Validation of a QuEChERS-Based Method for the Estimation of Afidopyropen in Brinjal (Solanum Melongena L.) and Soil

: Background: Afidopyropen is a recently introduced insecticide that provides effective control of insect pests in vegetable crops, including brinjal. Field applications of this insecticide can often result in accumulation of residues in brinjal fruits, leaves, and soil at harvest, which might be a concern for food and environmental safety. This demands an appropriate method for analysis of the residues of this insecticide in these matrices to facilitate residue monitoring and safety compliance checks. Objective: The study aims to validate a quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based method for estimation of afidopyropen in/on brinjal leaf, fruit, and soil by ultrahigh-performance liquid chromatograph-tandem mass spectrometer (LC-MS/MS). Methods: The brinjal fruit, leaf, and soil samples were extracted by an optimized QuEChERS workflow-based sample preparation method and analyzed by LC-MS/MS. Results: Linearity [with coefficient of determination (R²) >0.99] was obtained in calibration curves drawn from standards prepared in the matrix and neat solvent. Although negligible matrix effects were noted in fruit and soil, ion suppression was significant in the leaf matrix (71.6%). The recoveries were within the acceptable range of 70-120%, with relative SD ≤20%. In all cases, Horwitz ratio values were within the acceptable range of 0.3-1.3, indicating satisfactory repeatability. The LOQs were 0.004, 0.001, and 0.001 mg/kg for brinjal fruit, leaf, and soil, respectively. At the spiking concentrations of 0.01, 0.05, and 0.1 mg/kg, the estimated measurement uncertainty was <50% for all matrices. Conclusions: Because of its satisfactory precision and accuracy, the proposed method can be extended for estimation of afidopyropen in other vegetables for evaluating maximum residue limit compliance. Highlights: The study reports an optimized method for high-throughput residue analysis of afidopyropen in/on brinjal leaf, fruit, and soil. The accuracy, precision, selectivity, and sensitivity of the method comply with the regulatory requirements.