X-ray fluorescence, analysis using

N.V. Polosmak and V.A. Tmnova. An analysis of Pazyryk hair (X-ray fluorescent analysis using synclirotron radiation) //Archaeology, Ethnology Anthnoropology of Eurasia, 1(17) 2004, p. 73-71. 

Figura, P.M. 1987. Standardless quantitative X- ray fluorescence analysis using stored calibration constants. American Laboratory, 19(2), 156-164.

Jaklevic. J. M., Loo. B, W., and Goulding, F. S. (1977) Photon-Induced X-Ray Fluorescence Analysis Using Energy-Dispersive Detector and Dichotomous Sampler, in Dzubay. T. G. (Ed.), X-Ray Fluorescence Analysis of Environmental Samples, Ann Arbor Science Publishers, Ann Arbor, MI. 

Muminov, V., Haidarov, R 1980. Rentgenofluorescentnyi Analiz Vozbuzhdeniem Uskorennyimi Legkimi lonami (X-Ray Fluorescence Analysis Using Excitation with Accelerated Ions). Fan, Tashkent, p. 171. 

X-ray fluorescence analysis using vacuum tube sources have become a well-established analytical technique in the last decade. Nuclear interest stems partly from the possibility of using radioactive sources for stimulating X-ray fluorescence in a sample. These sources can be classifled depending on the mode of production of the X-rays ... 

XRF-ED X-ray fluorescence analysis using energy dispersive detection. 

Left panei Schematic of the experimental set up for confocal 3D-XRF at the European Synchrotron Radiation Facility (ESRF) iD18F end-station. Right panel Basic principle of confocal X-ray fluorescence analysis using polycapillary detector optics (Adapted from Vincze et al. 2004)... 

One additional process of interest is fluorescence where the incoming X-ray photon is used to eject an electron (called photoelectron ) from the inner atomic shells this process creates a hole which is filled by an electron from the outer shells. The energy excess is then emitted as characteristic photon. X-ray fluorescence analysis uses this photon energy to identify the various elements present in a material with detection limits down to parts per million in some cases. A related process resulting from the photon/electron interaction is the Auger electron emission (discussed in details elsewhere in this book). 

With the development of solid-state detectors of improved resolution, the application of energy-dispersive X-ray fluorescence analysis, using radioisotope or X-ray tube excitation, is extending rapidly. Sensitivities of a few ppm on simple matrices (e.g., organic materials) have been obtained. The energy-dispersive method offers economical means of analysis for a wide range of materials, including metals, ores, and solid atmospheric pollutants. 

Mineral and Chemical Composition. X-ray diffraction is used to determine the mineral composition of an Mg(OH)2 sample. Induced coupled plasma (icp) spectrophotometry is used to measure the atomic concentrations present in a sample. X-ray fluorescence analysis is another comparative instmmental method of determining chemical composition. 

Spectroscopic methods for the deterrnination of impurities in niobium include the older arc and spark emission procedures (53) along with newer inductively coupled plasma source optical emission methods (54). Some work has been done using inductively coupled mass spectroscopy to determine impurities in niobium (55,56). X-ray fluorescence analysis, a widely used method for niobium analysis, is used for routine work by niobium concentrates producers (57,58). Paying careful attention to matrix effects, precision and accuracy of x-ray fluorescence analyses are at least equal to those of the gravimetric and ion-exchange methods. 

At X-ray fluorescence analysis (XRF) of samples of the limited weight is perspective to prepare for specimens as polymeric films on a basis of methylcellulose [1]. By the example of definition of heavy metals in film specimens have studied dependence of intensity of X-ray radiation from their chemical compound, surface density (P ) and the size (D) particles of the powder introduced to polymer. Have theoretically established, that the basic source of an error of results XRF is dependence of intensity (F) analytical lines of determined elements from a specimen. Thus the best account of variations P provides a method of the internal standard at change P from 2 up to 6 mg/sm the coefficient of variation describing an error of definition Mo, Zn, Cu, Co, Fe and Mn in a method of the direct external standard, reaches 40 %, and at use of a method of the internal standard (an element of comparison Ga) value does not exceed 2,2 %. Experiment within the limits of a casual error (V changes from 2,9 up to 7,4 %) has confirmed theoretical conclusions. 

