Separation of Effects due to Superimposition Using the Rietveld Method in Spectra Obtained by WDXRF


Article Preview

This paper presents a new method to separate interfering spectra obtained in wavelength dispersive x-ray fluorescence spectrometry (WDXRF). This method permits improved results to be obtained, compared to conventional analytical results and enables the determination of chemical species of the same element without chemical separation. This is done by separation of the spectra due to electronic transitions of the valence electrons. The Rietveld method [11] overcomes the problem of superimposed peaks of the species present in the specimen and simultaneously enables determination of the species and does not require standard specimens and calibration curves. This signifies a marked improvement in comparison to other techniques. Specimen surface preparation to obtain spectra is a critical stage and its effects can be minimized by using Rietveld refinement, which permits the determination of intensity relationships of superimposed peaks with the aid of mathematical models. This establishes the basic conditions to obtain more accurate results in quantitative analysis. In the determination of chemical species, it is possible to separate, for example, Cr (III) and Cr (IV), with almost 100% superimposition.



Materials Science Forum (Volumes 530-531)

Edited by:

Lucio Salgado and Francisco Ambrozio Filho




V.L.R. Salvador and N. B. de Lima, "Separation of Effects due to Superimposition Using the Rietveld Method in Spectra Obtained by WDXRF", Materials Science Forum, Vols. 530-531, pp. 59-64, 2006

Online since:

November 2006





[1] ASADA, E.; TAKIGUCHI, T.; SUZUKI, Y. The Effect of Oxidation State on the Intensities of Kβ5 and Kβ" of 3d-Transition Elements. X-Ray Spectrometry, v. 4, pp.186-189, (1975).

DOI: 10.1002/xrs.1300040408

[2] FERREIRA, M.M.C.; ANTUNES, A.M.; MELGO, M. S; VOLPE, P.L.O.; Aplicação de Alguns Modelos Quimiométricos à Espectroscopia de Fluorescência de Raios-X de Energia Dispersiva. Quim. Nova 1999, 22, 724.

DOI: 10.1590/s0100-40422002000600012

[3] IWATSUKI, M.; FURASAWA, T. Kβ2/ Kβ1, 3 X Ray Intensity Ratios of As, Se and Br in Various Chemical States. X-Ray Spectrometry, 16: 73-79, (1987).

DOI: 10.1002/xrs.1300160207

[4] JENKINS, R.; GOULD, R.W.; GEDCKE, D. QUANTITATIVE X-RAY SPECTROMETRY. New York, Marcel Dekker, Inc., (1981).

[5] KLOCKENKÄMPER, R.; KOCH, K.H. Determination of Various Phases of Al in Steel by X-Ray Fluorescence Spectrometry. X-Ray Spectrometry, 18: 177-181, (1989).

DOI: 10.1002/xrs.1300180409


[7] LARSON, A.C. and VON DREELE, R.B. General Structure Analysis System (GSAS). Los Alamos National Laboratory Report LAUR 86-748 (2004).

[8] MAZZILLI, B. Chemical effects in X-ray emission spectra of tranition metal compound,. Tese de Doutoramento, (1982).

[9] NAGATA, N e Bueno, M.I.M.S. Métodos Matemáticos para Correção de Interferências Espectrais e Efeitos Interelementos na Análise Quantitativa por Fluorescência de RaiosX. Quim. Nova, Vol. 24, No. 4, 531-539, (2001).

DOI: 10.1590/s0100-40422001000400015

[10] PINKERTON, A.; NORRISH, K.; RANDALL, P.J. Determination of Sulfhur in Plant Material by X-Ray Fluorescence Spectrometry. X-Ray Spectrometry, vol. 19, pp.63-65, (1990).

DOI: 10.1002/xrs.1300190207

[11] RIETVELD,H.M.; A Profile Refinement Method for Nuclear and MagneticStructures. J. Appl. Cryst. 2, pp.65-71, (1969).

[12] TANNINEN, V.P.; MIKKOLA, E.; HYVÄRINEN, K.H.; GREKULA, A., KALLIOMÁKI, P.L. Determination of the Valence of the Iron in Welding Fumes with the Kβ Emission Spectrum. X-Ray Spectrometry, vol. 14, n. 4, (1985).

DOI: 10.1002/xrs.1300140410

[13] TOBY B.H., EXPGUI, a graphical user interface for GSAS, J. Appl. Cryst. 34, 210-213 (2001).

DOI: 10.1107/s0021889801002242

[14] URCH, D.S.; WOOD, P.R. The Determination of the Valency of Manganese in Minerals by X-Ray Fluorescence Spectroscopy. X-Ray Spectrometry, vol. 7, n. 1, (1978).

DOI: 10.1002/xrs.1300070105

[15] VAN GRIEKEN, R.E.; MARKOWICZ, A.A. Handbook of X-ray Spectrometry: Methods and Techniques. Marcel Decker, USA, (1993).

[16] YOUNG, R.A.; Using Rietveld Method; School of Physics, Georgia Institute of Technology; Atlanta, (1994).

[17] YOUNG, R.A. The Rietveld Method. I.U. C, Oxford University Press Inc., New York; (1995).

Fetching data from Crossref.
This may take some time to load.