Inorganic and Organic Selenium Speciation of Seleno-Yeasts Used as Feed Additives: New Insights from Elemental Selenium Determination.

Seleno-Yeasts (SY) used as feed additives are known to contain different Selenium (Se) species. Seleno-Yeasts has been shown, on previous analytical methods, to contain selenomethionine (SeMet), selenocysteine (SeCys), selenate (Se) and selenite (Se), and various other organic and inorganic Se forms identified but rarely quantified. A new advanced method has allowed elemental Se (Se), an inorganic Se species, to be quantified, thereby obtaining better insight into the proportion of inorganic Se in SY products.