Enantioselectivity and residue analysis of cycloxaprid and its metabolite in the pile and fermentation processing of Puer tea by ultraperformance liquid chromatography–high‐resolution mass spectrometry

Abstract

Neonicotinoids are the most important class of synthetic insecticides for tea protection against piercing-sucking pests (Tomizawa & Casida, 2003). Cycloxaprid is a new neonicotinoid insecticide that has been synthesized and industrialized in China (Li et al., 2011). It is different from traditional neonicotinoids, which act as agonists of native and recombinant nicotinic acetylcholine receptors (nAChRs )

Metabolite of chiral cycloxaprid in solvent and in the raw of Puer tea

“…Metabolite × was the major metabolite reported by our previous results ( Liu et al, 2022 ). The metabolite and standard were simultaneously analyzed by LC-HFMS, and their retention time, molecular ion peak, and fragmentation pattern were in agreement with the synthesized structure standard of 2 -chloro-5 -[[-2 -(nitromethylidenc) imidazodin-1 -yl] methyl] pyridine (CAS 10336–63-4).…”

“…Because its special processing, the Puer tea is fermented by traditional technology in long-distance transport with consign for horse. Previous our studied that one mainly metabolite was reported in Puer tea processing ( Liu et al, 2022 ) but, the relevant information of degradation pathway and metabolite of CYC was still incomplete ( Fig. 1 ).…”

“…Previous studies shown that the stereomiosmer had been found in soil or food. Liu et al 2022 found the enantioselectivity of cycloxaprid in raw or ripen Puer tea processing. Zhang et al 2013 observed stereoselective uptake and translocation of cycloxaprid in edible vegetables from roots.…”

Enantioselective Behaviors of Chiral Pesticides and Enantiomeric Signatures in Foods and the Environment

“…Enantioselective residues of indoxacarb in commercial green tea and black tea products were found, with the EF values ranging from 0.274 to 0.475 . During Puer tea processing, 1 R ,2 S -cycloxaprid dissipated faster than 1 S ,2 R -cycloxaprid in raw tea or ripen tea processing, indicating the preferential degradation of 1 R ,2 S -cycloxaprid . Pickle is a type of fermented food with a long history, which is made by preserving raw vegetables in brine solution under the action of microorganisms for a certain period of time.…”

“…114 During Puer tea processing, 1R,2S-cycloxaprid dissipated faster than 1S,2Rcycloxaprid in raw tea or ripen tea processing, indicating the preferential degradation of 1R,2S-cycloxaprid. 142 Pickle is a type of fermented food with a long history, which is made by preserving raw vegetables in brine solution under the action of microorganisms for a certain period of time. Enantioselective degradation of diclofop-methyl was found during the cabbage pickling process.…”