|
|
|
X-ray fluorescence method for trace analysis and imaging
2000-08-01
X-ray fluorescence analysis has a long history as conventional bulk elemental analysis with medium sensitivity. However, with the use of synchrotron radiation x-ray fluorescence method has become a unique analytical technique which can provide tace elemental information with the spatial resolution. To obtain quantitative information of trace elemental distribution by using the x-ray fluorescence method, theoretical description of x-ray fluorescence yield is described. Moreover, methods and instruments for trace characterization with a scanning x-ray microprobe are described. (author)
2009-01-01
A new glancing incident X-ray fluorescence (GIXRF) spectrometer using parallel polycapillary X-ray lens has been developed. Integrated with a Zr filter and slits, a highly collimated and monochromatic X-ray beam has been achieved. This method eliminated the monochromator used in the conventional GIXRF method. Moreover the parallel X-ray lens increased the acceptance solid angle and hence increases intensities of the excitation spectrum. In this paper, this method has been applied in analysis of single crystal and film sample.
X-ray fluorescence holography (XFH) is a new structural analysis method of determining a 3D atomic arrangement around fluorescing atoms. We developed an XFH apparatus using advanced X-ray techniques and succeeded in obtaining high-quality hologram data. Furthermore, we introduced applications to the structural analysis of a thin film and the environment around dopants and, discussed the quantitative analysis of local lattice distortion. (author)
Filter-fluorescer measurement of low-voltage simulator x-ray energy spectra
1987-01-01
The filter-fluorescer method for measuring x-ray energy spectra is described. The method uses an eight-channel instrument to measure x-ray spectra at the Maxwell Laboratories' Modular Bremsstrahlung Source (MBS) and the Physics International Pulserad 737. Results agree reasonably well with calculated predictions of the spectra
First X-ray fluorescence excited Kossel diffraction in SEM
2008-01-01
Abstract. We present, for the first time, X-ray fluorescence excited Kossel patterns in the scanning electron microscope by way of a compact X-ray tube and a focusing polycapillary lens. Both the diffraction geometry in transmission and in back reflection can be carried out. The way is paved for the advantageous combination of micro-X-ray fluorescence analysis, the Laue method, and the X-ray fluorescence excited Kossel micro-diffraction with the high lateral resolution of the electron microscopy.
2007-01-01
A full-field X-ray fluorescence imaging microscope with a Wolter mirror was applied to the element mapping of alfalfa seeds. The X-ray fluorescence microscope was built at the Photon Factory BL3C2 (KEK). X-ray fluorescence images of several growing stages of the alfalfa seeds were obtained. X-ray fluorescence energy spectra were measured with either a solid state detector or a CCD photon counting method. The element distributions of iron and zinc which were included in the seeds were obtained using a photon counting method
2006-01-01
It is well known that Hg species cause high noxious effects on the health of living organisms even at very low levels (5 mug/L). Quantification of this element is an analytical challenge due to the peculiar physicochemical properties of all Hg species. The regulation of the maximal allowable Hg concentration led to search for sensitive methods for its determination. Total reflection X-ray fluorescence is a proved instrumental analytical tool for the determination of trace elements. In this work, the use of total reflection X-ray fluorescence for Hg quantification is investigated. However, experimental determination by total reflection X-ray fluorescence requires depositing a small volume of sample on the reflector and evaporation of the solvent until dryness to form a thin film. Because of volatilization of several Hg forms, a procedure to capture these ...
High-Definition X-Ray Fluorescence: Applications
2008-01-01
Energy dispersive X-ray fluorescence (EDXRF) is a well-established and powerful tool for nondestructive elemental analysis of virtually any material. It is widely used for environmental, industrial, pharmaceutical, forensic, and scientific research applications to measure the concentration of elemental constituents or contaminants. The fluorescing atoms can be excited by energetic electrons, ions, or photons. A particular EDXRF method, monochromatic microbeam X-ray fluorescence (MmuEDXRF), has proven to be remarkably powerful in measurement of trace element concentrations and distributions in a large variety of important medical, environmental, and industrial applications. When used with state-of-the-art doubly curved crystal (DCC) X-ray optics, this technique enables high-sensitivity, compact, low-power, safe, reliable, and rugged ...
High Definition X-Ray Fluorescence: Principles and Techniques
2008-01-01
Energy dispersive X-ray fluorescence (EDXRF) is a well-established and powerful tool for nondestructive elemental analysis of virtually any material. It is widely used for environmental, industrial, pharmaceutical, forensic, and scientific research applications to measure the concentration of elemental constituents or contaminants. The fluorescing atoms can be excited by energetic electrons, ions, or photons. A particular EDXRF method, monochromatic microfocus X-ray fluorescence (MmuEDXRF), has proven to be remarkably powerful in measurement of trace element concentrations and distributions in a large variety of important medical, environmental, and industrial applications. When used with state-of-the-art doubly curved crystal (DCC) X-ray optics, this technique enables high-sensitivity, compact, low-power, safe, reliable, and rugged ...
X-ray fluorescence analysis major elements in silicate minerals
1982-09-01
An automated wavelength-dispersive x-ray fluorescence spectrometer is operational for analysis of major elements in rocks and minerals. Procedures for trace-element analysis are being developed. Sample preparation methods and analytical techniques are similar to those commonly used elsewhere, but data reduction is conducted by the Fundamental Parameters program developed by Criss. Unlike empirically derived calibration curves, this data reduction method considers x-ray absorption and secondary fluorescence, which vary with differences in sample composition. X-ray intensities for each element from several standards are averaged to develop a theoretical standard for comparison with samples of unknown composition. Accurate data for samples with wide compositional ranges result from these data reduction and standardization techniques.
Archaeometrical studies using X-ray fluorescence methods
2010-01-01
Elemental analysis contributes to authentication (knowing the elemental composition and considering the information about the usual composition of the objects in different historical periods it can be established if the item is original or fake), provenance studies (minor and trace elements indicates ores origin and 'consequently' mines location), (relative) dating of archaeological objects (e.g. for painted items--the chemical recipes for pigments can offer information about the age of objects). The paper gives a general layout for the NIPNE Archaeometry Laboratory's applications using X-Ray Fluorescence (XRF), micro--Proton Induced X-Ray Emission (micro-PIXE), micro-Synchrotron Radiation Induced X-Ray Fluorescence (micro--SR-XRF) methods
1984-01-01
X-ray fluorescence spectrophotometry was employed to determined the metal content in a series of five transition element complexes (Mn, Ti, Zn, V). The results confirmed the molecular formulas of these complexes, already proposed on the basis of elemental microanalysis, solution condutimetry and other analytical methods.
X-ray fluorescence analysis by thin layer method
1981-01-01
Automated X-ray fluorescence analysis is described of liquid samples of ammoniacal carbonate extracts of Fe-Ni ores soaked in thin-layer papers. The concentration variations are shown of Fe, Ni, Co with the analytical line intensity. The results obtained are compared using atomic absorption spectroscopy and X-ray fluorescence analysis, the relative errors of reference determinations are shown, and the mean relative error is given for X-ray fluorescence analysis accuracy.
Ultra-soft x-ray absorption spectroscopy: A bulk and surface probe of materials
Direct comparisons between surface and bulk of diverse materials can be made by simultaneous electron yield (5 nm depth sensitivity) and fluorescence yield (200 nm) ultra soft x-ray absorption spectroscopy measurements utilizing a rapid sample interchange apparatus. For example the orientations of functional groups have been characterized at and near the surface of a series of model polymeric materials highlighting the chemical and molecular sensitivity of ultra soft x-ray absorption spectroscopy. In addition we discuss a bulk sensitive use of fluorescence yield to non destructively study a buried metal polymer interface. A second bulk sensitive example is the use of fluorescence yield oxygen K near edge x-ray spectroscopy as a method to determine the hole state density of high Tc materials.
Ultra-soft x-ray absorption spectroscopy: A bulk and surface probe of materials
1993-06-01
Direct comparisons between surface and bulk of diverse materials can be made by simultaneous electron yield (5 nm depth sensitivity) and fluorescence yield (200 nm) ultra soft x-ray absorption spectroscopy measurements utilizing a rapid sample interchange apparatus. For example the orientations of functional groups have been characterized at and near the surface of a series of model polymeric materials highlighting the chemical and molecular sensitivity of ultra soft x-ray absorption spectroscopy. In addition we discuss a bulk sensitive use of fluorescence yield to non destructively study a buried metal polymer interface. A second bulk sensitive example is the use of fluorescence yield oxygen K near edge x-ray spectroscopy as a method to determine the hole state density of high Tc materials.
2004-01-03
Synchrotron radiation (SR) methods have been utilized with increasing frequency over the past several years to study topics in actinide science, ranging from those of a fundamental nature to those that address a specifically-targeted technical need. In particular, the emergence of microspectroscopic and fluorescence-based techniques have permitted investigations of actinide materials at sources of soft x-ray SR. Spectroscopic techniques with fluorescence-based detection are useful for actinide investigations since they are sensitive to small amounts of material and the information sampling depth may be varied. These characteristics also serve to simplify both sample preparation and safety considerations. Examples of investigations using these fluorescence techniques will be described along with their results, as well as the prospects for future investigations utilizing these methodologies.
Ultra-soft x-ray absorption spectroscopy: A bulk and surface probe of materials
Direct comparisons between surface and bulk of diverse materials can be made by simultaneous electron yield (5 nm depth sensitivity) and fluorescence yield (200 nm) ultra soft x-ray absorption spectroscopy measurements utilizing a rapid sample interchange apparatus. For example the orientations of functional groups have been characterized at and near the surface of a series of model polymeric materials highlighting the chemical and molecular sensitivity of ultra soft x-ray absorption spectroscopy. In addition we discuss a bulk sensitive use of fluorescence yield to non destructively study a buried metal polymer interface. A second bulk sensitive example is the use of fluorescence yield oxygen K near edge x-ray spectroscopy as a method to determine the hole state density of high Tc materials.
Determination of fluorine by total reflection X-ray fluorescence spectrometry
2010-01-01
There is a growing interest in determination of low Z elements, i.e. carbon to phosphorus, in various samples. Total reflection X-ray fluorescence spectrometry (TXRF) has been already established as a suitable trace element analytical method with low sample demand and quite good quantification limits. Recently, the determinable element range was extended towards Z = 6 (carbon). In this study, the analytical performance of the total reflection X-ray fluorescence spectrometry for determination of fluorine was investigated applying a spectrometer equipped with Cr-anode X-ray tube, multilayer monochromator, vacuum chamber, and a silicon drift detector (SDD) with ultra thin window was used. The detection limit for fluorine was found to be 5 mg L-1 (equivalent to 10 ng absolute) in aqueous matrix. The linear range of the fluorine determination is between 15 and ...
