Synthesis Of Surface Molecularly Imprinted Polymer Of Zearalenone And The Application In Grain Analysis

In this work,the pseudo template technology and surface imprinted technology were employed to prepare three different kinds of materials for adsorption and separation.Coumarin-3-carboxylic acid and warfarin were chosen as the pseudo templates of zearalenone,and 7-acetoxy-4-methylcoumarin was chosen as the pseudo template of aflatoxins.MIL-101?Cr?@MIPs,CPT-MIPs?Co-Pseudo templates-MIPs?and CaCO3@MIPs were synthesized with physical wrapping and chemical grafting as synthetic method and pseudo template and co-pseudo templates technology,metal organic frameworks?MIL-101?Cr?and MIL-101?Cr?-NH2?and CacCO₃ as supporting materials,respectively.A series of characterization were performed and adsorption performances were tested of the synthesized MIL-101?Cr?@MIPs,CPT-MIPs and CaCO3@MIPs.Three materials were used in pretreatment steps of real samples,and three kind of sample pretreatments methods were developed and evaluated which is used for the separation and enrichment of trace mycotoxin from real food samples.Based on the corresponding pretreatment and the detection of high-performance liquid fluorescence detector,trace mycotoxin can be stable and rapidly separated and quantified form food samples with low limit of detection and higher sensitivity.And it was divided to three parts as below:1.MIL-101?Cr?@MIPs was synthesized by in-suite polymerization using MIL-101?Cr?,methacrylate,coumarin-3-carboxylic acid as supporting material,functional monomer,and pseudo template,respectively.MIL-101?Cr?@MIPs has a good adsorption performance,its max adsorption capacities for template was 14.12 mg g^-1 and it can reach adsorption equilibrium with 2 min.MIL-101?Cr?@MIPs column was prepared with MIL-101?Cr?@MIPs and solid-phase extraction,the operation of MIL-101?Cr?@MIPs column were optimized,distilled water and 2.5 mL acetonitrile:H₂O?9:1,V/V?as washing solution and eluent.MIL-101?Cr?@MIPs column can be at least reused 5 times with the recoveries higher than 90%.It was applied in the pretreatment steps of zearalenone in corn,wheat,and rice samples,the limit of detection of the method was 4.16?g kg^-1,2.09?g kg^-1,and 3.34?g kg^-1,respectively,the limit of quantification was 12.5?g kg^-1,6.25?g kg^-1,and 10.0?g kg^-1,respectively,the matrix effects was 1.32,1.10,1.37,respectively.2.Metal-organic framework materials with amino modification,MIL-101?Cr?-NH₂,as supporting material to prepared CPT-MIPs with chemical grafting,co-pseudo templates and precipitation polymerization.Warfarin and 7-acetoxy-4-methylcoumarin were used as the co-pseudo templates for zearalenone and aflatoxins.CPT-MIPs can reach the adsorption equilibrium within 5 min,adsorption capacities for two pseudo templates were 7.45 mg g^-1 and6.57 mg g^-1,respectively.The imprinted factors of CPT-MIPs for zearalenone and 4 kinds of aflatoxins were 1.52,1.24,1.36,1.27,and 1.30,respectively,and the selectivity factors of CPT-MIPs were 1.42,1.38,1.29,1.48,and 1.52,respectively.The optimized CPT-MIPs column were applied in the pretreatment steps for rice samples,and limit of detection for zearalenone and 4kinds of aflatoxins of the method were 2.09?g kg^-1,0.39?g kg^-1,0.39?g kg^-1,0.12?g kg^-1,and 0.12?g kg^-1,limit of quantification were 6.25?g kg^-1,1.2?g kg^-1,1.2?g kg^-1,1.8?g kg^-1,and 1.8?g kg^-1.3.CaCO₃@MIPs was synthesized by precipitation polymerization using CaCO₃ as supporting material and acrylamide as functional monomer.The adsorption performance and adsorption process of CaCO3@MIPs were evaluated and studied.CaCO3@MIPs combined with column-assisted dispersive solid-phase extraction was used for zearalenone pretreatment process in food samples.And the optimized operation was methanol:H₂O?3:7,V/V?and 3 mL acetonitrile as washing solution and eluent,respectively.It was applied in the corn samples,millet samples,and rice samples for zearalenone pretreatment steps,the limit of detection were3.0 ng mL^-1,3.0 ng mL^-1,and 5.0 ng mL^-1,respectively,and the limit of quantification were10.0 ng mL^-1,10.0 ng mL^-1,and 15.0 ng mL^-1,respectively.