[Determination of six ginsenosides in Panax species by high performance liquid chromatography]

A method for the determination of six major ginsenosides in panax species by high performance liquid chromatography (HPLC) with UV detection at 203 nm is described. The six major ginsenosides, which were reported to account for more than 90% of the total ginsenosides content of the panax species' root, were successfully separated using gradient HPLC. The column to be used was a Cosmosil-C18 reversed-phase, 4.6 mm i.d. x 250 mm, 5 microns (Japan), connected with a C18 guard column and the mobile phase was acetonitrile and water. The calibration curves of the six ginsenosides were all linear over the range of 25 mg/L-300 mg/L with good correlation coefficients (> 0.99). The recoveries for the ginsenosides were all above 80%. For real samples and recovery study, the major ginsenosides were ultrasonically extracted by methanol. The extracts were evaporated to 1 mL, under vacuum, at about 50 degrees C and then diluted by methanol. Just prior to HPLC analysis, the sample solutions were filtered using a C18 cartridge. This method has been successfully applied to the analysis of four commercial panax samples.