Ethanol interference in light alkane sensing by metal-oxide solid solutions

A study of the sensing properties of chemoresistive metal-oxides vs. light alkanes has been undertaken under wet condition and in presence of ethanol. Screen-printed films of a solid solution of mixed Sn and Ti oxides have been selected for the purpose. We demonstrated that the films are capable of detecting 100 ppm of light alkanes or 500 ppm of methane in wet condition, two concentration levels by far lower than their alarm thresholds, respectively. Ethanol is known to be a harmful interfering gas, though its concentration can be reduced to values lower than 10 ppm by proper filtering. We show that, even in presence of 10 ppm of ethanol, the films steadily responded to alkanes.