Abstract

Spectrographic methods applicable to the determination of major rare earth constituents in complex mixtures are described. The specific examples discussed are the determination of yttrium and gadolinium in the concentration range of 10 to 100 percent. The procedures involve the high current d.c. arc excitation of rare earth oxide sample-ceric oxide-graphite mixtures. Selected lines of cerium are used as internal standards. The choice of cerium as internal standard was based on the relative ease with which any cerium, if present in a mixture, could be preferentially separated from the mixture and then reintroduced in a standard amount. Precision studies show a standard deviation of about ±2.5 percent for single determinations. The results from a quantitative study of (a) vaporization rates, (b) intensity diagrams of the internal standard line pairs along the longitudinal axis of the arc discharge, and (c) the effect of large changes in excitation conditions on the intensity ratios show that this high precision can be attributed to a high degree of internal standard compensation of excitation variables.

© 1949 Optical Society of America

The Quantitative Spectrographic Analysis of the Rare Earth Elements*I. Determination of Samarium in NeodymiumII. Determination of Europium in Samarium

Velmer A. Fassel and Harley A. Wilhelm
J. Opt. Soc. Am. 38(6) 518-526 (1948)

Quantitative Spectrographic Analysis of Zirconium-Hafnium Mixtures*

Velmer A. Fassel and Charles H. Anderson
J. Opt. Soc. Am. 40(11) 742-747 (1950)

Characteristics of Pulsed Arcs in Spectrochemical Analysis. Part I: Zinc Alloys

D. A. Sinclair
J. Opt. Soc. Am. 39(11) 958-966 (1949)

The Influence of Extraneous Elements on Line Intensity. IV. Extraneous Element Effects in the Direct-Current Arc*

Wallace R. Brode and Donald L. Timma
J. Opt. Soc. Am. 39(6) 478-481 (1949)

Spark Spectra of Elements 43 and 61*

D. L. Timma
J. Opt. Soc. Am. 39(11) 898-902 (1949)