans shall be firmly packed full of sugar and sealed airtight with
paraffin. A copy of each customs laboratory report on such samples shall be
transmitted to the National Bureau of Standards.
Art. 756. Preservation of sugar samples.—All samples of sugar sent to the
laboratory for test must be preserved as nearly as possible in the same condition
as when received, and shall be returned therefrom to the examining room in Such
condition. All samples tested for exchange and all exchange samples, as SOOn
as they have been returned from the laboratory, shall be labeled with their
identifying marks, securely sealed airtight, and held in safe custody in the ex-
amining room 30 days from the date of test for such further test or investigation
as may be ordered by the Director of the Bureau of Standards. In case any
exchange samples have been received at any port not properly filled and sealed
as herein prescribed, the appraiser at the port of receipt shall immediately notify
the appraiser at the port of transmittal, and shall also report the facts to the
Director of the Bureau of Standards.
Art. 757. Care of apparatus.—All screens used in the mixing of samples, sample
buckets, sample cans, reserve jars, etc., when once used, shall be thoroughly
washed, dried, and allowed to cool before being used a second time.
Art. 758. Admission to eacamining rooms.—All persons shall be denied admission
to the examining rooms of the appraiser’s office except officers and employees
whose ques require them to have access thereto. This provision must be strictly
enforced.
Art. 759. Interpretation of “testing by the polariscope.” The expression “testing
by the polariscope * * * Sugar degrees”, occurring in a tariff act, shall be
construed to mean the percentage of sucrose contained in the Sugar shown by
direct polarimetric estimation.
y 5
792 Circular of the National Bureau of Standards
Art. 760. Total sugars defined.—The expression “total sugars”, occurring in the
tariff act, shall be construed to mean the sum of the sucrose (Clerget), the raffinose,
and the reducing sugars.
Art. 761. Laboratory records.-A permanent record of all samples received from
the examiner shall be kept in the laboratory. The samples shall be identified
therein by their serial numbers arranged in the order in which they are received.
It shall be the duty of the chemist in charge to report the results of all tests of
such samples made and recorded, severally, including the third and fourth tests,
When made, to the assistant appraiser or examiner in charge of classifications.
LABORATORY PROCEDURE FOR SUGARS, SIRUPS, AND MOLASSES
Reprinted from Customs Regulations of 1931, Articles 741–756, inclusive and Articles 758–763, inclusive
Arrangement of laboratories.—Plans for laboratories for the testing of sugar and
molasses must be approved by the Commissioner of Customs. The room used
for the purpose shall be one that is as far removed as possible from the vibration
of machinery; it must be well lighted and have some means of artificial heat, so
that the temperature may be controlled, and shall not be too near any source of
heat which cannot be controlled. The polariscopes shall be placed in the darkest
portion of the room whenever possible, and the top of the table upon which they
are placed shall be surrounded on three sides by blackened partitions or walls not
less than 3 feet in height. If necessary, suitable curtains may be hung around the
polariscope to exclude extraneous light. The surroundings of the polariscope
shall be such as always to permit the air from the remainder of the room to
circulate around the instruments with the greatest freedom. The separation of
the lamp from the instruments will be accomplished by the wall around the top
of the table. The opening in the partition between the lamp and the instrument
shall be as small as possible and yet allow sufficient light for the proper illumination
of the polariscope. The polariscope shall not be near ovens, assay furnaces,
hot-water heaters, or any other source of heat.
Standardized apparatus.--All thermometers, flasks, weights, polariscope tubes,
polariscope-tube cover glasses, quartz control plates, and polariscopes, used in
the work of testing sugar, shall be standardized at the Bureau of Standards,
Department of Commerce, and with the exception of the polariscope-tube cover
glasses and weights, shall be marked with the initials “U. S. C. S.”, and bear the
stamp of the Bureau of Standards. No test of sugar shall be made with apparatus
which is not properly marked unless special authority is given by the Secretary
of the Treasury.
Standardization temperature.—All the apparatus used in the work of testing
sugar by the polariscope shall be standardized at a temperature of 20° C.
Thermometers.--All thermometers shall have the centigrade scale and be
graduated to one-fifth of a degree or less.
Sugar flasks.-(a) The flasks shall have a height of 130 mm.; the neck shall be
70 mm. in length and have an internal diameter of not less than 11.5 mm and
not more than 12.5 mm. The upper end of the neck shall be flared, and the grad-
uation marks shall be not less than 30 mm. from the upper end and 15 mm. from
the lower end of the neck.
(b) All flasks shall be standardized to contain 100 ml. at 20° C. The glass
funnels used in filtering shall have a diameter of approximately 90 mm. The
cylinders shall have a height of approximately 125 mm. and a diameter of ap-
proximately 40 mm.
Laboratory weights.-Only brass weights shall be used, and they shall be for-
warded to the National Bureau of Standards for standardizing not less than once
a year. A sufficient number of standardized duplicate weights shall be kept in
reserve in each laboratory to take the place of those being standardized.
Polariscope tubes.—The length of all polariscope tubes shall be either 100
+ 0.03 mm. or 200 + 0.03 mm., and the diameter of the opening through the tube
shall be not less than 9 mm. No tube shall be retained in use that has become
bent or dented or has had its threads injured sufficiently to make the adjustment
of the cap difficult.
Quartz control plates.—All quartz control plates shall be mounted in a brass
retaining box, which shall exert no pressure whatever upon the plate and yet
allow it minimum play. Each plate will be accompanied by a table, signed by the
Director of the Bureau of Standards, giving its exact value at different tempera-
tures from 15° to 35° C.
Standard sugar solution.—All polariscopes shall be so standardized that when a
200-mm. tube filled with the standard sugar solution is polarized at 20° C. the
instrument shall read 100° -- 0.01° S. All points on the scale shall indicate per-
Polarimetry, Saccharimetry, and the Sugars 793
centages of the standard solution. The standard sugar solution shall be prepared
by dissolving 26 g. of pure sugar in pure water and making up the volume to 100
ml., all weighings to be made in air with brass weights and the volume to be com-
pleted at 20° C. A length of 200 mm. of the standard sugar solution shall be
considered to give a rotation of 40.763° for light of wave length 5461 × 10−8 cm.
Polariscopes and their adjustment.— (a) All polariscopes used in the testing of
imported sugars shall have a double quartz-wedge compensation and a polarizing
system known as the Lippich half shadow. The field of the polariscope shall
be divided into halves by a vertical line, and in no instance shall a reading of the
scale be made unless, in the opinion of the observer, the halves are of exactly
equal intensity.
(b) If, when the polariscope is empty and the halves of the field matched, the
zero of the movable scale shall fail to correspond with the zero of the vernier by
more than 0.3° S (sugar degrees), they shall be made to coincide by turning the
small nipple on the left-hand side of the instrument.
(c) In testing the instrument by means of the quartz control plate, not less than
four careful readings shall be made. After the average of these readings has
been corrected for the error in the zero point, it should equal the value stamped
upon the plate within 0.05% S. If such is not the case the polariscope shall be
readjusted until the difference is not greater than 0.05% S.
(d) When taking the reading on the quartz control plate the deviation of the
zero point shall be neglected after the instrument has been found to be accurately
adjusted. The total correction for the instrument shall then be found by means
of the table accompanying the plate and the reading of a thermometer placed close
to the polariscope.
(e) The method of determining and applying the total correction shall be as
follows: Let a sugar solution polarize 95.55° S. The control plate had polarized
99.95° S. The temperature of the room during both observations was 25° C.
From the table the value of the control plate at 25° C. is 100.25° S. The reading
is therefore 0.30 too low and 0.30 shall be added to the reading of the sugar solution,
making the corrected polarization 95.85° S.
(f) The zeros of the upper scale and its vernier shall be kept in exact coincidence
and the scale securely clamped in that position.
Polariscope light source—Bichromate cell.— (a) The source of light may be either
an incandescent gas mantle or white-light electric lamp constructed according to
the specification of the Bureau of Standards. The radiating source shall not be
less than 200 mm. distant from the polarizing end, the best position of the source
being determined by carefully adjusting it back and forth until the illumination
of the field is absolutely uniform and a maximum.
(b) The radiation from all white-light sources shall be filtered through a solution
of potassium bichromate before it enters the polariscope. This solution shall be
contained in a glass cell, placed as near as possible to the polarizing end of the
instrument. The cell shall have parallel walls with an inside separation of 15 mm.
The concentration of the solution shall be 6 percent. If, for any reason, it should
be necessary to use a cell which does not give a layer of liquid 15 mm. thick, the
concentration must be so altered that the product of the thickness in millimeters
of the absorbing solution and the concentration, in percent, shall equal 90.
Preparation of the sugar solution.—After the can of sugar referred to in article
737 48 above has reached the laboratory its contents shall be thoroughly mixed
while in the can by stirring with a spoon just before the weighing is made. In
case the sugar contains hard lumps not readily crushed and mixed by stirring, it
shall be mixed in a mortar or by other adequate means. In case of sugar products
in liquid form, such as sirup of cane juice and mixtures containing sugar and water,
the sample shall be thoroughly mixed to insure uniformity. If sugar crystals
have separated out, they must be redissolved by placing the sample in a water
bath at approximately 50° C. Care must be exercised to prevent undue evapora-
tion during the heating, mixing, and in the weighing of the sample for analysis.
After mixing, 26 g. are weighed on the balance in the tared German-silver dish
furnished for this purpose. Care must be taken that the operations of mixing
and weighing are not unduly prolonged; otherwise the sample may easily undergo
a change in the moisture content. The weighed portion of sugar is washed by
means of a jet of water into a 100-ml flask, the dish being well rinsed three or
four times and the rinsings added to the contents of the flask. The water used
must be either distilled water or clear water, which has been found to have no
optical activity. After the dish has been thoroughly rinsed, enough water is
added to bring the contents of the flask to about 60 ml., and it is gently rotated
48 Article 737, Customs Regulations of 1937.
794 Circular of the National Bureau of Standards
until all the sugar is dissolved. The flask shall be held by the neck and the bulb
not handled during this operation. A proper mechanical shaking device may be
used in place of hand shaking. Care must be taken that no particle of the sugar
or solution is lost. To determine whether all the sugar is dissolved, the flask is
held above the level of the eye, in which position any undissolved crystals can be
easily seen at the bottom. The character of the solution is now observed. If it
be colorless, or of a very light straw color, and not opalescent so that it will give
a clear, transparent liquid on filtration through paper, the volume shall be made
up directly with water to the 100-ml mark on the flask.
Use of basic lead acetate.—(a) If a clear, transparent liquid is not obtained, a
clarifying agent shall be added In that event, before making up to the mark a
solution of basic acetate of lead is added, which is prepared by boiling 3 parts by
weight of acetate of lead, 1 part by weight of oxide of lead, and 10 parts by weight
of water until the reaction is complete. The filtered solution should have a density
of about 1.25. Solid basic acetate of lead may be substituted for the normal salt
and oxide in the preparation of the solution.
(b) After adding the solution of basic acetate of lead the flask must be gently
shaken, so as to mix it with the water solution. If the proper amount has been
added, the precipitate will usually subside rapidly; but if not, the operator may
judge of the completeness of the precipitation by holding the flask above the level
of the eye and allowing an additional drop of basic acetate of lead to flow down
the side of the flask into the solution. If this drop leaves a clear track along the
glass through the solution, it indicates that the precipitation is complete. If, on
the other hand, all trace of the drop is lost on entering the solution, it indicates
that an additional small quantity of the basic acetate of lead is required. The
operator must learn by experience the point where the addition should cease;
an excess of basic acetate of lead solution should never be used.
Making up to volume and filtering.— (a) The solution shall be made up to the
mark by the addition of distilled water in the following manner: The flask, grasped
by the neck between the thumb and finger, shall be held before the operator in
an upright position, so that the mark is at the level of the eye, and water is added,
drop by drop, from a siphon bottle or wash bottle until the lowest point of the
curve or meniscus formed by the surface of the liquid just touches the mark. If
bubbles hinder the operation, they may be broken up by adding a single drop of
ether or a spray from an alcohol atomizer before making up to the mark. After
making up to volume, drops of water adhering to the neck above the meniscus
shall be removed. The mouth of the flask shall be tightly closed with the thumb,
and the contents of the flask shall be thoroughly mixed by turning and shaking.
The entire solution shall be poured upon the filter.
(b) The funnel and the vessel used to receive the filtrate must be perfectly dry.
The first portion of the filtrate, about 20 to 30 ml, should be rejected entirely. It
may be necessary to return subsequent portions to the filter until the Jiquid passes
through perfectly clear.
(c) lf a satisfactory clarification has not been obtained, the entire operation
must be repeated, since only with solutions that are entirely clear and bright can
accurate polarimetric observations be made.
Filling and handling of polariscope tube. —When a sufficient quantity of the clear
liquid has passed through the filter the 200-mm polariscope tube shall be filled
with it. The 100-mm tube should never be used except in the rare cases when,
notwithstanding all the means used to effect the proper decolorization of the solu-
tion, it is still too dark to polarize in the 200-mm tube. ln such cases the shorter
tube may be used and its reading multiplied by 2, but the zero deviation must
then be determined and applied to the product. This will give the reading which
would have been obtained if a 200-mm tube could have been used, and it only
remains to apply the correction determined by the use of the control plate.
Eacample
Solution reads in 100-mm tube. -------------------------------------------- 47. ()
Multiplied by 2------------------------------------------------------------ 2. 0
Product --------------------------------------------------------------- 94. 0
Zero reads plus 0.3--------------------------------------------------------- ... 3
Solution would read in 200-mm tube---------------------------------------- 93.7
Reading of control plate--------------------------------------------------- 90.4
Sugar value of Control plate- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ------ 90. 5
Scale reading too low by ------------- --------------------------------------- . 1
Add 0.1 to 93.7. -
Correct polarization of Solution.-------------------- - - - 93.8
Polarimetry, Saccharimetry, and the Sugars 795
Before filling the tube it must either be thoroughly washed and dried or rinsed
several times with a portion of the solution itself. The cover glasses must also
be clean and dry and without serious defects or scratches. Under no circum-
stances, after sufficient liquid has passed through the filter, shall more than 12
minutes elapse before the tube is filled. Unnecessary warming of the tube by
the hands during the filling must be avoided. It is closed at one end with the
screw cap and cover glass and grasped by the other end with the thumb and finger.
The solution shall then be poured in until the tube is nearly filled, leaving space
for an air bubble when the cover glass is in place. The air bubble shall be as large
as possible without being visible when the tube is held in a horizontal position.
Care shall be taken that the outside portion of the cover glasses remain clean and
dried. If this result is not attained, the operation shall be repeated, the cover
glass being washed clean and dry and the solution again brought up over the end
by adding a few more drops. The cover glass being in position, the tube shall
be closed by screwing on the cap. The greatest care must be observed in screwing
down the caps that they do not press too tightly upon the cover glasses. By such
pressure the glasses themselves may become optically active and cause erroneous
readings when placed in the instrument. It shall therefore be ascertained or
made sure that the rubber washers are in position over the cover glasses and the
caps shall be screwed on lightly. A cover glass that has once been compressed
may part with its acquired optical activity very slowly and not less than 7 official
days shall be allowed to elapse before it is used again.
