Application of a quartz microbalance based gas sensor array for the study of halitosis

Research into the monitoring and control of oral malodor has nowadays received new stimulus from the importance gained by this phenomenon as a medical and social problem. In this paper the performance of an electronic nose to detect this manifestation has been investigated in order to explore the possibility of using this instrument as a complement to those already existing for the assessment of oral malodor. In particular, a breath sampling procedure has been optimized to maximize the transfer to the sensors of those molecules that are known to be associated with the malodor. The sensitivity of electronic nose sensors to hydrogen sulfide, butyric acid and valeric acid-three compounds known to play a major role in halitosis-has been measured and the results indicate that the threshold limits are compatible with halitosis detection. An experiment with real and artificial samples indicates the possibility of identifying halitosis-affected individuals and of discriminating them according to breath composition.