Alkaloid extraction from herbs by emulsion liquid membrane process

Abstract

The extraction equilibrium of synthetic berberine and crude berberine solution were studied at various conditions of pH (pH 8, 9, 10, 11 and 12) with three solvents (n-hexane, kerosene, and paraffin at 25 ํC). In each case the solution was stirred at 240 rpm for 96 hrs. The experimental results showed that at each extraction equilibrium, the distribution (partition) coefficient (KD) of berberine/n-hexane is higher than berberine/kerosene and berberine/paraffin. It was also found that KD increased with the increasing of pH. In this research kerosene is a selected solvent for emulsion liquid membrane process (ELM). The experiment of ELM extraction was devided to 2 parts. Firstly, batch synthetic berberine extraction was conducted at various conditions of external phase pH (pH 8, 9, 10, 11 and 12), concentration of surfactant in kerosene (1, 3, 5 and 7% of Span-80 dissolved in kerosene) and concentration of internal phase (0.1, 0.01, 0.02 and 0.03 M HCl solution). It was found that at room temperature the suitable conditions of synthetic berberine extraction are pH 11, the concentration than initial synthetic berberine solution. The percentage of berberine extraction was 80 and 99 within 1 and 4 minutes, respectively. Secondly, batch crude berberine extration was conducted by the same process. The experimental results showed that the suitable conditions of crude berberine extraction are pH 12, the concentration of Span-80 in kerosene and HCl at 1% (v/v) and 0.03 M, respectively. It can extract 4.19 times higher concentration than initial crude berberine solution. The percentage of berberine extraction was 70% within 1 minute. The model that can predict the batch berberine extraction rate by ElM was also presented in this study.