MDDC - 1005 UNITED STATES ATOMIC ENERGY COMMISSION METABOLISM OF FISSION PRODUCTS — RADIOTELLURIUM by L. Jacobson R. Over street I. Chaikoff, et al. University of California Radiation Laboratory Date Declassified: June 5, 1947 Issuance of this document does not constitute authority for declassification of classified copies of the same or similar content and title and by the same authors. Technical Information Branch, Oak Ridge, Tennessee AEG, Oak Ridge, Tenn., 4-20-49— 850-A3381 Printed in U.S.A. PRICE 10 CENTS Digitized by the Internet Arclnive in 2011 with funding from University of Florida, George A. Smathers Libraries with support from LYRASIS and the Sloan Foundation http://www.archive.org/details/metabolismoffissOOuniv METABOLISM OF FISSION PRODUCTS — RADIOTELLURIUM A. PREPARATION OF Te"''"'^' WITHOUT CARRIER By L. Jacobson and R. Overstreet OUTLINE OF METHOD In the foregoing preparation of radiotellurium without carrier, xe^'"'^^' is precipitated out of an acid fission mixture in HCl on copper sulfide. This serves to separate the element from all of the principle fission products except zirconium, columbium, and ruthenium. Following this the CuS is decomposed with HNOj and the solution is made 5N in HF. The tellurium is then removed from solution on ruthenium sulfide, separating it from zirconi m and columbium. The ruthenium sulfide is decomposed with HNO3 and the residue is boiled with HCIO4 to expel the ruthenium. The Te"''^^^ at this stage is in the hexavalent state. Where hexavalent tellurium is desired, the ele- ment is precipitated from the perchloric acid solution on a very small amount of Fe(OH)3 (50 micrograms of Fe). The iron precipitate is dissolved in dilute HNO3 and the solution is neutralized and used directly. Where quadrivalent tellurium is desired, the element is removed from the perchloric acid solution on Fe(OH)3. The iron precipitate is dissolved in HCl and the Fe is removed by extraction with isopropyl ether. The Te'^''^^^ is then reduced to the metal with hydrazine dihydrochloride and SO^. The solution is then evaporated to dryness, and the residue is digested with concentrated HNO3. This serves to decompose the hydrazine and oxidize the tellurium from the metal to the quadrivalent state. PROCEDURE The source of the tellurium sample described here was a 1.4M U02(N03)2 solution which had been prepared by dissolving a uranium slug from the pile in HNO3. Then, 750 cc of the solution was repeatedly treated with concentrated HCl and boiled to remove the nitrate ion. The nitrate free solution was then diluted to 1000 cc, and 3N in HCl. Fifty milligrams of CuCl^ was added to the uranium solution, and the solution was saturated with HgS gas. The mixture was heated to boiling and again saturated with HjS. The precipitate of CuS was centrifuged out and washed with water. The supernatant liquid and washing were combined and set aside. The CuS was dissolved in aqua regia. The nitrate was expelled from the resulting solution by re- peated evaporations with concentrated HCl. The solution was then diluted to 100 cc. and made IN in HCl. 50 mg each of barium and strontium and 10 mg each of yttrium, lanthanum, cerium, thorium and cesium were added, and the copper precipitated with H^S as before. The CuS was centrifuged out, and the super- natant liquid was discarded. The copper precipitate was decomposed by digestion with a few cc of concentrated HNO3. The re- sulting solution was diluted to about 50 cc and made 3N in HNOg. 10 mg each of yttrium, lanthanum, cerium, thorium, zirconium, columbium, and ruthenium was added. The mixture was then made 5N in HF and the rare earth fluorides centrifuged out. The filtrate was saturated with H^S gas. The material was digested on the steam bath for 15 minutes and again saturated with H^S. The ruthenium sulfide pre- cipitate was centrifuged out and washed with 5% NHjCl solution and the supernatent liquid and washings were discarded. MDDC - 1005 1 MDDC - 1005 The ruthenium sulfide was decomposed by digestion with a few cc of concentrated HNO3. 