分子印迹固相萃取-比率荧光法测定熟地黄中苯并[α]芘的含量

Determination of benzo[α]pyrene in prepared Radix Rehmanniae by molecularly imprinted solid phase extraction coupled with ratio fluorescence detection

目的建立分子印迹固相萃取-比率荧光法,测定中药材熟地黄中苯并[α]芘(BaP)的含量。方法以表面树状功能化接枝的磁性硅胶纳米粒(Fe_(3)O_(4)@SiO_(2)@PAMAM)为载体,BaP为模板分子,采用溶胶-凝胶法制备BaP分子印迹聚合物(BaP-MMIPs)。通过选择性识别吸附,比率荧光法检测,以浓度(C)为横坐标,荧光信号比值(I_(436)/I_(604))为纵坐标,计算回归方程。结果成功合成具有特异识别性能的BaP-MMIPs,应用于熟地黄样品中BaP的高灵敏检测。BaP在0.14~3.0μg/mL范围内线性关系良好。检测限为80 ng/mL,定量限为112.5 ng/mL。回收率为89.5%~106.8%,RSD不大于3.6%。结论所建立分析方法结果准确,选择性高,灵敏度与重现性好,检测成本低,简便快速,可为中药BaP的限量控制提供参考。

Objective To establish a method for benzo[α]pyrene determination in prepared Radix Rehmanniae by molecularly imprinted solid phase extraction coupled with ratio fluorescence detection.Methods The molecularly imprinted polymers(BaP-MMIPs)were prepared by sol-gel method using dendritic-grafting magnetic nanoparticle as the supporting material and benzo[α]pyrene as the template.Benzo[α]pyrene in the prepared sample was separated and enriched by BaPMMIPs as dispersive SPE materials,and was detected by ratio fluorescence determination.The calibration curve was obtained by measuring the fluorescence intensity ratios(I_(436)/I_(604))of benzo[α]pyrene in different concentrations.Results BaP-MMIPs showed remarkable selectivity,high efficiency and stable,which were successful applied as solid phase extraction materials for the trace benzo[α]pyrene determination in prepared Radix Rehmanniae.Good linearity was achieved in range of 0.14~3.0μg/mL.The LOD was 80 ng/mL(S/N=3)and LOQ was 112.5 ng/mL(S/N=10).The average recoveries of benzo[α]pyrene were 89.5%-106.8%with the RSD≤3.6%.Conclusion The method is accurate,selective,high sensitive,reproducible,economical,simple and fast.The research has profound significance for the benzo[α]pyrene monitoring in Traditional Chinese Medicine.