Rapid identification of the extent of single internal contamination with radioactive substances in man by excretion analysis

The development is described of methods used for determining the contamination of urine without correction for 40K content and with a correction for 40K which is by one order more sensitive but more time-consuming. The statistical processing of the results of activity measurements made possible the determination of the contamination limits. In different control groups the dependence was observed of the sensitivity of the method on the amount of urine analyzed, on the length of measurement and on the parallel determination of the activity in one and the same urine sample. A method was elaborated for determining 35S and 106Ru in urine consisting of mineralization of the urine by nitric acid, further chemical processing, separation and final activity measurement by a low-background measuring set. 2000 pCi 35S/l of urine and 15 pCi 106Ru/l urine may reliably be determined. For these methods mineralization losses were studied for 27 chemical elements. Losses were found only for Ru, Os, Hg, S, P, I, Br, Cl and F. For Ru the losses are 13 to 26%, for S 7 to 8%. (Oy)