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| Titel |
Enhancing non-refractory aerosol apportionment from an urban industrial site through receptor modeling of complete high time-resolution aerosol mass spectra |
| VerfasserIn |
M. L. McGuire, R. Y.-W. Chang, J. G. Slowik, C.-H. Jeong, R. M. Healy, G. Lu, C. Mihele, J. P. D. Abbatt, J. R. Brook, G. J. Evans |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 14, no. 15 ; Nr. 14, no. 15 (2014-08-13), S.8017-8042 |
| Datensatznummer |
250118938
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| Publikation (Nr.) |
 copernicus.org/acp-14-8017-2014.pdf |
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| Zusammenfassung |
Receptor modeling was performed on quadrupole unit mass resolution aerosol mass spectrometer (Q-AMS) sub-micron
particulate matter (PM) chemical speciation measurements from Windsor,
Ontario, an industrial city situated across the Detroit River from Detroit,
Michigan. Aerosol and trace gas measurements were collected on board
Environment Canada's Canadian Regional and Urban Investigation System for
Environmental Research (CRUISER) mobile laboratory. Positive matrix factorization (PMF) was performed
on the AMS full particle-phase mass spectrum (PMFFull MS)
encompassing both organic and inorganic components. This approach compared to the more common method of analyzing only the organic mass spectra (PMFOrg MS). PMF of the
full mass spectrum revealed that variability in the non-refractory sub-micron
aerosol concentration and composition was best explained by six factors: an
amine-containing factor (Amine); an ammonium sulfate- and oxygenated organic
aerosol-containing factor (Sulfate-OA); an ammonium nitrate- and oxygenated
organic aerosol-containing factor (Nitrate-OA); an ammonium
chloride-containing factor (Chloride); a hydrocarbon-like organic aerosol
(HOA) factor; and a moderately oxygenated organic aerosol factor (OOA). PMF
of the organic mass spectrum revealed three factors of similar composition to
some of those revealed through PMFFull MS: Amine, HOA and OOA.
Including both the inorganic and organic mass proved to be a beneficial
approach to analyzing the unit mass resolution AMS data for several reasons.
First, it provided a method for potentially calculating more accurate
sub-micron PM mass concentrations, particularly when unusual factors are
present, in this case the Amine factor. As this method does not rely on a
priori knowledge of chemical species, it circumvents the need for any
adjustments to the traditional AMS species fragmentation patterns to account
for atypical species, and can thus lead to more complete factor profiles. It
is expected that this method would be even more useful for HR–ToF–AMS data,
due to the ability to understand better the
chemical nature of atypical factors from high-resolution mass spectra.
Second, utilizing PMF to extract factors containing inorganic species allowed
for the determination of the extent of neutralization, which could have
implications for aerosol parameterization. Third, subtler differences in
organic aerosol components were resolved through the incorporation of
inorganic mass into the PMF matrix. The additional temporal features provided
by the inorganic aerosol components allowed for the resolution of more types
of oxygenated organic aerosol than could be reliably resolved from PMF of
organics alone. Comparison of findings from the PMFFull MS and
PMFOrg MS methods showed that for the Windsor airshed, the
PMFFull MS method enabled additional conclusions to be drawn in
terms of aerosol sources and chemical processes. While performing
PMFOrg MS can provide important distinctions between types of
organic aerosol, it is shown that including inorganic species in the PMF
analysis can permit further apportionment of organics for unit mass
resolution AMS mass spectra. |
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