[Spectroscopy study on the selectively distinguishing cefalexin with the molecular imprinted polymer]

Molecular imprinted polymers of cefalexin (CFL) were prepared by non-covalent molecular imprinting technique in the present paper. Using CFL as template molecule, acrylamide (AM) or methacrylic acid (MAA) as functional monomer, ethylene dimethacrylate (EGDMA) as cross-linker, AIBN as initiator and methanol as porogen agent, different molecularly imprinted polymers (MIPs) of CFL were synthesized by bulk or suspension polymerization as synthetic method. The intermolecular action between AM and CFL was investigated by UV and IR spectrophotometric analysis, and the results indicated that polymerizing functional monomer AM could bond effectively with template molecule CFL. By using UV spectrophotometric analysis method, it was found that the MIP prepared with AM-EGDMA by bulk polymerization showed the highest binding capacity for CFL. Test of selective adsorption made clear that the MIP represented more excellent identification property to CFL than to cefadroxol and ampicillin. The MIPs were used as solid-phase extraction sorbent for extraction and enrichment of CFL in actual samples. And the recoveries for CFL extraction were found to be 99.3%-99.7% (n=3), demonstrating the feasibility of the prepared MIPs for CFL extraction.