High Performance Liquid Chromatographic Separation and Quantitative Analysis of Ginsenosides Using a Polyvinyl Alcohol-Bonded Stationary Phase

Abstract

A simple high performance liquid chromatographic assay for the simultaneous quantitative analysis of seven ginsenosides, Rb1, Rb2, Rc, Rd, Re, Rf and Rg1 in commercial ginseng products is described. Chromatographic separation of the analytes was achieved in less than 20 min using a polyvinyl alcohol-bonded column with UV detection at 203 nm. Optimization of chromatographic conditions was determined by a three-factor central composite design, the variables being the percentage of acetonitrile in the mobile phase, column temperature and flow rate. A full quadratic model was found to be adequate in describing the separation of ginsenosides on the polyvinyl alcohol-bonded stationary phase. Complete separation of seven ginsenosides was achieved using acetonitrile–water (82.5/17.5) as the mobile phase run isocratically at a flow rate of 298 μL min−1 and with the column temperature at 9 °C. The developed method was validated over the range of 10–120 μg mL−1 using a 5 μL sample injection volume. Intra- and inter-day variation for three ginsenoside standards (Rf, Rd and Rb1) at three concentration levels ranged from 0.07 to 0.83% expressed as the relative standard deviation. The accuracy based on the nominal concentration values at three concentration levels was in the range 98.7–100.8%. The limit of detection was between 0.43 and 1.03 μg mL−1 while the limit of quantification was from 1.42 to 3.13 μg mL−1. The method is found to be applicable for the determination of ginsenosides in commercial ginseng products.