Simultaneous multidetermination of residues of pesticides and polycyclic aromatic hydrocarbons in olive and olive-pomace oils by gas chromatography/tandem mass spectrometry

A multiresidue method for determining major pesticides and polycyclic aromatic hydrocarbons (PAHs) in olive oils in a single injection by use of gas chromatography/tandem mass spectrometry (GC-MS/MS) is proposed. Samples are previously extracted with an acetonitrile/n-hexane mixture and cleaned up by gel permeation chromatography. Electron ionization and chemical ionization allow pesticides and PAHs to be determined in a single analysis. The precision obtained was quite satisfactory (relative standard deviations ranged from 3 to 7.8%), and so were recoveries (84-110%). The linear relation was observed from 1 to 500 mu g/kg for pesticides and 0.3 to 200 mu g/kg for PAHs; also, the determination coefficient, R-2, was better than 0.995 in all instances. The proposed method was applied to the routine analysis of PAH and pesticide residues in virgin and refined olive oil and olive-pomace oil samples. (c) 2006 Elsevier B.V. All rights reserved.