A number of analytical methods make use of the X-ray region of the electromagnetic spectrum. Of these, the technique in widest use is energy-dispersive X-ray fluorescence (EDXRF). EDXRF instruments begin by irradiating the sample with X-rays, which ionize atoms in the sample. Because of the high energy of X-rays, even tightly bound inner-shell electrons can be liberated, leaving empty quantum electron states at the lowest energy levels. This situation is inherently unstable, and electrons in outer shells make transitions to fill the vacated states. This transition results in the emission of photons, which carry away the difference in the energy levels of the two states. The energies of the photons in this fluorescence are characteristic for each element. Detectors measure the energy spectrum of the emitted photons and peaks can be analyzed to determine the elemental composition of the sample. EDXRF can measure elemental compositions ranging from percent to trace quantities, giving the technique broad applicability.
Energy dispersive X-ray fluorescence market demand by product type — 2010.
There are three major subtypes of EDXRF instruments. Standard laboratory models include familiar benchtop and floor-standing spectrometers for bulk analysis of samples. Over the past decade, a vibrant market for handheld EDXRF has developed, with miniaturized X-ray sources and detectors allowing the analysis to be carried out in the field, albeit with some diminution of capability. A third interesting product type is the microspot EDXRF instrument, in which the X-ray optics focus the illumination into a small spot, roughly 10–100 µm in diameter, so that individual locations on a sample can be analyzed. Combined, global sales of EDXRF instrumentation amounted to $564 million in 2010.
The foregoing data were adapted and extracted from SDi's market analysis and perspectives report entitled Global Assessment Report, 11th Edition, October 2010. For more information, contact Michael Tice, VP of Consulting Services, Strategic Directions International, Inc., 6242 Westchester Parkway Suite 100, Los Angeles, CA 90045, (310) 641-4982, fax: (310) 641-8851,