Determination of Bioactive Components in Polygonum perfoliatum L. by Capillary Electrophoresis with Electrochemical Detection

Abstract The major bioactive components in a Chinese herb named Polygonum perfoliatum L . including ferulic acid, vanillic acid, quercetin, caffeic acid and protocatechuic acid were simultaneously determined by capillary electrophoresis with electrochemical detection (CE‐ED) in this paper. The effects of working electrode potential, pH and concentration of running buffer, separation voltage, and injection time on CE‐ED were investigated. Under the optimum conditions, the five analytes could be separated within 17 min at a separation voltage of 18 kV in 10 mmol· L −1 phosphate buffer (pH 9.2). A 300 µm diameter carbon disk electrode generated good responses at +0.95 V (vs. SCE) to the five analytes. The response was linear over three orders of magnitude with detection limits (S/N=3) ranging from 7.1×10 −8 to 9.3×10 −8 g·mL −1 for the analytes. This proposed method could be successfully applied to the analysis of the real samples with relatively simple extraction procedures and satisfactory results.