Chiral separation of D,L-tyrosine through nitrocellulose membrane

Enantioselective membrane was prepared using nitrocellulose as membrane material. The flux and permselective properties of membrane using water solution of D,L-tyrosine as feed solution were studied. The top surface and cross-section morphology of the resulting membrane were examined by scanning electron microscopy. The optical resolution of over 85% enantiomeric excess was achieved when the enantioselective membrane was prepared with 25 wt % nitrocellulose and 15 wt % N,N-dimethylformamide in the casting solution of methanol, 10°C temperature of water bath for the gelation of the membrane, and the operating pressure and the feed concentration of the D,L-tyrosine were 6 kgf/cm² and 0.25 mg/mL, respectively. Since the nitrocellulose contains a large amount of chirality active carbons on the backbone structure and is possible to form helical structure, it is considered to be the reason for the enantioselectivity of the membrane. This is the first report that nitrocellulose can be used as a membrane material. This work indicates that the large-scale purification of chiral molecules from racemic mixtures will be realized by the enantioselective membrane technique in the near future and that the enantioselective nitrocellulose membrane could soon become very attractive for industrial uses. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011