bluuebunny/crossref_metadata_2025_split huggingface dataset:
X‐ray fluorescence determination of trace elements in geological materials: An iterative approach to compton scatter corrections for matrix absorption
Authors: Harvey P. K. 
Published: May 2005

AbstractCompton scatter corrections are widely used for trace element determinations in geological materials where elements heavier than iron commonly occur only in low concentrations and whose effects on matrix absorption are usually ignored. Problems with the Compton correction for absorption can be seen if the concentrations of these trace elements become anomalously large, perhaps up to a few percent, although the effects can actually become significant at only a few hundred parts per million. When this occurs the simple absorption relationship, estimated at the Compton wavelength, becomes distorted. An iterative algorithm is presented that corrects absorption ratios at any wavelength as absorption edges are encountered during processing and in turn extends the Compton method to the accurate determination of anomalously high trace element concentrations.
X‐ray fluorescence analysis of rocks by the fundamental parameter method
Authors: Afonin V. P. , Finkelshtein A. L. , Borkhodoev V. J. , Gunicheva T. N. 
Published: May 2005

AbstractImprovements to the fundamental parameter algorithm of x‐ray fluorescence analysis are considered. The algorithm involves the following effects: primary and secondary x‐ray absorption, secondary and tertiary fluorescence, excitation by scattered x‐rays, excitation by photoelectrons and excitation by the divergent primary beam. The algorithm allows one to calculate the spectral intensity of x‐ray tubes with both thick and electron transmission targets. A version of the algorithm that can be handled on a low‐capacity computer is proposed. The algorithm was tested experimentally on the analysis of rocks, but its algorithm may be applied to different substances and materials.
Iodine determination in photographic fixers by energy‐dispersive x‐ray fluorescence
Authors: Morse Mark A. 
Published: May 2005

AbstractAn energy‐dispersive x‐ray fluorescence method is described for the determination of iodine in seasoned photographic fixing solutions. The method employs a cesium internal standard and is intended to cover a concentration range of ca. 80–4000 μg g−1 iodine. The precision [relative standard deviation (RSD)] of the iodine measurement was found to be 1.01% (1s) at the 2700 μg g−1 level. The RSD of the fixer sample preparation was determined to be 0.79% (1s). The limit of detection for iodine was calculated to be 8.7 μg g−1 (3s).
X‐ray analysis of thin GexCyOz: H films
Authors: Ebel M. F. , Ebel H. , Mantler M. , Wernisch J. , Svagera R. , Gazicki M. , Olcaytug F. , Schalko J. , Kohl F. , Jachimowicz A. 
Published: May 2005

AbstractInvestigations by means of x‐ray photoelectron spectrometry, electron probe microanalysis, x‐ray fluorescence analysis, imaging x‐ray fluorescence analysis, x‐ray diffraction and secondary ion mass spectrometry were performed to quantify thin GexCyOz: H films. The films were prepared by r.f. plasma deposition of tetraethylgermanium in a parallel‐plate system and in a two‐rod discharge system with magnetron enhancement. The results of these investigations indicated that depth profiling delivers a homogeneous composition, with the exception of the outermost surface. At a constant flow‐rate of tetraethylgermanium, the film density and the Ge/C atomic ration increase with increasing r.f. power density towards a maximum of 3.5 g cm−3 and 0.5, respectively. The hydrogen content does not change significantly. At low r.f. power densities there is a considerable increase in oxygen. There is no evidence for crystalline germanium carbide. Magnetron enhancement causes an increasing deposition rate and an inhomogeneous deposition in the lateral direction of the films.
X‐ray fluorescence intensity of an element in multicomponent ores and the use of compton radiation for matrix effect correction
Authors: Domi Nuri 
Published: May 2005

AbstractA theoretical justification of an equation in which the matrix effects are corrected using the Compton peak, for thick specimens, is proposed. For the sake of experimental assessment with the same set of specimens but different spectrometers (wavelength‐ and energy‐dispersive), an intercomparison between ten models used for the determination of iron, copper, zinc and lead in polymetallic ores is presented.
Accuracy of calibration procedure for energy‐dispersive x‐ray fluorescence spectrometry
Authors: Markowicz A. , Haselberger N. , Mulenga P. 
Published: May 2005

