Studies On The Analysis Methods For Determination Of Organphosphate Pesticide Residues Based On Molecular Imprinting Technology

Organophosphorus pesticides refer to a class of organic compounds containing phosphate esters or thiophosphate pesticides.Because of its variety,high efficacy and wide use,it has become the most widely used type of pesticide in agricultural production in recent years.The use of organophosphorus pesticides can effectively control pests and weeds and improve the production and quality of agricultural products,but the excessive and improper use of organophosphorus pesticides has made the problem of organophosphorous pesticide residues in food varieties increasingly prominent and serious.The residues of organophosphorus pesticides are harmful to public health through the food chain.The excess residue affects the development of import and export trade.The frequent occurrence of organophosphorus pesticide food safety incidents seriously affects the stability of society.In order to effectively control organophosphorous pesticide residues,it is very urgent to develop a fast,efficient and simple method to detect organophosphorous pesticide residues.In this study,two new organophosphorous pesticides based on Molecular imprinting and chromatographic techniques were established.1.Synthesis of molecularly imprinted polymer with trichlorfon as dummy template and establishment of MISPE-GC-MS for detection of three organophosphorus pesticides in foodBased on the characteristics of organophosphorus pesticides,organophosphorus pesticide trichlorfon was selected as a dummyl template molecule.By screening and optimizing the polymer preparation system,three organophosphorus pesticides of parathion,chlorpyrifos and chlorpyrifos were synthesized.The molecularly imprinted polymer was adsorbed and its morphology and adsorption characteristics were characterized.molecularly imprinted solid phase extraction cartridge(MI-SPE)was prepared by using this polymer as solid phase extraction adsorbent.The conditions of MI-SPE were optimized and three organophosphorus pesticides MISPE-GC-MS in corn matrix were established.MS detection method,the recovery rate of three organophosphorus pesticides is between 78% and 101% at the three levels of corn(25,50,100 ?g/kg),and the relative standard deviation is ?15%.(n=3).2.8 organophosphorus pesticides in food tested by MISPE-GC-MS based molecular imprinted polymer using dimethyl thiophosphate as dummy templateIn this experiment,O,O-dimethyl disulfide phosphate Ester is used as template molecule,methacrylate(MAA)is used as function monomer,and ethylene glycol dimethyl acrylate(EDGMA)is used as crosslinking agent.The molecular imprinted polymer with specific adsorption for 8 organophosphorus pesticides was synthesized by optimizing the molecular imprinted polymer system.The results show that the polymer has high specificity,good selectivity and fast adsorption.The polymer is used as solid phase extraction filler and the solid phase extraction conditions are optimized.Finally,a method was established for the detection of 8 organophosphorus pesticides in food by molecular imprinting solid phase extraction and gas chromatography.The standard deviation range for repeated experiments three times in a row is low than 9%.The recovery rate of cucumber was in the range of 70%—114%.3.12 organophosphorus pesticides in food tested by MISPE-GC-MS based on molecular imprinted polymer made of diphenyl chloride as dummy templateA novel imprinted polymer was synthesized from organophosphorus pesticide intermediate chlorodiphenyl phosphate as a template molecular and a Trimethylolpropane trimethacrylate as functional monomer as a crosslinking agent.Adsorption properties of 12species(logo,clozophos,parathion,antiborer pine,chlorpyrifos,hydrolamphos-methyl,rice-rich powder,antipyrethropoxide,pyrethropoxide,propyl bromide,pyrithione s?Lfoxide,ammonia sulfonaphos)were characterized,Based on the molecular imprinting technique and gas chromatography combined with series mass spectrometry,a method for the determination of organophosphorus pesticide residues in food was established.Under optimal conditions,The limit of quantitation(S/N = 10)for 12 organophosphorus pesticides were 20,10,10,5,10,10,5,10,10,5,5,10 ?g/L,respectively.The recovery rate of corn was in the range of66.9%—102%.