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Published March 15, 2002 | public
Journal Article

Measurement of Emissions from Air Pollution Sources. 5. C_1−C_(32) Organic Compounds from Gasoline-Powered Motor Vehicles


Gas- and particle-phase organic compounds present in the tailpipe emissions from an in-use fleet of gasoline-powered automobiles and light-duty trucks were quantified using a two-stage dilution source sampling system. The vehicles were driven through the cold-start Federal Test Procedure (FTP) urban driving cycle on a transient dynamometer. Emission rates of 66 volatile hydrocarbons, 96 semi-volatile and particle-phase organic compounds, 27 carbonyls, and fine particle mass and chemical composition were quantified. Six isoprenoids and two tricyclic terpanes, which are quantified using new source sampling techniques for semi-volatile organic compounds, have been identified as potential tracers for gasoline-powered motor vehicle emissions. A composite of the commercially distributed California Phase II Reformulated Gasoline used in these tests was analyzed by several analytical methods to quantify the gasoline composition, including some organic compounds that are found in the atmosphere as semi-volatile and particle-phase organic compounds. These results allow a direct comparison of the semi-volatile and particle-phase organic compound emissions from gasoline-powered motor vehicles to the gasoline burned by these vehicles. The distribution of n-alkanes and isoprenoids emitted from the catalyst-equipped gasoline-powered vehicles is the same as the distribution of these compounds found in the gasoline used, whereas the distribution of these compounds in the emissions from the noncatalyst vehicles is very different from the distribution in the fuel. In contrast, the distribution of the polycyclic aromatic hydrocarbons and their methylated homologues in the gasoline is significantly different from the distribution of the PAH in the tailpipe emissions from both types of vehicles.

Additional Information

© 2002 American Chemical Society. Received for review March 30, 2001. Revised manuscript received December 3, 2001. Accepted December 5, 2001. We thank Rapheal Susnowitz, Thu Vo, Pons Lazo, and the staff at the California Air Resources Board's Haagen-Smit Laboratory in El Monte, CA, for their assistance and cooperation in conducting the dynamometer source tests; Eric Grosjean and Daniel Grosjean (DGA, Inc.) for preparation and analysis of the C_(18) cartridges used for carbonyls; Rei Rasmussen (Oregon Graduate Institute) for preparation and analysis of the SUMA canisters used for measurement of C_(10) and smaller vapor-phase hydrocarbons; Judy Chow and Cliff Frazier at the Desert Research Institute for X-ray fluorescence measurements; Bob Cary at Sunset Labs for EC/OC measurements; and Lynn Salmon (Caltech) for conducting the ion chromatography, colorimetry, and atomic absorption spectroscopy analyses. This research was supported by the California Air Resources Board under Agreement A93-329.

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