bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparative study of techniques for quantitative analysis of the X‐ray spectra obtained with a Si(Li) detector
Authors: Statham Peter John 
Published: May 2005

AbstractWith the appropriate excitation, a specimen will emit an X‐ray spectrum where the characteristic line intensities are strongly dependent on the elemental composition. The measurement of these intensities thus affords a method of accurate quantitative elemental analysis. A digitized record of the spectrum may be obtained using a lithium drifted silicon detector, associated electronics and some storage medium. The recorded data is the original spectrum convoluted by the appropriate instrumental function. This paper describes several procedures which may be applied to this data to obtain accurate estimates of the individual X‐ray line intensities, mainly with reference to the spectra obtained by electron excitation of thick specimens. The choice of a particular procedure depends on the quality of the data acquistion system, and the likely systematic errors which have been calculated for illustrative examples with special reference to the effects of drift and resolution changes in the electronics. Background subtraction techniques involving interpolation, extrapolation and filtering are discussed, together with methods for deconvolution of overlapping peaks, in particular least squares regression. A versatile new procedure, iterative stripping, is presented which simultaneously accomplishes background subtraction and peak deconvolution.
Determination of yttrium and niobium on standard silicate rocks by X‐ray fluorescence analyses
Authors: Leoni L. , Saitta M. 
Published: May 2005

AbstractEleven international standards [U.S.G.S. Standards. G‐2, GSP‐1, AGV‐1 and BCR‐1; C.R.P.G. standards: GA, GH, BR and Mica‐Fe; A.N.R.T. standard: DR‐N; G.S.J. standards: JG‐1 and JB‐1] have been analysed by X‐ray fluorescence for niobium and yttrium. Coefficients for full matrix effect correction are reported.
A practical method for the accurate analysis of high alloy steels by X‐ray emission
Authors: Caldwell Vincent E. 
Published: May 2005

AbstractA method for the conversion of X‐ray intensities to composition is given. The method is based on the Lachance‐Traill equation which uses empirical inter‐element correction coefficients. The coefficients are treated as ‘sliding constants’ the values of which depend on the relative concentrations of the analyte and the interfering elements. Values for the coefficients are calculated over wide concentration ranges using the theoretical equations of Sherman. The calculated coefficients are adjusted empirically to achieve high accuracy.Only the measured X‐ray intensities from the sample and a single standard are required for an analysis. Final results are obtained by solving a set of simultaneous linear equations. Results of analyses of high alloy steels containing Cr, Ni, Mn, Mo, Cu, Si, Ti, Cb and Fe are given to illustrate the accuracy of the method.
Folding of aerosol loaded filters during X‐ray fluorescence analysis
Authors: Van Grieken R. E. , Adams F. C. 
Published: May 2005

AbstractFolding aerosol loaded filters in two with the loaded side inwards during the X‐ray analysis not only reduces possible filter heterogeneity effects and improves sample protection, but also increases the sensitivity and renders filter paper absorption corrections simple and more accurate in many instances. It is shown that folding an aerosol loaded Whatman filter paper during Kα X‐rays counting leads to an increased sensitivity for all elements up from calcium, scandium or titanium (depending on the sensitivity definition and on the aerosol load) and for all elements up from phosphorus, sulphur or chlorine in the case of the Nuclepore filter. Although the absorption by the filter, into which the aerosol penetrates to some extent, is always more important in the sandwich than in the usual geometry, the dependence of the absorption correction on the usually unknown average deposition depth is less pronounced. Assuming all the aerosol material to be collected at the very surface of the filter and hence being present in the centre of the sandwich to be analysed, leads to an extremely simple filter paper absorption correction which is less prone to uncertainties than more sophisticated corrections in the usual geometry requiring additional measurements. This is the case for all elements up from potassium on Whatman filters and up from phosphorus on Nuclepore filters.
A system for routine analysis of chlorine, sulphur, potassium and calcium in brine by X‐ray fluorescence spectrometry applying theoretical matrix corrections
Authors: van den Enk Jan E. , Janssen Jan J. , de Jongh Willy K. 
Published: May 2005

