Electrophoresis, Vol.31, No.13, 2192-2199, 2010
Development of CE-dual opposite carbon-fiber micro-disk electrode detection for peak purity assessment of polyphenols in red wine
A new dual opposite carbon-fiber micro-disk electrode detector was fabricated and tested for hyphenation with CE in the polyphenol determination. Under optimized conditions, CE dual opposite carbon-fiber micro-disk electrode was found able to baseline separate and determine five important polyphenols (trans-resveratrol, (+)-catechin, (-)-epicatechin, quercetin and gallic acid) in red wine within 16 min with low detection limit (0.031-0.21 mg/L) and satisfactory repeatability (2.0-3.3% RSD, n = 5). The opposite dual electrode enables simultaneous determination of CE eluents for current ratio measured at +0.8 and +1.0 V versus Ag/AgCl for the peak purity assessment. The capability to identify the presence of co-migrating impurities in given polyphenol peaks was demonstrated in a mixed standard solution with overlapping (+)-catechin and ()-epicatechin peaks and in commercial red wine with unknown impurities and confirming the reliability for polyphenol quantitation in red wine with matching migration time and current ratio.
Keywords:CE;Carbon-fiber micro-disk electrode;Dual electrode detection;Peak purity assessment;Polyphenols