Portable and Handheld Systems for Energy-Dispersive X-ray Fluorescence Analysis
Published Online: 15 MAR 2009
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Cesareo, R., Gigante, G. E., Castellano, A. and Ridolfi, S. 2009. Portable and Handheld Systems for Energy-Dispersive X-ray Fluorescence Analysis. Encyclopedia of Analytical Chemistry.
- Published Online: 15 MAR 2009
Energy-dispersive X-ray fluorescence (EDXRF) portable spectrometers are becoming very popular in many fields for the on-site analysis of elements. This is mainly because EDXRF is a nondestructive, multielemental technique that is extremely well suited for the analysis of any material.
An EDXRF spectrometer mainly consists of an X- or -ray excitation source, an X-ray detector with electronics, and a pulse-height analyzer. Recent technological developments have resulted in small, low-power, dedicated X-ray tubes, thermoelectrically cooled semiconductor detectors, and small pulse-height analyzers. Therefore, completely portable EDXRF spectrometers are available that can be assembled on-site, having the size of a book and a weight ranging from as light as 500 g (using a radioactive source) to a few kilograms (using an X-ray tube). These spectrometers can be employed for on-site analysis in various fields, such as works of art, alloys, soil, environmental samples, forensic medicine, paper, waste materials, mineral ores and their products, or anywhere a portable apparatus would be required.
This article reviews the present status of the development and application of EDXRF portable systems. The various components of a portable system are described: the radiation source, i.e. small, low-power, dedicated X-ray tubes or, alternatively, radioactive sources that emit X-rays or low-energy -rays; and X-ray detectors, i.e. proportional gas counters and semiconductor detectors, with special emphasis on the more recent thermoelectrically cooled X-ray detectors: Si-PIN (Positive-Intrinsic-Negative), Si-drift, CdTe, CdZnTe, HgI
Commercial systems are considered, and finally the most common and significant applications are described, with particular emphasis to the field of works of art.