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Determination of radioruthenium in urine
MICROCHEMICAL
JOURNAL
11, 404-407
Determination JYOTI
R.
Health Physics Division,
(1966)
of Radioruthenium BHAINDARKAR
AND
Atomic Energy
P.
R.
Establishment
Received February
in Urine’ KAMATH
Trombay,
Bombay,
India
18, 1966
Ruthenium is a very rare and little-known element. Radioruthenium is produced in fission (lo3Ru, T4 = 40 days, loORu, T+ = 1 year) and is present in irradiated atomic fuel. In the treatment of irradiated uranium for recovery of plutonium, radioruthenium is released from the fuel as nitrosyl complexes in the process solutions. The long-lived losRu is a betagamma emitter and the beta hazard comes mainly from its daughter lWRh with which it comes in equilibrium rapidly. losRu emits hard betas (3 mev) . The biological behavior of Ru has not been observed in the natural processes of body elimination. Animal experiments have shown that body metabolic processes depend on the chemical nature of Ru. Nitrosyl ruthenium is absorbed more rapidly than any other form. Maximum concentration in the body occurs in 2 hours of exposure, then the concentration falls rapidly and Ru is partially excreted in urine (3). RATE OF RTJ EXCRETION
AND FECES % DOSE (2)
Feces
Day 1 2 3 4
TABLE 1 IN URINE (RATS)
33.1 28.9 7.3 5.9
Urine 37.1 25.4 9.5 ‘1.5
7.1 1.9 1.1 0.7
4.0 2.1 1.1 0.6
Maximum permissible body burden for lo6Ru is 3 uc and the calculated rate of excretion is 0.2770. Ruthenium belongs to subgroup VIII of the periodic table. It can occur in any of the different valence states (II, III, IV, VI, VII and VIII) or as complexes. Ruthenium tetroxide and hydroxide are compounds 1 Paper presented at the Symposium Waltair, India, January 20-22, 1966.
on Nuclear
404
and
Radiation
Chemistry,
held
al
RADIO
Ru
DETERMINATION
IN
URINE
405
adapted for radiochemical separations. Ru04 is volatile and volatilization starts at 45’C and is complete at 110°C. Ruthenium is generally estimated by volatilizing RuOl under oxidizing conditions in the presence of perchloric acid or sulfuric acid. Ruthenium tetroxide is absorbed in sodium hydroxide solution and reduced to hydroxide from the ruthenate with alcohol. The hydroxide is dissolved in acid and Ru is recovered by reducing with magnesium powder. Estimations of Ru in vegetation and organic tissue have been carried out by ashing at temperatures of 450-SOO’C before chemical treatment. Ruthenium is reported to be nonvolatile at these temperatures (5). Urinary ruthenium has been estimated by direct oxidation of wet urine with acid KMnOl in a distillation set up to prevent loss of Ru on addition of the oxidant. In actual operation of the procedure, combining oxidation of organic matter and volatilization of ruthenium in a single treatment, the oxidation stage invariably resulted in frothing and froth flow-over. It was therefore necessary to introduce a preliminary treatment step to oxidize the volatile organic matter present, preventing at the same time any loss of Ru. Preliminary oxidation of organic matter in urine and other biological materials has been successfully carried out by treatment with nitric acid and hydrogen peroxide. Anderson and, McConnell have also reported that Ru04 (Ru VIII) is reduced by hydrogen peroxide in nitric acid to give a complex salt of quadrivalent Ru (I). In the procedure developed in the laboratory, urine is first heated with nitric acid-peroxide mixture and the oxidized urine is taken up to volatilize Ru04 by permanganate oxidation. The modification is found to be very useful to prevent frothing and boil over in the distillation set up. PROCEDURE Transfer into a 400-ml beaker 100 ml of urine, 10 mg of Ru carrier (RuC& solution), 10 ml of cont. HN03 and 5 ml of HzOz. Gradually heat to boil till the volume is reduced to 50 ml. Transfer the solution into a 200 ml R.B. quickfit flask to which is attached an air condenser through a quickfit bend. The collecting end of the condenser is attached to an adapter dipped into 40 ml 6M NaOH solution that has been kept cool in ice. Cool the R.B. flask and add gradually 2.5ml of cont. H2S04. Cool the flask in ice thoroughly and add 10 g KMnO+ Replace the condenser, heat strongly, and collect condensate for about 30 minutes. Dilute the sodium ruthenate solution to 2-3 1M alkali strength (4) and
406
JYOTI
R. BHAINDARKAR
add 5 ml of alcohol. Boil, Dissolve the hydroxide in of magnesium powder till addition of dilute HCl to weigh Ru and count beta
AND
centrifuge, and separate hydrated oxide of Ru. cont. HCl, dilute and reduce with the addition the supernatant is colorless. Boil with further dissolve unreacted Mg powder. Wash, dry, and activity. TABLE
CARRIER AND Anrvxrv
l”sRu activity spiked (W-4 356 178 178 178
P. R. KAMATH
EXCHANGE
2
IN THE DETERMINATION
Carrier Ru added (mid
1eeRu activity recovered (dpd
Carrier Ru recovered bd
15.4 10 7.7 7.7
254 149 134 144
11.2 8.2 6.0 6.2 TABLE
OF RUTHENIUM
IN URINE
Radiochemical recovery ($6 & la) 71.36 83.6 75.5 80.9
Carrier recovery (%)
f 5% k 3% + 45% 31 5%
71.03 82.0 77.9 80.5
3
URINE ANALYSIS added = 10 mg Ru)
CHETVIICAL RECOVERY IN ROUTINE
(Carrier Urine sample
K.R.A. M.S.I. S.R. P.T.W.
