DETERMINATION OF INORGANIC SELENIUM SPECIES BY NEUTRON-ACTIVATION ANALYSIS IN AQUATIC SPECIES AFTER PRECONCENTRATION WITH AMMONIUM PYRROLIDINECARBODITHIONATE

Inorganic selenium species were determined in several parts of a fresh water fish of the species Tilapia nilotica found breeding in disused t in-mining pools. The inorganic selenium species in the monazite-rich o res can enter the human food chain through the consumption of the fish . The Se(IV) and Se(VI) species were preconcentrated by solvent extrac tion with APCDT-CHCl3 before irradiation in a TRIGA Mk.II reactor. Tot al inorganic selenium species separation was done using Chelex-100 che lating resin. Quantitative interpretations of the distribution of inor ganic selenium species in the fish are discussed with particular refer ence to the Se(IV)/Se(VI) ratio.