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38.
Single particle analysis of standard soot samples for fast determination
of EC/OC values
T.
Ferge(1), E. Karg(2), M. Frank(3) and
R. Zimmermann(1,4,5)
(1)GSF
Forschungszentrum, Institut für Ökologische Chemie,
Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
(2)GSF Forschungszentrum, Institut für Inhalationsbiologie,
Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
(3)Lawrence Livermore National Laboratory, Physics and Advanced
Technologies Directorate, Livermore, 94550, CA
(4)BIfA-Bayerisches Institut für Angewandte Umweltforschung
und -technik GmbH, Abteilung Umweltchemie und Prozessanalytik,
Am Mittleren Moos 46, D-86167 Augsburg, Germany
(5)Analytische Chemie, Institut für Physik, Universität
Augsburg, Universitätsstraße 1, D-86159 Augsburg, Germany
Keywords:
ATOFMS, EC/OC, standard soot particles
INTRODUCTION
Standard soot particles are a valuable tool for animal exposition
experiments in order to investigate particle related health effects.
The characterization of standard particles and the comparison
with ambient aerosols as well as reference materials is a requisite
for a deeper understanding of possible inflammatory responses
of the organism exposed. For example, the ratio EC/OC is considered
to be an important factor for health effects. Aerosol time-of-flight
mass spectrometry (ATOFMS)(1,2) was tested for its application
for fast and sensitive analysis of EC/OC ratios.
METHODS
Soot samples were produced using standard generation techniques.
The samples were aerosolized and introduced into an aerosol time-of-flight
mass spectrometer. First, the particles were tracked by two sizing
lasers in order to obtain size information via the particle velocity.
Subsequently, particles were hit by an Nd:YAG laser and ionized.
Formed ions were analyzed in a time-of-flight mass spectrometer.
RESULTS
Figure 1 shows spectra of diffusion flame soot particles, which
were generated under different conditions. The OC content was
controlled by the oxygen supply in the flame. The spectra are
dominated by the typical carbon cluster peaks Cx+. However, in
samples, which should exhibit a high OC content, additional peaks
emerge between the c-cluster. These peaks can be assigned as OC,
because inorganic compounds can be excluded as (i) no Na+, K+
is visible and (ii) due to the used generation procedure of the
particles).
ACKNOWLEDGEMENTS
This study was carried out in the scope of the GSF-Focus-Network
“Aerosols and Health” which co-ordinates aerosol-related
research within the GSF Research Centre. T.F. thanks the Deutsche
Bundesstiftung Umwelt for a PhD scholarship. Funding from the
Bavarian Californian Technology Center (BaCaTeC) is gratefully
acknowledged.
REFERENCES
(1) Suess et al., Chem. Rev. (1999) 99, 3007-3035.
(2) Zimmermann et al., Rapid Comm. Mass Spectrom. (2003) 17, 851-859.
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