Analysis of Small Molecular Selenium Species in Serum Samples from Mercury-Exposed People Supplemented With Selenium-Enriched Yeast by Anion Exchange-Inductively Coupled Plasma Mass Spectrometry

A hyphenated technique was optimized to simultaneously determine different selenium species, including Se(IV), Se(VI), selenocysteine (SeCys), and selenomethionine (SeMet), by anion exchange chromatography (AEC)-inductively coupled plasma mass spectrometry (ICP-MS). Ammonium citrate and methanol were used as mobile phase. Mobile phase A is composed of 0.5 mM ammonium citrate + 2% (V/V) methanol, and mobile phase B is 100 mM ammonium citrate + 2% (V/V) methanol. When 93% A + 7% B were used, the four Se species can be separated in 7.5 min. The detection limits for SeCys, Se(IV), SeMet and Se(VI) were 0.34, 0.67, 1.38 and 0.63 μg L−1, respectively, according to three times standard deviation of the blank criterion. The recoveries of spiked Se(IV) in serum samples were between 93% and 107%, and the RSDs were less than 9% (n = 3). This method was applied to analyze serum samples from long-term mercury-exposed people supplemented with selenium-enriched yeast. The concentrations of total Se and Se(IV) in serum samples were found to be increased after Se supplementation. The method is simple, rapid, sensitive, repeatable, and suitable for speciation analysis of small molecular weight seleno-compounds in different biological samples.