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| Titel |
Quantification of aerosol chemical composition using continuous single particle measurements |
| VerfasserIn |
C.-H. Jeong, M. L. McGuire, K. J. Godri, J. G. Slowik, P. J. G. Rehbein, 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 ; 11, no. 14 ; Nr. 11, no. 14 (2011-07-20), S.7027-7044 |
| Datensatznummer |
250009930
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| Publikation (Nr.) |
 copernicus.org/acp-11-7027-2011.pdf |
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| Zusammenfassung |
| Mass concentrations of sulphate, nitrate, ammonium, organic carbon (OC),
elemental carbon (EC) were determined from real time single particle data in
the size range 0.1–3.0 μm measured by an Aerosol Time-of-Flight Mass
Spectrometer (ATOFMS) at urban and rural sites in Canada. To quantify
chemical species within individual particles measured by an ATOFMS, ion peak
intensity of m/z −97 for sulphate, −62 for nitrate, +18 for ammonium, +43
for OC, and +36 for EC were scaled using the number and size distribution
data by an Aerodynamic Particle Sizer (APS) and a Fast Mobility Particle
Sizer (FMPS). Hourly quantified chemical species from ATOFMS single-particle
analysis were compared with collocated fine particulate matter (aerodynamic
diameter < 2.5 μm, PM2.5) chemical composition measurements by
an Aerosol Mass Spectrometer (AMS) at a rural site, a Gas-Particle Ion
Chromatograph (GPIC) at an urban site, and a Sunset Lab field OCEC analyzer
at both sites. The highest correlation was found for nitrate, with
correlation coefficients (Pearson r) of 0.89 (ATOFMS vs. GPIC) and 0.85
(ATOFMS vs. AMS). ATOFMS mass calibration factors, determined for the urban
site, were used to calculate mass concentrations of the major PM2.5
chemical components at the rural site near the US border in southern
Ontario. Mass reconstruction using the ATOFMS mass calibration factors
agreed very well with the PM2.5 mass concentrations measured by a
Tapered Element Oscillating Microbalance (TEOM, r = 0.86) at the urban site
and a light scattering monitor (DustTrak, r = 0.87) at the rural site. In
the urban area nitrate was the largest contributor to PM2.5 mass in the
winter, while organics and sulphate contributed ~64 % of the
summer PM2.5 in the rural area, suggesting a strong influence of
regional/trans-boundary pollution. The mass concentrations of five major
species in ten size-resolved particle-types and aerosol acidity of each
particle-type were determined for the rural site. On a mass basis sulphate
and OC rich particle-types (OC-S and OC-S-N) accounted for up to 59 % of the
particles characterized and aerosols were weakly acidic in the rural area.
This is the first study to estimate hourly quantitative data of sulphate,
nitrate, ammonium, OC and EC in ambient particles from scaled ATOFMS single
particle analysis; these were closely comparable with collocated high time
resolution data of sulphate, nitrate and ammonium detected by AMS and GPIC. |
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