Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-27T09:29:04.255Z Has data issue: false hasContentIssue false

Ion microprobe determination of rare earth elements in accessory minerals

Published online by Cambridge University Press:  05 July 2018

S. J. B. Reed*
Affiliation:
Department of Earth Sciences, University of Cambridge, Cambridge CB3 0EZ

Abstract

The application of ion microprobe analysis to REE determination is discussed, with special reference to REE-bearing accessory minerals (e.g. allanite, monazite, apatite, xenotime, sphene). The main analytical problems are shown to be (a) interferences in the mass spectrum caused by molecular ions, and (b) matrix effects, i.e. variations in ion yield with sample composition. Interference suppression using either high mass resolution or secondary-ion energy discrimination is fairly effective, but entails a significant sacrifice in peak intensity. In the absence of a viable model for predicting matrix effects, it is proposed that empirical standardization should be used. Often better absolute accuracy can be obtained by combining ion microprobe and electron microprobe data for REE present in sufficiently high concentrations. Detection limits for REE are in the part per million region at present, with spatial resolution typically around 10 μm, but there is considerable scope for improvement. Better standards and improved understanding of matrix effects should also lead to greater accuracy in quantitative analysis.

Type
Mineral Chemistry
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1986

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

Andersen, C.A., and Hinthorne, J.R. (1973) Anal. Chem. 45, 1421-38.Google Scholar
Banner, A.E., and Stimpson, B.P. (1974) Vacuum. 24, 511-17.Google Scholar
Brooks, C.K., Henderson, P., and Ronsbo, J.G. (1981) Mineral. Mag. 44, 157-60.Google Scholar
Colby, J.W. (1975) In Practical Scanning Electron Microscopy (J. I. Goldstein and H. Yakowitz, eds.), Plenum, New York, 529-72.Google Scholar
Compston, W., Williams, I.S., and Clement, S.W. (1982) In Proc. 30th Ann. Conf. on Mass Spectrometry and Allied Topics,Honolulu, Am. Soc. Mass Spectrom., 592-5.Google Scholar
Crozaz, G., and Zinner, E. (1985) Earth Planet. Sci Lett. 73, 41-52.Google Scholar
Degreve, F., Figaret, R., and Laty, P. (1979) Int. J. Mass Spectrom. Ion Phys. 29, 351-61.Google Scholar
Drake, M.J., and Weill, D.F. (1972) Chem. Geol. 10, 179-81.Google Scholar
Goodrich, C.A., Taylor, G.J., Keil, K., and Reed, S.J.B. (1985) In 16th Lunar and Planetary Sci. Conf. Abstr., 282-3.Google Scholar
Haskin, L.A., Haskin, M.A., Frey, F.A., and Wildeman, T.R. (1968) In Origin and Distribution of the Elements (L. H. Ahrens, ed.), Pergamon, New York, 869-912.Google Scholar
Henderson, P. (1984) Rare Earth Element Geochemistry. Elsevier, Amsterdam.Google Scholar
Ishizuka, T. (1974) Anal. Chem. 46, 1487-91.Google Scholar
Lindstrom, M.M., Crozaz, G., and Zinner, E. (1985) Lunar Planet. Sci. 16, 493-4.Google Scholar
Long, J.V.P., Astill, D.M., Coles, J.N., Reed, S.J. B., and Charnley, N.R. (1980) In X-ray Optics and Microanalysis (D. R. Beaman R.E.O.ilvie, and D. B. Wittry, eds.), Pendell Publ. Corp., Midland, Mich., 316-21.Google Scholar
Metson, J.B., Bancroft, G.M., Mclntyre, N.S., and Chauvin, W.J. (1983) Surf. Interf. Anal. 5, 181-5.Google Scholar
Reed, S.J. B. (1981) In Microbeam Analysis—1981 (R. H. Geiss, ed.), San Francisco Press, San Francisco, Calif., 8790.Google Scholar
Reed, S.J.B. (1983) Int. J. Mass Spectrom. Ion Processes. 54, 31-40.Google Scholar
Reed, S.J.B. (1984) Scanning Electron Microscopy 1984,529-35.Google Scholar
Reed, S.J.B. (1985) Chem. Geol. 48, 137-43.Google Scholar
Reed, S.J.B. and Smith, D.G.W. (1983) Nature. 306, 172-3.Google Scholar
Reed, S.J.B.and Smith, D.G.W. (1985) Earth Planet. Sci. Lett. 72, 238-44.Google Scholar
Sawka, W.N., Chappell, B.W., and Norrish, K. (1984) Geology. 12, 131-4.Google Scholar
Shimizu, N., Semet, M.P., and Allegre, C.J. (1978) Geochim. Cosmochim. Acta. 42, 1321-34.Google Scholar
Young, E.J., Myers, A.T., Munson, E.L., and Conklin, N.M. (1969) U.S. Geol. Surv. Prof, paper 650D, 8493.Google Scholar