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采用化学共沉淀法制备Fe3O4磁性纳米粒子,以3-氨丙基三乙氧基硅烷(APTES)对其表面进行氨基硅烷化改性,形成Fe3O4@SiO2-NH2纳米粒子。以其作为磁性核,采用表面印迹技术,以没食子蓝为模板,丙烯酰胺(AM)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,在Fe3O4@SiO2-NH2表面形成没食子蓝分子印迹聚合膜,制备了核-壳型没食子蓝磁性分子印迹聚合物(Fe3O4@MIPs)。分别采用红外光谱(FT-IR)、场发射扫描电镜(FESEM)、振动样品磁强分析(VSM)和热重分析(TGA)等仪器分析手段,对Fe3O4@MIPs的结构进行表征。研究了它对没食子蓝的吸附性能,探讨了吸附动力学、吸附等温线及分子识别性。并将其应用于食品中分离富集没食子蓝。结果表明,所制备的核-壳型磁性分子印迹聚合物具有高吸附容量(表观最大吸附量达149.32 mg/g),快速的结合动力学(60 min达吸附平衡)及显著的吸附选择性(印迹因子达9.10)。以其作为新型固相萃取材料,结合高效液相色谱(HPLC)检测,对加标食品样品中的没食子蓝进行分离、纯化、检测,加标回收率在97.69%~104.4%之间,RSD在0.85%~1.2%之间,检测限为0.0051μg/m L。在外加磁场作用下Fe3O4@MIPs可快速与样品基质分离,大大提高了实验效率。该方法简单快速,可应用于食品中非法添加的没食子蓝的分离检测。
Fe3O4 magnetic nanoparticles were prepared by chemical coprecipitation, and the surface was modified by aminosilylation using 3-aminopropyltriethoxysilane (APTES) to form Fe3O4 @ SiO2-NH2 nanoparticles. The surface morphology of Fe3O4 @ SiO2-NH2 was studied by using the surface imprinting technology, gallic acid as the template, acrylamide (AM) as the functional monomer and ethylene glycol dimethacrylate (EGDMA) The molecularly imprinted polymers were prepared. The core-shell gallo-blue magnetic molecularly imprinted polymers (Fe3O4 @ MIPs) were prepared. The structures of Fe3O4 @ MIPs were characterized by means of FT-IR, FESEM, VSM and TGA. Adsorption properties of gallic acid were studied. Adsorption kinetics, adsorption isotherms and molecular recognition were discussed. And its application in food separation and enrichment gallic blue. The results show that the prepared core-shell magnetic molecularly imprinted polymer has high adsorption capacity (apparent maximum adsorption capacity of 149.32 mg / g), rapid binding kinetics (adsorption equilibrium at 60 min) and significant adsorption selectivity (Blot factor of 9.10). With its new solid phase extraction material, combined with high performance liquid chromatography (HPLC) detection, the spiked blue in the spiked food samples was isolated, purified and detected. The recoveries of spiked samples ranged from 97.69% to 104.4% 0.85% ~ 1.2%, the detection limit of 0.0051μg / m L. Under the applied magnetic field, Fe3O4 @ MIPs can be quickly separated from the sample matrix, greatly improving the experimental efficiency. The method is simple and rapid and can be applied to the separation detection of gallic acid illegally added in food.