AbstractA rapid procedure for the accurate determination of Cl, SO4, K and Ca in brines has been developed. The brine sample as received is put into a liquid sample holder and analysed by the PW 1410 X‐ray spectrometer with a helium attachment. The data are processed by an on‐line desk calculator HP 9830A. The elements mentioned strongly influence each other's X‐ray intensities and, consequently, matrix corrections have to be applied. The influence coefficients used for corrections are derived from physical data and give excellent results in that all calibration equations are perfectly linearized. The two instrument‐dependent calibration constants for each element are very stable in time and agree well between our three instruments of the same type. This stability is ensured by applying a monitor standard (pressed powder); thus, the occasional recalibration work is minimized. The precision for each element is better than 0.4% relative at a 95% confidence level and for a measuring time of about forty seconds per element. The calculated concentrations are in weight fractions, which are finally transformed to grams/litre or equivalents/litre. The specific gravity required for this transformation is calculated from the weight fractions.
The equivalent wavelength notion: Definition, properties, applications
Authors: Tertian R. , Vié Sage R. Le 
Published: May 2005

AbstractThe subject of a monochromatic radiation strictly equivalent to a given polychromatic spectral distribution is developed in accordance with usual analytical practice (e.g. by referring to relative intensities) assuming that (1) the polychromatic distribution can be any one, i.e. a continuous or discontinuous white spectrum, possibly including characteristic lines or not; (2) the fluorescent element is engaged in a homogeneous sample and is subject only to pure absorption effects (whether positive or negative) on the part of its neighbour elements. Important conclusions can then be derived.These are (a) the existence for each composition of one, and only one, equivalent wavelength λe, the origin and mathematical determination of which are accurately described; (b) the fact that λe systematically decreases with increasing fluorescent element concentration in binary compositions, whatever the associate element, whether it be a positive or negative absorber. This property then clearly extends to any given matrix; (c) the existence of a simple relation of equivalence between absorbers, enabling us to consider any absorber and then any absorbing matrix in terms of ‘equivalents’ if we so choose; (d) as a consequence of (b) and (c), a novel description of influence coefficients for the absorption case, accounting for their systematic variation with fluorescent element concentration and introducing a definite correlation between coefficients belonging to different absorbers; (e) further interesting properties such as the effect of the ‘geometry’, as well as the effect of dilution, on the situation of equivalent wavelengths and the values of influence coefficients. In so far as absorption effects are considered all the facts of X‐ray fluorescence as induced by polychromatic excitation are covered by the present theory.
Iterative procedures in electron probe analysis corrections
Authors: Springer G. 
Published: May 2005

AbstractThe simple, Wegstein and hyperbolic procedures of iteration are compared and shown to differ only in the ways in which the derivative of the correction factor with respect to concentration are calculated. The simple and hyperbolic methods are demonstrated either to provide slow convergence in certain cases or to lead to wrong values, or even to show divergence. The Wegstein procedure is recommended as being, in general, the fastest and most reliable method.
A systematic error in energy dispersive microprobe analysis of Ni in steel due to the method of background subtraction
Authors: Malm Staffan 
Published: May 2005

AbstractExperiments and a literature survey both show that energy dispersive microprobe analysis of Ni in steel generally gives substantial negative errors. This situation has been related to significantly lower X‐ray intensity ratios, k values, from an energy dispersive spectrometer system compared with a conventional wavelength dispersive spectrometer. Lower Fe contents in the specimens have been shown to give decreasing errors, which appear to be independent of the ZAF correction calculations.It is suggested that the systematic error for Ni is caused by the method of background subtraction, which seems to reduce the Ni Kα area. The error can be minimized if peak‐height intensities are used and if the background level is measured and subtracted manually.
Determination of copper concentration in aqueous and organic phases from solvent extraction processes by X‐ray fluorescence spectrometry
Authors: Harris A. M. , Baines D. F. 
Published: May 2005

