食品中核-壳型罗丹明6G磁性分子印迹固相萃取材料的制备及应用

结合磁性分离技术和表面分子印迹技术，以改性Fe3O4为核、罗丹明6G分子印迹聚合物膜为壳，制备核-壳型磁性分子印迹聚合物微纳米材料。研究其对罗丹明6G的吸附性能，探讨了吸附动力学、吸附等温线及分子识别性，并将它应用于食品中分离富集罗丹明6G。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24.69 mg/g）、快速的结合动力学（20 min达吸附平衡）及显著的吸附选择性（印迹因子达4.20）。以其作为新型固相萃取材料，结合高效液相色谱检测，对加标食品样品中的罗丹明6G进行分离、纯化、检测，加标回收率为92.3%～99.2%；相对标准偏差为0.85%～1.12%；检出限为0.003 8 μg/mL。在外加磁场作用下分子印迹聚合物可快速与样品基质分离，提高了实验效率。本方法简单快速，可应用于食品中非法添加的罗丹明6G的分离检测。

Preparation and Adsorption Performance of Core-Shell Magnetic Molecularly Imprinted Polymer Microspheres for Solid Phase Extraction and Detection of Rhodamine 6G in Foods

Core-shell magnetic molecularly imprinted polymer (MIP) nanoparticles (NPs), in which a rhodamine
6G-imprinted layer was coated on modified Fe3O4 NPs, were synthesized by combined techniques of magnetic separation
and surface molecular imprinting. The Fe3O4@MIPs were studied by re-binding experiments, such as adsorption kinetics,
adsorption isotherm, molecular identification, and applied to the separation and enrichment of rhodamine 6G in food
samples. Under the action of additional magnetic field, the polymers could be quickly separated from the sample matrix and
greatly improved the efficiency of experiments. The results showed that the core-shell Fe3O4@MIPs had a fast adsorption
equilibrium, highly improved imprinting capacity and significant selectivity; the recoveries were in the range of 92.3%–
99.2% with relative standard deviation between 0.85% and 1.12%, and the detection limit was 0.003 8 μg/mL (RSN=3). Thus,
the core-shell Fe3O4@MIPs could be used as a solid-phase extraction material to conveniently detect the illegal addition of
rhodamine 6G in food samples.