Analysis of pigmented high-molecular-mass grape phenolics using ion-pair, normal-phase high-performance liquid chromatography

A normal-phase LC method has been developed to analyze high-molecular-mass grape phenolic compounds. Samples are prepared by first isolating phenolics using C-18-SPE. The analytical method uses a silica column and gradient el ution with mobile phases of methylene chloride, methanol, formic acid and h eptanesulfonic acid. This separation enables the analysis of these compound s from grape and wine samples in the presence of anthocyanins without exten sive purification. Based on the elution order of proanthocyanidins and anth ocyanins, phenolics elute in order of increasing molecular mass. Currently, it is not possible to identify all of the components separated in the chro matogram. (C) 2000 Elsevier Science B.V. All rights reserved.