Hostname: page-component-5c6d5d7d68-thh2z Total loading time: 0 Render date: 2024-08-07T00:44:01.075Z Has data issue: false hasContentIssue false
  • English
  • Français

Trace Element Analysis using Total-Reflection X-Ray Fluorescence Spectrometry

Published online by Cambridge University Press:  06 March 2019

Andreas Prange  and
Heinrich Schwenke
Andreas Prange
Affiliation:
GKSS Research Centre, Institute for Physics, P.O. Box 1160 D-2054 Geesthacht, Germany
Heinrich Schwenke
Affiliation:
GKSS Research Centre, Institute for Physics, P.O. Box 1160 D-2054 Geesthacht, Germany
Get access

Abstract

For the application of TXRF in trace element analysis, two characteristic features of the total reflection of X-rays are exploited. These are the high reflectivity on flat surfaces and the low penetration depth of the primary radiation. This allows the application of TXRF for both chemical trace and ultra-trace element analysis on the one hand and surface analysis on the other. For chemical trace clement analysis, total reflection on a highly polished substrate is characterized by a high reflectivity, which leads to a drastic reduction of the spectral background. The sample to be analyzed is prepared on the substrate as a residue of small quantities by evaporation from solutions or fine-grained suspensions. Instrumental detection limits of a few pg or sub-ng/ ml−1 arc state of the art for commercially available equipment. Besides the high detection power, internal standardization is another important feature of TXRF, enabling very simple quantification of the detected elements. The small sample mass required enables especially ultra-micro analytical questions to be tackled. For trace element analysis in surfaces the low penetration depth of the primary radiation under the conditions of total reflection is exploited. The penetration depth is in the range of a few nanometers, hence, TXRF is intrinsically surface sensitive. Detection limits better than 1010 atoms/cm2 are obtained for metal impurities on silicon wafers. For the examination of layered structures elemental composition, layer thickness, and density can be derived from die angle-dependent fluorescence intensities. The present paper describes the basic features of the total reflection of X-rays and gives some representative examples of the different uses of TXRF in trace element analysis.

Type
XII. Total Reflection XRS
Information
Advances in X-Ray Analysis , Volume 35 , Issue B: First Pacific-International Congress on X-ray Analytical Methods (PICXAM). Fortieth Annual Conference on Applications of X-ray Analysis, August 7-16, 1991 , 1991 , pp. 899 - 923
Copyright
Copyright © International Centre for Diffraction Data 1991

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

1. Yoneda, Y. and Horiuchi, T., Optical Flats for Use in X-ray Spectrochemical Microanalysis, Rev. Sci, Instr. 42: 1069(1971)Google Scholar
2. Aiginger, H. and Wobrauschek, P., A Method for Quantitative X-ray Fluorescence Analysis in the Nanogram Region. Nucl. Instr. Methods 114: 157 (1974)Google Scholar
3. Knoth, J. and Schwenke, H., An X-ray Flourescence Spectrometer with Totally Reflecting Sample Support for Trace Analysis at the ppb Level, Fresenius Z. Anal. Chem. 291:200(1978)Google Scholar
4. Schwenke, H. and Knoth, J., A Highly Sensitive Energy-Dispersive X-Ray Spectrometer with Multiple Total Reflection of the Exciting Beam, Nucl. Instr. Methods 193: 239 (1982)Google Scholar
5. Freitag, K., Energy Dispersive X-Ray Fluorescence Analysis with Multiple Total Reflection - An Improvement of Detection Limits, in: B. Sansoni (Ed.) Instrumentelle Multielementanalyse, VCH Verlagsgesellschaft, Weinheim (1985) pp. 257–268 Google Scholar
6. Eichinger, P., Rath, H.J. and Schwenke, H., Application of total reflection X-ray fluorescence analysis for metallic trace impurities on silicon wafer surfaces, ASTM Spec. Tech. Publ. 990: 305 (1989)Google Scholar
7. Underwood, J. H., Glancing Incidence Optics in Astronomy, Space Sci. Instr. 1: 289 (1975)Google Scholar
8. Streii, C., Wobrauschek, P. and Aiginger, H., Light Element Analysis witfi TXRF, this volumeGoogle Scholar
9. Prange, A., Total reflection X-ray spectrometry: method and applications, Spectrochim. Acta 44B:437 (1989)Google Scholar
10. Prange, A., Knochel, A. and Michaelis, W., Multi-Element Determination of Dissolved Heavy Metal Traces in Sea Water by Total-Reflection X-Ray Fluorescence Spectrometry, Aca. Acta 172:79(1985)Google Scholar
11. Stößel, R.-P. and Prange A., Determination of Trace Elements in Rainwater by Total- Reflection X-Ray Fluorescence, Aca. Acta 57: 2880 (1985)Google Scholar
12. Prange, A., Knoth, J., Stößel, R.-P., Boddeker, H. and Kramer, K., Determination of Trace Elements in the Water Cycle by Total-Reflection X-Ray Fluorescence Spectrometry, Anal.Chim.Acta 195: 275 (1987)Google Scholar
13. von Bohlen, A., Klockenkjimper, R., Otto, H., Tölg, G. and Wiecken, B., Qualitative survey analysis of thin layers of tissue samples - Heavy metal traces in human lung tissue, Int.Arch.Occup.Environ.Health 59: 403 (1987)Google Scholar
14. KlockenkSmper, R., von Bohlen, A. and Wiecken, B., Quantification in total reflection X-ray fluorescence analysis of microtome sections, Spectrochim, Acta 44B: 511 (1989)Google Scholar
15. Prange, A., Kramer, K. and Reus, U., Determination of trace element impurities in ultrapure reagents by total reflection X-ray spectrometry, Spectrochim. Acta 46B: in press (1991)Google Scholar
16. Iida, A., Sakurai, K., Yoshinaga, A. and Gohshi, Y., Grazing Incidence X-ray Fluorescence Analysis, Nucl. Instr. Methods A246: 736 (1986)Google Scholar
17. Weisbrod, U., Gutschke, R., Knoth, J. and Schwenke, H., Total Reflection X-ray Fluorescence Spectrometry for Quantitative Surface and Layer Analysis, Appl. Phys. A53: 2031 (1991)Google Scholar
18. Weisbrod, U., Gutschke, R., Knoth, J. and Schwenke, H., X-ray induced fluorescence spectrometry at grazing incidence for quantitative surface and layer analysis, Fresenius Z. Anal. Chem. 341: 83 (1991)Google Scholar
19. de Boer, D.K.G. and Leenaers, A., XRF and TXRF of (Multiple) Thin Films, X-Rav .Spectrometry, in press (1991)Google Scholar