Determination of fluorine by total reflection X-ray fluorescence spectrometry
2010-01-01
There is a growing interest in determination of low Z elements, i.e. carbon to phosphorus, in various samples. Total reflection X-ray fluorescence spectrometry (TXRF) has been already established as a suitable trace element analytical method with low sample demand and quite good quantification limits. Recently, the determinable element range was extended towards Z=6 (carbon). In this study, the analytical performance of the total reflection X-ray fluorescence spectrometry for determination of fluorine was investigated applying a spectrometer equipped with Cr-anode X-ray tube, multilayer monochromator, vacuum chamber, and a silicon drift detector (SDD) with ultra thin window was used. The detection limit for fluorine was found to be 5mgL^-^1 (equivalent to 10ng absolute) in aqueous matrix. ...
Method for improving the accuracy of continuous X-ray fluorescence analysis of iron ore mixtures
2010-01-01
The dependence of the intensity of X-ray fluorescence on the distance between the spectrometer and the test sample is studied. Changes in the intensity of primary X-radiation, absorption of X-rays by the air, and surface area of the analyzed material are calculated. An efficient method is proposed for improving the accuracy of continuous X-ray fluorescence analysis of iron ore mixtures on the conveyor belt through the exclusion of incorrect results by the dead time of the detection unit. The proposed method is universal and can be used for various loose materials.
2009-01-01
Of particular interest when studying the effects of deicing solutions on concrete is the depth of penetration of ions from deicing salts. To determine the limits of positive ion infiltration, a method based on milli X-ray fluorescence (mXRF) has been developed. This method combines traditional energy dispersive spectrometry (EDS) with stage movement X-ray mapping to analyze comparatively large areas of concrete. The result is the ability to determine the depth of ion infiltration over a distance of tens of millimeters. The technique also requires minimal preparation of the sample, and due to the nature of the X-ray beam, concrete samples do not have to be coated to reduce charging. This paper describes in detail the method of mXRF with X-ray spectrum imaging (XSI) for concrete applications...
2008-01-01
Unlike traditional outside-source holography, X-ray fluorescence holography is carded out with fluorescent atoms in a sample as source light for holographic imaging. With the method, three-dimensional arrangement of atoms into crystals can be observed obviously. However, just like traditional outside-source holography, X-ray fluorescence holography suffers from the inherent twin-image problem, too. With a 27-Fe-atoms cubic lattice as model, we discuss in this paper influence of the photon energy of incident source in removing twin images in reconstructed atomic images by numerical simulation and reconstruction with two-energy X-ray fluorescence holography. The results indicate that incident X-rays of nearer energies have better effect of removing twin images. In the detector of X-ray holography, minimum difference of the two incident energies depends on ...
A method of generating k-fluorescence x-rays
1992-04-01
For radiation protection purposes of k-fluorescence x-rays are useful for determining the energy response of instruments and dosimeters because they are nearly monoenergetic. the International Organization for Standardization (ISO) has specified the x-ray energies and radiator and filter materials for the production of such x-rays. There are two techniques useful for producing x-rays at approximately 17 and 59 keV; these techniques produce a situation that approximates the x-ray and gamma ray emissions of plutonium and americium isotopes. The Department of Energy Laboratory Accreditation Program (DOELAP) performance-testing standard for personnel dosimeters incorporates these k-fluorescence techniques. The Radiation Calibrations Facility at the Pacific Northwest Laboratory (PNL) has produced k-fluorescence x-rays for many years. Over the years, we have worked at improving this type of radiation for our performance-testing programs. This report describes the present geometry for the generation of k-fluorescence x-rays, a geometry proven more efficient in our facility. The exposure rate has increased and the beam uniformity has improved. Details of the geometry will be discussed.
A method of generating k-fluorescence x-rays
1992-04-01
For radiation protection purposes of k-fluorescence x-rays are useful for determining the energy response of instruments and dosimeters because they are nearly monoenergetic. the International Organization for Standardization (ISO) has specified the x-ray energies and radiator and filter materials for the production of such x-rays. There are two techniques useful for producing x-rays at approximately 17 and 59 keV; these techniques produce a situation that approximates the x-ray and gamma ray emissions of plutonium and americium isotopes. The Department of Energy Laboratory Accreditation Program (DOELAP) performance-testing standard for personnel dosimeters incorporates these k-fluorescence techniques. The Radiation Calibrations Facility at the Pacific Northwest Laboratory (PNL) has produced k-fluorescence x-rays for many years. Over the years, we have worked at improving this type of radiation for our performance-testing programs. This report describes the present geometry for the generation of k-fluorescence x-rays, a geometry proven more efficient in our facility. The exposure rate has increased and the beam uniformity has improved. Details of the geometry will be discussed.
Continuous X-ray fluorescence analysis of iron ore mixtures in the production of agglomerate
2010-01-01
A system is developed for the continuous control of the chemical composition of iron ore mixtures (IOMs) by X-ray fluorescence analysis (XRF) directly on the conveyor belt. The system was found to be efficient under the conditions of mining and smelting production at the Magnitogorsk Metallurgical Combine. The proposed XRF method does not require sampling; provides the required accuracy; and offers advantages over other methods of analysis in terms of rapidity, cost, and productivity. The introduction of the system with an energy dispersive X-ray fluorescence spectrometer has improved the reliability of the operative control of the chemical composition of IOMs.
2007-01-01
A full-field x-ray fluorescence imaging microscope using a Wolter mirror was constructed at Photon Factory BL3C2. White x rays from a bending magnet were used to excite x-ray fluorescence and to enhance the x-ray fluorescence intensity. A photon-counting method using a charge-coupled device was applied to obtain an x-ray fluorescence spectrum at the image plane. The spatial distributions of some specific atoms such as Fe and Zn were obtained from photon-counting calculations. An energy resolution of 220 eV at the Fe Kalpha line was obtained from the x-ray fluorescence spectrum by the photon-counting method. The newly developed three-dimensional element mappings of the specific atoms were accomplished by the photon-counting method and a reconstruction technique using computed tomography
Radiochemical methods in analysis
1975-01-01
This book surveys all aspects of radioactivity as applied to activation analysis, radio release methods, isotope dilution analysis, absorption and back scattering methods, x-ray fluorescence, and Moessbauer spectroscopy. Separate abstracts were prepared for each of the eleven chapters. Each chapter includes an extensive bibliography. (DDA)
Quantitative X ray analysis system. User's manual and guide to X ray fluorescence technique
2009-01-01
This guide covers trimmed and re-arranged version 3.6 of the Quantitative X ray Analysis System (QXAS) software package that includes the most frequently used methods of quantitative analysis. QXAS is a comprehensive quantitative analysis package that has been developed by the IAEA through research and technical contracts. Additional development has also been carried out in the IAEA Laboratories in Seibersdorf where QXAS was extensively tested. New in this version of the manual are the descriptions of the Voigt-profile peak fitting, the backscatter fundamental parameters' and emission-transmission methods of chemical composition analysis, an expanded chapter on the X ray fluorescence physics, and completely revised and increased number of practical examples of utilization of the QXAS software package. The analytical data accompanying this manual were collected ...
X-ray methods for the chemical characterization of atmospheric aerosols
1981-05-01
The development and use of several x-ray methods for the chemical characterization of atmospherical aerosol particulate samples are described. These methods are based on the emission, absorption, and scattering of x-ray photons with emphasis on the optimization for the non-destructive analysis of dilute specimens. Techniques discussed include photon induced energy dispersive x-ray fluorescence, extended x-ray absorption fine structure spectroscopy using synchrotron radiation and high-rate x-ray powder diffractometry using a position-sensitive gas proportional counter. These x-ray analysis methods were applied to the measurement of the chemical compositions of size-segregated aerosol particulate samples obtained with dichotomous samplers. The advantages of the various methods for use in such measurements are described and results are presented. In many cases, the complementary nature of the analytical information obtained from the various measurements is an important factor in the characterization of the sample. For example, the multiple elemental analyses obtained from x-ray fluorescence can be used as a cross check on the major compounds observed by powder diffraction.
X-ray tubes for specific test procedures. Roentgenroehren fuer spezielle Pruefverfahren
1978-01-01
X-ray materials testing is carried out in highly different objects and according to highly different methods. Some of these objects are pipelines several kilometers long, mass-production goods like tyres, and dust particles. The methods used ragne irradiation tests to X-ray fine structure investigations and fluorescence analysis. These many tasks of course, require also highly different radiation sources. Present methods to produce X-ray tubes of unconventional shape at a reasonable cost are described in the article. (orig./RW)
1995-01-01
A correction method for the overlapping of the fluorescent X-ray lines is described for the simultaneous determination of the elements in geological samples using a wavelength dispersive X-ray fluorescence spectrometer. The method is based on the constant relation of the relative intensity between Kalpha and Kbeta1 lines for the influenced element. Geological standard reference materials were employed as a standard sample for the estimation of Kalpha/Kbeta1 ratio. The proposed method was applied to the determination of arsenic in Pond Sediment (NIES No. 2) and Estuarine Sediment (NBS SRM1646), and the results were in good agreement with the recommended values. (author)
Development of total uranium analytical method by L x-ray fluorescence
1996-09-18
This paper describes development of an L x-ray fluorescence technique to perform total uranium analysis using an internal excitation source which is added directly to the sample. The method has been demonstrated with synthetic U samples in the limited concentration range of 1g/l to 15g/l, and provides the advantages of simplicity, involving no mechanical parts which would normally be found in an external excitation source. Total uranium is determined by counting L x-rays fluoresced by a microCurie level spike of Cd-109 added directly to the sample and without shielding the excitation source from the detector. A method for correction of sample self-absorption is included in the analysis.
Development of total uranium analytical method by L X-ray fluorescence
1998-02-01
This paper describes development of an L X-ray fluorescence technique to perform total uranium analysis using an internal excitation source which is added directly to the sample. The method has been demonstrated with synthetic U samples in the limited concentration range 1-15 g/l, and provides the advantage of simplicity, involving no mechanical parts which would normally be found in an external excitation source. Total uranium is determined by counting L X-rays fluoresced by a microCurie level spike of {sup 109}Cd added directly to the sample and without shielding the excitation source from the detector. A method for correction of sample self-absorption is included in the analysis. (orig.). 5 refs.
