Element selective characterization of stability and reactivity of selenium species in selenized yeast

The concerted application of element specific atomic spectral detection for chromatographic eluent monitoring allows previously unexploited qualitative and quantitative analytical concepts to be developed for the determination of selenium species. Selenium speciation is, vital in order to better understand its metabolism and biological significance in clinical chemistry, biology, toxicology, and nutrition. Fluoroacid ion pair HPLC with ICP-MS detection and GC derivatization with atomic emission detection (AED) together aid analysis and elucidation of reaction pathways of selenium compounds in high selenium enriched yeast, as used widely in nutritional and clinical cancer preventative studies. Comparisons between currently produced and archived selenized yeasts show major differences in speciation. The formation of selenomethionine selenoxide and the identification of Se-S bonded S-(selenomethyl)-cysteine in archived nutritional yeast may be important for short and long term stability and nutritional activity studies.