QuEChERS-气相色谱-串联质谱法测定茶青中28种农药残留

建立了QuEChERS-气相色谱-串联质谱（GC-MS/MS）同时测定茶青中28种农药残留的分析方法。样品采用乙腈匀浆提取，经75 mg PSA、25 mg C18、4 mg GCB净化，GC-MS/MS多反应离子监测模式下检测，外标法定量。结果表明:在0.020~0.40 mg/L范围内，28种农药的质量浓度与对应的峰面积间呈良好的线性关系，决定系数均大于0.991。在0.10和0.50 mg/kg两个添加水平下，28种农药的平均回收率在77%~106%之间，相对标准偏差（RSD）在1.4%~8.0%（n=6）之间。方法的检出限（LOD）为5.0~20 μg/kg，定量限（LOQ）为10~60 μg/kg。该方法简单、快速、准确、灵敏度高，可用于茶青中多种农药残留的同时检测分析。

Determination of 28 pesticide residues in fresh tea leaves using QuEChERS-gas chromatography-tandem mass spectrometry

A multiresidue analytical method for the determination of 28 pesticide residues in fresh tea leaves was developed and evaluated by using QuEChERS (quick, easy, cheap, effective, rugged and safe) and triple-quadrupole tandem mass spectrometry (GC-MS/MS). Samples were extracted by acetonitrile, and purified by 75 mg PSA, 25 mg C18 and 4 mg GCB, followed by GC-MS/MS detection under multi-reaction monitoring (MRM) mode and quantified by external standard method. Good linearity was achieved between area size and concentration from 0.020 to 0.40 mg/L, with a coefficient of determination higher than 0.991. The average recovery at different spiking levels (0.10, 0.50 μg/kg) was ranged from 77% to 106% with RSD (relative standard deviation, n = 6) 1.4%-8.0%. The LOD (limit of detection) was 5.0-20 μg/kg, and LOQ (the limit of quantification) was 10-60 μg/kg. The method was simple, quick, accurate, highly sensitive and suitable for the simultaneous analysis of multi-residues of pesticides in fresh tea leaves.