AbstractAn X‐ray fluorescence method has been developed to determine the metal concentration in the aqueous and organic phases from solvent extraction processes. The method has been specifically applied to the determination of copper, but can be extended to include other elements which form soluble organic complexes. Accuracy and precision are comparable with that obtainable by the electrogravimetric technique for the analysis of copper in aqueous solution, but are superior to the atomic absorption analysis of copper in organic solution. Rapid analysis is achieved by presenting a diluted sample directly to the spectrometer. Inter‐element absorption enhancement effects are corrected by the selection of a suitable internal standard which is added to the diluent.
A correction method for scattered background intensity of target elements in fluorescent X‐ray spectrometry
Authors: Murata Michihiro 
Published: May 2005

AbstractA method for correcting scattered fluorescent X‐ray radiation arising from contaminants in a target of an X‐ray tube is described. The universal correction factor was obtained by measuring the intensity ratio of a characteristic radiation of an analytical element to a background radiation on a reference standard which contains none of the analytical element. The correction was performed by subtracting the intensity ratio of the reference standard from that of a sample. The method requires no calculation of correcting factors.
Data acquisition and control of wavelength and energy dispersive X‐ray spectrometers using a single minicomputer
Authors: Leyden D. E. , Lennox J. C. 
Published: May 2005

AbstractA laboratory minicomputer has been interfaced to both a wavelength dispersive X‐ray fluorescence spectrometer and an energy dispersive Si(Li) X‐ray detector system. In the former mode of operation, the computer is used as a controller for the setting of the goniometer, initiation of count cycle and data acquisition. In the second case, the computer serves as a substitute for the conventional multi‐channel analyzer, acquiring spectral information from an ADC associated with the energy dispersive detector. In both modes of operation, data obtained may be displayed on either an oscilloscope or X‐Y recorder. All data obtained can also be transferred to cassette storage for subsequent retrieval and data reduction in higher level programming languages such as BASIC or FORTRAN.
The use of computers in X‐ray fluorescence analysis
Authors: Gunn Bernard M. 
Published: May 2005

AbstractThe cheapness of modern minicomputers coupled with the need for rapid and accurate output of X‐ray fluorescence analytical data makes the use of computers almost obligatory. The minicomputer has the advantages of immediate availability of results over other methods. In laboratories with an annual output of less than 10 000 determinations the on‐line card ‐punch or magnetic‐tape reader coupled through a terminal to a central computer is equally effective though slower.
Enhancement effects in X‐ray fluorescence analysis of rocks
Authors: Franzini M. , Leoni L. , Saitta M. 
Published: May 2005

AbstractUtilizing artificially prepared powder pellets of samples, enhancement effects have been evaluated between the following pairs of elements: FeCa, FeSi, CaSi and SiAl. The experimental data suggest that in X‐ray fluorescence analysis of powdered rocks, for the considered elements over a very large range of concentrations, the enhancement effect can be regarded as a negative absorption.
A simplified fundamental parameters method for quantitative energy‐dispersive X‐ray fluorescence analysis
Authors: Shen R. B. , Russ J. C. 
Published: May 2005

AbstractStephenson's CORSET method has been adapted and expanded to the newer energy‐dispersive method to take advantage of its ability simultaneously to detect all elements (Z > 10) present (anticipated or not). Parameters such as the mass absorption coefficients and energies of absorption edges and emission lines of all elements are calculated as in Myklebust and Heinrich's FRAME program. The X‐ray intensities of pure elements versus atomic number of the elements for a given line (Kα or Lα) forms smooth curves as reported by Blum and Brandt. Because of the exceptional stability of energy‐dispersive methods (no moving parts, long tube life, etc.) and known overall spectrometer efficiency of these systems, they can be ‘standardized’ at installation by measuring (for a given tube, voltage and specimen holder configuration) several pure intensities (e.g. 6–10 covering the periodic table). Stored, these constants allow the calculation of the effective pure element intensity and the original intensity of the most effective excitation energy for any element that may be encountered. For an unknown sample, the program integrates net peak intensities (stripping away spectrum background and peak overlaps) and converts them to percentages with an iterative calculation. The accuracies are not as good as can be achieved with appropriate multiple standards. The compensating advantages are speed, flexibility and convenience. The entire program runs on‐line in a 16K, 16 bit minicomputer.
Proton‐induced X‐ray production in vanadium, iron, zinc, gallium, yttrium, cadmium, indium and tin
Authors: Rashiduzzaman Khan Md. , Hopkins A. G. , Crumpton D. , Francois P. E. 
Published: May 2005

