Residue and chronic dietary exposure risk assessment of sulfoxaflor and spinetoram in Asparagus officinalis

To clarify the dietary risk of residues of sulfoxaflor and spinetoram in Asparagus officinalis, supervised residue trials of sulfoxaflor 240 g/L suspension concentration (SC) and spinetoram 60 g/L SC were carried out at six locations over a period of one year. Based on the ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS), the dissipation, residue levels and dietary risk of sulfoxaflor, spinetoram and its metabolites in A. officinalis were determined and evaluated. The results showed that the average recoveries of sulfoxaflor, spinetoram and its metabolites in A. officinalis were 86%-105% at three spiked levels (0.005-1.0 mg/kg), and the relative standard deviations (RSD) were lower than 11%. The limits of quantification (LOQ) were 0.005 mg/kg. Following the first-order kinetics, the half-lives of sulfoxaflor and spinetoram were in range of 1.1-1.9 d and 1.3-2.1 d, respectively, showing a rapid dissipation trends. At a sampling interval of 3 days after the last application, the residue levels of sulfoxaflor in A. officinalis samples were<0.005-0.194 mg/kg, and the residues of spinetoram were<0.01-0.041 mg/kg. The chronic dietary intake risk assessment at average and 97.5% food consumption showed that the contribution rate of A. officinalis and spinetoram residues to the ADI for general population were less than 0.2%.These results suggested that the risk of chronic dietary intake of sulfoxaflor and spinetoram residues through A. officinalis were very low. The study provided basic data for the scientific and reasonable use of sulfoxaflor and spinetoram on A. officinalis, and also for the establishment of their maximum residue limits (MRLs).