Available online at www.sciencedirect.com Talanta 75 (2008) 284–293 Comparison of four extraction methods for the analysis of 24 pesticides in soil samples with gas chromatography–mass spectrometry and liquid chromatography–ion trap–mass spectrometry C. Lesueur a,b , M. Gartner a , A. Mentler c , M. Fuerhacker b,∗ a Gartner & LVA GmbH, Blaasstrasse 29, 1190 Vienna, Austria b BOKU-University of Natural Resources and Applied Life Sciences, Institute of Sanitary Engineering and Water Pollution Control, Muthgasse 18, 1190 Vienna, Austria c BOKU-University of Natural Resources and Applied Life Sciences, Institute of Soil Research, Peter Jordanstrasse 82, 1190 Vienna, Austria Received 11 June 2007; received in revised form 9 October 2007; accepted 7 November 2007 Available online 19 November 2007 Abstract With a view to analyse multiresidues of pesticides in soil samples, a new ultrasonic solvent extraction (USE) was compared to the European Norm DIN 12393 for foodstuff (extraction with acetone, partitioning with ethylacetate/cyclohexane and clean-up with gel permeation chromatography (GPC)), the QuECheRS method and a pressurised liquid extraction (PLE) method. Pesticides were analysed with both GC-MS and HPLC-MS/MS. The reference materials were the EUROSOIL 7 and its subsoil SO26 as well as a sea sand. All the substances were observed to be linear in the range of 4–800 ng g -1 for the European Norm DIN 12393, 7–1400 ng g -1 for the USE method and 20–4000 ng g -1 for the QueCheRS and the PLE methods. Limits of detection (LOD) and limits of quantification (LOQ) were with HPLC between 0.006 and 0.23 ng g -1 and between 0.022 and 0.77 ng g -1 , respectively, with the exception of diuron (LOD up to 11.8 ng g -1 ; LOQ up to 39.2 ng g -1 ). With GC they ranged from 3.0 to 87.5 ng g -1 and from 10 to 292 ng g -1 , respectively. All substances could be recovered with USE as well as with the QuECheRS method; the European Norm DIN 12393 could not recover carbendazim and metamitron; the PLE carbendazim, metamitron and monolinuron. For the remaining substances, recoveries at a 500 ng g -1 fortification level ranged from 10.9 to 96.3% with the USE. In comparison, the QuECheRS method was the most efficient extraction method with recoveries from 27.3 to 120.9%. It was followed by the European Norm DIN 12393 with recoveries between 6.8 and 108.1% and the PLE with recoveries from 12.2 to 153.2%. Recoveries were higher from the EUROSOIL 7 than from the SO 26. The repeatability expressed in term of standard deviation was below 20% for all substances and all materials. © 2007 Elsevier B.V. All rights reserved. Keywords: Pesticides; Soil; Gas chromatography; Liquid chromatography; Mass spectrometry 1. Introduction The increasing worldwide need for food demands a higher agricultural productivity, which can only be achieved by an extensive use of pesticides. Unfortunately pesticides contami- ∗ Corresponding author. Tel.: +43 1 36006 5821; fax: +43 1 36899 49. E-mail address: maria.fuerhacker@boku.ac.at (M. Fuerhacker). nate the environment through intensive or inappropriate use [1]. Although organochlorine insecticides like DDT and its metabo- lites, lindane, aldrin or dieldrin for instance have been banned years ago in many countries based on their mutagenic, car- cinogenic and endrocrine disrupting properties, they still can be found in environmental samples due to their persistence and lipophilic properties [2–6]. Organophosphorus insectices (like chlorpyrifos, chlorpyrifos-methyl or chlorfenvinphos) and tri- azine herbicides (like atrazine, simazine, metribuzine) are the 0039-9140/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.talanta.2007.11.031