Measurement of Organic Compounds in Diesel and Gasoline Engine Exhaust using Thermal Desorption PTR-MS
Abstract
A proton transfer reaction mass spectrometer modified with a thermal desorption sampler was used to measure organic compounds in diesel and gasoline engine exhaust in a laboratory setting. The drift tube was operated at 80 Td, providing an M+1 and M-1 mass spectrum for the most abundant constituents of the exhaust including alkenes, cycloalkanes, bicycloalkanes, monoaromatics, and naphthenic monoaromatic compounds. Alkanes were observed to fragment to a common set of ions. Use of the thermal desorption sampler enabled the total concentration of C10-C17 alkanes to be determined. The abundance of higher molecular weight cycloalkanes, bicycloalkanes, napthenic monoaromatics, and larger C10-C17 alkanes was much greater in diesel exhaust, allowing for a distinct source fingerprint pattern to distinguish diesel from gasoline exhaust. Use of the finger print source profiles allowed us to quantify the relative amounts of diesel and gasoline exhaust in mixtures, suggesting its utility to determine the relative contributions of gasoline and diesel engine exhaust to hydrocarbon concentrations in urban areas.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.A31C0068J
- Keywords:
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- 0345 ATMOSPHERIC COMPOSITION AND STRUCTURE Pollution: urban and regional;
- 0365 ATMOSPHERIC COMPOSITION AND STRUCTURE Troposphere: composition and chemistry