Study On Adsorption And Extraction Performance Of Molecularly Imprinted Materials Based On Template And Dummy Template

In this paper,molecular imprinting technology and dummy template molecular imprinting technology were compared from the aspects of the mechanism,preparation methods,advantages and disadvantages.Then two typical substances threatening human health were selected as target analytes: plasticizers and organophosphorus pesticides.Dioctyl phthalate molecularly imprinted polymers and chlorodiphenyl phosphate dummy template molecularly imprinted polymers were prepared with dioctyl phthalate and chlorodiphenyl phosphate as templates,respectively.The prepared materials were characterized,and a new configuration for the determination of plasticizers and organophosphorus pesticides by solid-phase extraction gas chromatography-mass spectrometry based on molecularly imprinted polymers was established.The method was evaluated and successfully applied to the determination of plasticizers and organophosphorus pesticides in actual samples.(1)Molecularly imprinted polymers were synthesized using CG161 M as the carrier,dioctyl phthalate as template molecules,methacrylic acid as functional monomer,tetraethyl orthosilicate as the crosslinking agent by sol-gel method,and nonimprinted polymers(NIPs)were synthesized under the same conditions without template molecules.(2)The synthesized materials were characterized by Fourier transform infrared spectroscopy,scanning electron microscopy,thermogravimetric analyzer and nitrogen adsorption desorption instrument.The characterization results showed that the surface of the CG161 M sphere was successfully covered with molecularly imprinted polymers films.(3)Dimethyl phthalate,diethyl phthalate,dibutyl phthalate,and dioctyl phthalate were selected as templates to prepare molecularly imprinted polymers,and the adsorption effects were compared.The results showed that the molecularly imprinted polymer with dioctyl phthalate as a template had the best adsorption effect on the target analyte.It could be concluded that the template molecules with a large steric effect could leave larger cavities in the polymer and adsorb more template analytes.According to this conclusion,diphenyl chlorophosphate was selected as the dummy template to prepare the dummy template molecularly imprinted polymer to adsorb the target analyte organophosphorus pesticides.(4)The best adsorption conditions were selected to add standards to the actual samples,and the recovery was calculated.Combined with MIPS solid-phase extraction gas chromatography-mass spectrometry,a method for the analysis and detection of three phthalate esters in the solution was established.The method was applied to the analysis of PAEs in milk,soybean milk,coffee,and Huoxiang Zhengqi water,and the recovery was good.(5)According to the template comparison conclusion in the previous chapter.diphenyl chlorophosphate was selected as the dummy template to prepare the dummy molecularly imprinted polymer.A method for the analysis and detection of five organophosphorus pesticides in the solution was established.The method was applied to the analysis and detection of organophosphorus pesticides in actual samples such as milk,soybean milk,coffee,and Huoxiang Zhengqi water.The recovery rate was good.In this paper,a new method for the detection of plasticizer and organophosphorus pesticides in actual samples was successfully established.The experimental conditions were mild,the experimental operation was simple,and had the advantages of high recovery,low detection limit,and fast detection speed.It had high research value and far-reaching application prospects.