Simultaneous determination of active ingredients in blueberry wine by CE-AD

A method based on capillary electrophoresis coupled with amperometric detection (CE-AD) has been developed for the separation and determination of kaempferol, ferulic acid, vanillic acid, caffeic acid, gallic acid and protocatechuic acid in blueberry wine for the first time. In order to get the optimum conditions of separation, the effects of working electrode potential, pH value and concentration of running buffer, separation voltage and injection time on CE-AD were investigated. Under the optimum conditions, the analytes could be separated in Na ₂B ₄O ₇-KH ₂PO ₄ buffer at pH 7.8 within 18 min. A 300 μm diameter carbon disk electrode had good current responses at +0.95 V (vs. SCE) for all analytes. The responses were linear with concentrations over three orders of magnitude with detection limits (S/N = 3) at 10 ^-8 g/mL magnitude for the analytes and the recoveries were in the range of 95.8-106.7%. The method could be successfully applied to the analysis of real sample with satisfactory results and therefore recommended for use by the quality control departments of fruit wine producers.