Determination of organophosphorus pesticides in peanut oil by dispersive solid phase extraction gas chromatography–mass spectrometry

The organophosphorus pesticides including phorate, diazinon, tolclofos-methyl, fenitrothin, malathion, fenthion, isocarbophos, quinalphos and phenamiphos, in peanut oils were determined by liquid–liquid extraction coupled with dispersive solid phase extraction and gas chromatography–mass spectrometry (GC–MS). The mixture of multi-walled carbon nanotubes and alumina was used as adsorbent in dispersive solid phase extraction. The effects of some experimental conditions, such as types of multi-walled carbon nanotubes, amount of adsorbents and extraction time were examined. The limits of detection for the analytes were between 0.7 and 1.6 μg kg−1. The obtained recoveries of the analytes in the samples were between 85.9 and 114.3% and relative standard deviations were lower than 8.48%.

► A modified QuEChERS method was used to extract pesticide residues from peanut oil. ► Multi-walled carbon nanotubes and alumina were used as adsorbent for clean-up step. ► The method has stronger purifying ability and higher sensitivity.