Thermodesorption Mass Spectrometry TDMS

Fundamentals. Besides introduction of gaseous species into the ionization chamber, other techniques have been employed to transfer species to be analysed [861]. For analysis of materials adsorbed or deposited as solids on an inert support, thermally induced desorption is a possible approach. The flow of particles desorbing from the surface, which is heated with the temperature increasing linearly with time, is analysed with respect to intensity and particle mass. Results yield information about the strength of bonding and/or adsorptive interaction and about the chemical composition of the species. An alternative approach is the use of secondary ion mass spectrometry (SIMS) [862, 863]. Obviously both approaches are feasible only under 

UHV conditions. As has been demonstrated in selected cases, the electrochemical double layer may adhere to an electrode surface upon emersion of the electrode from an aqueous electrolyte solution [864] making this method a valid approach. 

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