XRF

What is it?

XRF is an analytical (simultaneous multi-element) method for determining the chemical composition of all kinds of materials. The materials can be in solid, liquid, powder (pressed pallets or fused beads), filtered or other form. This technique can also be used to determine the thickness and composition of layers and coatings.
The method is fast, accurate and non-destructive and usually requires only a minimum of sample preparation. Many samples can be examined with little or no pre-treatment.

What is it used for?

Applications are very broad and include (in many fields of science, research and quality control) the metal, cement, oil, polymer and food industries, along with mining, mineralogy and geology, environmental analysis of water and waste materials and pharmacy.
The precision and reproducibility of XRF analysis is very high. Very accurate results are possible when good standard specimens are available but also in applications where no specific standards can be found. The elements that can be analysed range from fluoride to uranium and the concentration range goes from sub-ppm (reliable trace element analysis) levels to 100%. Elements with high atomic numbers have better detection limits than lighter elements.

Equipment and working conditions

The system used is a Panalytical AXIOS-Advanced WDXRF (wavelength dispersive) spectrometer fitted with an SST-MAX X-ray source (rhodium target) with a 4kW output and can be operated at 160mA. The AXIOS uses SuperQ software for standard-based analysis and has a standard-less software module called OMNIAN capable of giving the complete composition and quantification of most types of unknown materials. For sample preparation, the laboratory has a variety of sample preparation tools including presses, milling, furnace and fused beam machines.

Example of use

Some examples of analysis are:

• Analysis of major and minor elements in metal alloys (e.g. cast iron, steel, titanium alloys, aluminum, copper and nickel)
• Analysis of major and minor components of slag, soils and cement samples
• Analysis of toxic heavy elements (Cr, Ni, Cu, Zn, As, Br, Cd, Ba, Hg and Pb), or additives in polymers.Analysis of major elements and selected trace elements in geological materials prepared as fused beads
• The analysis of wear metals and additives in lubricating oils
• Analysis of elemental impurities (heavy metals) in pharmaceutical materials
• Determination of low sulfur content in petroleum products and automotive fuels and analysis of P, S, Ca and Zn in lubricating oils