Analysis of silicon carbide powder by ETV-ICP-AES

Summary A direct tandem atomic spectroscopic method for the determination of Ca, Fe and Ti impurities in SiC powders with various grain size (0.7850<48.5 m) has been developed. The method is based on high temperature halogenation of the sample with Freon 12 in a graphite furnace and ICP-AES detection of the evolved sample components. The concentration of the matrix element silicon in the ICP increased to a maximum value after 10s of heating, independent of the grain size of the powder samples. For performing a calibration with standard solutions a finegrained, purified SiC-powder was evaporated simultaneously with the solution residues. The calibration curves produced using this analyte-addition technique and using within-laboratory solid standards were identical within experimental error.Presented at the 5th International Colloquium on Solid Sampling with Atomic Spectroscopy, May 18–20, 1992; Geel, Belgium. Papers edited by R. F. M. Herber, Amsterdam