毒死蜱磁性分子印迹聚合物的制备、表征及其应用

Preparation,Characterization and Application of Magnetic Molecularly Imprinted Polymers for Chlorpyrifos

以毒死蜱为模板分子、磁性二氧化硅为载体、甲基丙烯酸为功能单体、乙二醇二甲基丙烯酸酯为交联剂,制备了毒死蜱磁性分子印迹聚合物(Fe3O4@SiO2-MIPs)微球。通过傅里叶红外变换光谱法、X射线衍射法对其结构进行表征。采用平衡吸附实验和竞争性吸附实验验证印迹聚合物(Fe3O4@SiO2-MIPs)对毒死蜱特异性吸附作用,用Langmuir-Freundlich及Scatchard法对吸附结果进行分析,计算出聚合物对模板分子的饱和吸附量为26.69 mg/g。为进一步验证此磁性印迹聚合物在预处理时的分离净化效果,将其应用于辣椒红色素毒死蜱含量测定的预处理实验中,可看到净化效果明显优于单一盐析法。进而进行该方法的验证实验,测得其回收率为90.89%~93.92%,相对标准偏差为2.65%~3.24%,检出限为7.2μg/kg。

Using chlorpyrifos as template molecule,alpha-methacrylate as functional monomer and ethylene glycol dimethyl acrylate as crosslinking agent,the magnetic molecular imprinted polymer microspheres(Fe3O4@SiO2-MIPs)of chlorpyrifos were prepared.The structures of molecular imprinted polymer were characterized by Fourier transform spectroscopy and X-ray diffraction.The specific adsorption effect of the imprinted polymer(Fe3O4@SiO2-MIPs)on chlorpyrifos was verified by equilibrium adsorption experiment and competitive adsorption experiment.The adsorption results were analyzed by Langmuir-Freundlich and Scatchard method,and the saturated adsorption capacity of the polymer to the template molecule was calculated to be 26.69 mg/g.In order to further verify the separation and purification effect of this magnetically imprinted polymer during pretreatment,it was applied to the pretreatment experiment for the determination of chlorpyrifos in capsaicum red pigment,and the purification effect was obviously better than that of single salting out method.Then the method was verified by experiments,and the recovery was 90.89%~93.92%,the relative standard deviation was 2.65%~3.24%,and the detection limit was 7.2μg/kg.