CONCENTRATION AND SEPARATION OF ACTINIDES FROM URINE USING A SUPPORTED BIFUNCTIONAL ORGANOPHOSPHORUS EXTRACTANT

A method has been developed to isolate quantitatively the actinide elements (as a group) from urine samples and to produce near massless electrodeposits suitable for high-resolution α-spectrometry. The actinides are concentrated from the bulk urine sample by coprecipitation with calcium phosphate. The precipitate is then ashed, dissolved in dilute nitric acid and passed through a column of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) dissolved in tributyl phosphate (TBP) supported on an inert substrate (Amberlite XAD-7) which absorbs the actinides. The actinides are stripped from the column with dilute ammonium hydrogenoxalate, electrodeposited on a stainless-steel disk and counted on an α-spectrometer. Recoveries of added tracers are uniformly high (≥ 90%) so that samples can be routinely run without yield monitors, permitting an α peak anywhere in the spectrum to be detected with few interferences. Detection limits are influenced only by the available sample size, counting time and counter backgrounds. © 1990.