Experimental methods in chemical engineering: X-ray fluorescence - XRF

X-ray fluorescence (XRF) is a non-destructive spectrometric technique to detect elements with an atomic number from 11 (sodium) and beyond 92 (uranium). When X-rays or gamma rays eject tightly bound inner core electrons, an electron from an outer shell will fill the empty orbital and fluoresce. Every element has a characteristic fluorescence, which depends on the element and the electrons in the orbitals that are ejected and those that fill the orbital. With the characteristic energy of the fluorescence, we determine elemental composition and concentration when adequately calibrated. Typical run times range from a second to a few minutes with an sensitivity to as low as 1 μg g⁻¹ (ppm). XRF guns are portable devices that produce qualitative data while libraries loaded to laboratory instruments are capable of producing quantitative data. A broad range of scientists and engineers apply XRF in research—140 of the 250 scientific categories in the Web of Science (WoS) cite XRF analyses. Of the 10,000 articles indexed in WoS since 2018, chemical engineering ranks fifth with the most articles. The focus of the research in this category includes adsorption and waste water, combustion and pyrolysis, catalysis and zeolites, and nanoparticles and oxidation.

Mots clés

elemental analysis; non-destructive; polymers; spectroscopy; WEEE; x-ray; xrf