Supercritical fluid chromatography of North American ginseng extract

Supercritical fluid chromatography (SFC) using supercritical carbon dioxide (scCO2) is considered as a “green” separation method, particularly suitable for the isolation of thermally unstable bioactive components. However, co-solvent and additives are often required in the mobile phase due to the poor solubility of polar components in scCO2. In the present study, the effect of temperature and pressure on the separation of ginsenosides was studied with methanol being added to the CO2 mobile phase. Acidic, basic, and ionic additives were introduced to the mobile phase, respectively, to study their effect on the separation of ginsenosides. The best separation conditions were achieved by adding trifluoroacetic acid in methanol (0.05% v/v) at 50 °C and 150 bar. A high-concentration component in the extracts from the supercritical fluid extraction of North American ginseng was isolated by SFC and identified as sucrose using NMR, HPLC, and ESI-MS. These results show that SFC is a promising technique for the separation, isolation, and identification of ginseng extracts.