5 cc of 70% HCIO4 was added and the mixture was boiled until the ruthenium was expelled. 10 mg of ruthenium was added and the solution was again boiled to expel the ruthenium. The solution was then diluted to about 30 cc and treated with 10 mg of Fe. The solution was made alkaline with NH^OH and heated to boiling. The Fe(OH)3 was centrifuged out and washed with dilute ammonia. The supernatant liquid and washings were discarded. The iron precipitate was dissolved, 15 cc of 9N HCl, and the Fe \vas removed from the solution by repeated extractions with equal volumes of isopropyl ether. The iron-free solution was evaporated to a small volume and diluted and made 6N in HCl with a total volume of 12.5 cc. This solution was treated with 1 g of hydrazine dihydrochloride and 12.5 cc SOj- saturated water. The mijcture was boiled for several minutes and then evaporated to dryness. The residue was digested with concentrated HNO to destroy the hydrazine dihydrochloride. The solution was finally evaporated several times with concentrated HCl to remove the nitrate. The resulting solution contained the radiotellurium in the tellurite (+4) state. The total activity was approximately 120 microcuries as measured with the electroscope. Hexavalent tellurium was prepared as above, but carried only through the perchloric acid distillation. 50 jug of iron was added to the perchloric acid residue, and the solution made basic with HN4OH, The resulting Fe(OH)3 precipitate was centrifuged, washed, and taken up in a small amount of nitric acid. Upon assaying, the sample was found to contain 75% telluric tellurium and 25% tellurous tellurium. CHEMICAL TEST To a suitable aliquot of the Te'^''"^ solution, 10 mg each of tellurium, Ru, Sr, Ba, Y, La, Ce, Th, Cs, Mo, Rh, Sn and Sb were added. The solution was made 3N in HCl, heated to boiling, and saturated with S02- The resulting tellurium metal was centrifuged and washed. The filtrate and washings were combined and boiled to remove SO^. 10 mg more of tellurium was added to the solution and tellurium metal again precipitated as before. The filtrate and washings from the second tellurium precipitation were evaporated to dryness and measured. 4% of the total activity was found in this fraction, giving a minimum value of 96% for the purity of the Te^^T^iza^ B. TRACER STUDIES WITH Te'".'^^ By I. Chaikoff and Associates The tracer studies of radioactive tellurium were divided into two parts: (1) an investigation of the tetravalent form, and (2) an investigation of the hexavalent form. The same radioactive isotope was em- ployed in both cases. TETRAVALENT TELLURIUM This study was carried out on 36 rats weighing between 200 and 300 g. Three modes of administra- tion of the radioactive material were used: oral, intramuscular, and lung. The intramuscular injections (0.4—1.0 cc) were carried out via the thigh muscles of the left leg. The lung administrations (0.2 — 0.25 cc) were carried out by means of a lung cannula. The oral administrations (0.4-1.0 cc) were carried out by means of a stomach tube. Animals were sacrificed at intervals of 1, 4, 16, and 32 days after