title: Chiral speciation and determination of selenomethionine enantiomers in selenized yeast by ligand-exchange micellar electrokinetic capillary chromatography after solid phase extraction.
abstract: A new phenylalanine derivative (L-N-(2-hydroxy-propyl)-phenylalanine, L-HP-Phe) was synthesized and its chelate with Cu(II) (Cu(II)-(L-HP-Phe)(2)) was used as the chiral selector for the ligand-exchange (LE) chiral separation of D,L-selenomethionine (SeMet) in selenized yeast samples by micelle electrokinetic capillary chromatography (MEKC). In order to improve the sensitivity of MEKC-UV, two-step preconcentration strategy was employed, off-line solid phase extraction (SPE) and on-line large volume sample stacking (LVSS). D,L-SeMet was first retained on the Cu(II) loaded mesoporous TiO(2), then eluted by 0.1 mL of 5 mol L(-1) ammonia, and finally introduced for MEKC-UV analysis by LVSS injection after evaporation of NH(3). With the enrichment factors of 1400 and 1378, the LODs of 0.44 and 0.60 ng mL(-1) for L-SeMet and D-SeMet was obtained, respectively. The developed method was applied to the analysis of D,L-SeMet in a certified reference material of SELM-1 and a commercial nutrition yeast, and the results showed that most of SeMet in the SELM-1 selenized yeast was l isomer and the recovery for L and D isomers in the spiked commercial nutrition yeast was 96.3% and 103%, respectively. This method is featured with low running cost, high sensitivity and selectivity, and exhibits application potential in chiral analysis of seleno amino acids in real world samples.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, China.
authors.forename: Jiankun
authors.initials: J
authors.lastname: Duan
authors.forename: Man
authors.initials: M
authors.lastname: He
authors.forename: Bin
authors.initials: B
authors.lastname: Hu
mesh_terms: D020374:Chromatography, Micellar Electrokinetic Capillary / Q000295:instrumentation / Q000379:methods*; D012441:Saccharomyces cerevisiae / Q000737:chemistry* / Q000378:metabolism; D012645:Selenomethionine / Q000737:chemistry* / Q000302:isolation & purification; D052616:Solid Phase Extraction / Q000379:methods*; D013237:Stereoisomerism
chemical_list: D012645:Selenomethionine