The procedure of determination of metals in the thin layer without elimination of the non-volatile organic components for different paints containing inorganic pigments was developed. Several techniques of sampling from paint-and-lacquer materials for X-ray fluorescence analysis were proposed. For the study of nonhomogenity of metal distribution in the thin layer we used additionally the local method of X-ray fluorescence analysis. 

X-RAY FLUORESCENCE ANALYSIS OE COAL CONCENTRATES USING QUASI-SOLID SPECIMENS... 

Over the last seventeen year s the Analytical center at our Institute amassed the actual material on the application of XRF method to the quantitative determination of some major (Mg, Al, P, S, Cl, K, Ti, Mn, Fe) and trace (V, Cr, Co, Ni, Zn, Rb, Sr, Y, Zr, Nb, Mo, Ba, La, Ce, Pb, Th, U) element contents [1, 2]. This paper presents the specific features of developed techniques for the determination of 25 element contents in different types of rocks using new Biaiker Pioneer automated spectrometer connected to Intel Pentium IV. The special features of X-ray fluorescence analysis application to the determination of analyzed elements in various types of rocks are presented. The softwai e of this new X-ray spectrometer allows to choose optimal calibration equations and the coefficients for accounting for line overlaps by Equant program and to make a mathematic processing of the calibration ai ray of CRMs measured by the Loader program. 

X-Ray Fluorescence analysis (XRF) is a well-established instrumental technique for quantitative analysis of the composition of solids. It is basically a bulk evaluation method, its analytical depth being determined by the penetration depth of the impinging X-ray radiation and the escape depth of the characteristic fluorescence quanta. Sensitivities in the ppma range are obtained, and the analysis of the emitted radiation is mosdy performed using crystal spectrometers, i.e., by wavelength-dispersive spectroscopy. XRF is applied to a wide range of materials, among them metals, alloys, minerals, and ceramics. 

X-ray fluorescence analysis is a nondestructive method to analyze rubber materials qualitatively and quantitatively. It is used for the identification as well as for the determination of the concentration of all elements from fluorine through the remainder of the periodic table in their various combinations. X-rays of high intensity irradiate the solid, powder, or liquid specimen. Hence, the elements in the specimen emit X-ray fluorescence radiation of wavelengths characteristic to each element. By reflection from an analyzing crystal, this radiation is dispersed into characteristic spectral lines. The position and intensity of these lines are measured. 

Chemical Analysis. The chemical composition of ancient objects is important for their authentication. The nature as well as the relative amounts of major, minor, and trace elements in any object are of use for determining the authenticity or otherwise of ceramics, glass, or alloys. A wide range of analytical techniques, depending on the nature of the material studied, have been used for this purpose, including X-rays fluorescence analysis, mass spectrometry, atomic absorption spectroscopy, and neutron activation analy-... 

Other techniques that have been used include subtractive differential pulse voltammetry at twin gold electrodes [492], anodic stripping voltammetry using glassy-carbon electrodes [495,496], X-ray fluorescence analysis [493], and neutron activation analysis [494],... 

Williams-Thorpe, O., Potts, P. J., and Webb, P. C. (1999). Field-portable non-destructive analysis of lithic archaeological samples by X-ray fluorescence instrumentation using a mercury iodide detector Comparison with wavelength-dispersive XRF and a case study in British stone axe provenancing. Journal of Archaeological Science 26 215-237. 

Table 14.11 Types of X-ray spectrometers used for X-ray fluorescence analysis... 

In a laboratory generator, electrons are accelerated by a potential around 30 kV towards a solid target, where they are stopped by impact. The output contains the line spectmm superimposed upon a continuous spectrum. The line, or characteristic spectrum is characteristic of the element and is used in X-ray fluorescent analysis to identity the type and amount of an element present in a sample. The continuous radiation is also called the Bremsstrahlung, from the... 