X-ray specular reflection and fluorescence study of nano-films
2001-01-01
The techniques that combine the advantages of high-resolution structure sensitive x-ray methods with spectroscopic selectivity of data obtained are shown to be extremely promising for characterization of organic and inorganic nano films and nano structures. Fluorescence yield angular dependences exited by complicated evanescent wave / x-ray standing wave pattern at total reflection and glancing incidence can be used to detect structure position of different ions in organic systems and alien interfacial layers in inorganic multilayers., to get information about interdiffusion at the interfaces of Langmuir- Blodgett (L-B) films and artificial inorganic - x-ray mirrors. To study ion permeation through L-B nano structures - models of biomembrans. To obtain nano - film thickness and density. To get precisely the parameters of small d-space multilayer mirrors, ets
A method for analyzing geochemical specimens by energy dispersive x-ray fluorescence is described. The fact is used that at any given x-ray energy between adjacent major element absorption edges, both the reciprocal of the specimen mass absorption coefficient and the spectral background intensity vary linearly with the intensity of the Compton scattered excitation radiation. Hence, Compton scattered excitation radiation serves a dual role: as an internal standard and as a measure of spectral background intensity. Several pure compounds, for which the x-ray cross sections vary over a wide range, are used to develop individual x-ray line spectral background curves. Standardization is achieved utilizing geochemical reference standards. Accuracies typically obtained are 5% or better using 20-in analysis periods.
1977-01-01
A method for analyzing geochemical specimens by energy dispersive x-ray fluorescence is described. The fact is used that at any given x-ray energy between adjacent major element absorption edges, both the reciprocal of the specimen mass absorption coefficient and the spectral background intensity vary linearly with the intensity of the Compton scattered excitation radiation. Hence, Compton scattered excitation radiation serves a dual role: as an internal standard and as a measure of spectral background intensity. Several pure compounds, for which the x-ray cross sections vary over a wide range, are used to develop individual x-ray line spectral background curves. Standardization is achieved utilizing geochemical reference standards. Accuracies typically obtained are 5% or better using 20-in analysis periods.
1991-01-01
Trace metals such as vanadium, nickel, and iron in fluid catalytic cracking feedstocks deposit on the catalyst and adversely affect catalyst activity and product yields. Vanadium compounds can also cause damage to furnace linings and corrosion of boiler tubes or gas turbine blades. A rapid and sensitive analytical method is need to detect these metals in feedstocks, products, and residual. In this paper such a method using energy dispersive X-ray fluorescence (EDXRF) spectrometry for determination of vanadium, nickel, and iron in petroleum and petroleum residua is described. In order to eliminate matrix effects, samples containing an internal standard (cobalt) were decomposed by heating with concentrated sulfuric acid and the resulting carbonaceous residua were ashed. X-ray fluorescent spectral intensities of V, Ni, Fe, and Co were measured using established ...
2008-01-01
Total reflection X-ray fluorescence (TXRF) is a very promising method for the direct, quick and reliable multi-elemental quantification of trace elements in protein samples. With the introduction of an internal standard consisting of two reference elements, scandium and gallium, a wide range of proteins can be analyzed, regardless of their salt content, buffer composition, additives and amino acid composition. This strategy also enables quantification of matrix effects. Two potential issues associated with drying have been considered in this study: (1) Formation of heterogeneous residues of varying thickness and/or density. And (2) separation of the internal standard and protein during drying (which has to be prevented to allow accurate quantification). These issues were investigated by microbeam X-ray fluorescence (muXRF) with special emphasis on ...
2008-01-01
Many studies have identified an important number of toxic elements along with organic carcinogen molecules and radioactive isotopes in tobacco. In this work we have analyzed by Total Reflection X-Ray Fluorescence 9 brands of cigarettes being manufactured and distributed in the Mexican market. Two National Institute of Standards and Technology standards and a blank were equally treated at the same time. Results show the presence of some toxic elements such as Pb and Ni. These results are compared with available data for some foreign brands, while their implications for health are discussed. It can be confirmed that the Total Reflection X-Ray Fluorescence method provides precise (reproducible) and accuracy (trueness) data for 15 elements concentration in tobacco samples
2009-01-01
In clinical service laboratories, one of the most common analytical tasks with regard to inorganic traces is the determination of the nutrition-relevant elements Fe, Cu, Zn, and Se. Because of the high numbers of samples and the commercial character of these analyses, a time-consuming sample preparation must be avoided. In this presentation, the results of total reflection X-ray fluorescence measurements with a low-power system and different sample preparation procedures are compared with those derived from analysis with common methods like Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The results of these investigations indicate that the optimal total reflection X-ray fluorescence analysis of the nutrition-relevant elements Fe, Cu, Zn, and...
X-ray fluorescence in IAEA Member States: Austria. Recent results of the ATI X ray group with SR-XRF
2007-01-01
Total Reflection X ray Fluorescence (TXRF) technique is a special method of energy dispersive X ray fluorescence analysis extending the analytical performance of XRF in the trace and ultra trace element range. It is an internationally accepted and worldwide-applied analytical method with detection limits in the pg range using X ray tubes as excitation source. The obtained detection limits depend strongly on the excitation source and photon flux on the sample. To improve the detection limits, the use of new excitation sources offering more photon flux is required. Using rotating anode tubes, the detection limits obtained are in the some 100 fg range. Synchrotron radiation turned out to be excellent suitable for being used as excitation source in TXRF and our working group was one of the pilot teams to reach detection limits in the fg range. The applicability of TXRF ranges from any ...
X-ray Fluorescence Spectroscopy Study of Coating Thickness and Base Metal Composition
For electrical, electronic, and electromechanical (EEE) parts to be approved for space use, they must be able to meet safety standards approved by NASA. A fast, reliable, and precise method is needed to make sure ...
Subgroup report on hard x-ray microprobes
1994-09-01
The increasing availability of synchrotron x-ray sources has stimulated the development of advanced hard x-ray (E{>=}5 keV) microprobes. New x-ray optics have been demonstrated which show promise for achieving intense submicron hard x-ray probes. These probes will be used for extraordinary elemental detection by x-ray fluorescence/absorption and for microdiffraction to identify phase and strain. The inherent elemental and crystallographic sensitivity of an x-ray microprobe and its inherently nondestructive and penetrating nature makes the development of an advanced hard x-ray microprobe an important national goal. In this workshop state-of-the-art hard x-ray microprobe optics were described and future directions were discussed. Gene Ice, Oak Ridge National Laboratory (ORNL), presented an overview of the current status of hard x-ray microprobe optics and described the use of crystal spectrometers to improve minimum detectable limits in fluorescent microprobe experiments. Al Thompson, Lawrence Berkeley Laboratory (LBL), described work at the Center for X-ray Optics to develop a hard x-ray microprobe based on Kirkpatrick-Baez (KB) optics. Al Thompson also showed the results of some experimental measurements with their KB optics. Malcolm Howells presented a method for bending elliptical mirrors and Troy Barbee commented on the use of graded d spacings to achieve highest efficiency in KB multilayer microfocusing. Richard Bionta, Lawrence Livermore National Laboratory (LLNL), described the development of the first hard x-ray zone plates and future promise of so called {open_quotes}jelly roll{close_quotes} or sputter slice zone plates. Wenbing Yun, Argonne National Laboratory (ANL), described characterization of jelly roll and lithographically produced zone plates and described the application of zone plates to focus extremely narrow bandwidths by nuclear resonance. This report summarizes the presentations of the workshop subgroup on hard x-ray microprobes.
Holographic analysis of diffraction structure factors
2002-02-05
We combine the theory of inside-source/inside-detector x-ray fluorescence holography and Kossel lines/x ray standing waves to directly obtain the phases of the diffraction structure factors. The influence of Kossel lines and standing waves on holography is also discussed. We demonstrate the phase determination method on experimental data obtaining the sign of the real part of the structure factor for several reciprocal lattice vectors of a vanadium crystal.
Radioisotope induced X-ray fluorescence analysis of cereal grains and flour
1983-01-01
Radioisotope induced X-ray fluorescence analysis is a rather simple and convenient method for investigating ashed plant materials. In other to reduce matrix effects, thin samples (2 mg/cm/sup 2/) are analyzed to obtain a reasonable compromise between maximum sensitivity and the lowest possible absorption effects. Concentrations are determined by standard addition method. A precision of 6-8% can be achieved. As an application, analytical results are given for whole grains of several sorts of wheat.
Determination of Fe, Zn and Pb in Zn-Pb ores by energy-dispersive X-ray fluorescence method
1984-03-01
Energy-dispersive X-ray fluorescence method for the determination of iron (3.5-26% of Fe), zinc (0.5-9% of Zn) and lead (0.05-5% of Pb) in zinc-lead ores containing arsenic has been worked out. In order to eliminate the inter-element effects, intensity correction equation has been proposed. The relative standard deviation of the determination varies from 3.6 to 9.2% depending on the element. 2 refs.
2009-01-01
Quantitative analysis using the fundamental parameter method is often employed for X-ray fluorescence analysis. When the major component of the sample is resin, it was usually considered to be CH2O and was quantified as a balance compound without actual measurements. This approach was frequently used due to the difficulty in measuring the carbon, hydrogen, and oxygen in resin. However, this method has a disadvantage to yield unstable quantitative analysis results for pellets and other irregularly shaped samples. Therefore we avoid using this balance compound approach, and investigate methods to quantify the major component of resin, CH2O, using the Rh Kalpha Compton scattering. The Rh Kalpha Compton scattering is generated by a rhodium target X-ray tube scattered by the sample. The present method is used for ...
Student X-Ray Fluorescence Experiments
Describes the experimental arrangement for x-ray analysis of samples which involves the following: the radioisotopic x-ray disk source; a student-built fluorescence chamber; the energy dispersive x-ray detector, linear amplifier and bias supply; and a multichannel
Overview and perspective of materials characterization by using synchrotron radiation
2009-01-01
A peculiarity of techniques and the methods of synchrotron radiation are explained. It consists of five sections such as introduction, synchrotron radiation, interaction between X-ray and materials, analytical methods of materials using synchrotron radiation and perspective and problems. The second section described the principles of synchrotron orbit radiation, synchrotron light source, the main formulae and schematic drawing of undulator, and the synchrotron radiation facilities in Japan. The third section explained behavior of X-ray in materials, absorption, reflection, refraction and scattering of X-ray. The fourth section stated many analytical methods of materials. The surface diffractometer, powder diffractometer, high-energy X-ray diffraction, core-electron absorption spectroscopy, micro-beam diffraction, X-ray fluorescence, X-ray ...
NEW CORRECTION PROCEDURE FOR X-RAY SPECTROSCOPIC FLUORESCENCE DATA: SIMULATIONS AND EXPERIMENT.
