Synthesis of Lidocaine Molecularly Imprinted Polymers and Application on Solid Phase Extraction

Itaconic acid was selected as the best template for lidocaine molecularly imprinted polymer (MIP) through computational investigation and template-monomer interaction experiment. The MIP was prepared using ethylene glycol dimethacrylate as crosslinker and dimethylformamide as porogen. High retention factor and selectivity were achieved by HPLC evaluation of MIPs as column sorbent. After optimization of SPE profile, it was found that the best imprinting effect was obtained with loading in acetonitrile, washing with methanol-acetonitrile (5:95, V/V), eluting with hydrochloric acid-methanol (5:95, V/V). MIP and nonimprinted polymer (NIP) showed surprisingly high binding capacity in acetonitrile in breakthrough curve, and their capacities are 1.62 and 0.92 mg of drug to 100 mg of adsorbent respectively. Concentration of lidocaine in spiked serum was determined by visible spectrophotometric measurement of the SPE eluent, with the average recovery of 84.6%.