Synthesis Of Magnetic Molecularly Imprinted Polymers And Analysis Of The Plasticizer In Edible Oil

In this paper, magnetic molecularly imprinted polymers(MMIPs) were prepared by suspension polymerization, using dioctyl phthalate and phthalic acid butyl benzyl ester as template. The reaction conditions were optimized by the single factor experiment and orthogonal experiment. The structure of polymer was characterized via electron microscope scanning, infrared spectrum, etc. The selection and adsorption properties were also studied. The prepared molecularly imprinted polymer microspheres were applied as the magnetic adsorbent to separate and enrich the phthalic acid esters in edible oil before processing. Detailed content of this research were listed as follows:Molecularly imprinted polymer microspheres with selective adsorption ability of phthalic acid esters plasticizer were synthesized by suspension polymerization, using dioctyl phthalate as template molecule, alpha methylacrylic acid(α-MAA) as functional monomer, ethylene glycol dimethyl acrylate(EDMA) as crosslinking agent, azodiisobutyronitrile(AIBN) as initiator. Through a series of single factor experiment and orthogonal experiment, the optimum polymerization condition was obtained. The optimal mole ratio of template, functional monomer and crosslinking agent was 1:6:30while the initiator was 2.5%. The reaction was carried out for 8 h at 70℃. The molecularly imprinted polymer microspheres were used as magnetic solid phase extraction material for selective separation and enrichment of phthalic acid esters plasticizer in edible oil. An analytical method was established. It turned out to be thatthe minimum detection limit was 1μg m L-1~150μg m L-1 and the linear range was 0.010μg m L-1~0.025μg m L-1. The level standard addition recovery rate of 1μg m L-1, 2.5μg m L-1 and 5μg m L-1 were the main scope by tested, and the recovery of oil samples were90.8%~103.4%, 88.5%~92.3%and 80.6%~91.5%. The range of relative standard deviation was 2.32%~5.43%,3.23%~7.02%, 3.21%~6.91% after determing for six times, respectively.Another phthalic acid esters plasticizer-selective magnetic molecularly imprinted polymer microspheres were prepared by suspension polymerization method using phthalic acid butyl benzyl ester as a template, α-MAAand STas mixed functional monomer, AIBN as initiator, EDMA as crosslinking agent. The molar ratio of templates, mixed functional monomer and crosslinking agent was 1:6:20, while that of styrene and alpha methylacrylic acid was 3:4. Initiator was set as 3.5%, and the polymerization was performed at 75℃for 8h. The optimal molecularly imprinted polymers(MIPs) were applied as solid phase extraction column magnetic filler of the SPE column. Selective separation and enrichment of phthalic acid esters plasticizer in edible oil was subsequently processed. The linear range was 1μg m L-1~150μg m L-1and the detection limit range was 0.010μg m L-1~0.025μg m L-1. The level standard addition recovery rate of 1μg m L-1, 5μg m L-1 and 10μg m L-1 were the main scope by tested, and the recovery of oil samples were85.4%~102.3%,82.5%~102.2%and 81.6%~101.8%. The range of relative standard deviation that was determined for six times was 3.25%~10.92%, 4. 32%~10.06%, 5. 57%~12.02%, respectively.