DIRECT DETERMINATION OF IMPURITIES IN POWDERED SILICON-CARBIDE BY ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY USING THE SLURRY SAMPLING TECHNIQUE

A direct method of analysis of powdered silicon carbide for the determination of Al, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Ti, V and Zn based on electrothermal atomic absorption spectrometry (ETAAS) using the slurry sampling technique is described. Possible spectral interferences caused by the refractory matrix components were studied. The technique was optimized with regard to sample preparation, dispensing, thermal pre-treatment and atomization parameters. The accuracy was checked by comparison of the results with those obtained by ETAAS and inductively coupled plasma atomic emission spectrometry involving decomposition of the sample, and by instrumental neutron activation analysis. For most of the elements investigated the achievable limits of detection are at the sub-microgram per gram level.