Preparative isolation of the major metabolite NK-1375 of diamide insecticide cyclaniliprole and its application to pertinent residue analysis in plant-origin foods using UHPLC-MS/MS

摘要

NK-1375 is a major metabolite of the diamide insecticide cyclaniliprole (CYCP) with toxicological significance. It is formed in various transformation pathways of CYCP, including photolysis and plant metabolism. In the present study, NK-1375 was produced employing the liquid-phase photolysis of CYCP followed by isolation using preparative liquid chromatography. The structure of the isolated substance was confirmed using MS and 1H NMR spectroscopy, and its purity was measured to be 95.9% using HPLC. As its application, a residue analysis method was first developed for the simultaneous determination of CYCP and NK-1375 in six representative plant-origin foods using fast multi-plug filtration cleanup and UHPLC-MS/MS. Excellent linearity (r > 0.999) was obtained over the calibration range from 0.001 to 0.1 μg mL~-1. The recoveries (intra-day and inter-day) of CYCP and NK-1375 from different matrices ranged from 74 to 112%, with corresponding relative standard deviations less than 13%. The limits of quantitation of these two compounds were defined at 0.01 mg kg~-1. This study can be useful for the subsequent analytical or toxicological research on this important pesticide metabolite.