Determination of selenium species in black bean protein powder by HPLC and ICP-MS

Selenium (Se) is an essential trace element for humans and has many significant physiological functions, even though the range between the essentiality and toxicity of Se is very narrow. Inorganic Se can be toxic at high concentrations, while the bioavailability of selenomethionine (SeMet) is higher than that of organic Se in living organisms. Therefore, it is of great significance to conduct Se speciation analyses. Se was determined in black bean protein powder according to the established method. The main chemical forms of Se were identified as SeMet, Se(IV), and standard substances selenocystine, along with two unknown Se species. High-performance Liquid Chromatography coupled to Inductively-coupled Plasma Mass Spectrometry is presently the most common means for Se species analysis, which has the advantages of high efficiency separation, relatively low detection limit, wide linear range, and high precision analysis.