X-ray fluorescence spectroscopy is a widely used method for determining the electronic configuration and local structure of dilute species with high sensitivity. In the dilute limit, and for thin films, the X-ray fluorescence signal is directly proportional to the atomic sub-shell absorption coefficient. However, for concentrated samples, the well-documented self-absorption effect often leads to the severe suppression of XANES (X-ray Absorption Near-Edge Structure) and EXAFS (Extended X-ray Absorption Fine-Structure) amplitudes. Thus to recover the real value of the sub-shell absorption coefficient, it is important to apply correction procedures to the measured fluorescence spectra. In this paper, we describe a new straightforward method to correct for self-absorption effects (the difference in the measured fluorescence signal compared to that of the true sub-shell photoabsorption coefficient) in XANES and EXAFS fluorescence measurements. Using a variety of sample and detector configurations, this method is used to extract the sub-shell absorption coefficient on elemental nickel and thick single-crystals of Gd{sub 3}Ga{sub 5}O{sub 12} and LaAlO{sub 3}.
NEW CORRECTION PROCEDURE FOR X-RAY SPECTROSCOPIC FLUORESCENCE DATA: SIMULATIONS AND EXPERIMENT.
2004-08-02
X-ray fluorescence spectroscopy is a widely used method for determining the electronic configuration and local structure of dilute species with high sensitivity. In the dilute limit, and for thin films, the X-ray fluorescence signal is directly proportional to the atomic sub-shell absorption coefficient. However, for concentrated samples, the well-documented self-absorption effect often leads to the severe suppression of XANES (X-ray Absorption Near-Edge Structure) and EXAFS (Extended X-ray Absorption Fine-Structure) amplitudes. Thus to recover the real value of the sub-shell absorption coefficient, it is important to apply correction procedures to the measured fluorescence spectra. In this paper, we describe a new straightforward method to correct for self-absorption effects (the difference in the measured fluorescence signal compared to that of the true sub-shell photoabsorption coefficient) in XANES and EXAFS fluorescence measurements. Using a variety of sample and detector configurations, this method is used to extract the sub-shell absorption coefficient on elemental nickel and thick single-crystals of Gd{sub 3}Ga{sub 5}O{sub 12} and LaAlO{sub 3}.
New Correction Procedure For X-ray Spectroscopic Fluorescence Data: Simulations and Experiment
2005-01-01
X-ray fluorescence spectroscopy is a widely used method for determining the electronic configuration and local structure of dilute species with high sensitivity. In the dilute limit, and for thin films, the X-ray fluorescence signal is directly proportional to the atomic sub-shell absorption coefficient. However, for concentrated samples, the well-documented self-absorption effect often leads to the severe suppression of XANES (X-ray Absorption Near-Edge Structure) and EXAFS (Extended X-ray Absorption Fine-Structure) amplitudes. Thus to recover the real value of the sub-shell absorption coefficient, it is important to apply correction procedures to the measured fluorescence spectra. In this paper, we describe a new straightforward method to correct for self-absorption effects (the difference in the measured fluorescence signal compared to that of the true sub-shell photoabsorption coefficient) in XANES and EXAFS fluorescence measurements. Using a variety of sample and detector configurations, this method is used to extract the sub-shell absorption coefficient on elemental nickel and thick single-crystals of Gd{sub 3}Ga{sub 5}O{sub 12} and LaAlO{sub 3}.
Characterization of geosynthetic clay liner bentonite using micro-analytical methods
2010-01-01
In barrier design, familiarity of the structure and composition of the soil material at the micron scale is necessary for delineating the retention mechanisms of introduced metals, such as the formation of new mineral phases. In this study, the mineralogical and chemical makeup of the bentonite from a geosynthetic clay liner (GCL) was extensively characterized using a combination of conventional benchtop X-ray diffraction (XRD) and micro X-ray diffraction (mXRD) with synchrotron-generated micro X-ray fluorescence (mXRF) elemental mapping and mXRD (S-mXRD). These methods allow for the non-destructive, in situ investigation of a sample, with mm spatial resolution. Synchrotron-based hard X-ray microprobes are specifically advantageous to the study of trace metals due to higher spatial resolut...
The application of EDXRF technology for prospecting of metal mine
2008-01-01
Introduce technology and the application of portable high-precision X-ray fluorescence analyzer for prospecting of metal mine in Jingxian of Anhui province. Discuss the principle of EDXRF and influence factors while prospecting on live mainly: base matrix effect, moisture effect and roughness effect, etc. The component and element's contents of samples can be measured directly by portable high-precision X-ray fluorescence analyzer. The detection limits range from 100 to 200 mg/kg, and the precision is 2%-10%. It comes to a conclusion that the EDXRF technology is a fast portable economical and efficient field prospecting method. (authors)
Simultaneous analysis of gaseous and particle sulfur in the atmosphere by fluorescent x-ray analysis
1974-11-01
Sulfur trioxide was analyzed by the usual method. A small percentage of sulfur trioxide from sulfur dioxide was absorbed by floating particles of sulfuric acid mist and could not be analyzed by the usual alkali wet filter. Instead, contaminated air was passed through a membrane filter and SO/sub 3/ particles were caught on the filter. The SO/sub 2/ in penetrating gas was absorbed by an alkali wet filter. A fluorescent X-ray analysis was done simultaneously on the SO/sub 2/ gas and SO/sub 3/ particles.
Role of XRF in the certification of standard reference materials (SRMS)
2008-01-01
This paper presents the results for the determination of eleven elements in a sample of environmental origin(IAEA SL-1) which was floated for a proficiency test exercise by IAEA for the laboratories using x-ray fluorescence technique. Analysis was performed on a wavelength dispersive x-ray fluorescence spectrometer using lithium fluoride (LiF200) and pentaerythritol (PET) crystals in combination with sealed proportional counter (Kr) for the estimation of K, Ca, Fe, Ti, Mn, Ni, Cr, Zn, Sr and Ba. Accuracy of the method for most of the elements was found within +- 5%. (author)
Radioactive ore analysis by optimized radioisotope X-ray fluorescence technique
1981-01-01
A method for analyzing U and Th in radioactive ores by radioisotope excited X-ray fluorescence is described. For the proposed analysis, the theoretical and experimental factors that affect the sensitivity of the radioisotope XRF technique were investigated. Minimum detection limits of 13 ppm and 108 ppm can be achieved for U and Th, respectively, with a total counting time of 1000 s on a powdered ore sample. Results obtained in the analyses of radioactive ores from Turkey and BL-5 candidate reference uranium ores from CANMET (Canada Centre for Mineral and Energy Technology) are reported.
1995-01-01
A methodology for quantitative analysis of geological, biological and environmental samples with a high fraction of light elements (atomic number less than 13), using energy dispersive X-ray fluorescence technique with radioisotopic excitation, is proposed. The proposed procedure is based on the method of Fundamental Parameters for analytical elements (
2010-01-01
A deposition system capable of delivering picoliter quantities of solution in programmable arrays was investigated as a method for sample preparation for total reflection X-ray fluorescence (TXRF) spectroscopy. Arrays of trace metals in solution were deposited on Si wafers. The array deposits provide a capability of depositing closely spaced (100mm or less), typically 5-20mm diameter droplets in an area that can be matched to the analysis spot of the TXRF detector. The dried depositions were physically characterized and the effect of deposition type and matrix on the TXRF signal was investigated.
1982-05-01
Precipitation with combined dibenzylammonium dibenzyldithiocarbamate and sodium dibenzyldithiocarbamate at pH 5.0 can be used to separate 22 trace elements from water. Membrane filtration of the precipitate yielded a thin sample, suitable for analysis by energy dispersive X-ray fluorescence spectrometry. Alkalis, alkaline earths, lanthanides, and halides were not precipitated, permitting a clean separation of trace elements from the macro constituents of drinking water and drinking water supplies. Methods are given for preparation of reagents of higher purity than previously described.
2008-01-01
A laboratory method is proposed for the determination of the emission spectrum of an X-ray tube of a wavelength-scattering series X-ray fluorescence spectrometer. The developed approach is based on the description of distortions by the spectrometer units and an inverse mathematical transformation of the wavelength distribution of the intensity of the primary radiation scattered by a special auxiliary sample. The developed algorithm is convenient for refining the spectrum of an X-ray tube with its physical deterioration during operation
Determination of K, Ca, Fe and Ni in Leptinotarsa decemlineata (Say) by EDXRF spectroscopy
2006-01-15
The metal content of Colorado potato beetles elytra in Turkey was determined using the energy dispersive X-ray fluorescence method. A radioisotope excited X-ray fluorescence analysis using the method of standard addition is applied for the elemental analysis of Colorado potato beetles elytra. An annular 50mCi{sup 241}Am radioactive source and an annular 50mCi{sup 55}Fe radioactive source were used for excitation of characteristic K X-rays. An Si(Li) detector which has a 147eV full-width at half-maximum for 5.9keV photons was used for intensity measurements. The procedure of sample preparation and the results of analysis were presented.
2009-07-15
X-ray fluorescence (XRF) and total-reflection X-ray fluorescence (TXRF) techniques suited well for a multi-element determination of K, Ca, Mn, Fe, Cu, Zn, Rb, and Sr in some Syrian medicinal plant species. The accuracy and the precision of both techniques were verified by analyzing the Standard Reference Materials (SRM) peach-1547 and apple leaves-1515. A good agreement between the measured concentrations of the previously mentioned elements and the certified values were obtained with errors less than 10.7% for TXRF and 15.8% for XRF. The determination of Br was acceptable only by XRF with an error less than 24%. Furthermore, the XRF method showed a very good applicability for the determination of K, Ca, Mn, Fe, Cu, Zn, Rb, Sr, and Br in infusions of different Syrian medicinal plant species, namely anise (Anisum vulgare), licorice root (Glycyrrhiza glabra), and white wormwood (Artemisia herba-alba)
2009-01-01
X-ray fluorescence (XRF) and total-reflection X-ray fluorescence (TXRF) techniques suited well for a multi-element determination of K, Ca, Mn, Fe, Cu, Zn, Rb, and Sr in some Syrian medicinal plant species. The accuracy and the precision of both techniques were verified by analyzing the Standard Reference Materials (SRM) peach-1547 and apple leaves-1515. A good agreement between the measured concentrations of the previously mentioned elements and the certified values were obtained with errors less than 10.7% for TXRF and 15.8% for XRF. The determination of Br was acceptable only by XRF with an error less than 24%. Furthermore, the XRF method showed a very good applicability for the determination of K, Ca, Mn, Fe, Cu, Zn, Rb, Sr, and Br in infusions of different Syrian medicinal plant species, namely anise (Anisum vulgare), licorice root (Glycyrrhiza glabra), and white ...
