To evaluate the uncertainty of liquid chromatography tandem mass spectrometry for the determination of neonicotinoid pesticides in vegetables,the improved QuEChERS high-performance liquid chromatography tandem mass spectrometry method was used to measure the content of three neonicotinoid pesticides(thiamethoxam,imidacloprid,and acetamiprid)in lettuce leaves,and a mathematical model was established to analyze the sources of uncertainty and quantify them.The results showed that when the mass fractions of thiamethoxam,imidacloprid,and acetamiprid in vegetables were 0.047,0.054,0.051 mg/kg,respectively,the standard synthetic uncertainties were 0.003 4,0.004 0,0.005 1 mg/kg,and the extended uncertainties were 0.006 8,0.008 0,0.0100 mg/kg,respectively,at a 95%confidence interval(k=2).The main factors affecting the uncertainty of detection results were standard curve fitting,instrument status,repeatability,and recovery rate.We need to strictly control these aspects.This study provided a reference for the evaluation of the detection results of neonicotinoid pesticise residues in vegetables by liquid chromatography tandem mass spectrometry.
Liquid chromatography tandem mass spectrometryvegetablesneonicotinoid pesticidesuncertainty