Synthesis and characterization of magnetic imprinted polymer for selective extraction of cephalexin from food matrices

Abstract

Magnetic imprinted polymer having selectivity for cephalexin has been synthesized and evaluated for extraction of the antibiotic from selected food matrix. Fe₃O₄ magnetite has been prepared by co-precipitation of FeCl₂.4H₂O and FeCl₃.6H₂O in 1:2 molar ratios. Imprinted polymer has been synthesized by polymerization of methacrylic acid and ethylene glycol dimethacrylate in the presence of cephalexin over the surface of Fe₃O₄ magnetite. Selectivity of imprinted polymer over non-imprinted polymer is determined under different solvent conditions. Selectivity in both methanol and acetonitrile is found to be  > 35. Selectivity is pH  dependent in aqueous buffer solution and is in range of 2.33 to 21.3, maximum being at pH 5.0. Electrostatic interaction between amino group of cephalexin and carboxylic group in polymer appears to be main force contributing to selectivity of imprinted polymer. Cephalexin imprinted magnetic polymer extracted 80, 88, 63 and 78% cephalexin from water, milk, honey and egg white, respectively.