Modern methods for trace element analysis
1978-01-01
Various analytical methods for the determination of trace elements are discussed with particular emphasis on determination of trace elements in the environment. The methods covered in detail are fluorometry, emission spectroscopy, flame atomic absorption spectrometry, flameless atomic fluorescence spectrometry, x-ray fluorescence spectrometry, and activation analysis. Much additional information is included in the appendices. (BLM)
Experimental evidence for secondary excitation in X-ray photoelectron spectrometry
2003-01-01
Theoretical considerations of X-ray fluorescence analysis show that secondary excitation of characteristic radiations can contribute up to 30% to measured signals. A similar theoretical approach describes the generation of X-ray photoelectron spectra. The remarkable difference between these two X-ray analytical methods is that for X-ray photoelectron spectroscopy signals from primary and secondary excitation can be distinguished. Thus, X-ray photoelectron spectrometry offers a possibility to check the theoretical concepts of quantitative X-ray analysis. This paper deals with the theory of primary excitation of X-ray photoelectron spectra of thin Au films on Mg substrates by AlKalpha from tube X-rays and of secondary excitation by MgKalpha from the substrate. Experimental results confirm the theoretical approach. Furthermore, ...
Quantitative X-ray fluorescence analysis Quantitative Roentgenfluoreszenzenanalyse
1997-01-01
Quantitative X-ray Fluorescence Analysis (XRF) is investigated as a nondestructive (nonconsumptive) analytical method for determination of elemental concentrations in homogenous specimen. The program package has been developed to calculate countrates of several XRF lines for given concentrations in an alloy by simulating each component of a typical energy dispersive XRF spectrometer. Three different approaches of modeling the spectrum of a X-ray tube are implemented. Primary and secondary excitations are taken into account to describe the fluorescence process. A module describing the sensitivity of energy dispersive Sili detectors is added together with routines giving the attenuation of primary and fluorescence radiation in air an be windows. The above mentioned simulation is based on fundamental parameter data-bases and does not require measurements of ...
2008-01-01
The determination of trace element mass concentrations in ambient air with a time resolution higher than one day represents an urgent need in atmospheric research. It involves the application of a specific technique both for the aerosol sampling and the subsequent analysis of the collected particles. Beside the intrinsic sensitivity of the analytical method, the sampling interval and thus the quantity of collected material that is available for subsequent analysis is a major factor driving the overall trace element detection power. This is demonstrated for synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) of aerosol samples collected with a rotating drum impactor (RDI) in hourly intervals and three particle size ranges. The total aerosol mass on the 1-h samples is in the range of 10 mug. An experimental detection of the nanogram amounts of trace ...
2008-01-01
The determination of trace element mass concentrations in ambient air with a time resolution higher than one day represents an urgent need in atmospheric research. It involves the application of a specific technique both for the aerosol sampling and the subsequent analysis of the collected particles. Beside the intrinsic sensitivity of the analytical method, the sampling interval and thus the quantity of collected material that is available for subsequent analysis is a major factor driving the overall trace element detection power. This is demonstrated for synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) of aerosol samples collected with a rotating drum impactor (RDI) in hourly intervals and three particle size ranges. The total aerosol mass on the 1-h samples is in the range...
The Sherman equations as a nonlinear Perron eigenvalue problem
2010-01-01
When a chemical sample composed of N elements is analyzed using sequential selective excitation by a tunable polyenergetic X-ray beam and selective measurement of the characteristic X-rays, the production of secondary fluorescence does not interfere with the measurements. This experimental situation leads to a particular case of the Sherman equations which can be written as a set of non-linear equations. The same kind of equations are also obtained when we excite a chemical sample with a polyenergetic X-ray beam and neglect the production of secondary fluorescence. This set of equations can be regarded as a non-linear eigenvalue problem. A non-linear extension of the Perron Frobenious theorem ensures that there is one and only one physically acceptable solution, and also leads to a method ...
2008-01-01
Total reflection X-ray Fluorescence (TXRF) analysis in combination with X-ray Absorption Near Edge Structure (XANES) analysis is a powerful method to perform chemical speciation studies at trace element levels. However, when measuring samples with higher concentrations and in particular standards, damping of the oscillations is observed. In this study the influence of self-absorption effects on TXRF-XANES measurements was investigated by comparing measurements with theoretical calculations. As(V) standard solutions were prepared at various concentrations and dried on flat substrates. The measurements showed a correlation between the damping of the oscillations and the As mass deposited. A Monte-Carlo simulation was developed using data of the samples shapes obtained from confocal white light microscopy. The results showed good agreement with the ...
Micro X-ray diffraction and fluorescence tomography for the study of multilayered automotive paints
2010-01-01
Combined microscopic X-ray fluorescence/microscopic X-ray diffraction (-XRF/-XRD) tomography is a recently developed method that allows the visualization of the distribution of chemical elements and the associated crystalline phases inside complex, heterogeneous materials of extended thickness (millimeter range) in a nondestructive fashion. In this paper, the accuracy and resolution with which the individual layers in a multilayer stack of automotive paints can be distinguished is evaluated, and some of their properties measured. A paint layer system of eight layers was investigated, in which eight different crystalline substances were identified, each layer consisting of an organic, synthetic resin doped with finely milled inorganic compounds that serve as pigments or to strengthen the la...
1976-01-01
This paper illustrates how the properties of environmental particulate matter can be better understood if a multitechnique examination is conducted. Some results for fly ash, using neutron activation analysis, scanning electron microscopy, photoelectron spectroscopy (ESCA), x-ray fluorescence and x-ray diffraction are described. The difference in composition between the surfaces and interiors of particles are discussed and the effects of water leaching on surface composition are shown. The propensity of natural iron oxide substrates to cover themselves with adsorbed material is illustrated; this may be an important factor in the transfer of pollutants on particulate matter surfaces. The final section describes how the element detection sensitivity can be predicted for an improved x-ray fluorescence system that uses monochromatic AgK..cap alpha.. radiation for excitation.
2003-12-01
The aim of this work is to show the analytical possibilities of the PIXE method and more particularly here in this first part to give the theoretical bases of the method. Are discussed respectively: the bases notions, the fluorescent atom, the cross sections, the continuous background noise and the secondary fluorescence. (O.M.)
Hard X-ray micro-spectroscopy at Berliner Elektronenspeicherring fr Synchrotronstrahlung II
2009-01-01
The capabilities of the X-ray beamlines at Berliner Elektronenspeicherring fr Synchrotronstrahlung II (BESSY II) for hard X-ray measurements with micro- and nanometer spatial resolution are reviewed. The micro-X-ray fluorescence analysis (micro-XRF), micro-extended X-ray absorption fine structure (micro-EXAFS), micro-X-ray absorption near-edge structure (micro-XANES) as well as X-ray standing wave technique (XSW), X-ray beam induced current (XBIC) in combination with micro-XRF and micro-diffraction as powerful methods for organic and inorganic sample characterization with synchrotron radiation are discussed. Mono and polycapillary optical systems were used for fine X-ray focusing down to 1m spot size with monochromatic and white synchrotron radiation. Polycapillary based confocal det...
Development and applications of X ray micro focusing optics
The motivation for this thesis is the design and implementation of novel elliptical x-ray reflective micro-focusing optics. The advancement of x-ray micro-beam applications is a primary objective. Sputtering of a heavy metal onto a spherical substrate can produce the required elliptical profile, and the combination of two mirrors in an orthogonal arrangement can deliver intense x-ray micro-beams at an x-ray synchrotron source. It is believed that this new deposition process offers the best way of obtaining accurate elliptical profiles. Traditionally, reflective x-ray micro-focusing has been achieved by bending a smooth flat substrate, and the new deposition technique renders a much simpler experimental arrangement. Moreover, producing enhanced mirror profiles has the opportunity to provide sub-micron focused x-ray beams with larger apertures and longer working distances. Grazing-incidence rhodium-coated spherical substrates were employed to investigate a variety of systems, using several experimental methods: 1) The diamond-anvil cell has provided the opportunity to investigate high-pressure phase-transitions in general. The micro-focused x-ray beam allowed a study of two systems that exhibit abrupt phase-transitions at ultra high-pressures, and a novel x-ray fluorescence spectroscopic measurement was also implemented. 2) Micro-focused x-ray fluorescence imaging was used to spatially resolve the calcium content in normal and osteoarthritic bone. This investigation is a unique application of x-ray micro-beams and correlation with infrared micro-spectroscopy is conceivable. 3) A process known as 'SAG' can control the growth of thin-film semiconductor devices. The material is constrained to within distances that are on the micron length scale, and a micro-focused x-ray beam is essential for growth evaluation.
1998-10-28
As previously reported, when a high-voltage is applied to a Grimm glow discharge tube, high-energy electrons emitted from the cathode surface bombard the glass window, leading to X-ray emissions from the window. In this study, we have applied an energy-dispersive X-ray analysis to detect X-rays from the cathode which are excited by X-rays emitted from the glass window. Thus, we have proposed to utilize this glow discharge tube as a compact X-ray fluorescence instrument, to which both the X-ray emission source and the sample are directly attached. This compact X-ray fluorescence instrument has the same advantages of easy maintenance, exchangeable target and sample, and simple construction. The quantitative determination of Si, Ti, and Mn in Fe-Si, Fe-Ti, and Fe-Mn alloys was demonstrated with the detection limits of 21, 150 and 420 ppm, respectively. The X-ray measurement form the cathode is a useful method to directly monitor the cathode surface during the glow discharge process. This would be applied to understand and control the glow discharge processes. Moreover, the X-ray diffraction peaks as well as the fluorescent X-ray peaks were observed, indicating that the structure analysis of the cathode material would also be possible. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)
1997-01-01
A rapid and precise method was used for the determination of tin in cassiterite ore and tailings from the tin province of Jos Plateau, Nigeria using {sup 241}Am isotopic X-ray source. The application of the method is very attractive when compared to solution methods of analysis. Concentration of the ore samples vary from 60 to 78% while tailings have concentrations of tin from 0.5 to 1.7%. (Author).
2009-01-01
X-ray fluorescence spectrometry due to its nondestructive nature is widely applied in analysis of single layers and multiple layer films (e.g. semiconductors, electrooptic and solar cell devices, coatings, corrosion and paint layers), individual particles (airborne, fly ash, gunshot residue particles, etc.), art and archeological objects (manuscripts, paintings, icons) and many others. Quantitative analysis of these materials, frequently classified as samples of less than infinite thickness (thin or intermediate-thickness samples), required applying adequate matrix correction methods taking into account complex dependence of analyte fluorescent radiation intensity on full matrix composition and sample thickness. In this article, the matrix correction methods including fundamental parameter...
