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Titel |
Design and construction of a simple Knudsen Effusion Mass Spectrometer (KEMS) system for vapour pressure measurements of low volatility organics |
VerfasserIn |
A. M. Booth, T. Markus, G. McFiggans, C. J. Percival, M. R. Mcgillen, D. O. Topping |
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 ; 2, no. 2 ; Nr. 2, no. 2 (2009-07-24), S.355-361 |
Datensatznummer |
250000554
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Publikation (Nr.) |
copernicus.org/amt-2-355-2009.pdf |
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Zusammenfassung |
A design of and initial results from a Knudsen Effusion Mass Spectrometer
(KEMS) are presented. The design was adapted from high temperature alloy
studies with a view to using it to measure vapour pressures for low
volatility organics. The system uses a temperature controlled cell with an
effusive orifice. This produces a molecular beam which is sampled by a
quadropole mass spectrometer with electron impact ionization calibrated to a
known vapour pressure. We have determined P(298 K) and
ΔHsub of the first 5 saturated straight chain dicarboxylic
acids: 2.15±1.19×10-2 Pa and 75±19 KJ mol−1
respectively for oxalic acid, 5.73±1.14×10-4 Pa and
91±4 KJ mol−1 for Malonic acid,
1.13±0.47×10-4 Pa and 93±6 KJ mol−1 for
Succinic acid, 4.21±1.66×10-4 Pa and
123±22 KJ mol−1 for Glutaric acid and
6.09±3.85×10-6 Pa and 125±40 KJ mol−1 for
Adipic acid. |
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