Validation of QuEChERS Method Coupled with LC-MS/MS for Determination of Thiamethoxam and its Metabolites in Wheat and Soil

Abstract

Abstract Background Thiamethoxam, a neonicotinoid insecticide, has been widely accepted for the control of sucking and certain chewing pests. Through different routes, i.e., wind drift, leaching, and surface runoff, it can reach non-target areas, which include humans as well. Therefore the fate of thiamethoxam in food grains and soil is of prime importance, entailing a need for pesticide use to be subject to steady observation. Objective The review aimed to validate the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method for the detection of thiamethoxam and its metabolites in wheat leaves, grain, straw, and soil using liquid chromatography–tandem mass spectrometry (LC-MS/MS). Method The QuEChERS method allows sample extraction by acetonitrile followed by cleanup with a primary secondary amine sorbent, magnesium sulphate, and graphitized carbon black. The method was validated in terms of selectivity, linearity, LOD, LOQ, matrix match, accuracy, and precision. The estimation of residues was done by LC-MS/MS. Results The recovery of thiamethoxam and its metabolites in wheat and soil samples was in the range of 81.22–98.14%. The LOQ for thiamethoxam and its metabolites was 0.01 mg/kg. The matrix effect values were in the acceptable range of –20 to +20%. Conclusions The method allows a simple and fast extraction of thiamethoxam and its metabolites from wheat leaves, grain, straw, and soil. It could be helpful in the evaluation of regulatory and food safety decisions regarding the use of neonicotinoids. Highlights The method was validated according to the European Commission SANTE/12682/2019 guidelines. An accurate, simple, and sensitive analytical method was validated for thiamethoxam and its metabolites.