三聚氰胺磁性表面分子印迹聚合物的制备及其在牛奶样品中的应用

以三聚氰胺（MEL）为模板分子、α-甲基丙烯酸（MAA）为功能单体、乙二醇二甲基丙烯酸酯（EGDMA）为交联剂、Fe₃O₄@SiO₂磁性材料为载体，制备得到三聚氰胺磁性表面分子印迹聚合物（MEL-MMIPs）。分别使用透射电镜（TEM）、热重分析（TGA）、傅立叶变换红外光谱（FT-IR）和振动样品磁强计（VSM）对制备的MMIPs进行表征。结果表明，印迹聚合物层成功地在Fe₃O₄@SiO₂磁性材料表面包覆，印迹粒子具有良好的磁学性能。将磁性分子印迹聚合物应用于牛奶中三聚氰胺的富集分离，采用高效液相色谱法（HPLC）检测，结果显示该磁性表面分子印迹聚合物对三聚氰胺有特异性吸附。以制备的MMIPs为吸附剂，建立了一种简单、快速和高选择性测定牛奶中三聚氰胺的方法。

Preparation of magnetic surface molecularly imprinted polymers for melamine and its application in milk samples

By using melamine (MEL) as the template molecule, magnetic surface molecularly imprinted polymers (MMIPs) were prepared. Methacrylic acid (MAA) was chosen as the functional monomer, and ethyleneglycol dimethacrylate (EGDMA) was chosen as the cross-linker, and Fe₃O₄@SiO₂ was used as the magnetic supporter. Transmission electron microscope (TEM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) analysis and a vibrating sample magnetometer (VSM) were used to characterize the polymers. An imprinted polymer layer was found on the surface of the Fe₃O₄@SiO₂ nanomaterials. MMIPs were applied to extract and enrich melamine in milk samples. The specific recognition capability of the material was confirmed by high performance liquid chromatographic (HPLC) analysis. Thus, a simple and selective method was successfully established using MMIPs as sorbents to detect melamine in milk with satisfactory results.