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 mu g 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%. (C) 2011 Elsevier B.V. All rights reserved.