DETERMINATION OF TRACE AMOUNTS OF COPPER AND SELENIUM IN BIOLOGICAL SAMPLES BY CHEMICAL-SEPARATION PRIOR TO NEUTRON-ACTIVATION ANALYSIS

It was found that Cu and Se can be relatively easily and accurately de termined by preconcentration of Cu and Se prior to the determination b y neutron activation analysis with the short-lived IRN's (Indicator Ra dionuclides) Cu-66 and Se-77m. The method consists of wet acid digesti on followed by coprecipitation with lead tetramethylene-dithiocarbamat e. The precipitate was collected, irradiated and counted. The validity of the method was confirmed both by internal checks, as the measureme nt also by Se-75 and by the use of two reference material of biologica l origin. The limit of detection was found to be 20 ng Se and 50 ng Cu for a 0.1 g sample.