Scaffold membranes for selective adsorption of α-tocopherol by phase inversion covalently imprinting technique

A molecular-imprinted membranes targeted to α-tocopherol (α-Toc) were prepared by phase inversion of polymer containing covalently bound template group to the polymer through ester group. For preparation of such polymer, a template-containing monomer, α-tocopherol methacrylate (α-TMA) was synthesized and copolymerized with acrylonitrile (AN). Phase inversion of the AN copolymer was carried out from the DMSO solution in water non-solvent. After membrane formed, removal of the template was performed in treatment with HCl acid solution. It was observed that the amounts of α-Toc bound to imprinted and non-imprinted membranes in ethanol/water (1:1%, v/v) were 20.8 ± 0.4 and 2.2 ± 0.1 μmol/g, respectively. Scatchard analysis indicated that the imprinted membranes exhibited high affinity and good selective binding of α-Toc relative to its analogs, δ-Toc, and 4-chromanol (4-Chr). Evidences showed that separation was achieved with separation factor of 15.5 for α-Toc/4-Chr in ethanol/water 1:1% (v/v) solution by simple filtration procedure with high flux permeation.