Hostname: page-component-76fb5796d-25wd4 Total loading time: 0 Render date: 2024-04-29T09:13:47.265Z Has data issue: false hasContentIssue false

Rare-earth element determination in minerals by electron-probe microanalysis: application of spectrum synthesis

Published online by Cambridge University Press:  05 July 2018

S. J. B. Reed
Affiliation:
Dept. of Earth Sciences, University of Cambridge, Downing St., Cambridge CB2 3EQ, UK
A. Buckley
Affiliation:
Dept. of Earth Sciences, University of Cambridge, Downing St., Cambridge CB2 3EQ, UK

Abstract

Electron-probe microanalysis (EPMA) is applicable to rare-earth elements (REE) in minerals with relatively high REE concentrations (e.g. hundreds of parts per million). However, given that each of the 14 REE has at least 12 X-ray lines in the L spectrum, finding peak-free regions for background measurement can be problematical. Also, measured peak intensities are liable to require correction for interferences. Hitherto, little attention has been paid to the optimisation of background offsets and the implications of the wide variation in REE distribution patterns in different minerals. The ‘Virtual WDS’ program, which enables complex multi-element spectra to be synthesised, has been used to refine the conditions used for different REE distributions. Choices include whether to use the Lβ1 rather than the Lα1 line, background offsets, and counting times for comparable relative precision. Correction factors for interferences affecting peak and background measurements have also been derived.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Åmli, R. and Griffin, W.L. (1975) Microprobe analysis of REE minerals using empirical correction factors. Amer. Mineral., 60, 599606.Google Scholar
Donovan, J.J., Snyder, D.A. and Rivers, M.L. (1993) An improved interference correction for trace element analysis. Microbeam Anal., 2, 23–8.Google Scholar
Exley, R.A. (1980) Microprobe studies of REE-rich accessory minerals: Implications for Skye granite petrogenesis and REE mobility in hydrothermal systems. Earth Planet. Sci. Lett., 48, 97110.CrossRefGoogle Scholar
Lábár, J.L. and Salter, C.J. (1991) Uncertainties in the analysis of M X-ray lines of the rare-earth elements. In Electron Probe Quantitation, (Heinrich, K.F.J. and Newbury, D.E., eds.). Plenum Press, New York, pp. 223–49.CrossRefGoogle Scholar
Reed, S.J.B. and Buckley, A. (1996) Virtual WDS. Mikrochim. Acta (Suppl.), 13, 479–83.Google Scholar
Roeder, P.L. (1985) Electron-microprobe analysis of minerals for rare-earth elements: use of calculated peak-overlap corrections. Canad. Mineral., 23, 263–71.Google Scholar
Solberg, T.N. (1988) Electron microprobe trace element analysis. In Microbeam Analysis - 1988, (Newbury, D.E., ed.). San Francisco Press, pp. 485–90.Google Scholar
Williams, C.T. (1996) Analysis of rare earth minerals. In Rare Earth Minerals: Chemistry, Origin and Ore Deposits, (Jones, A.P. et al., eds.). Mineral. Soc. ser. 7, Chapman and Hall, London, pp. 327–48.Google Scholar