Magnetic imprinted polymer was prepared by polymerization of methacrylate and ethyleneglycoldimethacrylate in the presence of oxytetracycline on the surface of iron magnetite. Selectivity of prepared polymer was calculated from ratio of partition coefficient of oxytetracycline for imprinted and non-imprinted polymer in water, acetonitrile, methanol and at different pH in aqueous buffer. pH of solvent exhibited pronounced effect on selectivity. Selectivity at pH 7.0, 6.0 and 5.0 was 36.0, 2.25 and 1.61 fold higher than at pH 4.0. Imprinted polymer was not selective for oxytetracycline in methanol. However, selectivity in water and acetonitrile was 19.42 and 2.86, respectively. Oxytetracycline did bind to imprinted polymer in water or aqueous buffer (pH 7.0) and could be eluted with methanol. Prepared polymer extracted 75-80 % oxytetracycline from water, honey and egg white.

Objectives: Cefquinome is a fourth generation cephalosporin with broad spectrum antimicrobial activity. It is commonly used against respiratory tract diseases, acute mastitis, calf septicemia and foot rot in livestock. Clean-up step in sample preparation is invariably required for avoiding interferences in assay from other components. It is envisaged to prepare molecular imprinted based polymer with desired selectivity for cefquinome. Method: Imprinted polymer was synthesized over the surface of magnetite using methacrylate (monomer) acid and ethyleneglycoldimethacrylate (crosslinker) in the presence of cefquinome (imprint molecule). Magnetite was prepared by co-precipitation of 1.98 g FeCl 2 .4H 2 O and 5.41 g FeCl 3 .6H 2 O. Magnetic non-imprinted polymer was prepared similarly in absence of cefquinome. Selectivity in different solvent was calculated from partition coefficient values in imprinted and non-imprinted polymers. Result: Selectivity of imprinted polymer over non-imprinted polymer was dependent on nature of solvent and pH. Binding of cefquinome was highly selective in acetonitrile. Imprinted polymer lacks selectivity in methanol and 1M NaCl. Ionic interaction between quinolinium ion in cefquinome and carboxylate anion in polymer appears to be major force for recognition of cefquinome by imprinted polymer. Prepared polymer extracted cefquinome from milk, honey, egg and water and extraction efficiency was in the range of 74-93.7%. Conclusion: Selectivity of magnetic imprinted polymer must be determined in different solvents and this will enable selecting binding and elution conditions during extraction of imprint molecule.