Journal ArticleDOI
The Influence of Experimental Conditions in Quantitative Analysis of Powdered Samples by Fourier Transform Infrared Photoacoustic Spectroscopy
J. G. Highfield,J. B. Moffat +1 more
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TLDR
In this article, the Fourier Transform Infrared Photoacoustic Spectroscopy (FT-IR/PAS) was used to obtain optical absorption spectra from strongly scattering and/or opaque materials which are difficult to study by conventional photometric methods.Abstract:
Photoacoustic Spectroscopy (PAS) is now well-established as a useful technique for obtaining optical absorption spectra from strongly scattering and/or opaque materials which are difficult to study by conventional photometric methods. However, its quantitative application to solids in the UV-visible region has been somewhat restricted by the phenomenon of photoacoustic (PA) signal saturation, in which the intensity of the stronger bands in the spectrum becomes insensitive to changes in analyte concentration. By comparison, with the recent advent of Fourier Transform Infrared Photoacoustic Spectroscopy (FT-IR/PAS), this problem is expected to be much less serious in view of the low absorptivities characteristic of IR bands. Indeed, recent work in our laboratory has shown that when NH3 is sorbed stepwise into the bulk of 12-tungstophosphoric acid, H3PW12O40, the base is quantitatively converted to NH4+ ion, and the calibration curve of the analyte peak area (standardized against a reference band of the substrate) vs. analyte concentration is virtually linear up to stoichiometric loading. With the use of this method, several salts of the parent acid were found to exist in partial (Bronsted) acid form, and adjusted molecular formulae thus calculated were consistent with those obtained in dependently by elemental analysis.read more
Citations
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Theoretical and practical aspects of short open tubular columns at subambient pressures in gas chromatography/mass spectrometry
Mark E. Hail,Richard A. Yost +1 more
Journal ArticleDOI
Diffuse-reflectance Fourier-transform infrared spectroscopic studies of the stability of aluminum nitride powder in an aqueous environment
James Highfield,Paul Bowen +1 more
Journal ArticleDOI
Catalysis by solid state oxometalates
TL;DR: In this article, the presence of protons is shown to be essential for the oxidation process, evidently assisting in the production of oxygen vacancies, the precursor to the formation of carbon-carbon linkages.
References
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Journal ArticleDOI
An infrared study of pyridine adsorbed on acidic solids. Characterization of surface acidity
TL;DR: In this article, the infrared spectrum of pyridine coordinately bonded to the surface of acid solids has been determined and a rough estimate of the strength of surface Lewis sites can be inferred.
Book
Advances in Infrared and Raman Spectroscopy
R. J. H. Clark,R. E. Hester +1 more
TL;DR: A Unified View of Raman, Resonance Raman and Fluorescence Spectroscopy (and their Analogues in Two-Photon Absorption) Magnetic Raman Optical Acitivity as mentioned in this paper The resonance Raman Effect and Depolarization in Vibrational Raman Scattering Low Frequency Depolarized Light Scattering from Liquids and Solutions
Book
Photoacoustics and Photoacoustic Spectroscopy
TL;DR: The recognized leader in the modern development of the field presents both theory and applications as mentioned in this paper, and provides a comprehensive survey of applications, from spectroscopy and chemistry analysis to medical applications and thermal analysis.
Journal ArticleDOI
The Structure and Formula of 12-Phosphotungstic Acid
TL;DR: In this article, it was shown that one atom of such elements as P, Si, As, B, Al, etc., is combined with a number of atoms of an element such as W or Mo, together with a relatively large number of oxygen.