Simultaneous determination of 3 kinds of rare ginsenosides in fermented ginseng by HPLC

A method for simultaneous determination of 3 kinds of rare ginsenoside Rg3, Rg3(R) and Rg5 in fermented ginseng by HPLC was established. The samples were separated by Xtimate-C₁₈ (4.6 mm×250 mm, 5 μm) using acetonitrile and 0.1% phosphoric acid solution as the mobile phase for gradient elution, and the flow rate was 1 ml/min, the column temperature was 30 ℃ and the injection volume was 20 μL. The samples were quantified by external standard method and the methodology investigation was carried out. The results showed that the rare ginsenoside Rg3, Rg3(R) and Rg5 in fermented ginseng had good linear relationships in the mass concentration ranges of 78.76-315.02 μg/ml, 39.94-159.75 μg/ml and 42.54- 170.16 μg/ml, respectively (correlation coefficient R²>0.99). The limits of detection (LOD) were 0.05 μg/ml, 0.08 μg/ml and 0.02 μg/ml, respectively, and the limits of quantitative (LOQ) were 0.15 μg/ml, 0.23 μg/ml and 0.07 μg/ml, respectively. The average recovery rates of Rg3, Rg3(R) and Rg5 at different spiked levels were 101.61%-104.10%, 100.22%-104.04%, 100.68%-102.79%, respectively. The relative standard deviation (RSD) of precision experiment and repeatability experiment results were 2.6%, 2.0%, 2.5%, 0.3%, 0.6% and 0.5%, all less than 5.0%. The method was simple, accurate and precise, and was suitable for the determination of rare ginsenoside Rg3, Rg3(R) and Rg5 in fermented ginseng.