Classification and evaluation of sensing films for QCM odor sensors by steady-state sensor response measurement

When we discriminate gases using quartz crystal microbalances (QCMs) odor s ensors, it is important to understand gas sorption characteristics of sensi ng film materials coated on their electrodes and to select them according t o target gases. Although we have so far studied the properties of various k inds of sensing film materials by a flow-type odor sensing system to measur e transient responses, the steady-state responses are measured in the prese nt study to evaluate partition coefficient precisely. Twenty-four sensing f ilm materials were chosen from gas chromatography (GC) stationary phases an d lipids, 41 sample gases from volatile organic compounds (VOCs) and odoran ts as sample gases. Then, we tried to classify the sensing films using prin cipal component analysis (PCA). As the result of analysis, it was found tha t sorption characteristics of GC materials mainly depend on their polarity. The properties of lipid films do not depend on the number of carbon atoms (C16, 18, 20) in the tails but depend on the kind of head group and the num ber of double bond in the tail. Moreover, we tried to classify the odorants using those 24 kinds of sensors and PCA. (C) 2000 Elsevier Science S.A. Al l rights reserved.