Residue and metabolism of imidacloprid in cherry radish using a 14C study: Implications for food safety

Although imidacloprid is widely used and registered for radish cultivation in China, its metabolic fate in radish remains unclear, posing uncertainties in consumer safety. Herein, we employed 14 C-imidacloprid to elucidate its distribution and metabolism in cherry radish. Residue analysis showed higher accumulation in shoots (1.15–1.32 μmol) than roots (0.0210–0.0678 μmol). Imidacloprid in radish dissipated following first-order kinetics, with a half-life of 18.5 d. Parental imidacloprid was confirmed in roots, while four metabolites, predominantly olefin and 4/5-hydroxy imidacloprid, were identified in shoots. The proposed pathway involves hydrolysis of the imidazole ring to form hydroxyl derivatives, followed by dehydration to olefin products. Notably, dietary risk assessment revealed risk quotient values up to 20 % in some individuals consuming radish leaves, highlighting the need for stricter monitoring. Overall, these findings fill the knowledge gap regarding imidacloprid metabolism in radishes and offer vital insights into optimizing pesticide usage while maintaining food safety.