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 ionization has been successfully applied to the determination of trans‐resveratrol (3,5,4′‐trihydroxystilbene) in wine. Of a range of analytical conditions that were tested, optimum results were obtained by the use of reversed‐phase high performance liquid chromatography (HPLC) using a mixture of methanol and ammonium acetate as the mobile phase. The negative‐ion spectrum of trans‐resveratrol showed pseudo‐molecular ion, [M − H]−, which was the most abundant ion, and low fragment ions corresponding to the losses of hydroxyl groups of the phenol nucleus. Enhanced selectivity for the separation between trans‐resveratrol and endogenous wine constituents was afforded by sample purification with a tandem solid‐phase extraction method. The approach permits detection at low concentration of trans‐resveratrol. The combination of improved sample pretreatment and an isocratic chromatographic system in conjunction with internal standardization forms the basis of a new assay for the quantitation of trans‐resveratrol in wine. Full‐scan mass spectra were readily obtained from 8 ng of trans‐resveratrol, while a limit of detection of 200 pg (signal‐to‐noise ratio 3) was attained in the selected ion monitoring mode. The application of LC/MS to the determination of trans‐resveratrol in wines is demonstrated by the analysis of red wines. Copyright © 1999 John Wiley & Sons, Ltd.