Determination of Phenolic Constituents of Biological Interest in Red Wine by Capillary Electrophoresis with Electrochemical Detection

Abstract

A simultaneous determination of trans-resveratrol, (−)-epicatechin, and (+)-catechin in red wine by capillary electrophoresis with electrochemical detection (CE-ED) is reported. The effects of the potential of the working electrode, pH and concentration of running buffer, separation voltage, and injection time on CE-ED were investigated. Under the optimum conditions, the analytes could be separated in a 100 mmol/L borate buffer (pH 9.2) within 20 min. A 300 μm diameter carbon disk electrode has a good response at +0.85 V (vs SCE) for all analytes. The response was linear over 3 orders of magnitude with detection limit (S/N = 3) ranging from 2 × 10^-7 to 5 × 10^-7 g/mL for all analytes. This method has been used for the determination of these analytes in red wine without enrichment, and the assay result was satisfactory. Keywords: trans-Resveratrol; (−)-epicatechin; (+)-catechin; capillary electrophoresis; electrochemical detection