Determination of pesticide residues in olive oil and olives

Pesticide-residue determination in olive oil is becoming a very important and challenging issue. The present article provides a review of the most significant methods for determining pesticides in olive oil. The discussion of sample-treatment procedures is focused on not only the final product (olive oil), but also the direct analysis of the raw material (olive fruits). We outline extraction and clean-up procedures (e.g., liquid-liquid partition, gel-permeation chromatography (GPC), solid-phase extraction (SPE), matrix solid-phase dispersion (MSPD) and Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS). However, we pay specially attention to the clean-up stage, which plays an important role in the whole process. In addition, identification and quantitation of pesticides have been carried out by gas chromatography (GC) coupled to different detectors (flame-ionization (FID), nitrogen-phosphorus (NPD) and electron-capture (ECD), although either GC-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode or GC-tandem MS (GC-MS2) are becoming the combination of choice, because of higher selectivity and confirmation capabilities. In recent years, the appearance of new, more polar pesticides has prompted the use of liquid chromatography-MS (LC-MS) instead of GC-MS, and we outline its advantageous features for the analyses of polar pesticides in olive oil. (c) 2007 Elsevier Ltd. All rights reserved.