气相色谱-质谱法测定茶叶中12种农药残留的方法

用气相色谱-质谱仪研究同时测定茶叶中12种农药残留的测定方法。分析样品经粉碎、浸泡，用丙酮-正己烷(1：4，V／V)AA，经活性炭柱和弗罗里硅土柱净化，乙醚-丙酮-正己烷(4：4：2，V／V／V)洗脱后，以环氧七氯为内标，GC／MS测定。经过对茶叶加标的回收实验，证实具有快速灵敏简便的优点，适用于多种农药残留分析。其平均回收率在75%-110％，变异系数下于21％，最低检测限为0．01-0．5mg／kg。

DETERMINATION OF 12 PESTICIDE RESIDUES IN TEA BY GC/MS

This paper describes a method for the determination of 12 pesticide residues in tea by capillary gas chromatography-mass spectrometry. It also can make confirmation and quantitation. The pesticides were extracted from the tea sample with a mixed solvent of acetone-hexane(1;4,V/V),cleaned up on active carbon and Florisil with ether-acetone-hexane(4;4;2,V/V/V) and determined by GC/MS,using heptachlor epoxike as internal standard. After the analysis of a tea sample which the pesticides at a level of MRL(maximum residue limit),double the MRL,fivefold the MRL,the average recoveries were 70%-110%, and the limit of determination was 0.01-0.5mg/kg. Good repeatability was obtained in all the cases with coefficients of variation lower than 21%. This method is simple, rapid and sensitive for pesticides residue analysis.