A NEW CHEMILUMINESCENCE-BASED SENSOR FOR DISCRIMINATING AND DETERMINING CONSTITUENTS IN MIXED GASES

Chemiluminescence (CL) is observed during the catalytic oxidation of various combustible vapours on a la!rer of aluminium oxide (gamma-Al2O3) powder in air. A new chemiluminescence-based sensor has been prepared applying this phenomenon. The working mechanism of the sensor is based on the production of chemiluminescent species, e.g., formaldehyde and carbor, as intermediate species of catalytic oxidation of the vapours. Three methods of detection by the sensor are demonstrated: (i) continuous determination and discrimination of a vapour by CL spectrum measurements; (ii) determination and discrimination of a vapour by CL glow-cure measurements; and (iii) separate determination of constituents in mixed vapours. Ethanol, butanol, acetone, n-butyric acid and xylene are determined by the sensor. The lower detection limit of the vapours is the order of 1 ppm or less, except for xylene.