Solid sampling electrothermal atomic absorption spectrometry using the boat technique and a transversely heated grraphite tube was applied to dirrect analysis of graphite and silicon carbide powders for 14 and 12 impurity elements, respectively. With graphite, for all analytes under investigation, a very effective in situ analyte/matrix separation was achieved. That was the case also for analytes in silicon carbide requiring atomization temperatures below 2400 ºC. At higher atomization temperatures, the decomposition products of silicon carbide give rise to significant background, which can still be corrected.
Sample amounts of up to 4 mg graphite and 8 mg silicon carbide per analysis cycle were applied. For all analytes in both materials, limits of detection at the lower ng/g and sub-ng/g level were achieved, excluding arsenic for which they were 50 ng/g and 23 ng/g fr gaphite and silicon carbide respectively. Quantification was performed using calibration curves mesured with aqueous standard solutions. The accuracy was checked by comparision of the results with those obtained by instrumental neutron activation analysis and by other independent methods.
This is the abstract of an article published by Uwe Schäffer and Viliam Krivan, from Faculty of Natural Sciences, Universität Ulm, Germany.
We have carried out determinations of metal impurities in silicon carbide, in collaboration with the research gupo called MARTE, and from the department of analytical chemistry at the University of Zaragoza (Spain), obtaining excellent results.
The device used for this is contrAA 700 with automatic solid sampler for graphite furnace. Each measurement time is 4 minutes approximately.
You can analyze solids directly in any of our models with graphite furnace, reducing costs and time of analysis.
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