AbstractThe quality of a calibration procedure was studies in terms of the accuracy of the calibration factors. In particular, the influence of the uncertainties of the incident and emerging angles and of the mass absorption coefficients on the calibration factors was described theoretically for a calibration procedure based on standard samples of any thickness. The calculations were carried out for an x‐ray tube and a radioisotope excitation set‐up. Practical consequences of the inaccuracies of the calibration factors were also demostrated for a few test samples of intermediate thickness analysed by the emission–transmission method.
Calculation of x‐ray fluorescence and scattered primary radiation intensitie in x‐ray fluorescence analysis of powder slurry‐like materials
Authors: Finkelshtein A. L. , Gunicheva T. N. , Kalughin A. G. , Afonin V. P. 
Published: May 2005

AbstractAnalytical equations for calculating x‐ray fluorescence and scattered primary radiation intensities in x‐ray fluorescence analysis of slurries and slurry‐like materials are proposed. These equations are derived for the slurry model, in which the space distribution of the solid‐phase particles is described by Poisson's law. The computation results are compared with literature data and the authors' experience.
How accurate is the fundamental parameter approach? XRF analysis of bulk and multilayer samples
Authors: De Boer D. K. G. , Borstrok J. J. M. , Leenaers A. J. G. , Van Sprang H. A. , Brouwer P. N. 
Published: May 2005

AbstractThe accuracy of Fundamental Parameter‐based XRF quantification is investigated for both bulk and multilayer analysis. It is found that for bulk materials the relative accuracy is of the order of 1% and for multilayers a few percent. The method can be set up in such a way that it contains an inherent validity check. Further possibilities of the Fundamental Parameter method are discussed.
A low dilution fusion technique for the analysis of geological samples. 2—major and minor element analysis and the use of influence/alpha coefficients
Authors: Eastell J. , Willis J. P. 
Published: May 2005

AbstractA previously described low‐dilution fusion technique has been used successfully for the accurate determination of major and minor elements in geological samples. Three methods of calculating appropriate α coefficients have been investigated, namely (1) multiple regression analysis, (2) the Norrish and Hutton method and (3) a computer program, NBSGSC, involving fundamental parameters and the COLA equation. Methods (1) and (2) gave poor results for rock types of widely varying composition. The third method requires that the variation of α coefficients with varying weight fraction of the analyte element be taken into account when calculating such coefficients.
The fundamental parameter method for energy‐dispersive x‐ray fluorescence analysis of intermediate thickness samples with the use of monochromatic excitation
Authors: Wȩegrzynek Dariusz , Holyńnska Barbara , Pilarski Tomasz 
Published: May 2005

AbstractThe fundamental parameter method for correction for enhancement and absorption effects in the energy‐dispersive x‐ray fluorescence analysis of intermediate thickness samples using monochromatic excitation was evaluated. A simple means for the calculation of the concentration of an element in an unknown sample without using the iterative approach is proposed. Based on the derived equation, the influence of the higher Z sample components and their concentration levels on the enhancement correction factor was examined theoretically and tested experimentally. The concentration of an interfering element was found to have a stronger influence on the enhancement correction factor than the concentration level of the determined element. The method was tested experimentally using various two‐element standard samples and reference materials. The calculated concentrations were in good agreement with the known values.
X‐ray absorption near‐edge study of some rare earth complexes
Authors: Shrivastava B. D. , Katre S. S. , Srinivasulu K. , Joshi S. K. 
Published: May 2005

AbstractThe x‐ray L3 absorption edges of all cis‐1,2,3,4‐cyclopentanetetracarboxylic acid complexes of Gd, Tb, Dy and Ho were recorded with the help of a 400 mm Cauchois‐type bent crystal x‐ray spectrograph. The behaviour of the four lanthanide cations in the environment of the same complexing ligand was investigated. The chemical shifts were correlated with IR studies. Information regarding bonding in these complexes was obtained from the observed chemical shifts. A regular decrease was observed in the average metal—ligand bond distances with increasing atomic number of the metal ion in these complexes and this is interpreted in terms of metal—oxygen interaction.
EDXRF analysis of trace elements in Nerium oleander for pollution monitoring
Authors: Marques M. I. , Carvalho M. L. , Öblad M. , Amorim P. , Ramos M. T. 
Published: May 2005

