Analytica Chimica Acta 583 (2007) 266–276 Characterisation of polycyclic aromatic hydrocarbons in atmospheric aerosols by gas chromatography–mass spectrometry E. Borr´ as a,∗ , L.A. Tortajada-Genaro a,b a Fundaci´ on Centro de Estudios Ambientales del Mediterr´ aneo (CEAM), 46980 Paterna, Valencia, Spain b Departamento de Qu´ımica, Universidad Polit´ ecnica de Valencia, 46022 Valencia, Spain Received 21 July 2006; received in revised form 23 October 2006; accepted 27 October 2006 Available online 18 November 2006 Abstract An accurate and reliable method for determining polycyclic aromatic hydrocarbons (PAHs) in atmospheric aerosols is described. This opti- mised gas chromatography–mass spectrometry (GC–MS) method permits a wide range of concentrations to be analysed without the influence of interferences. Pre-treatment comparison of four kinds of aerosol collector filters determined that quartz and glass fibre filters were the most suitable. Solvents like cyclohexane, toluene, acetonitrile and dichloromethane were evaluated for their PAH-extraction capacity. Ultrasonic extraction using CH 2 Cl 2 was selected because it is rapid and easy; moreover, this solvent increases the sample-throughput capacity. PAH compounds were quantitatively collected and ultrasonically extracted twice using 15 mL of CH 2 Cl 2 for 15 min for each replicate. Rotavapor concentration, fractionation and dissolution were also optimised. A certified standard mixture (16 EPA PAHs), a deuterated compound and precision recovery assays were used for validating the pro- posed methodology. Adequate analytical parameters were obtained. Detection limits were (1.6–26.3) × 10 −5 ng and quantification limits were (5.2–87.6) × 10 −5 ng. Analysis of the environmental samples detected 4-10 EPA list PAH compounds. In addition, 2–11 tentative compounds were found, and their molecular structures were described for the first time. Our study of both Youden method and the standard addition method has shown that the proposed determination of PAHs in environmental samples is free of systematic errors. In conclusion, this unbiased methodology improves the identification and quantification of PAH compounds. High sensitivity as well as acceptable detection and quantification limits were obtained for the environmental applications. © 2006 Elsevier B.V. All rights reserved. Keywords: Polycyclic aromatic hydrocarbons; Atmospheric aerosols; Gas chromatography–mass spectrometry 1. Introduction Polycyclic aromatic hydrocarbons (PAHs) are dangerous pollutants because of their carcinogenicity and genotoxicity. These compounds are generated naturally in volcanic eruptions, plant emissions and forest fires. Their anthropogenic sources include the incomplete combustion of fossil fuels and gas diesel vehicular emissions [1], domestic heating, industrial activity [2], oil heating, incinerators [3] and tobacco smoke [1]. ∗ Corresponding author at: EUPHORE department, Fundaci ´ on Centro de Estu- dios Ambientales del Mediterr´ aneo (CEAM), C/Charles R. Darwin, 14, 46980 Paterna, Valencia, Spain. Tel.: +34 96 1318227; fax: +34 96 131 8190. E-mail address: esther@ceam.es (E. Borr´ as). Atmospheric aerosol quality is one of the main concerns in the environmental policy of the European Union. Aerosols are included in the European list of atmospheric polluting agents [4]. They play an important role in the area of human health and have the potential to cause respiratory diseases [5–6]. As PAH compounds usually appear in particles smaller than 3 m, their main effect is lung cancer although they have also been linked to skin and bladder cancer [7]. Measuring PAHs by means of chemical analyses of par- ticulate matter is often time-consuming because of the high diversity of these compounds at low concentrations in ambient air. It is an analytical challenge to be able to identify most of the PAH compounds in atmospheric samples and achieve low detection and quantification limits. Studies by different 0003-2670/$ – see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.aca.2006.10.043