Study On The Preparation And Application Of Triazine Herbicide And Three Categories Of Pesticides Molecular Imprinted Solid Phase Extraction Materials

Molecular imprinting technology was applied to prepare molecularly imprinted solid phase extraction materials using one or more categories of pesticides as the template molecules by precipitation polymerization,suspension polymerization and situ polymerization,and the materials were used to separate and determine triazole fungicides,pyrethroid insecticides and triazine herbicides 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.To prepare effectively atrazine molecularly imprinted polymer,ultraviolet spectroscopy was used to select the optimal functional monomer ?-methacrylic acid(MAA)and research the interaction between atrazine and the functional monomer.The feasibility and validity of the method were verified by Scachard method.And acetonitrile as the optimal porogenic agent was selected by ultraviolet spectrum analysis.Molecularly imprinted solid phase extraction column were prepared by precipitation polymerization using atrazine as template molecule,ethylene glycol dimethacrylate(EDMA)as crosslinking agent,MAA as functional monomer for pretreatment of the food samples,and samples were separated and detected by high performance liquid chromatography.The pretreatment method was simple and fast,and had the strong adsorption capacity for triazines and good cleansing effect for samples.Complete sparation of the four pesticides was achieved within 5 min.The detection limits were between 0.5 ng/m L and 5.0 ng/m L,the average recoveries were 86.5%-93.9%,the relative standard deviations were less than3.10%(n=5).In order to solve the worse adsorption problem of polymers in water medium,atrazine molecular imprinting polymers(AMIP)were preparated based on suspension polymerization.The influence factors on the adsorption perpormance were studied,such as the dispersant and its dosage,the amount of acetonitrile and oscillatory speed.Under the optimum conditions,the performances of polymers were characterized by static adsorption test,Scachard analysis and scanning electron microscope.AMIP of high binding ability to the template was obtained by using 1.5% poly vinyl alcoho(PVA)as dispersant,12 m L acetonitrile and 150 r/min oscillatory speed.The results showed that the imprinting polymers had high sensitivity to the atrazine.Finally,the molecularly imprinted solid phase extraction column was successfully applied to detection of triazine pesticide residues in foods,the average recoveries were 86.4%-99.3%,the relative standard deviations(RSD)were between 1.49% and 3.79%(n=5).A molecularly imprinted solid phase extraction-high performance liquid chromatography-diode array detector method was developed for simultaneous determination of triazole fungicides,pyrethroid insecticides and triazine herbicides in food samples.Molecularly imprinted solid phase extraction materials were prepared by precipitation polymerization,suspension polymerization and situ polymerization using bitertanol,cyhalothrin and atrazine as mixed three template molecules,ethylene glycol dimethacrylate(EDMA)as crosslinking agent,?-methacrylic acid(MAA)as functional monomer,and the materials were used to pretreat the samples.The results showed that the pretreatment method was simple and fast,and had the strong adsorption capacity for the categories pesticides and good cleansing effect for samples;complete sparation of the nine pesticides among the categories pesticides were achieved within 10 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 0.2 ng/m L and 20 ng/m L,the average recoveries were 80.5%-99.7%,the relative standard deviations were less than 4.11%(n=5).A goal was reached that this method of simultaneous separation and detection three category pesticide residues in samples was developed using a three-template molecularly imprinted materials by a polymerization.