Polarizing sugar.—Before the polariscopic reading on the polariscope tube shall
be taken, an observation on the quartz control plate shall be made. The tube
must be read without altering the position of the instrument relative to the light
Or changing the character of the light in any way. When a series of successive
polarizations is made under the same conditions as regards temperature, position
of the instrument with relation to the light, intensity of the light, etc., the obser-
Vation On the control plate need not be made before each polarization; one such
Observation shall be sufficient for the entire series. The control observation
must be repeated oftener if the observer has the slightest reason to think that any
of the factors just indicated have been altered. After the polariscope tube has
been placed in the polariscope, the observing telescope shall be so adjusted as to
bring the dividing line between the two halves of the field into sharp focus and
at the same time cause it to vanish as nearly as possible. This condition must be
carefully fulfilled before any observation is taken. Each polariscope tube shall
be read on two different instruments by the same observer, and not less than three
careful readings of the tube shall be made on each instrument. After the average
of these three readings has been corrected by means of the quartz control plate,
it shall be taken as the polarization of the tube on that polariscope. The average
of the two averages obtained from the two polariscopes shall be taken as the
final polarization of the tube.
Determination of sucrose in came sirups and molasses.—The method for the
determination of sucrose in cane sirups and molasses shall be as follows: Prepare
a solution of the molasses containing 65 g in 500 ml (half-normal), 26 g in 250 ml
(two-fifths normal), or 13 g in 250 ml (one-fifth normal), according to the nature
of the substance. Make to volume at the temperature at which the polariscopic
observations are to be made, clarify with the minimum quantity of Horne's dry
basic lead acetate, and shake thoroughly. Filter.
Pipette two 75-ml portions of the clear filtrate into two 100-ml volumetric
flasks.
Direct polarization.—To 1 portion add 10 ml of a solution of sodium chloride
containing 231.5 g per liter. Make to volume at the temperature at which the
polariscopic observations are to be made. Shake and filter as rapidly as possible
in order to avoid resolution of lead chloride. Polarize.
Invert polarization.—To the other portion add 10 ml of hydrochloric acid
(d 20°/4°, 1.1029). Immerse in a water bath which is maintained at 60° C.
Agitate the solution continually for 3 minutes and allow it to remain in the bath
for a total time of 10 minutes. Cool quickly and make to volume at the tempera-
ture at which the observations are to be made. Shake and filter as rapidly as
possible. Polarize.
All polarizations shall be made in water-jacketed tubes provided with tubulature
and thermometer.
Correct both readings for zero point displacement. Take the algebraic differ-
ence between the direct and invert polarizations and convert to 26 g basis by
multiplying by 8/3, 10/3, or 20/3, according to the normality of the original
solution. This gives the value P-P' to be used in the final calculation.
796 Circular of the National Bureau of Standards
In order to find the proper Clerget divisor, P-P’ is multiplied by the normality
fraction of the original solution, i. e., 1/2, 2/5, or 1/5. From table 19, National
Bureau of Standards Scientific Paper S375, page 189, under the column marked
“75 ml X 4/3” and opposite the value of P−P' (reduced by the normality fraction),
find the value of the Clerget divisor. Apply the temperature correction and
divide into Pi—P/1.
The pipetting of Solutions shall be done with great care. The pipettes must be
kept scrupulously clean by frequent use of a bichromate sulfuric acid cleaning
mixture, the lead being first removed with alkaline tartrate solution. During
delivery it shall be held in a vertical position and allowed to drain by gravity for
the definite length of time specified by the calibration.
It is advisable to perform the direct and invert polarizations for each analysis
during the same series of observations, placing the tubes side by side and feeding
the water jackets from the same source.
The hydrochloric acid (d 20°/4°, 1.1029) is made by diluting the concentrated
cp acid by approximately an equal volume of water. It is sufficiently accurate
to adjust the diluted solution to a density of 24.9 Brix at 20.0° C.
Determination of reducing sugars in came sirups and molasses.—The method for
the determination of the reducing sugars in cane sirups and molasses containing
approximately 50 percent total sugars shall be as follows: Eight grams of
molasses are transferred to a 500-ml flask, dissolved, clarified with a minimum
quantity of normal lead acetate solution and made to volume and filtered. The
filtrate is freed from excess of lead by the addition of dry potassium oxalate.
Aliquot portions of 50 ml of the lead-free filtrate are taken for analysis. Transfer
25 ml each of solutions A and B of the Soxhlet reagent to a 400-ml beaker and
add 50 ml of the above solution. Heat the beaker upon an asbestos gauze over a
Bunsen burner, so regulating the flame that boiling begins in 4 minutes and con-
tinues boiling for exactly 2 minutes. Keep the beaker covered with a watch
glass throughout the entire time of heating. Without diluting, filter the cuprous
oxide at once on a Gooch crucible, using suction. Wash the cuprous oxide thor-
oughly with water at a temperature of about 60° C, then with 10 ml of alcohol,
and dry for 15 minutes in an oven at 100° C. Ignite crucible for 10 minutes
over a Bunsen burner. The precipitate is reduced to metallic copper in methyl
alcohol vapors. This is done by placing about 15 ml of methyl alcohol in a
400 ml beaker, placing a triangle support in the beaker so the top is above the
level of the alcohol. Heat covered beaker to boiling on hot plate; remove cover
and place hot Gooch crucible on triangle. This ignites the alcohol vapors.
Immediately cover with watch glass and allow to remain for about 6 minutes,
remove, dry in an oven at 100° C for about 5 minutes, cool in desiccator, and
weigh. The amount of reducing sugar corresponding to this weight of copper is
found from table 78, p. 564 (column marked “0.4 g total sugar"). .
Control determinations should be carried out, using standard dextrose. In the
event that the percentage of total sugars in the molasses varies appreciably from
50 percent, such a weight is taken for the reducing-sugar determination, that 50
ml of the solution will contain 0.4 or 0.3 g total sugar to conform to the specifica-
tions of the method of Munson and Walker.
Example.—In a sirup containing 80 percent of total sugars, 5 g of the sample
are dissolved and made up to 500 ml, and 50-ml portions taken for analysis, each
such portion containing 0.5 g of sample or 0.4 g of total sugars.
Determination of sucrose and raffinose in beet molasses.—The method for the
determination of the sucrose and raffinose in beet molasses shall be as follows:
Prepare a solution of the beet molasses containing 65 g in 500 ml (half normal).
Make to volume at the temperature at which the polariscopic observations are to
be made. Clarify with the minimum quantity of Horne's dry basic lead acetate
and shake thoroughly. Filter.
Direct polarization.—Polarize the solution to obtain the direct reading and
correct first for zero point displacement and then correct to the value which would
have been obtained if 26 g of the sample were taken in 100 ml of solution, (P).
Invert polarization.—Pipette 75 ml of the clear filtrate into a 100-ml flask, add
10 ml of HCl (d 20°/4°, 1.1029). Immerse in a water bath which is maintained
at 70° C. Agitate continually for 3 minutes and allow to remain in the bath for a
total time of 10 minutes. Cool quickly and make up to volume at the tempera-
ture at which the observations are to be made. Shake and filter as rapidly as
possible. Polarize. Correct first for zero-point displacement, and then correct
to the value which would have been obtained if 26 g of the sample were taken in
100 ml of solution (P’).
1 See also p. 155.
Polarimetry, Saccharimetry, and the Sugars 797
All polarizations shall be made in water-jacketed tubes provided with tubulature
and thermometer.
Substitute these values of P and P' in the following equation:
_(.5142+.00196(1-20)) P— P.
*~ *.sińfooã300 fºo) (145)
Substitute the value of S and the value of P in eq. 146 and solve to find the
percentage of raffinose:
P– (1–.0003(t–20)) S
R =
1.852 (146)
R = 0.54(P— (1–.003 (t–20))S)
OT
Determination of reducing sugars in beet molasses.—The method for the determi-
nation of reducing sugars in beet molasses shall be as follows:
For the determination of reducing sugars in a molasses containing approximately
50 percent of total sugars, 20 g of the beet molasses are transferred to a 250-ml
flask, dissolved, clarified with the minimum quantity of normal lead acetate,
made to volume, and filtered. The clear filtrate is freed from the excess of lead
with dry potassium oxalate. Taking aliquot portions of 50 ml of the lead-free
filtrate, the reducing sugars are determined as described under “cane molasses.”
Find the amount of reducing sugars corresponding to the weight of copper obtained
from table 78, p. 564 (column marked “2 g total sugars”).
In the event that the percentage of total sugars in the beet molasses varies ap-
preciably from 50 percent, such a weight is taken that 50 ml of the solution will
contain 2 g of total sugars.
Determination of weight per gallon of molasses.49—A special 100-ml volumetric
flask with a neck of approximately 8-mm inside diameter shall be used. Weigh
the flask empty and then fill it with molasses, using a long-stemmed funnel
reaching below the graduation mark, until the level of the molasses is up to the
lower end of the neck of the flask. The flow of molasses may be stopped by
inserting a glass rod of suitable size into the funnel so as to close the stem Opening.
Remove the funnel carefully to prevent molasses coming in contact with the neck,
and weigh flask and molasses. Add water almost up to the graduation mark,
running the water down the side of the neck to prevent mixing with the molasses.
Allow to stand for several hours or overnight to permit the escape of bubbles. Place
the flask in a constant-temperature water bath, preferably at 20°C, for a sufficient
time for it to reach the temperature of the bath, then make to volume at that
temperature, with water. Weigh. Reduce the weight of the molasses to vacuo
and calculate the density. From table 117, page 644, convert to weight per
gallon in air.
Correction for temperature.—The temperature of the molasses shall be deter-
mined at the time of gauging. The weight per gallon of the molasses shall be
corrected to this temperature, using as the factor for the cubical expansion of
molasses 0.00043 per unit volume per degree centigrade. The weight per gallon
at the temperature of gauging is therefore
- W.
TTE0.0004:3(i, j’
W, (147)
where
t = temperature of determination,
tº = temperature of gauging,
W2=weight per gallon at temperature, t
Wi-weight per gallon at temperature, ty.
2
y
Moisture determination.—For the determination of moisture in sugars, dry
approximately 4 g in a metal dish of a diameter of 55 mm and a height of 15 mm.
Each sample shall be subjected to a temperature of 100° C for 2 hours, care being
exercised that the dishes are not in close proximity to the heaters.
49 An example of the calculation is given on page 252 of this Circular.
323414°—42 52
INDEX
Page
Abbe refractometer----------------------------- 255
Abridged spectrophotometry------------------- 311
Absorption cells------------- 307, 311, 317, 318, 321, 322
Absorption, moisture, raw Sugar---------------- 15
Absorptive index, Specific---------------------- 303
Acetal derivatives------------------------------ 482
Acetohalogen Sugars, see Halogeno acetyl sugars.
Acetone derivatives of Sugars------------------- 483
Acetyl groups, determination------------------- 494
and halogen, determination------------------- 497
removal, see Deacetylation-- - - - - - - - - - - - - - 493, 495
Acetylated Sugars, see Acetylation of Sugars, and
individual Sugars.
Acetylation of Sirups--------------------------- 463
Acetylation of Sugars--------------------------- 485
Catalysts for---------------------------------- 485
pyridine------------------------------------ 486
Sodium acetate----------------------------- 488
Sulfuric acid-------------------------------- 487
Zinc chloride-------------------------------- 489
conversion of halogeno acetyl to fully acety-
lated Sugars-------------------------------- 489
interconversion of alpha and beta fully acety-
lated Sugars---------------------------- 485, 489
preparation of partially acetylated sugars 486, 491, 521
Acids, preparation from Sugars, See Aidonic acids.
Activated carbon, see Decolorizing carbon.
Activation constant for mutarotation reaction- 447, 762
Adenosine, preparation------------------------- 477
Picrate--------------------------------------- 477
Adjustable Sensitivity Saccharimeters---------- 70, 72
Adsorption------------------------------------- 335
isotherm-------------------------------------- 336
Sugar by bone Char--------------------------- 126
Adulterated Sugar------------------------------ 791
Air thermostats, see Thermostats.
Alcohols, polyhydroxy-------------------------- 530
Aldehydo-d-glucose pentaacetate--------------- 490
preparation----------------------------------- 490
Aldehydo Sugars, derivatives--------------- 486, 490
preparation----------------------------------- 490
Aldonic acids----------------------------------- 521
equilibrium in Solutions------------------ 440, 521
general characteristics------------------------ 521
methods of preparation--------------------- 522
preparation by oxidation of Sugars-------- 523, 528
purification and Separation of----------------- 524
Aldoses, determination------------------------- 208
Hinton and Macara with Chloramine-T ------ 211
iodometric, Willstatter and Schudel---------- 210
iodometric, Kline and Acree------------------ 210
Alkali, action on lactose------------------------ 467
Allihn, method for dextrose----------------- 173,584
Allonic lactone, preparation--------------------- 527
d-Allonic lactone, reduction--------------------- 456
d-Allose and derivatives------------------------ 704
preparation----------------------------------- 456
l-Allose and derivatives------------------------ 705
Alpha and beta modifications of Sugars. ------- 416,
422,424, 435,439, 441,442, 448, 453,485
Altronic acid----------------------------------- 527
d-Altrose and derivatives----------------------- 706
l-Altrose and derivatives----------------------- 707
Alumina cream--------------------------------- 119
Amino Sugars, see Glucosamine; Chondrosamine.
Amplitudes, Variable nature in light------------ 2, 5
Amsterdam version of International Sugar
Analyzers, elliptic------------------------------ 30
Angles, small, measurement with Rochon prism- 33
Anhydro Sugars-------------------------------- 4
Aniline chloride test----------------------------
Babinski
Page
Aniline acetate test for furfural----------------- 242
Apparatus (see particular item).
Apparent purity-------------------------------- 406
table of factors-------------------------------- 702
Arabinose, determination as phenylhydrazone-- 219
l-Arabinose, and derivatives-------------------- 708
Imethyl pyranoside--------------------------- 514
preparation from mesquite gum--------------- 457
d-Arabonic acid, potassium Salt---------------- 528
Arago, rotation of plane of polarization-------- 34, 39
Arc, See Light Sources.
Arrhenius, formula for velocity constants. 133,443,447
Asbestos---------------------------------------. 324
filters----------------------------------------. 325
preparation------------------ - - - - - - - - - - - - - - - 325
Gooch Crucibles-------------------------- 179, 325
preparation as filter aid----------------------. 324
Ash determination methods-------------------. 263
Carbonation---------------------------------- 264
Conductance---------------------------------. 275
direct----------------------------------------- 264
for honey------------------------------------ 232
for raw and Soft Sugars-------------------- 263,277
for refinery Sirups---------------------------- 277
Zerban and Sattler--------------------------- 276
general conductance------------------------
Asymmetric carbon, definition-------.-----------
Atmospheric pressure, see Barometric pressure.
Atomic weights, table-------------------------- 703
Axes of eliptical oscillations, major and minor--- 9
Axis error, apparatus------------------------- 58, 59
of quartz control plate------------------------
and Ablamovitch modification of
Clerget method------------------------------- 162
Balances--------------------------------------- 112
analytical------------------------------------ 112
Sugar----------------------------------------- 112
weight per gallon----------------------------- 252
Balling, degrees--------------------------------- 248
Barfoed method for monoSeS-...------------------ 206
Monier-Williams modification.---------------- 207
Sichert and Bleyer modification - ---------- -- 206
Barium methylate, catalyst for deacetylation--- 459,
63,464,493
Barley Sugar tests, SampleS----------------- 371, 385
Barometric pressure, and boiling-point elevation- 368
and hydrogen electrode ----------------------- 286
Bartholinus, Erasmus, discovery of double re-
fraction------------------------------------- 33, 39
Basic lead acetate, see Lead acetate, basic.
abridged spectrophotometer-------- ---------- 312
improvements in Brace sensitive strip system- *
polariscope tube-----------------------------. 1
Saccharimeter------------------------------- 70, 72
Sugar balance--------------------------------- 112
Sugar flask------------------------------------ 108
Bates-Jackson version of the International Sugar
Scale----------------------------------------- 78
aumé----------------------------------------- 248
hydrometers---------------------------------- 248
Scales----------------------------------------- 248
Beams, ordinary and extraordinary------------- 22
Beet molasses, see also Molasses.
