Comprehensive multiresidue chromatographic methods for monitoring pesticides in agricultural areas and corresponding plant protection zones

Abstract

This article reports a comprehensive analytical method for the identification and quantification of a broad range of pesticides in green plant crops. The sample preparation method for pesticides involved an optimization of the QuEChERS-based extraction protocol, with sample mass, volume of added water, and the type of cleanup sorbent as variables. A sorbent combination based on ENVI-Carb and ChloroFiltr was examined. A highly efficient method was developed for the purification of plant extracts with 900 mg MgSO4, 150 mg PSA, and 15 mg ENVI-Carb at the d-SPE stage, combined with gas chromatography and liquid tandem mass spectrometry for the determination of 197 pesticides in crop plants containing chlorophyll. The method was validated in accordance with the requirements of international guidelines SANTE/11312/2021. The method was applied to quantify pesticide residues in 29 pairs of green crop plants and plants from the corresponding crop protection zone to verify whether the zones are effective barriers to prevent pesticides from penetrating outside agricultural areas. The number and types of agrochemical preparations were chosen by farmers. In total, more than 60 one- and several-component pesticide formulations were applied to the crops included in the study. The pesticide residues were detected in 21 crop samples and 3 samples from protection zones. Epoxiconazole, an active substance that was banned for use in 2021, was found in a spring barley sample. Based on the conducted research, the effectiveness of the protection zones has been clearly demonstrated, and it has been proven that environmental migration of pesticides and unauthorized agricultural practices pose a risk to ecosystems.