超高效液相色谱-串联质谱法同时测定土壤中239种农药的残留量

建立了超高效液相色谱-串联质谱法(UPLC-MS/MS),可于10 min内快速测定土壤中的239种农药残留。土壤样品经AOAC (Association of Official Analytical Chemists) QuEChERS方法处理,用乙腈萃取;无水硫酸镁、乙酸钠固液分离后,过0.2 μm滤膜;在UPLC-MS/MS正、负离子同步扫描多反应监测模式下进行分析。239种农药中,线性相关系数(r²)大于0.99的有236个,占总数的99%。在40 μg/kg添加水平下所有被检测农药的回收率均在50%~150%之间,且相对标准偏差(RSD)均小于20%;其中有209种农药的回收率达到70%~120%,有161种的RSD小于10%。方法的检出限(LOD)范围为0.69~29.04 μg/kg。土壤中多种农药残留的同时检测要求时间短、准确度和精密度高,本方法符合这些检测要求,适用于土壤中农药残留的检测。

Determination of 239 pesticide residues in soil by ultra performance liquid chromatography-tandem mass spectrometry

A method for the determination of 239 pesticides in soil samples by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) is presented. The sample was prepared with AOAC (Association of Official Analytical Chemists) QuEChERS method for the extraction (acetonitrile, anhydrous MgSO₄, CH₃COONa). After filtered with a 0.2 μm membrane, the sample was separated and detected by UPLC-MS/MS performing on positive/negative electrospray ionization (ESI+/-) and the multiple reaction monitoring (MRM) mode. In this study, 236 of the 239 pesticides'' correlation coefficients were above 0.99, which counted 99% of all the analytes. The limits of detection (LODs) ranged in 0.69-29.04 μg/kg (S/N=3). The recoveries of all the pesticides at 40 μg/kg spiked level were in the range of 50%-150%, and the relative standard deviations (RSDs) were below 20%. In addition, the recoveries of 209 pesticides were in the range of 70%-120%, and RSDs of 161 pesticides were less than 10%. The method is efficient, fast, simple, and accurate. The procedure is suitable for the determination of multi pesticide residues in soil.