本文以改性松香(马来松香丙烯酸乙二醇酯)为交联剂,采用表面印迹-悬浮聚合法制备对甲硝唑(MNZ)具有特异选择性的磁性分子印迹聚合物(MMIPs)微粒。首先在以共沉淀法合成的Fe3O4钠米粒子(Fe3O4NPs)表面包裹油酸(OA)形成Fe3O4@OA NPs;然后,以模板分子甲硝唑、功能单体甲基丙烯酸、交联剂改性松香、Fe3O4@OA NPs发生共聚合反应形成MMIPs。通过单因素实验对MMIPs的合成条件进行优化。采用场发射扫描电镜(FESEM)、傅利叶变换红外光谱(FT-IR)、振动样品磁强分析(VSM)、热重分析(TGA)和吸附实验等方法对MMIPs的形态、结构、磁性、热稳定性和分子识别特性等进行表征。结果表明MMIPs的粒径均匀,具有较强热稳定性,快速的磁响应性以及分子识别特异性;在外加磁场作用下,MMIPs可快速将甲硝唑与样品基质分离,大大提高了样品前处理的实验效率。MMIPs作为一种新型固相萃取材料,可以从化妆品样品中选择性分离和富集违规添加的甲硝唑,可应用于化妆品的安全检测。
Novel MMIPs were designed and synthesized by surface-suspension polymerization using ethylene glycol maleic rosinate acrylate( EGMRA) as the cross-linking agent in this study. First,oleic acid( OA) was modified onto the surface of Fe3O4 NPs that were prepared by the co-precipitation. Finally,the MMIP was prepared by suspension polymerization using Fe3O4NPs@ OA as magnetic core,MNZ as the template molecule,methacrylic acid as the functional monomer,and modified rosin as the cross-linking agent. The optimal synthetic conditions were studied by single factor experiment. The morphology,magnetic,thermal stabilization and adsorption selectivity properties of the obtained MMIPs were characterized by field-emission scanning electron microscope( SEM),Fourier transform infrared spectrometer( FT-IR),vibrating sample magnetometer( VSM),thermal gravimetric analyzer( TGA) and re-binding experiments. The results indicated that the MMIPs materials had uniformity particle,stronger thermal stabilization,fast magnetism response and high selective adsorption capacity. The absorbed analytes of MMIPs were quickly separated using an external magnetic field which greatly improved sample pre-treatment efficiency. The MMIPs can be used for the separation and enrichment of trace amounts of MNZ in cosmetic samples.