Investigation of the degradation kinetics of pirimicarb in different pepper (Capsicum annuum L.) varieties

This study investigated the dissipation kinetics of pirimicarb in five different varieties of pepper (Capsicum annuum L.) under open-field conditions in the central district of Tokat during the 2023 growing season. Pirimicarb, a carbamate insecticide, was applied to control the green peach aphid (Myzus persicae (Sulzer)). Following application, plant samples were collected at predetermined intervals. The samples were prepared for analysis using the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method, and pirimicarb residues were quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The analytical method was validated in accordance with SANTE/11312/2021 guidelines, with determined limits of detection (LOD) and quantification (LOQ), recovery, and relative standard deviation (RSD) values all falling within acceptable ranges. Residue analysis demonstrated that pirimicarb residues in all five pepper varieties declined below the European Union maximum residue limit (EU MRL, 0.5 mg/kg) within 24 hours post-application. The half-life of pirimicarb varied significantly among the varieties, calculated as follows: 1.99 days in Three-lobed pepper, 2.19 days in Bell pepper, 2.30 days in Long green pepper, 2.51 days in Charleston pepper, and 3.07 days in Capia pepper. The observed significant differences in dissipation rates and half-lives are likely attributable to variations in the morphological and physiological characteristics of the pepper varieties. These findings indicate that the dissipation kinetics of pirimicarb are variety-specific. This underscores the critical importance of considering varietal differences when evaluating pesticide residue behavior to ensure consumer safety and to develop science-based, sustainable pest management strategies. Consequently, this study addresses a significant knowledge gap in the field of agricultural toxicology.