气相色谱－质谱法测定茶叶中唑虫酰胺残留量

建立了茶叶中唑虫酰胺残留量快速测定的气相色谱－质谱法。茶叶中的唑虫酰胺用正己烷－丙酮（7：3， V／V）混合液提取，经石墨化碳黑固相萃取小柱净化，用正己烷－丙酮（9：1， V／V）混合液洗脱，浓缩定容后，用气相色谱－质谱法测定，外标法定量。结果表明，目标物质在0．010～0．500 mg／L范围内的线性关系良好；空白样品在0．010～0．500 mg／L范围三水平加标回收实验中的平均回收率在75．2％～112．8％之间，相对标准偏差（ n＝3）为2．85％～5．12％；方法的定量下限为0．005 mg／kg。该方法操作简单、检测灵敏度高，能满足茶叶中唑虫酰胺残留量的检测需求。

Determination of Tolfenpxrad Residues in Tea by Gas Chromatography Mass Spectrometry

A rapid approach for the determination of tolfenpxrad residues in tea via gas chromatography-mass spectrometry method was developed.Tolfenpxrad residues in tea were firstly extracted with an hexane-acetone （7：3, V/V） mixture, then purified through an Carbon-GCB SPE to remove impurities, and finally cleaned-up with hexane-acetone （9：1, V/V） mixture.After being concentrated and set the volume, the target compounds were analyzed by GC-MS and quantified by the external standard method.The results indicated that the calibration curves were linear in the range of 0.01~0.5 mg/L.Tests of recovery were measured by adding tolfenpxrad standard to a series of blank tea samples to make the final tolfenpxrad concentrations in the range of 0.01~0.5 mg/L.The values of recovery were between 75.2%and 112.8%, with relative standard deviations （RSDs, n=3） within 2.85%~5.12%.The detection limit of this as-developed method was 0.005 mg/kg.Hence, due to its high simplicity, excellent sensitivity, and easy popularization, it was able to meet the detection requirements of tolfenpxrad residues in tea real samples.