EDXRF explained or how to do the chemical analysis.


Energy Dispersive X-ray Fluorescence or EDXRF is known to scientist at least 50 years. It became very favorable tool to measure chemical compositions about 30 years ago. This is due to ability to produce by many companies a portable X-ray source and small Si-pin detectors.

Typical EDXRF spectrometer consists of:

  1. X-ray source. Very first X-ray sources were radioactive materials. In this days they are X-ray tubes. And with latest developments those X-ray tubes become so small that can fit on the tip of your finger.

  2. X-ray detector. This element can be constructed in so many different ways. The most common and least expensive is the Silicon drift detector. Normally such detector head is sitting behind an x-ray window in a vacuum. And this window is made from beryllium film.

  3. Small stage, where the sample sits on and  is shined by X-ray source,  secondary waves from that source received by X-ray detector.

  4. Electronics that works with X-ray detector signal. Normally signal has to be preamplified, buffered, resolved by energies and counted.

Very typical, broad range EDXRF covers all elements from sodium (Na) to uranium (U).

Modern EDXRF has very complex electronics that can resolve signal from X-ray detector and determine what kind of chemical element is in front of detector and what concentrations of such compound might be.

EXRF or XRF is very common tool for many analytical labs. Usage is very diverce: from applications in archaeology to metallurgy or forensics and many other areas, wher chemical analysys is needed. Recent developments in EDXRF is in miniaturization and hand-held devises.

We can predict that in the nearest future (10 years or so) we might see a device not bigger then a pack of cigaret.

There are companies that working very hard to develop miniature x-ray tubes and super-small x-ray detectors.

I remember 10 years ago, in 2005, I drove my Saturn Vue with small EDXRF spectrometer in the back. and that would be considered very revolutionary- to have transportable and powered from 12V DC EDXRF machine.

But today it is very old. Many companies made pistol-like EDXRF spectrometers, which looks like an average Bosh cordless drill.

 

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