分子印迹磁性固相萃取/液相色谱法检测奶制品中的双酚A

以双酚A(BPA)为模板分子,磁性二氧化硅(Fe_3O_4@SiO_2)为载体,4-乙烯基吡啶(4-VP)为功能单体,采用表面分子印迹技术制备了双酚A磁性分子印迹聚合物微球(Fe_3O_4@SiO_2-MIPs)。通过红外光谱、透射电镜等对Fe_3O_4@SiO_2-MIPs进行了结构和形貌的表征。将制得的Fe_3O_4@SiO_2-MIPs作为磁性吸附剂,分离富集奶制品中的BPA,建立了分子印迹磁性固相萃取/液相色谱法测定奶制品中BPA的新方法。结果表明,在优化条件下,Fe_3O_4@SiO_2-MIPs对BPA具有良好的选择性,最大吸附容量达13.50 mg/g,在0.05~5.0 mmol/L浓度范围内有良好的线性关系(r2=0.993 4),方法检出限为0.037μg/L,样品加标回收率为86.2%~93.1%,相对标准偏差为2.9%~3.8%。该方法高效快速,选择性好,可用于牛奶样品中痕量BPA的检测。

Determination of Bisphenol A in Milk Sample Using Magnetic Molecularly Imprinted Polymers Solid-phase Extraction Combined with High Performance Liquid Chromatography

A new magnetic molecularly imprinted polymers (MIPs) were prepared by using Fe3 O4@SiO2 as the support,4-vinyl pyridine(4-VP) as functional monomer,bisphenol A(BPA) as template molecule through surface molecularly imprinted polymerization technology.The structure and morphology of Fe3O4@SiO2-MIPs were characterized by infrared spectroscopy (IR)and transmission electron microscopy (TEM).A new method was established for the separation and enrichment of BPA in milk sample by molecularly imprinted magnetic solid-phase extraction combined with high performance liquid chromatography(HPLC) using Fe3O4@SiO2-MIPs as magnetic adsorbent.The results showed that the Fe3O4@SiO2-MIPs has a high selectivity for BPA under the optimized experimental condition,and the adsorption capacity of Fe3O4@SiO2-MIPs was 13.50 mg/g.The calibration curve of BPA was linear in the range of 0.05-5.0 mmol/L with a correlation coefficient (r2) of 0.993 4.The limit of detection(LOD) was as low as 0.037 μg/L.The proposed method was successfully applied in the determination of BPA in milk sample,with average recoveries of 86.2％-93.1％ and relative standard deviations(RSDs) of 2.9％-3.8％ at three spiked levels.The developed method is rapid and selective,and is adaptable to the analysis of trace BPA in milk sample.