Graphite-tube effects on perchloric acid interferences on aluminum and thallium in the stabilized-temperature platform furnace

Abstract The determination of aluminum in the presence of perchloric acid is shown to depend upon the quality of the pyrolytic coating of furnace tubes. With new pyrolytically coated tubes, no interference was found from 0.5 M HClO 4 on 0.5 ng Al and no decrease in signal or deterioration of the pyrolytic coating was found after more than 150 firings. Very little interference was found in the determination of thallium in perchloric acid. In both cases the literature reported severe interferences. The determination of thallium and aluminum in perchloric acid appears to be more sensitive to the quality of the pyrolytic graphite coating than any of the materials studied previously here.