The Preparation Of Magnetic Molecularly Imprinted Polymers And Application On Triazoles And More Pesticides Residue Analysis In Food

In this thesis,bitertanol molecularly imprinted polymers(MIPs)were synthesized by precipitation polymerization method.Also bitertanol and mix four template magnetic molecularly imprinted polymers(MMIPs)were prepared on the surface of Fe3O4@Si O2 support by the surface molecular imprinting technique.The optimum MIPs were used in the pretreatment of food samples,and the fast separation and cleansing of the target compounds and samples were realized with satisfactory.In order to solve the shortcomings of bulk polymerization,bitertanol MIPs were prepared by precipitation polymerization method.The adsorption and molecular recognition performances of the imprinted polymers were evaluated by high-performance liquid chromatography(HPLC).The morphological features of the optimum imprinted polymers were characterized by scanning electron microscopy(SEM).The adsorption abilities of the imprinted polymers to the template molecules were further investigated through static adsorption and dynamic curve.The prepared polymers were used as the solid phase extraction adsorbents,and the solid phase extraction(SPE)were carried out to extract the target compounds in different real samples successfully and to cleanse the sample,to detect triazole pesticide in food using HPLC.The results demonstrated that the MIPs with specific recognition for bitertanol have been obtained via precipitation polymerization method;the linear relationship was good(r?0.9996),the detection limits were less than 0.02 ?g/m L,the average recoveries were 87.7%?104.3%,the relative standard deviations were less than 3.46%(n=5).The polymers were suitable as the SPE adsorbents for the separation and cleansing of triazole pesticide residues in the various food samples.A method was developed,that MMIPs of bitertanol were prepared by surface imprinting technology,and in which Fe3O4@Si O2 grafted with KH570 was used as the magnetic support.The optimal polymers were characterized utilizing these methods such as fourier transform infrared spectoscopy(FT-IR),transverse electric and magnetic field(TEM),and magnetic measurement methods.The adsorption properties of the MMIPs for the template molecule bitertanol were evaluated by static adsorption test.The MMIPs prepared under the optimal conditions were used as the SPE adsorbents,and the SPE were carried out to extract the target compounds in the various food samples such as millet,wheat,etc,and to detect the target compounds in food samples using HPLC.The results indicated that the bitertanol MMIPs with core-shell structure were successfully achieved,and bitertanol MMIPs exhibited molecular recognition ability for bitertanol.The average recoveries were 87.3%?102.7%,the relative standard deviations were between 1.39% and 3.46%(n=3).The polymers were suitable for the separation and cleansing of triazole pesticides in food samples.A magnetic molecularly imprinted SPE-HPLC-diode array detector(DAD)method was developed for simultaneous determination of triazole fungicide,pyrethroid insecticide,triazine herbicide and carbamate pesticide residues in food samples.To prepare effectively MMIPs,ultraviolet spectroscopy was used to select the optimal functional monomer alpha methylacrylic acid and to select acetonitrile as optimal porogenic agent.The MMIPs were prepared using mix four pesticides(bitertanol,cyhalothrin,atrazine and carbofuran)as the template.The optimal polymers were characterized utilizing these methods such as FT-IR,TEM,and magnetic measurement methods.The MMIPs prepared under the optimal conditions were used as the SPE adsorbents,and the SPE were carried out to extract and cleanse the four pesticides in the various real samples,and to detect using HPLC.The results showed that the mix four template MMIPs exhibited molecular recognition ability for the four pesticides;complete sparation of the eleven pesticides among the four categories of pesticides were achieved within 11 min,the analysis time was short,and the sensitivity was greatly improved,the linear relationship was good(r?0.9996),the detection limits were between 3 ng/m L and20 ng/m L,the average recoveries were 82.3%?92.8%,the relative standard deviations were less than 3.54%(n=5).A goal was reached that this method of simultaneous separation and detection four category pesticide residues in samples was developed using a four-template molecularly imprinted materials by a polymerization.