Clerget analysis, Osborn and Zisch----------- 160
raffinose determination----------- 143, 156, 159, 160
sucrose determination-------- 155, 156, 157, 159, 160
Beet sugar, see Sugar.
Benedict, micromethod for dextrose------------ 197
Benzoyl Sugars. ---------------- ---------------- 502
Benzoyl talose (mono), preparation------------- 479
800
Circular of the National Bureau of Standards
Page
4,6-Benzylidine-a-d-glucose, preparation - - - - - - - - 484
Benzylidine Sugars- - - - - - - - - - - - - - - - - - - ------ 483,484
Bertrand, method for reducing sugar - - - - - - - - - - - 174
Bichromate filter for Saccharimeter light Sources. 84
Bingham viscometer---------------- - - - - - - - - - - - 352
Biot, apparatus for studying optical rotation. 34,35,42
experiments on polarization----- - - - - - - - - - - - - - - 35
Biquartz of Soleil---- - - - - - - - - - - - - - - - - - - - - - - - - 39
Block comparator (pH) -- - - - - - - - - - - - - - - - - - - 297, 299
Boiling-point elevation - - - - - - - - - - - - - - - - - - - - - - - - - 367
atmospheric pressure - - - - - - - - - - - - - - - - - - - - - - - -. 368
effect of concentration of Solute - - - - - - - - - - - - - - - 366
derivation of table------ - - - - - - - - - - - - - - - - - - - - -. 365
equation for Sucrose Solutions - - - - - - - - - - - - - - - - 366
Vapor pressure lowering. - - - - - - - - - - - - - - - - - - - - 367
Boiling points------------------------------ 365, 366
definition----------------------------------- 3
Sucrose Solutions.-------------- - - - - - - - - - - - 365, 694
Bone char (bone black) --------------------- 126,338
decolorizing tests- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 338
Brace sensitive-strip polarizer. ... - - - - - - 41
Brace sensitive-strip system, perfected by Bates 46
Brewster:
filter for 560 mpi-- . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
and Phelps, method for preparing asbestos- - - 324
Bridge:
circuit for photoelectric measurements -- - - - - -. 320
electrical conductance - - - - - - - - - - - - - - - - - - - - - - 266
Brix---------------------------------------- 248, 332
by dilution ----------------------------------- 250
calculation on dilution-------------------- 250, 326
hydrometers---------------------------------- 2
tables-------------------------------- 614, 624, 626
Brodhun and Schönrock------------------------
Imeasurement of axis error---...- - - - - - - - - - - - - - - - - 58
planeness and parallelism of quartz plates - - - - 58
Bromides, double Salt of Calcium lactobionate
and calcium bromide------------------------- 525
Bromine oxidation of Sugars - - - - - - - - - - - - - - - - - - - - 523
Bromo-acetyl sugars, see Halogeno acetyl Sugars.
Bromo-tetraacetyl-o-d-glucose, preparation ----- 500
Bromo-tetraacetyl-o-d-talose, preparation - - - - - - - 500
Browne, modification of Clerget method . . . . . . . . 128
polarizing constants. - - - - - - - - - - - - - - - - - - - - - - 226
Brown, Morris, and Millar, method for reducing
Sugar in molasses- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 177
Buffer action----------------------------------- 280
Buffers, standard-----------------...- - - - - - - - - - - - - 295
mixtures-------------------------------------. 295
Stock Solutions. ------------------------------- 294
Burners---------------------------------------- 378
gas, Constant pressure - - - - - - - - - - - ------------- 376
nozzles for---------------------------------- 378
Special star, for candy tests - - - - - - - - - - - - - - - - - - - 378
Cadmium-gallium lamp, Bates type - - - - - - - - - - - - 54
Cadmium-gallium alloy, properties- - - - - - - - - - - - - 54
Cadmium lines.-------------------------------- 55
as light Sources----------------------------- 52, 54
Cadmium-silver arc, rotating------------------- 54
Cadmium Spectra- - - - - ------------------------- 55
Calcium altronate, preparation-- - - - - - - - - - - - - - - - 527
Calcium bromide-calcium lactobionate, prepara-
tion------------------------------------------ 525
Calcium chloride compounds of d-gulose. 453, 465, 515
Calcium chloride compounds of sugars, for puri-
fication of glycosides.----- - - - - - - - - - - - - - - - - 513, 515
Calcium gluconate, preparation - - - - -.-- - - - - - - - - - 524
Calcium lactobionate-calcium bromide, prepa-
ration---------------------------------------- 525
Calibration------------------------------------- 553
volumetric flasks - - - - - - - - - - - - - - - -------------- 558
Saccharimeter, basis - - - - - - - - - - - - - - - - - - - - - - - - - - 73
Calomel, pure, preparation . . . . . . . . . ------------ 284
Calorific value of Sucrose - - - - - - - - - - - - - - - - - - - - - - 551
Canadian lead number- - - - - - - - - - - - - - - - - - - - - - - - - 237
Candy in Solution - - - - - - - - - - - - - - - - - - - - -, * - - - - - - - - 374
analysis-------------------------------------- 374
Color measurement - - - - - - - - - ------------------ 374
examination---------------------------------- 374
Candy, Solid, examination---------------------- 374
Color measurement--------------------------- 374
Candy test------------------------------------- 370
alteration of practice----------- - - - - - - - - - - - 385, 388
analysis of product --------------------------- 378
boiling-Vessels---------------------------- 371, 375
cooling Slabs---------------------------------- 383
crystallization during------------------------- 371
Candy test—Continued. Page
equipment----------------------------------- 375
“foam number” ------------- - - - - - - - - - ---...--- 373
for indicating quality of sugar - - - - - - - - - - - - - - - - 386
“frothing”------------------------------------ 386
heat cycle.------------------------------------ 384
heating devices--------------- - - - - - - - - - - - - - - - - 376
“overweight”------------------- - - - - - - - - - - - - - - 374
polarimetric methods--------------------- 371, 388
procedure-------------------------------- 370, 372
procedure, improvements of National Bureau
of Standards over Hooker method - - - - - - - - - - 385
Dllre StlcroSe- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 385
quenching plates----------------------------- 384
reference Samples.------------ - - - - - - - - - - - - - - - - 385
relation to impurities in sugar- - - - - - - - - - - - - - - - 387
reliability----------------------------------- 386
Sampling------------------------------------- 385
Saturation-point.------------------------...----- 384
Star burners, Special - - - - - - - - - - - - - - - - - - - - - - - - - - 378
Stability of Sugar-- - - - - - - - - - - - - - - - - - - - - - - - - - - - 387
Stoves---------------------------------------- 381
“strength” of sugars-------- - - - - - - - - - - - - - - - - - - 388
utility---------------------------------------- 387
water, quantity for:
Hooker method, volume . . . . . . . . . . . . . . . . 370, 385
National Bureau of Standards Inethod,
Weight-------------------------------- 372, 385
Water-retention----------- - - - - - - - - - - - - - - - - - - - - 374
“weak” sugars.------------------------------- 388
weight of sample:
ooker--------------------------------- 370, 385
National Bureau of Standards - - - - - - - - - - 372, 385
Value to producer------------ - - - - - - - - - - - - - - - - _ 387
Value to Consumer---------------------------- 387
Variation, instrumental ----------------, - - - - - - 389
yield----------------------------------------- 374
Cane sugar, see Sugar.
Capillary tube viscometers- - - - - - - - - - - - - - - - - - - - - 352
Bingham------------------------------------- 352
Ostwald-------------------------------------- 352
Ubbelohde. ---------------------- - - - - - - - - - - - - 353
Carbon, see Decolorizing carbon.
Caramelization in candy tests-- - - - - - - - - - - - - - - - - 387
Carbohydrates, see also Sugars.
classification---------, -- - - - - - - - - - - - - - 411, 414, 424
Carbonated ash method. --------. . . . . . . . . . . . . . . 264
Carbonate derivatives of sugars. -- - - - - - - - - - - - - - 503
removal of carbonate groups -- - - - - - - - - - - - - - - - - 504
Carbon chain of Sugars.
lengthening----------------------------------- 527
Shortening-------------------------------- 469, 528
Carbonyl chloride reaction products with sugars- 504
Cell constant, conductivity--------------------- 272
definition------------------------------------- 272
temperature conversion--------- - - - -, - - - - - - - - - 273
Cellobiose:
derivatives----------------------------------- 710
Octaacetate, preparation-- - - - - - - - - - - - - - - - - - - - 459
preparation----------------------------------- 459
Cells:
Conductivity--------------------------------- 268
determination Of Constant - - - - - - - - - - - - - - 239, 272
testing--------------------------------- 239, 274
photoelectric--------------------- 316, 317, 318, 320
Celtrobiose, and derivatives-------------------- 711
Centrifuge-------------------------------------- 394
Certification of quartz control plates - - - - - - - - - - 62, 91
Chloro-acetyl sugars, see Halogeno acetyl sugars.
Chloro-heptaacetyl-neolactose, preparation----- 502
Chloro-tetraacetyl-o'-d-glucose, preparation - - - - - 499
Chloro-tetraacetyl-o-d-mannose, preparation---- 499
Chondrosamine, acetyl derivatives - - - - - - - - - - - - - 712
Circular degrees, measurement of rotation in - - - 33
Circular Oscillations--------- - - - - - - - - - - - - - - - - - - - 11
Circularly polarized components and photo-
gyric effects----------------------------------
Circular-scale polariscopes, test -- - - - - - - - - - - - - - - - 46
Cis and trans configuration, relation to chemical
properties------------------------------------ 436
Clarification for Color measurement - - - - - - - - - 326, 327
Clarification (raw Sugars)----------------------- 119
alumina Cream ------------------------------- 119
basic lead acetate----------------------------- 120
basic lead nitrate--------------------. --- - - - - 124
bonechar------------------------------------- 126
Horne method-------------------------------- 123
hydrosulfite---------------------------------- 125
hypochlorite---------------------------------- 125
Polarimetry, Saccharimetry, and the Sugars
Clarification (raw sugars)—Continued. Page
Clerget analysis, beet molasses, Osborn and l
ZiSch -
Clerget divisor--------------------------------- 127
basic values-------------------------- 127, 152, 153
definition------------------------------------- 127
effect of hydrochloric acid - - - - ---------------- 136
influence of sugar concentration--------------- 133
influence of temperature. --------------------- 134
Clerget formula-------------------------------- 127
evaluation of “m’’---------------------------- 138
Clerget method--------------------------------- 126
Compensation-------------------------------- 140
detailed procedure --------------------------- 152
effect of reagents on invert rotation----------- 137
effect of reagents on sucrose rotation-----. . . . . 139
inversion--------------------------------- 153, 158
acid---------------------------------------- 127
enzyme--- - - - - - - - - - - - - - - - - - - - - - - - - - - - ------- 146
Clerget method modifications:
Babinski and Ablamovitch------------------- 162
Browne--------------------------------* -- - - - - - 128
Herzfeld.------------------------------------- 128
Schlemmer----------------------------------- 163
Schreſeld------------------------------------- 129
Stanek--------------------------------------- 162
Steuerwald----------------------------------- 163
Coefficient, expansion, of molasses. -- - - - - - - - - - - - 797
temperature, of rotation of quartz, 86e also
Temperature coefficient------------------- 60, 92
Coherent light beams--------------------------- 7
Color dilution---------------------------------- 329
Volume basis--------------------- - - - - - - - - - - - - 329
weight basis---------------------------------- 330
Solid Sugar------------------------------------ 331
Color filters:
HeSS-Ives------------------------------------- 311
Keane and Brice----------------------------- 323
Zeiss-Pulfrich-...------------------------------ 316
Colorimetric methods for reducing Sugars -- - - - - - 199
Color index, Keane and Brice - - - - - - - - - - - - - - - - - - 323
Color measurement, in solid and dissolved
Candies--------------------------------------- 374
Color, nomenclature--------- - - - - - - - - - - - - - - - - - - - 301
for Sugar-------------------------------------- 302
Colorimeter, Duboscq, Stammer---------------- 312
Colorimetric pH, procedure - - - - - - - - - - - - - - - - 296, 298
Colorimetry---------------------------------- _ _ 300
Color standards (for Sugar)-------- - - - - - - - - - - - - - 334
UlDCD------------------------ - - - - - - - - - - - - - - - - 334
Spengler and Von Heyden.------ - - - - - - - - - - - - - - 334
ills----------------------------- - - - - - - - - - - - - 334
Comparator, block- - - - - - - - - - - - - - - - - - - - - - - - - 297, 299
Compensating photoelectric circuits - - - - - - - - 320, 323
Compensator, quartz wedge of Soleil------- 37, 39, 64
Compensators (elliptic) ------------------------- 31
Babinet-------------------------------------- 31
Brace----------------------------------------- 31
Concentration of Solute------------------------- 366
boiling-point elevation------------------------ 366
Va))0ſ DTCSSUlle - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 367
Concentration, sugar Solutions for colorimetry - - 326
Condensed milk, analysis.---------- - - - - - - - - - - - 205
levulose by Monier-Williams Method ... - - - - - - 207
levulose by Hinton and Macara method. - - - - - 205
Conductance (electrical)---------...-------------- 265
bridge---------------------------------------- 266
equation for equivalent----------------------- 272
extrapolating to infinite frequency--- - - - - - - - - - 268
maple products------------------------------- 238
measurement, frequency of a. C- - - - - - - - - - - - - - - 268
null-point indicator. -------------------------- 267
oscillator for measurement - - - - - - - - - - - - - - - - - - - 268
potassium chloride Solutions------------------ 272
potassium chloride Solutions, table. ----------- 272
Specific--------------------------------------- 265
equations---------------------------------- 268
temperature coefficient - - - - - - - - - - - - ----------- 270
Conductivity cell constant - - - - - - - - - - - - --------- 272
definition------------------------------------- 272
determination-------------------------------- 272
temperature conversion----------- - - - - - - - - - - - - 273
Conductivity Cell------------------------------- 268
platinizing electrodes------------------------- 270
testing of------------------------------------- 274
Configuration and chemical properties---------- 435
Configurational types, pyranoses- - - - - - - - - - - - - - - 426
Configuration of alpha and beta sugars. - - - 422, 425
Constant temperature rooms - - - - - - ------------- 97
Page
Constants of quartz wedge saccharimeter . . . . . 73, 80
Control plates, see Quartz control plates.
