A method for analyzing 233U in biological samples

This paper describes the use of di(2-ethylhexyl)phosphoric acid (D2EHPA), a heavy metal complexing agent, in a two-phase extraction system for counting 233U in acid solutions of rat tissues, and a single-phase emulsion system liquid scintillator, referred to as TT21. The apparent advantages of the larger sample volume and lower background counting rate of the D2EHPA two-phase system were investigated as a possible solution to the need to analyze for low levels of 233U in biological samples. An experiment was initiated to compare the sensitivity and accuracy of the TT21 and D2EHPA methods. The results of each method were compared to an analysis obtained by direct α-planchet counting using a thin-window, gas-flow α-detector. (author)