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Analysis of silicates using wavelength‐dispersive x‐ray fluorescence spectrometry for major elements: effects of loss elimination and catch‐weights
Author(s) -
Hettipathirana T. D.,
Grey N. A.,
Naidu R.
Publication year - 2004
Publication title -
x‐ray spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.447
H-Index - 45
eISSN - 1097-4539
pISSN - 0049-8246
DOI - 10.1002/xrs.709
Subject(s) - analytical chemistry (journal) , matrix (chemical analysis) , x ray fluorescence , certified reference materials , chemistry , silicate , calibration , fluorescence , materials science , detection limit , chromatography , physics , optics , organic chemistry , quantum mechanics
Analysis of silicates using wavelength‐dispersive x‐ray fluorescence spectrometry was evaluated for the determination of the 10 most common major elements, Fe, Mn, Ti, P, Ca, K, Si, Al, Mg and Na and also Zr, Sr, S and Cl. The calibration was based on de Jongh alpha coefficients for loss‐eliminated matrix correction, a flux containing Li 2 B 4 O 7 and LiBO 2 and two‐level synthetic standards prepared in SiO 2 matrices (except for S and Cl). Sulphur and Cl standards were prepared in Al 2 O 3 matrices because of poor reproducibility of duplicates prepared in an SiO 2 matrix. Backgrounds for major elements (high peak‐to‐background ratio) were not measured. Trace elements (low peak‐to‐background ratio) were not determined and their matrix effects were not considered. The method was validated for the 10 most common major elements using 23 Certified Reference Materials covering a wide range of concentrations. The absolute error was <±0.2% for most determinations and within experimental error. Sulphur and Cl in high silicate concentrations were not accurately quantifiable owing to variable retention during the vigorous fusion of the SiO 2 matrix. For samples with high loss‐on‐fusion (LOF), catch‐weights caused a significant and systematic error for the major element with highest concentration. The presence of undetermined trace elements showed no significant effect except slightly overestimated LOF. For an accurate analysis, it is therefore necessary that nominal weights be used when LOF is high and all major elements are determined. The method is suitable for the ‘as received’ analysis of a wide variety of silicates for major elements. Copyright © 2004 John Wiley & Sons, Ltd.