Determination of Pesticides and PCBs in Virgin Olive Oil by Multicolumn Solid-Phase Extraction Cleanup Followed by GC-NPD/ECD and Confirmation by Ion-Trap GC−MS

Abstract

A multicolumn solid-phase extraction cleanup for the determination of organophosphorus (OP) and organochlorine (OC) pesticides plus PCB congeners in virgin olive oil is presented. The method involves dissolution of the olive oil in hexane, followed by a cleanup system using a diatomaceous earth column (Extrelut-QE) with reversed (C(18)) and normal (alumina) phase SPE columns. Determination of OPs was by GC-NPD, while the OCs and PCBs were analyzed using GC-ECD. Recovery assays for OPs varied from 81.7% to 105.3%, for OCs ranged between 74.3% and 99.4%, while for PCBs were from 60.1% to 119.2%. Quantitation limits ranged from 10 to 25 microg/kg olive oil for OPs, and from 1 to 6 microg/kg olive oil for OCs and PCBs. In the case of positive samples, the confirmation of pesticide identity was performed by ion-trap GC-MS/MS. The applicability of the method was assayed with 19 virgin olive oil samples collected from different olive mills of Aragón (Spain). Only one OP pesticide (acephate) was detected in one sample at a concentration of 10 microg/kg. Organochlorine pesticides were found in 5-47% of samples at very low levels ranging from 1.5 to 5.2 microg/kg. PCBs were found in 20-90% of samples, showing concentrations between 2.3 and 17.3 microg/kg.

A preliminary study of PCBs, PAHs, pesticides and trace metals contamination in cold-pressed rapeseed oils from conventional and ecological cultivations

“…Overall, all samples analysed for target pesticides contained no detectable residues, only the sum of DDT isomers showed detectable amounts of pesticide residues, which was in agreement with previously published reports (Jankowski and Obiedziński 2000;Yagüe et al 2005). Moreover, no effect of seeds cultivation method on the level of pesticide residues was found.…”

Pesticide Residue Analysis in Animal Origin Food: Procedure Proposal and Evaluation for Lipophilic Pesticides

“…Clean-up step is d-SPE based on QuEChERS method for fatty samples [20][21][22][23][24][25][26][27][28][29][30]38]. 8 mL of the defatted extract is introduced in a 15 mL polypropylene centrifuge tube containing 1,200 mg MgSO4, 400 mg end-capped C18 and 400 mg PSA.…”

“…[12][13], solid phase micro-extraction [14], matrix solid phase dispersion [15] and supercritical fluid extraction [16]; (ii) clean-up by normal phase liquid chromatography (NPLC) [17] and/or gel permeation chromatography (GPC) [18][19], solid phase extraction (SPE) [20][21], and dispersive solid phase extraction (d-SPE) [22]; (iii) concentration according to analytical technique. In recent years, QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) methodology (used for extraction and clean-up steps) has been applied with success on several non-fatty (< 2 %) food matrices such fruits and vegetables [23][24] and low-fatty (2-20 %) food matrices, such milk, egg and avocado [25].…”

Aspectos toxicológicos e ocorrência dos bifenilos policlorados em alimentos

“…Porém, comparando-se com o estudo realizado na China, o valor apresenta-se inferior (XING et al, 2009). Suplementos alimentares a base de óleo de fígado de bacalhau e azeite de oliva virgem também foram analisados na Espanha, constatando-se uma alta concentração de PCBs (YAGÜE et al, 2005;MARTÍ et al, 2010).…”