X-ray fluorescence analysis has been used in the aluminum industry since the beginning of the 1950's. Initial applications involved predominantly raw materials such as bauxite. During the last decades its use expanded to every stage of aluminum production and today, XRF analysis is a recognized analyticaI technique, applied routinely in exploration, reduction and fabrication processes. Typical XRF applications in the aluminum industry at present are listed in Table 1. The number of determinations given represents usual industrial requirements, and may vary between laboratories. The sample preparation techniques are again the most commonly used for the applications.
Abstract
Three sample preparation techniques—thin-film, solution, and cellulose pellet—were applied to the determination of bromide in brominated lipids by X-ray fluorescence spectroscopy. Using brominated vegetable oils of known bromide content it was demonstrated that the thin-film technique could result in erroneously high bromide contents, which could also vary with the amount of oil applied, depending on the solvent used. As solutions in hexane, slightly high bromide contents were observed at high concentrations. With the cellulose pellets, bromide contents similar to known values were observed. It was concluded that the cellulose pellet procedure, although more time consuming, and less convenient for ready recovery of sample, was the most suitable for organic bromide determination. Similar results were indicated for chlorinated oils.
AbstractAnalysis schemes for eleven rare earths (Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb) taken singly in Y-Fe garnet powders are presented. Straight-line calibrations result in all cases, usually over a range from below 0.5 wt.% to better than 6 wt.%. Errors were held to ±5-10% even using extraordinarily simple sample preparation techniques. Data are presented relating to the effects of particle size and sample preparation on precision and accuracy of the resulting analysis.
This paper reviews the application of scanning electron microscopy and x-ray spectrometry to the examination of questioned documents that have been submitted to the author's laboratory. The use of the SEM is confined to examples where it can provide information unobtainable by alternative methods. This is demonstrated using a variety of examples including paper and printing ink analysis, and the examination of valuable documents, such as stamps. The strategy followed when attempting to determine the sequence of overlapping or intersecting writings is discussed. Special sample preparation techniques are explained and guidelines for optimizing instrumental conditions for different sample types are outlined.
X-ray fluorescence has been applied to the analysis of a wide variety of chemically treated cotton textiles. Sample-preparation techniques suitable for the determination of elements heavier than Na have been developed, and the effect of fabric structure on counting rate has been investigated. Selected examples of results obtained in the analysis of some 20 elements applied to cotton fabrics are given. The problem of particle size when the element is in the form of pigment is discussed.
Comparison of sample preparation techniques and matrix effects correction methods for X-ray fluorescence determination of total iron and rock-forming elements in iron ores