RESUMEN
Objective To explore the enhanced separation behavior of ferulic acid in organic solution by nanofiltration. Methods In the experiment, molecular weight cut-off (MWCO) of nanofiltration membrane, ethanol concentration, and solution pH were selected as influencing factors to find the sensitive region of ethanol concentration and pH on the retention rate of ferulic acid with Box-Behnken central composite experiment design. And then, the separation rule of ferulic acid with organic solution was analyzed, the correlation between mass transfer coefficient and concentration of organic solvent was fitted with the changed organic solution by nanofiltration mass transfer mathematical model. Results Experiments indicated that the enhanced separation behavior appeared and the mass transfer coefficient decreased as the ethanol concentration increased from 20% to 40% with MWCO 450 and pH 8.0. Under the same condition, the enhanced separation behavior happened as the solvent was changed into methanol and acetonitrile, and the enhanced effect was positively correlated with the concentration of the three common organic solvents, the effect rule was ethanol ≈ methanol > acetonitrile material. Conclusion The enhanced separation effect of nanofiltration was related to the type and concentration of organic solvent. And taking ferulic acid as an example, the mechanism of nanofiltration separation in the environment of organic solution was studied, and the results provided references for nanofiltration concentrate for heat-sensitive traditional Chinese medicine of phenolic acid in organic solution.
RESUMEN
Based on the nanofiltration mass transfer model, the enhanced separation behavior of ephedrine in organic solution was studied. In the experiment, the sensitive region of ethanol concentration and pH on the rejection of ephedrine was screened out by Box-Behnken central composite experiment design. Furthermore, to analyze the separation regularity of ephedrine and organic solution, the correlation between mass transfer coefficient and concentration of organic solvent was fitted with the changed organic solution by nanofiltration mass transfer mathematical model. Experiments showed the enhanced separation behavior, the decrease in the mass transfer coefficient while the increase in ethanol concentration from 20% to 40%, MWCO at 450 and pH 6.0. Under the same conditions, the enhanced separation behavior was appeared as the solvent changed into methanol and acetonitrile, the enhanced effect was positively correlated with the concentration of the three common organic solvents, and the effect order was acetonitrile>ethanol>methanol. This study took ephedrine as an example, and explored the mechanism of nanofiltration separation in the environment of organic solution, so as to provide references for nanofiltration separation for heat-sensitive traditional Chinese medicine of alkaloid.