Simultaneous determination of ten neonicotinoid insecticides and a metabolite in human whole blood by QuEChERS coupled with UPLC-Q Exactive orbitrap high-resolution mass spectrometry

Since neonicotinoid insecticides are now the most extensively used insecticides worldwide, there are increasing cases of neonicotinoid poisoning. A rapid and sensitive method was developed for the determination of ten neonicotinoid insecticides and a metabolite 6-chloronicotinic acid in human whole blood. The types and amounts of extraction solvent, salting-out agent, and adsorbent in the QuEChERS method were optimized by comparing the absolute recoveries of 11 analytes. The separation was performed on an Agilent EC18 column with the gradient elution with 0.1% formic acid in water and acetonitrile as the mobile phase. The quantification was achieved by Q Exactive orbitrap high-resolution mass spectrometry under parallel reaction monitoring scan mode. The 11 analytes showed good linearity with R2 >= 0.9950, LODs ranging from 0.01 mu g/L to 0.30 mu g/L, and LOQs from 0.05 mu g/L to 1.00 mu g/L. The recoveries ranged from 78.3% to 119.9% at low, medium, and high spiked concentrations of blank blood, with matrix effects ranging from 80.9% to 117.8%, inter-day RSDs from 0.7% to 6.7%, and intra-day RSDs from 2.7% to 9.8%. The method was furthermore applied to a real case of neonicotinoid insecticide poisoning to demonstrate its feasibility. The proposed method is suitable for the rapid screening of neonicotinoid insecticides in poisoned human blood in the field of forensic science, as well as monitoring of neonicotinoid insecticide residues in humans in the field of environmental safety, compensating for a lack of studies on neonicotinoid insecticide determination in biological samples.

Automated summary

Since neonicotinoid insecticides are widely used worldwide, a rapid and sensitive method for determining these insecticides in human whole blood was developed. The method optimized the extraction solvent, salting-out agent, and adsorbent in the QuEChERS method. The separation and quantification were achieved using an Agilent EC18 column and Q Exactive orbitrap high-resolution mass spectrometry. The method showed good linearity, low detection and quantitation limits, and satisfactory recoveries and precision. It was successfully applied to a real case of neonicotinoid insecticide poisoning, demonstrating its feasibility for forensic analysis and environmental monitoring.