Characterization of polar organic compounds in the organic film on indoor and outdoor glass windows.
Organic films on an impervious surface (window glass) were sampled at paired indoor-outdoor sites in July 2000 and characterized for their paraffinic and polar organic compositions along an urban-rural transect. Four classes of polar compounds (C11-C31 aliphatic monocarboxylic, C6-C14 dicarboxylic, nine aromatic polycarboxylic, and five terpenoid acids) constituted between 81 and 95% (w/w) of the total organic fraction analyzed comprising n-alkanes (C10-C36), 46 PAH, 97 PCBs, and 18 OC pesticides. Concentrations of the polar compounds plus their precursors, n-alkanes, ranged from 8 to 124 microg m(-20 and were dominated by monocarboxylic acids (67-89%, w/w). On outdoor windows, n-alkanes, aromatic acids, and terpenoid acids decreased in concentration along the urban-rural transect. The carbon preference index values and the interpretations of individual compounds indicate that the main sources of n-alkanes were plant waxes followed by petrogenic sources; monocarboxylic and dicarboxylic acids were from plant waxes and animal fats. Results of principal component analysis showed closer correspondence between outdoor and indoor signatures than among locations. In outdoor films, these compounds are suggested to play an important role in mediating chemical fate in urban areas by air-film exchange and facilitating "wash-off" due to their surfactant-like properties. In indoor films, these compounds provide a medium for the accumulation of more toxic compounds.
Liu
Qin-Tao
QT
Environmental Chemistry Research Group, Department of Geography, University of Toronto, 100 St. George Street, Toronto, Ontario, Canada M5S 3G3.
Chen
Rachel
R
McCarry
Brian E
BE
Diamond
Miriam L
ML
Bahavar
Bagher
B
D000393:Air Pollutants / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis*; D003252:Construction Materials; D004784:Environmental Monitoring; D005898:Glass; D006838:Hydrocarbons / Q000032:analysis*; D007306:Insecticides / Q000032:analysis*; D009930:Organic Chemicals / Q000032:analysis
D000393:Air Pollutants; D006838:Hydrocarbons; D007306:Insecticides; D009930:Organic Chemicals