2009-01-01
X-ray fluorescence spectrometry due to its nondestructive nature is widely applied in analysis of single layers and multiple layer films (e.g. semiconductors, electrooptic and solar cell devices, coatings, corrosion and paint layers), individual particles (airborne, fly ash, gunshot residue particles, etc.), art and archeological objects (manuscripts, paintings, icons) and many others. Quantitative analysis of these materials, frequently classified as samples of less than infinite thickness (thin or intermediate-thickness samples), required applying adequate matrix correction methods taking into account complex dependence of analyte fluorescent radiation intensity on full matrix composition and sample thickness. In this article, the matrix correction methods including fundamental parameters, Monte Carlo simulations, influence coefficients ...
X-RAY FLUORESCENCE ANALYSIS OF HANFORD LOW ACTIVITY WASTE SIMULANTS METHOD DEVELOPMENT
2007-01-01
The x-ray fluorescence laboratory (XRF) in the Analytical Development Directorate (ADD) of the Savannah River National Laboratory (SRNL) was requested to develop an x-ray fluorescence spectrometry method for elemental characterization of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) pretreated low activity waste (LAW) stream to the LAW Vitrification Plant. The WTP is evaluating the potential for using XRF as a rapid turnaround technique to support LAW product compliance and glass former batching. The overall objective of this task was to develop an XRF analytical method that provides rapid turnaround time (
1990-01-01
The bleach-fixing kinetics of colour raster coated photopaper was investigated during the developing process. The change in the rate of bleach-fixation with time and the effect of different accelerating materials were studied. The x-ray fluorescence method for measuring the silver content of the photopaper applies 125I isotope as the excitation source. The x-ray fluorescence method and the traditional densitometric methods were compared. (author) 5 refs. 5 figs. 3 tabs
2005-01-01
In this work the colloidal method was chosen to perform the catalysts. This method produces nano catalysts well dispersed in the carbon support. The catalyst systems were performed with platinum, ruthenium, molybdenum, nickel, dysprosium, terbium, samarium and uranium. The method chosen to synthesize catalysts produced binary' and ternary systems with a good distribution of the nano crystals. The quaternary systems performed in this work shows a crystallite size 2 to 3 times greater than the binary and ternary ones. This could indicate that some modifications in the method should be done to improve the electrocatalytic activity of the quaternary systems. The characterization of the catalysts were performed by the following techniques. X-ray fluorescence analysis, X-ray diffraction, X-ray photoelectron spectroscopy, infrared spectroscopy, high resolution ...
Practical applications of activation analysis and other nuclear techniques
Neeutron activation analysis (NAA) is a versatile, sensitive multielement, usually nondestructive analytical technique used to determine elemental concentrations in a variety of materials. Samples are irradiated with neutrons in a nuclear reactor, removed, and for the nondestructive technique, the induced radioactivity measured. This measurement of ..gamma.. rays emitted from specific radionuclides makes possible the quantitative determination of elements present. The method is described, advantages and disadvantages listed and a number of examples of its use given. Two other nuclear methods, particle induced x-ray emission and synchrotron produced x-ray fluorescence are also briefly discussed.
Practical applications of activation analysis and other nuclear techniques
1982-01-01
Neeutron activation analysis (NAA) is a versatile, sensitive multielement, usually nondestructive analytical technique used to determine elemental concentrations in a variety of materials. Samples are irradiated with neutrons in a nuclear reactor, removed, and for the nondestructive technique, the induced radioactivity measured. This measurement of ..gamma.. rays emitted from specific radionuclides makes possible the quantitative determination of elements present. The method is described, advantages and disadvantages listed and a number of examples of its use given. Two other nuclear methods, particle induced x-ray emission and synchrotron produced x-ray fluorescence are also briefly discussed.
PIXE and RIXRF comparison for applications to biological sample analysis
2004-01-01
The different excitation methods of X-ray spectral analysis with proton induced X-ray emission (PIXE) and radioisotope (109Cd) induced X-ray fluorescence (RIXRF) are evaluated and compared with regard to sensitivity, detection limit, precision, accuracy and cost, using NIST orchard leaves and pine needles standard reference materials. The accuracy and precision of both the methods for biological analysis using appropriate standards are shown to be better than 5%. The comparison of sensitivity results indicates that PIXE is comparatively more sensitive for light elements (K to Zn) and RIXRF for heavier elements (Z
Rapid determination of arsenic content in coal from the North Bohemian brown coal basin
1984-01-01
A method developed by the Institute of Geology and Geotechnics of the Academy of Sciences of Czechoslovakia is discussed for determination of arsenic in brown coal from the North Bohemian brown coal basin. The method for X-ray fluorescence analysis of arsenic using a prototype of the 107-1 X-ray fluorescence analyzer with plutonium 238 as radiation source is evaluated. Coal sample preparation, measuring procedure and evaluation of the measurement results are analyzed. Measuring results are given in 3 tables. Practical use of the X-ray fluorescence analysis is described. 10 references.
The space group and the unit cell constants of Eosphorite, a phosphate of iron and manganese, have been determined. The specimens examined are found in the pegmatites of the Rio Jequitinhonha valley, State of Minas Gerais, Brazil. X-ray diffraction methods (powder, Buerger's precession camera, Weissenberg's method), X-ray fluorescence analysis, differential thermal analysis and thermal gravimetric analysis are applied to this phosphate. The space group of Eosphorite is determined to be Bbam and the unit cell constants determined by the Buerger's precession method are: a/sub 0/=/sub 10/.423 A; b/sub 0/=/sub 13/.477 A; c/sub 0/=/sub 6/.975 A; Z=8.
X-ray fluorescence spectrometric analysis of erbium oxide for rare earth impurities
1985-08-01
An x-ray fluorescence spectrometric method was developed for the analysis of high purity erbium oxide for the determination of yttrium, terbium, dysprosium, holmium, thulium, ytterbium and lutetium oxide impurities in the concentration range 0.005-0.1%. The sample is taken in oxalate form, mixed with a binder (boric acid) in the weight ratio 3:1 and made into a double layer pellet. The analysis is done on a Philips PW 1220 x-ray fluorescence spectrometer using a LiF (200) analyzing crystal. The precision at each concentration of the standards and theoretical minimum detection limit for each element were calculated. (author). 3 refs.
2009-01-01
Soil and water samples from the Belene NPP site and Danube river have been analysed and soil composition as well as humus content, pH, mechanical composition of soil ect. For determination of chemical composition of soil the following methods have been used: 1) gamma-activation method - for Zn, Ba, Pb, Ti, Th, U, Na. 2) x-ray fluorescence method - for Sr, Fe, Rb, Zr. 3) atomic absorption methods - for Cr, Co, Mg
Non-destructive measurement of cultural property
1997-02-01
Non-destructive analytical method is favored for the measurement of samples from the field of cultural properties. Among many scientific methods, X-ray fluorescence spectrometry and X-ray diffraction method are frequently applied in this field. X-ray fluorescence spectrometer is the main method for the measurement of chemical composition of cultural properties when sample is not taken out. It is the most important concept during the measurement, that samples should be kept in the safety condition without any difficulty or defect. Because a sample from the field of cultural properties could not be cut or could not be laid down in some cases, instruments should be improved to admit these samples and conditions. It is one of the solutions for this point to equip a large sample chamber in the instrument. Several new instruments with large sample chamber which was specially designed for the cultural properties were explained. Applications of these instruments were also explained for the real archaeological and historical samples. Even the measurements is not quantitative and qualitative analysis only, the results is evaluated to be valuable for the understanding of the samples. The micro focus X-ray fluorescence spectrometer was also applied in this field. The method gave not only the ordinary chemical composition but also the structure of the samples by mapping. (author)
Energy dispersive x-ray fluorescence spectrometric determination of trace elements in oil samples
A method is described for the determination of trace elements in petroleum by energy dispersive x-ray fluorescence spectrometry. Minimum sample preparation is required. This is achieved by making small targets and spiking the sample with a solution of Cr and Rh in H/sub 2/SO/sub 4/ or organo-Rh in mineral oil. Use of two spiking elements with different x-ray energies facilitates the determination of x-ray absorption corrections. In the NBS fuel oil (SRM 1634), V, Fe, Ni, and Mo were detected and the results of the analyses correspond well with the NBS certified values. In the shale oil, Fe, Ni, Zn, As, and Se were detected. The one-element spiking method works well for samples of low viscosity where the sample can be spread on the supporting foil thin enough so that the absorption of measured x-rays can be ignored, whereas the two-element spike is needed for high viscosity samples (NBS fuel oil) where samples cannot be made thin enough to ignore sample absorption.
Energy dispersive x-ray fluorescence spectrometric determination of trace elements in oil samples
1978-06-01
A method is described for the determination of trace elements in petroleum by energy dispersive x-ray fluorescence spectrometry. Minimum sample preparation is required. This is achieved by making small targets and spiking the sample with a solution of Cr and Rh in H/sub 2/SO/sub 4/ or organo-Rh in mineral oil. Use of two spiking elements with different x-ray energies facilitates the determination of x-ray absorption corrections. In the NBS fuel oil (SRM 1634), V, Fe, Ni, and Mo were detected and the results of the analyses correspond well with the NBS certified values. In the shale oil, Fe, Ni, Zn, As, and Se were detected. The one-element spiking method works well for samples of low viscosity where the sample can be spread on the supporting foil thin enough so that the absorption of measured x-rays can be ignored, whereas the two-element spike is needed for high viscosity samples (NBS fuel oil) where samples cannot be made thin enough to ignore sample absorption.
Los Alamos Scientific Laboratory x-ray survey manual
1980-02-01
A manual has been developed by the Health Physics Group to establish procedures for routine testing of industrial and analytical x-ray equipment for compliance with applicable LASL administrative requirements and technical bulletins. Radiation protection survey procedures were developed for the following types of equipment: x-ray diffraction and fluorescence analysis systems, industrial cabinet x-ray systems, industrial noncabinet x-ray systems, and electron microscopes.
Electron-ion-x-ray spectrometer system
The authors describe a spectrometer system developed for electron, ion, and x-ray spectroscopy of gas-phase atoms and molecules following inner-shell excitation by tunable synchrotron radiation. The spectrometer has been used on beamline X-24A at the National Synchrotron Light Source for excitation-dependent studies of Ar L-shell and K-shell photoexcitation and vacancy decay processes. The instrumentation and experimental methods are discussed, and examples are given of electron spectra and coincidence spectra between electrons and fluorescent x-rays.
Calibration of personnel dosimeters
1977-01-01
Methods of calibrating both film and thermoluminescent dosimeters (TLD) to photon and electron radiations are described. K fluorescent x-rays, heavily filtered x-ray beams, and isotope gamma rays are used at the Los Alamos calibration facility to measure the energy and angular response of radiation detectors over a photon energy range of 10 to 1000 keV. Beam spectra, alignment, size and uniformity are discussed. The energy and angular response of dosimeters to electrons is measured with beta-emitting isotopes varying in maximum energy from 770 to 2300 keV.
