DETECTION OF KNOWN PHOTOCHEMICAL DECOMPOSITION PRODUCTS OF PAH IN PARTICULATE MATTER FROM POLLUTION EPISODES IN SEOUL,KOREA

Over the past two decades, significant efforts have been expended to identify the photochemical decomposition products of the OH radical reactions of various polycyclic aromatic compounds (PAC), such as naphthalene, methylnaphthalenes, acenaphthene and phenanthrene (1 Lane, D. A. and Tang, H. 1994. Photochemical degradation of polycyclic aromatic compounds. I. Naphthalene.. Polycycl. Aromat. Comp, 5(1): 131–138. Taylor & Francis Online] , Google Scholar], 2 Bunce, N. J., Liu, L., Zhu, J. and Lane, D.A. 1997. Reaction of naphthalene and its derivatives with hydroxyl radicals in the gas phase.. Environ. Sci. Technol, 31(8): 2252–2259.  Google Scholar], 3 Sasaki, J., Aschmann, S.M., Kwok, E.S.C., Atkinson, R. and Arey, J. 1997. Products of the gas-phase OH and NO3 radical-initiated reactions of naphthalene.. Environ. Sci. Technol, 31(11): 3173–3179.  Google Scholar], 4 Sauret-Szczepanski, N. and Lane, D.A. 2004. Smog chamber study of acenaphthene: Gas/particle partition measurements of the products formed by reaction with the OH radical.. Polycycl. Aromat. Comp, 24(3): 161–172. Taylor & Francis Online], Web of Science ®] , Google Scholar], 5 Banceu, C. E., Mihele, C.M., Lane, D.A. and Bunce, N.J. 2001. Reactions of methylated naphthalenes with hydroxyl radicals under simulated atmospheric conditions.. Polycycl. Aromat. Comp, 18(4): 415–426. Taylor & Francis Online], Web of Science ®] , Google Scholar], 6 Wang, L., Atkinson, R. and Arey, J. 2007. Dicarbonyl products of the OH radical-initiated reactions of naphthalene and the C1- and C2-alkylnaphthalenes.. Environ. Sci. Technol, 41(8): 2803–2810.  Google Scholar], 7 Lee, J. Y. and Lane, D.A. 2009. Unique products from the reaction of naphthalene with the hydroxyl radical. Atmos. Environ., 43: 4886–4893. Crossref] , Google Scholar]). Although these parent PAC are predominantly found in the gas phase, many of their oxidation products have been found largely in the particle phase (4 Sauret-Szczepanski, N. and Lane, D.A. 2004. Smog chamber study of acenaphthene: Gas/particle partition measurements of the products formed by reaction with the OH radical.. Polycycl. Aromat. Comp, 24(3): 161–172. Taylor & Francis Online], Web of Science ®] , Google Scholar], 7 Lee, J. Y. and Lane, D.A. 2009. Unique products from the reaction of naphthalene with the hydroxyl radical. Atmos. Environ., 43: 4886–4893. Crossref] , Google Scholar], 8 Mihele, C. M., Wiebe, H.A. and Lane, D.A. 2002. Particle formation and gas/particle partition measurements of the products of the naphthalene-OH radical reaction in a smog chamber. Polycycl. Aromat. Comp., 22: 729–736. Taylor & Francis Online], Web of Science ®] , Google Scholar]). These products include diones, hydroxy-, and nitrated products as well as many products resulting from ring-opening steps. It is, or should be, the goal of every laboratory study on atmospheric processes to apply the laboratory results to real world samples. To this end, we have obtained particulate matter air samples, as well as some smog episode samples, from Seoul Korea and have searched for the known decomposition products of the above mentioned PAC. To eliminate the use of chlorinated solvents used in the extraction and analysis of particulate matter samples, we have been utilizing the direct thermal desorption of small (4 mm diameter) punches of filters followed by Multidimensional Gas Chromatography-Time of Flight Mass Spectrometry (TD-GCxGC-TOFMS) for the analysis of the desorbed compounds. So far, we have detected 14 of the known decomposition products of naphthalene, acenaphthene and phenanthrene in the Seoul pollution episode samples. These include: 1-hydroxynaphthalene, (E) 2-formylcinnamaldehyde, phthalic anhydride, phthalide, 1,2-naphthalic anhydride, 9-hydroxyphenanthrene and dibenzopyrone.