Determination of Selenium and Tellurium in the Gas Phase using Specific Columns and Atomic Absorption Spectrometry

Total selenium and tellurium in the gas phase were analyzed after adsorption on gold-coated beads and charcoal. The thermally eluting gas was trapped on columns filled with quartz beads that were cooled in an ice bath. The beads were boiled in dilute HCl, and the resulting solution was analyzed for Se and Te by graphite furnace atomic absorption spectrometry. Our results demonstrate that gold-coated beads efficiently trap gaseous Se and Te at a low gas flow rate, but at higher flow rates charcoal traps are more expedient. With charcoal traps, it was found that local air samples contain Se in the range of 0.92-3.05 ng m-3 and Te in the range of 0.10-0.34 ng m-3. Detection limits down to about 0.1 ng m-3 allow the ready detection of Se and Te in rural air with a precision of about ±6% at the nanogram level of Te and about ±4% at the nanogram level of Se