Study On The Detection Of Pyrethroid Pesticide And Mixed Pesticide Residues In Food By Molecular Imprinting And Related Technologies

Molecular imprinting technology was applied to prepare molecularly imprinted solid phase extraction materials using cyhalothrin or cyhalothrin and bitertanol as the template molecules by bulk polymerization,precipitation polymerization and situ polymerization,and the materials were used to separate and determine pyrethroid insecticides and triazole fungicide residues in foods.Molecularly imprinted solid phase extraction technology had obvious advantages compared with general solid phase extraction technology,such as good separation enrichment effect,strong specificity and repeated use.Background and significance of the research,pyrethroid insecticides and triazole fungicides,molecular imprinting technology and its application were introducted.To prepare effectively pyrethroid insecticides molecularly imprinted polymer,computer simulation technology was used to select template substance,ultraviolet spectroscopy was used to select the optimal functional monomer alpha methylacrylic acid and research the interaction between cyhalothrin and the functional monomer..The feasibility and validity of the ultraviolet spectrometry were verified by Scachard analysis.And the optimal porogen--acetonitrile was chosen by UV spectrometry.A molecularly imprinted solid phase extraction(MISPE)-high performance liquid chromatography(HPLC)– diode array detector(DAD)method was developed for simultaneous determination of six pyrethroid insecticides in food samples.Molecularly imprinted solid phase extraction materials were prepared by bulk polymerization,precipitation polymerization and situ polymerization using cyhalothrin as template molecule,ethylene glycol dimethacrylate(EDMA)as crosslinking agent,?-methacrylic acid(MAA)as functional monomer for pretreatment of the samples,and multi-gradient combination was used to detect the samples.The pretreatment method was simple and fast,and had the strong adsorption capacity for the six pyrethroids and good cleansing effect for samples.Complete sparation of the six pesticides was achieved within 19 min.The separation time was shortened,and the sensitivity was greatly improved.The detection limits were between 0.01 ?g/mL and 0.05 ?g/mL,the average recoveries were82.7%-95.9%,the relative standard deviations were less than 3.83%(n=5).A molecularly imprinted solid phase extraction(MISPE)-high performance liquid chromatography(HPLC)-DAD method was developed for simultaneous determinationof eight pyrethroid insecticides and triazole fungicides in food samples.Molecularly imprinted solid phase extraction materials were prepared by bulk polymerization,precipitation polymerization and situ polymerization using cyhalothrin and bitertanol as template molecule,ethylene glycol dimethacrylate(EDMA)as crosslinking agent,?-methacrylic acid(MAA)as functional monomer to pretreat the samples,and multigradient combination was used to detect the samples.The results showed that the pretreatment method was simple and fast,and had the strong adsorption capacity for the eight pesticides and good cleansing effect for samples;complete sparation of the eight pesticides was achieved within 17 min,the analysis time was short,and the sensitivity was greatly improved,the linear relationship was good(r?0.9987),the detection limits were between 0.01 ?g/mL and 0.05 ?g/mL,the average recoveries were 81.3%-98.5%,the relative standard deviations were less than 4.13%(n=5).A goal was reached that this method of simultaneous separation and detection two category pesticide residues in samples was developed using a di-template molecularly imprinted material by a polymerization.