ABSTRACT
A simple method has been developed for estimating Ru-106 in urine. Urine samples spiked with 3-50 Bq of Ru-106 and 200 micrograms of ruthenium carrier were initially oxidized using an HNO3-H2O2 mixture. Attempts to recover ruthenium by various preconcentration methods after the initial oxidation resulted in recoveries ranging from 10-54% depending on the experimental conditions. For near quantitative recoveries, the organic matter in urine was completely destroyed by wet ashing with HNO3-H2O2 (method A) or HNO3-H2O2 followed by H2SO4 treatment (method B). The ruthenium was oxidized to RuO4 using potassium periodate and allowed to react in situ with polyethylene powder. The polyethylene powder was separated, washed and its beta activity was counted. The recovery of ruthenium was 86.9 +/- 4.6% (RSD 5.3%) in method A; and 94.4 +/- 2.6% (RSD 2.8%) in method B. The minimum detection limit achieved was 0.59 Bq/dm3. Interferences due to Cs-137 and Sr-90 were studied.
Subject(s)
Ruthenium Radioisotopes/urine , Humans , MethodsABSTRACT
A simple and rapid method for the simultaneous estimation of thorium and calcium in urine was developed. Thorium and calcium were coprecipitated as oxalates at pH 3-4 and were determined using Thoronol as reagent. A multi-wave-length linear regression analysis procedure was applied. Thorium recovery was found to be 78.3% +/- 5.1% (1 sigma) and that of calcium was 93.7 +/- 3.0% (1 sigma). The minimum detection limit for thorium was found to be 2.54 mBq/dm3. The analytical results of calcium agree very well with those determined by EDTA titrimetry.
