Abstract: In the atmosphere, exchanges between the gas and particle phases has a profound influence on the removal processes and residence times of semi-volatile compounds. This study describes analytical procedures for the reliable quantitation of both gas and particle phase azaarenes (two-, three- and four-rings). Samples of particulate material were collected on the glass fiber filters and gas phase material on polyurethane foam plugs. Azaarene compounds were isolated utilizing an acid/base partition method. Isolated azaarenes compounds were then characterized and quantified using gas chromatography with mass spectrometry (GC/MS). The analytical method described in this paper is the first procedure for the simultaneous determination of gas and particle phase azaarenes and allows 47 azaarene compounds to be reliably quantified despite the complexity of urban aerosols.