Selective detection of (E)-hexenal in the sub-ppm range and of ethanol in the low-ppm-range using semiconducting gas sensors with temperature cycled operation

摘要

We use gas sensors with temperature cycled operation (TCO) for the detection of (E)-hexenal in thernconcentration range of 0.4 to 2.0 ppm and ethanol in the concentration range 2.4 to 12 ppm. We arernable to distinguish between these two reducing organic vapors in the ppm range and even to quantifyrn(E)-hexenal under any ethanol presence in this range. This was achieved by calculating linearrndiscriminant functions from the sensor reaction pattern to a stationary gas mixture flow. The obtainedrnLDA-coefficients, subsequently applied to the same feature set obtained at another time, can classifyrnthe gas mixture with respect to these components in the mentioned concentration range. Therntemperature profile during cycling operation was selected due to our prior experience with the usedrnsensor types.