The Study On Selective Recognition Of Molecularly Imprinted Composites For Persistent Organic Pollutants

The analysis methods,environmental behavior,toxicity and ecological risk of persistent organic pollutants?POPs?have become a hot topic in the field of environmental science in the last ten years.Because of the complexity of environmental samples matrix,at the same time,there are many interfering substance,which are easily affected by the environment,and the most of pollutants in environmental matrix is trace content.At present,some new sample pretreatment technologies with solvent-free,low-cost and environment-friendly have been developed,such as solid phase microextraction?SPME?and magnetic solid phase extraction?MSPE?.Therefore,it is necessary to develop some new,efficient,time-saving and easy to operate the sample pretreatment technologies to solve these problems.The choice of the adsorption medium?materials?is the key.New adsorption materials have the advantages of low density,large specific surface area,controllable pore size,excellent chemical and physical stability,such as molecularly imprinted polymers?MIPs?,which show the great potential in the field of sample preparation technology.In this thesis,.three kinds of novel molecularly imprinted composite were synthesized and used as adsorption material in MSPE and SPME.To separate and enrich the trace amounts of POPs in different environmental medium,brominated flame retardants?BFRs?,Triclosan and Triclocarban?TCS and TCC?and endocrine disrupting chemicals?EDCs?were analyzed followed by high performance liquid chromatography?HPLC?.It is mainly composed of four chapters:In Chapter 1,the hazards of persistent organic pollutants and several kinds of new sample pretreatment techniq ue were introduced,the superiority of molecularly imprinted materials are demonstrated.Then the development,application field,definition and principle,classification,and preparation methods of molecularly imprinted polymer were summarized simply in the chapter.In Chapter 2,a novel magnetic mesoporous molecularly imprinted polymers with core-shell structure were prepared by simple surface molecular imprinting polymerization using tetrabromobisphenol-S?TBBPS?as the template and Fe3O4 nanoparticles as magnetic cores.A series of characterizations were made to the MMIPs-TBBPS.The resultant MMIPs-TBBPS were successfully applied magnetic solid-phase extraction coupled with HPLC determination of TBBPS in spiked real water samples with the recoveries of 77.8-88.9% and a maximum adsorption capacity of 1626.8 ?g g-1.In Chapter 3,based on surface precipitation polymerization using Triclosan?TCS?as template and Fe3O4 nanoparticles as magnetic cores,we prepared a novel magnetic molecularly imprinted polymers.A series of characterizations were made to the MMIPs-TCS.Finally,the resultant MMIPs-TBBPS were successfully applied magnetic solid-phase extraction coupled with HPLC determination of TCS in spiked real water samples with the recoveries of 89.5%-108.4% and a maximum adsorption capacity of 1955.8 ?g g-1.In Chapter 4,based on the in-situ polymerization method,a glass capillary with an internal diameter of 1mm was used as SPME substrate,a layer of estrone molecularly imprinted polymer was polymerized on inner and outer surfaces of capillary,and it is used as SPME fiber and combined with HPLC to analyze endocrine disrupting chemicals?EDCs?in environmental water samples.The satisfactory recoveries were in the range of 89.5%-108.4%.Because of the polymerization on the surfaces of both inside and outside the capillary,compared to in-tube SPME,the double-layers fiber show excellent selective adsorption ability and has twice as much adsorption capacity as normal fibers.It has the largest adsorption capacity of estrone.The thermal stability of polymer materials is good,the surface is roughness,and the surface area is 153.1 m²g^-1.