联苯三唑醇磁性分子印迹聚合物的制备及其在食品检测中的应用

Preparation and Application of Magnetic Molecularly Imprinted Polymer for the Detection of Bitertanol in Foods

采用表面印迹技术,以表面接枝硅烷偶联剂KH570的Fe3O4@SiO2微球为磁性载体,联苯三唑醇为模板分子,建立制备联苯三唑醇磁性分子印迹聚合物(magnetic molecularly imprinted polymer,MMIP)的方法。采用红外光谱、透射电子显微镜、磁响应性能测定等方法对优化条件下制备的聚合物进行表征;通过静态吸附实验考察聚合物对模板分子的吸附能力;并以该聚合物作为固相萃取材料,对小米、小麦等样品中的目标物质进行固相萃取,同时使样品得以净化,并采用高效液相色谱法对样品中目标物进行检测。结果表明,制备的核-壳结构联苯三唑醇MMIP对联苯三唑醇和其结构类似物具有分子识别能力,所建检测方法的线性关系好(r≥0.9996),检出限为0.01~0.02μg/mL,平均回收率在87.7%~104.3%之间,相对标准偏差为1.39%~3.46%(n=5)。该MMIP适用于食品中三唑类农药的快速分离和净化,其检测方法能选择性地快速分析食品中三唑类农药残留量。

A magnetic molecularly imprinted polymer(MMIP)was prepared by surface imprinting technology using Fe3O4@SiO2 grafted with the silane coupling agent methacryloxy propyl trimethoxyl silane(KH570)as the magnetic carrier and bitertanol as the template molecule.MMIP prepared under optimized conditions was characterized by infrared spectoscopy,transmission electron microscopy and magnetic measurement.The adsorption properties of the MMIP for bitertanol were evaluated by static adsorption experiments.The MMIP was used as the solid phase extraction(SPE)adsorbent to extract bitertanol from various food samples such as millet and wheat,which was then purified before being detected by high performance liquid chromatography(HPLC).The results indicated that the MMIP,with a core-shell structure,could recognize bitertanol and its structural analogues.The proposed method showed good linearity with correlation coefficient≥0.9996.The limit of detection was 0.01–0.02μg/mL,and the average recoveries were between 87.7%and 104.3%,with relative standard deviations from 1.39%to 3.46%(n=5).The MMIP was suitable for the rapid separation and purification of triazole pesticides from foods,and the developed analytical method could selectively and fast detect triazole pesticide residues in foods.