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 determined by preconcentration of Cu and Se prior to the determination by neutron activation analysis with the short-lived IRN's (Indicator Radionuclides)⁶⁶Cu and^77mSe. The method consists of wet acid digestion followed by coprecipitation with lead tetramethylenedithiocarbamate. The precipitate was collected, irradiated and counted. The validity of the method was confirmed both by internal checks, as the measurement also by⁷⁵Se and by the use of two reference material of biological origin. The limit of detection was found to be 20 ng Se and 50 ng Cu for a 0.1 g sample.