气相色谱-串联质谱法测定茶叶中32种杀菌剂残留

建立了茶叶中32种杀菌剂类农药残留的气相色谱-串联质谱(GC-MS/MS)测定方法。样品经乙腈高速匀浆提取后,以N-丙基乙二胺(PSA)、石墨化碳(GCB)、C18为净化剂进行净化,在GC-MS/MS多反应离子监测(MRM)模式下进行测定,空白基质匹配标准曲线外标法定量。结果表明:27种杀菌剂在10~1 000μg·L~(-1),5种杀菌剂在20~1 000μg·L~(-1)范围内具有良好线性关系,相关系数(R~2)均大于0.99。方法检出限(S/N≥3)为0.1~8.1μg·L~(-1),定量限(S/N≥10)为0.4~23.4μg·L~(-1),平均添加回收率范围为70.4%~109.1%,相对标准偏差(RSD)3.4%~10.3%。该方法样品前处理操作简单、净化效果好、灵敏度高,具有良好的适用性,能够满足茶叶中多种杀菌剂残留测定分析的要求。

Determination of 32 Fungicide Residues in Tea by Gas Chromatography-Tandem Mass Spectrometry

A gas chromatography-tandem mass spectrometry (GC-MS/MS) method was developed for detecting 32 fungicide residues in teas.The samples were extracted by acetonitrile under high-speed homogenization, purified with PSA, GCB, C18, and determined by GC-MS/MS in multi-reaction ion monitoring mode.Pesticide contents were determined by using the standard curves constructed with solutions of respective external standards.Linearity of the curves for 27 pesticides ranged from 10 μg·L-1 to 1 000 μg·L-1, and from 20 μg·L-1 to 1 000 μg·L-1 for the remaining 5 pesticides, with correlation coefficients greater than 0.99.The limits of detection were 0.1-8.1 μg·L-1 (S/N≥3);and, those of quantification,0.4-23.4 μg·L-1 (S/N≥10).The average recovery rates were 70.4%-109.1%;and RSD (n =6) 3.4%-10.3%.The newly developed highly sensitive methodology that required simple pre-treatment and effective purification procedures appeared to be appropriate for the detection of fungicide residues in teas.