Convenient solid phase extraction of cephalosporins in milk using a molecularly imprinted polymer

In this paper, a molecularly imprinted polymer (MIP) for cephalosporin molecules (cephalexin (CFL) and cephapirin (CFP)), was prepared by non covalent molecular imprinting approach and applied to solid phase extraction (SPE). For MIP synthesis, a tributylammonium cefadroxil salt (TBA–CFD) was used as template with methacrylic acid and ethylene glycol dimethacrylate as monomer and cross-linker, respectively, in acetone–methanol 92/8 (v/v) mixture. The selectivity of MIP versus non imprinted polymer (NIP) was confirmed for CFL, CFD and CFP in standard solutions as well as in milk samples. The efficiency of the synthesized MIP was evaluated by means of the application of the proposed MIP–SPE procedure to spiked milk samples previous to the HPLC method for the detection of cephalosporins. The MIP–SPE recoveries were higher than 60% for the three target analytes in spiked milk.