STUDIES ON EXCITATION PARAMETERS.
Summary technical rept. no. 1, 1 Nov 64-31 Oct 65,
UNITED STATES INDUSTRIAL CHEMICALS CO CINCINNATI OHIO
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The work described is concerned with the effect that excitation parameters have on the sensitivity and reproducibility of emission spectrochemical techniques for the analysis of trace elements in niobium and molybdenum. The parameters chosen include current, atmosphere composition, pressure, vacuum, electrode shape, and electrode material. A mixture of silver chloride and silver fluoride in a 11 ratio was found to be the most effective carrier for a niobium matrix and a combination of silver chloride, silver fluoride, copper oxide, and graphite was for a molybdenum matrix. Impurities in niobium oxide are evolved in 90 seconds by a carrier distillation method. Temperature studies indicate that a pyrolytic graphite barrier does increase the temperature of the electrode cup, but the improvement in carrier distillation is not apparent. The atmosphere chamber was used for moving plate studies at reduced pressures in an argon atmosphere. For niobium oxide, as the pressure is reduced the elements are more efficiently distilled from the electrode cup.
- Inorganic Chemistry