What is XRF?
X-Ray Fluorescence (XRF):
A non-destructive analytical technique used to determine the chemical composition of materials.
XRF occurs when a fluorescent (or secondary) x-ray is emitted from a sample that is being excited by a primary x-ray source. Because this fluorescence is unique to the elemental composition of the sample, XRF is an excellent technology for qualitative and quantitative analysis of the material composition. XRF spectrometry has a broad range of applications in industry.
X-rays:
X-rays are simply light waves that we can't see. Other light waves that we can't see include ultraviolet (UV) light (which gives you a sun tan), infrared light (which warms you up), and radio waves. X-rays have a very short wavelength, which corresponds to a very high energy.
Properties of X-Rays
X-rays Are:
Propagated in straight lines at speed of light.
Absorbed while passing through matter, depending on composition and density of the substance.
Emitted with energies characteristic of the elements present.
They:
Affect the electrical properties of liquids and solids.
Cause biological reactions such as cell damage or genetic mutation.
Darken photographic plates.
Ionize gases.
How XRF Works？
Fingerprints
Each of the elements present in a sample produces a unique set of characteristic x-rays that is a “fingerprint” for that specific element.
What is an Element?
An element is a chemically pure substance composed of atoms. Elements are the fundamental materials of which all matter is composed. The elements are arranged in increasing order of their atomic weight (the number of protons in the nucleus of an atom).
How are characteristic X-rays produced?
X-rays are used to bombard the sample, which is excited to produce X-ray fluorescence.
X-rays usually knock the inner electrons out of the K and L layers of an elemental atom, creating holes that are filled by high-energy outer electrons. The high-energy electrons that replenish the low-energy orbitals radiate the excess energy as X-ray fluorescence.
These radiated spectral lines contain features of various elements. Like fingerprints and are independent of the chemical valence states of the atoms. The intensity of the radiation is proportional to the concentration of that element in the sample.
