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| Titel |
Characterization of a thermodenuder-particle beam mass spectrometer system for the study of organic aerosol volatility and composition |
| VerfasserIn |
A. E. Faulhaber, B. M. Thomas, J. L. Jimenez, J. T. Jayne, D. R. Worsnop, P. J. Ziemann |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 2, no. 1 ; Nr. 2, no. 1 (2009-02-10), S.15-31 |
| Datensatznummer |
250000424
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| Publikation (Nr.) |
 copernicus.org/amt-2-15-2009.pdf |
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| Zusammenfassung |
| This paper describes the development and evaluation of a method for
measuring the vapor pressure distribution and volatility-dependent mass
spectrum of organic aerosol particles using a thermodenuder-particle beam
mass spectrometer. The method is well suited for use with the widely used
Aerodyne Aerosol Mass Spectrometer (AMS) and other quantitative aerosol mass
spectrometers. The data that can be obtained are valuable for modeling
organic gas-particle partitioning and for gaining improved composition
information from aerosol mass spectra. The method is based on an empirically
determined relationship between the thermodenuder temperature at which
50% of the organic aerosol mass evaporates (T50) and the organic
component vapor pressure at 25°C (P25). This approach avoids the
need for complex modeling of aerosol evaporation, which normally requires
detailed information on aerosol composition and physical properties.
T50 was measured for a variety of monodisperse, single-component organic
aerosols with known P25 values and the results used to create a
logP25 vs. T50 calibration curve. Experiments and simulations were
used to estimate the uncertainties in P25 introduced by variations in
particle size and mass concentration as well as mixing with other
components. A vapor pressure distribution and volatility-dependent mass
spectrum were then measured for laboratory-generated secondary organic
aerosol particles. Vaporization profiles from this method can easily be
converted to a volatility basis set representation, which shows the
distribution of mass vs. saturation concentration and the gas-particle
partitioning of aerosol material. The experiments and simulations indicate
that this method can be used to estimate organic aerosol component vapor
pressures to within approximately an order of magnitude and that useful
mass-spectral separation based on volatility can be achieved. |
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