Detection of hydrogen sulphide using cataluminescence sensors based on alkaline-earth metal salts

Abstract

Detection of hydrogen sulphide (H(2)S) was conducted based on cataluminescence (CTL) sensors, using alkaline-earth metal carbonates as catalysts. Optimal working conditions, analytical characteristics and the response properties of the sensor were investigated. CTL intensity examination showed that sensors fabricated with CaCO(3), SrCO(3) or BaCO(3) could be used to detect H(2)S gas sensitively. The optimal sensing temperature was about 320 °C. Under the sensing conditions with temperature at ca. 320 °C and gas flow rate in the range 180-200 mL/min, the linear range of CTL intensity vs H(2)S concentration was 25-500 ppm, with a detection limit of 2 ppm. The response and recovery times of the sensor were within 5 and 25 min, respectively. Also, the sensor had the property of high selectivity to H(2)S with very weak or no obvious response to 14 other gases, such as NO(2), NH(3), hydrocarbons and alcohol.