Simultaneous LC Determination of Ginsenosides Using a Modified Extraction Procedure and an Improved Step Gradient Program

A novel, accurate and precise high performance liquid chromatographic method has been developed for simultaneous determination of seven important ginsenosides (Rg1, Re, Rf, Rb1, Rc, Rb2 and Rd) in ginseng products. The separation was performed on a Shim-pack VP-ODS column (5 μm, 150 ×2 mm i.d) with ultraviolet detection at 200 nm by using the improved step gradient elution program. The LODs (S/N = 3) were in the range 0.29 to 1.33 ng μL⁻¹. All calibration curves showed a good linearity (R² > 0.998) over the ranges tested. The recoveries obtained from spiked sample were between 95.1% and 98.7%. The proposed method was successfully applied to several ginseng pharmaceutical samples. For the sample preparation, a modified extraction method was made to improve the extraction efficiency by evaluation of five solvent systems. The results demonstrated that the extraction with methanol-water (80:20, v/v) is suitable method preferably for the extraction of the ginsenosides. On leave from Department of Pharmacy and Applied Chemistry, Jilin Institute of Chemical Technology, Jilin 132022, P. R. China