Use of annular denuders for monitoring gaseous atmospheric PAH in Rome

An annular denuder sampling system coupled with GC-MS detection has been used to separately determine gaseous and particulate PAH in Rome ambient air. Concentrations and phase distributions were obtained for 2similar to6 ring PAH. 2- and 3-ring PAH were found for more than 90% in the gas phase, whereas PAH with more than 4 rings were mostly associated with the particle phase. The predominant PAH were naphthalene and methylnaphthalenes, observed in the gas phase in the 300similar to3000 and 200similar to1000 ng m(-3) concentration ranges, respectively. The other gaseous PAH reached concentrations one or two orders of magnitude lower.