氯氨吡啶酸磁性分子印迹聚合物的制备及识别机理

Preparation and recognition mechanism of aminopyralid magnetic molecularly imprinted polymer

通过合成表面功能化修饰氨基磁性载体,以虚拟模板氨氯吡啶酸为模板分子,4-乙烯基吡啶(4-VP)为功能单体,三羟甲基丙烷三甲基丙烯酸酯(TRIM)为交联剂,甲醇为致孔剂,在磁纳米分子表面制备了氯氨吡啶酸磁性分子印迹聚合物。利用静态吸附、动态吸附和选择性吸附实验考察其吸附性能。利用红外光谱(FTIR)、透射电镜(TEM)、震动样品磁强力计(VSM)等对聚合物进行表征分析,研究聚合物的结合性能和识别机理,并对聚合物的选择性进行了评价。结果表明,该磁性分子印迹聚合物对吡啶羧酸类药物有类特异性吸附,吸附量都达到80. 0%,印迹因子IF> 1。Scatchard方程研究表明有两类结合位点,最大表观结合量分别为2737. 74μg/g和4226. 55μg/g。推测识别机理可能是静电作用力为主。该类聚合物有望作为前处理材料应用于动物源性食品中吡啶羧酸类药物的分离、富集及检测。

The aminopyralid magnetic molecularly imprinted polymer was prepared on the surface of the magnetic nanoparticle using functionalized magnetic silicon modified amino groups as the carrier, picloram as dummy template, 4-vinylpyridine ( 4-VP ) as functional monomer, trimethylolpropane trimethacrylate ( TRIM ) as cross-linker, methanol as porogen. The adsorption properties were investigated by static adsorption, dynamic adsorption and selective adsorption experiments. The polymer was characterized by infrared spectroscopy ( FTIR ), transmission electron microscopy (TEM), and vibrating sample magnetic strength meter ( VSM) to study the bonding and recognition mechanism of the polymer. The selectivity of MMIP was evaluated. The results showed that the magnetic molecularly imprinted polymer had specific adsorption to pyridine carboxylic acid herbicide, and the adsorption amount reached to 80%, with the imprinting factor IF larger than 1. Scatchard equation studies showed that there were two types of binding sites, the maximum apparent binding amount were 2737. 74μg/g and 4223. 55 μg/g, respectively. It is speculated that the recognition mechanism may be dominated by electrostatic interaction forces. The results showed that the prepared materials had specific adsorption to pyridine carboxylic acid herbicide, and it is expected to be used as a pretreatment method for the separation, enrichment and detection of pyridine carboxylic acid herbicide in animal-derived foods.