Total-Reflection X-Ray Fluorescence Analysis and Related Methods

Reinhold Klockenkämper, Alex von Bohlen

• Publisher: Wiley
• Year: 2014
• ISBN:
  9781118988961
• Edition: 2
• Topic: Physical Sciences
• Subtopic: Analytic Chemistry

Explores the uses of TXRF in micro- and trace analysis, and in surface- and near-surface-layer analysis
•Pinpoints new applications of TRXF in different fields of biology, biomonitoring, material and life sciences, medicine, toxicology, forensics, art history, and archaeometry
•Updated and detailed sections on sample preparation taking into account nano- and picoliter techniques
•Offers helpful tips on performing analyses, including sample preparations, and spectra recording and interpretation
•Includes some 700 references for further study

Chapter 1
Fundamentals of X-Ray Fluorescence

1. 1.1 A Short History of XRF
2. 1.2 The New Variant TXRF
   1. 1.2.1 Retrospect on its Development
   2. 1.2.2 Relationship of XRF and TXRF
3. 1.3 Nature and Production of X-Rays
   1. 1.3.1 The Nature of X-Rays
   2. 1.3.2 X-Ray Tubes as X-Ray Sources
   3. 1.3.3 Polarization of X-Rays
   4. 1.3.4 Synchrotron Radiation as X-Ray Source
4. 1.4 Attenuation of X-Rays
   1. 1.4.1 Photoelectric Absorption
   2. 1.4.2 X-Ray Scatter
   3. 1.4.3 Total Attenuation
5. 1.5 Deflection of X-Rays
   1. 1.5.1 Reflection and Refraction
   2. 1.5.2 Diffraction and Bragg's Law
   3. 1.5.3 Total External Reflection
   4. 1.5.4 Refraction and Dispersion

X-ray fluorescence (XRF) is based on the irradiation of a sample by a primary X-ray beam. The individual atoms hereby excited emit secondary X-rays that can be detected and recorded in a spectrum. The spectral lines or peaks of such a spectrum are similar to a bar-code and are characteristic of the individual atoms, that is, of the respective elements in the sample. By reading a spectrum, the elemental composition of the sample becomes obvious.

Such an XRF analysis reaches near-surface layers of only about 100 μm thickness but generally is performed without any consumption of the sample. The method is fast and can be applied universally to a great variety of samples. Solids can be analyzed directly with no or only little sample preparation. Apart from the light elements, all elements with atomic numbers greater than 11 (possibly greater than 5) can be detected. The method is sensitive down to the microgram-per-gram level, and the results are precise and also accurate if matrix-effects can be corrected.

For these merits, XRF has become a well-known method of spectrochemical analysis. It plays an important role in the industrial production of materials, in prospecting mineral resources, and also in environmental monitoring. The number of spectrometers in use is estimated to be about 15 000 worldwide. Of these, 80% are working in the wavelength-dispersive mode with analyzing crystals; only 20% operate in the energy-dispersive mode, mainly with Si(Li) detectors, and recently with Si-drift detectors. At present, however, energy-dispersive spectrometers are four times more frequently built than wavelength-dispersive instruments due to the advantage the former provides in fast registration of the total spectrum.

A spectrum originally means a band of colors formed by a beam of light as seen in a rainbow. The Latin word “spectrum” means “image” or “app...

Table of contents

• Cover
• Series Page
• Title Page
• Copyright
• Foreword
• Acknowledgments
• List of Acronyms
• List of Physical Units and Subunits
• List of Symbols
• Chapter 1: Fundamentals of X-Ray Fluorescence
• Chapter 2: Principles of Total Reflection XRF
• Chapter 3: Instrumentation for TXRF and GI-XRF
• Chapter 4: Performance of TXRF and GI-XRF Analyses
• Chapter 5: Different Fields of Applications
• Chapter 6: Efficiency and Evaluation
• Chapter 7: Trends and Future Prospects
• Index
• End User License Agreement