Simultaneous Determination of Multiresidues of Pesticides and Veterinary Drugs in Agricultural Soil Using QuEChERS and UHPLC–MS/MS

Abstract

Soil is one of the main destinations for pesticides and veterinary drugs used in agriculture and animal production. The negative consequences of the accumulation of these compounds in the environment make it important to monitor these compounds in the soil. In this study, we compared different extraction procedures using solvent shaking, ultrasound, or QuEChERS, and their combinations, for the simultaneous determination of 75 pesticide and seven veterinary drug residues in agricultural soil by ultra-high performance liquid chromatography coupled to serial mass spectrometry (UHPLC–MS/MS). The method using QuEChERS combined with shaking showed the best results for soil using the addition of water, followed by extraction with acetonitrile acidified with acetic acid and shaking in a shaker. For partitioning, anhydrous magnesium sulfate and anhydrous sodium acetate were used. The extract was centrifuged, filtered, and diluted (1:4, v/v) in water for determination by UHPLC–MS/MS. Method validation showed adequate accuracy and precision results, with recoveries between 70 and 120% and RSD ≤ 20% for the vast majority of the compounds evaluated at the spike levels of 10, 25, 50, and 100 μg kg−1. The method limits of detection (LOD) and quantification (LOQ) ranged from 3.0 to 7.5 μg kg−1 and from 10 to 25 μg kg−1, respectively. The method was applied to different agricultural soil samples and proved to be efficient for routine analysis.

Keywords

• soil
• pesticides
• veterinary drugs
• sample preparation
• LC–MS/MS