共价有机聚合物固相萃取/高效液相色谱法测定面粉中3种荧光增白剂

Analysis of Three Fluorescent Whitening Agents in Flour by High Performance Liquid Chromatography with Covalent Organic Polymers Based Solid Phase Extraction

以三氯化铋为催化剂,使2,4,6-三羟基-1,3,5-苯三甲醛和2,6-二氨基吡啶在低温下快速形成亚胺键,成功制备出具有良好吸附性能的共价有机聚合物。通过傅立叶红外光谱和氮气吸附实验对聚合物进行表征,结果显示,亚胺键合的多孔聚合物已成功合成且具有良好的比表面积。将制备的多孔聚合物用于固相萃取填料,建立了面粉中3种荧光增白剂的高效液相色谱检测方法。方法学验证结果表明,3种荧光增白剂在1～100μg·L-1范围内线性关系良好,检出限(LODs,S/N=3)为0. 15～0. 27μg·kg-1,定量下限(LOQs,S/N=10)为0. 50～0. 89μg·kg-1。在不同加标水平下,方法的平均回收率为81. 2%～102%,相对标准偏差(RSDs)为4. 3%～12. 7%。该方法具有操作简单、准确、灵敏度高的优点,可用于面粉样品的测定。

A method of high performance liquid chromatography with solid phase extraction using covalent organic polymers(COPs)was developed for the analysis of three fluorescent whitening agents(FWAs)in flour.The COPs with satisfactory adsorption performance were successfully synthesized by the Schiff base reaction of 1,3,5-triformylphloroglucinol and 2,6-diaminopyridine at room temperature,using BiCl 3 as catalyst,then characterized by Fourier transform infrared spectroscopy(FT-IR)and nitrogen adsorption experiment.Results showed that the imine linked COPs with good specific surface area were successfully constructed.The synthesized COPs were used as the SPE sorbent in the extraction of three FWAs in flour,and finally the three FWAs were determined by high performance liquid chromatography(HPLC).Under the optimum conditions,the method exhibited good linear relationships for the analytes in the range of 1-100μg·L^-1 with limits of detection(LODs,S/N=3)and limits of quantitation(LOQs,S/N=10)of 0.15-0.27μg·kg^-1 and 0.50-0.89μg·kg^-1,respectively.The recoveries for three FWAs in flour at three spiked levels ranged from 81.2%to 102%with relative standard deviations(RSDs)of 4.3%-12.7%.The developed method was simple,accurate and sensitive,and could be applied in the determination of FWAs in flour samples.