Solid sampling electrothermal atomic absorption spectrometry for analysis of aluminium oxide powders

Abstract

An atomic absorption spectrometer with a transversely heated graphite tube and a solid sampling system based on the boat technique was used for the direct determination of Co, Cr, Cu, Fe, K, Mg, Mn, Ni and Zn in high-purity aluminium oxide powders. The high background absorption caused by gaseous aluminium and aluminium suboxides could be eliminated by optimization of the atomization temperature and integration time, and by pyrolytic recoating of the graphite tube. Sample amounts of up to 6 mg per atomization were applied. Calibration was performed by using aqueous solutions. Limits of detection between 0.25 ng g^–1 (Mg) and 25 ng g^–1 (Co) were achieved. The accuracy was checked by comparison of the results with those obtained by instrumental and radiochemical neutron activation analysis and by other independent methods.