Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), Universidad de Las Palmas de Gran Canaria, Paseo Blas Cabrera s/n, 35016 Las Palmas de Gran Canaria, Spain.
Department of Environmental Analysis, Technological Institute of the Canary Islands, C/Los Cactus no 68 35118, Polígono Industrial de Arinaga, Agüimes, Las Palmas, Canary Islands, Spain.
Sci Total Environ. 2021 Jan 20;753:142015. doi: 10.1016/j.scitotenv.2020.142015. Epub 2020 Aug 26.
A modified QuEChERS method was optimized, validated and verified for the extraction of 218 pesticide residues in agricultural soil samples. The 218 analytes are extracted using a single step, without clean-up, with matrix-matched calibration, and two complementary techniques: liquid and gas chromatography tandem triple quad mass spectrometry (LC-MS/MS and GC-MS/MS). Some of the parameters such as salts, acidity of the extraction solvent, sample moisture and some mechanical changes in the procedure were optimized to improve the overall performance for the target compounds and the soil matrix. The method was fully validated on a representative agricultural soil sample of the Canary Islands (clay loam soil) in terms of linearity, accuracy and precision. To avoid matrix effects, matrix-matched calibration curves (R ≥ 0.99) were used for all target analytes. 100% of the compounds can be quantified with limits of quantification (LOQ) lower than the limit typically used in soils (50 ng g), with 92% of compounds presenting a LOQ that is at least 10 times lower than that normally required. The limits of detection (LOD) ranged between 0.024 and 6.25 ng g. The validated method was applied to a series of actual samples of agricultural soil (n = 18). In addition, as a further verification of its potential, the results of the application of the method in the investigation of clay loam soil samples that were obtained from underneath wildlife carcasses in the context of an environmental forensic investigation are also presented.
优化、验证和确认了一种改良的 QuEChERS 方法，用于提取农业土壤样品中的 218 种农药残留。使用单步提取法，无需净化，采用基质匹配校准和两种互补技术：液相色谱-串联三重四极杆质谱法（LC-MS/MS）和气相色谱-串联三重四极杆质谱法（GC-MS/MS）。优化了一些参数，如盐、提取溶剂的酸度、样品水分和程序中的一些机械变化，以提高目标化合物和土壤基质的整体性能。该方法在加那利群岛（粘壤土）的代表性农业土壤样品上进行了全面验证，包括线性、准确性和精密度。为避免基质效应，所有目标分析物均采用基质匹配校准曲线（R≥0.99）。100%的化合物可以定量，定量限（LOQ）低于通常用于土壤的限量（50ng g），92%的化合物的 LOQ 至少低 10 倍。检测限（LOD）范围在 0.024 到 6.25ng g 之间。验证后的方法应用于一系列实际的农业土壤样品（n=18）。此外，作为对其潜在应用的进一步验证，还介绍了该方法在环境法医调查背景下从野生动物尸体下获得的粘壤土样本中应用的结果。
