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 thiodiglycol (TDG), using tin dioxide-based gas sensors. This compound is thermally unstable. The fact that tin dioxide-based gas sensors have working temperatures that can reach 600°C could be the cause of misinterpretations concerning the response obtained during the detection of TDG vapours. The results presented in the first part of this paper concern the study of the thermal degradation of TDG vapours with, in particular, the precise identification and quantification of light degraded compounds by gas chromatography. Next, the results are linked to the interpretation of the gas sensor’s electrical response during the detection of TDG. In order to understand this response, each degraded compound must be analysed in order to obtain its contribution to the overall electrical response.