Residue behavior of imidacloprid FS formulation in peanut cultivation system in china and its dietary and ecological risk assessment

Imidacloprid, a key neonicotinoid insecticide for pest control, is widely used in various crops, including peanuts. This study aimed to fill research gaps by analysing the residue behaviour of imidacloprid in peanut fields treated with flowable concentrate for seed treatment (FS) formulations while assessing potential risks to human health and ecosystems. A validated analytical method, using QuEChERS separation and UPLC-MS/MS detection, reliably quantified imidacloprid residues in peanuts and soil. Imidacloprid degradation followed a first-order kinetic model, with half-lives ranging from 21.0 to 46.2 days in plants and 10.3–30.1 days in soil. Residues in peanut kernels were below 0.05 mg/kg, and the maximum soil residue was 0.370 mg/kg. Dietary risk assessment indicated no health risks to adult consumers. However, ecological risk assessment predicted low to moderate earthworm toxicity and a medium risk from ecotoxicity exposure. These findings highlight the importance of adhering to recommended imidacloprid FS seed treatment dosages to minimise adverse effects on non-target soil organisms.