injection. There were 9 rats for each interval, 3 for each mode of injection. The injected doses were approximately 5000-6000 counts per second for the oral and intramuscular administrations and approximately 3000 counts per second for the lung administration. MDDC - 1005 The rats were placed in metabolism cages, and daily excretions of urine and feces were collected separately. The daily collection of urine and feces was facilitated by transferring the animals to clean cages every day. The old cage was washed down thoroughly with hot water after each transfer, and the washings were added to the urine. The orally and intramuscularly injected animals were placed in sepa- rate cages for the first 4 or 5 days after injection so that the excretions could be measured for each animal individually during this interval when the excreta were very active. After the fourth or fifth day the 3 animals in each group were combined in one cage and feces and urine collected in common from each group. A simple device was used to collect urine and feces separately in all cases. The three rats in each group of lung- administered animals were combined in one cage immediately after injection, no individual collection of excreta being made in this case. The rats were fed the regular stock diet and tap water ad libitum. Sampling of Tissues At the time of sacrifice each rat was anesthetized with nembutal and blood withdrawn by heart punc- ture. The blood was delivered into a weighed, porcelain, milk ashing dish, and the weight of the blood sample was obtained by difference. The animal was first skinned, then the following tissues were removed and weighed: liver, 2 kidneys, spleen, lungs, heart, brain, mesenteric lymph nodes, bone (2 femurs, 2 tibias, and 2 fibulas), tail fat, mesenteric fat, a sample of gastrocnemius muscle, 2 testes, 2 teeth (incisors), gastrointestinal tract (from the cardiac sphincter to the rectum), 2 thyroids and 2 adrenals. All of the tissues, were transferred directly to weighed, numbered, milk ashing dishes, except in the following instances: 1. Kidney — In cases where a single kidney was too active to count on our counter (for example, at an early interval after intramuscular injection) the 2 kidneys were minced well in a beaker with the aid of scissors, and 2 aliquots of the kidney mince were weighed out into previously weighed milk ashing dishes. In some cases each single kidney was placed in a milk ashing dish. When the activity was not high, both kidneys were placed together in a small beaker for ashing as described below. 2. Liver — In cases where the liver was too active to be counted in its entirety, it was first well minced with scissors and 2 aliquots weighed out into milk ashing dishes. When the entire liver could be counted, it was placed in a beaker for ashing. 3. Gastrointestinal Tract — After removal from the animal, the gastrointestinal tract was washed by forcing water through the lumen. The contents and washings were added to the feces collection of the last day. The tissue was then rinsed in tap water, blotted on a paper towel, weighed, and transferred to a beaker for ashing. 4. Muscle — The muscle sample was usually too large to be treated in a mUk dish, and therefore it was transferred to a beaker for ashing. 5. Skin and Hair — After weighing, the skin and hair sample was transferred to a large beaker for ashing. 6. Carcass — The carcass remaining after removal of all tissues was weighed and then thoroughly ground in a meat grinder. The resulting mince was reasonably homogeneous, and 2 aliquots were weighed and transferred to beakers for ashing. 