Detection of dimethyl methylphosphonate (DMMP) by tin dioxide-based gas sensor: Response curve and understanding of the reactional mechanism

This paper deals with the detection of dimethyl methylphosphonate (DMMP), using tin dioxide-based gas sensors. One of the characteristics of this device is the functioning temperature, which ranges between 25 and 500 °C. The results presented in the first part of this paper concern the study of the thermal degradation of DMMP vapours, in particular the identification and quantification of light and heavy degraded compounds by several analysis techniques (IR, NMR, GC).The second part of this paper is dedicated to the interpretation of the gas sensor's responses during the detection of DMMP and the determination of the origin of the electrical response of the sensor.Finally in the third part of this paper, we propose a reactional mechanism which describes the interactions between DMMP vapours and SnO2 surface, that occurs during the detection of this phosporous compound.