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Determination of Zirconium, Hafnium, Niobium, Tantalum, Molybdenum and Tungsten in Aqueous Solutions by Radioisotopic Excited X-Ray Fluorescence

Published online by Cambridge University Press:  06 March 2019

Frank L. Chan
Affiliation:
Aerospace Research Laboratories Wright-Patterson Air Force Base, Ohio 45433
W. Barclay Jones
Affiliation:
Yale University, New Haven, Connecticut 06511
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Abstract

Previous investigations on the quantitative determination of sulfur, chlorine, potassium, calcium, scandium and titanium in aqueous solutions by a radioisotopic excited fluorescent spectrometer has been extended to include other elements which are very difficult to separate and determine quantitatively by chemical methods. Six elements taken for the investigation and some of the results to be presented in this paper are:

  • (1) zirconium,

  • (2) hafnium,

  • (3) niobium,

  • (4) tantalum,

  • (5) molybdenum and

  • (6) tungsten.

As in previous investigations, aqueous solutions have been used because of the ease in obtaining exact concentrations and homogeneous mixtures of the elements under investigation.

In the earlier investigations which have been reported in this conference, lighter elements (atomic numbers ranging from 16 to 22) were used for the investigation. In the present studies, however, comparatively heavier elements have been used. Therefore a radioisotope such as iron 55 used earlier is not suitable because it cannot excite the K x-ray of these elements. To excite the K and L of these elements, we use the radioisotope iodine 125. The advantage of using this radioisotope is that it is inexpensive and commercially available although its half-life is comparatively short.

The spectrometer used with further improvements has been described and presented earlier. We used a multi-channel analyzer of 1000 in the present investigation, A liquid cell was specially designed for thisr study. Chemicals used for preparation of solutions were of reagent grades. Some of them had to be specially prepared. For example, hafnium, often contaminated with zirconium, was specially prepared and checked spectroscopically. Some difficulties have been encountered in preparing concentrated solutions such as niobium and tantalum due to the inherit characteristics of these elements to form insoluble compounds. Procedures will be described for the preparation of these solutions. Instruments used and results will be presented in this paper.

Type
Research Article
Copyright
Copyright © International Centre for Diffraction Data 1971

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References

1. Chan, Frank L., “Precipitation and Determination of Tantalum and Niobium from Homogeneous Solution with 3:3': 4':5:7-Pentahydroxy flavanone,” Talanta, Vol. 7, pp. 253263 (1961).Google Scholar
2. Moshier, Ross W., “Analytical Chemistry of Niobium and Tantalum,” Pergamon Press, London (1964).Google Scholar
3. Chan, Frank L. and Moshier, Ross W., “Spectrophotometric Determination of Molybdenum in Steel with 3:3':4':5:7- Pentahydroxyflavanone,Talanta, Vol. 3, pp. 272276 (1960).Google Scholar
4. Birks, L. S. and Brooks, E. J., “Hafnium-Zirconium and Tantalum and Columbian: System,” Anal. Chem. Vol. 22, p.1071 (1950).Google Scholar
5. Campbell, William J., “Energy Dispersion X-ray Analysis Using Radioactive Sources,” X-ray and Electron Methods of Analysis, H. van Olphen and W. Parish eds., Plenum Press, New York, pp. 3654 (1968).Google Scholar
6. Carr-Brion, K. G. and Payne, K. W., “X-ray Fluorescence Analysis,” The Analyst, Vol. 95, No.1137, p.997 (1971).Google Scholar
7. Jones, W. Barclay and Carpenter, Robert A., “Sensitivity of a Nondispersive X-ray Fluorescent Spectrometer for Multielement Trace Analysis.” Paper presented at the Second International Symposium on Nucleonics in Aerospace held in Columbus, Ohio, 12-14 July 1967.Google Scholar
8. Jones, W. Barclay and Carpenter, Robert A., “Nondispersive X-ray Fluorescent Spectrometer,” in Newkirk, John B., Mallett, Gavin R. and Pfeiffer, Heinz G., Editors, Advances in X-ray Analysis, Vol. 11, Plenum Press, New York, pp. 214229 (1968).Google Scholar
9. Chan, Frank L., “Dispersive and Nondispersive X-ray Fluorescence Methods for the Measurement of the Thickness of Films of Cadmium Sulfide and Other II-VI Compounds,” in Grove, E. L. and Perkins, Alfred J., Editors, Developments in Applied Spectroscopy, Vol. 7A, Plenum Press, New York, pp 330 (1969).Google Scholar
10. Chan, Frank L. and Jones, W. Barclay, “Quantitative Determination of Sulfur, Chlorine, Potassium, Calcium, Scandium and Titanium in Aqueous Solutions by Radioisotopic Excited Fluorescent Spectrometer and by Conventional X-ray Spectrometer,” in Newkirk, J. B. and Ruud, C. O., Editors, Advances in X-ray Analysis. Vol. 14, pp. 102126, Plenum Press, New York (1971).Google Scholar