Improved procedure for Pu/Am, and U isotope analysis in fecal samples

Herein, we describe an improved procedure for ²³⁸Pu, ²⁴⁰Pu, ²⁴¹Am, and natural U quantitation in fecal samples and validate it by analyzing reference samples of the intercomparison program. Interference caused by ²³⁷Np resulted in Pu content underestimation, which was corrected by the addition of an alternative tracer. Samples processed using the fusion method (to facilitate dissolution) exhibited significantly biased U contents compared to reference values, with the magnitude of the bias being dependent on the type of flux used. Conversely, the wet-ashing method afforded results closely matching reference values, being not significantly more time consuming than the fusion method. (author)