Separation and Enrichment of Four Ginsenosides of Panax Notoginseng by Foam Flotation

Four ginsenosides, Rg₁,Re,Rb₁, and Rd of Panax notoginseng were separated and enriched by foam flotation, and high performance liquid chromatography ( HPLC) was used to determine their contents. Effects of concentration and pH of the feed solution, flow rate of nitrogen gas, flotation time and NaCl concentration on the flotation efficiency were investigated. The experimental results showed that high efficiency of separation and enrichment were obtained by foam flotation. The optimum conditions for the foam flotation are feed solution concentration: 2.0 mg/mL, flotation time: 10 min, pH: 2～3, flow rate of nitrogen gas: 20 mL/min and NaCl concentration: 0.20 mol/ L.