AbstractBiomonitoring studies of elements (Ti, Mn, Fe, Cu, Zn, Br, Sr and Pb) in leaves of Nerium oleander were performed using energy‐dispersive x‐ray fluorescence spectrometry. The samples were collected at different locations in Lisbon, some with light and others with heavy traffic. The results were compared with those obtained for samples from the same species collected in an unpolluted region. Significant differences in the concentrations of some elements, particularly iron, titanium, zinc, strontium and lead, were found for samples from different locations. Titanium and iron concentrations had similar variations from one site to another with an almost constant ratio (Ti/Fe ≈︁ 0.2). The concentrations of lead were, as expected, higher at locations with heavier traffic.
A simple, inexpensive gas proportional scintillation counter for x‐ray fluorescence analysis
Authors: Dos Santos J. M. F. , Bento A. C. S. S. , Conde C. A. N. 
Published: May 2005

AbstractA simple, inexpensive, high‐performance gas proportional scintillation counter for x‐ray spectrometry is described. Energy resolutions below 9% are obtained with detector window diameters of less than 22 mm, for 5.9 keV Mn fluorescent x‐rays, even for a small window‐to‐sample distance where beam collimation is not effective. X‐ray fluorescence spectra are presented for biotite, pyrite/chalcopyrite and stainless‐steel samples.
EDXRF study of the effects of Cr on the growth of barley seedlings
Authors: Calliari I. , Concheri G. , Nardi S. 
Published: May 2005

AbstractEnergy‐dispersive x‐ray fluorescence spectrometry was used to determine Cr and bioessential trace elements (Fe, Zn, Cu, Mn) in the leaves and roots of barley seedlings. The thin‐film approach, secondary target excitation and microwave acid digestion were applied. The effects of Cr and other microelements on the growth of barley seedlings are discussed.
Differential scattering cross‐sections for 8 keV photons in kapton and crystalline targets
Authors: Karydas A. G. , Potiriadis C. , Paradellis T. 
Published: May 2005

AbstractThe model adopted for the calculation of the atomic scattering (Rayleigh or Compton) cross‐section in a material assumes that each atom scatters independently of the others (isolated or independent atomic model approximation). An investigation of the accuracy of this model was performed by measuring differential scattering (Rayleigh plus Compton) cross‐sections for 8 keV photons in a medium of low atomic number (Kapton) and in two crystalline targets (silicon and copper). The results for Kapton are in good agreement with theory but for the two crystalline targets there is a large discrepancy owing to diffraction phenomena. For this case, the influence of the crystal perfection of the target on the experimental scattered yield is discussed.
Determination of selected trace elements in silicates by electron and proton probe microanalysis
Authors: Sweeney R. J. , Jablonski W. , Sie S. H. 
Published: May 2005

AbstractThe elements Nb, Zr, Ta, Y, Ce, Nd, Lu, Ba and Sr were calibrated on a wavelength‐dispersive spectrometerequipped electron probe microanalyser (EPMA) using existing standards and a Ta‐bearing primary glass standard manufactured for Ta calibration. These calibrations were tested using a manufactured secondary glass standard doped with 600‐1800 ppm of these elements. The EPMA calibrations reproduced the glass secondary standard concentrations to within ±10% relative (except for Y) with detection limits of 40‒100 ppm. The accuracy of this technique was compared with that of proton‐induced x‐ray emission (PIXE) determinations on the secondary standard.
EXFIT—a computer code for processing energy‐dispersive X‐ray fluorescence spectra of environmental thin samples
Authors: Stoev Krassimir N. , Dlouhy Joseph F. 
Published: May 2005

AbstractProblems in the development and application of software for processing of environmental energy‐dispersive x‐ray fluorescence spectra of thin samples are reviewed. The main principles and requirements for the software are discussed. A new program, EXFIT‐8.10, was created to meet these requirements and is described in detail. It is capable of analyzing up to 50 elements simultaneously by combining results from up to 3 different excitation conditions. A set of supporting and post‐processing programs is also included. The main specifications of the software and possible ways for improvement are discussed.
Chlorine determination in photographic developer solutions using wavelength‐dispersive X‐ray fluorescence
Authors: Morse Mark A. 
Published: May 2005

