Comprehensive target analysis for 19 pyrethroids in tea and orange samples based on LC-ESI-QqQ-MS/MS and LC-ESI-Q-ToF/MS

Abstract

A practical, efficient, and rapid method for quantifying 19 pyrethroids in tea and orange samples was developed in this research. After extracting pyrethroids through QuEChERS procedure, liquid chromatography electrospray ionization quadrupole-time-of-flight mass spectrometry (LC-ESI-Q-ToF/MS) was applied to elucidate the fragmentation pathways and product ions of 19 pyrethroids. The identified ions were exclusive targets to quantify 19 pyrethroids by triple quadrupole mass spectrometry (LC-ESI-QqQ-MS/MS). Confirmation and quantification transition ions of 19 pyrethroids were fragmented from either ammonium adducts or hydrogenated molecules. Analytical performances, including method limits of detection (0.07–0.29 μg/kg), linearities (0.9914–0.9993), relative standard deviations (1.6–5.0%), and recoveries (89.8–109.5%), met the requirements of Chinese National Standards. Matrix-matched standard curves were employed for the calibration of some pyrethroids with medium matrix effect in tea and orange samples. The detection and quantification of 19 pyrethroids from local tea and orange samples revealed that no pyrethroid was tested out from 209 peeled orange samples. Although 11 pyrethroids were detected positive from 161 out of 262 tea samples with the means of concentration ranging from 15 to 169 μg/kg, their levels were still below maximum residue limits.