新型磁性限进分子印迹复合材料的制备及富集性能

采用浸渍热解法制备磁性凹凸棒土(MATP), 以磺胺二甲氧嘧啶(SDM)为模板分子, 4-乙烯基吡啶(4-VP)为功能单体, 采用反相原子转移自由基聚合(RATRP)法在MATP表面包覆印迹聚合物薄膜, 得到磁性分子印迹聚合物(MATP-MIPs), 最后在MATP-MIPs表面接枝亲水性单体甲基丙烯酸羟乙酯(HEMA), 得到新型磁性限进分子印迹复合材料(MATP-RAM-MIPs). 采用傅里叶变换红外光谱(FTIR)仪、 扫描电子显微镜(SEM)、 热重分析(TGA)仪、 振动样品磁强计(VSM)和X射线衍射(XRD)仪对材料进行了表征. 通过静态水接触角和考马斯亮蓝G-250方法证明材料外表面具有良好的亲水性和排阻蛋白的特性; 采用静态和选择性吸附实验证实MATP-RAM-MIPs对SDM具有良好的吸附选择性和较高的吸附容量. 将该材料直接用于牛血清中磺胺类药物的富集分离, 加标回收率为86.2%~100.6%, 相对标准偏差为2.1%~4.2%, 可见该材料在复杂样品前处理中具有良好的实际应用价值.

Preparation and Enrichment Properties of Novel Magnetic Restricted Access Media-molecularly Imprinted Composites†

The magnetic attapulgite(MATP) was preparrd by pyrolysis method. Then, using sulfadimethoxine(SDM) as template molecule, 4-vinylpyridine(4-VP) as functional monomer, the imprinted layer was coated on the surface of modified MATP via reverse atom transfer radical polymerization(RATRP), getting magnetic molecularly imprinted polymers(MATP-MIPs). Finally, novel magnetic restricted access media-molecularly imprinted composites(MATP-RAM-MIPs) was obtained by grafting hydrophilic monomer hydroxyethyl methacrylate(HEMA) onto the surface of MATP-MIPs. The polymer was characterized by means of Fourier transform infrared(FTIR) spectrum, scanning electron microscope(SEM), thermogravimetric analysis(TGA), vibrating sample magnetometer(VSM) and X-ray diffraction(XRD). The hydrophilicity of MATP-RAM-MIPs and the ability of exclusion of proteins were studied by the water contact angle and Coomassie brilliant blue G-250 method. The adsorption characters of MATP-RAM-MIPs on SDM were studied by adsorption isothermal and selectivity in detail, and MATP-RAM-MIPs were used as solid phase extraction packing to separate and enrichment of SAs from bovine samples. The spiked recoveries were 86.2%—100.6%, and the relative standard deviations(RSD) were 2.1%—4.2%, indicating that this material has application value in the pretreatment of complex samples.