Liquid chromatography mass spectrometric determination of trans-resveratrol in wine using a tandem solid-phase extraction method

Liquid chromatography/mass spectrometry (LC/MS) with electrospray ionizatio n has been successfully applied to the determination of trans-resveratrol ( 3,5,4'-trihydroxystilbene) in wine. Of a range of analytical conditions tha t were tested, optimum results were obtained by the use of reversed-phase h igh performance liquid chromatography (HPLC) using a mixture of methanol an d ammonium acetate as the mobile phase. The negative-ion spectrum of trans- resveratrol showed pseudo-molecular Ion, [M - H]-, which was the most abund ant ion, and low fragment ions corresponding to the losses of hydroxyl grou ps of the phenol nucleus. Enhanced selectivity for the separation between t rans-resveratrol and endogenous wine constituents was afforded by sample pu rification with a tandem solid-phase extraction method. The approach permit s detection at low concentration of trans-resveratrol, The combination of i mproved sample pretreatment and an isocratic chromatographic system in conj unction with internal standardization forms the basis of a new assay for th e quantitation of trans-resveratrol in wine, Full-scan mass spectra were re adily obtained from 8 ng of trans-resveratrol, while a limit of detection o f 200 pg (signal-to-noise ratio 3) was attained in the selected ion monitor ing mode. The application of LC/MS to the determination of trans-resveratro l in wines is demonstrated by the analysis of red wines. Copyright (C) 1999 John Wiley & Sons, Ltd.