7. Left leg of intramuscularly-injected animals (site of injection) — The entire left leg minus the foot was weighed and transferred to a beaker for ashing. Bone and muscle samples were then taken only from the right leg in intramuscularly- injected animals. 8. Lungs of lung-injected animals — Since the lungs might be expected to be very active in these animals, the lungs were transferred to beakers for ashing, and an aliquot of the solution of ash taken for counting. 9. Blood — When the blood was quite active, the samples taken for counting were small enough to be treated in milk ashing dishes. For the later intervals, however, the sample of blood taken for counting was too large to be treated in a milk ashing dish, and it was delivered into a weighed beaker for ashing. Blood samples were usually taken in duplicate. 10. Feces and Urine — Feces and urine were collected in beakers and were ashed directly in the beakers in which they were collected. MDDC - 1005 Ashing Procedure Experiment showed that some radioactivity was lost by ashing at temperatures as low as 300°, even after previous treatment with HNO3. For this reason a wet ashing procedure was adopted. The tissues were treated with concentrated HNO3 on the steam bath. The smaller tissues were ashed directly in the miUc ashing vessels. The larger tissues were ashed in beakers, and the resulting ash was either trans- ferred wholly to a milk ashing dish or made up to volume and an aliquot delivered into a milk ashing dish. Since all of the milk ashing dishes had previously been numbered and weighed, the weight of the ash remaining after the HNO3 treatment could be obtained simply by weighing the vessel plus the ash and subtracting the weight of the vessel. The correction to be applied for a given weight of ash was obtained from the mass absorption curve. Mass Absorption Curve Carcass ash was prepared by ashing several rats in the muffle at 500° . A saturated solution of this carcass ash in HCl was prepared and varying amounts of this solution (0.9 cc) were added to a series of 10 cc volumetric flasks containing the same amount of radioactive tellurium. Aliquots of the re- sulting solutions were pipetted into weighed milk ashing dishes, and the samples were dried on the steam bath. After drying, the weight of the ash was obtained, and the samples were counted. The counts were compared with the theoretical counts to be expected if no ash solution had been added. This procedure was carried out twice, and the mass absorption curve (Figure 1) was drawn up, plotting mg of ash against correction factor. The correction factor was that factor by which the observed number of counts had to be multiplied in order to give the number of counts which would have been obtained with no mass present. The best curve through the experimental points was a straight line. The correction factor for various weights of ash was as follows (from the absorption curve): Ash St. (mg) Factor 225 1.00 750 1.22 1200 1.42 1800 1.67 2400 1.92 3000 2.18 3600 2.43 Calculations The background of the covmter and tube used throughout most of this investigation was about 1.2 counts per second. On the bases of variations in the background over a long period of time, a figure of 0.2 counts per second was arbitrarily taken as the maximum error of the background count, and samples which contained an activity equal to background were calculated as < .2 counts per second. Samples containing between and 0.4 counts per second (after subtracting background) were assumed to have a maximum possible