Quantitative Determination of Selenium Species in Se-enriched Yeast Using Liquid Chromatography-Hydride Generation Atomic Fluorescence Spectrometry
A rapid and sensitive method has been developed for the simultaneous determination of four selenium species Se?,Se?,selenomethionine,and Se-methylselenocysteine in Se-enriched yeast by liquid chromatography-hydride generation atomic fluorescence spectrometry( HPLC-HG-AFS). The isolation of the analytes from yeast samples was accomplished by protease  and trypsin enzymatic digestion. The target compounds were separated on a PRP-X100 anion exchange column and analyzed by HG-AFS. The mobile phase was 20 mmol /L( NH4)2HPO4. Good linearity was obtained for all the selenium species,with linear correlation coefficients higher than 0. 9996. The LODs of the four species were between 0. 5 and 5. 0 μg /kg.Average recoveries for the four analytes were in the ranges of 82. 5%- 101. 2%,with intra- and inter-day RSD lower than 8. 6% and 14. 5,respectively. The proposed analytical method is simple,sensitive,with low operation cost,making it applicable for the determination of the selenium species in Se-enriched feeds.