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| Titel |
The ToF-ACSM: a portable aerosol chemical speciation monitor with TOFMS detection |
| VerfasserIn |
R. Fröhlich, M. J. Cubison, J. G. Slowik, N. Bukowiecki, A. S. H. Prévôt, U. Baltensperger, J. Schneider, J. R. Kimmel, M. Gonin, U. Rohner, D. R. Worsnop, J. T. Jayne |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 6, no. 11 ; Nr. 6, no. 11 (2013-11-26), S.3225-3241 |
| Datensatznummer |
250085116
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| Publikation (Nr.) |
 copernicus.org/amt-6-3225-2013.pdf |
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| Zusammenfassung |
| We present a new instrument for monitoring aerosol composition, the
time-of-flight aerosol chemical speciation monitor
(ToF-ACSM), combining precision state-of-the-art
time-of-flight mass spectrometry with stability, reliability, and
easy handling, which are necessities for long-term monitoring
operations on the scale of months to years. Based on Aerodyne
aerosol mass spectrometer (AMS) technology, the ToF-ACSM provides
continuous online measurements of chemical composition and mass of
non-refractory submicron aerosol particles. In contrast to the
larger AMS, the compact-sized and lower-priced ToF-ACSM does not
feature particle sizing, similar to the widely-used quadrupole-ACSM
(Q-ACSM). Compared to the Q-ACSM, the ToF-ACSM features a better
mass resolution of M/ΔM = 600 and better detection
limits on the order of < 30 ng m−3 for a time
resolution of 30 min. With simple upgrades these limits can be
brought down by another factor of ~ 8. This allows for
operation at higher time resolutions and in low concentration
environments. The associated software packages (single packages for
integrated operation and calibration and analysis) provide a high
degree of automation and remote access, minimising the need for
trained personnel on site. Intercomparisons with Q-ACSM, C-ToF-AMS,
nephelometer and scanning mobility particle sizer (SMPS)
measurements, performed during a first long-term deployment (> 10
months) on the Jungfraujoch mountain ridge (3580 m a.s.l.) in the
Swiss Alps, agree quantitatively. Additionally, the mass resolution
of the ToF-ACSM is sufficient for basic mass defect resolved peak
fitting of the recorded spectra, providing a data stream not
accessible to the Q-ACSM. This allows for quantification of certain
hydrocarbon and oxygenated fragments (e.g. C3H7+ and
C2H3O+, both occurring at m/Q = 43 Th), as well as
improving inorganic/organic separation. |
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