IDENTIFICATION OF POLYCYCLIC AROMATIC-HYDROCARBONS OF THE PARTICULATEACCUMULATED IN THE TUNNEL DUCT OF FREEWAY AND GENERATION OF THEIR OXYGENATED DERIVATIVES

Organic compounds of particulates accumulated in the tunnel duct of fr eeways were extracted with a benzene-ethanol mixture solution (4 : 1, v/v) and fractionated into four fractions by 5% hydrous silica gel. Th e obtained organic substances were found to be composed of nonpolar, s emipolar, polar and high polar compounds, by the use of GC-MS. The non polar fraction, in which linear alkanes ranging from C-16 to C-26 domi nated, was shown to have many peaks on an extremely broad peak by GC-M S. These notable patterns were similar to those of vehicular exhausts. These observations have been characteristic of GC patterns of vehicul ar exhausts. The semipolar fraction was identified to contain mainly t hree- to four-ring polycyclic aromatic hydrocarbons (PAHs) such as phe nanthrene, dibenzothiophene, fluoranthene, pyrene and chrysene/triphen ylene. Their concentrations in the total mass of particulates showed 0 .6-39.5 mu g/g. Moreover, alkylated PAHs such as benzo[b]naphtho [2,1- d] thiophene and cyclopenta[cd] pyrene also detected in the sample, mi ght be used for the markers of automobile exhaust particulates. In thi s fraction, 64 PAHs were tentatively identified by the use of the Wile y library search system and some of them were identified finally in co mparison with authentic samples by GC-MS. The polar fraction was found to include oxygenated polycyclic aromatic compounds such as 1-naphtha ldehyde, phenanthrene-9-carboxaldehyde, 9-fluorenone, xanthone, benzan throne, anthraquinone, 9,10-phenanthrenequinone, 2-methylanthraquinone and 1,2-benzanthraquinone. Their concentrations ranged 0.9-51.7 mu g/ g in the total mass of particulates and were higher than those of oxyg enated PAHs in particulates collected in a rural area, urban air and i ndoor air. In this fraction, 44 oxygenated compounds including oxygena ted polycyclic aromatic compounds were tentatively identified by the s ame technique described above. The high polar fraction could not be an alyzed.