SPECIATION OF ORGANIC SELENIUM-COMPOUNDS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY IN NATURAL SAMPLES

The importance of selenium in the environment and in biological system s is now well recognized, Its biochemical functions, e.g., its anti-ox idant role and therefore cell protecting function, as an essential con stituent of the enzyme glutathione peroxidase, has provoked a growing interest in the determination of this element. Selenoamino acids are e ssential for the understanding of the biogeochemical cycle of Se and T MSe(+) is a known urinary metabolite present at high levels when Se is taken in excess, In this work me present a hyphenated technique (HPLC -ICP-MS) available for the separation of the organic Se compounds (sel enocystine, selenomethionine and trimethylselenonium ion), The choice of column and solvents has been a critical parameter, Good repeatabili ty and excellent detection limits (less than 1 mu g l(-1) for each spe cies) have been reached for standard solutions and the application to some natural samples (enriched yeast, human serum and urine) has shown quite promising results.