Liquid chromatographic determination of less polar ginsenosides in processed ginseng

Reversed-phase LC with an evaporative light scattering detector (ELSD) is u sed for the determination of less polar ginsenosides in processed ginseng. These ginsenosides include ginsenosides F-4, Rg(3), Rg(5), Rg(6), Rk(1), Rk (3), Rs(3), Rs(4), and Rs(5). The method used a C-18-bonded silica column w ith a CH3CN/H2O/CH3COOH gradient elution. (20R) and (20S) epimers and geome tric isomers at the C-20 position of ginsenosides, which are not generally separated by amino columns, were now clearly separated. (C) 2001 Elsevier S cience BN. All rights reserved.