Determination of phase-distributed PAH in Rome ambient air by denuder/GC-MS method

An annular denuder—filter sampler has been tested for determination of both gaseous and particulate polycyclic aromatic hydrocarbons (PAH) in air. Collection efficiency and capacity over 6-h sampling at an air flow rate of 6 l min−1 were assessed. Concentrations were measured and phase distributions of the most important 2–6 ring PAH in air samples collected in downtown Rome during November 2002 to April 2003 were determined. The 2- and 3-ring PAH were found for more than 90% in the gas phase, whilst congeners with more than 4 rings were present almost entirely in the particle phase. Comparison with a high-volume filter—PUF sampler showed that similar results for total PAH contents (gas + particle) were observed only for congeners with molecular mass higher than 178 (phenanthrene and anthracene).