The primary dispersion halo and wallrock alteration around the Elura deposit was established from integrated petrographic, mineralogical and geochemical (major-, minor- and trace-element) analysis of diamond drill core samples. Seventy eight samples of variably altered and unaltered host rocks, as well as 67 near-surface weathered equivalents, were analysed for major elements using fusion disc. X-ray fluorescence analysis (XRF). Trace elements were determined by pressed powder XRF analysis. Carbonate carbon... 

The filter material of choice is a thin teflon membrane since it minimizes artifact formation and maximizes analytical sensitivity by X-ray fluorescence analysis. Although X-ray fluorescence (XRF) may not be the only analytical technique used, it is generally accepted as being the most cost effective analysis for source apportionment. ( 2) Its background and therefore, analytical sensitivity, is dependent on the filters surface density. The analytical sensitivity of XRF for aerosols deposited on a stretched teflon membrane with a density of about 0.3 to 0.4 mg/cm, for example, is about three times greater than an aerosol deposited on a cellulose based filter with a surface density of about 4 mg/cm. This difference can be translated into either more information for the same analytical costs or the same information for a lower analysis cost. 

The analysis of 0-aluminas for stable cations can be made by a fusion process. The 0-alumina can be dissolved in molten Li2C03 (or K2C03), the resulting glass dissolved in dilute nitric acid, and the solution analyzed by atomic adsorption. Activation analysis or X-ray fluorescence analysis also can be used. 

The discussion thus far has focused on the elemental composition of particles, which can be determined using such techniques as neutron activation or X-ray fluorescence analysis (see Chapter 11). One of the questions of increasing interest is the chemical form in... 

Membrane filters are particularly useful when surface analytical techniques, such as optical and electron microscopy and X-ray fluorescence analysis, are to be used subsequent to collection, because most of the particles remain on the surface of the filter. 

A second method of determining major and minor element abundances in meteorites is X-ray fluorescence analysis. In this method, a sample of meteorite is ground into a fine powder and irradiated by a monochromatic X-ray beam. The atoms in the sample absorb some of the X-rays, causing electrons to be ejected. The ejection of an electron causes other electrons to drop to lower energy levels to fill the vacancy, and characteristic X-rays are emitted. The X-ray energies are unique to each element and permit the chemical composition to be determined. X-ray fluorescence was used to determine the compositions of meteorites in the late 1950s and 1960s. If done correctly the compositions have the same accuracy as wet chemical analyses, but some of the measurements in the literature have problems with alkali elements. 

The certification procedure for seven trace metals (Ba, Ca, Li, Mg, Mn, Na and Sr) in the certified reference material FEBS-1 (National Research Council Canada, Institute for National Measurement Standards, Ottawa, Canada) based on fish otolith matrix by isotope dilution - ICP-MS in comparison to ICP optical emission spectrometry and X-ray fluorescence analysis, is described by Sturgeon et al4X The isotope dilution technique is also employed for species analysis in biological systems,46 e.g., for the determination of mercury species in tuna material,54 or in aquatic systems using cold vapour ICP-MS.55... 

The most frequently applied analytical methods used for characterizing bulk and layered systems (wafers and layers for microelectronics see the example in the schematic on the right-hand side) are summarized in Figure 9.4. Besides mass spectrometric techniques there are a multitude of alternative powerful analytical techniques for characterizing such multi-layered systems. The analytical methods used for determining trace and ultratrace elements in, for example, high purity materials for microelectronic applications include AAS (atomic absorption spectrometry), XRF (X-ray fluorescence analysis), ICP-OES (optical emission spectroscopy with inductively coupled plasma), NAA (neutron activation analysis) and others. For the characterization of layered systems or for the determination of surface contamination, XPS (X-ray photon electron spectroscopy), SEM-EDX (secondary electron microscopy combined with energy disperse X-ray analysis) and... 

GD-OES (glow discharge optical emission spectrometry) are applied. AES (auger electron spectroscopy), AFM (atomic force microscopy) and TRXF (transmission reflection X-ray fluorescence analysis) have been successfully used, especially in the semiconductor industry and in materials research. 

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