Determination of imidazole and triazole fungicide residues in honeybees using gas chromatography–mass spectrometry

An analytical method employing clean up by high-performance gel permeation chromatography (HPGPC) and solid-phase extraction (SPE) on Florisil cartridges was developed to determine residues of eleven imidazole and triazole ergosterol-biosynthesis-inhibiting (EBI) fungicides in honeybee samples. Detection was by means of gas chromatography–mass spectrometry (GC–MS) in selected ion monitoring (SIM) mode. The method was validated by fortifying control samples at levels of 0.01 and 0.05 μg/bee. Mean recoveries for each analyte except imazalil were between 79 and 99% with relative standard deviations of 12.3% or less. Mean recoveries of imazalil were 51% at 0.01 μg/bee and 81% at 0.05 μg/bee. Limits of detection for the analytes investigated ranged from 0.005 to 0.001 μg/bee.