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| Titel |
Incoherent broadband cavity-enhanced total internal reflection spectroscopy of surface-adsorbed metallo-porphyrins |
| VerfasserIn |
A. A. Ruth, G. Glaczynski, K. T. Lynch |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250030154
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| Zusammenfassung |
| An improvement of conventional attenuated total reflection (ATR) spectroscopy is
demonstrated by applying an incoherent broadband light source (short-arc Xe-lamp) in a
cavity-enhanced evanescent-wave absorption method. With this novel approach the
absorption spectra of several metallo-octaethyl porphyrins (Palladium (PdOEP), Platinum
(PtOEP) and Zinc- (ZnOEP)) in thin acetone solution layers and on a fused silica (FS) surface
were studied between 390 and 625 nm. The time dependence of the evaporation process of
the solution on the FS surface is described. The maximum sensitivity of the setup is estimated
at approximately 2 Ã 10-5 per pass, which translates into a minimal detectable surface
density of less than 2 Ã 10-3 monolayers for the porphyrins studied (based on
absorption in the strong Soret bands). Changes of surface and solution spectra are
characterised and discussed on basis of observed band broadenings and spectral
shifts.
This new approach is of relevance for investigations in atmopsheric and planetary
sciences involving absorbers on surfaces and heterogeneous chemistry. |
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