A major area of application of x-ray fluorescence analysis in the chemical industry is the determination of heavy trace elements in organic substances, such as the toxic elements Pb, As, Cu, Ni, Hg, and Se in pharmaceutics and dyes, and contaminants such as Ti, Mn, Co, Zn, Sb, Cl, and Al which occur in the catalytical production of plastics. These contaminations can largely be determined without complicated sample preparation, and detection limits on the order of 10-6 (1 ppm) may be achieved. Matrix effects on the fluorescent intensities in the simultaneous analysis of various substances can usually be calculated numerically on the basis of the bulk chemical composition without taking recourse to specific standards, thus making possible a broad application to trace element analysis. X-ray fluorescence analysis may also be used to determine higher contents of heavy elements such as S, P, Cl, Br, and I, or of metal in organic matrices. Experiments to determine the C—H ratio of hydrocarbons from scattering intensities have been reported. A unique procedure for quantitative determination of organic molecules, which cannot be determined by x-ray fluorescence analysis, involves determination of the contents of heavy elements such as halogens, sulfur, or metals which are sometimes stoichio-metrically associated with the organic molecules.
KeywordsHeavy Element Bulk Chemical Composition Trace Element Determination Catalytical Production Copper Determination
Unable to display preview. Download preview PDF.