气相色谱-串联质谱法测定普洱晒青毛茶中192种农药残留量

Determination of 192 kinds of pesticide residues in Pu’er tea by gas chromatography tandem mass spectrometry

中文关键词:  普洱茶  农药多残留  气相色谱-串联质谱法  多反应离子检测

英文关键词:Pu’er tea  multi-pesticide residue  gas chromatography tandem mass spectrometry  multi-reaction monitoring

中文摘要:

      目的 建立气相色谱-串联质谱法(gas chromatography tandem mass spectrometer, GC-MS/MS)测定普洱茶中192种农药(包括同分异构体)残留的分析方法。方法 普洱晒青毛茶样品用乙腈过夜浸泡后振摇提取, 浓缩后经Clearnet TPT固相萃取柱净化, 样品采用气相色谱-串联质谱法选择MRM模式测定, 以环氧七氯为内标物定量。通过检出限、定量限、加标回收率、线性范围验证方法的可行性。结果 所有农药在0.025~1.6 mg/L范围内, 线性关系r2在0.995以上; 方法的检出限和定量限范围分别为0.0003~0.25 mg/kg、0.0009~0.8 mg/kg; 加标水平分别为0.025、0.05、0.1 mg/kg时, 农药的平均回收率范围为64%~126%, 相对标准偏差均小于9.8%。结论 该方法灵敏度、准确度和精密度良好, 符合多农药残留检测的技术要求。

英文摘要:

      Objective To establish a method for the determination of 192 kinds of pesticides residues in Pu’er tea by gas chromatography tandem mass spectrometry (GC-MS/MS). Methods The sample of Pu’er sun tea was soaked in acetonitrile overnight, shaken and extracted, concentrated and purified by Clearnet TPT solid phase extraction column. The samples were determined by gas chromatography-tandem mass spectrometry with multi-reaction monitoring (MRM) mode and quantified by epoxy heptachlor. The method was validated according to the limit of detention (LOD), limit of quantitative (LOQ), and the percentage of recovery and linearity range. Results The correlation coefficients (r2) of all pesticides residues were more than 0.995 with the concentration range of 0.025-1.6 mg/L. The LODs and LOQs of the method were 0.0003-0.25 mg/kg and 0.0009-0.8 mg/kg, respectively. The average recoveries of pesticides ranged from 64% to 126%, and the relative standard deviations were less than 9.8% at spiked levels of 0.025, 0.05 and 0.1 mg/kg. Conclusion This method is sensitive, accurate and precise, which can meet the technical requirements for multi-pesticide residue detection.