Dummy-template Molecularly Imprinted Polymer for Selective Solid Phase Extraction of Metronidazole in Bovine Serum

Metronidazole (MNZ) ester was chosen as a dummy template, methacrylic acid as monomer, ethylene glycol dimethacrylate as crosslinker and chloroform as porogen to synthesize dummy-template molecularly imprinted polymers (MIP) for MNZ. The result of batch rebinding tests showed that imprinting factor of the polymer was 2. 02, indicating high recognition ability of the MIP against MNZ. MIP adsorption isotherm was fit to Langmuir adsorption model, therefore it was monolayer adsorption, with maximum binding capacity Q(max) of 116 mu mol/g and binding constant K of 0.65 L/mmol. The recoveries of MNZ on MIP and nonimprinted cartridges were 97. 4% and 44. 3% respectively in solid phase extraction (SPE) experiment. However, the analogues of MNZ, MNZ ester and 4-nitrophenol, had recoveries less than 11. 6% on both MIP and NIP in SPE, showing the high selectivity of the dummy template MIP against MNZ. The MIP was successfully used for the separation and concentration of MNZ spiked serum sample with mean recovery of 94. 5%, which demonstrated that MIP was feasible of pre-treatment of MNZ serum sample without template bleeding.