Precipitation Polymerization of Molecularly Imprinted Polymers for Recognition of Melamine Molecule

Molecular imprinted polymer microspheres (MIPs) were prepared by precipitation polymerization using melamine as template molecule, methacrylic acid (MAA) as functional monomer, trimethylol-propane trimethacrylate (TRIM) as crosslinking agent, acetonitrile as solvent and dispersion medium. Release of the template was performed by continuous extraction with methanol containing 10% acetic acid. The microspheres were observed by scanning electron microscopy (SEM). The perfect microspheres were produced when the addition of crosslinker was 7.48 mmol. The binding capacity of MIPs was examined, Q(max) = 68.36 mu mol g(-1), and the dissociation constant at binding site of MIPs, K(d) = 0.761, was estimated. Compared with the performance of conventional imprinted polymer, the imprinted microspheres showed high selectivity in special binding to template molecule. The imprinted microspheres could be used as the stationary phase in HPLC or SPE for selective extraction of melamine in daily products. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 962-967, 2012