气相色谱-串联质谱法测定30种果蔬中61种农药的基质效应及其克服方式

Matrix effects and their countermeasures of 61 kinds of pesticides in 30 kinds of fruits and vegetables by gas chromatography-tandem mass spectrometry

中文关键词:  气相色谱-串联质谱法  基质效应  果蔬  农药残留  西葫芦

英文关键词:gas chromatography-tandem mass spectrometry  matrix effects  fruits and vegetables  pesticide residue  zucchini

中文摘要:

      目的 采用气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry, GC-MS/MS)考察30种常见蔬果中61种农药的基质效应, 探索利用替代基质配制标准溶液定量分析的可行性。方法 利用乙腈分别提取30种供试基质, 经分散固相萃取净化后, 利用基质溶液和乙酸乙酯分别绘制基质标准工作曲线和溶剂标准工作曲线, 经GC-MS/MS分析基质效应。结果 所有供试农药在10~200 μg/L线性范围良好, 相关系数(r2)＞0.99。在未净化基质中, 绝大多数农药表现为较强的基质增强效应, 仅有14种农药表现为可忽略的弱基质效应。QuEChERS净化可减小农药在供试基质中的基质效应, 但水胺硫磷、p,p’-滴滴涕、氟虫腈、莠灭净、氟啶脲、异菌脲在各供试基质中仍然表现为强基质增强效应。以西葫芦作为代表基质分析其他供试基质的基质效应, 95%以上数量的农药均表现为中、弱基质效应, 且在25种供试基质中, 80%以上数量的农药表现为可忽略的弱基质效应。采用添加回收的方式对本研究结果进行验证, 当添加水平为0.08 mg/kg时, 利用西葫芦基质配制标准溶液进行定量, 水胺硫磷、氟虫腈、莠灭净的回收率为73.8%~115.8%。结论 在利用GC-MS/MS结合QuEChERS法检测水果蔬菜中的农药残留过程中, 以西葫芦作为代表基质配制基质标准曲线可以有效校正待测农药在其他基质中的基质效应。

英文摘要:

      Objective To investigate the matrix effect of 61 kinds of pesticides in 30 kinds of common vegetables and fruits by gas chromatography-tandem mass spectrometry (GC-MS/MS), and to explore the feasibility of quantitative analysis of standard solution prepared by substitute matrix. Methods Thirty kinds of test substrates were extracted by acetonitrile, and purified by dispersion solid phase extraction. The matrix standard operating curves and solvent standard operating curves were drawn by matrix solution and ethyl acetate, respectively. The matrix effects were analyzed by GC-MS/MS. Results All tested pesticides showed good linearity in the range of 10? 200 μg/L, the coefficients (r2) were more than 0.99. In the unpurified matrix, most pesticides showed strong matrix enhancement effects, and only 14 kinds of pesticides performed weak matrix effects and could be ignored. Generally, matrix effects of most tested pesticides could be reduced by the QuEChERS cleanup procedure, except isocarbophos, p,p-dichlorodiphenyltrichloroethane, fipronil, ametryn, chlorfluazuron and iprodione, which still exhibited strong matrix enhancement effects in all the studied matrices. Using zucchini as a representative matrix to analyze the matrix effects of other test matrices, more than 95% of the pesticides showed medium and weak matrix effects, and among the 25 tested matrices, more than 80% of the pesticides showed negligibly weak matrix effects. The results of this study were verified by the method of additive recovery. When the additive level was 0.08 mg/kg, the standard solution of zucchini matrix was used for quantification. The recovery rates of hydrocarbophos, fipronil, and atrazine were 73.8%?115.8%. Conclusion In the process of using GC-MS/MS combined with QuEChERS method to detect pesticide residues in fruits and vegetables, using zucchini as a representative matrix to prepare a matrix standard curve can effectively correct the matrix effects of pesticides to be tested in other matrices.