Solid Sample Preparations and Applications for X‐Ray Fluorescence Analysis

Abstract

X‐ray fluorescence (XRF) spectrometry is routinely employed for the simple and convenient determination of the content of the major and minor elements composing solid and powdered samples without the need to dissolve the samples. Along with developments in instrument components and analytical techniques, spectrometers have become increasingly smaller and automated. Modern XRF instruments are used by nonspecialists in various fields as well as by experienced analysts; these nonspecialist users may have little knowledge of analytical techniques and may omit to verify their results or may not be aware of the effect that the methods used to prepare their samples can have on the results. The accuracy of the results obtained using XRF largely depends on the properties of the samples, including the flatness, particle size, homogeneity, and thickness. These sample conditions for the reliable determination can be identified by the escape depth, i.e. analytical depth, of fluorescent X‐rays. This article describes the preparation of solid and powdered samples for use in XRF analysis in which the escape depth is taken into consideration. Studies in which loose powder, powder pellet, and glass bead specimens were prepared from such samples are then reviewed. The use of calibration curves derived using synthetic standards that have been prepared from chemical reagents containing analytes is also described, and studies in which analysis techniques based on calibration curves were evaluated using reference materials are also reviewed.