Analysis of polycyclic aromatic hydrocarbons adsorbed on particles of atmospheric interest using pressurised fluid extraction.

Pressurised fluid extraction (PFE) was used for the measurement of 13 polycyclic aromatic hydrocarbons (PAHs) adsorbed on different types of particles: two model particles (PAH-coated silica, PAH-coated graphite) and two natural atmospheric particles (urban dust and diesel exhaust, from NIST reference materials). Samples were analysed by gas chromatography coupled to mass spectrometry. Extraction efficiency was evaluated with internal standard recovery yields and was shown to depend on the nature of the particle, on the structure of the analytes and on the PAH concentration. Extraction conditions (toluene, 130 degrees C, 130 bar, 2 x 8-min static cycles) were optimised to extract PAHs when strongly interacting with solid matrices and were validated by the analysis of two PAH-certified materials.