Abstract

It is found that ionic liquids (ILs) based on imidazole can be used as extractants in the dispersive liquid–liquid microextraction of combined pesticide preparations (imidacloprid, biphenthrin, cypermethrin, malathion, phosalone, and diazinon) followed by their determination by HPLC with electrospray ionization tandem mass spectrometry detection with. The effect of the IL (1-hexyl-3-methylimidazolium tetrafluoborate [C₆MIM] [BF₄], 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C₆MIM] [NTf₂], 1‑butyl-3-methylimidazolium hexafluorophosphate, [C₄MIM] [PF]₆) nature and of the dispersive solvent (acetonitrile, methanol, acetone) volume, extraction time, pH of sample solution, and salting-out agent on the efficiency of analyte extraction is studied. It is found that the maximum recoveries (86–99%) of pesticides were reached using acetonitrile as a dispersive solvent and the [C₄MIM] [PF]₆ ionic liquid as an extractant. The absence of the effect of pH on the distribution of analytes between the water and organic phases confirms the distributive extraction mechanism. The effect of the ionic liquid on the ionization of pesticides is estimated, and conditions of the back extraction of pesticides to hexane are proposed for its reduction.

中文翻译：

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使用离子液体作为萃取剂的农药分散液-液微萃取

摘要

已发现，基于咪唑的离子液体（ILs）可以用作组合农药制剂（吡虫啉，联苯菲林，氯氰菊酯，马拉硫磷，膦酮和二嗪农）的分散液-液微萃取中的萃取剂，然后通过电喷雾色谱法对其进行测定电离串联质谱检测。IL（四氟硼酸1-己基-3-甲基咪唑鎓[C ₆ MIM] [BF ₄ ]，双（三氟甲基磺酰基）酰亚胺1-己基-3-甲基咪唑鎓[C ₆ MIM] [NTf ₂ ]，1-丁基3-甲基咪唑六氟磷酸盐，[C ₄ MIM] [PF] ₆）性质和分散溶剂（乙腈，甲醇，丙酮）的体积，萃取时间，样品溶液的pH值和盐析剂对分析物萃取效率的影响进行了研究。发现使用乙腈作为分散溶剂，并使用[C ₄ MIM] [PF] ₆离子液体作为萃取剂，可达到农药的最大回收率（86-99％）。pH值对水相和有机相之间分析物分布的影响不存在，证实了分布萃取机理。估计了离子液体对农药离子化的影响，并提出了将农药反萃取为己烷的条件，以降低其含量。