Abstract
The sensing capabilities of plasma organic films for gas plumes of volatile organic compounds (VOCs) have been examined by the newly developed measuring system using the VOC-impregnated beads. The humidity and flow rate of the system could be kept constant by means of the temperature-constant bath. Response curves to the VOC plumes are characterized by the maximum and minimum frequency shifts of quartz crystal resonator coated with plasma organic film. Using both parameters, the principal component analysis has shown that the score plot was discriminative between normal hydrocarbons, alcohols, and ketones. Each components in the same functional groups are enough separated by carbon chain length, using the humid air as the carrier gas. The negative shifts of response curves should play an important role in the discrimination of VOCs. This characteristic negative shifts are thought to be induced by desorption of the water adsorbates, which should contain the amphiphilic VOC, in the vicinity of the film surface.
