XRF Basics

A routine solution for chemical analysis of metals and minerals, X-ray fluorescence (XRF) analysis offers both qualitative and quantitative insights into the elemental composition of samples (from traces to % levels) based on their unique XRF spectra. These spectra can be read in the field for instant elemental analysis using handheld XRF analyzers. Handheld XRF is a tried-and-tested tool for applications requiring immediate feedback such as scrap metals analysis. More robust quality assurance and control (QA/QC) requires laboratory-based XRF analysis, which breaks down into two primary types: EDXRF and WDXRF.

A convenient front-end analysis tool, EDXRF (energy-dispersive XRF) enables quick and easy analysis of even irregular samples with little-to-no sample preparation. WDXRF (wavelength-dispersive XRF), meanwhile, is the standard test method for a wide range of applications due to its outstanding sensitivity and high resolution.

If you would like to learn which method of XRF analysis is suitable for your field, speak with a member of our experienced team.

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What is XRF?

X-ray fluorescence (XRF) analysis is a technique that exploits the unique interaction between primary X-rays and matter. All matter is made of atoms and at the centre of every atom is a nucleus, which is positively charged due to the presence of protons (+ve charge) and neutrons (no charge). Electrons (-ve charge) orbit the nucleus in discrete quanta known as shells. Their total negative charge balances out the positive charge of the nucleus, rendering the atom neutral. This can be altered by introducing external energy, such as X-rays. X-rays are subvisible waves of light with very short wavelengths, thus very high energy, which are absorbed while passing through substances – depending on the composition and density of the substance.

When an atom is struck by an X-ray with enough energy (exceeding the atom’s shell binding energy), an electron within its innermost orbital shells is ejected, creating a vacancy. An electron from a higher atomic orbit will drop down to the vacancy in this lower energy state. This requires an emission of energy in the form of fluorescence, or secondary X-rays, which equals the specific difference in energy between the electron’s two quantum states.

Secondary X-rays are characteristic to individual elements in the periodic table. When a sample is analysed via XRF, every element present will emit these unique X-ray signals in the form of a spectrum. This spectrum, also known as an elemental fingerprint, is central to the performance of both EDXRF and WDXRF.

Obtaining a legible XRF spectrum can be complicated by a number of limitations (Rayleigh or Compton scattering, spectral effects, matrix effects, etc.). To ensure accuracy of results, it is often critical to perform empirical calibration or Fundamental Parameters (FP) analysis.

In EDXRF analysis, the characteristic X-rays of different elements present in a reading are separated into a complete fluorescence energy spectrum using either direct excitation (2D optics) or indirect excitation (3D optics). You can learn more about each of these excitation geometries by downloading our guide posters using the forms below. EDXRF technology is engineered to simultaneously process whole groups of elements for qualitative or quantitative analysis and can be used in portable and laboratory-based formats. As a result, EDXRF can accommodate samples of almost any shape and size.

WDXRF is preferred to EDXRF for high resolution applications (~15-150 eV) and analysis of lower atomic mass elements and rare earths. Rather than process a complete spectrum, WDXRF separates fluorescent signals into individual wavelengths using crystals and a series of optical components (collimator, optical encoders, detectors, etc.).

Both EDXRF and WDXRF are robust solutions in their own right, performing key functions in markets as varied as metals and alloys manufacturing, petrochemicals, forensics, food analysis, environmental analysis, and much more.

Understanding the elemental composition of your materials at multiple touchpoints in the workflow process can help you adapt to new challenges unique to your market sector. We offer the products, services and technologies to help you understand your materials, regardless of the application. See our listing of resources for XRF in these areas:

XRF Product Guide

Achieve qualitative and quantitative analysis for process and quality control. Laboratory-based XRF systems can evaluate all kinds of materials and sample types.

Energy dispersive (EDXRF) and wavelength dispersive X-ray fluorescence (WDXRF) are among the most powerful tools in the analytical chemist’s toolkit, making the distinct elemental fingerprints of samples available for analysis at the push of a button. We leverage both methods to accommodate the widest possible range of customer requirements with flexible lab-based and portable XRF solutions. These technologies are now pivotal to a world of applications including earth exploration, food research, manufacturing, scrap metals, and more.

We offer an extensive range of benchtop and portable floor-standing XRF solutions that operate in stand-alone modes or combined with additional elemental and structural analysis technologies.

View here our X-ray complete portfolio of products -  Brochure: XRF Product Range.

Download our comprehensive  eBook: XRF Technology in the Lab.

ARL PERFORM'X Sequential X-Ray Fluorescence Spectrometer

Solve analytical challenges in a wide range of applications with X-ray fluorescence with sample surface mapping and small spot analysis.

  • Analyze Be to Am in solids, fused beads, powders or liquids
  • Wide dynamic range from sub ppm to 100%
  • Choice of generator power
  • Small spot capability down to 0.5 mm
  • Advanced sample mapping feature
ARL OPTIM'X WDXRF Spectrometer

Meet a wide range of elemental analysis challenges in the petroleum, cement and slags industries using wavelength dispersive x-ray fluorescence spectrometry.

  • Analyze O to Am in solids, fused beads, powders or liquids
  • Best sensitivity for F to Fe enables precise analysis of cement, slag, ceramics, feldspar, glass, ores and minerals
  • Ideal for routine applications in process control and general laboratories
  • Low power consumption, integrated vacuum pump, minimal site requirements
ARL QUANT'X EDXRF Spectrometer

Accomplish the most challenging analytical tasks in research and manufacturing with powerful x-ray fluorescence technology for nondestructive elemental analysis of any sample.

  • Analyze F to Am in samples of any shape, type or composition
  • A cost-effective all-round and stand-alone XRF solution
  • Popular with laboratories for research, forensics, environmental analysis, regulatory compliance and quality control
  • Large sample chamber for multi-point sample analysis
  • Sample imaging and adjustable beam size
ARL 9900 Simultaneous-Sequential XRF Series

Save money and achieve quality control in your industrial process with full simultaneous and sequential capabilities integrated into one instrument.

  • Analyze Be to Am in solids, fused beads or pressed powders
  • Unbeatable speed, precision and light-element sensitivity
  • Configurable for your applications with choice of goniometers, monochromators and XRD system
  • Choice of generator power depending on the analysis speed required
  • Safe and reliable loading of samples with X-ray tube above the sample

Featured XRF videos

ARL QUANT’X EDXRF Spectrometer: ­Provides major, minor and trace element quantification across the broadest range of samples for central and contract laboratories

ARL OPTIM’X WDXRF Spectrometer:­ Compact WDXRF with sequential/simultaneous analysis capabilities for qualitative and quantitative characterization of all types of unknown samples

ARL PERFORM’X Sequential XRF Spectrometer:­ Solve analytical challenges in a wide range of applications with X-ray fluorescence for sample surface mapping and small spot analysis

ARL 9900 Simultaneous WDXRF and Integrated XRD System for complete elemental and structural analysis

Advanced ARL PERFORM’X WDXRF Spectrometer: Application at FLUXANA

ARL PERFORM’X WDXRF Spectrometer: 3D animation of the inside of the spectrometer

XRF Posters - Quick Guide and WD/EDXRF Periodic Tables
XRF downloads - quick guide and periodic poster

We offer you our X-ray Fluorescence Spectrometry Quick Guide poster summarizing the XRF basic theory, technology and main applications, as well as Periodic Table posters for Energy-Dispersive and Wavelength-Dispersive XRF. Download them now for free!

Download the posters