title: Determination of aminothiols by liquid chromatography with amperometric detection at a silver electrode: application to white wines.
abstract: Liquid chromatography coupled to a silver electrode based flow-through amperometric detector (LC-EC-Ag) was developed for the determination of aminothiols in white wines. The C18 reversed phase LC system operated in the isocratic mode at 0.7 mL min(-1) and used an acidic mobile phase composed of formic acid, EDTA, sodium nitrate, sodium hydroxide, and methanol 1% (v/v) at pH 4.5. The working electrode operated at 0.08 V vs Ag/AgCl, 3M KCl and its manual cleaning was realized once a month by smoothing on a polishing cloth. The analyzed aminothiols were resolved and eluted within 4 min, and all standard curves were linear in the range 2×10(-7)-2×10(-5) M. The analyzed wine samples needed no preparation other than dilution with the mobile phase. The concentration of cysteine (CYS), homocysteine (HCYS), glutathione (GSH) and N-acetylcysteine (NAC) in bottled white wines, determined by the method of standard addition, was found to be in the low μM range (0.2-2 mg L(-1)) depending on the wine type and its age.
authors.affiliation: Université Libre de Bruxelles, Faculty of Pharmacy, Brussels, Belgium.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Sarakbi
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Aydogmus
authors.forename: Angela
authors.initials: A
authors.lastname: Dago
authors.forename: Dominique
authors.initials: D
authors.lastname: Mertens
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Dewert
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Kauffmann
mesh_terms: D000603:Amino Acids, Sulfur / Q000032:analysis*; D002853:Chromatography, Liquid / Q000379:methods; D004563:Electrochemistry / Q000379:methods; D005978:Glutathione / Q000032:analysis*; D017736:Ion-Selective Electrodes; D012834:Silver / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000032:analysis*; D014920:Wine / Q000032:analysis*
chemical_list: D000603:Amino Acids, Sulfur; D013438:Sulfhydryl Compounds; D012834:Silver; D005978:Glutathione