AbstractA wavelength‐dispersive x‐ray fluorescence method is described for the determination of total chlorine in fresh and seasoned photographic developer solutions. The method uses a cadmium internal standard to correct for slight changes in the solution matrix and covers a concentration range of 15–500 mg l‒1 chlorine. Precision studies using the method resulted in a relative standard deviation (RSD) of 0.41% (1s) at the 200 mg l‒1 chlorine level and a RSD of 1.13% (1s) at the 50 mg l‒1 level. The limit of detection for chlorine was found to be 5 mg l‒1 and the limit of quantification was calculated as 15 mg l‒1.
Calculation of photo‐ and auger electron contribution to X‐ray fluorescence excitation of elements with low atomic number
Authors: Pavlinsky G. V. , Dukhanin A. Yu. 
Published: May 2005

AbstractThe contribution of photo‐ and Auger electrons generated in analyte material to the x‐ray fluorescence of elements with atomic numbers from Z = 5 (boron) to 9 (fluorine) was evaluated. The calculations were performed for different x‐ray tube anodes, window thicknesses and working regimes. This contribution to x‐ray fluorescence excitation increases rapidly with decreasing atomic number of the measured element and depends greatly on the sample composition and experimental conditions. In some cases the contribution may exceed 90%. This high value results from the absorption in the window and in the x‐ray anode tube material of the long‐wavelength component of primary radiation which is most effective in photoionization of element atoms. It follows from the calculations that at shorter wavelengths, e.g. for Na and Cu, the contribution of photo‐ and Auger electrons to the excitation of their fluorescence seems to be much less significant than that obtained in other work.
Study on journal distribution of publications in the field of X‐ray fluorescence analysis
Authors: Stoev K. N. 
Published: May 2005

AbstractThe distribution of the publications on x‐ray fluorescence analysis among different journals is discussed on the basis of frequency of citation in major review articles. Differentiation among major sub‐fields such as particle induced X‐ray emission, total‐reflection x‐ray fluorescence and synchrotron radiation induced X‐ray fluorescence is studied. A comparison with the results from a computer search in the Science Citation Index and INSPEC databases is presented. Important sources of new information in x‐ray fluorescence analysis are identified and discussed.
Analysis of X‐ray spectra by iterative least squares (AXIL): New developments
Authors: Vekemans B. , Janssens K. , Vincze L. , Adams F. , Van Espen P. 
Published: May 2005

AbstractThe functionality of the computer package AXIL (Analysis of X‐ray spectra by Iterative Least squares), suitable for the evaluation of energy‐dispersive X‐ray spectra, has been extended in a number of ways. First, a background modelling algorithm, based on the use of mutually orthogonal polynomials was introduced to replace the linear or exponential polynomials employed previously. Second, the Gaussian photopeak model employed in previous versions of the program was extended to include the non‐Gaussian parts of the characteristic peaks and related background contributions. Both innovations are shown to improve the performance of the spectrum evaluation procedure. Third, the user‐friendliness of the evaluation program was enhanced (a) by allowing a PC plug‐in MCA card to be directly controlled from within the program and (b) by extending the command‐interface to allow for repeated execution of series of commands by means of control loops. A brief description of these changes is given; as an application, the accurate evaluation of micro‐XRF images is discussed.
Near room temperature energy‐dispersive detectors processed on high‐purity silicon
Authors: Jalas P. , Sipilä H. , Eränen S. , Leinonen K. 
Published: May 2005

AbstractDiode detectors and silicon drift chambers were processed on TOPSIL high‐purity silicon of resistivity 7 kΩ cm. Their suitability for XRF spectroscopy, when cooled to −30°C, was evaluated. The efficiency for different x‐ray energies was calculated starting from the processing parameters used in manufacturing. Spectrum measurements were made in order to establish the mechanisms causing electrical noise and charge trapping. With an 18 mm2 active area detector it was possible to achieve an FWHM of 385 eV for the 55Fe source 5.89 keV peak and better than 300 eV with detectors of 1 mm2 area. Incomplete charge collection was found to be due to effects on the edge of the detector active area or in the implanted surface facing the radiation.
Application of partial least‐squares calibration methods in low‐resolution EDXRS
Authors: Urbański Piotr , Kowalska Ewa 
Published: May 2005

