ABSTRACT

In this study, a novel sorbent, 1-octyl-3-methylimidazolium hexafluorophosphate functionalised magnetic poly β-cyclodextrin, was successfully synthesised and applied to magnetic solid-phase extraction for the determination of pyrethroids in tea infusions. The sorbent was characterised by transmission electron microscopy, energy-dispersive spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, vibrating sample magnetometer and Brunauer–Emmett–Teller measurement. All factors affecting extraction efficiency, such as sorbent amount, extraction time, ionic strength and desorption conditions, were optimised individually. Under the chosen conditions, wide linearity (2.5–500 μg L⁻¹) with determination coefficients ranging from 0.9995 to 0.9999, low limits of detection of 0.32–0.54 μg L⁻¹ and good precision (intra-day: 2.6–7.0%; inter-day: 3.5–7.6%) were achieved for four pyrethroids in tea infusions. The relative recoveries of target analytes in real tea infusion samples were from 70% to 101% with relative standard deviations lower than 9.1%. We conclude that the proposed method is promising in the detection of pyrethroids in tea infusions.

摘要

在本研究中，成功​​合成了一种新型吸附剂 1-辛基-3-甲基咪唑鎓六氟磷酸盐功能化的磁性聚 β-环糊精，并将其应用于磁性固相萃取以测定茶浸液中的拟除虫菊酯。通过透射电子显微镜、能量色散光谱、傅里叶变换红外光谱、X 射线光电子能谱、振动样品磁强计和 Brunauer-Emmett-Teller 测量对吸附剂进行表征。影响萃取效率的所有因素，如吸附剂用量、萃取时间、离子强度和解吸条件，都经过单独优化。在所选条件下，宽线性（2.5–500 μg L ^-1) 的测定系数范围为 0.9995 至 0.9999，4 种拟除虫菊酯的检测限为 0.32-0.54 μg L ^-1且精密度良好（日内：2.6-7.0%；日间：3.5-7.6%）茶输液。实际茶浸液样品中目标分析物的相对回收率为 70% 至 101%，相对标准偏差低于 9.1%。我们得出结论，所提出的方法在检测茶浸液中的拟除虫菊酯方面很有前景。