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Analysis of PM10 using Scanning Electron
Microscopy Comparison between a Traffic Site and
a Forest Site
S. Wagener1, J.K. Gietl, O. Klemm University of
Münster, Institute of Landscape Ecology,
Germany 1now IUTA Duisburg e.V.
Poster T10A042P Session PMx / PM10 /
PM2.5 Corresponding author Otto Klemm2
Introduction Airborne
atmospheric particulate material with a diameter
lt 10 µm (PM10) was collected on 12 days between
November 2006 and January 2007 at a traffic site
in Münster, and a forest site in the
Eggegebirge mountain range (NW Germany). The
measurements were performed synchronously twice
per day. About 3000 individual particles were
analyzed for morphology and element contents
applying SEM-EDX.
Method and Analysis Five-stage Berner type
impactors with aluminium and Tedlar foils were
used for sampling. Single particle analysis was
carried out by using a scanning electron
microscopy, type JEOL 840 for morphology, and
energy dispersive X-ray (EDX) spectrometry for
element contents. Based on the element analysis,
particles were assigned to groups. The percentage
of each group of the whole of all analysed
particles was computed. With the morphology and
the correlations between the percentages of all
groups, the particle groups were identified.

• Results
• The identified particle groups are
• soot
• C-residual
• sea salt
• sodium-rich

• sulphate
• iron-rich
• silicate-rich
• oxygen-rich

M Measurements the same lettering
represents simultaneous measurements
Percental composition of particulate material
as function of impactor stages
Source Identification Using the information from
these results and the morphology, source
identification could be performed.
Possible sources of the identified particle groups
Münster Eggegebirge
soot traffic, domestic fuel domestic fuel, (traffic)
C-residual presumably traffic, domestic fuel unknown, presumably traffic, domestic fuel
sea salt seaspray, other unknown anthropogenic sources seaspray
Na-rich seaspray, combustion of biomass, other unknown anthropogenic sources seaspray
sulphate (mainly (NH4)2SO4) agriculture, traffic agriculture
Fe-rich soil dust, resuspension, combustion, traffic soil dust, resuspension
Si-rich soil dust, resuspension, combustion, traffic soil dust, resuspension
O-rich presumably NH4NO3 unknown sources
Fresh soot (Münster)
Aged soot (Eggegebirge)
Fresh sea salt (Eggegebirge)
Aged sea salt (Münster)
Examples of particles analysed with the SEM
To investigate the different influences on
particle composition, the aerosol was analysed
regarding the following aspects Influence of
the air masses A correlation between sea salt and
air masses of marine origin is found at both
measurement sites Influence of the time of
day Iron-rich and silicate-rich particle
occurrence are higher in the afternoon Influence
of the location Soot and oxygen-rich particles
are much more abundant at the traffic site,
sodium-rich particles in the Eggegebirge Influenc
e of the particle size The most obvious
difference has been found between the impactor
stages whereas the first two stages (smallest
particles) are dominated by soot and sulphate,
all groups are found in stages 3 and 4 (stage 5
has not been analysed)
Conclusions The sampling location, the time of
day and the air masses essentially affect the
percental allocation of the aerosol composition.
The appearance of the particle groups is mainly
determined by the different stages. Thus it
appears, that the largest differences of particle
composition is affected rather by the different
size classes than by any other aspects.
For this study, data access was granted by
the Landesamt für Natur, Umwelt und
Verbraucherschutz NRW. Equipment access was
granted by the Institute for Planetology,
University of Münster, especially with the help
of Thorsten Grund. For further information please
contact 2otto.klemm_at_uni-muenster.de.
European Aerosol Conference, 24 29. August
2008 Helexpo Thessalonike, Greece