Conversion factors:
Amsterdam ---------------------------------- 79
Bates-Jackson -- - - - - - - - - - - - - - - - - - - - - - --------- 78
French--------------------------------------- 75
Herzfeld-Schönrock - - - - - - - - - - - - - - - - - - - - - - - - - - 78
entºke-------------------------------------- 77
Scale comparison factors - - - - - - - - - - - - - - - - - - - - - - 84
Copper determination-------------------------- 178
colorimetric---------------------------------- 199
dichromate----------------------------------- 183
electrolytic----------------------------------- 180
electrometric. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 183
gravimetric----------------------------------. 178
iodometric------------------------------------ 180
permanganate------ - - - - - - - - - - - - - - - - - - - - - - - - - - 182
Copper reduction methods for sugar analysis:
clarification of crude products for - - - - - - - - - - - 169
microchemical-------------------------------- 196
Selective-------------------------------------- 203
Volumetric----------------------------------- 185
Copper tartrate complexes -- - - - - - - - - - - - - - - - - - - - 166
Corn cobs, preparation of d-xylose. - - - - - - - - - - - - - 481
Cornu, improved Jellet prism . . . . -- - - - - - - - - . . . . 37
Cººtion, Saccharimetric, for tropical coun-
Ties- - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - -, . -
Correction, Saccharimetric, to the International
Sugar Scale------------------------------- . . . . 0
Cover-glass error, reflectometry----- - - - - - - - - - - - 307
Cover glasses-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 106,307
“C-ratio,” conductance method for ash determi-
nation --------------------------------------- 275
Creydt raffinose formula----------- - - - - - - - - - - - - - 143
Crucibles, Gooch, preparation------------ - - 179, 325
Crystallization------------------------- 390, 394,441
levulose-------------------------------------- 404
reducing Sugars------------------------------- 441
Crystallizer------------------------------------ 394
Crystallography-------------------------------- 533
dextrose hydrate.----------------------------- 540
SuCTOSe--------------------------------------- 534
SugarS---------------------------------------- 533
Crystals---------------------------------------- 13
uniaxial-------------------------------------- 14
biaxial---------------------------------------- 15
Cuprous oxide reduction------------------------ 179
With hydrogen-------------------------------- 179
With alcohol . . . . . . .----------------------- 179,796
Customs Regulations--------------------------- 781
Cyanhydrin Synthesis---------------------- 524, 527
d- and l-classification---------------. ------------ 424
Deacetylation of acetylated SugarS. - - - - - - - - - - - - - 493
cellobiose octaacetate. -----------. ------------ 459
gentiobiose octaacetate------------------------ 463
4-3-glucosido-d-mannose octaacetate. - - - - - - - - 464
methyl hexaacetyl-4-3-glucosido-d-mannoside. 493
neolactose heptaacetate----------------------- 74
Dentaacetyl-Salicin---------------------------- 494
Deacetylation Inethods------------------------- 493
alkali----------------------------------------- 494
barium methylate---------------------------- 493
Sodium methylate. --- - - - - - - - - - - - - - - - - - - - - - - - 494
Decolorization tests, carbon - - - ----------------- 334
With raw Sugar----...-------------------------- 335
With molasses-------------------------------- 336
procedure-------...----------------------- 335, 336
nomograph for calculation-------...------------ 339
Decolorizing Carbons- - - - - - - - - - - - - - - - - - - -------- 334
evaluation------------------------------------ 334
moisture determination. . . . . -- - - - - - - - - - - - - - - - - 334
Decolorizing efficiency, carbon--------- - - - - - - - - - 334
Decolorizing isotherm- - - - -------------- 334, 337, 338
Density---------------------------------------- 247
Density determination . . . ...-------------------- 249
by direct reading balance------------------. -- 252
by hydrometer------------------------------- 249
by picnometer-------------------------------- 250
Density of solutions -. -...------------- - * * *- - - - - sº * = sm 247
dextrose-------------------------------------- 652
levulose-------------------------------------- 650
SUCTOS8-- - - - - - - - - - - - - - - - - - - --------------- 253, 626
Desiccating caps, Wiley - - - - - - - - - - - - - - - - - - - - - - - - 105
2-Desoxy-galactose, preparation. --- - - - - - - - - - - - - - 460
DeSoxy Sugars---------------------------------- 712
Detritylation. . . . -------------------------- - - - - 512
Dextrin, in honey - - - - - - - - - - - - - - - -----------...- 234
802
Circular of the National Bureau of Standards
IPage
Dextrin, Steinhoff method--...----------_________ 230
Dextrose, see also d-Glucose:
(anhydrous) stability------------------------- 360
density of Solutions.------------ - - - - - - - - - - - - -. 652
derivatives, see d-Glucose.
determination:
in honey------------------------------------ 233
Steinhoff method --------------------------- 230
determination (micro)------...----------------- 196
Benedict method.-------------------------- 197
ferricyanide, Hagedorn and Jensen method - 198
Somogyi method. ----------------------- . . . 196
levulose and, in mixtures, determination. 203, 223
maltose, dextrins and, Steinhoff method. - - - - - 230
monohydrate, crystallography---------------. 540
Stability------------------------------------ 359
normal weight----------------------------- 82, 562
purification----------------------------------- 390
solubility:
in levulose Solutions - - - - - - - - - - - - - - - - - - - - - - - - 362
in Water-----------------------------------. 359
Specific rotation - - - - - - - - - - - - - - ------------- 83, 562
Standard Sample.----------------------------. 551
structural formula------------------------ 411, 414
Structure--------------------------------- 411, 414
Diacetone-d-fructose, preparation - - - - - - - - - - - - - - 483
Diacetone-d-glucose----------------------------. 4
hydrolysis-------------------------------- 483,484
preparation----------------------------------. 4
Diacetone-o-methyl-d-mannopyranoside, prepa-
ration---------------------------------------- 48
Dial decade--------------------------------- - - - 321
Diastase in honey-----------------------------. 235
Diastereoisomers - - - - - - - - - - - - ------------------. 419
Diatomaceous earth ---------------------------- 327
purification----------------------------------- 328
Honig-------------------------------------- 329
Zerban and Sattler - - - ---------------------- 328
Sirup filtration-------------------------------- 328
Dibasic acids of Sugars. ---------...--------------- 528
Dichromate method for copper----------------- 183
colorimetric----------------------------------- 184
electrometric--------------------------------. 183
Diffusing Sphere------------------------ 307, 309, 310
Difructose anhydrides and derivatives---------- l
Dimethyl sulfate:
for methylating Sugars.------------------- 506, 507
for preparation of glycosides ------------------ 518
Dipping refractometer-------------------------- 259
Direct polarization ----------------------------- 116
DiSpersion, rotatory:
of plane of polarization---------------------- 40, 64
Quartz---------------------------------------- 8
SuðFOS8--------------------------------------- 81
tals-----------------------------------------
by Crystals of quartz.------------------------ 13
discovery----------------------------------- 33, 39
in cover glasses------------------------------- 106
Drop-ratio for colorimetric pH------------------ 298
Dry Substance, in Sugars----------------------- 261
in molasses----------------------------------- 262
Duboscq colorimeter--------------------------- 312
Dry basic lead acetate-------------------------- 120
Dutch Color Standards-------------------------- 334
Ebert, Structure of Sodium lines----------------- 48
Pºal conductance, see Conductance, elec-
trica].
Electric lamps, see Light sources.
Electrodes:
antimony------------------------------------- 293
Calomel--------------------------------------- 282
Vessels-------------------------------------- 283
emf Values---------------------------------- 284
conductivity cell, platinizing--------------. -- 270
glass.-------------------------------------- -- 289
hydrogen--------------------------------- 285,288
gold-plated.--------------------------------- 289
Palladium---------------------------------- 288
platinum----------------------------------- 288
platinizing-------------------------------- 288
Poisoning----------------------------------- 288
polarization reactance-------------------- 268,274
quinhydrone.--------------------------------- 289
Calculation of pH--------------------------- 289
Silver-silver chloride-------------------------- 292
Electrodes—Continued.
Standard potential--------------------------
Electrolytic deposition of copper---------------- 180
Electrolytic oxidation of sugars--- - - - - - - - - - - 523, 524
Electrolytic reduction of sugars--- - - - - - - - - - - - - - - 5
Electrometric ash:
maple products------------------------------- 238
SūCTOS8--------------------------------------- 275
Electrometric method for reducing sugars------- 201
Elliptical oscillations------------------------- 2
Elliptically polarized light---------------------- 8
formulas-------------------------------------- 10
nature---------------------------------------- 9
production------------------------- - - - - - - - - - - 27
by doubly refracting plates----------------- 27
in electric and magnetic fields-------------- 29
by reflection-------------------------------- 20
Enantiomorphs, characteristics----------------- 418
Enzymes:
for purification of glycosides. - - - - - - - - - - - - - - - - - 513
hydrolysis of methyl glycosides-- - - - - - - - - - 423, 513
invertase------------------------------------- 146
melibiase------------------------------------- 147
Epimeric difference---------------------. - - - - 430
Epimerization:
With glycals------------------------------ 479, 531
With hydrogen fluoride- - - - - - - - - - - - - - - - - - - - - - - 501
With pyridine----------------, - . -- - - - - - - - 528
Equilibrium water:
Candy tests------------------------------- 372, 374
definition------------------------------------- 271
preparation----------------------------------- 271
Equipment, see particular item:
polariscopic at the National Bureau of Stand-
ards---------------------------------------- 46
Equivalent conductance, equation.------------- 272
Ethyl d-galactofuranosides---------------------- 517
Ethyl 3-d-glucofuranoside, preparation- - - - - - - - - 504
Evaporation, effect on polarization- - - ---------- 117
Evaporator------------------------------------- 393
Exchange Samples of raw sugar----------------- 790
Expansion, coefficient, molasses---------------- 797
Extraordinary and ordinary beams------------. 22
Factor, conversion, Bates and Jackson.-------- 78, 79
Factor, conversion, rotational ----------------- 0, 84
Falling-ball viscometers, Hoeppler.------------. 354
Fee Schedules----------------------------------. 553
Fehling Solution---------------------------- 168, 170
Filter aids-------------------------------------- 324
Filter apparatus:
Peters and Phelps---------------------------- 326
Zerban and Sattler--------------------------- 328
Filter (light)----------------------------------. 84
bichromate, influence on Saccharimeter read-
ing----------------------------------------- 87
bichromate, Saccharimetric - - - - - - - - - - - - - - 84, 87,89
Filter, spectral:
Brewster------------------------------------- 314
Gibson--------------------------------------. 314
IIlêICUTy alſo - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -. 324
dyed gelatin-------------------------------. 324
glass---------------------------------------. 324
Specifications------------------------------. 324
for 560 mpi-----------------------------------. 314
for 460 mu-----------------------------------. 314
Filtration:
Sugar Solutions--------------------------- 324, 326
With asbestos--------------------------------. 326
with diatomaceous earth---------------------. 327
Flame, Sodium light Source--------------------. 47
Flasks, Volumetric-----------------------------. 106
Flaws, quartz control plates, testing for --------. 57
Fluoro-acetyl Sugars, see Halogeno acetyl sugars-
Fluoro-tetraacetyl-o'-d-glucose, preparation------ 498
Formulas, structural: -
pentOSes, hexoses, heptoses, and ketoses------. 426
Fischer projectional - - - - - - - - - - - - - - - - - - 420,422,426
Haworth hexagonal----------------------- 416, 422
French Sugar Scale----------------------------- *
Frequency of alternating current for conduct-
ance measurements.--------------------------. 268
Fric Saccharimeter --------------------- 65, 68, 69, 70
d-Fructose, See also Levulose-------------------- 398
and derivatives------------------------------- 714
crystallization, from alcohol------------------ 404
from Water--------------------------------- 405
crystallography------------------------------- 543
Polarimetry, Saccharimetry, and the Sugars
d-Fructose—Continued. Page
density of Solutions--------------------------- 650
determination.
Jackson and Mathews modification of Nyns
method----------------------------------- 20:
dextrose and, analysis of mixtures - - - - - - - - 205, 223
diacetone------------------------------------- 483
difructose anhydrides and derivatives - - - - - - - - 713
effect of lead acetate-------------------------- 124
3-methyl-diacetone --------------------------- 508
methyl tetraacetyl-fructoside - - - - - - - --------- 519
mutarotation--------------------------------- 440
normal Weight-------------------------------- 766
pentaacetyl-keto------------------------------ 491
pentaacetyl, preparation---------------------- 487
precipitation of Calcium levulate--- - - - - - - - - - - - 400
preparation----------------------------------- 399
refractive index of Solutions--- - - - - - - - - - - - - - - - - 670
solubility in water------------ - - - - - - - - - - - - - - - - 360
Structural formula- - - - - - - - - - - - - - - - 413, 414, 416, 427
Structure---------------------------------- 413, 416
tetraacetate, preparation----- - - - - - - - - -* * - - - * * * * 492
l-Fucose, and derivatives - - - - - - - - - - - - ----------- 716
preparation from Seaweed. ---- - - - - - - - - - - -----. 460
phenylhydrazone, preparation. --------------. 461
Furanoses, structural formula- - - --------------. 414
Furanosides-----------------------------------. 415
methyl ox-d-arabinofuranoside... -------------- 514
preparation from carbonates. ------------- 504, 520
preparation from Sugar mercaptals------- ----. 517
Furfural---------------------------------------- 241
aniline acetate test - - - - - - - - - - - - - -------------- 242
estimation with phloroglucin. ---------------- 243
Gaertner polarizing spectrophotometer--------- 307
Galactal:
conversion to desoxygalactose----------------- 460
oxidation to d-talose-------------------------- 479
preparation----------------------------------- 532
d-Galactose:
and derivatives------------------------------- 717
ethyl furanoside------------------------------ 517
estimation and test----------------------- 218, 528
ethyl mercaptal, preparation - - - -------------- 521
methyl tetramethyl galactoside - - - - - - - - - - - - - - - 506
8-pentaacetate, preparation------------------- 488
preparation from lactose---------------------- 462
separation from d-talose----------------------- 479
Gallium-cadmium lamp, Bates type-...-------- 54, 55
Gallium, properties of -------------------------- 54
d-o-Galaheptose, and derivatives---------------- 720
d-8-Galaheptose, and derivatives---------------- 721
Galvanometer, multiflex------------------------ 319
Leeds & Northrup, type R------------------- 321
Gentiobiose, and derivatives-------- - - - - - - - - - - - - 722
octaacetate, preparation---------------------- 463
octaacetate, deacetylation - - - ----------------- 463
preparation from “Hydrol” --- - - - - - - - - - - - - - - -. 463
German (Ventzke) Saccharimetric scale --------- 77
Gillespie, Color Standards--- - - - - - - - - - - - - - - - - - - - - 298
method for pH------------------------------- 297
method, test procedure----------------------- 298
Glucal------------------------------------------ 531
d-o-Glucoheptitol, preparation ------------------ 530
d-or-Glucoheptose, and derivatives-------------- 724
d-6-Glucoheptose, and derivatives. -- - - - - - - - - - - - 725
d-Glucomethylose, and derivatives-- - - - - - - - - - - - 726
Glucosamine, acetyl derivatives. - - - - - - - - - - - - - - - 727
d-Glucose, See also DextroSe:
and derivatives------------------------------- 728
(anhydrous), Stability------------------------ 359
benzylidine derivatives. -- - - - - - - - - - - - - - - - - ---- 484
o:-bromo-tetraacetyl--------------------------- 500
o'-chloro-tetraacetyl--------------------------- 499
crystallography (monohydrate).--------------- 546
density of Solutions.-------------------------- 652
determination, See also Reducing Sugars.
in honey------------------------------------ 233
Steinhoff method. --- - - - - - - - - - - - - - - - -------- 230
determination, micro-methods:
Benedict method-- - - - - - - - - - - - - - - - - - - - - - - 197
Hagedorn and Jensen ferricyanide method. 198
Somogyi method ------------------------- 196
diacetone------------------------------------- 483
ethyl 3-d-furanoside--------------------------- 504
d-Glucose—Continued. Page
o'-fluoro-tetraacetyl--------------------------- 498
methyl glucosides ------------------------ 516, 518
methyl tetramethyl glucoside--------- - - - - - - - - 509
o:-methyl tribenzoyl-glucoside---------- - - - - - - - 512
o'-methyl 6-trityl glucoside-------------------- 512
Inonoacetone----------------------------- 483,484
monoacetone monocarbonate - - - - ------------- 504
(monohydrate), crystallography-------------- 540
(monohydrate), Stability - - - - ----------------- 359
normal weight-------------------------------- 562
pentaacetyl-aldehydo------------------------- 490
pentabenzoates------------------------------- 503
phenyl tetraacetyl-glucosides - - - - - - - - - - - - - - - - - 517
purification----------------------------------- 390
reducing power------------------------------- 191
Solubility:
in levulose Solutions------------------------ 361
in Water------------------------------------ 359
Specific rotation---------------------------- 83, 562
Stability-------------------------------------- 359
Standard Sample. ----------------------------- 551
structural formula------------ 411, 414, 416, 422, 426
Structure--------------------------------- , 415
tetraacetyl methyl glucoside - - - - - - - - - - - - - - - - - 516
Glucosides, see Glycosides, Glucose; Mothyl;
Ethyl; Phenyl; etc.
