Elemental X-ray fluorescence analysis of various materials
- Chemical analysis of mineral raw materials, products of enrichment and processing of ores, as well as impurities in water
- Chemical analysis of oil and oil products for the content of sulfur, phosphorus, chlorine and chlorides, as well as heavy metals
- Elemental chemical analysis of oils and additives
- Determination of the composition of catalysts and catalyst sludge
- Eetermination of the composition of corrosion products
- Carrying out art criticism examinations
- Determination of the composition of alloys, etc.
The first description of X-ray fluorescence analysis (XRF) as spectroscopic analysis method was published by Glocker and Schreiber in 1928. The first XRF instrument was constructed by Friedman and Burks in 1948. XRF analysis is a highly accurate, fast and non-destructive method with low detection limits (0.1 - 10 ppm) and high reproducibility of results. The advantages of XRF include simple and fast sample preparation, as well as the fact that the sample can be analyzed almost any number of times.
The method is based on the registration and subsequent analysis of the energy spectrum obtained using a spectrometer from a sample irradiated with external X-rays. When exposed to external X-ray radiation, the atom goes into an excited state, accompanied by the transition of electrons to higher quantum levels. An atom stays in an excited state for an extremely short time, nearly within one microsecond, then it returns to the ground state (relaxes). In this case, the electrons returning to the ground state emit energy - a photon. Since the distances between levels for an atom of each chemical element are strictly defined, the photons emitted by electrons during the transition from one level to another will have a strictly defined energy. One can say with certainty which chemical element they belong to by measuring the energy of emitted photons on a spectrometer.
The materials to be analyzed can be solids such as glass, ceramics, metal, rock, coal, plastics, or liquids such as gasoline, oils, paints, solutions, blood, and even wine. XRF allows to determine the concentration of chemical elements from beryllium to uranium in solid, liquid and powder samples of various origins. Both X-ray tubes and radionuclide sources based on iron-55 (55Fe), cadmium-109 (109Cd), cobalt-57 (57Co) etc. can be used as a radiation source.