X-Ray Entangled Photon Production in Collisions of Laser Beams with Relativistic Ions
2010-04-05
A method is suggested to produce, with the help of colliding laser photons with bunches of relativistic ions having two energy levels, both intense beams of monochromatic polarized X-ray fluorescence photons and significant number of X-ray entangled photons, via double Doppler transformation. Nonlinear susceptibility of the ions, the cross section and the rate of production of such photons at RHIC are estimated. Such beams of X-ray photons can be detected and applied to solve various problems, in a manner similar to the usage of optical photons.
X-RAY FLUORESCENCE ANALYSIS OF FILTER-COLLECTED AEROSOL PARTICLES
X-ray fluorescence (XRF) has become an effective technique for determining the elemental content of aerosol samples. For quantitative analysis, the aerosol particles must be collected as uniform deposits on the surface of Teflon membrane filters. An energy dispersive XRF spectrom...
New approach to breast tumor detection based on fluorescence x-ray analysis
A new technical approach to breast-tumor detection is proposed. The technique is based on fluorescence x-ray analysis, and can identify a miniature malignant tumor within the breast. The primary beam...Full Text Available
2009-01-01
The practical use results of sensitivity increase technique in quantitative X-ray fluorescence analysis are presented. The technique is based on the method of maximum like hood and can be used in the cases of the characteristic lines strong overlap and weak spectral lines in noise background. The spectra of mercury and zinc amalgam were analyzed, at first on the test samples of filter paper and than on the test bioassays of blood plasma solid. Absolute error of mercury content detection in bioassays was 2.4 times decreased. Detection limit achieved by the method is 13 ppb, significantly lower than obtained by standard spectral processing procedures
Quality management and method Validation in EDXRF analysis
2007-01-01
Owing to the increased demands from society for reliable/certified analytical results, x-ray fluorescence laboratories face an urgent need for quality management system (QMS) implementation, in particular complying with the general requirements for the competence of testing and calibration laboratories of the latest approved ISO standard (ISO/IEC 17025: 2005). Some specific features of energy dispersive x-ray fluorescence (EDXRF) techniques require a careful interpretation of some concepts related to method validation and quality control. This paper presents some thoughts on how to assess the traceability of the results and to evaluate the characteristics of performance of the analytical methods, including linearity, working range, precision, trueness and detection limits. Typical examples of EDXRF analytical techniques are provided for illustration, as ...
Equipment development using x-ray fluorescence analysis of multi-excitations
2009-01-01
In order to make possible the sensitive analysis of heavy elements ranging from light element, we have developed the energy dispersive X-ray fluorescence method with multi-excited optical system. The excitation source of light element was adopted the monochromator method using DCC (doubly curved crystal). Moreover, the excitation of heavy elements was made to realize EDXRF of simultaneous multi-elements analysis by adoption of the filter method. In this study, in order to improve the detection sensitivity of light elements, for spectroscopic and focusing highly oriented pyrolytic graphite (HOPG (0002)) is used. The irradiated spot size of X-ray was as small as 1 mm diameter, and in order to prevent emission of the lengthwise direction of crystal, the producible doubly curved Johann type was easily used as a concentration technique form that X-ray beams can be collected ...
2004-01-01
A new interpretation of the data from Sweeping-TXRF (total reflection X-ray fluorescence) was proposed for the analysis of semiconductor contamination. Formerly, we focused on the accumulated spectrum that represents average concentration. In the proposed method, the individual spectra are also utilized to obtain rough mapping information for the entire wafer surface. Although the individual integration time of measurement is very short (4-8 s/spot), a limit of detection at the level of 1010 atoms cm-2 is maintained for each spot. This method was used to analyze actual wafers that had particulate contaminants on them, and the capability of particle detection was demonstrated. In addition, this method simultaneously gives the average concentration by using the accumulated spectrum, as reported before. Dedicated software for Sweeping-TXRF ...
Calculating bone-lead measurement variance.
2000-05-01
Full Text Available.The technique of (109)Cd-based X-ray fluorescence (XRF) measurements of lead in bone is well established. A paper by some XRF researchers [Gordon CL, et al. The Reproducibility of (109)Cd-based X-ray Fluorescence Measurements of Bone Lead. Environ Health Perspect 102:690-694 (1994)] presented the currently practiced method for calculating the variance of an in vivo measurement once a calibration line has been established. This paper corrects typographical errors in the method published by those authors; presents a crude estimate of the measurement error that can be acquired without computational peak fitting programs; and draws attention to the measurement error attributable to covariance, an important feature in the construct of the currently accepted method that is flawed under certain circumstances.
A compact XRF unit for determining total sulphur content in coals
A microcomputer based x-ray fluorescence (XRF) unit was developed for off-line determination of total sulphur content in coal samples. The unit consisted of the x-ray exciting/measuring set and the microcomputer with a plug-in interface card, An Fe-55 radioisotope was used as the exciting source while a krypton-filled proportional counter was used to measure x-rays from the samples. The x-ray spectrum was simultaneously displayed on the microcomputer screen. For quantitative determination of sulphur, the intensities of sulphur K x-rays as well as calcium K x-rays and scattered x-rays were taken into account. The unit was tested with finely-ground, dried and compressed lignite, subbituminous and bituminous samples. It was found that for low-calcium coals the results were in good agreement with those obtained from the standard chemical analysis method within {+-}0.2 %S and within {+-}0.5 %S for high-calcium coals.
2010-01-01
By measuring the intensities of the x-ray standing wave induced elastic and inelastic x-ray scattering from thin multilayer structures, we show that structural characterizations of the high and low z (atomic number) material layers can be performed independently. The method has been tested by analyzing the structural properties of an Nb/C/Nb trilayer and an Mo/Si periodic multilayer structure. The results of the x-ray scattering measurements have been compared with those obtained using x-ray reflectivity and conventional x-ray standing wave fluorescence techniques. It has been demonstrated that the present approach is especially suitable for studying multilayer structures comprising low atomic number layers, as it eliminates the requirement of a fluorescence signal, which is very weak in the case of low z materials
Real-time monitoring of arsenic filtration by granular ferric hydroxide
2010-01-01
Contamination of drinking water by arsenic is a serious public health issue in many parts of the world. One recent approach to this problem has been to filter out arsenic by use of granular ferric hydroxide (GFH), an adsorbent developed specifically for the selective removal of arsenic from water. Previous studies have documented the efficiency and high treatment capacity of this approach. We present a novel X-ray fluorescence method to monitor the accumulation of arsenic within a specially designed GFH column, as both a function of time (or water volume) and location along the column. Using a miniature X-ray tube and silicon PiN diode detector, X-ray fluorescence is used to detect characteristic X-rays of arsenic excited from within the GFH. Trials were performed using a water flow rate of approximately 1.5 L per hour, with an added arsenic concentration of approximately 1000 ...
1992-10-01
Synchrotron Radiation induced X-ray micro Fluorescence analysis ({mu}-SRXRF) is compared with more conventional microanalytical techniques such as Secondary Ion Microscopy (SIMS) and Electron Probe X-ray Microanalysis (EPXMA) for two typical microanalytical applications. SRXRF and EPXMA are employed for the analysis of individual particles, showing the complementary character of both techniques. By means of element mapping of trace constituents in a heterogeneous feldspar, the strong and weak points of SRXRF in comparison to EPXMA and SIMS are illustrated. The most striking difference between SRXRF and the other two microanalytical methods is the ability of SRXRF to probe deep into the investigated Material, whereas SIMS and EPXMA only investigate the upper surface of the material. The possibilities of SRXRF at third generation synchrotron rings is also briefly discussed.
1992-01-01
Synchrotron Radiation induced X-ray micro Fluorescence analysis ([mu]-SRXRF) is compared with more conventional microanalytical techniques such as Secondary Ion Microscopy (SIMS) and Electron Probe X-ray Microanalysis (EPXMA) for two typical microanalytical applications. SRXRF and EPXMA are employed for the analysis of individual particles, showing the complementary character of both techniques. By means of element mapping of trace constituents in a heterogeneous feldspar, the strong and weak points of SRXRF in comparison to EPXMA and SIMS are illustrated. The most striking difference between SRXRF and the other two microanalytical methods is the ability of SRXRF to probe deep into the investigated Material, whereas SIMS and EPXMA only investigate the upper surface of the material. The possibilities of SRXRF at third generation synchrotron rings is also briefly discussed.
EDXRF imaging of Pb in glazed ceramics using a micropattern gas detector
2009-01-01
A new system for energy-resolved X-ray fluorescence imaging using a microhole and strip plate (MHSP), a new type of micropattern gas detector (MPGD), is proposed. It works as a single photon counting detector with position and energy detection capability. The interaction of X-rays with the gas medium produces electrons via the photoelectric effect, and the number of electrons is proportional to the absorbed X-ray energy. These electrons are further multiplied in the MHSP. Position detection is achieved using the charge division method. The detector has an active area of 2828mm2 and shows good position resolution, about =125m, an intrinsic energy resolution of about 14% FWHM for 5.9keV X-rays, and a counting rate capability of up to 0.5MHz. The system has shown goo...
Chemical characterization of SiCxNy nanolayers by FTIR-and Raman spectroscopy, XPS and TXRF-NEXAFS
2009-01-01
SiCxNy nanolayers were synthesized by a remote plasma enhanced chemical vapour deposition (RPECVD) method and chemically characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and near-edge X-ray absorption fine structure investigations in total reflection X-ray fluorescence geometry (TXRF-NEXAFS). The results are compared with those obtained for standard samples SiC and Si3N4 (and with spectra from the literature). As a first result, two or more compounds containing Si-N bonds (not Si3N4), one compound with a Si-C bond (not SiC), and graphitic carbon were identified
Total reflection x-ray analysis of metals in blood samples
2009-01-01
The sample preparation for TXRF (total reflection X-ray fluorescence) quantitative analysis of trace elements in human blood samples was investigated. In the TXRF analysis, a solution sample is dropped and dried on a flat substrate, and then the dried residue is measured. In this case, the dried residue should be flat not to disturb X-ray total reflection on the substrate. In addition, it is required to simply measure the whole blood sample by TXRF method, although a serum is analyzed in many cases. Thus, we studied the optimum conditions of the sample preparation of the whole blood by adding the pure water to apply Hemolysis phenomenon, where blood cells are destroyed due to different of the osmotic pressure, leading to flat residue. It was found that the best S/B ratio was obtained when the whole blood was diluted 8 times with pure water. Moreover, it was investigated the influence of ...