4-8-Glucosido-d-mannose, and derivatives------- 734
fluoro-heptaacetyl derivative from Octaacetyl-
cellobiose----------------------------------- 501
hexaacetyl------------------------------------ 492
hexaacetyl derivative of the methyl Orthoace-
tate----------------------------------------- 492
iodo-heptaacetyl------------------------------ 501
preparation----------------------------------- 464
Glycals----------------------------------------- 531
Glycosides---------------------- 415, 417, 423, 433, 513
Oxidation by periodic acid -------------------- 423
preparation by Fischer method.--------------- 513
preparation by Koenigs-Knorr reaction- - - - - - - 516
preparation from halogeno-acetyl Sugars------ 516
preparation from Sugar mercaptals------------ 517
preparation with dimethyl sulfate - - - - - - - - - - - - 518
preparation with methyl iodide--------------- 519
purification------------------------------- 513, 515
Separation of isomers. . ------------------- 513, 515
structural determination-------------------- . . 423
Gooch crucibles, preparation---------------- 179, 325
Granulated Sugar, see Sugar, granulated.
Grape sugar, see Dextrose.
Gravimetric methods for reducing Sugars. ------ 170
d-or-Guloheptose, and derivatives--------------- 735
d-8-Guloheptose, and derivatives - - - - - - - -------- 735
d-Gulonic lactone, reduction.------------------- 465
d-Gulose, and derivatives--- - - - - - - - - - - - - - - ------ 736
calcium chloride compounds of methyl gulo-
Sides----------------------------------- 513, 515
effect of calcium chloride on equilibrium ------ 453
methyl gulosides------------------------------ 515
preparation of calcium chloride compound---- 465
Guanosine-------------------------------------- 477
preparation and purification------------------ 477
hydrolysis to d-ribose. ------------------------ 477
Gumlich, measurement of axis error------------ 58
Hagedorn and Jensen, micromethod for reducing
SugarS.---------------------------------------- 98
Haidinger rings for testing quartz plates-------- 58
Half-cells, see also Electrodes.
Calomel--------------------------------------- 282
preparation--------------------------------. 284
Half-shade, angle----------------------------- 37, 70
elliptic--------------------------------------- 30
polariscope, Jellet--------------------- ... * ~ * * * * 37
prism and polariscopes:
Jellet-Cornu ------------------------------- 37
simplified, Schmidt and Haensch--------- 37
Lippich---------------------------------- 40, 43
Saccharimeters------------------------------ 64, 70
Systems, Jellet-------------------------------- 37
Laurent---------------------------------- 37, 41
Lippich---------------------------------- 40, 41
Halogeno-acetyl sugars - - - - - - - - - - .-- - - - - - - - - - - - - - 498
conversion to acetylated glycosides - - - - - - - 486, 516
conversion to methyl orthoacetyl derivative- 486, 492
804
Circular of the National Bureau of Standards
Halogeno-acetyl sugars—Continued. Page
conversion to other sugars during preparation 498,
501, 502
conversion to partially acetylated sugars 486, 491
determination of halogen and acetyl groups - - 497
conversion to fully acetylated sugars. . . . . . 489
discussion of reactions, preparation, and prop-
erties---------------------------------- 498, 516
reactions-----------------------------------. 516
Heat of activation, mutarotation reactions-- 448, 762
Heat of combustion of sucrose - - - - - - - - - - - - - - - - - - 551
Helium light ---------. ------------- . . . . . . . . . . . . .306
Heptaacetyl-4-3-glucosido-d-mannose, prepara-
tion-----------------------------------------. 91
Heptamethyl sucrose, preparation - - - - - - - - - - - - - 507
Heraeus lamp - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 51, 53
Herles Solution --- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 124
Herzfeld method, for invert sugar--- - - - - - - - - - - - - 174
for preparation of pure Sucrose -- - - - - - - - - - - - - - - 392
for invert Sugar determination --- - - - - - - - - - - - - 174
modification of Clerget method_ _ _ _ _ _ _ _ - - - - - - - 128
Herzfeld-Schönrock, conversion factor - - - - - - - - - - 7
Herzfeld-Schonrock, version of International
Sugar Scale----------------------------- - - -- - - - 78
Hexaacetyl-4-6-d-glucosido-d-mannose:
1,2 methyl orthoacetate, preparation -- - - - - - - - - 492
preparation from Ortho-ester -- - - - - - - - - - - - - - - - - 492
Hexaacetyl-o'-d-o-mannoheptose, preparation
from 8-isomer... -------------- - - - - - - - - - - - - - - -
High-temperature polarization---- . . . . . . . . -- 232, 233
apparatus------------------------------------ 233
tube------------------------------------------ 1
Hinton and Macara, Chloramine-T method for
aldoses- - - - - - - - - - - - - - - - - - * ~ * ~ * * *- - - - - - - ** - * * 211
method for levulose in condensed milk. -- - - - - - 205
Hoeppler viscometer---------------------------- 354
Homogeneity of quartz control plates--------- 57.61
Honey------------------------------------------ 232
analysis-------------------------------------- 232
determination of destrose and levulose. - - - 211, 233
dextrose and levulose content--- - - - - - - - - - - - - - 363
preparation of melezitose from - - - - - - - - - - - - - - - - 472
Honig, purification of kieselguhr---------------- 329
Hooker Candy test-------------------------- 370, 388
boiling vessels-------------------------------- 371
Copper Casserole------------------------------ 371
weight of Sample. ------------------------ 370, 385
Horne method for correction for volume of
precipitate-----------------------------------. 122
Horne method for clarification - - - - - - - - - - - - - - - - - 123
Hudson isorotation rules------------ - - - - - - - - - - - - 432
Hudson lactone rule- - - - - - - - - - - - - - - - - - - - - - - - - - - - 434
Huygens discovery of polarized light----- - - - - - - - 33
Hydrazones. - - - - - - - - - - - - - - - - - - - - - - - - - - - 218, 219, 461
conversion of fucose phenylhydrazone to
fucose-------------------------------------- 461
preparation of l-fucose phenylhydrazone -- - - - - 461
Hydrogenation of Sugars--------- - - - - - - - - - - - - - - - 530
Hydrogen electrode, Clark---------------------- 287
Simple forms---------------------------------. 288
Hydrogen fluoride, anhydrous, preparation and
USe- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 499
epimerization of acetylated sugars - - - - - - - - - - - - 501
Hydrogen-ion concentration, see also pH - - - - - - - 279
definition---------------------------- - - - - - - - - - 279
exponent------------------------------------- 279
measurement--------------------------------- 27
Hydrol, preparation of gentiobiose from - - - - - - 463
Hydrolysis of acetyl groups, see Deacetylation.
Hydrolysis of carbonate groups. - - - - - - - - - - - - - - - - 504
Hydrolysis of sugar in Candy tests - - - - - - - - - - - - - - 387
Hydrolysis of trityl groups. - - - - - - - - - - - - - - - - - - - - 512
Hydrometers------------------------------- 248,249
Hydrosulfite------------------------------------ 125
Hypochlorite----------------------------------- 125
Ice baths for testing thermometers.-- - - - - - - - - - - - 110
Incoherent light beams - - - - - - - - - - - - - - - - - - - - - - - - - 5
d-Idose, and derivatives. - - - - - - - - - - - - - - - - - - - - - - - 737
Immersion refractometer - - - - - - - - - - - - - - - - - - - - - - - 259
Index, see Refractive; Color; Absorptive: etc.
Indicator solutions, pH, Clark and Lubs. - - - - - - 296
Inhomogeneity of light - - - - - - - - - - - - - - - - - - - - - - - -
International Commission for Uniform Methods
of Sugar Analysis.-------------------------- 767
method for preparation of Sucrose.-- - - - - - - - - - - - 392
refractive index Scale- - - - - - - - - - - - - - - - - - - - - - - - - 255
resolution on Colorimetry - - - - - - - - - - - - - - - - - - - - - 301
résumé of work------------------------------- 767
Sugar Scale------------------------------------ 77
Page
International Sugar Scale.---------------------- 77
Correction of Saccharimeter to - - - - - - - - - - - - - - - - 80
Interpolation, 560 mp from 546. Imp and 578 mu ...- :
Inulin:
hydrolysis.------------ . . . . . . . . . . . . . . . . . . . . . -- 399
methylation---------------------------------- 502
preparation.---------------------------------- 398
Inversion of sucrose---...-- . . . --- - - - - - - - - - - - - - - - - - 132
by enzymes. . . . ------------------------------ 146
by hydrochloric acid.------- - - - - - - - - - - - - - - - - - 127
by invertase.--------------------------------- 146
in Candy tests. - - - ---------------------------- 387
Invertase ------------------------. . . . . . . . . . . . . . 146
activity------------------------------------- 149
Clerget divisor. ------------------------------ 152
determination of sucrose- - - - - - - - - - - - - - - - - - - - - 157
inversion of Sucrose.-------------------------- 146
preparation----------- - * ~ * * *-* - - - - - - -- * ~ * * * * * * * * * 146
purification by adsorption-- - - - - - - - - - - - - - - - - - 151
Invert Sugar---------------------------- 130, 187, 399
determination:
by polarization at two temperatures - - - - - - - 215
in molasses------ ----------...- - 188, 192, 796, 797
reduction methods -- - - - - - - - - - - - - - - - - - - - - - - 170,
173, 174, 175, 185, 192, 193, 195
effect of various reagents on rotation -- - - - - - - - - 137
in honey-------------------------------------- 233
in maple products-- - - - - - - - - - - - - - - - - - - - - - - - - - - 237
Solubility in water-- - - - - - - - - - - - - - - - - - - - - - - - - - - 362
Iodo-acetyl sugars, see Halogeno-acetyl sugars.
Iodo-heptaacetyl 4-3-glucosido-o-d-mannose,
preparation----------------------------------- 501
Iodometric determination of aldoses- - - - - - - - - - - - - 208
d-ISOrhamnose, and derivatives - - - - - - - - - - - - - - - - - 726
Isorotation, principle--------------------------- 432
ISOtherm, adsorption--------------------------- 336
Ives tint photometer-------------- - - - - - - - - - - - - - 31 |
Jackson and Mathews modification of Nyns
levulose method - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 203
Jellet halfshade polariscope - - - - - - - - - - - - - - - - - - - - - 37
polarizer-------------------------------------- 40
Jellet-Cornu, polariscope - - - - - - - - - - - - - - - - - - - - - - - 37
polarizer------------------------------------ 37
prism--------------------------------------- 37
Ketal derivatives--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 482
Ketoses, Separation from aldoses by bromine
oxidation------------------------------------- 467
Keto sugars, see Aldehydo sugars; d-Fructose.
Keuffel & ESSer color analyzer---- - - - - - - - - - - - - - - - 310
Kieselguhr, see Diatomaceous earth.
Kline and Acree, method for aldoses. -- - - - - - - - - - - 210
Königs-Knorr reaction---------- - - - - - - - - - - - - - - - 516
Königs-Martens spectrophotometer---- - - - - - - - - - 308
Lactone rule------------------------------------ 434
correlation------------------------------------ 434
optical rotations and configuration---- - - - - - - - - 434
Lactones----------------------------------- 44(), 521
formation by oxidation of Sugars-- - - - - - - - - 415, 423
Lactose:
and derivatives. ----------------- - - - - - - - - - - - - - 738
conversion of octaacetate to chloro-heptaacetyl
neolactose---------------------------------- * jº., ºd
preparation and purification----- - - - - - - - - - - - - - 467
Solubility in water.------------------------- . . 361
sucrose and, determination in mixture--- - - 189,225
Lactulose:
preparation----------------------------------- 467
ring structure--------------------------------- 416
Lamps, see Light sources.
Landolt:
polariscope tube------------------------------ 104
Sodium lamp--------------------------------- 49
Lane and Eynon, method for reducing Sugars. - - - 185
Lang, temperature coefficient of quartz - - - - - - - - - - 60
Laurent:
half-wave plate----------------------------- 37, 41
polarizers------------------------------------- 41
polarizing system, description and advan-
tages--------------------------------------- 41
Lead nitrate, basic----------------------------- 124
Lead acetate------------------------------------ 120
analysis-------------------------------------- 121
basic----------------------------------------- 12
correction for precipitate Volume -------------- 122
effect on levulose----------------------------- 124
effect on Sucrose------------------------------ 124
Polarimetry, Saccharimetry, and the Sugars
Lead acetate—Continued. Page
preparation----------------------------------- 120
Le Chatelier, temperature coefficient of quartz--- 60
Lemon flavine, preparation of l-rhamnose from -- 475
Levulose, See also d-Fructose - - - - - - - - - - - - - - - - - - - - 398
crystallography------------------------------- 543
crystallization-------------------------------- 404
from alcohol----------------- - - - - - - - - - - - - - - - 404
from Water- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 405
density of solutions--- - - - - - - - - - - - - - - - - - - - - - - - - 650
determination-------------------------------- 203
by polarization at two temperatures - - - - - - - - 217
in Condensed milk. --- - - - - - - - - - - - - - - - - - - - - ... 205
Nyns method - - - - - - - - - - - - - - - - - - - - - - - - - - - 203
Jackson and Mathews modification----- 203
dextrose and, determination in mixtures. 203, 223
24
effect of basic lead acetate - - - - - - - - - - - - - - - - l
mutarotation--------------------...-- - - - - - - 451,452
normal Weight-------------------------------- 766
precipitation of calcium levulate - - - - - - - - - - - - - 400
Dreparation----, ----. ---------. -----, -----. --- 399
refractive index of solutions. -- - - - - - - - - - - - - - - - - 670
Solubility in water------------------ . . . . . . .--- 360
Structural formula- - - - - - - - - - - - - - - - 413, 414, 416,427
Structure. -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 413,416
Ilight beams. -------------------- . . . . . . . . . . . . . . 3
coherent -- - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - 7
incoherent... --- - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - 5
Light filters, see Filters.
Ilight:
inhomogeneity - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 5
Oscillatory nature--- - - - - - - - - - - - - - - - - - - - - - - - - - - 2
polarized------------------------------------ ... 3
circular.------------------------------------ 11
elliptical------------------------------------ 8
plane--------------------------------------- 3
requisite purity. ... - - - - - - - - - - - - - - - - - - - - - - - 51, 57
Light sources, see also Particular type: sodium,
Imercury, etc - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4
Bates type, cadmium-gallium - - - - - - - - - - - - - 54, 55
Cadmium----------------------...-----------...- 52
Cadmium-gallium arc.---- - - - - - - - - - - - - - - - - - - - - 54
Daylite lamp ------------. ------------------. 311
for circular-scale polariscope - - ---------------- 46
for Colorimetry - - - - - - - - - - - - - - - - - - - - - - - - - - 312,318
for Spectrophotometry. - - - - - - - - - - - 306, 307, 308,310
gas lamp for saccharimeters - - - - - - - - - - - - . . . 88
high-pressure mercury arc. -- . . . . . . . . . . . . . . . . . 3.18
incandescent tungsten------- - - - - - - - - - - - - - - - - - 313
National Bureau of Standards lithium flame
apparatus--------...--. -----. - - - - - - - - - - - - -
National Bureau of Standards, official for
polarimetry-------------------------------- 51
IſlerCllr V-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 51, 54
rotating arc for cadmium-silver lines - - - - - - - - - 54
Saccharimetric-----------------------------. 84
Sodium arc, General Electric. -- - - - - - - - - - - - - - 49, 50
Sodium flame--- - - - -- - - - - - - - - - - - -- - - - - - - - - - - - - - - 47
Spectrum lines ------------------------------- 54
Uviarc mercury lamp -- .--------... ------------ 319
yellow-green mercury line as standard - - - - - - - - 51
Light Vector-...--... ---------------------------- 2
Lines, spectral, see Spectral lines.