AbstractMeasurements have been made of K X‐ray production from elements bombarded with protons. The X‐ray yields have been measured from thick targets of V, Fe, Zn, Ga, Y, Cd, In and Sn as a function of proton energy in the range 1–3 Me V. K‐shell ionization cross‐sections have been derived from the experimental data and these have been compared with the results of other workers and the predictions of the plane wave Born approximation (PWBA) and the binary encounter approximation (BEA).
A background correction for energy‐dispersive X‐ray analysis of thin sections
Authors: Sherry William M. , Vander Sande John B. 
Published: May 2005

AbstractThe ionization cross‐section of Kramers and the Thomson–Whiddington law have been used in the development of a background correction for quantitative electron microprobe analysis of thin sections employing an energy‐dispersive X‐ray detector. An expression has been derived which describes the X‐ray continuum emitted from a thin specimen while being irradiated with an energetic beam of electrons. The functional form of the expression describing the emitted continuum reduces to the equation derived by Kramers when specimen absorption is neglected. Theory demonstrates that for specimens of 2140 Å in thickness, a maximum difference of 16% exists between the continuum intensities predicted assuming absorption and neglecting absorption when working at an operating potential of 15 kV. Generally good agreement between the predicted emitted continuum and that measured from aluminum thin films is found.
Photographic recording of the spatial distribution of elements using an unmodified, flat‐crystal X‐ray spectrometer
Authors: Livingstone A. 
Published: May 2005

AbstractUsing simple constructional methods a special secondary collimator has been made from mica sheets and domestic aluminium foil which permits spectral images to be easily recorded (see Appendix). The collimator fits into the normal dual collimator tunnel of a commercial flat‐crystal spectrometer and instrument modification is unnecessary. A special film‐holding device ensures the spectral images are true to shape and size from the non‐focusing X‐ray spectrometer. Areas investigated range up to 0.9 inch2 (6 cm2)Imperial and metric equivalents, and measurements, throughout the paper are only approximate.
and a small individual grain 0.001 inch2 (1 mm2) has been detected. Examples of specimen compositional differences, as well as variations in concentration levels, are given.
Mass thickness measurement of pure element films by X‐ray fluorescence spectroscopy
Authors: Laguitton Daniel 
Published: May 2005

AbstractA precise and rapid method of measuring the mass thickness of pure element films using the LAMA Program to generate calibration curves by the fundamental parameters method is described. Only thick (‘bulk’) pure element standards are required thereby eliminating the necessity of preparing thin film standards. The accuracy is comparable to routine interferometry. A table giving the intensity ratios of the thin film to the corresponding thick standard is given for eighteen common elements and a thickness range of 500–100 000 Å, making it possible to apply the method without use of a computer.
X‐ray emission intensities of radionuclides in fallout from nuclear explosions
Authors: Sethi S. K. , Negi B. S. 
Published: May 2005

AbstractX‐ray emission intensities (number of X‐ray photons per 100 disintegrations) have been computed from gamma ray intensities, internal conversion, electron capture coefficients of the radionuclides and the fluorescence yields of the daughter products of various radionuclides normally observed in fallout from nuclear explosions. X‐ray spectrometry of these radionuclides would supplement the information, currently being obtained by radiochemical separation and subsequent radioactive counting, gamma ray spectrometry of fallout samples using NaI(T1) or Ge(Li) detectors and multichannel analysers. No results are so far available in the literature based on X‐ray spectrometry of radionuclides in fallout because of non‐availability or scanty data on X‐ray emission intensities of various radionuclides.
Precision of a commercial, wavelength‐dispersive X‐ray fluorescence spectrometer. A case study
Authors: Pupp Christian 
Published: May 2005

AbstractThe reproducibility of a sequential X‐ray spectrometer (Siemens SRS‐1) with a ten‐sample changer was investigated. It was found that variations due to electronic drift and goniometer reset were 0.015% and 0.02% (relative standard deviation), and those from voltage and current reset were about 0.3%, but that major variations were introduced by the ten‐sample changer. Non‐equivalence of its positions resulted in a variation of 0.31% and position reset with simultaneous spinning gave on of 0.47% with large fluctuations. It appears that use of a ten‐specimen changer of a certain design instead of a two‐specimen changer results in loss of precision in return for speed and convenience.
The calculation of mylar film absorption correction coefficients in X‐ray spectrochemical analysis of aqueous samples
Authors: Dick J. G. , Wan C. C. , Difruscia R. 
Published: May 2005