error of 100% and thus they were calculated as containing < twice the observed count. In this way an upper limit was set for the recovery in weak samples. For samples containing between 0.5 and 1 counts per second, only one significant figure was retained for the final recovery. HEXAVALENT TELLURIUM This study was carried out on 9 rats. Only oral and intramuscular routes of administration were employed. The time intervals were as follows: 4-day oral (3 rats), 4-day intramuscular (3 rats), and 16-day intramuscular (3 rats). The injected dose was 1.0 cc containing about 1600 counts per second. This procedure for this study was exactly the same as that described above for tetravalent tellurium. MDDC - 1005 10.0 5.0 1.0 io.5 o o UJ CO tc lU a. V) z g CO > 0.1 0.05 0.01 \o 50 100 150 200 MG Al PER CM 250 300 350 Figure 1. Al absorption curve for Te^^'jlZD. RESULTS MDDC - 1005 The results of the o 1-4 inclusive and the co 5-6. The oral studies r( absorbed by way of the lurium was deposited pr tration, the distribution the oral studies. The ra tration were surprising! the first day by way of tl equal to the daily excret dose in both oral and int with +4 tellurium. The lungs studies v due to the fact that such swallowed by the anima This tended to obscure i tellurium absorbed by v However, it was very tellurium in the lungs into the lungs. Time did not pei tation of the data pre tellurium present in v qualitative difference administration, excei mained unabsorbed a' sorption of hexavale for +4 tellurium. In one -half of that with tellurium, it seems have been reduced tt the absorbed telluriv was approximately t tellurium was emplc I. ramuscular experiments using teliurous tellurium (+4) are in Tables g experiments with telluric lelluriutn (+6) are indicated in Tables it approximately 25% of the adrnSnistered flose of the ^4 tellurium was ract. The distribution of the absorbed activity indicated that the tel- In the blood, lii/er, -and kidrsey. Following intraniuscular admlnis- r>orbed activity followed essentially the simc pattern as was noted in .iffiination of the absorbed tellurium foIlo'Aring both routes of adminis- sjid a considerable proportion of the teUuriurn wa.s eliminated during y. Thereafter the rate of urinary elimination fell sharply and bftcasae ;ay of the digestive tract. Approximately three fourths of the absorbed jiar studies was excreted during the S/.-day interval of the expcTiraents ite ur.satisfactory from the point of vie*- oi reasonably ijuanUtative data, siderable proportion of the administer id te.iiuriun-k that is invariably luse of the tecSuiique employed was absorbed from the dige.gtxve tract, erpretation as to what proportion of t!»e activity in the tissue v/as from the digestive tract ?*nd what proporti'm was absorbed through She lungs. .'it from the lung experiment that the rimouni ^j: pulmonary retention ol +4 .'lativeiy small, probably less thaji 59.- of the quantity originally introduced ire extensive studies with telluric teiluriun?, and, of course, the interpre- ts somewhat impaired because of tho f net thut approximately 25% of the tavalent preparation was in the forrri of teliurous tellurium. No majcr istribiition of the hexavalent tellurijm were noted following intrainuscuiar the fact that a signtficimtly higher proportion of the admin l.