Evaluation of different sample treatments for determining pesticide residues in fat vegetable matrices like avocado by low-pressure gas chromatography–tandem mass spectrometry

• Published in: Journal of Chromatography A Vol. 1111; no. 1; pp. 97 - 105
• Main Authors: Fernández Moreno, J.L., Arrebola Liébanas, F.J., Garrido Frenich, A., Martínez Vidal, J.L.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 07.04.2006; Elsevier
• Subjects: Avocado; Biological and medical sciences; Chemical Fractionation - methods; Chromatography, Gel - methods; Fats - chemistry; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Gas Chromatography-Mass Spectrometry - methods; GPC; Low-pressure GC; MS–MS; Persea - chemistry; Pesticide Residues - analysis; Pressure; Pressurized liquid extraction; Solvent extraction; Temperature; Vegetables - chemistry; Avocado; Pressurized liquid extraction; MS–MS; GPC; Solvent extraction; Low-pressure GC; Validation; Chemical analysis; Vegetable fat; Coupled method; Pesticides; Contamination; MS-MS; Gel permeation chromatography; Operating conditions; Gas chromatography; Multicomponent analysis; Pressure effect; Sample preparation; Residue; Mass spectrometry MS/MS; Quantitative analysis
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2006.01.108

A multi-residue method has been developed for determining 65 pesticide residues in greasy vegetable matrices such as avocado. Conventional organic solvent extraction assisted by a high-speed homogenizer was compared to pressurized liquid extraction (PLE) as extraction techniques. Following this, the lipophilic extract was purified using gel permeation chromatography (GPC). Alternative clean-up methods were also evaluated, as solid-phase extraction cartridges individually used and downstream coupled, but less effective lipophilic separation was archived. The pesticide residue determination was carried out using low-pressure gas chromatography coupled to tandem mass spectrometry (LP-GC–MS–MS), showing the applicability of this type of GC columns for the analysis of fat vegetable matrices. The proposed methodology was validated in avocado matrix. The recoveries were in the range 70–110%, with RSD values lower than 19%, at 12 and 50 μg/kg spiking levels. The limits of quantitation (LOQs) were in the range 0.04–8.33 μg/kg and the limits of detection (LODs) were between 0.01 and 2.50 μg/kg. All of them were lower than the maximum residue levels (MRLs) set by the European Union (EU) in avocado. The proposed method was evaluated analyzing pesticide residues in real avocado samples.