AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Differences in the Carbon Finger Print for Different Soot Sources
AMEWU A. MENSAH, Joel Corbin, Berko Sierau, Institute of Atmospheric and Climate Science
Abstract Number: 356 Working Group: Carbonaceous Aerosols in the Atmosphere
Abstract Soot particles significantly contribute to the total ambient aerosol particle loading. However, little is known about the chemical characteristics of soot particles originating from different soot sources. The recent development of the Soot Particle Aerosol Mass Spectrometer (SP-AMS) based on the well-known Aerodyne AMS allows analysis of soot particles in real time. As an example of a prominent ambient soot source we present the first high resolution mass spectrometric analysis of direct turbine emission soot particles sampled under controlled conditions in the turbine maintenance facility of SR Technics, Switzerland, as part of an Aircraft Exhaust Emissions Measurement Committee (E-31) campaign. We compare these results to different standard soot sources produced in the laboratory. This includes particles generated by a CAST burner under fuel-rich (brown) and fuel-lean (black) conditions, a GFG spark generator, nebulized Regal Black, and nebulized fullerene soot.
We show that the soot sources can be partly characterized by the analysis of the signal intensities of the mass to charge ratios (m/z) 12 and m/z 36. The ratio m/z 12 to m/z 36 ranges from 0.57 for CAST brown to 0.95 for CAST black. Intermediate values are determined for the other laboratory generated soot particles. Interestingly, the m/z 12 to m/z 36 ratio of a CFM56 7B airplane turbine has a value of 0.79, which is closest to the value of GFG particles (0.85). Furthermore, we present more detailed analyses of the mass spectrometric patterns such as positive matrix factorization (PMF) analysis.