-stered dose re • site of injection. It is also apparert that ?t.t the 4-day interval the oral ab- urium was significantly less than *-as noted at the corresponding time interval of the fact that the apparent oral ribsorption in the +6 state was approximately •4 tellurium while the material used in the +6 form contained 25% oi the +4 reasonable to conclude that a corsiderable proportion of the +6 teliurium may tellurium during its sojourn in tKs digesMve tract. The rates of eliitiirjatlon of n the +6 experiments, following '.»oih oral and intramuscular administration, jame and also v/as comparable to the corresponding experiments in which +4 DISCUSSION The principle pr its oi interest arising from the results of the experiments just described are: first, tellurium, whe ler administered either in the teliurous or telluric state, is absorbed by way of the digestive tract. . seems quite possible that in '.hese experiments the +6 tellurium was not as readily taken up by way of t e digestive tract, and tiiat its assimilation takes place by its first being converted to teliurous telluriv ci, which is then absorbed; s8f;ond, the rates of elimination of absorbed tellurium in both valence states ;md by botli jral and intramuecafiir administration are rapid and essentially com- parable. The rates of excretion during the time ntervals studied indicate an approximate one-half time of retention in the body of 16 days. This is subsrant.ially less than the one-half periods of the radio- active decay of Te' " and Te"' which are 32 anc 90 days respectively. This observation places tellurium in the small list ( the long-life Jission producrs whose rates of eliniiniition are greater thai) their rates of radioactive de ly. The other members of tnis group are ruthenium, xenon, and cesium. Third, the principle organs of deposition for absorbed tfllurium are blood, liver, and kidney. On the per gram basis the kidney tissue is from 2 to 5 times nore active than ariy other of the tissues. In all of the intramuscular studies with teliurous ajid teliuric tellurium the blood was more active per gram than the MDDC - 1005 Table 1. Recovery of tetravalent radiotellurium in the tissues of the rat one day after oral or Intra- mu.sciilar administration (avg. of 3 rats). Tissue Oral Admimstraticn Per Cent Recovery Per Gram Per Organ v'. Sample IijtramwEcuiar Administration Per Cent Recoi'ery Per Gram Pfn Orgtui In SampJe Blood 0.27 4.7 0.44 0.32 5.6 0.19 Liver 0.54 4.8 4.8 0.30 2.4 2.4 Kidneys 0.52 0.87 0,87 1.5 2.4 2.4 Spleen 0.15 0.10 0.10 0.30 0.30 0.30 G.l. Tract O.IO 1.2 1.2 0.081 0.90 0.90 M. Lymph Node.? 0.07 --- 0,01 0.11 .... 0.068 Lungs 0.090 0.095 0.09a 0.14 0.21 0.21 Brain 0.012 0.021 0.021 0.014 0.025 0.025 Muscle 0.013 1.4 0.095 0.025 2,5 0.15 Heart 0.0f50 0.39 0.039 0.G93 0.070 0.070 Bone 0.055 0.74 0.089 0.32 4,2 0.26 Teeth .05 _.. .006 0.07 0.01 Left Leg ... .... .„. 4.5 54.2 54.2 Thyroid A .01 .01 .4 .0.1 .01 Adrenals A ,01 -CI .4 .01 .01 Testes 0.018 0.049 0.049 3.052 0.12 0.12 M. Fat 0.023 --„ 0.046 0.035 --_ 0.043 Tail Fat .01 ... .014 0.02 ... 0.02 Skin&Kair 0.013 0.64 0.64 0.041 i.S 1.0 Carcass 0.022 2.6 2.6 0.071 7.6 7.6 Excreta Feces 68.6 2.9 Urine 13.1. 81.7 27.3 Recovery In Tissues 11.5 71.0 Recovery in Excreta 61-7 , 27.3 Total Recov try in Animal 93.2 OtJ.S MDDC - 1005 Table 2. Recovery of tetravalent radiotellurium in the tissues of the rat 4 days after oral or intra- muscular administration (avg. of 3 rats). Tissue Oral Administration Per Cent Recovery Per Gram Per Organ In Sample Intramuscular Administration Per Cent Recovery Per Gram Per Organ In Sample Blood 0.23 4.4 0.54 0.82 16.0 0.86 Liver 0.15 1.3 1.3 0.52 4.8 4.8 Kidneys 0.53 0.98 0.98 3.3 6.0 6.0 Spleen 0.14 0.14 0.14 0.60 0.94 0.94 G. I. Tract 0.035 0.39 0.39 0.16 1.7 1.7 M. Lymph Nodes 0.048 --- 0.019 0.27 — 0.11 Lungs 0.061 0.075 0.075 0.32 