Determination of silicon in titanium dioxide and zirconium dioxide by electrothermal atomic absorption spectrometry using the slurry sampling technique

Abstract

A method for the determination of silicon in titanium dioxide and zirconium dioxide powders based on electrothermal atomic absorption spectrometry using the slurry sampling technique has been developed. The experimental conditions with regard to chemical modification, the temperature programme, the lifetime of the graphite furnace and the slurry concentration were optimized. The behaviour of zirconium and calcium in the graphite tube during the ashing, atomization and cleaning steps was investigated using ⁴⁷Ca and ⁹⁷Zr as radiotracers. Calibration was performed by the standard additions method using aqueous standards. The results of this technique were compared with those for atomic emission spectrometry. The limits of detection were found to be 7 µg g^–1 in titanium dioxide and 2 µg g^–1 in zirconium dioxide, respectively.