Carrier-distillation method for spectrographic analysis and its application to the analysis of uranium-base materials

Abstract

A method of fractional distillation in the direct-current arc was developed for the spectrographic determination of 33 volatile impurity elements at concentrations as low as a fraction of a part per million in uranium-base materials. The method involves (1) the conversion of the sample matrix to a form having low volatility, (2) the addition of a small amount of a selected volatile "carrier" material, and (3) partial distillation of the mixture in a direct-current arc with an electrode assembly of improved design. In the analysis of uranium-base materials, the sample was converted to the oxide U30S and gallium oxide was added as a carrier (2 parts Ga203, 98 parts UaOs). The procedure was applied to the determination of Ag, AI, As, Au, B, Ba, Be, Bi, Cd, Co, Cr, Cs, Cu, Fe, Ge, H g, In, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, Sb, Si, Sn, TI, V, and Zn. Repeated results for B, Cd, Si, Fe, Mg, and Mn, determined photometrically, agreed within ± 10 percent. The high sensitivity and general applicability of the method are results of the characteristic that the refractory sample matrix is not volatilized appreciably, during the period that the minute quantities of impurity vapors are swept into the arc by the carrier.

Anion Exchange Characteristics of the Elements in Nitric Acid and Nitrate Solutions and Application in Trace Element Analysis

“…(34j Analysis for silicon and boron w^as made w^ith a separate sample portion by the carrier distillation method. (103) Neptunium A procedure similar to that described for thorium w^as applied to the analysis for neptunium. Samples of from 25 to 100 mg were reduced to Np(lV) by heating for at least an hour in an 8M nitric acid, 0.2M hydrazine solution.…”

The Spectra of the Heavy Elements

“…In most cases, the spectra were made available because of the necessity of conducting spectrochemical analyses on a number of samples for impurities. * Because of limitations of sample size, it was not feasible to perform the analyses with the aid of chemical or physical 1 separations, and so the spectrum of the major constituent was always present. It would be of considerable interest to provide descriptions of the spectra which would be adequate for term analyses leading to energy levels and electron configurations, not only for the spectroscopic interest but also for the assistance they might provide in the correlation of chemical properties of these elements.…”

Curium Process Development. Iii-7. Emission Spectrographic Determination of Metallic Impurities in Curium Oxide and Mixed Curium--Americium Oxide

“…For this reason, some separation technique must be used before or during the emission spectrographic determination of trace quantities of metallic impurities in curium oxide and mixed curium-americium oxide. Solvent extraction, 6 • 7 ion exchange," and carrier distillation 9 techniques have been used for separating various actinides from metallic impurities. Solvent extraction and ion exchange techniques are time-consuming and not sufficiently general in application.…”