土壤中痕量氨基甲酸酯和三唑类农药的样品提取方法研究

本文对比研究了QuEChERS、加速溶剂萃取和超声提取三种方法,结合液相色谱-串联质谱法解决了土壤中18种极性强、热稳定性差的痕量氨基甲酸酯和三唑类农药提取难题。研究表明,Qu ECh ERS法的基体加标回收率为76.3%~121.0%(除涕灭威为27.5%外),超声提取法为71.0%~100.0%(除涕灭威为4.7%,涕灭威亚砜为137.8%外),加速溶剂萃取法大多低于70%(甲硫威、涕灭威、三唑醇几乎没有回收),可见QuEChERS法比另两种提取方法结果更优,最终确定为检测氨基甲酸酯类和三唑类农药的样品提取方法。涕灭威回收率偏低、涕灭威亚砜回收率偏高与提取方法的热效应有关;仲丁威、甲萘威等组分的回收状况与土壤类型相关。

Sample Extraction Methods for Determining Trace Carbamate and Triazole Pesticides in Soil

QuEChERS method, Accelerated Solvent Extraction(ASE) and Ultrasound Extraction(UE) were used for sample extraction and are reported in this paper. Combined with liquid chromatograph coupled with mass spectrometry, these extraction methods were used to determine eighteen kinds of trace carbamate and triazole pesticides in soil with strong polarity and poor thermal stability. Results show that the standard addition recoveries of the QuEChERS method range from 76.3% to 121.0% with the exception of aldicarb(27.5%), whereas those of UE ranged from 71.0% to 100.0% with the exception of aldicarb(4.7%) and aldicarb sulfoxide(137.8%). The recoveries of ASE are mostly below 70%, but methiocarb, aldicarb and triadimenol are almost not recovered. Therefore, the QuEChERS method was eventually chosen as the sample extraction method for determining carbamate and triazole pesticides. The low recovery of aldicarb and high recovery of aldicarb sulfoxide were related to the heating effect of the extraction method, whereas the recoveries of fenobucarb and carbaryl were related to soil types.