Synthesis Of Imidazole And 4-Methylimidazole Surface Molecularyly Imprinted Polymer And Study Of Its Solid Phase Extraction Performance And Application To Environmental Samples

Molecularly imprinted polymer has the advantages of high selectivity, good stability, simple preparation, and anti-poor environment, etc. And it can eliminate the interference of the complex environmental samples and obtain high recovery. It has been widely used to the pretreatment of environmental samples in the field of solid phase extraction, membrane separation, and chromatography separation.The category of imidazole molecules is a class of heterocyclic aromatic nitrogen compounds. There have a variety of derivatives by chemical reaction due to the weak acid and weak alkaline. In recent years, it has been widely used in the field of pigment and synthesis of ionic liquid. It has been shown that 4-methylimidazole in the pigment can produce ultra-excited state and cause cramps. The alkyl-imidazolium based ionic liquids are toxic to mammalian zooblast, microorganism and among others, and the toxic is just as some conventional organic solvents, and sometimes two-to-four times more toxic than these organic solvents. The wide application of the category of imidazole molecules would inevitably result in the loss of these substances into water ecosystems, leading to pollution of water, soil and ecological environment. Accordingly, it is important to assay trace category of imidazole molecules in environmental samples for the environmental protection and human health.In this paper, two kinds of surface molecularly imprinted polymer were synthesized by using imidazole and 4-methylimidazole as the template and modified silica particles as the support material. The characteristics and its adsorption properties of solid-phase extraction in the water and soil samples were studied. The main results are as follows:1. The studies on the molecular imprinting technique are reviewed, in particular the use of the molecularly imprinted polymer synthesized by different methods and its application in solid phase extraction, membrane separation, chromatography and other environmental samples. In addition, the shortcomings of molecular imprinting technology have been discussed, and then the development of molecularly imprinted technique has been perspected also. Here 157 references were cited.2. Imidazole and 4-methylimidazole surface molecularly imprinted polymers using the modified silica gel as the carrier were prepared by a non-covalent polymerization. To obtain the microstructure information of the new MIP, the MIP-coated silica particles were characterized with UV spectroscopy, FT-IR spectra, SEM micrographs, elemental analysis, and the specific surface area. The physicochemical properties, the parameters of separation and enrichment of MIP, and how MIP reacts with the template molecules were also investigated. What’s more, it is suggested the relationship of the new material between microstructure and the macro-absorption properties to illustrate the selectivity and adsorption capacity to template molecules in complex environmental or biological system.3. The specific adsorption performance of the molecularly imprinted polymers was tested by the adsorption isotherms, kinetic curve, and selective adsorption experments. The results shown the adsorption was fast and the adsorption equilibrium was achieved in 30 min and 40 min, respectively. The binding process could be described by pseudo-second order kinetics. Compared with the corresponding non-imprinted polymer, the molecularly imprinted polymer exhibited much higher adsorption performance and selectivity for template molecules.4. Combined with solid phase extraction technology, the surface imprinted polymers were used as solid-phase extraction column, and the parameters including flow rate of loading, elution solvent and binding capacity of the column were investigated to value the performance of selective seperation. The results of MIP-SPE-HPLC experiments shown the MIP-SPE column could recognize the template molecules from the analogs through specific affinity. Under the optimum conditions, the MIP-SPE-HPLC system was applied to the determination of imidazole and 4-methylimidazole in environmental water and solid samples, and the recoveries of 94% and 99% were obtained for imidazole and 4-methylimidazole, respectively.5. The main results concerned in this paper were summarized, and some new research ideas to sovle the problems of molecularly imprinted technologe in the future work have been put forward.