不同萃取溶剂提取蔬果中有机氯农药的效果比较

Efficiency comparison of different extraction solvents on extraction of organochlorine pesticides in vegetables and fruits

目的比较不同萃取溶剂对蔬果中21种有机氯农药的提取效果,以探索蔬果中有机氯农药的最佳提取体系。方法选取菠菜、苹果、土豆这3种常见蔬果为代表采集样品,匀浆后分别以乙腈、乙酸乙酯、丙酮、正己烷和1.1(V/V)的乙腈-丙酮、乙腈-乙酸乙酯、乙腈-正己烷、乙酸乙酯-丙酮、丙酮-正己烷和乙酸乙酯-正己烷混合溶剂为萃取剂,经QuEChERS净化后,用气相色谱-质谱法检测样品中的有机氯农药残留。结果上述4种单一溶剂以及6种混合溶剂的平均萃取效率分别为82.5%、80.6%、78.6%、76.5%、92.9%、83.6%、90.3%、82.5%、85.4%、84.1%。结论混合溶剂较单一溶剂萃取效率更高;其中乙腈-丙酮和乙腈-正己烷这2种混合溶剂对蔬果中21种常见有机氯农药的萃取效率最高且稳定性好,可作为常见农药残留的萃取溶剂,以作参考。

Objective To compare the extraction efficiencies of different extraction solvents for 21 organochlorine pesticides in vegetables and fruits,so as to explore the best extraction system for the organochlorine pesticides in vegetables and fruits.Methods The target analytes in homogenized spinach,apple and potato were extracted with acetonitrile,ethyl acetate,acetone,n-hexane,and 1.1(V/V)acetonitrile-acetone,acetonitrile-ethyl acetate,acetonitrile-hexane,ethyl acetate-acetone,acetone-hexane and ethyl acetate-hexane mixed solvents,then cleaned-up by QuEChERS method,and finally separated and detected by gas chromatography-mass spectrometry(GC-MS).Results The average extraction efficiencies of the four single solvents and the six mixed solvents were 82.5%,80.6%,78.6%,76.5%,92.9%,83.6%,90.3%,82.5%,85.4%and 84.1%,respectively.Conclusion Compared to single solvent,the extraction efficiencies of the mixed solvents were higher,and acetonitrile-acetone and acetonitrile-n-hexane have higher and stable extraction efficiency for the organochlorine pesticides in fruits and vegetables.They can be used as extraction solvents for common pesticide residues.