Preparation Of Magnetically Bound Surface Molecularly Imprinted Polymer Based On SI-ATRP Its Adsorption Properties For Several Antibiotics

Restricted In this paper,the monodisperse chloromethylstyrene microspheres(P_CMS-DVB)synthesized by the research group and the magnetic silica microspheres after bromination were used as carriers.In the experimental study,the drugs commonly found in the foods we tested were used.The residual antibiotics were template molecules,and three imprinted polymers were successfully prepared and their adsorption properties for several antibiotics were investigated.The imprinted polymer was tested.And achieved satisfactoryresults.The main contents of themain work of the thesis are as follows:1.Preparation of monodisperse magnetic restricted surface molecularly imprinted polymer and its recognition of tyhiamphenicol in milkIn this experiment,the prepared monodisperse magnetic microspheres?tetravinylbenzyl chloride/divinylbenzene?(Fe₃O₄/P_CMS/DVB)were used as the carrier,and Thiamphenicol?TAP?was used as the target molecule for the experimental study.The 4-vinylpyridine?4-VP?reagent was used as the functional monomer of the experiment,and the polymer was successfully prepared by the surface atom transfer radical polymerization method?SI-ATRP?.TAP remains a monodisperse limited-entry magnetic surface molecularly imprinted polymer?TAP-RAM-MMIPs?with recognition specificity.And the prepared magnetic ferroferric oxide?Fe₃O₄?magnetic nanoparticles were successfully grafted into the interior of the polymer microspheres(P_CMS/DVB)?by expansion adsorption method?,wherein the polymer was swollen by using chloroform When the pores of the microspheres are enlarged,the magnetic nanoparticles of ferroferric oxide can successfully enter the microspheres.With the reaction of time,the pore size of the polymer microspheres will return to the previous particle size,thereby making the ferroferric oxide nanometer.The particles are blocked inside the polymer.Characterization analysis was performed using some instruments:scanning electron microscopy?SEM?,X-ray diffraction analysis?XRD?,multi-element integration analysis?EA?,and vibrating sample magnetometer analysis?VSM?.The results showed that the molecularly imprinted polymer had a good ability to specifically recognize antibiotic residues?TAP?,and the molecularly imprinted polymer reached equilibrium within 100 min through the adsorption equilibrium experiment.The polymer was combined with high performance hydrophobic liquid chromatography?HPLC?.The separation ability of molecularly imprinted specific recognition of the polymer was determined.Through experiments and calculations,the recovery rate of 96.5¹01.1%and the relative standard deviation of 2.8%³.8%indicate that the material has certainapplication value in complex sample pretreatment.2.Specific recognition of sulfonamide in milk by molecularly imprinted materials with magnetic limiting surfaceIn this experiment,the brominated magnetic silica microspheres were used as the carrier?the outer layer of silica coated with ferroferric oxide?Fe₃O₄/SiO₂??,the cuprous bromide?CuBr?and 2,2'-bipyridine?Bpy?formed a catalytic system for the experiment.The functional monomer and template molecules were acrylamide?AM?and sulfamethine pyrimidine?SMR?respectively.The system was successfully initiated by surface atom transfer radical polymerization?SI-ATRP?.A magnetically limited sulfamethazine surface molecularly imprinted polymer?SMR-RAM-MMIPs?was obtained.The experiment was carried out using a Fourier transform infrared spectroscopy?FT-IR?instrument,an elemental analysis?EA?instrument,a thermogravimetric analyzer?TGA?,and a scanning electron microscope analyzer?SEM?.Through the characterization and experimental detection of the performance of sulfamethazine-imprinted polymer,the final experimental results:the concentration of the solution becomes larger and the temperature increases,so that the adsorption amount of the polymer also begins to increase,which is measured by experiments.The adsorption effect was best at the optimum concentration of the polymer?160 mL/L?,and the saturated adsorption capacity?23.83 mg/g?of the static test of the polymer material was also obtained.And using the Scatchard equation to fit the data,showing good fit.Three antibiotic residues similar to those of sulfamethazine were selected in the experiment?sulfamethoxazole?SIZ?,sulfamethiopyrimidine?SDM?,trimethoprim?TMP??as the experiment.In the target competitor,the imprinted polymer was applied to the milk sample to detect SMR by HPLC,and the polymer was found to have a good effect.The recoveries of the spiked standard were 81.1%¹02.7%,the relative standard deviation of 2.6%³.7%,and the better detection limitwas 8.01?g/L.The effect is satisfactory.3.Preparation of molecularly imprinted material with bifunctional monomer method magnetic limiting surface and study on adsorption properties of thiamphenicol in milkUsing surface initiated atom transfer radical polymerization?SI-ATRP?,magnetic ferroferric oxide was coated on silica and used as experimental magnetic carrier polymer?Fe₃O₄@SiO₂?with antibiotic thiamphenicol.?TAP?as the target molecule?template?,the crosslinking agent uses ethylene glycol dimethacrylate?EDMA?,2,2-azobisisobutyronitrile?AIBN?as the initiator,acrylamide?AM?and Both?-methacrylic acid?MAA?,as a bifunctional monomer in this experiment,finally produced a imprinted polymer?TAP-RAM-MMIPS?that specifically recognized antibiotic residues?TAP?.In the experiment,the polymer was characterized by transmission electron microscopy?TEM?instrument,Fourier transform infrared spectroscopy?FT-IR?,thermogravimetric analysis?TGA?and vibrating sample magnetometer?VSM?.The final results showed that the polymer layer was successfully imprinted on the outer layer of the magnetic silica microspheres,and the molecularly imprinted polymer was confirmed to have better magnetic properties.RAM-MMIPS was used to extract and quantify TAP in milk samples.The specificity of the polymer was confirmed by high performance liquid chromatography?HPLC?analysis,and the detection limit?9.6 ug/L?was determined,and the recovery was greater than 90%.Thereby a rapid and selective adsorption method is formed.The imprinted polymer material was tested for the TAP content in the milk sample,and the test results were satisfactory...