气相色谱-质谱法测定茶叶中42种残留农药

粉碎后的茶叶使用乙腈超声提取，再经石墨化碳固相萃取柱净化，采用气相色谱-质谱法(GC-MS)的选择离子监测（SIM）方式和外标法定量方法，同时分析测定了茶叶中的42种农药(12种有机氯、9种拟除虫菊酯、20种有机磷和戊唑醇)残留量。该方法回收率在62.5%～120.1%之间，相对标准偏差小于15.1%，42种农药的检出限最低为0.3μg/kg，最高为9.2μg/kg。该方法快速、灵敏、准确，各项技术指标满足国内外农药残留检测的要求，能够应用于茶叶试样中痕量农药残留的分析。

Multi-residue determination of 42 pesticides in tea by gas chromatography-mass spectrometry

A method for the determination of 42 pesticide(12 organochlorines,9 pyrethroids,20 organophosphorus compounds and tebuconazole) residues in tea by gas chromatography-mass spectrometry is described.Pesticides were extracted from tea with acetonitrile in an ultrasonic bath and purified on a graphitised carbon black column,and then determined by gas chromatography with electron ionization mass spectrometric detection in the selected ion monitoring mode.When the contamination level was in the range 0.01-0.8 mg/kg,the recoveries ranged from 62.5% to 120.1% with the relative standard deviation from 0.7% to 15.1% for the different pesticides.The detection limit of the method was estimated to be 0.0003-06.0092 mg/kg.The method was shown to be linear over the range assayed,0.004-20 mg/kg,with determination coefficients >0.992.