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Energy Dispersive, X-Ray Fluorescence Analysis

X-Ray Spectrometry

  1. Peter Wobrauschek1,
  2. Christina Streli1,
  3. Eva Selin Lindgren2

Published Online: 15 JUN 2010

DOI: 10.1002/9780470027318.a6806.pub2

Encyclopedia of Analytical Chemistry

Encyclopedia of Analytical Chemistry

How to Cite

Wobrauschek, P., Streli, C. and Selin Lindgren, E. 2010. Energy Dispersive, X-Ray Fluorescence Analysis. Encyclopedia of Analytical Chemistry. .

Author Information

  1. 1

    Vienna University of Technology, Atominstitut, Vienna, Austria

  2. 2

    University of Borås, Rector's Office, Borås, Sweden

Publication History

  1. Published Online: 15 JUN 2010

Abstract

Energy-dispersive X-ray fluorescence (EDXRF) is an analytical method for qualitative as well as quantitative determination of elements in a sample, independent of their chemical form. It is built on the fact that elements that are irradiated with high-energetic X-rays have a certain probability of emitting characteristic X-rays, the energies of which are unique for each element. In the energy-dispersive (ED) systems, the emitted X-rays are detected via their energies. The use of the EDXRF technique has accelerated since the 1960s as a result of the development of liquid nitrogen cooled solid-state detectors, nuclear electronics, and small computers. Nowadays compact light-weight electrically cooled detectors are available, which, together with air-cooled low-power X-ray tubes, are perfectly suited for handheld spectrometers. EDXRF is multielemental and nondestructive and can be applied to large as well as small samples of different composition and character. If conditions are optimized, minimum detection limits can be below the nanogram absolute or micrograms per gram concentration level for small laboratory instruments and into the femtogram or nanograms per milliliter region for more advanced instrumentation (total reflection X-ray fluorescence (TXRF), synchrotron radiation).

EDXRF spectrometers exist at many degrees of sophistication, ranging from advanced laboratory instruments to small portable instruments for field observations. They can be designed for analysis of bulk material or for scanning and elemental mapping of small areas. The use of X-ray optics like single or polycapillaries and curved mirrors in Kirkpatrick–Baez geometry lead to X-ray spot sizes of micrometers and below ideally suited for micro-XRF. Mapping with high spatial resolution is thus possible opening investigations down to cell dimension.

Typical applications for EDXRF are analysis of agricultural material, medical samples, archaeological and historical objects, painting and fine art objects, and environmental samples such as soil, ores, water, and aerosol particles.

Keywords:

  • XRF;
  • EDXRF;
  • micro-XRF;
  • TXRF;
  • synchrotron radiation XRF;
  • X-ray optics;
  • X-ray detectors;
  • quantitative XRF;
  • chemical speciation