Establishment of a Method for the Detection of Indaziflam, Spirotetramat, Cyantraniliprole, and Their Metabolites and Application for Fruit and Vegetable Risk Assessment

Optimization of a QuEChERS-LC-MS/MS method for 51 pesticide residues followed by determination of the residue levels and dietary intake risk assessment in foodstuffs

A modified QuEChERS purification-liquid chromatography-tandem mass spectrometry method has been developed to determine 51 pesticide residues with newly established maximum residue limits (MRLs) in foodstuffs. Samples were extracted with acetonitrile under citrate-buffered conditions and purified using a modified QuEChERS method employing hydroxylated MWCNTs, SAX, and C18. The limits of quantification ranged from 0.2 to 9.8 µg/kg. Recoveries in ten different foodstuffs ranged from 70.2% to 117.9%, with relative standard deviations between 2.3% and 19.9% at three spiking levels. This method was applied to analyze 352 market samples, detecting 14 pesticides in 97 samples. Notably, Afidopyropen, cyantraniliprole, and fluxapyroxad residues in vegetables exhibited a consistent pattern of higher levels in the spring and winter and lower levels in the summer and autumn. Moreover, the risk assessments for acute and chronic dietary exposure to the 14 detected pesticides indicated that the %ADI and %ARfD were well below 100%.

Dissipation, residues, and evaluation of processing factor for spirotetramat and its formed metabolites during kiwifruit growing, storing, and processing

Spirotetramat is widely used around the world to control sucking pests and may form in agricultural products. In the current study, the dissipation, residues, and evaluation of processing factor (PF) for spirotetramat and its formed metabolites were investigated during kiwifruit growing, storing, and processing. The residue analysis method was established based on high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) combined with a QuEChERS method to detect the residues of spirotetramat and its metabolites in kiwifruit and its processed products. The method provided recoveries of 74.7-108.7%, and the relative standard deviations (RSDs) were 0.6-13.1%. The LOQs of spirotetramat and its four metabolites were 1 μg kg-1. The degradation of spirotetramat was best fitted for the first-order kinetics model with a half-life of 9.90-10.34 days in the field and 24.75-30.13 days during storage. Residues of spirotetramat and its formed metabolites in kiwifruit would not pose dietary risk to consumers. Moreover, the peeling and fermentation were the highest removal efficiency for the spirotetramat and its formed metabolite residues during processing. The PF values calculated after each individual process were < 1, indicating a significant reduction of residues in different processing processes of kiwifruit. The spirotetramat was degraded during kiwifruit wine-making process with half-lives of 3.36-4.91 days. B-enol and B-keto were the main metabolites detected in kiwifruit and its processed products. This study revealed the residues of spirotetramat and its formed metabolites in kiwifruit growing, storing, and processing, which helps provide reasonable data for studying the dietary risk factors of kiwifruits and products.