Читать книгу X-Ray Fluorescence in Biological Sciences - Группа авторов - Страница 14

XRF spectrometry is generally used in two different kinds of configurations: wavelength dispersive mode (WD‐XRF) and energy dispersive mode (EDXRF) [8, 9]. Both of them have different ways of detecting and analyzing emitted fluorescent X‐ray photons. ED‐XRF spectrometers have detection systems which examine the distinct energies of the X‐ray photons coming directly from the sample material. The XRF spectrum is generated by detecting and plotting the relative count numberings of X‐rays at each energy value. The energy dispersive detectors basically involve the creation of electron–hole pairs in semiconductor materials (Si). After the emergence of silicon drift detectors (SDD), EDXRF is mainly used. As compared with EDXRF, WDXRF is quite expensive and is not needed for testing materials for steel industry or ceramics industry, for which EDXRF is enough. In recent years, EDXRF leads over WDXRF and is a powerful tool for elemental analysis to determine major, minor, and trace elements in biological samples [3]. EDXRF spectrometers are simpler in design, smaller, and more cost effective than other technologies. Examples of some common EDXRF applications include: quantifying atomic elements in: food, animal feed, cosmetics, woods, toothpaste, cement, kaolin clay, granular catalysts, ores, and many others.

One more difference between the techniques is that with an EDXRF system, the full spectrum is obtained virtually at once. So, a range of elements belonging to the periodic table can be determined simultaneously. With an WDXRF system, the spectrum has been procured by a series of discrete step, which is time‐consuming, and also expensive due to the restricted number of detectors.