Micro X-ray fluorescence, sometimes stylised as µXRF but more often referred to as micro XRF, is a powerful analytical tool with a wide range of practical applications. It is an extremely versatile spectroscopic method ideal for elemental composition analysis and highly visual elemental surface mapping. But how does micro XRF actually work?
In this post, we will outline the working principles of Micro XRF and its benefits, as well as the differences between standard and micro XRF.
What is Micro XRF?
Micro XRF is a colour map of a material’s surface that provides elemental identification. It is a non-destructive form of spectroscopy that provides rapid screening of trace-level elements for an array of sample types. With outstanding precision, high resolution, and fast scanning capabilities, micro XRF is a truly cost-effective analytical solution. The cost-benefits of high throughput are compounded by the fact that micro XRF spectrometers are compatible with many sample types with no preparation required. Micro XRF is subsequently highly versatile, with routine applications in archaeology, bioscience, forensics, geological studies, materials science and more.
Micro-XRF is widely used in materials science, geology, and industrial research for non-destructive elemental analysis.
How Does Micro XRF Work?
Conventional XRF spectroscopy uses high-energy X-rays to excite atoms in a bulk sample and induce fluorescence. Briefly: X-ray fluorescence occurs when electrons closely orbiting nuclei become excited and transition to a higher energy orbital, before relaxing back to their ground state. This relaxation requires a loss of energy, hence the emission of X-ray fluorescence. XRF spectroscopy, including micro XRF, acquires the unique spectral emissions—or fingerprint—of samples to determine their composition. Micro XRF depends on those same basic principles.
Described as an energy-dispersive form of X-ray spectroscopy, micro XRF uses polycapillary and doubly curved X-ray optics to create minute focal points on the surface of the sample. Focusing the X-ray beam into a micrometre-sized spot allows users to accurately map surface elements while simultaneously obtaining compositional information. These features make micro XRF the perfect method for small feature evaluation, measuring film and plating thickness, forensics and many other applications.
The actual working method varies depending on the type of micro XRF spectrometer used. Some are mobile and reconfigurable, meaning that they can be brought into the field for in situ analysis of different samples. Simply aim the spectrometer at your sample for rapid, non-contact measurements. Benchtop devices typically have a sample chamber where samples must be placed, but the same limited sample prep benefits apply to non-portable devices.
Benefits of Micro XRF?
There are multiple benefits to micro XRF; however, one of the main advantages is that it is a non-invasive, non-destructive method of analysing a wide range of samples. Additional benefits of micro XRF are as follows:
- No sample preparation required for any sample types (liquids, powders and liquids)
- Sample material does not need to be cut, ground or dissolved
- Fast measurements: 0.3ms per pixel
- High spatial resolution: down to <20 µm X-ray spot size
- Irregular shapes can be analysed easily
- No sample damage
- Versatile and can be used in a range of industries
- Analyse elements as light as Oxygeb
These benefits are utilised in applications such as art (paints and pigments), geology, biomaterials, metals, forensic science, corrosive products, pathology, pharmaceuticals, archaeology and many more industries where contamination may occur, and materials need to undergo sample testing.
For laboratories requiring advanced elemental analysis, high-performance XRF systems such as the Bruker S6 JAGUAR and S8 TIGER are commonly used, supported by dedicated instrument service and support to ensure reliable long-term operation. For laboratories in Denmark looking to apply micro-XRF techniques, BlueScientific provides local expertise and support for research and industrial applications.
As an authorised distributor of Bruker Micro-XRF systems, BlueScientific supports laboratories across the UK and Europe with expert advice, local application support and ongoing service. If you would like to discuss micro XRF solutions or request a quote, please contact our team at info@blue-scientific.com to discuss your requirements.