title: Development of CE-dual opposite carbon-fiber micro-disk electrode detection for peak purity assessment of polyphenols in red wine.
abstract: 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.
authors.affiliation: Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, PR China.
authors.forename: Fuying
authors.initials: F
authors.lastname: Du
authors.forename: Ying Sing
authors.initials: YS
authors.lastname: Fung
mesh_terms: D002392:Catechin / Q000032:analysis / Q000302:isolation & purification; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D005419:Flavonoids / Q000032:analysis* / Q000302:isolation & purification; D005504:Food Analysis / Q000379:methods*; D005707:Gallic Acid / Q000032:analysis / Q000302:isolation & purification; D016014:Linear Models; D008839:Microelectrodes; D010636:Phenols / Q000032:analysis* / Q000302:isolation & purification; D059808:Polyphenols; D015203:Reproducibility of Results; D014920:Wine / Q000032:analysis*
chemical_list: D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D005707:Gallic Acid; D002392:Catechin