Fractionation of Phenolic Compounds in Red Wine

A simple analytical method was developed for the fractionation of phenolic compounds of red wine into phenolic acids (Fraction I), catechins, procyanidins, and anthocyanin monomers (Fraction II), flavonols (Fraction III), and anthocyanin polymers (Fraction IV) by passing wine through a preconditioned C₁₈ Sep-pak cartridge and eluting sequentially with methanol, 16% acetonitrile at pH 2.0, ethyl acetate, and methanol. Each fraction was then injected onto a C₁₈ HPLC column using a gradient of 3% to 100% acetonitrile in water at pH 2.6. This fractionation technique is the first step of quantitative analysis of total compounds in every fraction by a simple and rapid method: spectrophotometry.