Combination of high specific activity carbon-14 labeling and high resolution mass spectrometry to study pesticide metabolism in crops: Metabolism of cycloxaprid in rice. (December 2021)

• Record Type: Journal Article
• Authors: Shen, Dahang; Lu, Zhijiang; Zhong, Jiayin; Zhang, Sufen; Ye, Qingfu; Wang, Wei; Gan, Jay
• Is Part Of: Environment international. Volume 157(2021)
• Publication Date: 2021-12
• Subjects: Metabolites -- Pesticide metabolism -- Cycloxaprid -- High-specific activity 14C labeling -- HRMS; Environmental protection -- Periodicals; Environmental health -- Periodicals; Environmental monitoring -- Periodicals; Environmental Monitoring -- Periodicals; Environnement -- Protection -- Périodiques; Hygiène du milieu -- Périodiques; Environnement -- Surveillance -- Périodiques; Environmental health; Environmental monitoring; Environmental protection; Periodicals; 333.705
• DOI: 10.1016/j.envint.2021.106879
• Languages: English
• ISSNs: 0160-4120

Abstract

Graphical abstract: Abstract: The study of pesticide metabolism in crops is critical for assessing the mode of action and environmental risks of pesticides. However, the study of pesticide metabolism in crops is usually complicated and it is often a daunting challenge to accurately screen the metabolites of novel pesticides in complex matrices. This study demonstrated a combined use of high-specific activity carbon-14 labeling and high-resolution mass spectrometry (HSA- 14 C-HRMS) for metabolism profiling of a novel neonicotinoid cycloxaprid in rice. By generating the characteristic radioactive peaks on the liquid chromatogram, the use of 14 C can eliminate the severe interference of complex matrices and quickly probe target compounds; by producing ion pairs with unique abundance ratios on HRMS, high-specific activity labeling can effectively exclude false matrix positives and promote the elucidation of metabolite structure. The structures of 15 metabolites were identified, three of which were further confirmed by authentic standards. Based on these metabolites, a metabolic profile of cycloxaprid was established, which includes denitrification, demethylation, imidazolidine hydroxylation and ring cleavage olefin formation, oxidation and carboxylation reactions. The strategy of combining high-specific activity 14 C labeling and HRMS offers unique advantages and provides a powerful solution for profiling unknown metabolites of novel pesticides in complex matrices, especially when traditional non-labeling methods are not feasible.