In this paper, we propose a model of a sensor array system, which consists of three cataluminescence sensors based on nanosized SrCO3, gamma-Al2O3 and BaCO3 as catalysts, for quantitative analysis of the explosive gases of propane, n-butane and iso-butane in a mixture. Six linear regression equations of the cataluminescence intensity vs. the gas concentrations in the range 2000-10,000 ppm were established from the sensor array system at two working temperatures, as the explosive gases show different sensitivity to the three sensors. The least squares method was employed for solving the simultaneous equations and quantifying the concentrations of the three components. The detection limits (3sigma) of propane, n-butane and iso-butane on SrCO3, gamma-Al2O3 and BaCO3 sensors are 50, 40 and 20 ppm, 80, 60 and 40 ppm, and 20, 10 and 5 ppm, respectively. The concentrations of two artificial samples containing the tertiary mixture were analysed with satisfactory results.
Copyright 2005 John Wiley & Sons, Ltd.