Determination of selenium in biological materials by neutron activation analysis

Abstract

The concentration of selenium in biological material, e.g., human blood serum, was determined by neutron activation analysis, with prior sample decomposition by wet digestion, followed by coprecipitation with bismuth and lead tetramethylenedithiocarbamate as a means of pre-concentration. Selenium was determined by measuring the gamma-ray photopeak of the short-lived radionuclide ⁷⁷Se^m(t_½= 17.4 s). The selenium concentration in the sera ranged from 101.3 to 116.3 ng ml^–1(mean, 108.2 ± 4.5 ng ml^–1). The validity of the method was checked using the certified biological reference materials NBS SRM 1577 Bovine Liver and IAEA dried animal whole blood (A-2-1974), for which the concentrations of selenium were found to be 1.05 ± 0.05 and 0.56 ± 0.06 µg g^–1, respectively. The detection limit for selenium was 17 ng per millilitre of blood serum.