X-ray fluorescence analysis (XRF) is an elemental composition analysis method based on the study of the characteristic fluorescence spectrum that occurs when a sample is irradiated with X-rays. Quanta of characteristic radiation is generated during the relaxation of an atom excited by X-rays into a more energetically favorable state. This is accompanied by the transition of one of the electrons of the atomic shell to the lower energy levels, and the emission of a quantum with an energy equal to the difference between the energies of the initial and final states.
The energies of the electronic levels are a function of the atomic number of the element, and therefore, based on the intensities of those present in the spectrum, one can draw conclusions not only about the presence of certain elements in the composition of the sample but also about their concentrations.
However, like any other method, XRF has its limitations. In particular, the method of X-ray fluorescence analysis is not suitable for determining the concentrations of elements with atomic number Z < 11, due to the strong scattering of low-energy X-rays in air.
How and Where XRF Analysis Is Used
Despite this, XRF is currently one of the most popular methods of elemental composition. XRF owes its popularity primarily to its simplicity, due to the fact that XRF spectrometers are extremely easy to use and do not require complex sample preparation before measurements, as well as speed, which allows you to quickly analyze a large number of samples.
X-ray fluorescence spectrometers are actively used in many areas of science and industry to solve a wide range of problems, in particular:
Analysis of Metals and Alloys
XRF analyzers are able to determine the grade of the alloy in seconds, which allows you to quickly analyze a large number of samples. Due to the fact that XRF is a non-destructive method, it is actively used in the quality control of both raw materials and finished products. However, as noted above, XRF is not applicable to the analysis of the concentrations of elements with atomic number Z < 11, which include carbon, which makes it inapplicable to the analysis of carbon steels.
Analysis of Precious Metals
X-ray fluorescence analysis makes it possible to determine with high accuracy the chemical composition of both gold ore and finished jewelry.
Analysis of Soils and Ores
The XRF method can be used to analyze both solid samples and loose samples, which makes it possible to use it in the analysis of ores during geological exploration, direct mining, or enrichment. In addition to laboratory XRF spectrometers, there is a wide range of portable handheld spectrometers on the market, which allows measurements to be taken in the field, thus reducing the time required for analysis from days to minutes compared to laboratory methods of analysis.
Analysis of Petroleum Products
XRF is used to determine the content of sulfur and metal impurities in oil, as well as to monitor the presence of wear metals in lubricating oils.
X-ray fluorescence analysis is used to study the content of heavy metals and toxic elements in waters or soils, as well as the analysis of atmospheric air pollution.
Analysis of Automotive Catalysts
XRF allows you to determine with high accuracy the concentration of platinum group metals in spent catalysts, which allows you to quickly and reliably estimate their cost.
Analysis of Cement
X-ray fluorescence spectrometers are used to analyze the chemical composition of raw materials, clinker, mineral additives, and finished cement, which allows us to ensure the quality of cement industry products and optimize the production process as much as possible.
Analysis of Refractory Materials
The chemical composition of refractory materials, in particular the percentage of refractory oxides, silicates, borides, and nitrides in their composition, determines their performance properties. XRF allows you to quickly assess the quality of the refractory material, and its suitability for certain tasks.
Analyzers According to the Rohs/WEEE Directive
The method of X-ray fluorescence analysis has a high sensitivity to heavy elements and is able to detect the presence of potentially harmful to human health heavy metals and other toxic substances at the level of 1 ppm.
In general, the XRF method is used to solve various tasks of determining the elemental composition of materials, but the possibilities of the method do not end there, and X-ray fluorescence analysis can also be used for such tasks as analyzing the thickness of metal coatings or determining the age and features of the manufacture of archaeological finds or works of art. . At present, Elvatech’s XRF guns is an actively developing method, and its possibilities, and, accordingly, the fields of application continue to expand.