Carrier recovered bd
8.5 8.1 7.8 7.5
Chemical recovery (%b)
Urinary tolerance level
85 81 78 75
Nil Nil Nil Nil
RESULTS
Table 2 gives values for radiochemical and chemical recoveries for spiked experiments carried out to determine (a) the efficiency of the method and (b) exchange between carrier and spiked activity. Table 3 gives values for chemical recoveries in routine determinations. REFERENCES 1.
2.
ANDERSON, J. S., AND MCCONNELL, J. D. M., Some nitrates of quadrivalent ruthenium. Atomic Energy Research Establishment Harwell, U. K. Report No. C/R 1483 (1954). BRUCE, R. S., AND CARR, T. E. F., Studies in the metabolism of carrier-free Radioruthenium-II, The uptake of nitrosyl-ruthenium complexes from the gastro-intestinal tract. Reactor Sci. Technol. 14, 145-154 (1961).
RADIO
3.
4. 5.
Ru
DETERMINATION
IN
URINE
407
R. S., AND CARR, T. E. F., Studies in the metabolism of carrier-free Radioruthenium-I, Preliminary Investigations. Reactor 5%. Technol. 14, 9-17 (1961). KOLTHOFF, I. M., AND ELVING, R. J., The platinum metals. In “Treatise on Analytical Chemistry,” Vol. 8, p. 400. Wiley (Interscience), New York, 1963. WYATT, E. I., AND RICKARD, R. R., The Radiochemistry of Ruthenium. Nuclear Science Series, NAS-NS 3029 (1961). Published by Subcommittee on Radiochemistry, National Research Council. U.S.A. BRUCE,
JOURNAL
11, 404-407
Determination JYOTI
R.
Health Physics Division,
(1966)
of Radioruthenium BHAINDARKAR
AND
Atomic Energy
P.
R.
Establishment
Received February
in Urine’ KAMATH
Trombay,
Bombay,
India
18, 1966
Ruthenium is a very rare and little-known element. Radioruthenium is produced in fission (lo3Ru, T4 = 40 days, loORu, T+ = 1 year) and is present in irradiated atomic fuel. In the treatment of irradiated uranium for recovery of plutonium, radioruthenium is released from the fuel as nitrosyl complexes in the process solutions. The long-lived losRu is a betagamma emitter and the beta hazard comes mainly from its daughter lWRh with which it comes in equilibrium rapidly. losRu emits hard betas (3 mev) . The biological behavior of Ru has not been observed in the natural processes of body elimination. Animal experiments have shown that body metabolic processes depend on the chemical nature of Ru. Nitrosyl ruthenium is absorbed more rapidly than any other form. Maximum concentration in the body occurs in 2 hours of exposure, then the concentration falls rapidly and Ru is partially excreted in urine (3). RATE OF RTJ EXCRETION
AND FECES % DOSE (2)
Feces
Day 1 2 3 4
TABLE 1 IN URINE (RATS)
33.1 28.9 7.3 5.9
Urine 37.1 25.4 9.5 ‘1.5
7.1 1.9 1.1 0.7
4.0 2.1 1.1 0.6
Maximum permissible body burden for lo6Ru is 3 uc and the calculated rate of excretion is 0.2770. Ruthenium belongs to subgroup VIII of the periodic table. It can occur in any of the different valence states (II, III, IV, VI, VII and VIII) or as complexes. Ruthenium tetroxide and hydroxide are compounds 1 Paper presented at the Symposium Waltair, India, January 20-22, 1966.
