A HPLC fluorescence-based method for glutathione derivatives quantification in must and wine

A simple and automated high performance liquid chromatography (HPLC) method for the separation and quantitative determination of γ-glutamylcysteine and reduced glutathione (GSH) in wines is reported. This technique involves the use of a pre-column derivatization with 2,3-naphthalenedialdehyde (NDA), an isocratic separation in presence of β-cyclodextrine and a fluorimetric detection. The quantification of oxidized glutathione (GSSG) has also been studied, for the first time in wines, using an additive pre-derivatization step for reduction using glutathione reductase. The method has been designed for use in laboratories with limited equipment. The assay has been optimized and presents very good performances in terms of sensitivity and selectivity. Then, it has been validated for linearity, LOD, LOQ, precision and accuracy.