title: Simultaneous determination of selenomethionine enantiomers in biological fluids by stable isotope dilution gas chromatography-mass spectrometry.
abstract: A method for the stereoselective determination of D- and L-enantiomers of selenomethionine in mouse plasma was developed using gas chromatography-mass spectrometry with selected-ion monitoring (GC-MS-SIM). DL-[(2)H(3,)(82)Se]selenomethionine was used as analytical internal standard to account for losses associated with the extraction, derivatization and chromatography. Selenomethionine enantiomers in mouse plasma were purified by cation-exchange chromatography using BondElut SCX cartridge and derivatized with HCl in methanol to form methyl ester followed by subsequent N-acylation with optically active (+)-α-methoxy-α-trifluoromethylphenylacetyl chloride to form diastereomeric amide. Quantification was performed by SIM of the molecular-related ions of the diastereomers on the chemical ionization mode. The intra- and inter-day precision for D- and L-selenomethionine spiked to mouse plasma gave good reproducibility with relative standard deviation of 3% and 3% for D-selenomethionine and 6% and 3% for L-selenomethionine, respectively. The estimated amounts were in good agreement with the actual amounts spiked, the intra- and inter-day relative error being 5% and 2% for D-selenomethionine and 2% and 1% for L-selenomethionine, respectively. The present method is sensitive enough to determine pharmacokinetics of selenomethionine enantiomers.
authors.affiliation: Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo, Tokyo 113-8421, Japan. tmatsuka@juntendo.ac.jp
authors.forename: Takehisa
authors.initials: T
authors.lastname: Matsukawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Shinohara
authors.forename: Jun
authors.initials: J
authors.lastname: Kobayashi
authors.forename: Atsuko
authors.initials: A
authors.lastname: Shinohara
authors.forename: Momoko
authors.initials: M
authors.lastname: Chiba
authors.forename: Kimiyoshi
authors.initials: K
authors.lastname: Ichida
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Yokoyama
mesh_terms: D000818:Animals; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D016018:Least-Squares Analysis; D051379:Mice; D015203:Reproducibility of Results; D012645:Selenomethionine / Q000097:blood* / Q000737:chemistry; D012680:Sensitivity and Specificity; D013237:Stereoisomerism
chemical_list: D012645:Selenomethionine