ENHANCED SENSITIVITY FOR THE DETERMINATION OF SELENIUM BY INAA

A working analytical procedure for selenium determinations by INAA, us ing gamma spectrometry with a germanium well-type detector, is present ed. The spectral Line at 400.7 keV is employed, enhanced with the effe ct of energy summing in true coincidence of cascade photons. The main advantage of the method is high efficiency and reliable, interference- free results; potential drawbacks are increases in input count rate an d pile-up losses, decrease in resolution, and sensitivity to errors in sample-to-detector geometry. The procedure is applied to certificatio n analysis of reference materials, large-area biomonitoring by oak lea ve samples, and determination of separated proteins.