Detection of thiodiglycol vapours using tin dioxide-based gas sensors: study of the interaction mechanism

This paper deals with the detection of an organosulphur compound, the thiod iglycol (TDG), using tin dioxide-based cas sensors. This compound is therma lly unstable. The fact that tin dioxide-based gas sensors have working temp eratures that can reach 600 degreesC could be the cause of misinterpretatio ns concerning the response obtained during the detection of TDG vapours. Th e results presented in the first part of this paper concern the study of th e thermal degradation of TDG vapours with, in particular, the precise ident ification and quantification of light degraded compounds by gas chromatogra phy. Next, the results are linked to the interpretation of the gas sensor's electrical response during the detection of TDG. In order to understand th is response, each degraded compound must be analysed in order to obtain its contribution to the overall electrical response. (C) 2001 Elsevier Science B.V. All rights reserved.