AbstractIn the analysis of specimens in aqueous media by the method of X‐ray fluorescence the measured intensity was found to be strongly affected by the mylar film used to cover the solution specimen cells.1,2 An increasingly critical absorbance level is observed with decreasing atomic number (increasing wavelength) of the element under examination. The investigation establishes correction coefficients relative to mylar film.
The X‐ray fluorescence analysis of ferronibium by a fusion method
Authors: Giles H. L. , Holmes G. M. 
Published: May 2005

AbstractAn X‐ray method has been developed for the routine determination of niobium, tantalum and residual elements inferrniobium. The sample is pre‐ooxidized and fuded in a misture of lanthanum oxide and lithium tetraborate. Calibration is by synthetic standards; molybdenum is added as internal standard for niobium, and corrections are applied for interferences on tantalum.
X‐ray fluorescence analysis of nibium‐germanium alloys
Authors: Vicente Victoria A. , Rasmussen Svend Erik 
Published: May 2005

AbstractA simple approach of the study of phase equilibria in niobium‐germanium alloys involves passing a floating molten zone along the alloy, cutting the resolidified rod into several, and analysing these sections by X‐ray fluoresce spectrometry and X‐ray diffraction. The relative net X‐ray fluorescent intensities were corrected for negative absorption effects, using a semi‐empirical procedure. The ‘effective wavelengh’ for exicitation of niobium and of germanium were deduced from experimental alpha‐coefficients.
The determination of the valency of manganese in minerals by X‐ray fluorescence spectroscopy
Authors: Urch D. S. , Wood P. R. 
Published: May 2005

AbstractThe Mn Kβ1,3, Kβ′ X‐ray emission peak profile varies in a characteristic way with the valency of manganese, Proviede that the ligand‐atom environment remains contant. Kβ′ becomes mopre prominent as the oxidation state is reduced. XRF nanalysis of geological sample can, therefore, be easily extended to include a determination of the predominant valence state of any manganese present.
Study of X‐ray L2 absorption edges of Gd, Dy, Ho and Er in metals and compunds
Authors: Angarwal B. K. , Agarwal B. R. K. 
Published: May 2005

AbstractThe positions and shapes of L2 X‐ray absorption edges of Gd, Dy, Ho and Er have been studied in metals and in oxides and chlorides, using a forty centimetre benbt mica crystal spectrograph. It has been found that the L2 edge shifts towards the high energy side in the compounds and that the chemical shift ΔE depends on the degree of covalency involved. The white line structure at the edge has been analysed in terms of transitions of L2 shell electron to optical nd (n≥5) states.
Application of direct peak analylsis to energy‐dispersive X‐ray fluoescence spectra
Authors: Nielson Kirk K. 
Published: May 2005

AbstractA modified covell method for direct peak analysis has been applied to energy‐dispersiv X‐ray flourescence spectra. The method is background independent and is well‐suited to computerized data reduction. It provides acceptable precision, minimizes errors from instrumental gain shift, and permits peak overlap correction. Peak overlap errors exhibit both positive and negative nodes as a function of peak separation distance, and are corrected using concentration ratios determined from thin, single‐element standards. Peak precisions and overlaps are evaluated as a function of window width to aid in width selection. Least‐square polynomial smoothing prior to peak analysis significantly improves peak area precisions without significantly affecting their accuracies.
The evaluation of the thallium acid phthalate crystal for X‐ray fluorescene spectrometry
Authors: Wybega F. T. 
Published: May 2005

AbstractThe Thallium Acid Phthalate (TIAP) analysing crystal is compared with KAP, RBAP and pentaerythritol (PE) crystal for the determination of light elements. Peak and background intensities are compared for various crystal‐collimator combinations. It is shown that TIAP is a very useful crystal to cover the range of elements F to Si.