Lippich, halfshade prism --------------------- 40, 41
polarizer------------------------------------ 40, 41
polarizing System, description and advantages 41
Lithium flame-----------. ---------------------- 56
National Bureau of Standards apparatus - - - - - 56
lines.--------------------------------------- ... - 56
Lothrop and Holmes, doxtrose and levulose in
honey---------------------------------------- 211
Lº: Series of spectral lines for polariscopic
WOTRS---------------------------------.
Luff-Schoorl method for invert Sugar in cane
Sugar----------------------------------------- 195
d-Lyxose, and derivatives----------------------- 740
preparation----------------------------------- 469
MacMichael viscometer------------------------ 354
Magnetic rotation - - - - - - - - - - - - - - - - - - - - - - - - - - - 17,46
Main, pot method for reducing sugars ... -- - - - - -- 199
Major and minor axes of elliptical Oscillation. --- 9
Malic acid in maple products---. - - - - - -- - - - - - - - - - 239
Maltose, and derivatives- - - - - - - - - - - - - - - - - - - ---- 742
preparation and purification------------------ 470
Steinhoff method for determination ----------- 230
Malus, polarization by reflection - - - - - - - - - --- 34, 39
d-o-Mannoheptose, cº-hexaacetate, preparation
from 8-isomer--------------------------------- 490
d-6-Mannoheptose, and derivatives------------- 745
Page
(l-Mannose, and derivatives - - - - - - - - - - - - - - - - - --- 746
a-chloro-tetraacetyl -- - - - - - - - - - - - - - - - - - - - - - -- 499
calcium chloride compounds.... -- - - - - - - - - 415,454
ring structure.------- - - - - - - - - - - - - - - - - - - 415,454
Crystallography. -- . . . - - - - - - - - - - - - - - - - - - - - - - - 543
determination as phenylhydrazone - - - - - - - - - -- 218
dicarbonate----------------------------------- 514
o'-methyl furanoside. -- - - - - - - - - - - - - - - - - - - 504,520
8-methyl pyranoside isopropyl alcoholate------ 519
o'-pentaacetate ... -- - - - - - - - - - - - - - - - - - - - - - - - - - - -. 489
g-pentaacetate- - - - - - - - - - - - - - - - - - - - - - - - - - - - - --- 488
preparation from ivory nuts. -- - - - - - - - - - - - - - - - - 471
Manometers for gas pressure, candy test- - - - - - - - - 381
Mathews, formula for determining dextrose and
levulose-------------------------------------. 223
Manostat, flow, pressure, regulation----- - - - - - - -- 376
Maple products. ------------------------------- 235
Martens photometer- - - - - - - - - - - - - - - - - - - - - - - - - - 309
types------------------------------------- 305, 308
Meade-Harris color units--- - - - - - - - - - - - - - - - - - - . 312
Meissl and Hiller method, invert Sugar -- - - - - - - - - 175
Melezitose and derivatives- - - - - - - - - - - - - - - - - - - -- 748
preparation----------------------------------- 472
preparation of turanose from --- - - - - - - - - - - - - - - 480
Melibiase, test for activity... - - - - - - - - - - - - - - - - --- 159
Melibiose and derivatives - - - - - - - - - - - - - - - - - - - - - 748
preparation from raffinose- - - - - - - - - - - - - - - - ---. 473
Melting point, determination------ - - - - - - - - - ---- 546
of Sugar derivatives--------------------------- 704
of Sugars-------------------------------------. 704
Mercaptal derivatives of sugars - - - - - - - - - - - - --- 521
aldehydo and keto derivatives from - - - - - - - - - - - -- 490
glycosides from------------------------------- 517
Mercury and Sodium lines, rotation ratio,
Quartz------------------------------, ------ 60,8
Mercury green line, official polarimetric light
SOUTC0--------------------------------------
proposed use by Bates... -- - - - - - - - - - - - - - ------- 51
Structure------------------------------------- 52
Mercury lamps:
high pressure------------------ ------------ 1
in photometry---------------- 306, 312,316,318,321
Spectral filters-------------------------------- 324
types.-------------------------------------- 51, 53
UViarc--------------------------------------- 31
Mercury spectral lines-------------- - - - - - - - - ---- 51
Meso compounds------------------------------- 419
Mesquite gum, l-arabinose from ---------------. 457
Metallic reflection ----------------------------- 20
Methoxyl determination:
Volumetric method - - - - - - - - - - - - - - - - - - - ------- 510
Zeisel method. ------------------------------. 509
Methyl arabinosides preparation-------- - - - - - - - - 514
Methylated Sugars- - - - - - ----------------------- 506
methoxyl determination-- - - - - - - - - - - - - - - - ----- 509
Methylation of Sugars:
with methyl iodide--------------------------- 506
with dimethyl Sulfate.-----------------------. 507
3-Methyl-diacetone-d-fructose, preparation-- - - - - 508
Methylene blue, indicator -- . . . . . - - - - - - - 186, 200, 201
Methyl ethers of sugars, see Methylated sugars.
Methyl 3-d-fructoside tetraacetate, preparation. 519
Methyl glucosides, optical rotation - - - - -
preparation from mercaptals- - - - - - - - - - - - - - - - -
Methyl 3-d-glucoside, tetraacetate, preparation-. 516
Methyl 4-8-glucosido-8-d-mannoside:
preparation from heptaacetate. --------------- 493
preparation from halogeno-acetate--- - - - - - - - 492
Methyl glycosides. -- - - - - - - - - - - - - - - - 423,433, 513,704
acetylated derivatives from helogeno-acetyl
SugarS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 516
configuration--------------------------------- 423
enzymatic Splitting--------------- ------ 423, 513
Methyl d-gulopyranoside, calcium chloride com-
POUIDCIS. ------------------------------------ 515
preparation----------------------------------- 515
Methyl-a-d-mannofuranoside, preparation - - 504,520
Methyl ox-d-mannopyranoside
diacetone------------------------------------- 484
monoacetone--------------------------------- 484
Methyl 3-d-mannopyranoside:
preparation of isopropyl alcoholate------------ 519
Methyl pentosans-------------------------- 243,245
Methyl tetramethyl-o-d-galactoside, prepara-
tion---------------------------------------- 506
Methyl tetramethyl-o-d-glucoside, preparation- 508
Methyl tribenzoyl-o-d-glucoside, preparation
from trityl derivative------------- - - - - - - - - - - 512
Methyl 6-trityl-o-d-glucoside, preparation------- 512
806
Circular of the National Bureau of Standards
Page
Mica-halfshade--- - - - - - - - - - - - - - - - - - - - - * - - - - - - -t: 28, 36
quarter Wave plates. - - - - - - - - - - - - - - - - - -------- 28
Wave plates--- - - - - - - - - - - - - - - - - - - - - - ---------- 28
Microchemical methods for reducing sugars------ 196
Micrometer, Rochon - - - - - - - - - - - - - - - - ---------- 3
Milk, condensed, determination of sugars---- 205, 207
Milliliter--------------------------------------- 107
Mitscherlich, improvement of Biot polariscope 36,39
Mohr cubic centimeter - - - - - - - - - - - - - - - - - - - - - - - - - 77
Moisture, change in raw Sugars. -- - - - - - - - - - - - - - - 115
determination ------------ - - - - - - - - - - - - - - - - - - - - 261
of Carbons---------------------------------. 334
of molasses--------------------------------- 262
of raw Sugars--------------------------- 261,797
method of Rice and Boleraski- - - - - - - - - - - - - - - 263
method of Spencer------ - - - - - - - - - - - - - - - - - - - - 263
Molasses:
coefficient of expansion - - - - - - - - - - - - - - - - - - - - - - - 797
determination of weight per gallon ------ - - - - - - - 251
dry Substance-------------------------------- 262
in decolorization tests - - - - - - - - - - - - - - - - - - - - - - - - 336
Schoorl method for invert sugar - - - - - - - - - - - - - - 192
Molecular rotations, see Rotations, molecular.
Molecular weights:
Sugar derivatives----------------------------- 704
SugarS---------------------------------------- 7
Monoacetone-d-glucose, preparation--------- 483,484
monocarbonate, preparation- --------------- 504
Monoacetone o'-methyl d-mannopyranoside,
preparation--------------------------------- 48
Monochromatic light:
IſlerCUTy arC- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 51,53
required for polarimetry---------------------- 40
requisite purity-------------------------- 47, 51, 57
Monosaccharides, determination. --- - - - - - - - - - - - - 206
Barfoed method.-----------. ------------------ 206
Monier-Williams modification - - - - - ---------- 207
Mounting of quartz control plates, test - - - - - 58,61,62
Mucic acid, preparation from galactose - - - - - - 218, 528
Muencke gas burner---------------------------- 49
Multiflex galvanometer---- - - --------- 318
Munson and Walker method for reducing Sugars. 170
Mutarotation, and sugars in solution. 416,439, 447, 762
coefficient------------------------------------ 44
constants, table-----------...-------------- 447, 762
effect of acids and bases - - - - - - - - - - - - - - - - - - - - - - 451
effect of metal tubes-- - - - - - - - - - - - - - - - - - - - - - - - - 451
effect of Solvent------------------------------- 453
effect of temperature-------------------------- 447
equations--------------------------------- 442, 762
equilibrium Constant ------------------------.
heat of reaction--------------------------- 447, 762
measurement--------------------------------- 446
Velocity Constants - - - - - - - - - - - - - - - - - - - - 443, 447, 762
National Bureau of Standards:
polariscopic equipment----------------------- 46
simple barley sugar test. - - - - - - - - - - - - - -------- 371
Neolactose, and derivatives--- - - - - - - - - - - - - - - - - - - 749
halogeno-heptaacetyl derivative from Octa-
acetyl lactose------------------------------- 502
preparation----------------------------------- 474
Nernst glower, saccharimetric light Source - - - - - - 90
Newkirk method, picnometer for - - - - - - - - - - - - - - - 251
Nicol prism------------------------------------ 36
description----------------------------------- 36
invention----------------------------------- 35, 39
Nomenclature, alpha and beta SugarS.----------. 424
color------------------------------------------ 301
Spectrophotometric------ - - - - - - - - - - - : - - - - - - - - - 301
Nomograph for calculating decolorization ------- 339
Normal hydrogen electrode.-- - - - - - - - - - - - - - - - - -- 286
Normal quartz plate, thickness----------------- 81
Normal Solution-------------------------------- 74
sucrose, rotation in circular degrees - - - - - - - - - - - 81
Normal weight, dextrose-----. --------------- 82, 562
levulose------------------------------------- 766
SucroSe----------- - - - - - - - - - - - - - - - - - - - - - - ---- 77,78
Nucleic acid, yeast ----------------------------- 476
preparation of d-ribose------------------------ 476
Null-point indicator, conductance bridges. ----- 267
photoelectric photometer - - - - - - - - - - - - - - - - - 1,322
Nyns levulose method-----. . . . . . . . . . . . . -------- 2:03
Jackson and Mathews modification----------- 203
Octaacetyl-4-3-glucosido-a-d-mannose, prepara-
tion------------------------------------------ 489
Page
Ofner method for reducing Sugars--- - - - - - - - - - - - - 193
Open-chain acetyl sugars, see Aldehydo Sugars.
Optical activity in organic compounds---------- 4] 7
Optical Center of gravity------------------------ 314
Optical rotation, see Rotation.
Optical Superposition principle----------------- 428
Ordinary and extraordinary beams---------- - - - 22
Orthoester derivatives of Sugars------------- 486, 492
action of acids---------------------------- 493,495
preparation----------------------------------- 492
removal of orthoester groups-------------- 492,495
Osborn and Zisch, Clerget analysis of beet
products-------------------------------------- 160
Oscillations, simple rectilinear------------------ 3
phase of ------------------------------------- 4
resultants of.--------------------------------- 5, 8
Oscillator for conductance measurements - - - - - - - 268
Oscillatory nature of light. --------------------- 2
Ost Solution for reducing sugars----------------- 204
Ostwald Viscometer- - - - - - - - - - - - - - - - - - - - - - - - - - - - 352
Oxidation of sugars, see also Aldonic; Mucic acids
bromine------------------------------ 415,467, 523
electrolytic------------------------------- 523, 524
hydrogen peroxide and iron, preparation of
d-lyxose-----------------------------------. 469
nitric acid-------------------------------- 218, 528
periodic acid---------------------------. -- 423, 529
Oxygen, action on Sugars in alkaline Solution. -- 528
Packing of Sucrose------------------------------ 408
Palladium black-------------------------------- 288
Parallelism test of Quartz control plates--- - - - - - - 57
Parker effect----------------------------------. 269
Partially acetylated Sugars - - - - - - - - - - - - - - - - - 486, 491
Pellet polariscope tube. . . ------- - - - - - - - - - - - - - - - 104
Pentaacetyl-aldehydo-d-glucose, preparation -- - - 490
Pentaacetyl-:
-3-d-fructose, preparation--------------------- 487
-8-d-galactose, preparation-------------------- 488
-keto-d-fructose, preparation------------------ 491
-o-d-mannose, preparation- - - - - - - - - - - - - - - - - - - - 489
-8-d-mannose, preparation. ------------------- 488
-o-d-talose, preparation----------------------- 487
Pentabenzoyl-d-glucose, preparation- - - - - - - - - - - - 503
Pentosans, analysis----------------------------- 241
Perbenzoic acid--------------------------------- 480
oxidation of galactal---. ----------------------- 479
oxidation of glycals--------------------------- 531
preparation----------------------------------- 480
Periodic acid, oxidation of glycosides - - - - - - - 423, 529
Permanganate method for copper--------------- 182
ph, automatic control and recording----------- 293
definition------------------------------------- 279
pH measurement------------------------------- 279
colorimetric---------------------------------- 294
buffer Solutions----------- - - - - - - - - - - - - - - - - - - 294
Gillespie method - - - - - - - - - - - - - - - - - - - - - - - - - - - 297
indicators---------------------------------- 296
potentiometric-------------------------------- 280
Phase difference-------------------------------- 5
Phase of Oscillation -----------------------------
4
Phenyl ox-d-glucoside tetraacetate, preparation -- 517
Phenyl 8-d-glucoside tetraacetate, preparation-- 517
Phenyl glycosides. ----------------------------- 516
Photoelectric cells:
photronic------------------------------------- 322
Selenium------------------------------------- 318
VaCulliſi - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 317,320
Photoelectric circuits, bridge------------------ . 320
compensating----------------------------- 319,322
Photoelectric photometers---------------------. 316
Hirschmüller--------------------------------- 318
Keane and Brice------------------------------ 321
phototube-------------------------------- 317,319
Sandera-------------------------------------- 317
Photoelectric photometry - - - - - - - - - - - - - - - - - - - - - - 316
Photogryic effect, rotation of plane of polariza-
ion------------------------------------------ 16
Photometer calibration------------------------- 306
Photometers, polarizing:
Bausch & Lomb------------------------------ 304
Gaertner------------------------------------ 307
Martens-------------------------------------- 308
Photometers, rotating sectors, Keuffel and Esser- 310
Polarimetry, Saccharimetry, and the Sugars
Page
Photometric Standards------------------------- 306
calibrated glass------------------------------- 314
Colored Solutions of Variable thickness - - - - - - - - 306
for Duboscq colorimeter---------------------- 314
Sectored disc---------------------------------- 309
Phototubes, Vacuum - - - - - - - - - - - - - - - - - - - - - - - 317,320
Planeness test, quartz control plates-------- - - - - 57
Plane parallelism, quartz control plates.--- 57, 61,62
Plane of polarization---------------------------- 3
methods for locating-------------------------- 24
by auxiliary Nicol-------------------------- 25
by reflection-------------------------------- 26
rotation discovered by Arago - - - - - - - - - - - - - - - - - 34
rotatory dispersion - - - - - - - - - - - - - - - - - - - - - - - - - 40, 64
Plane polarized light---------------------------
nature---------------------------------------- 2
production----------------------------------- 21
Plaques, for candy tests. - - - - - - - - - - - - - - - - - - - - - - 373
projected area-------------------------------- 373
Specific area---------------------------------- 374
thickness------------- - - - - - - - - - - - - - - - - - - - - - - - - - 374
Plates, see Quartz control plates.
