Methods for improving the sensitivity in flame atomic absorption spectrometry

Abstract

Various designs of water cooled silica tube atom traps are described and evaluated for analytical performance in flame atomic absorption spectrometry. The designs studied include single, double and triple tube atom traps. The double silica tube atom trap produced the best sensitivity, 3.1 and 0.46 ng ml^–1, for Pb and Cd, respectively. The detection limits were 0.8 and 0.1 ng ml^–1 for Pb and Cd, respectively, using a 2-min collection time. The sensitivity can be further improved by increasing the collection time. A procedure is outlined for the determination of Pb and Cd in water.