A micromachined gas chromatographic column to optimize the gas selectivity for a resistive thin film gas sensor

Abstract

Indoor air quality monitoring applications require both high selectivity and sensitivity, which are difficult to reach with solid state gas sensors. An ultra small packed gas chromatographic column designed for a micro total analyzing system (μTAS) based on a solid state gas sensor as a detector and used to determine the concentration of benzene, toluene and xylene (BTX) in indoor and outdoor environments is described. The gas chromatographic approach allows a further selectivity enhancement (Terry et al., 1979), especially towards volatile organic compounds, which are hardly detected by solid state gas sensors at concentrations typically found in indoor and outdoor air. This work deals with the realization and the characterization of microfabricated ultra small packed silicon gas chromatographic columns (GCC) loaded with different stationary phases. In this paper the first results of the characterization of the first loaded GCC and the comparison with the results of the loaded capillary column are presented.