Platinum black, deposition--------------------- 288
removal from electrodes - - - - - - - - - - - - - - - - - - - - - - 288
Plato, density of sucrose Solutions - - - - - - - - - - - - - - 253
Polariscopes, circular scale, testing---- - - - - - - 46, 553
Polariscopes and polarizers, types. --- 36,42, 43,44, 45
Polariscope tubes-----. . . . ----------------. ----- 102
aCCuracy------------- - - - - - - - - - - - - - - - - - - - - - - - - - 105
Cover glasses---------------------------------- 106
Landolt-------------------------------------- 104
Pellet---------------- - - - - - - - - - - - - - - - - - - - - - - - - 104
temperature correction----------------------- 105
types---------------------------------------- 102
water-jacketed.------ - - - - - - - - - - - - - - - - - - - - - - 104, 105
Polariscopic equipment, National Bureau of
Standards------------------------------------ 4
Polarization:
at other than standard temperature----------- 94
by double refraction-------------------------- 13
by reflection---------------------------------- 18
discovery by Malus---------------------- 34, 39
high temperature------------------------- 232,233
apparatus---------------------------------- 233
tubes--------------------------------------- 105
law of proportionality of ------------------- 34, 39
raw and refined Sugar------------------------- 115
rotational dispersion of plane of.------------ 40, 64
Polarization reactance, electrode.---------------- 266
Polarizers, Brace Sensitive Strip----------------- 41
elliptic--------------------------------------- 30
Jellet--------------------------------------- 37, 41
Laurent--------------------------------------
Lippich------------------------------------ 40, 41
polariscope and, types ------------------ 36, 42, 45
Polarizing Systems:
TaCé---------------------------------------- 41
Cornu---------------------------------------- 37
Jellet--------------------------------------- 37, 41
Laurent-------------------------------------- 41
Lippich------------------------------------ 40, 41
Polaroid----------------------------------------
Potassium d-arabonate, preparation from
levulose--------------------------------------
Potassium chloride solution:
conductance standard, preparation - - - -------- 271
table of Conductivity - - - - - - - - - -------------- 272
for buffers------------------------------------ 294
Potassium dichromate cell.--------------------- 84
Potassium dichromate filter - - - - ---------------- 84
Potassium hydrogen fluoride, anhydrous, prep-
aration --------------------------------------- 4
Potentiometer---------------------- 281, 282,283, 290
Leeds & Northrup, type K--------------- 281, 282
rheostat-------------------------------------- 323
Preparation of sugars and derivatives, see in-
dividual Sugars and type of derivatives-- 456, 482
Pressure, (see Atmospheric, Barometric and
Vapor pressure).------------------------- 286,368
Purification of sugars and derivatives, see In-
dividual sugars and derivatives.
Purity, apparent------------------------------- 406
definition------------------------------------- 406
determination-------------------------------- 407
table of factors-------------------------------- 702
Page
Purity, true------------------------------------ 406
definition------------------------------------- 406
determination-------------------------------- 406
Purity of light, requisite for polarimetry---- 47, 57
Purity requisite for quartz control plates________ 57
Pyranose form---------------------------------- 414
Pyridine rearrangement of aldonic acids-- 524,528
Quartz:
double refraction----------------------------- 13
photogyric effects----------------------------- 16
rotation ratio for A=5461 A. and 5892.5 A -- - 60, 80
rotatory dispersion------------------------- 81, 86
temperature coefficient of rotation - - - - - - - - - - 60, 92
Quartz control plates--------------------------- 5
axis error-------------------------------- 58,61, 62
apparatus----------------------------------
limit------------------------------------- 58, 61
Certification-------------------------------- 62, 91
for Correcting to International Sugar Scale. --- 80
Int. Comm. Specifications------------------ 61, 62
measurement of rotation-------------------- 60, 61
mounting----------------------------------- 58, 59
“Shake test”------------------------------ 58, 60
National Bureau of Standards specifications-- 61
normal, thickness-----------------------------
Optical homogeneity--------------------- 57, 61, 62
parallelism, testing---------------------------
plane parallelism ------------------------ 57, 61, 62
planeness test-------------------------------- 57
purity, tests---------------------------------- 57
requirements--------------------------------- 57
Special tests---------------------------------- 63
temperature correction by - - - - - - -------------- 94
Quartz Wedge compensator, Soleil - - - - - - - - - 37, 39,64
Quartz wedge Saccharimeter, see Saccharimeter- 64
Quisumbing and Thomas, Incthod ſor reducing
SugarS---------------------------------------- 173
Racemic Substances---------------------------- 419
Raffinose, and derivatives---------------------- 750
Crystallography------------------------------- 543
Creydt formula------------------------------. 143
determination---------------------------- 156, 159
acid inversion-------------------------- 156, 160
enzyme inversion--------------------------- 159
in beet molasses------------------------------ 796
preparation and purification------------------ 475
preparation of melibiose from----------------- 473
Ratios of rotation, mercury and Sodium lines, for
quartz------------------------------------ 60, 80
for Sucrose------------------------------------ 81
Ratios of reducing powers (table)--------------- 191
Raw Sugar-------------------------------------- 115
Clarification----------------------------------- 119
customs regulations--------------------------- 781
determination of dextrose and levulose --- - - - - 227
determination of moisture---------------- 261, 797
determination of reducing sugars------------ 170,
173, 174, 175, 185, 192, 193, 195
determination of Sucrose---------------------. 116
direct polarization---------------------------- 116
mixing--------------------------------------- 115
moisture absorption -------------------------- 115
Sampling and mixing------------------------- 115
Reducing powers, ratio of (table) - - - - - - - - - - - - - - - 191
Reducing Sugars, see also Copper reduction meth-
Ods, and Sugars, reducing------------------- 165
aldoses, iodometric method for------------ 206, 208
classification------------------------------ 167, 417
chemical methods for determination ---------- 165
definition--------------------------------- 167, 416
in alkaline Solution--------------------------- 165
Reduction of halogeno-acetyl Sugars to glycals - - 532
Reduction of Sugar lactones.---------------- 456,465
Reduction products of SugarS.------------------- 530
Refined Sugar, see Sugar.
Reflectance measurements.---------- 307, 308,309,310
from Scale readings - - - - - - - - - - - - - - - - - - - - - - - - - - ... 310
of Sugar--------------------------------------- 322
Spectral--------------------------------------- 307
Reflectance standard--------------------------- 310
White plate----------------------------------- 323
Reflection, polarization by, discovered by
Malus-------------------------------------- 34, 39
808
Circular of the National Bureau of Standards
Page
Reflection, metallic. . . . . -- - - - - - - - - - - - - - - - - - - - - - - 20
Refractive index----------- - - - - - - - - - - - - - - - - - - - - - 254
International Commission Scale - - - - - - - - - - - - - 255
methods of determining - . . - - - - - - - - - 258
of crystals.
dextrose, anhydrous-- - - - - - - - - - - - - - - - - - - - - - , 546
dextrose, hydrate--- - - - - . . . . . . . . . . . . . . . . . . . . 540
levulose- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 543
SucroSe - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 535, 536
of Solutions----------------------------------- 254
levulose------------------------------------ 670
Sucrose - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 254,652
Refractorneters. -- - - - - - - - - - - - - - - - - - - - - - - - - - - - 254
Refractornetry---- - - - - - - - - - - - - - - - - - . . . . . . . . . . . 254
Regulations, U. S. Treasury---------. --...------- 781
Resorcinol test - - - - - - - - - - - - - - - - - - - - - - - - - -------- 235
Relative retardation--- - - - - - - - - - - - - - - - - - - - - - - - - 5, 27
Imeasurement--- - - - - - - - - - - - - - - - - - - - -* - ~ * - - - -- 29, 32
Resistance box- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 321
Resultants. -- - - - - - - - - - - - e- - - - - - - - - - - - - - - - - - - - - - - 5
of circular Oscillations. --- - - - - - - - - - - - - - - - - - - 12
of parallel rectilinear oscillations . . . . . . . . . . . . 5
of perpendicular rectilinear oscillations. . . . . . . . 8
Retardation, relative - - - - - - - - - - - - . . . . . . . . . . . 5, 27
measurement. - - - - - - - - - - - - - - - - - - - - 29, 32
Reversal of sodium lines--------- . . . . . . . . . . . . . . 48
l-Rhamnose, and derivatives - - - - - - - - - - - - - - - - - - - 750
preparation from lemon flavine - - - - - - - - - - - - - - - 475
5-tosyl-InonoacetOne- - - - - - - - - - - - - - - - - - - - - - - - - - 505
Ribbon filament lamp, as Saccharimetric light
SOllſce - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 90
d-Ribose, and derivatives--- . . . . . . . . . . . . . . . . . . . . 752
conversion to allose and altrose derivatives-- - - 527
preparation from nucleic acid. . . . . . . . . . . . . . . . . 476
l-Ribose, and derivatives- - - - - - - - - - - - - - - - - - - - - - 753
Ring structure of SugarS- - - - - - - - - - - - - - - - - - - - - . 414
Rochon prism - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 33, 39
Rooms, thermostated.------- - - - - - - - - - - - - - - - - - - - - 97
Rotational Viscometers - - - - - - - - - - - - - - - ---------- 354
MacMichael ---------------------------------- 354
Stormer-------------------------------------- 355
Rotating arc for cadmium-silver spectral lines. - 54
Rotation:
discovery of laws by Biot. - - - - - - - - - - - - - - - - - 34, 35
magnetic----------------------------------- 17, 46
measurement in circular degrees --- - - - - - - - - - - - 33
measurement in Sugar degrees - - - - - - - - - - - - - - - - 64
molecular:
aldonic acids, lactones, amides and phenyl
hydrazides----------------------------- 435
definition----------------------------------. 36
differences-------------------------------- 428
for substances of like configuration.------- ... 433
sugars and derivatives-- - - - - - - - - - - - - - - - - -. ... 704
normal sucrose Solutions------ - - - - - - - - - - - - - , 81
of plane of polarization--------------------. 16
discovery--------------------------------- 34, 39
of quartz control plates, measurement - - - - - - 60, 61
temperature coefficient - - - - - - - - - - - - - - - - --
ratios, for quartz and SucroSe- - - - - - - - - - - - - - - 80, 81
Specific------------------------------------- 35, 74
defined by Biot---------------------------. 35
definition-------------------------. ------ 35, 74
dextrose--------------------------------- 8
formula----------------------------------- 35, 74
levulose - - - - - - - - - * * - - - - - - - - - - - - - - - - - - - - - - * 56
relation to saccharimeter calibration-----. -- 74
Sll CFOSè - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ºr - ºr * - 82
Bates and Jackson values. . . . . . . . . -------- 82
variation with concentration... -- - - - - - - - - - - 82
Sugar derivatives------------ -------------- 704
SugarS- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 704
Rotatory dispersion-------------------------- 40, 64
normal sucrose Solution--------------------- 81, 86
Quartz-------------------------------------- 81,86
Saccharic acids--------------------------------- 528
Saccharimeters.
adjustable sensitivity type-------------------. 70
bichromate filter for-------------------------- 84
Calibration------------------------------------ 73
correction to International Sugar Scale.-- - - - - - 80
effect of temperature change on--------------. 92
Fric---------------------------------- 65, 68, 69, 70
historical development - - - - -------------------
light sources for, see Light Sources.
modern types----------------------------
Saccharimeters—Continued. Page
Quartz control plates for, see Quartz control
plates.
quartz wedge, constants.-------------------- 73, 80
Scales----------------------------------------- 73
Bates and Jackson.-------------------------- 7
French------------------------------------- 75
International Commission---------------- 77, 79
Ventzke (German) - - ----------------------- 77
Soleil, quartz wedge------------------ 38, 39,66, 67
Saccharimetric temperature coefficient for su-
CTOS8----------------------------------------- 93
Saccharimetric temperature corrections, ſor use
in tropical countries-------------------------- 94
Saccharose, Sée Sucrose.
Sampling Sugars and molasses- - - - - - - - - - - - - - 115,786
Sand, for moisture determination.--------------- 262
Saturation relations of Sugars------------------- 362
Scale comparison and conversion factors-- - - - - 83, 84
Scales method for reducing Sugars. - - - - - - - - - - - - - 189
Scales, saccharimeter, see Saccharimeters, scales.
Schedules, fee---------------------------------- 553
Schlemmer, modification of Clerget method - - - - 163
Schoorl method for invert Sugar in Cane molasses 192
Schrefeld, modification of Clerget method - - - - - - 129
Sectored disks-------------------------- 309, 310, 312
Sensitive strip polarizer------------------------- 4
Sensitive strip system, Brace, description. ------ 41
Sensitive tint plate, Soleil---------------------- 39
Shake test, for mounting of quartz control plates-58.60
Short tube viscometers----- a- - - - - - - - - - - - - - - - - - - 353
Sichert and Bleyer method for reducing mono-
Saccharides----------------------------------- 206
Silica lamp------------------------------------- 51
Silver-cadmium arc, rotating- - - - - - - - - - - - - - - - - - - 54
Silver carbonate, preparation. ------------------ 514
Silver lines------------------------------------ 54
Silver oxide, preparation ------------------------ 507
Silver-silver chloride electrode - - - - - - - - - - - - - - - - - - 292
Sodium acetate, anhydrous, preparation-------- 488
Sodium carbonate as light Source, oxyhydrogen
flame----------------------------------------- 48
Sodium flame sources, Landolt table------------ 49
Sodium lamp:
arc Spectra------------------------------------ 51
electric--------------------------------------- 49
General Electric---------------------------- 49, 5
Landolt-------------------------------------- 49
National Bureau of Standards type with so-
dium carbonate----------------------------- 4
Osram-------------------------------------- 49, 50
Pribram-------------------------------------- 49
Schmidt and Haensch -- - - - - - - - - - - - - - - - - - - - - - - 49
Zeiss--------------------------- - - - - - - - - - - - - - - 49
Sodium lines, reversal of.----------------------- 48
structure at different intensities- - - ----------- 48
structure by echelon Spectroscope------------- 48
Sodium and mercury lines, ratio of rotation:
for quartz---------------------------------- 60, 80
for Sucrose------------------------------------ 81
Sodium methylate, catalyst for deacetylation - - - 494
Soleil, quartz wedge compensator---- - - - - - - 37, 39,64
Solids, determination-------------------------- 261
Solubility---------------------------------- 359, 441
dextrose in levulose Solutions----------------- 361
dextrose in water. - - - - - - - - - - - - - - - - - - - - - - - - - - - 359
invert Sugar in Water------------------------- 362
lactose in Water------------------------------- 361
levulose in water----------------------------- 360
sucrose in invert Solution --------------------- 364
Sucrose in Water------------------------------ 359
relations of Sugars- - - ------------------------- 441
Somogyi micromethod ſor dextrose - - - - - - - - - - - - 196
d-Sorbose:
crystallography------------------------------- 543
l-Sorbose, and derivatives---------------------. 754
Source and purification------------------------ 479
Soxhlet Solution, see also Munson and Walker. - . 170
Specific absorptive index - - - - - ------------------ 303
Specifications:
Bates Sugar flask----------------------------- 108
Cover glasses--------------------------. ------ 106
for quartz control plates, National Bureau of
Standards----------------------------------- 61
for quartz control plates, Int. Comm------- 61, 62
sugar, based on candy testS.----------------. 387
thermometer----------------------------- 109,382
Polarimetry, Saccharimetry, and the Sugars
Page
Specific conductance, equation. ---------------- 268
Specific gravity:
by hydrometer------------------------------- 249
by picnometer----------...---------- ---------- 250
Specific rotation, see Rotation, specific.
