Determination of imidacloprid and its relevant metabolites in tomato using modified QuEChERS combined with ultrahigh‐pressure liquid chromatography/Orbitrap tandem mass spectrometry

Abstract

BACKGROUND Red tomato processing is one of the leading industries in Xinjiang, but also the largest export industry. In the process of tomato planting, imidacloprid (IMI) is often used to kill aphids, which poses the risk of pesticide residue. However, as daily consumables, pesticide residue on tomatoes may cause a potential threat to human health. Therefore the aims of this research were to study the residue dynamics of IMI pesticides in tomatoes by monitoring field experiments and to investigate the fate of IMI and its metabolites under Xinjiang field conditions. RESULTS In the field trials, three different doses of IMI were sprayed on tomato during the fruit setting stage. Degradation of IMI and residue behaviors of its metabolites at different stages were systemically traced and evaluated by ultrahigh‐performance liquid chromatography coupled with tandem mass spectrometry (UHPLC/Q‐Orbitrap MS). An accurate mass tool was used as the main method to identify the IMI metabolites. The improved method showed high efficiency in detecting IMI and 6‐chlorinated nicotinic acid (6‐CNA), being able to determine hazardous pesticides at trace levels. The fate of IMI in field tomato was investigated over 28 days. The metabolic mechanism of IMI in tomato is: OH products in the early stage and carbonyl products in the late stage. CONCLUSION Under natural conditions, pesticides in tomatoes will gradually decrease with time. In this process, olefin IMI is produced, but it is almost completely metabolized after 28 days. Therefore even 10 times the recommended dose of IMI pesticide will not endanger human health. © 2019 Society of Chemical Industry

Residue levels of emamectin benzoate, imidacloprid and its major metabolites in cabbage from 12 regions in China and dietary risk assessment

“…There was no hydroxylation of IMI in sugarcane (Smriti & Balwinder, 2014), so the metabolites 5‐OH and IMI‐olefin were not detected, but IMI‐olefin was the main constituent of IMI residues in rice (Akoijam & Singh, 2014). In addition, Li et al studied the metabolic mechanism of IMI in tomato (Li, Jiang, & Li, 2019) and found that OH products were detected in the early stage and carbonyl products in the late stage. The above research confirmed that IMI could be converted into different metabolite structures in different crops, and Chen et al found that 5‐OH, IMI‐olefin, IMI‐urea and 6‐CNA were undetected in cabbage (Chen et al, 2021), which also indicated that the results of this study are credible.…”

“…There was no hydroxylation of IMI in sugarcane (Smriti & Balwinder, 2014), so the metabolites 5-OH and IMI-olefin were not detected, but IMI-olefin was the main constituent of IMI residues in rice (Akoijam & Singh, 2014). In addition, Li et al studied the metabolic mechanism of IMI in tomato (Li, Jiang, & Li, 2019) and found that OH products were detected in the early stage and carbonyl products in the late stage.…”

Dissipative behavior, residual pattern, and risk assessment of four pesticides and their metabolites during tea cultivation, processing and infusion

“…1, three primary metabolites of imidacloprid in tea were detected in this study. Imidacloprid desnitro was generated by denitrification, and then it was further oxidized to carbonyl imidacloprid (imidacloprid‐urea) 39 . Meanwhile, 6‐chloronicotinic acid was also detected with low residual concentration.…”

“…Imidacloprid desnitro was generated by denitrification, and then it was further oxidized to carbonyl imidacloprid (imidacloprid-urea). 39 Meanwhile, 6-chloronicotinic acid was also detected with low residual concentration. The residue concentrations of them reached to 1.73, 0.55, and 0.06 mg/kg at the third day after application in Sichuan, respectively.…”

Residue, Dissipation Pattern, and Dietary Risk Assessment of Imidacloprid in Chinese Chives

“…Other experimental field studies have shown that the dissipation dynamics of imidacloprid are affected by various factors, including crop type, climate and environmental conditions, application dose and timing, and co-application with other pesticides ( 27 , 28 ). In this context, Li et al ( 29 ) investigated the final residues and the dissipation dynamics of imidacloprid in tomatoes by LC-MS/MS, with a half-life of 14.43 days and R 2 = 0.90. Imidacloprid in tomatoes decreased rapidly during the first 7 days.…”