固相萃取-GC/LC-MS/MS测定茶叶中79种农药残留

建立了一套以一次固相萃取前处理方法,运用气相色谱-串联质谱（GC-MS/MS）和液相色谱-串联质谱（LC-MS/MS）两种检测技术,测定茶叶中79种农药残留的可靠、快速、高通量检测方法。该方法用20βmL乙腈一次均质提取,分取提取液10βmL,用乙腈+甲苯（3∶1）20βmL洗脱过Carbon/NH₂小柱净化,用5βmL乙腈定容混匀,于GC-MS/MS和LC-MS/MS同时检测。结果表明,79种农药在0.01~0.40βmg·L^-1范围内线性良好,相关系数（R²）在0.995以上;高、低、中3种水平加标回收率在67.3%~130.8%内;相对标准偏差（RSD）在15%内;98.7%的农药定量限（LOQ）≤0.01βmg·kg^-1;使用多种类茶叶实际检测,结果均合格。因此,该方法能同时检测含有机磷、有机氯、拟除虫菊酯类、氨基甲酸酯类和有机杂环类5大类农药,更有利于大批量茶叶样品的多农残检测。

Determination of 79 Pesticide Residues in Tea by Solid Phase Extraction with GC-MS/MS and LC-MS/MS

In order to detect various pesticide residues in tea, a reliable, rapid and high throughput detection method was established: a solid phase extraction was developed for the determination of 79 pesticide residues in tea by gas chromatography-tandem mass spectrometry (GC-MS/MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). These samples were extracted by 20βmL acetonitrile. 10βmL extracts were cleaned by Carbon/NH₂ column with 20βmL acetonitrile + toluene (3∶1) and then mixed with 5βmL acetonitrile, then these procdssed samples were detected by GC-MS/MS and LC-MS/MS, respectively. The results show that the concentrations of 79 pesticide residues had good linearity relationships in the range of 0.01-0.40βmg·L^-1, with the correlation coefficients (R²) above 0.995, the recoveries of high, low and medium levels were ranged from 67.3%-130.8%, the relative standard deviations (RSDs) were less than 15%, the limits of quantification (LOQs) of 98.7 % pesticides were less than or equal to 0.01βmg·kg^-1, multiple types of tea were detected, and the results were proved to be qualified. Consequently, the method can simultaneously detect 5 kinds of pesticides, including organophosphorus, organochlorine, pyrethroids, carbamates and organic heterocyclic pesticides, which would be useful to determine multi-pesticide residues in high numbers of tea samples.