Talk:Thermal desorption spectroscopy
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[edit]Is TDS really only applicable to surfaces? Shouldn't it say that it can be used to analyze materials in general, even bulk? —Preceding unsigned comment added by 134.95.46.4 (talk) 10:54, 12 July 2008 (UTC)
Yes, it is certainly not limited to surfaces. The article is actually a very narrow description of the technique. Even though a mass spectrometer is flexible, and most often used in surface science, in principle any detector can be used, provided it can monitor the concentration of the adsorbate in the gas phase. Even that may be too limited: one could easily envisage methods that follow the coverage of an adsorbate on the surface. The desorption data are then derived from the decrease of the coverage. It is possible to measure Thermal Desorption for e.g. NH3 on zeolites by following the weight loss during heating by means of Thermal Gravimetric Analysis (TGA). Also Infrared detectors, Thermal conductivity detectors etc. can be used to follow the desorption.
The analysis by Redhead is today quite outdated, it is hardly encountered today in the literature. There exist much more precise methods to derive kinetic and adsorption data from the desorption curves. A summary from ca. 1990 is given by De Jong and Niemantsverdriet( A.M. de Jong, J.W. Niemantsverdriet, Thermal desorption analysis: Comparative test of ten commonly applied procedures, Surf. Sci., 233, 355-365, (1990)) describing some advantages and disadvantages of several approaches.
The terms "Temperature Programmed Desorption" abbreviated as "TPD" or thermal desorption are often encountered for this technique. These are probably better terms, as the technique is not a spectroscopic technique, but a thermal analysis. — Preceding unsigned comment added by Ton Janssens (talk • contribs) 21:57, 6 January 2011 (UTC)