Chiral liquid membrane for enantioselective separation of racemic ibuprofen by l-tartaric acid derivatives†
The chirality of drugs plays a significant role in most chemical and biochemical process. In this paper, a chiral liquid membrane using L-tartaric ester dissolved in n-octane as liquid membrane phase and polyvinylidene fluoride hollow fibers as membrane support was investigated to separate racemic ibuprofen. For L-dipentyl tartaric ester, the separation factor was 1.18. The favorable L-dipentyl tartaric ester concentration was 0.20 mol L−1. With an increase of flow rates on two sides, a flux change of mass transfer in stripping phase was not observed. The same trend is obtained in feed phase. The concentration of both R-ibuprofen and S-ibuprofen in stripping phase increased with an increase of pH value. The best pH in stripping phase was 2.5 and the separation factor was about 1.2. The best separation factor was up to 1.38 after a six-level experiment.