Showing papers on "Fluorescence spectrometry published in 1974"

Laboratory handbook of petrographic techniques

Abstract: Contents include: Thin-section preparation. Aids in thin-section study. Grain size, modal analysis, and photomicrography. Rotation methods for the polarizing microscope. Mineral separation, Powder methods of x-ray diffraction. Application of x-ray powder data to specific mineral groups. Specific gravity determination, Refractive index determination. X-ray fluorescence spectrometry. Atomic absorption spectrophotometry. Determination of chemical components not attainable by the foregoing methods. Display of data. Thermal analysis techniques. References. Appendix. Index. This handbook stresses the practical aspects of commonly-used petrographic techniques that are generally applicable to igneous and metamorphic rocks, Author is with the University of Malaya, Kuala Lumpur, Malaysia. -- AATA

X-ray fluorescence analysis — results of a first round intercomparison study

Abstract: The results are presented of an intercomparison study between twelve investigators and three analytical techniques. The objective was to determine the precision and accuracy with which multi-element analysis of air particulates on filters can be accomplished using energy dispersive X-ray fluorescence spectrometry. Special emphasis was placed on testing calibration techniques and methods of correction for absorption in both particulate deposits and substrates. Results indicate that errors in calibration and correcting for substrate absorption can be reduced to much less than 10% for elements K and above, but the more work is required to test methods of correcting for particles size to achieve 10% accuracy at energies below 3 keV.

Energy-Dispersive X-Ray Spectrometry for Multielement Pollution Analysis

Abstract: This paper outlines the elementary principles of energy dispersive X-ray fluorescence spectrometry with special reference to multielement analysis of pollutants. Typical equipment, using radioisotope sources for X-ray excitation, is described and some results are given for analysis of air particulates, wear debris in oils and suspended and dissolved solids in fresh water. The use of "thin" specimens is discussed for reducing interelement and particle size effects, increasing sensitivity and simplifying preparation of standards and samples.

Use of x-ray fluorescence for chemical analysis

Abstract: Major advances in X-ray fluorescence analysis during the last three years are reviewed. Considerable progress has been noted in the use of radioactive sources, small X-ray tubes and energy analysis by solid state detectors. Much of the review deals with published applications of X-ray fluorescence in chemical analysis. An attempt is made to forecast future developments and comparison with other analytical techniques suggests that X-ray fluorescence spectrometry will maintain, and possibly increase, its relative importance.

X-ray fluorescence spectrometry on variable thin deposits of powdered materials

Abstract: This work is aimed at providing a direct analytical method for powdered materials collected on cellulose filters. The origin and composition of these materials may be very different. The analytical technique employed was X-ray fluorescence spectrometry without preliminary treatment of samples. It is known that different thickness of thin deposits, due for example to different sampling condition, cause some difficulties on the correct accomplishment of the analysis. To eliminate this drawback the basic principles characterising the behaviour of X-ray penetration in the matter, were developed, thus leading to some equations, applicable to the analysis of the following kinds of samples: (a) sample of infinite thickness for X-ray penetration; (b) sample of finite thickness below the critical value; (c) sample of infinite thickness placed over the sample of finite thickness. The equation relating to case (c) was then applied to the analysis of powdered materials collected on cellulose filters. A suitable plate of a selected metal was placed over the sample, and the fluorescence radiations intensity values of the element to be analysed were recorded together with the intensity of the radiation emitted by the plate. By substituting some terms of the above mentioned equation with experimental data, X-ray intensity values were corrected, and then independent measurements were performed on the sample thickness. This work described both the theoretical part and the experimental procedures with results showing the method's reliability.

Determination of microgram quantities of sulphate in soil extracts by ion-exchange resin paper and X-ray fluorescence spectrometry

Abstract: A method that uses a combination of ion-exchange resin paper and X-ray fluorescence spectrometry for the rapid, specific determination of microgram quantities of sulphate in soil extracts is described.

Application de la Spectrométrie de Fluorescence X á la Mesure de l'Espace de Diffusion du Brome dans le Corps Humain

Abstract: Le volume de liquide extracellualaire (LEC) chez l'homme estun parameetre important pour la deetection de certins eetats pathologiques. La spectromeetrie de fluorescence X permet de mesurer avec une bonne preecision I'espace de deffusion de I'ion bromure et d'en deedrire la valeur du volume de LEC. La meethode consiste en un dosage direct du brome stabel (80Br) a faible concentration dans les liquides biologiques, en utilisant la raie Br Kα Une etude paralleele au moyen d'un radiotraceur (82Br)permet de tester la valcur de la meethode. Measurement of the extracellular fluid volume (ECFV) in the human body is an useful means of recognizing pathological conditions. X-ray fluorescence spectrometry allows a simple and accurate determination of the difusion space of bromide ions, from which the ECFV value can be calculated. The method consists of the quantitative determination of stable bromine (80Br) at low concentration in biological fluids, using the Br Kα line. A simultaneous study run with a radioactive tracer (82Br) allowed us to check the validity of the procedure.

A comparison of the gravimetric and x-ray fluorescence methods for the determination of sulfur in aqueous mixtures resembling seawater.

Abstract: The use of X-ray fluorescence spectrometry is described as a means of determination of total sulfur concentration of aqueous mixtures. The results of X-ray analyses of several types of solutions are compared to the results obtained by the gravimetric methods of barium sulfate precipitation. Sample pretreatment and handling were minimized by the X-ray method. Solutions containing sodium and chloride ion concentrations resembling those found in natural seawater were found to be especially amenable to total sulfur determination by X-ray fluorescence analysis.