Surface Iimprinted Materials Via Surface-Initiated Atom Ttransfer Radical Polymerization And Its Recognition Characters

In this paper the chloromethyl polystyrene (CMCPS) resin and magnetic CMCPS microspheres as carrier and macroinitiator, 2,4-dichlorophenoxyacetic acid (2,4-D), imazethapyr (IM) surface molecularly imprinted polymer materials and lincomycin (Lin) magnetic surface molecularly imprinted polymers were successfully prepared by using surface-initiated atom transfer radical polymerization (SI-ATRP) method. The binding properties and adsorption properties of imprinted materials for the template molecules were studied. The materials were used as solid-phase extraction (SPE) materials coupled with HPLC for the selective extraction and detection of trace amounts of pesticides and veterinary drug residues, and the good results were obtained.The paper mainly includes the following several parts:1、2,4-dichlorophenoxyacetic acid imprinted materials (MIPs) were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) method. The chloromethyl polystyrene resin (CMCPS) as carrier and macroinitiator for the first time, the imprinted polymers were carried out by using 2,4-dichlorophenoxyacetic acid as template, acrylic amide as functional monomer, CuBr/2,2’-bipyridine (Bpy) as the catalytic system. The influence of ratio of template and monomer on the adsorption capacity of 2,4-D MIPs was discussed in details. The binding properties of MIPs for 2,4-dichlorophenoxyacetic acid were studied in details. The results showed that MIPs have specific recognition selectivity and excellent binding selectivity for the template molecule. The reference substance 2,4-dichlorophenol and 2,4-dichlorobenzaldehyde, its selectivity coefficient for 2,4-D are 2.82 and 3.77, the relative selectivity coefficient are 2.33 and 2.30. Qmax values were calculated to be 76.93 mg/g, 142.92 mg/g, respectively, and Kd values were calculated to be 632.90 mg/L, 2309.49 mg/L. MIPs as solid phase extractant, and spiked recovery in bean sprout samples experiment showed that imprinted materials can enrich and separate for trace amounts of 2,4-D, the addition standard recoveries were among 85.7%-104.3%, it is also easy to be used repeatedly.2、The SI-ATRP was performed in methanol-water (4:1, V/V) binary mixed solvents, and obtained the molecularly imprinted polymers of IM. The MIPs were characterized by elemental analysis and scanning electron microscopy. Binding selectivity, adsorption capacity and the reusability for this MIPs were also evaluated in details. Results indicated the prepared MIPs exhibited fast binding ability and high selectivity for imazethapyr, the selectivity coefficients were 4.26. The MIPs were used as solid-phase extraction (SPE) materials coupled with HPLC for the selective extraction and detection of trace imazethapyr from soil sample. Calibration curve was established with R of 0.9995 for concentrations in the range of 0.10-5.00 μg/mL. The obtained results revealed that the extraction recoveries of imazethapyr from real samples were in the range of 91.12-97.49%, the relative standard deviation were 3.71%-6.52%.3、Using REDOX coprecipitation method prepared magnetic Fe3O4, prepared the PCMSs/DVB microsphere via "one step seed swelling" method, and then the surface of PCMS/DVB microsphere coated with the magnetic Fe3O4. The magnetic surface molecularly imprinted materials (MMIPs) were prepared by SI-ATRP. The MMIPs were carried out by using the Fe3O4/PCMS/DVB microspheres as carrier and macroinitiator. The adsorption properties of MMIPs for lincomycin were studied. The experiment results showed that the MMIPs with rapid binding capacity and high selectivity. And the spike recovery was 86.29%-101.2%, and the experiment showed magnetic surface molecularly imprinted materials can enrich and separate for trace amounts of lincomycin in milk sample, this method has a higher recovery rate and it is also easy to be used repeatedly.