School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Talanta. 2011 Apr 15;84(2):462-70. doi: 10.1016/j.talanta.2011.01.045. Epub 2011 Jan 26.
Novel magnetic molecularly imprinted polymer (MIP) beads using ractopamine as template for use in extraction was developed by microwave heating initiated suspension polymerization. Microwave heating, as an alternative heating source, significantly accelerate the polymerization process. By incorporating magnetic iron oxide, superparamagnetic composite MIP beads with average diameter of 80 μm were obtained. The imprinted beads were then characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and vibrating sample magnetometer. Highly cross-linked porous surface and good magnetic property were observed. The adsorption isotherm modeling was performed by fitting the data to Freundlich isotherm model. The binding sites measured were 3.24 μmol g(-1) and 1.17 μmol g(-1) for the magnetic MIP beads and the corresponding non-imprinted magnetic beads, respectively. Cross-selectivity experiments showed the recognition ability of the magnetic MIP beads to analytes is relative to degree of molecular analogy to the template. Finally, this magnetic MIP bead was successfully used for enrichment of ractopamine, isoxsuprine and fenoterol from ultrasonically extracted solution of pork and pig liver followed by high performance chromatography with fluorescence detection. The proposed method presented good linearity and the detection limits was 0.52-1.04 ng mL(-1).The recoveries were from 82.0% to 90.0% and from 80.4% to 86.8% for the spiked pork and pig liver, respectively, with the RSDs of 5.8-10.0%. Combination of the specific adsorption property of the MIP material and the magnetic separation provided a powerful analytical tool of simplicity, flexibility, and selectivity.
以莱克多巴胺为模板，通过微波加热引发悬浮聚合制备了新型磁性分子印迹聚合物（MIP）微球，用于萃取。微波加热作为替代热源，可显著加速聚合过程。通过引入磁性氧化铁，获得了平均直径为 80μm 的超顺磁复合 MIP 微球。然后通过扫描电子显微镜、傅里叶变换红外光谱、热重分析和振动样品磁强计对印迹珠进行了表征。观察到高度交联的多孔表面和良好的磁性。通过将数据拟合到 Freundlich 等温模型来进行吸附等温线建模。磁性 MIP 珠和相应的非印迹磁性珠的结合位分别为 3.24μmol g(-1)和 1.17μmol g(-1)。交叉选择性实验表明，磁性 MIP 珠对分析物的识别能力与模板的分子类似程度有关。最后，将这种磁性 MIP 珠成功用于从猪肉和猪肝的超声提取溶液中富集莱克多巴胺、异舒普林和特布他林，然后用高效液相色谱法结合荧光检测。该方法具有良好的线性，检测限为 0.52-1.04ng mL(-1)。对于添加的猪肉和猪肝，回收率分别为 82.0%-90.0%和 80.4%-86.8%，相对标准偏差为 5.8%-10.0%。MIP 材料的特异性吸附特性与磁分离相结合，为简便、灵活和选择性提供了强大的分析工具。
