GAS-CHROMATOGRAPHY FOURIER-TRANSFORM INFRARED STUDIES OF GAS-PHASE POLYNUCLEAR AROMATIC-HYDROCARBONS

Gas chromatography/Fourier transform infrared spectra of 33 polynuclear aromatic hydrocarbons (PAHs) were measured. A PAH gas-phase infrared spectral library has been created to include these 33 PAHs for the identification and isomeric differentiation of PAH-containing environmental samples. A literature survey indicated that for most of these PAHs, this is the first time that their gas-phase infrared spectra have been measured. Based on infrared group frequencies of benzene, naphthalene and several PAHs with high molecular symmetry, band assignments in the spectral region 680-4000 cm-1 for these PAHs have been attempted. The aromatic C-H out-of-plane and C-C in-plane bending modes in the spectral region 680-900 cm-1 demonstrate a unique spectral feature for each PAH. The possibility of distinguishing among a group of isomers using the information from this region is demonstrated.