0.41 0.41 Brain 0.01 0.02 0.02 0.025 0.042 0.042 Muscle 0.013 1.5 0.18 0.070 7.8 0.51 Heart 0.045 0.036 0.036 0.20 0.14 0.14 Bone 0.055 0.87 0.11 0.37 5.4 0.34 Teeth .06 .007 0.15 0.02 Thyroid .4 .009 .009 .5 .013 .013 Adrenals .2 .004 .004 .6 .02 .02 Testes 0.012 0.031 0.031 0.085 0.25 0.25 M. Fat 0.01 0.03 0.11 — 0.17 Tail Fat .004 .007 0.04 0.05 Skin & Hair 0.015 0.85 0.85 0.086 4.5 4.5 Carcass 0.029 3.7 3.7 0.15 18.5 18.5 L. Leg 2.0 21.6 21.6 Excreta Day 1 2 3 4 Recovery in Tissues Recovery in Excreta Urine Feces Urine Feces 7.4 61.6 2.13 8.5 3.1 1.14 0.89 0.71 13.5 8.9 85.5 72.0 16.2 2.1 2.9 3.8 3.3 2.9 2.6 _ 3.2 25.1 61.8 37.1 12.0 Total Recovery in Animal 94.4 98.9 MDDC - 1005 Table 3. Recovery of tetravalent radiotellurium in the tissues of the rat 16 days after oral or intra- muscular administration. Tissue Oral Administration Per Cent Recovery Per Gram Per Organ In Sample Intramuscular Administration Per Cent Recovery Per Gram Per Organ In Sample Blood 0.12 2.4 0.35 0.57 10.5 1.2 Liver 0.036 0.27 0.27 0.20 1.2 1.2 Kidneys 0.18 0.30 0.30 1.3 2.1 2.1 Spleen 0.094 0.12 0.12 0.41 0.29 0.29 G. I. Tract 0.011 0.11 0.11 0.081 0.70 0.70 M. Lymph Nodes .05 _.. .01 0.1 0.02 Lungs 0.028 0.030 0.030 0.15 0.16 0.16 Brain .01 .02 .02 0.028 0.046 0.046 Muscle 0.011 1.2 0.055 0.082 0.4 0.67 Heart 0.02 0.015 0.015 0.14 0.11 0.11 Bone 0.025 0.36 0.048 0.30 4.1 0.28 Teeth .06 .007 0.22 0.036 L. Leg .-. _._ 0.70 8.1 8.1 Thyroid .3 .007 .007 .4 .009 .009 Adrenals .2 .006 .006 .3 .006 .006 Testes 0.008 0.2 0.02 0.045 0.13 0.13 M. Fat .007 ___ .01 0.069 0.15 Tail Fat .006 .006 0.03 0.05 Skin & Hair 0.0051 0.28 0.28 0.051 2.6 2.6 Carcass 0.011 1.5 1.5 0.11 11.7 11.7 Excreta Day Urine Feces Urine Feces 1 5.6 63.7 2 1.7 6.0 3 1.3 0.81 4 0.80 0.28 5 0.60 0.29 6 0.35 0.25 7 0.21 0.27 8 0.16 0.17 9 0.16 0.13 10 0.24 0.12 11 0.17 0.14 12 0.17 0.084 13 0.14 0.081 14 0.12 0.11 15 0.090 0.078 16 0.12 0.22 11.9 72.7 Recovery in Tissue 3.5 Recovery in Excreta 84.6 15.3 2.4 3.3 3.6 3.1 2.8 2.4 1.7 2.0 1.7 1.6 1.1 1.8 0.93 1.5 1.3 1.? 0.75 1.3 0.57 1.1 0.93 0.62 0.67 0.95 0.57 0.80 0.50 0.85 0.47 0.83 0.87 38.7 20.9 30.8 59.6 Total Recovery in Animal 88.1 90.4 10 MDDC - 1005 Table 4. Recovery of tetravalent radiotellurium in the tissues of the rat 32 days after oral or intra- muscular administration (avg. of 3 rats). Tissue Oral Administration Per Cent Recovery Per Gram Per Organ In Sample Intramuscular Administration Per Cent Recovery Per Gram Per Organ In Sample Blood 0.018 0.38 0.092 0.21 3.9 0.67 Liver 0.005f > 0.056 0.056 0.10 0.72 0.72 Kidneys 0.033 0.070 0.070 0.51 0.86 0.86 Spleen .03 .03 .03 0.19 0.20 0.20 G. I. Tract .003 .03 .03 0.036 0.40 0.40 M. Lymph Nodes .04 — .006 .06 .014 Lungs .02 .02 .02 0.065 0.072 0.072 Brain .004 .006 .006 0.02 0.03 0.03 Muscle 0.003 0.4 0.04 0.035 3.6 0.26 Heart .03 .03 .03 0.04 0.03 0.03 Bone 0.01 0.2 0.02 0.16 2.4 0.14 Teeth .08 .01 0.1 0.02 Thyroid .3 .006 .006 .3 .006 .006 Adrenals .3 .006 .006 .3 .007 .007 Testes .005 .01 .01 0.026 0.064 0.064 M. Fat .009 .02 .03 .02 TaU Fat .006 .006 .01 — .006 Skin& Hair 0.001 0.08 0.08 0.020 1.0 1.0 Carcass 0.003 0.5 0.5 0.056 6.6 6.6 L. Leg 0.50 6.5 6.5 Excreta (Table 4). Oral Adm. Intramuscular Adm. Oral Adm. Intramuscular Adm. % Recovery % Recovery % Recovery % Recovery Day Urine Feces Urine Feces Day Urine Feces Urine Feces 1 10.5 67.9 1.5 21.9 20 0.059 0.065 0.50 0.75 2 2.9 3.9 1.2 1.7 21 0.054 0.72 0.74 0.82 3 0.90 0.50 1.2 1.5 22 0.045 0.17 0.45 0.77 4 0.31 0.25 0.93 1.3 23 0.059 0.04 0.59 0.71 5 0.31 0.35 0.88 .1.5 24 0.055 0.01 0.40 0.60 6 0.31 0.18 0.79 1.3 25 0.036 0.008 0.47 0.57 7 0.12 0.24 0.77 . 