Sequential isotopic determination of plutonium, thorium, americium, strontium and uranium in environmental and bioassay samples

A procedure has been developed to provide sequential analysis of Pu-238, Th-230, Am-241, U-238, and Sr-90 in environmental and bioassay samples. Tracers and/or carriers (Pu-242, Am-243, U-232, and stable strontium) are added into the sample as chemical yield monitors, and then, plutonium, thorium, strontium, americium, and uranium are sequentially separated and purified by Dowex ion-exchange resin, EiChroM Sr-resin, EiChroM TRU-resin, and Chelate-100 resin, respectively. The radioactivities of Sr-90 and the actinides are measured using the liquid scintillation counter and alpha-particle spectrometer, respectively. Acidified water, glass-fiber air filter, soil, synthetic urine and synthetic feces samples of US National Institute of Standard and Technology Radiochemical Intercomparison Program(NRIP) were analyzed to verify this method. All the analytical results of Pu-238, Th-230, Sr-90, Am-241 and U-238 meet the traceability limit per ANSI N42.22, and when appropriate, evaluation of radiobioassay measurement bias and precision per ANSI N13.30. (C) 2004 Elsevier Ltd. All rights reserved.