AbstractThe partial least‐squares calibration method was studied on some examples of EDXRS applications: determination of strontium and iron in samples of rock, determination of tin in plated deposits, measurements of ash and sulphur in powdered samples of coal and coating thickness gauging. The spectra of the PLS predictors and the scatter plots of the load and score vectors are presented and an analysis of their interpretation is made. A non‐linearity problem which appeared in some cases was approached either by pretreatment of the entry data or modification of the latent variable. Application of this calibration technique in EXDRS gives two main advantages: (i) it allows systematic factors influencing the final results to be included in the calculated model and (ii) it can provide a new insight into some aspects of the measurement methodology since the data in the following steps of the calibration procedure can be studied and analysed.
Glancing‐incidence x‐ray analysis of thin‐layered materials: A review
Authors: de Boer D. K. G. , Leenaers A. J. G. , van den Hoogenhof W. W. 
Published: May 2005

AbstractGlancing‐incidence x‐rays provide a wealth of possibilities for the analysis of thin layers and multilayers. This paper discusses reflectometry under both specular and non‐specular conditions, and also the combination with angle‐dependent x‐ray fluorescence. From these measurements information can be obtained on layer thickness, interface quality and compositional depth profile. First the historical development of glancing‐incidence x‐ray analysis is sketched. Then the physical principles of the interaction of glancing‐incidence x‐rays with samples which may contain rough interfaces are discussed. The equipment, which allows for both x‐ray fluorescence and reflectivity measurements, is also described. The possibilities are illustrated with a number of examples from the literature.
Total reflection x‐ray fluorescence analysis of light elements under various excitation conditions
Authors: Streli C. , Wobrauschek P. , Ladisch W. , Rieder R. , Aiginger H. 
Published: May 2005

AbstractTotal reflction x‐ray fluorescence (TXRF) analysis was tested for its suitability for the photon‐induced energy dispersiver analysis of light elements such as B, C, N, O, F, Na and Mg using a special spectrometer meeting the requirements for the detection of low‐energy fluorescence radiation. The influence of different spectral modification devices such as a high‐energy cut‐off reflector and a multilayer monochromator were compared using excitation by a Cr tube and also synchrotron radiation. The effects on intensity, background and detection lilmits are compared and discussed. A new method of monitoring the x‐ray beam to adjust total reflection by a CCD camera is introduced. Considerations on the penetration depth and information depth of light elements are presented.
Calculation of the x‐ray fluorescence intensity from heterogeneous substances by the Monte Carlo method
Authors: Gunicheva T. N. , Kalughin A. G. , Afonin V. P. 
Published: May 2005

AbstractA Monte Carlo simulation model for the computation of the x‐ray fluorescence intensity from heterogeneous substances is proposed. The geometric presentation used and its simulation provide an adequate description of the experimental data for slurries, alloys and powders with the same and different particle sizes for the fluorescent phase and the matrix. The total fluorescence flux is considered to consist of the first‐, second‐ and third‐order fluorescence. The adequacy of the model was estimated by comparison of the computational results with the experimental data and with calculation results from the analytical equations. The model made possible the evaluation of the magnitude of the enhancement and scattering effect contributions for different substances.
Non‐destructive x‐ray fluorescence analysis of soils and friable and marine sediments
Authors: Gunicheva T. N. , Aisueva T. S. , Afonin V. P. 
Published: May 2005

AbstractA procedure for the non‐destructive x‐ray fluorescence (XRF) spectrometric determination of major and some minor elements in soils, marine sediments and friable deposits is proposed. It does not require any preliminary treatment of the sample except for its drying at 105°C. The matrix correction procedure used is based on α‐ coefficients which are simulated for maximum possible variations of interfering element concentrations in the matrix and are calculated on the assumption that the sample is homogeneous. The achieved agreement between the XRF results and the certified values is satisfactory. The paper discusses why the above material cannot be homogenized by fusion and the effect of this on the XRF results.
White line in L absorption spectra of rare earths in their oxides and cuprates
Authors: Moghe Nitin V. , Sapre V. B. 
Published: May 2005

AbstractA method for curve fitting was used to study and compare the variation in the density of state responsible for the occurrence of the white line associated with the LII and LIII absorption discontinuities of rare earths in their oxides and cuprates. It is observed that the increased covalent character of the rare earth–oxygen bond in rare earth cuprate results in a decrease in the density of the final energy state responsible for the white line.