HYDRIDE GENERATION AAS PERFORMED AT 1800-2300-DEGREES-C ATOMIZATION TEMPERATURE USING A GRAPHITE-FURNACE

Mutual interferences of As, Bi, Sb, Se, Sn and Te in the determination of As, Sb, Se and Sn by hydride generation AAS performed at atomization temperatures between 1800 and 2300°C were investigated. The sensitivities for As, Sb and Se were similar to that obtained with a conventional quartz tube, whereas Sn showed a completely different behaviour. Radiotracer experiments indicated that tin was strongly adsorbed on the graphite inlet tube. In processing a typical amount of ca. 50 ng of the element to be determined, the addition of 10-100 μg of any of the interfering elements, under the optimized conditions, does not cause a signal depression greater than 12%. In this way, the acceptable concentration range of the interfering elements can be increased by up to three orders of magnitude as compared with the conventional quartz tube technique. However, problems to be solved include reactions of water and hydrogen with heated graphite which give rise to an increased background. © 1990 Springer-Verlag.