Stability study of carbon graphite covered quartz crystal

This paper shows the properties and the possibilities of carbon graphite-covered quartz crystal as an organic gas-sensing device. The carbon graphite formed on a side of quartz plate was supported by Pt electrodes. The prepared quartz crystals were heat treated for the enhancement of stability in the temperature range from 100 to 450 degrees C. Impedance analysis of the carbon graphite-covered quartz crystal showed a larger admittance value than that of a Lipid coated quartz crystal, which was based on our previous method for detecting gas components. Using the adsorption and desorption responses, the reproducibility and sensitivity are presented for describing the merits of carbon graphite-covered quartz crystal in the detection of organic gas components. The comparison of sensitivity between commercially available alcohol sensor and carbon graphite-covered quartz crystal is provided for a ppm of ethanol injection. These results prove that the carbon graphite-covered quartz crystals are usable as an organic gas sensor and as an analytical device. (C) 1999 Elsevier Science S.A. All rights reserved.