- XRF is a versatile, non-destructive and quick technique used for elemental and compositional analysis of both powder and liquid samples.
- It is used in the steel and construction industry for quantitative analysis.
- In the plastics industry it is used to determine wearing, identify traces of worn off metal traces from metal inserts
- It is also used in geological and ecological samples to run a quick analysis of the major and trace elements
- It is used by archaeologists for compositional analysis of ancient excavations. It is used in forensic science to match samples in crime analysis.
In XRF, atoms excited by an external energy source emit x-ray photons of certain wavelength. The intensity (number of photons) emitted at each wavelength are counted and this indicates and quantifies the elements present in the sample. These characteristic radiations are emitted when x-rays force the electrons in the inner-shell of the atom to the outer shell and the outer shell electrons quickly move to fill the vacancies in the inner shell. X-rays have a relatively shorter wavelength compared to visible light in the range of 100 A to 0.1 A. Therefore, x-rays can pass through substances easily and it also gets stronger as the atomic number of the substance decreases. The fluorescent x-rays have energies characteristic to each element and help in qualitative analysis of the sample by Moseley’s law.