title: Identification of the major selenium compound, Se-Methionine, in three yeast (Saccharomyces cerevisiae) dietary supplements by on-line narrowbore liquid chromatography-electrospray tandem mass spectrometry.
abstract: On-line monitoring of six Se-compounds was accomplished by using an XTerra MS C18 column coupled to electrospray tandem mass spectrometry (ES-MS-MS). In view of the nature of the compounds, the positively charged ion pairing agent tetraethylammoniumchloride (TEACl) was added to the mobile phase. The HPLC-ES-MS-MS method was optimized with six commercially available Se-compounds. Substitution of the analytical column by the narrowbore type significantly enhanced the sensitivity of the method. We were able to detect the m/z of these six molecules on-line. Furthermore, all product ions could be monitored. The method was applied to three different yeast-based supplements. They were submitted to proteolytic digestion and screened for their Se-content by HPLC-HG-AFS (hydride generation-atomic fluorescence spectrometry). By application of on-line narrowbore HPLC-electrospray tandem mass spectrometry, the main compound present in these three supplements, Se-Methionine, could be measured on its m/z and its product ions. The method can be further extended for on-line measurement of different Se-species in complex matrices
authors.affiliation: Ghent University, Department of Analytical Chemistry, Proeftuinstraat 86, B-9000 Ghent, Belgium. emmie.dumont@ugent.be
authors.forename: Emmie
authors.initials: E
authors.lastname: Dumont
authors.forename: Koen
authors.initials: K
authors.lastname: De Cremer
authors.forename: Marijn
authors.initials: M
authors.lastname: Van Hulle
authors.forename: Cyrille C
authors.initials: CC
authors.lastname: Chéry
authors.forename: Frank
authors.initials: F
authors.lastname: Vanhaecke
authors.forename: Rita
authors.initials: R
authors.lastname: Cornelis
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D019587:Dietary Supplements / Q000032:analysis*; D012015:Reference Standards; D015203:Reproducibility of Results; D012441:Saccharomyces cerevisiae / Q000737:chemistry*; D012645:Selenomethionine / Q000032:analysis*; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013054:Spectrophotometry, Atomic
chemical_list: D012645:Selenomethionine