Wavelength dispersive X-ray spectrometry

The electron-optical performance of the EPMA system is indistinguishable from that of a conventional scanning electron microscope (SEM) thus, EPMA combines all of the imaging capabilities of a SEM with quantitative elemental analysis using both energy- and wavelength-dispersive X-ray spectrometry. ... 

Wavelength dispersive X-ray spectrometry (WDS) for a more detailed elemental analysis of samples in the SEM. JEOL Four-Crystal Spectrometer attached to the JSM-35C SEM can be used for l-pm spot analysis, digital and analog line scans, and X-ray image mapping, elements detection from Be to U, minimum detection limit of 0.01% by weight, fully quantitative results by extended cp-p-z. 

Table 11.5 Analyzing crystals used in wavelength-dispersive X-ray spectrometry.

In order to individually analyze the fluorescent X-rays from each element, the spectral separation of the X-rays is required. There are two types of spectrographic methods for XRF. They are wavelength dispersive X-ray spectrometry (WDS, WDX) and energy dispersive X-ray spectrometry (EDS, EDX). The characteristics of WDS and EDS are shown in Table 1. Please refer to the following reference for more detailed explanations of XRF [1]. 

Wavelength-dispersive X-ray spectrometry Method for qualitative and quantitative elemental analysis using the wavelengths of characteristic X-ray emission... 

FCC feedstocks contain sulfur in the form of organic-sulfur compounds such as mercaptan, sulfide, and thiophenes. Frequently, as the residue content of crude oil increases, so does the sulfur content (Table 2-5). Total sulfur in FCC feed is determined by the wavelength dispersive x-ray fluorescence spectrometry method (ASTM D-2622), The results are expressed as elemental sulfur. 

Taggart JE Jr, Lindsay JR, Scott BA, Vivit DV, Bartel AJ, Stewart K C (1993) Analysis of geological materials by wavelength-dispersive X-ray fluorescence spectrometry. In Badecker PA, ed. U.S. Geological Survey Bulletin 1770. Methods for Geochemical Analysis, pp E1-E19. 

Table 8.38 Main features of wavelength-dispersive X-ray fluorescence spectrometry (WDXRF)...

Nickel and vanadium along with iron and sodium (from the brine) are the major metallic constituents of crude oil. These metals can be determined by atomic absorption spectrophotometric methods (ASTM D-5863, IP 285, IP 288, IP 465), wavelength-dispersive X-ray fluorescence spectrometry (IP 433), and inductively coupled plasma emission spectrometry (ICPES). Several other analytical methods are available for the routine determination of trace elements in crude oU, some of which allow direct aspiration of the samples (diluted in a solvent) instead of time-consuming sample preparation procedures such as wet ashing (acid decomposition) or flame or dry ashing (removal of volatile/combustible constituents) (ASTM D-5863). Among the techniques used for trace element determinations are conductivity (IP 265), flameless and flame atomic absorption (AA) spectropho-... 

Microprobe techniques, and their detection limits (given in mgkg ), that have been applied to Al localization include energy dispersive (electron probe) X-ray microanalysis (20), wavelength-dispersive X-ray microanalysis, electron energy loss spectrometry (500), proton probe nuclear microscopy (10), resonance ionization mass spectrometry (3), secondary ion mass spectrometry (1), laser microprobe mass spectrometry (1) and micropartide-induced X-ray emission (Yokel 2000). 

WD-XRF wavelength dispersive-X-ray emission spectrometrywhich is visible microscopically siderosis deposition of iron in tissues and organs WHO World Health Organisation widy sign a dark pigment precipitation in hair roots at the fourth or fifth day after the intake of a toxic dose of thallium Wilson s disease recessive autosomal, hereditary disease (if untreated, results in invalidity and death) in which toxic amounts of copper are accumulated in the liver and central nervous system XPS X-ray photoelectron spectrometry XRF X-ray fluorescence spectrometry... 

X-ray spectrometry (XRF) is a versatile, fast, and accurate instrumental method for elemental analysis in a wide variety of materials. The performance of three different XRF systems will be compared a high power wavelength dispersive x-ray spectrometer (WDXRF), a low-power WDXRF, and a bench-top energy dispersive instrument (EDXRF). 

See also Atomic Absorption Spectrometry Flame Electrothermal. Atomic Emission Spectrometry Inductively Coupled Plasma. Color Measurement. Forensic Sciences Paints, Varnishes, and Lacquers. Gas Chromatography Pyrolysis. Infrared Spectroscopy Industrial Applications. Liquid Chromatography Size-Exclusion. Paints Water-Based. Spectrophotometry Organic Compounds. X-Ray Absorption and Diffraction X-Ray Diffraction - Powder. X-Ray Fluorescence and Emission Wavelength Dispersive X-Ray Fluorescence Energy Dispersive X-Ray Fluorescence. 

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