Multiresidue Analysis Method for the Determination of 477 Pesticides in Soil Based on Thorough Method Validation

Pesticide residues have long been a critical concern in soil pollution investigation and assessment. High-throughput and simplified analytical methods are essential for pesticide residue screening. However, previous methods have been limited in their comparison with classical approaches, and their reliability has not undergone systematic validation. In this study, a simplified and robust multiresidue analytical method for 477 pesticides in soil samples was developed using a modified QuEChERS approach combined with liquid and gas chromatography-triple quadrupole mass spectrometry (LC-MS/MS and GC-MS/MS). Key factors influencing method performance, including sample hydration and buffer systems, were systematically optimized. Furthermore, the method was rigorously validated across diverse soil matrices, aged soils, and incurred soil samples, with concurrent comparison to the classical accelerated solvent extraction (ASE) technique. Recoveries for most pesticides ranged from 70% to 120%, with relative standard deviations (RSDs) < 20%, indicating satisfactory accuracy. The limits of quantification (LOQ) ranged from 2 to 20 μg/kg for target pesticides. Calibration linearity yielded correlation coefficients (r²) > 0.990 for all pesticides. The proposed method was successfully applied to analyze actual soil samples, with results indicating that all samples were contaminated with pesticides.