1.4 26 0.025 0.05 0.48 0.61 8 0.27 0.12 0.75 1.0 27 0.030 0.02 0.31 0.41 9 0.19 0.12 0.83 1.1 28 0.079 0.02 0.34 0.48 10 0.13 0.095 0.90 1.0 29 0.019 0.03 0.31 0.48 11 0.14 0.055 0.80 1.0 30 0.046 0.009 0.23 0.48 12 0.11 0.59 0.79 1.0 31 0.026 0.01 0.33 0.37 13 0.083 0.05 0.79 1.0 32 0.035 0.05 0.56 .41 14 15 16 17 18 0.20 0.097 0.13 0.088 0.097 0.17 0.094 0.17 0.24 0.05 0.66 0.81 0.72 0.70 0.68 1.1 1.0 1.0 0.89 0.94 18.0 76.5 Recovery in Tissues 0.9 in Excreta 94.5 22.0 18.2 71.9 49.9 19 0.060 0.17 0.60 0.79 Total 95.4 90.1 MDDC - 1005 11 Table 5. The recovery of hexavalent radiotellurium in the tissues of the rat 4 days after oral or intra- muscular administration (avg. of 3 rats) Tissue Oral Administration Per Cent Recovery Per Gram Per Organ In Sample Intramuscular Administration Per Cent Recovery Per Gram Per Organ In Sample Blood 0.077 1.3 0.28 0.29 4.6 0.80 Liver 0.092 0.90 0.90 , 0.14 1.0 1.0 Kidneys 0.17 0.33 0.33 0.80 1.4 1.4 Spleen 0.055 0.084 0.084 0.24 0.26 0.26 G. I. Tract 0.014 0.16 0.16 0.043 0.39 0.39 M. Lymph Nodes .05 — .013 .1 .03 Lungs .04 .05 .05 0.084 0.084 0.084 Brain .007 .013 .013 .02 .03 .03 Muscle .005 0.5 0.05 0.020 1.6 0.084 Heart .04 .03 .03 0.06 0.04 0.04 Bone .03 0.5 0.05 0.32 3.8 0.28 Teeth .09 .013 .2 — .02 L. Leg — — 3.8 35.2 35.2 Thyroid .5 .013 .013 .5 .013 .013 Adrenals .5 .013 .013 .5 .013 .013 Testes .01 .02 .02 0.03 0.07 0.07 M. Fat .02 — .03 .04 .05 Tail Fat .03 — .013 0.05 — 0.03 Skin& Hair 0.005 0.2 0.2 0.032 1.2 1.2 Carcass 0.013 1.3 1.3 0.068 6.5 6.5 Excreta Day 1 2 3 4 Recovery in Tissues Recovery in Excreta Feces Urine Urine Feces 59.0 13.3 2.6 4.7 0.25 1.3 0.17 0.79 62.0 3.6 82.1 20.1 22.4 3.0 3.5 0.73 2.3 0.51 1.8 0.80 30.0 47.5 35.0 5.0 Total Recovery in Animal 85.7 82.5 12 MDDC - 1005 Table 6. Recovery of hexavalent radiotellurium in the tissues of the rat 16 days after intramuscular administration (avg. of 3 rats). Tissue Per Cent Recovery Per Gram Per Organ In Sample Blood 0.37 6.6 1.3 Liver 0.12 1.1 1.1 Kidneys 0.80 1.3 0.3 Spleen 0.20 0.16 0.16 G. I. Tract 0.046 0.56 0.56 M. Lymph Nodes .2 ... .02 Lungs 0.11 0.13 0.13 Brain 0.02 0.04 0.04 Muscle 0.043 4.4 0.21 Heart 0.1 0.08 0.08 Bone 0.27 3.7 0.25 Teeth .3 .04 L. Leg 1.3 14.9 14.9 Thyroid .6 .02 .02 Adrenals .6 .02 .02 Testes 0.05 0.1 0.1 M. Fat 0.04 0.04 0.04 Tail Fat .03 .03 Skin & Hair 0.031 1.2 1.2 Carcass 0.074 8.1 8.1 Excreta Recovery in Tissues Recovery in Excreta Day 1 2 3 4 5 6 7 3 9 10 11 12 13 14 15 16 Feces Urine 29.5 51.5 4.2 20.4 0.92 3.0 0.75 2.1 0.62 1.5 0.36 1.1 0.47 1.1 0.72 0.90 0.67 1.0 0.57 1.0 0.59 1.1 0.63 0.96 0.55 0.93 0.48 0.95 0.58 0.81 0.55 0.65 0.73 0.61 13.4 38.1 Total Recovery in Animal 81.0 MDDC - 1005 13 liver. The blood showed the highest per organ content of tellurium, and it is of interest to note that these relative levels were maintained even up to the 32-day interval. The small but constant retention of activity in the skeleton, which showed no significant change throughout the entire 32-day interval, together with the fact that the relative proportion of activity in the skeleton as compared to other tissues was somewhat lower in the oral experiments as compared to the corresponding intramuscular experiments, suggests that there may have been from 2 to 5% of radioactive impurities in the tellurium preparations employed, such as alkaline earths, rare earths, zirconium, and columbium. It does not appear that the tellurium shows any significant tendency to either deposition or retention by the skeleton. END OF DOCUMENT UNIVERSITY OF FLORIDA 3 1262 08909 7041