SE-81M TRACER FOR DETERMINATION OF THE CHEMICAL-YIELD IN RADIOCHEMICAL NEUTRON-ACTIVATION ANALYSIS OF SELENIUM

A radiotracer method is described for measurement of the chemical yiel d in radiochemical neutron activation analysis of selenium using the S e-75 (120 d) induced nuclide. It is based on Se-81m (57 min) radioisot opic tracer. prepared immediately before its use in the radiochemical separation procedure, by neutron irradiation of highly enriched Se-80. The recovery of selenium is calculated from the 103 keV gamma-peak of Se-81m in the separated selenium fraction used for quantitation of Se -75. The technique is illustrated by results for biological reference materials of good accuracy and reproducibility.