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| Titel |
Improved mid-infrared cross-sections for peroxyacetyl nitrate (PAN) vapour |
| VerfasserIn |
G. Allen, J. J. Remedios, D. A. Newnham, K. M. Smith, P. S. Monks |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 5, no. 1 ; Nr. 5, no. 1 (2005-01-17), S.47-56 |
| Datensatznummer |
250002205
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| Publikation (Nr.) |
 copernicus.org/acp-5-47-2005.pdf |
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| Zusammenfassung |
| Absorption spectra of peroxyacetyl nitrate (PAN, CH3C(O)OONO2)
vapour at room temperature (295K) have been measured in the mid-infrared
range, 550-2200cm-1 (18.2-4.55µm), using a Fourier Transform
infrared spectrometer at instrument resolutions of 0.25 and 0.03cm-1
(unapodised). Between five and eight measurements were obtained for each
spectral band of PAN in the pressure range 0.24-2.20mb showing good
agreement with Beer's law. Both cross-section data and integrated absorption
intensities for the five principal bands in the PAN spectra in this spectral
range have been derived with peak cross-sections of the 794, 1163, 1302,
1741 and 1842cm-1 bands measured to be 0.95(±0.02), 1.21(±0.03),
0.92(±0.02), 2.39(±0.06) and 0.74(±0.03) (x10-18cm2molecule-1)
respectively. Band intensities and
band centre absorptivities are also reported for four weaker PAN absorption
bands in the mid infrared for the first time. These observations are the
highest spectral resolution measurements of PAN bands reported in the
infrared to date. For three of the five strongest bands, the absolute
integrated absorption intensities are in excellent agreement with previous
studies. A 4.8% lower integrated intensity was found for the 1741cm-1νas(NO2)
PAN absorption band, possibly as a result of the
removal in this work of spectra affected by acetone contamination, while a
10.6% higher intensity was determined for the 1163cm-1ν(C-O)
absorption band. No resolution of fine structure in the PAN absorption bands
was observed at the resolutions studied. The confirmation of absorption
cross-sections and estimated errors in this work will allow more accurate
investigations of PAN using infrared spectroscopy, particularly for remote
sensing of PAN in the atmosphere. |
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