Isotope-labeled internal standards and grouping scheme for determination of neonicotinoid insecticides and their metabolites in fruits, vegetables and cereals – A compensation of matrix effects

Neonicotinoid insecticides (NIs) are widely used. However they produce high levels of residues and are toxic to non-target organisms, especially when their metabolites exhibit comparable or elevated toxicities. In this study, we established a multi-residue analytical method for analyzing 20 compounds - 8 NIs and their 11 major toxic metabolites. QuEChERS pretreatment and ultra-high-performance liquid chromatography-tandem mass spectrometry were...