Assessment of conducting polymer odour sensors for agricultural malodour measurements

The major odoriferous components of fresh pig slurry were identified using gas chromatography coupled to mass spectrometry. From the analytical data, a standard artificial slurry was reconstituted. The performance of conducting polymer odour sensor arrays was evaluated using the individual chemical volatile components and the artificial slurry itself. Most of the components are discriminated from each other, when presented singly to the sensor array. The sensors are not poisoned by the chemicals and give reproducible responses over a 3 month period. The odour components being detected from an artificial alkaline pig slurry appear to be associated with patterns obtained from indole, skatole and ammonia. The intensity of the signal is proportional to the concentration of the volatiles presented to the sensor. The results indicate that conducting polymer sensor arrays show promise for measurement of agricultural malodours, and may complement olfactometric techniques.