Electrothermal atomic absorption spectrometry using an improved solid sampling system for the analysis of high purity tantalum powders

Abstract

A solid sampling atomic absorption method for the determination of Cu, Fe, Mn, Na and Zn in high-purity tantalum powders has been developed. It is based on a direct automatic introduction of the sample into the graphite tube using the platform technique. Standard hollow-cathode lamps in combination with deuterium background correction are used as radiation sources. This and some additional modifications of the Grün spectrometer hard- and software lead to a significant improvement of its performance. With the maximum applicable sample mass of 40 mg limits of detection of 1 ng g −1, 27 ng g −1, 1.5 ng g −1, 0.7 ng g −1 and 0.1 ng g −1, respectively, are achieved for Cu, Fe, Mn, Na and Zn. Aqueous standard solutions are used for calibration. Comparison of the results obtained by solid sampling atomic absorption spectrometry with those of the liquid sampling technique show satisfactory agreement.