A new application of charged aerosol detection in liquid chromatography for the simultaneous determination of polar and less polar ginsenosides in ginseng products

Introduction Conventional liquid chromatographic methods coupled with ultraviolet or evaporative light scattering detection are not sensitive enough to determine both polar and less polar ginsenosides at low concentrations. Objective To establish a liquid chromatography-charged aerosol detection method for the simultaneous determination of polar and less polar ginsenosides in a variety of ginseng products Methods Fourteen polar and less polar ginsenosides were extracted and concentrated by solid phase extraction. These were subsequently baseline-separated on a conventional reversed-phase C ₁₈-column (250 mm × 4.6 mm, 5 μm) with a simple mobile phase consisting of water and acetonitrile. Components were then detected by means of charged aerosol detection. Results The method developed allowed the simultaneous determination of six polar ginsenosides (Rg₁, Re, Rb₁, Rc, Rb, Rd) and eight less polar ginsenosides (Rg₆, F₄, Rk₃, Rh₄, Rg₃(S), Rg ₃(R), Rk₁, Rg₅) in a single chromatographic run. Further, the method was linear (R² > 0.99), accurate (relative recoveries, 90-112%), and precise (intraday RSD < 5.7% and interday RSD < 10.6%) within the concentration range tested. The method sensitivity was measured in terms of the limit of detection, which ranged from 0.5 to 4.0 μg/mL. Conclusion Concentrations of 14 ginsenosides were determined simultaneously in one homemade red ginseng and 13 commercial ginseng products of different types (liquid and solid samples), and results showed that ginsenoside content varied significantly among the samples tested. The method developed could serve as a useful analytical tool for the quality control of ginseng products.