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| Titel |
Positive matrix factorization of PM2.5 – eliminating the effects of gas/particle partitioning of semivolatile organic compounds |
| VerfasserIn |
M. Xie, K. C. Barsanti, M. P. Hannigan, S. J. Dutton, S. Vedal |
| 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 ; 13, no. 15 ; Nr. 13, no. 15 (2013-08-01), S.7381-7393 |
| Datensatznummer |
250018798
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| Publikation (Nr.) |
 copernicus.org/acp-13-7381-2013.pdf |
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| Zusammenfassung |
| Gas-phase concentrations of semi-volatile organic compounds (SVOCs) were
calculated from gas/particle (G/P) partitioning theory using their measured
particle-phase concentrations. The particle-phase data were obtained from an
existing filter measurement campaign (27 January 2003–2 October 2005) as a
part of the Denver Aerosol Sources and Health (DASH) study, including 970
observations of 71 SVOCs (Xie et al., 2013). In each compound class of SVOCs,
the lighter species (e.g. docosane in n alkanes, fluoranthene in PAHs) had
higher total concentrations (gas + particle phase) and lower
particle-phase fractions. The total SVOC concentrations were analyzed using
positive matrix factorization (PMF). Then the results were compared with
source apportionment results where only particle-phase SVOC concentrations
were used (particle only-based study; Xie et al., 2013). For the particle only-based PMF analysis, the factors primarily associated with primary or
secondary sources (n alkane, EC/sterane and inorganic ion factors) exhibit
similar contribution time series (r = 0.92–0.98) with their corresponding
factors (n alkane, sterane and nitrate + sulfate factors) in the current
work. Three other factors (light n alkane/PAH, PAH and summer/odd n
alkane factors) are linked with pollution sources influenced by atmospheric
processes (e.g. G/P partitioning, photochemical reaction), and were less
correlated (r = 0.69–0.84) with their corresponding factors (light SVOC,
PAH and bulk carbon factors) in the current work, suggesting that the source
apportionment results derived from particle-only SVOC data could be affected
by atmospheric processes. PMF analysis was also performed on three
temperature-stratified subsets of the total SVOC data, representing ambient
sampling during cold (daily average temperature <10 °C), warm
(≥10 °C and ≤20 °C) and hot
(>20 °C) periods. Unlike the particle only-based study, in this
work the factor characterized by the low molecular weight (MW) compounds
(light SVOC factor) exhibited strong correlations (r = 0.82–0.98) between
the full data set and each sub-data set solution, indicating that the impacts
of G/P partitioning on receptor-based source apportionment could be
eliminated by using total SVOC concentrations. |
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