Study On The Preparation And Analysis Application Of Dioctyl Phthalate Molecularly Imprinted Ice Gel

Phthalates plasticizers are important endocrine type environmental disruptors,though they are widely used as plasticizers in the production of food packaging materials.Phthalates plasticizers can do harm to human being by infiltrating in food or direct contact with the human body.Cryogel is a kind of elastics,porous gels formed by crosslinking reaction at-20 ?.It is widely used in the field of adsorption,separation and purification of target molecules as well as sample molding because of its large porous structure and good stability.Molecularly imprinted polymers(MIP)has been applied in the detction of trace components in complex samples due to its specific recognition of target molecule.In the present paper,we investigated the establishment of the selective separation and enrichment method of phthalic acid esters by molecular imprinting technology cryogel(MIC)based electrochemical method and high-performance liquid chromatography(HPLC).The main contents are as follows:1.Synthesis and analytical application of Dioctyl Phthalate templated molecularly imprinted cryogelIn this paper,we prepared a loose,macroporous molecularly imprinted cryogel(MIC)via free radical polymerization at-20? with Dioctyl Phthalate(DOP)as template,methyl methacrylate(MMA)as functional monomer,and ethylene glycol two methyl acrylate(EGDMA)as cross-linking agent.The prepared MIC consisted of particles of 400 nm with regular porous structure under scanning electron microscope(SEM).MIC showed specific adsorption to DEHP,and the maximum adsorption capacity for DOP was 18.60 mg/g.The distribution coefficients of DOP are the highest Dibutyl phthalate(DBP)and diethyl phthalate(DEP)as interference analogues.The adsorption capacity of MIC for DOP were 16,92.In the real milk samples,a column of MIC and MIP was prepared.MIC can successfully Dioctyl Phthalate in milk,and the recovery rate of MIC is 89.4?101%,the relative standard deviation 3.1?7.4%.2.Synthesis and analytical application of the core-shell magnetic Dioctyl Phthalate templated magnetic molecularly imprinted cryogelIn this chapter,Fe3O4 was prepared by an environmentally friendly hydrothermal route and SiO2@Fe3O4 was synthesized by the the hydrolytic polymerization of tetraethyl orthosilicate(TEOS)on Fe3O4.We prepared the DOP templated core-shell magnetic molecularly imprinted cryogel(MMIC)by using SiO2@Fe3O4 as the carrier,DOP as template,methyl methacrylate(MMA)as functional monomer,and ethyleneglycol dimethacrylate(EGDMA)as the cross-linking agent initiated with sodium bisulfite and ammonium persulfate.The morpholoy and chemical structure of the obtained MMIC was characterized by transmission electron microscope and fourier transform infrared spectroscopy(FI-IR).SiO2 is successfully attached to the surface of Fe3O4 and modified on the surface of magnetic nanoparticles.The distribution coefficients of DOP are the highest dibutyl phthalate(DBP)and diethyl phthalate(DEP)as interferences The selection coefficients of MIC for DOP were 5.324 and 4.118 respectively.While DOP was determined with HPLC after adsorbed by MMIC from Hamburger wrapping paper,the recovery of DOP was 98,2?100.9%,the limit of detection was 2.5 ng/g,and the relative standard deviation was 3.8-6.1%.3.Preparation and analytical application of Dioctyl Phthalate magnetic molecularly imprinted cryogel electrochemical sensorUsing SiO2@Fe3O4 as the carrier,dioctyl phthalate(DOP)as the template,methyl methacrylate as the functional monomer and ethylene glycol dimethyl acrylate(EGDMA)as crosslinker at-20?.Then we prepared the magnetic molecularly imprinted cryogel based electrochemical sensor(MMIC/GCE)as the glass carbon electrode was modified with MMIC.The chemical structure and morphological characteristics of MMIC/GCE sensor were investigated with fourier transform infrared spectroscopy(FT-IR)and transmission electron microscope(TEM).Then its electrochemical properties were tested via cyclic voltammetry(CV)and differential pulse voltammetry(DPV).The adsorption property of MMIC/GCE sensor for DOP was compared with that for DEP and DBP.Results showed that MMIC/GCE sensor owned a much stronger specific retention and enrichment for DOP than that for DEP and DBP.While MMIC/GCE sensor was used to electrochemically detemine DOP in hamburger paper samples,the detection limit was 1.00×10-15 mol/L with a recovery of 97.3%to 106%.There was a good linear relationship of I-C curve of DOP with a linear correlation coefficient R=0.9976 in the range of 1.00×10-8?1.00×10-15 mol/L.