on Nuclear
404
and
Radiation
Chemistry,
held
al
RADIO
Ru
DETERMINATION
IN
URINE
405
adapted for radiochemical separations. Ru04 is volatile and volatilization starts at 45’C and is complete at 110°C. Ruthenium is generally estimated by volatilizing RuOl under oxidizing conditions in the presence of perchloric acid or sulfuric acid. Ruthenium tetroxide is absorbed in sodium hydroxide solution and reduced to hydroxide from the ruthenate with alcohol. The hydroxide is dissolved in acid and Ru is recovered by reducing with magnesium powder. Estimations of Ru in vegetation and organic tissue have been carried out by ashing at temperatures of 450-SOO’C before chemical treatment. Ruthenium is reported to be nonvolatile at these temperatures (5). Urinary ruthenium has been estimated by direct oxidation of wet urine with acid KMnOl in a distillation set up to prevent loss of Ru on addition of the oxidant. In actual operation of the procedure, combining oxidation of organic matter and volatilization of ruthenium in a single treatment, the oxidation stage invariably resulted in frothing and froth flow-over. It was therefore necessary to introduce a preliminary treatment step to oxidize the volatile organic matter present, preventing at the same time any loss of Ru. Preliminary oxidation of organic matter in urine and other biological materials has been successfully carried out by treatment with nitric acid and hydrogen peroxide. Anderson and, McConnell have also reported that Ru04 (Ru VIII) is reduced by hydrogen peroxide in nitric acid to give a complex salt of quadrivalent Ru (I). In the procedure developed in the laboratory, urine is first heated with nitric acid-peroxide mixture and the oxidized urine is taken up to volatilize Ru04 by permanganate oxidation. The modification is found to be very useful to prevent frothing and boil over in the distillation set up. PROCEDURE Transfer into a 400-ml beaker 100 ml of urine, 10 mg of Ru carrier (RuC& solution), 10 ml of cont. HN03 and 5 ml of HzOz. Gradually heat to boil till the volume is reduced to 50 ml. Transfer the solution into a 200 ml R.B. quickfit flask to which is attached an air condenser through a quickfit bend. The collecting end of the condenser is attached to an adapter dipped into 40 ml 6M NaOH solution that has been kept cool in ice. Cool the R.B. flask and add gradually 2.5ml of cont. H2S04. Cool the flask in ice thoroughly and add 10 g KMnO+ Replace the condenser, heat strongly, and collect condensate for about 30 minutes. Dilute the sodium ruthenate solution to 2-3 1M alkali strength (4) and
406
JYOTI
R. BHAINDARKAR
add 5 ml of alcohol. Boil, Dissolve the hydroxide in of magnesium powder till addition of dilute HCl to weigh Ru and count beta
AND
centrifuge, and separate hydrated oxide of Ru. cont. HCl, dilute and reduce with the addition the supernatant is colorless. Boil with further dissolve unreacted Mg powder. Wash, dry, and activity. TABLE
CARRIER AND Anrvxrv
l”sRu activity spiked (W-4 356 178 178 178
P. R. KAMATH
EXCHANGE
2
IN THE DETERMINATION
Carrier Ru added (mid
1eeRu activity recovered (dpd
Carrier Ru recovered bd
15.4 10 7.7 7.7
254 149 134 144
11.2 8.2 6.0 6.2 TABLE
OF RUTHENIUM
IN URINE
Radiochemical recovery ($6 & la) 71.36 83.6 75.5 80.9
Carrier recovery (%)
f 5% k 3% + 45% 31 5%
71.03 82.0 77.9 80.5
3
URINE ANALYSIS added = 10 mg Ru)
CHETVIICAL RECOVERY IN ROUTINE
(Carrier Urine sample
K.R.A. M.S.I. S.R. P.T.W.
Carrier recovered bd
8.5 8.1 7.8 7.5
Chemical recovery (%b)
Urinary tolerance level
85 81 78 75
Nil Nil Nil Nil
RESULTS
Table 2 gives values for radiochemical and chemical recoveries for spiked experiments carried out to determine (a) the efficiency of the method and (b) exchange between carrier and spiked activity. Table 3 gives values for chemical recoveries in routine determinations. REFERENCES 1.
2.
ANDERSON, J. S., AND MCCONNELL, J. D. M., Some nitrates of quadrivalent ruthenium. Atomic Energy Research Establishment Harwell, U. K. Report No. C/R 1483 (1954). BRUCE, R. S., AND CARR, T. E. F., Studies in the metabolism of carrier-free Radioruthenium-II, The uptake of nitrosyl-ruthenium complexes from the gastro-intestinal tract. Reactor Sci. Technol. 14, 145-154 (1961).
RADIO
3.
4. 5.
Ru
DETERMINATION
IN
URINE
407
R. S., AND CARR, T. E. F., Studies in the metabolism of carrier-free Radioruthenium-I, Preliminary Investigations. Reactor 5%. Technol. 14, 9-17 (1961). KOLTHOFF, I. M., AND ELVING, R. J., The platinum metals. In “Treatise on Analytical Chemistry,” Vol. 8, p. 400. Wiley (Interscience), New York, 1963. WYATT, E. I., AND RICKARD, R. R., The Radiochemistry of Ruthenium. Nuclear Science Series, NAS-NS 3029 (1961). Published by Subcommittee on Radiochemistry, National Research Council. U.S.A. BRUCE,