Straightforward method to quantify GSH, GSSG, GRP, and hydroxycinnamic acids in wines by UPLC-MRM-MS.

A novel, robust and fast ultrahigh performance liquid chromatography–multiple reaction monitoring mass spectrometry method has been developed for the simultaneous quantification of reduced glutathione (GSH), oxidized glutathione (GSSG), grape reaction product (GRP) and hydroxycinnamic acids in wine. The method was evaluated in terms of linearity, precision, accuracy, limits of detection and quantification, stability and matrix effects. Quantitative recovery (74–110%) and satisfactory interday precision (RSD <14%) were achieved for all target compounds. No significant matrix-dependent suppression/enhancement effects were observed. To demonstrate the method applicability, white, rosé and red wine samples with different levels of oxidation were analyzed. Levels of GSH and GSSG varied from 1.63 to 9.91 mg/L and from 0.32 to 3.33 mg/L, respectively. Levels of caftaric acid ranged from 2.57 to 293.07 mg/L. Levels of GRP were between 28.35 and 114.20 mg/L.