Spectral filtors:
for 560 mp. ---------------------- - - - - - - - - - - - - - - -- 314
for mercury lines - - - - - - - - - - - - - - - - - - - - - - - - - - - - 324
Spectral lines as light sources. --------- - - - - - - - - - 54
Cadmium---------* -- — — — — — — — — — — — — — — — — — — — — — — — — — . -- 54
lithium--------------------------------------- 56
TherCury-------------------------------------- 51
Silver----------------------------------------- 54
Sodium----------------------- * - - - - - - - - - - - - - - -
Spectral reflectance measurement.-- 307, 308,309, 310
Spectral transmittancy measurement---------- y
308, 309, 310
Spectrophotometer. .--------------------------- 304
Bausch & Lomb------------------------------ 304
definition-------------------...---------------- 304
Gaertner------------------------------------- 307
Keuffel & Esser---------------------...------- 310
Rönigs-Martens----------- - - - - - - - - - - - - - - - - - - - 308
Spectrophotometric definitions - - - - - - - - - - - - - - - - 301
Spectrophotometric nomenclature- - - ----------. 301
Spectrophotometry----------------------------- 304
abridged-------------------------------------- 311
Spengler, Tödt, and Scheuer method for reduc-
ing Sugars------------------------------------- 194
Stability of sugar, see Candy test.
Standard Samples------------------------------- 551
dextrose-------------------------------------. 551
SuðroSe--------------------------------------- 551
Stanek, modification of Clerget method---, - ... 162
Steinhoff method for dextrose, maltose, and dex-
rin------------------------------------------ 230
Stereoisomerism of SugarS.------------------- - - - 420
Steuerwald, modification of Clerget method. --. 163
Stormer Viscometer-----------------------...----. 355
Structure of mercury green line --- - - - - - - - - - - - - - - 52
Sucrose—Refers to the pure substance, its chem-
ical and physical properties and derivatives
and to its analytical determination in sugar
products, See also Sugar.
analysis------------------------------------- 396
and derivatives-----------------------------. 755
ash determination. ------------------------- 396
boiling points of Solutions---...------------- 365,694
boiling point elevation of solutions, equation. 366
Crystallography----------------------------- 534
density of Solutions----------------------- 253,626
determination:
Clerget method---------------------------- 152
direct method.------------------------------ 116
effect of lead acetate on polarization - - - - - - - - - - 124
heat of combustion------------ - - - - - - - - - - - - - - - 551
heptamethyl, preparation -------------------- 507
influence of Salts on rotation-----------------. 139
inversion------------------------------------- 132
by hydrochloric acid----------------...------- 127
by invertase. ---------------------------, -, - 146
influence of reagents on rotation - - - - 136, 137, 139
temperature effect -------- - - - - - - - - - - - - - - - - 13
Velocity---------------------------------. 132
lactose and, determination of mixtures. - . 189,225
normal Weight------------------------------ 77,7
packing-------------------------------------- 408
purification----------------------------------- 392
Bates and Jackson -------------------, ------ 392
Herzfeld------------------------------------ 392
International Commission------------------ 392
raffinose and, determination of mixtures ----. 143,
146, 156, 159, 160
reducing action on Fehling Solution-------- . . . 168
refractive indices of crystals--------------- 535, 536
refractive indices of Solutions---------- - - - 254,652
rotation of normal Solution - - - - - - - - - ---------- 81
rotation ratio for X-5461 and X-5892.5- - - - - - - - - 81
rotatory dispersion ------------------------- 81, 86
Specific rotation------------------------------ 82
specific rotation and concentration.------ - - - - - 82
temperature coefficient of rotation ------------ 92
temperature coefficient, Saccharimetric-------- 93
Solubility in Water---------------------------- 359
Solubility in invert Solution------------------- 364
Standard Sample------------------------------ 551
Sucrose, etc.—Continued.
Structural formula. --------------------------- 416
Sugar—Refers to commercial cane and beet prod-
ucts, see also Sucrose; Sugars.
adulteration---------------------------------- 791
Colorimetry, summary of procedure----------- 332
Color Standards------------------------------- 334
dry Substance in------------------------------ 261
effect of lead acetate on polarization - - - - - - - - - - 124
granulated, reflectance------------------------ 321
invert, see Invert sugar.
mixtures, analysis---------------------------- 214
Browne formula---------------------------- 222
Mathews formula- - - ----------------------- 223
polarization of-------------------------------- 115
Quality defects-------------------------------- 387
raw, see Raw Sugar.
refined, “strengthening” of - - - - - - - - - - - - - - - - - - - 388
reflectometry--------- - - - - - - - - 307, 308,309,310,322
Solutions for colorimetry----------- - - - - - - - - - - - 2
filtration----------------------------------- 326
preparation--------------------------------- 326
White, moisture--. -- - - - - - - - - - - - - - - - <- - - - - - - - - - - 397
polarization-------------------------------- 115
reducing Sugars in -----------...------------ _ 397
Sugar balance. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 112
Sugar degrees, measurement of rotation in - - - - - - 64
Sugar flasks - - - - - - -----------------------, - - - - - 1()8
Sugar juices, control of pH------ - - - - - - - - 279, 292, 29
Sugar mixtures. --------------------------...---- 214
Sugar photometer, Keane and Bricc-- - - - - - - - - - - 32!
Sugar Scale------------------------------------- 73
French--------------------------------------- 7:
German or Ventzke - - - - - - - - -----------...-----. 77
International Commission ---, - - - - - - - - - - - - - - - 77
Amsterdam -------------------------------- 79
Bates-Jackson ------------------------------ 7
Herzfeld-Schönrock--------- - - - - - - - - - - - - - - - - 78
Sugars—Refers to Sugars other than sucrose (re-
ducing sugars, rare sugars and their properties
and derivatives), see also Particular sugar or
derivative.
Sugars:
configuration --------------------------------- 426
Crystallography --------------------------- - - 533
derivatives------------------------------- 482, 704
in Solution------------------------------------ 439
absorption Spectra-------------------------- 439
determination------------------------------ 441
effect of alkali------------------------------ 165
equilibrium - ------------------------------ 439
effect of calcium chloride ------- -- - - - - - - - - - 453
effect of Solvent--------------------------- 453
effect of temperature------ - - - - - - - - - - - - - - - - 448
modifications present----------. . . . . . . . . 414, 416
reactions revealing equilibrium state-- - - - - - 455
reaction with bromine_-- - - - - -- - - - - - - - - - - - - - - 454
relation of equilibrium state to configura-
tion----------------- - - - - - - - - - - - - - - - - - - - - - - 439
maximum rate of Solution - - - - - - - - - - - - - - - - - - - - 441
mixtures, temperature corrections for--- - - - - - - 96
mixtures (analysis) -------------------------. 214
dextrose and levulose--- - - - - - - - - - - - - - - - - 223, 224
dextrose, maltose, and dextrins - - - - - - - - - - - -. 230
three Sugars-------------------------------. 225
two Sugars---------------------------------. 222
reducing, Crystallization-------------------. 441
mutarotation--------------------------- 439, 762
ring structure--------------------------------. 414
Sulfated ash----------------------------------- 23
Symmetry elements, class 4--------------------. 534
class 6--------------------------------------- 541
Tables, list.------------------------------------ XVII
d-Talonic acid, preparation--------------------. 528
d-Talose:
and derivatives------------------------------. 756
o:-bromo-tetraacetyl--------------------------. 500
monobenzoate-------------------...-----------. 479
... or pentaacetate-------------------------------- 487
º E.;; from galactal--------------------- 479
" separation from d-galactose------------------. 480
*talonic acid----------------------------------. 528
Temperature coefficient - - - - - - - - - - - - - - - - - - - - - - 60, 92
Conductance-------------------------------- . . 273
mutarotation----------------------------- 447, 762
optical rotation of sucrose solutions--- - - - - - - - - 92
quartz Wedge Saccharimeter------------------- 92
810
Circular of the National Bureau of Standards
Temperature coefficient—Continued. Page
rotation of quartz--------------------------- 60,92
Saccharimetric, for sucrose -------------_____ 93
Temperature control--------------------____ 98, 102
Temperature corrections-------------------_____ 92
Brix Spindles, tables-------------------------- 624
by quartz control plate----------------------- 94
for polariscope tubes-------------------_______ 105
for Sugar mixtures---------------------------- 96
glass Volumetric apparatus - - - - - _ _ _ _ 612
quartz wedge saccharimeter and sucrose solu-
tions--------------------------------------- 93
refractometers-------------------------------- 256
Saccharimetric----------- - - - - - - - - - - - - - - - - - 94, 96
Temperature, standard for volumetric appa-
ratus----------------------------------------- 107
Tests (fee schedules)--------_______________ - - - - - 551
Cover glasses---------------------------------- 553
flasks----------------------------------------- 550
general instructions--------------------------- 552
polariscopes------------------------------- 46, 553
Quartz plates--------------------------------- 553
planeness----------------------------------- 57
purity of quartz-------------, -------------- 57
Saccharimeters-------------------------------- 554
thermometers--------------------------------- 554
Weights--------------------------------------- 556
Tetraacetyl-d-fructose, preparation - - - - - - - - 492
Tetraacetyl-3-d-xylose, preparation - - - - - - - - - - - 89
Thermal mutarotations_--________________ 448, 450
Thermometers--------------------------------- 109
for use in candy tests------------------------- 382
ice baths for testing--------------------------- 110
Specifications----------------------------- I09, 382
Thermostats------------------------------------ 97
*-------------------------------------------- 97
Water----------------------------------------- 97
Thiosulfate method for copper... . . . . . . . . . . j8ſ)
p-Toluenesulfonyl derivatives of sugars ---- 505
Transmittancy, from scale readings--------- 307, 309
Trehalose, and derivatives---- - - - - - - - - - - - - - - - 757
Crystallography------------------------------- 543
Treasury regulations-----------------__________ 781
tion------------------------- * - - - - - - - - - - - - - - - - 32
Trier, Sugar------------------------------------ 786
Trimethylinulin, preparation--_________________ 508
Triphenylmethyl, see Trityl.
Trity] derivatives of sugars--------------------- 51]
Trityl groups, determination.------------------- 512
hydrolysis------------------------------------ 512
True purity - - - - - - * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 406
Tubes (polariscopic) ---------------------------- 102
8CCuraCy-------------------------------------- 105
temperature corrections------------ - - - - - - - - - - - 105
types----------------------------------------- 102
Tungsten arc, as light source------------------- 90
Turanose, and derivatives---------------------- 758
preparation from melezitose. ----------------- 48()
Turbidity, absolute-------------------- 344, 347, 350
relative----------------------------------- , 349
Turbidity and absorbancy measurement, with-
Out filtration--------------------------- 322, 345
Keane and Brice----------------------------- 321
Wees----------------------------------------- 323
Zerban and Sattler--------------------------- 345
Turbidity index-------------------------------- 323
Turbidity measurement------------------------ 341
Balch method-------------------------------- 341
With Spectrophotometer-------------------- 341
With simple instruments.-------------------- 342
With Zeiss nephelometer---------------------- 342
description of instrument------------------- 342
procedure of Landt and Witte -------------- 349
procedure of Zerban and Sattler - - - - - - - - - - - - 345
Ubbelohde viscometer-------------------------- 353
Ultra filtration--------------------------------- 148
Uronic acids, determination-------------------- 219
WASHINGTON, March 5, 1942.
Page
U. S. Treasury customs regulations------------- 781
Uviarc, mercury lamps------------------- 51, 53,319
Vacuum evaporation of sugar Solutions--------- 393
Valve, needle, for gas burner-------------------- 380
Vapor pressure and concentration of Solute in a
liquid - * * 3
Vapor pressure lowering and boiling point
elevation------------------------------------- 367
Vector, electric, magnetic and light------------- 2
Wentzke, improved Biot polariscope---------- 36,39
(German) Saccharimeter Scale----------------- 77
Viscometers------------------------------------ 352
calibration------------------------------------ 355
Capillary tube-------------------------------- 352
falling ball------------------------------------ 354
rotational------------------------------------- 354
Short tube------------------------------------ 353
Viscosity of Sucrose solutions - - - - - - - - - - - 350,357,671
Visual Spectrophotometric apparatus. ---------- 304
Volume of lead precipitate---------------------- 122
Volumetric flasks------------------------------- 106
Volumetric methods for reducing Sugars - - - - - - - - 185
Lane and Eynon----------------------------- 185
Luff and Schoorl----------------------------- 195
Ofner----------------------------------------- 193
Scales---------------------------------------- 139
Schoorl--------------------------------------- 192
Spengler, Tödt, and Scheuer------------------ 194
Vosburgh, rotation of Sugar mixtures. ---------- 138
Walden inversions---------------------- 486, 505, 516
in relation to orthoester reaction ------ 486, 493, 516
in relation to Königs-Knorr reaction------ 486,516
Walker, method of inversion-------------------- 132
Walker, Munson and, method.----------------- 170
Water-jacketed polariscope tube---------------- 103
Water thermostats----------------------------- 97
Wave lengths specified by International Com-
mission--------------------------------------- 62
Wave plates------------------------------------ 28
Wedge, See Quartz wedge.
Weighing of sugar, Customs Regulation-------- 783
Weights---------------------------------------- 110
analytical------------------------------------ 111
Certification---------------------------------- 111
normal:
dextrose--------------------------------- 82, 562
levulose------------------------------------ 670
SuCrOS8----------------------------------- 77,78
reference Standards--------------------------- 111
Sugar----------------------------------------- 110
testing---------------------------------------- J 12
Weight per gallon determination - - - ------------ 251
Welsbach mantle, light Source------------------ 88
Westphal balance---” -------------------------- 253
de Whalley method for invert sugar - - - - - - - - - - - 201
White sugar, see Sugar, white.
Wiley desiccating caps------------------------. 105
Willstätter and Schudel, method for aldoses--- 210
Winton lead number--------------------------- 238
d-Xylose, and derivatives----------------------- 759
determination------------------------ 210, 243, 245
preparation from Corn CobS-----------------... 481
9-tetraacetate--------------------------------. 489
Yeast, preparation of invertase from ------------ 146
Yeast nucleic acid, preparation of d-ribose from - 476
Zeiss-Pulſrich photometer---------------------- 315
Zeiss nephelometer, description------------. ---- 342
Sauer’s discussion---------------------------- 344
Zeiss immersion refractometer------------------ 259
Zerban, study of Clerget method - - - - - ---------- 145
Zerban and Wiley method for dextrose and
levulose in raw Sugars------------------------ 227
Zerban and Sattler, vacuum filter-------------- 328
Zerban, Sattler and Lorge, turbidity measure-
ment 345
O
Date Due

JAN 16 1964
...UNIVERSITYQEMGHGAN
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3 9015 06797.7713 .
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}