气相色谱-质谱联用法测定茶叶中17种农药残留

Simultaneous Determination of 17 Pesticide Residues in Tea by GC-MS

建立同时测定茶叶中17种农药残留的气相色谱-质谱(GC-MS)联用方法。茶叶样品经乙腈超声提取,减压浓缩后过Cleanert-Florisil固相萃取柱净化,以正己烷∶乙酸乙酯(1∶1)淋洗。GC-MS采用选择离子监测模式(SIM)进行检测。17种农药在10~1000μg/L浓度范围内呈现良好的线性关系,茶叶样品在500μg/L加标水平下各农药的加标回收率为61.01%~118.27%,相对标准偏差(RSD)为3.3%~11.0%。17种农药残留定量限为0.005~0.02 mg/kg。该方法灵敏、快速、准确、操作简单,可应用于茶叶中多农药残留的测定。

A high performance gas chromatography- mass spectrometry （GC- MS ） method for the simultaneousdetermination of 17 pesticides in tea was developed. The tea samples were ultrasonic extracted with acetonitrile. Afterbeing vacuum-concentrated, the extract was purified by using a Cleanert-Florisil column with n-hexane-ethyl acetate（1 ： 1, V/V） as elution solvent. Acquisition of mass spectrometric data was performed in selected ion monitoring （SIM）mode. The results showed the working curves for 17 pesticides were linear in the range of 10 - 1000 μg/L. The recoveriesof 17 pesticides at spiked level of 500 μg/L were 61.01% -118.27%, and relative standard deviations （RSDs） were3.0% - 11.0%. The limits of quantitation were 0. 005- 0.02 mg/kg. This method is rapid, sensitive and accurate, andit can meet the demands for the determination of multi-pesticides in tea samples.