Synthesis And Evaluation Of Surface Molecular Imprinted Solid Phase Extraction Materials

Surface molecular imprinting technique is a n emerging molecular recognition technology,which has been applied in solid phase extraction,chromatographic separation,biosensors and membrane separation.To investigate the mechanism of molecular imprinting and recognition and develop new carriers and materials for molecular imprinting technique,this thesis was mainly carried on the following several aspects:To address the problems of roxithromycin（ROX）separation and enrichment in solid-phase extraction,RO X molecule imprinted silicone（ROX-MIP-PMAA/SiO₂）was prepared by surface polymerization method using silicone as the carrier,methyl methacrylate as the functional monomer,ethylene glycol dimethacrylate（EDMA）as the crosslinker.Its adsorption property was studied in detail.Then,the preparation conditions of RO X-MIP-PMAA/SiO₂ were optimized.There were two kinds of interaction sites on ROX-MIP-PMAA/SiO₂,which had larger adsorption capacity and shorter timeto achieve equilibrium than NIP-PMAA/SiO₂.Besides,ROX-MIP-PMAA/SiO₂ also exhibited a good regenerability and reusability.To obtain a better separation selectivity,molecular imprinting technique was applied in lysozyme separation.Polylactic acid（PLA）synthesized by melt polycondensation was modified with hexanediamine.Then,the modified polylactide（DPLA）microspheres were obtained through O/W emulsion solvent evaporation method.Finally,the lysozyme imprinted DPLA microsphere（LZY-MIP-DPLA）was prepared by sol-gel method using DPLA microsphere as the carrier,lysozyme as the template molecule.The equilibrium adsorption measurement showed that LZY-MIP-DPLA had a larger adsorption capacitiy for lysozyme than NIP-DPLA,and there were two kinds of binding sites on LZY-MIP-DPLA.Investigation of adsorption conditions showed that both pH and the concentration of NaCl in solution had remarkable influences on the adsorption properties of LZY-MIP-DPLA.With the deep understanding about the toxicity of phthalate plasticizers,its detection and treatment become an important research subject.Although the macroporous resin has a lot of advantages,it lacks the selective adsorption property.We combined the molecular imprinting technique with the macroporous resin and prepared dioctyl phthalate imprinted D101 resin（DOP-MIP-D101）by using DOP as the template molecule.Static adsorption isotherms showed that the adsorption process of DOP on DOP-MIP-D101 was in agreement with Freundlich model.Adsorption dynamics experiments indicated that Lagergren pseudo-second-order equation could characterize this adsorption process well.In comparison with D101,the adsorption capacity of DOP-MIP-D101 was lower.However,DOP-MIP-D101 had a high recognition ability to DOP as well as a good reusability.