2016 Volume 62 Issue 2+3 Pages 85-92
High-performance liquid chromatography with electrochemical detection (HPLC-ECD) by voltammetric oxidation on glassy carbon (GC) and boron-doped diamond (BDD) electrodes were performed to determine, respectively, attomole levels of catechins and femtomole levels of polymethoxyflavones. Also, these HPLC-ECD systems were applied to the analysis of green tea and Citrus depressa juice. The HPLC-ECD by voltammetric reduction on GC electrode was applicable to determine aristolochic acids in herbal medicine. Using a column-switching technique, three channel HPLC-ECD (3LC-ECD) has been developed for sensitive and simultaneous determination of phenolic acids (PHAs) and tanshinones (TANs) in Salvia miltiorrhiza. In 3LC-ECD using GC working electrodes, PHAs and TANs eluted from three columns were detected, respectively, at two oxidative (+0.7 V vs. Ag/AgCl) detection channels and at a reductive (–0.2 V vs. Ag/AgCl) detection channel. In conclusion, the present HPLC-ECD system has been characterized as a sensitive and selective analytical method for determining bioactive compounds derived from traditional Chinese medicines and plants.
