同位素稀释气相色谱-质谱法测定茶叶中5种杀菌剂残留

建立了使用固相萃取-气相色谱/质谱联用结合同位素稀释技术准确测定3种茶叶(红茶、绿茶和普洱茶)中敌菌丹、克菌丹、灭菌丹、百菌清和苯氟磺胺等杀菌剂农药残留的新方法。茶叶试样中加入同位素内标D6-克菌丹,经乙腈匀浆提取,提取液离心后取上清液经Forisil固相萃取柱浓缩、净化。GC-MS采用选择离子监测(SIM)模式进行定性定量分析,内标法定量。方法的添加回收率为74.1%～100.6%;相对标准偏差为1.2%～12%;6种农药的检出限为0.002～0.14μg/mL。

Determination of five fungicide residues in tea by gas chromatography-mass spectrometry with isotopic dilution method

A new method using isotopic dilution and solid phase extraction (SPE) technique was established to determine the residues of captafol, captan, folpet, chlorothalonil, and dichlofluanid in three kinds of tea (red tea, green tea and Pu'er) by gas chromatography-mass spectrometry (GC-MS). Isotope internal standard, D6-captan was added into tea leaves, and the sample was extracted by acetonitrile and cleaned up by solid phase extraction using Florisil sorbent. The mass spectrometer was operated with selected ion monitoring (SIM) mode. The target analytes were quantified by isotope internal standard method. Average recoveries ranged from 74.1% to 100.6% and relative standard deviations were 1.2%～11% at six fortified levels. Detection limits of five fungicides were 0.002～0.14 μg/mL.The proposed method is characterized by simplicity, high sensitivity and accuracy.