Sensitive high-performance liquid chromatography method of non-polar ginsenosides by alkaline-enhanced pulsed amperometric detection.
We determined the minute amount of non-polar ginsenosides in red ginseng with a reversed-phase high-performance liquid chromatography-pulsed amperometric detection (RP-HPLC-PAD) method. Non-polar ginsenosides efficiently extracted by ethyl acetate were well separated in 40min using a water-acetonitrile gradient eluent and detected by PAD under NaOH alkaline conditions. The ginsenoside detection limits (S/N=3) were 0.03-0.10ng. The coefficients of linear regression were 0.9972-0.9990. Intra- and inter-day precision (RSDs) was less than 8.34% and average recovery was 98.06-102.73%. The total amount of non-polar ginsenosides in hairy root of red ginseng was slightly higher than in the main root.