Automated Determination of Optimum Excitation Conditions for Single and Multielement Analysis with Energy Dispersive X-Ray Fluorescence Spectrometry

The determination of optimal excitation conditions for energy dispersive x-ray fluorescence is particularly critical for multielement analysis covering a wide range (viz. 10 or 20 keV) of the spectrum. Functions that quantitatively describe the spectral quality are used as objective functions in pattern search algorithms. It is shown that the filters can be arranged in a definite order, at least with respect to the energy of the K-absorption edge of the tube and can therefore be employed as a dimension in the optimization process. Of the algorithms that were compared, the Nelder-Mead and Routh-Swartz-Denton versions of the sequential simplex search gave the best results if the excitation voltage and the current could be controlled in small increments. If the optimization includes dimensions with a few discrete stages (e.g. filters) the fixed size simplex proved to be of greatest value. The functions can be weighted to reflect special interest in one or more elements. Conditions for increasing the counting time and terminating the search are discussed.

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Automated Determination of Optimum Excitation Conditions for Single and Multielement Analysis with Energy Dispersive X-Ray Fluorescence Spectrometry

Advances in X-Ray Analysis ◽

10.1007/978-1-4613-9987-2_46 ◽

1979 ◽

pp. 433-451 ◽

Cited By ~ 4

Author(s):

Wolfhard Wegscheider ◽

Bruce B. Jablonski ◽

Donald E. Leyden

Keyword(s):

Multielement Analysis ◽

Energy Dispersive ◽

Fluorescence Spectrometry ◽

X Ray ◽

Excitation Conditions ◽

Automated Determination

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Automated determination of mercury and arsenic in extracts from ancient papers by integration of solid-phase extraction and energy dispersive X-ray fluorescence detection using a lab-on-valve system

Analytica Chimica Acta ◽

10.1016/j.aca.2009.05.034 ◽

2009 ◽

Vol 652 (1-2) ◽

pp. 148-153 ◽

Cited By ~ 27

Author(s):

M. Alcalde-Molina ◽

J. Ruiz-Jiménez ◽

M.D. Luque de Castro

Keyword(s):

Solid Phase Extraction ◽

Fluorescence Detection ◽

Solid Phase ◽

Energy Dispersive ◽

Phase Extraction ◽

X Ray ◽

Valve System ◽

Automated Determination

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“Standardless” Quantitative Analysis by Electron-Excited Energy Dispersive X-Ray Spectrometry: What is its Proper Role?

Microscopy and Microanalysis ◽

10.1017/s1431927600021097 ◽

1998 ◽

Vol 4 (S2) ◽

pp. 194-195

Author(s):

Dale E. Newbury

Keyword(s):

Quantitative Analysis ◽

Energy Dispersive ◽

K Value ◽

X Ray ◽

Electron Probe Microanalyzer ◽

Proper Role ◽

Wide Range ◽

Measured Characteristic ◽

Electron Range

The development of energy dispersive x-ray spectrometry (EDS) has had a profound impact on the methodology of quantitative x-ray microanalysis of thick specimens (i.e., thickness≫ electron range) as performed in electron beam instruments. By equipping the scanning electron microscope (SEM) with EDS, quantitative x-ray microanalysis has become commonly available to a wide range of users, at least some of whom have only a modest background in analytical science. An important aspect of the development of quantitative analysis by EDS has been the extensive analytical experience gained during the development of the electron probe microanalyzer (EPMA) equipped with wavelength dispersive x-ray spectrometers (WDS). The critical measurement step for quantitative WDS analysis was recognized to be the determination of the “k-value”:k = Iunk / Istd (1)where I is the measured characteristic intensity of a specific x-ray peak, corrected for background and peak overlaps, for both the unknown and the standard.

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Radioisotope-Excitation XRF Determination of Trace Elements in Marble

Applied Spectroscopy ◽

10.1366/0003702934066640 ◽

1993 ◽

Vol 47 (3) ◽

pp. 330-333 ◽

Cited By ~ 1

Author(s):

C. T. Yap

Keyword(s):

Trace Elements ◽

Energy Dispersive ◽

Fluorescence Technique ◽

X Ray ◽

Concentration Determination ◽

Wide Range ◽

Experimental Errors ◽

Radioactive Sources

The energy-dispersive x-ray fluorescence technique was employed to determine quantitatively the concentrations of trace elements in 22 pieces of thick marble of various sizes from Portugal and Thailand, with the use of the radioactive sources Fe-55, Cd-109, and Am-241 in order to cover a wide range of elements. The reliability of the concentration determination was confirmed by employing two different methods which gave the same quantitative values of iron within experimental errors. The following trace elements were found to be present in varying concentrations: manganese (0–244 ppm), iron (110–4104 ppm), copper (14–64 ppm), zinc (0–665 ppm), arsenic (0–27 ppm), strontium (100–335 ppm), and yttrium (0–12 ppm). It was found that, besides iron, which is responsible for the staining or coloring of marbles, manganese can cause dark streaks and colored patches and has values as high as 244 ppm. With the use of iron, yttrium, and strontium in a triangular plot, the pieces from Portugal and Thailand, respectively, divided into two well-defined groups which are well separated from each other, showing that it is possible to identify the origin of the marble pieces.

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Preparation And elemental analysis of ancient fibers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100126846 ◽

1987 ◽

Vol 45 ◽

pp. 410-411

Author(s):

Allen Angel ◽

Kathryn A. Jakes

Keyword(s):

Cross Sections ◽

Physical Structure ◽

Energy Dispersive ◽

Archaeological Sites ◽

X Ray ◽

Long Term Storage ◽

Backscattered Electron ◽

Electron Imaging

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.

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