| Molecular imprinting technique (MIT) as a novel technology has been developed in the synthesis of molecularly imprinted polymers with specific binding sites of a wide variety of molecules. In recent years it have been attracted great attention, because of molecularly imprinted polymer (MIP) has high strength and high selectivity to analytes as a kind of mimic antibody, and the advantages of simple preparation and recycling reuse of MIP compared with natural antibodies. Presently, using this technique to make various related products such as solid-phase extraction (MI-SPE), chromatographic column and biosensor, these products has effectively detected of veterinary drug and pesticides in the food and the environment.Sulfonylurea pesticide is one of the most widely used herbicides because of its high herbicidal activity, broad-spectrum and low toxicity. Though these pesticides such as chlorsulfuron (CS), monosulfuron (MNS) and thifensulfuron methyl (TFM) have been used at low application rates for weed control in cereals, they are now being detected in the food and the environment because of their high mobility and increasing usage. Current existing pre-treatment methods cannot meet the requirements of rapid detection. Pesticide residues in the extraction and enrichment from the sample have been developing based on the molecular imprinting technology. Due to the mixing sulfonylurea herbicide in actual samples, this paper obtained the class-specific, higher selective molecularly imprinted polymer (MIP) and MIP beads adopting to bulk polymerization and precipitation methods based on sulfonylurea herbicide structure characteristics, and selecting appropriate template molecule, optimizing the ratio of functional monomers and template. In the following experiment, the recognition of MIP to template molecular and its analogues were analyzed by means of ultraviolet spectrum, HPLC, SEM, and FTIR. At the same time, a novel method based on the molecularly imprinted solid-phase extraction (MISPE) procedure has been developed for the simultaneous determination of concentrations of sulfonylurea herbicides by LC–MS/MS. Finally, applying to the MIP as sensitive materials further to study on the preparation methods of chip for SPR sensor.This paper mainly research results and conclusions as followed:(1) The preparation system of molecularly imprinted polymer for chlorsulfuron was developed by precipitation polymerization and bulk polymerization. The class-specific molecularly imprinted polymer (MIP) for 3 kinds of sulfonylurea herbicides was synthesized using chlorsulfuron as the template molecule, choosing and optimizing the ratio between different functional monomer and template by ultraviolet spectrum, as well as analyzing the effect of different cross-linker, the volume of solvent system and polymerization initiator on the property of MIP by HPLC and SEM. this paper developed the preparation program of molecularly imprinted polymer in two different synthesis methods .the bulk polymerization methods for MIP was obtained by using CS as template molecule, DEMA as functional monomer , EGDMA as cross-linking agent (1:4:20,m/m/m),and 2 mL acetonitriles as solution. In precipitation polymerization methods, TRIM as the cross-linking agent and other factors the same as above the bulk polymerization (1:4:4, m/m/m), and 80 mL acetonitrile used. These two kinds of methods for the preparation of other conditions as followed: The solutions were mixed ultrasonically for 10 min, then purged with a stream of nitrogen for 10 min and sealed. The polymerization was initiated by placing the flask in a water bath at 60°C for 24 h. By using HPLC methods analyzed the adsorption performance for MIP and MIP beads, the results showed that the adsorption capacity of MIP is 1200μg/g in the bulk polymerization. And the adsorption capacity of MIP beads for CS is 1400μg/g in the precipitation polymerization. It also showed that the MIP and MIP beads have good adsorption ability to its structure analogues such as MNS and TFM.(2) The recognition mechanism of molecularly imprinted polymer (MIP) to target anlytes was studied by ultraviolet spectrum, infrared spectrum, high performance liquid chromatography (HPLC) and scanning electron microscope and other modern technologies. Analyzing the Scat chard curve, the results showed that the adsorption performance curve has two distinct regions. Carrying on the linear regression, the two regression equations were obtained, this suggested the MIP sites was uneven, and had two kinds of binding sites in MIP. the dissociation constants of high affinity with sites and the biggest combining quantity (Qmax) were 0.083μg/mL and 246.6μg/g, respectively .but the dissociation constants (Kd) and Qmax of low affinity with sites were 0.298μg/mL and 477.7μg/g, respectively .The spectrum of template (CS) and molecularly imprinted polymers, which were after and before absorbed CS, were analyzed by Using FTIR with HATR. The results showed that the carbonyl and methyl groups participated in the interaction of template molecular and molecularly imprinted polymer. In addition, the acylamino groups of sulfonylurea herbicide were likely to play a key role in the formation of hydrogen bonds, and further explained the adsorption of MIP to CS, MNS and TFM.(3) The extraction and purification procedures for the solid-phase extraction (SPE) cartridge with a molecularly imprinted polymer as the adsorbent for the selected sulfonylurea herbicides were then established. A molecularly imprinted solid-phase extraction method followed by high-performance liquid chromatography–tandem mass spectrometry for the determination of chlorsulfuron, monosulfuron, and thifensulfuron methyl was also established. The mean recoveries of these compounds in maize were in the range 75%–110 % and the limits of detection (LOD) of chlorsulfuron, monosulfuron, and thifensulfuron methyl were 0.02μg/kg, 0.75μg/kg and 1.45μg/kg, respectively. It was demonstrated that the MISPE–HPLC–MS/MS method could be applied to the determination of chlorsulfuron, monosulfuron, and thifensulfuron methyl in maize samples.(4) The preliminary study on the property of the surface plasma resonance sensor based on molecularly imprinted polymer membrane chip. The preparation methods of three SPR chips such as the Vinyl group covalent bond, peptides methods and PVC with MIP film copolymerization were developed. The morphology and thickness as well as dynamics absorption of three kinds of SPR chips were studied by homemade SPR sensor and AFM. The results showed that the three MIP-SPR chips produced SPR phenomenon, which could cause the change of SPR Angle; thickness of coating MIP on the chip were controlled in the range from 150 nm to 2μm; these chips showed different adsorption to CS, But SPR chip which was combined with PVC-MIP membrane has better the selectivity and adsorption to target analyte compared with other MIP-SPR chips, and The synthetic method of PVC-MIP chip was simple and easy to operate, as well as the MIP-SPR chip had good regeneration stability. Therefore, in the later study, could use PVC-MIP chip to further study on the linear range and detection limit of the SPR sensor with MIP for CS in real sample, and develop a novel method of the determination of the sulfonylurea pesticide.
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