Quantification of selenomethionine in plasma using UPLC–MS/MS after the oral administration of selenium-enriched yeast to rats.

The in vivo determination of selenomethionine (SeMet) converted from selenium-enriched yeast (SeY) rather than the determination of in vitro hydrolyzed SeMet is a better parameter for the evaluation of SeY quality. A UPLC–MS/MS method was developed for the quantification of SeMet in rat plasma and the oral bioavailability of SeMet converted from SeY in rats. After a simple extraction with perchloric acid, SeMet and the internal standard methylselenocysteine (MSC) were separated on a C18 column with isocratic elution of water:acetonitrile:formic acid (99:1:0.1, v / v / v ) and detected in the multiple reaction monitoring mode. The method was accurate (92.6–104.3%) and precise (1.8–11.0%), and the recovery was 79.4–95.4%. It was successfully applied to pharmacokinetic and bioavailability studies of SeY in rats following the intravenous administration of SeMet and intragastric administration of SeY. SeMet in vivo , converted from SeY, is reported for the first time, and the results suggested that the SeY bioavailability in rats is 87%. [ABSTRACT FROM AUTHOR]