Gaseous contaminants in SF/sub 6/ interacting with alumina

The interaction between CO/sub 2/ or SOF/sub 2/ (10/sup 3/ to 10/sup 4/ ppm/sub v/) and alumina (10 g) in SF/sub 6/ was investigated. The adsorption kinetics was monitored by taking online gas samples. A gas chromatograph coupled to a thermal-conductivity detector served to assess the concentration of each species in the mixtures. Under the chosen experimental conditions, no matrix effect was detected, since the sorptive kinetics involving CO/sub 2//SF/sub 6/ proved similar to that observed with CO/sub 2//He. The adsorption of SOF/sub 2/ was found to be stronger than that observed for CO/sub 2/, although part was transformed into SO/sub 2/. When the alumina sample was exposed to CO/sub 2/ then to SOF/sub 2/, some of the CO/sub 2/ adsorbed was released, demonstrating a preferential adsorption on alumina.