Rapid determination of ginsenoside Rg1, Re and Rb1 in ginseng samples by capillary electrophoresis

Abstract

A rapid and practical capillary electrophoresis (CE) method was developed for the determination of ginsenoside Rg1, Re and Rb1 in ginseng samples. Rg1, Re and Rb1 were extracted by ultrasonication with water-saturated n-butanol. The CE method was optimized with a running buffer of 20 mM borate in 30% MeOH (pH 9.67), and an applied separation voltage of +18 kV over a capillary of 50 μm i.d. × 50 cm (41.5 cm to the detector window), which gave a baseline separation of Rg1, Re and Rb1 within ca. 5 min. Under the detection at 203 nm, the method gave limits of quantification (S/N = 10) at about 5.2–7.3 μg ml⁻¹ for Rg1, Re and Rb1, whereas the overall recoveries were larger than 83.0%. The proposed method has been successfully applied to measure three different kinds of ginseng samples (10 real samples) and the contents of Rg1, Re and Rb1 in actual samples were obtained and evaluated.