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| Titel |
Real-time measurements of levoglucosan in fine aerosols (PM2.5) in the region of Paris (France) |
| VerfasserIn |
J. Sciare, N. Bonnaire, G. Mocnik, J. Nicolas, J. E. Petit, M. Bressi, R. Sarda-Estève, L. Drinovic |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250059625
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| Zusammenfassung |
| Levoglucosan - one the major monosaccharide anhydride compounds produced by the
combustion of cellulose and hemicellulose - is emitted in large amounts by wildfires or
residential wood burning (during winter months). Over the past few years, this
specific tracer has received more and more attention at it can be used in a quantitative
way to derive atmospheric concentrations of biomass burning aerosols [Favez et
al., 2010] which aerosol source has strong implications for climate and air quality
studies.
A new technique has been developed and is presented here to investigate real-time
concentrations of levoglucosan in fine aerosols (PM2.5). This technique is based on
a Particle-into-liquid-sampler (PILS, Brechtel Manufacturing inc., model 4002)
used “on-line” and coupled with an electrospray ionisation source – tandem mass
spectrometry (ESI-MS/MS, AB SCIEX model 3200 QTRAP). Air was drawn in
the PILS at 15LPM and removed from particles larger than 2.5μm aerodynamic
diameter (AD) using a very sharp cyclone. Water-soluble aerosols were collected in the
PILS and sent in the 10μl loop of the ESI-MS/MS at a flowrate of 50μl/min. Flow
injection analysis (FIA) was then performed every 2.5min for the quantification of
levoglucosan using a specific transition 161-113 m/z (negative mode), by Multiple Reaction
Monitoring (MRM) mode. An internal levoglucosan standard was injected every 10
samples (i.e. every 25min) in order to check the stability of the mass spectrometry
calibration. Field blanks were performed using a total filter upstream of the PILS
instrument and did not show any detectable amount of levoglucosan. A limit of
quantification (LOQ) better than 1 ng/m3 was calculated here for levoglucosan in FIA
mode.
Based on these settings, unattended measurements of levoglucosan by PILS-ESI-MS/MS
have been performed every 2.5 min in the region of Paris for a couple of weeks during the
winter 2011 showing concentrations ranging from below 1ng/m3 to more than 500ng/m3.
These measurements were compared to measurements of Black Carbon from wood burning
obtained in parallel every 5 min using a 7 wavelength aethalometer (Magee Scientific, models
AE31 and AE33,) and the use of the “aethalometer” model [Sandradewi et al., 2008; Sciare et
al., 2001]. A very good agreement was observed between these 2 tracers of biomass burning
aerosols, providing valuable information on the strong temporality of the domestic wood
burning source.
This new tool, in conjunction with other real-time analyzers, may offer new opportunities
to investigate the fast atmospheric processes of biomass burning aerosols which have been
reported in smog chamber studies [Grieshop et al., 2009].
References
Favez, O., et al., (2010), Inter-comparison of source apportionment models for the
estimation of wood burning aerosols during wintertime in an Alpine city (Grenoble, France),
Atmos. Chem. Phys., 10, 5295–5314, doi:10.5194/acp-10-5295-2010.
Grieshop, A. et al. (2009), Laboratory investigation of photochemical oxidation of
organic aerosol from wood fires 1: measurement and simulation of organic aerosol evolution,
Atmos. Chem. Phys., 9, 1263–1277.
Sandradewi, J., et al., (2008), Using aerosol light absorption measurements for the
quantitative determination of wood burning and traffic emission contributions to particulate
matter, Environ. Sci. Technol., 42, 3316–3323, doi:10.1021/es702253m.
Sciare, J., et al. (2011), Large contribution of water-insoluble secondary organic aerosols
in the region of Paris (France) during wintertime, J. Geophys. Res., under revision. |
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