Determination of aminothiols by liquid chromatography with amperometric detection at a silver electrode: Application to white wines

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• 作者：Ahmad Sarakbi ; Zeynep Aydogmus ; Angela Dago ; Dominique Mertens ; Jean-Yves Dewert ; Jean-Michel Kauffmann ; ^{jmkauf@ulb.ac.be}
• 关键词：Silver ; Amperometry ; Aminothiols ; Glutathione ; Wine ; Chromatography
• 刊名：Analytica Chimica Acta
• 出版年：2013
• 出版时间：5 July, 2013
• 年：2013
• 卷：786
• 期：Complete
• 页码：22-28
• 全文大小：896 K

文摘

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, 3 M 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 ¡Á 10^?7-2 ¡Á 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 ¦ÌM range (0.2-2 mg L^?1) depending on the wine type and its age.