Structural classification of flavonoids in beverages by liquid chromatography with ultraviolet-visible and electrochemical detection.

Liquid chromatography with both UV-VIS and electrochemical detection is used to structurally classify flavonoid compounds in wine and grape juice without isolation of the pure compound. Compounds are classified as flavonols, proanthocyanidins, or anthocyanidins, based on their absorption maxima. Catechol substituted compounds are identified using a dual electrode detector.