The first choice for use in an increasing range of applications, such as medicine, mineralogy, agriculture, manufacturing, construction, geology, and archeology, X-ray fluorescence (XRF) spectrometry and analysis has undergone significant advancement over the past century. XRF spectrometry is a nondestructive, non-intrusive analytical technique that can be used to determine the chemical composition of metals, glass, ceramics, and other materials in various physical states such as solids, powders, coatings, and liquids. Many samples can be analyzed with little to no preparation, making XRF an easy quality check compared to other analysis techniques. Cost and size minimizations are among the most important advancements expanding the use of XRF instruments worldwide. Two decades ago the first handheld XRF (HHXRF) technology became commercially available, enabling a vital transition from stationary benchtop XRF instrumentation to mobile devices enabling spectrometry and analysis in the field.
However, despite the numerous advancements, the heart of all XRF technology—the generation of X-rays—has been stagnant since 1895. At the end of the 19th century, Wilhelm Conrad Roentgen was studying cathode rays emitted from a high-voltage gaseous discharge tube. He happened to notice that a barium-platinocyanide screen encased in a cardboard box that was lying near the experiment would fluoresce whenever the tube was in operation, despite being surrounded by opaque material. Thus, X-rays were discovered! Then, in 1909, Charles Glover Barkla discovered a connection between X-rays radiating from a sample and the atomic weight of the sample, establishing the foundations of XRF technology. However, nearly 40 years passed before the first XRF spectrometer was built by Herbert Friedman and Laverne Stanfield Birks, Jr., paving the way for commercial use of XRF technology. Figure 1 depicts the spectrometry and analysis process for XRF, a nondestructive measurement.