Soft x-ray magnetic circular dichroism: A probe for studying paramagnetic bioinorganic systems
1993-10-15
Soft x-ray magnetic circular dichroism was used to study a paramagnetic bioinorganic system. The authors measured the Fe L edges of Pyrococcus furiosus rubredoxin, using circularly polarized synchrotron radiation, a split-coil superconducting magnet, low sample temperatures, and fluorescence detection. The observed dichroism effect is strong (30%) and in general agreement with the calculation. The method is element- and oxidation state-specific, and the data can be interpreted by established theoretical procedures. Soft x-ray magnetic circular dichroism demonstrates enormous potential as a probe for studying paramagnetic systems in biology, chemistry, and material science. 24 refs., 2 figs.
Radioactive sample effects on EDXRF spectra
2008-01-01
Energy dispersive X-ray fluorescence (EDXRF) is a rapid, straightforward method to determine sample elemental composition. A spectrum can be collected in a few minutes or less, and elemental content can be determined easily if there is adequate energy resolution. Radioactive alpha emitters, however, emit X-rays during the alpha decay process that complicate spectral interpretation. This is particularly noticeable when using a portable instrument where the detector is located in close proximity to the instrument analysis window held against the sample. A portable EDXRF instrument was used to collect spectra from specimens containing plutonium-239 (a moderate alpha emitter) and americium-241 (a heavy alpha emitter). These specimens were then analyzed with a wavelength dispersive XRF (WDXRF) instrument to demonstrate the differences to which sample radiation-induced X-ray emission affects the detectors on these two types of XRF instruments.
2001-09-01
X-ray diffraction and fluorescent investigations of human hair were carried out using SR of VEPP-3. The small-angle techniques were used for ecological monitoring and medical diagnostics of pathological states of human organisms with the usage of non-invasive methods for express analysis of biological objects, including human and animal tissues: nails, wool and hair samples. Possibility using of hair fibre diffraction to test for pathological conditions is the subject of this paper. X-ray diffraction data allowed us to suppose the two-component structural model of the hair tissue.
Application of X-ray emission techniques for monitoring environmental pollution
1997-10-01
X-ray emission techniques are versatile and powerful methods used for multielement non-destructive analysis. They include X-ray fluorescence (XRF), particle induced X-ray emission (PIXE), scanning electron microscopy combined with X-ray spectrometry and electron probe microanalysis (EPMA). Since many years the IAEA has utilised and promoted these techniques for the analysis of environmental, biological and geological samples. In this paper recent progress at our laboratory in selected aspects related to the application of X-ray emission techniques is briefly overviewed. (authors) 12 refs., 3 figs., 7 tabs.
A method for measuring dark current electron beams in an rf linac
1993-12-31
X-ray fluorescence from thin foils inserted into the NPS linac has been used to measure the integrated electron beam intensity when the accelerator is operating with dark current. The measured x-ray flux, the known inner shell ionization cross sections and radiative transition probabilities are used to obtain measurements of dark currents of the order of 10{sup -14} amperes. The same arrangement allows continuous, in-situ energy calibration of our SiLi detector in the electromagnetic noise environment of the linac. This technique was orginally developed to perform absolute production efficiency measurements of parametric x-ray generation in the 5-50 keV range.
Microanalysis of solid samples by total-reflection x-ray fluorescence spectrometry
Microgram quantities of different solid powders and smears of alloys were analyzed with total-reflection x-ray fluorescence spectrometry, a special variant of energy-dispersive x-ray fluorescence spectrometry. The samples were analyzed directly without chemical pretreatment. The method works simultaneously for about 20 elements. Quantitative analysis with internal standardization was executed with 10-50 mg of sample mass, but only microgram quantities were necessary for the determination. The dynamic range of the method is about 4 orders of magnitude; detection limits are in the microgram-per-gram region. Results for standard reference materials such as coal fly ash, bovine liver, tomato leaves, and electric furnace dust are reported. Relative standard deviations mostly below 15% are found for the repeatability. Relative deviations from the certified values which characterize the accuracy are of the same order of magnitude.
Microanalysis of solid samples by total-reflection x-ray fluorescence spectrometry
1987-11-01
Microgram quantities of different solid powders and smears of alloys were analyzed with total-reflection x-ray fluorescence spectrometry, a special variant of energy-dispersive x-ray fluorescence spectrometry. The samples were analyzed directly without chemical pretreatment. The method works simultaneously for about 20 elements. Quantitative analysis with internal standardization was executed with 10-50 mg of sample mass, but only microgram quantities were necessary for the determination. The dynamic range of the method is about 4 orders of magnitude; detection limits are in the microgram-per-gram region. Results for standard reference materials such as coal fly ash, bovine liver, tomato leaves, and electric furnace dust are reported. Relative standard deviations mostly below 15% are found for the repeatability. Relative deviations from the certified values which characterize the accuracy are of the same order of magnitude.
1995-12-31
Total Reflection X-Ray Fluorescence (TYRF) Spectroscopy instrumentation has recently become available on the U.S. commercial market. This x-ray excited method is touted for its sensitivity (parts per trillion), quantitative ability without the need for multi-element standards and lack of response change to matrix element differences. It has been promoted for use in forensic science and on environmental samples. This paper will discuss the results of a blind studies, wherein well characterized samples of forensic interest and environmental water proficiency tests were submitted for determination of elemental composition and concentration. The results indicate that this instrumentation should be considered by those laboratories analyzing materials at low (trace) concentrations or small (microscopical) size.
In Vivo X-Ray Fluorescence Microtomographic Imaging of Elements in Single-Celled Fern Spores
2007-01-01
We have observed in vivo three-dimensional distributions of constituent elements of single-celled spores of the fern Adiantum capillus-veneris using an X-ray fluorescence computed microtomography method. The images of these distributions are generated from a series of slice data, each of which is acquired by a sample translation-rotation method. An incident X-ray microbeam irradiates the sample with a spot size of 1 mum. The high Ca concentration in the testa and the localized and overlapping Fe and Zn concentrations inside the spore are shown in three-dimensional images. The K concentration is high throughout the cell, and there are localized regions of higher density. The atomic number densities of these elements in the testa and inside the cell in a tomographic slice are estimated with a resolution of about 1 mum
Handbook of practical X-ray fluorescence analysis
2006-01-01
X-ray fluorescence analysis (XRF) is a reliable multi-elemental and nondestructive analytical method widely used in research and industrial applications. This practical handbook provides self-contained modules featuring XRF instrumentation, quantification methods, and most of the current applications. The broad spectrum of topics is due to the efforts of a large number of authors from a variety of different types of institutions such as universities, research institutes, and companies. The book gives a survey of the theoretical fundamentals, analytical instrumentation, software for data processing, various excitation regimes including gracing incidents and microfocus measurements, quantitative analysis, applications in routine and micro analysis, mineralogy, biology, medicine, criminal investigations, archeology, metallurgy, abrasion, ...
1998-01-01
Energy-dispersive X-ray fluorescence (EDXRF) is a widely applied technique for both laboratory and field-based characterization of metals in complex matrices. Here an EDXRF method is described for analysis of 13 hazardous (RCRA) metals in Portland cement, a typical matrix for transuranic (TRU) waste from US Department of Energy (DOE) sites. Samples are analyzed as homogeneous powders prepared by simple drying, mixing, and milling. Analyses are performed using a commercial EDXRF spectrometer equipped with an X-ray tube, a high-resolution Si(Li) detector, and fundamental parameters software for data reduction. The spectrometer is rugged and suitable for use in either mobile or fixed-based laboratories. Standardization is accomplished using fundamental parameters techniques for several prepared standards which bracket the expected range in metal ...
2003-01-01
The recently developed dry method for the element determination of single freshwater microcrustacean specimens (Daphnia) using total reflection X-ray fluorescence (TXRF) spectrometry showed that inhomogeneities of the biological material on the glass carriers resulted in some cases in high background and hampered the detection of certain trace elements (e.g. Cr, Ni). The aim of this study was to test how inhomogeneities of the biological material can be reduced using cold plasma ashing (CPA) techniques. For that, single specimens of the microcrustacean Daphnia pulex prepared according to the dry method were measured by TXRF before and after CPA. To determine the efficiency of the removal of organic matrix, the background and signal-to-background relationship of 28 samples were analyzed. The results showed (1) a highly significant reduction of the background by CPA ...
Chemical analysis of coal by energy dispersive x-ray fluorescence utilizing artificial standards
1982-01-01
Accurate determinations of the elemental composition of coal by classical methods can be quite difficult and are normally very time consuming. X-ray fluorescence utilizing the powder method, however, has the ability of providing accurate and rapid analyses. Unfortunately, well characterized standards, although available, are not plentiful. In addition, the durability of stability of ground and pelletized coal samples is poor resulting in deterioration with time. As a result, artificial coal standards were prepared from certified geological materials by fusing in lithium tetraborate in percentages approximating expected ash contents and compositions in coal. Since the lithium tetraborate comprises about the same percentage of the standard as does the carbon, hydrogen, and oxygen in coal, the ground and pelletized coal sample can be assayed against the fused calibration curves by compensating for the differences in the mass absorption coefficients of the two matrices. 5 figures, 4 tables.
Arsenic speciation study using x ray fluorescence and cathodic stripping voltammetry
2006-01-01
Two methods for the determination of total As concentration and its inorganic species by Energy Dispersive X Ray Fluorescence (EDXRF) and Cathodic Stripping Voltammetry (CSV) were developed. The determination of arsenic by XRF includes a previous precipitation step of As (III) with APDC. The effect of pH on As (III) recovery was studied. The reduction of As(V) to As(III) with sodium tio sulphate was necessary in order to determine the total As concentration. As(V) concentration was calculated by difference between total As and As(III) concentration. The quantification was done using the thin layer approach. On the other hand, a polarographic method, using CSV was employed. As(III) deposition on the electrode was enhanced by addition of Se(IV). Factors affecting As determination (selenium concentration, deposition potential, deposition time) were studied
2009-08-01
A method for thickness determination of thin amalgamable metallic films by total-reflection X-ray fluorescence (TXRF) is presented. The peak's intensity in TXRF spectra are directly related to the surface density of the sample, i.e. to its thickness in a homogeneous film. Performing a traditional TXRF analysis on a thin film of an amalgamated metal, and determining the relative peak intensity of a specific metal line, the layer thickness can be precisely obtained. In the case of gold thickness determination, mercury and gold peaks overlap, hence we have developed a general data processing scheme to achieve the most precise results.
2009-01-01
A method for thickness determination of thin amalgamable metallic films by total-reflection X-ray fluorescence (TXRF) is presented. The peak's intensity in TXRF spectra are directly related to the surface density of the sample, i.e. to its thickness in a homogeneous film. Performing a traditional TXRF analysis on a thin film of an amalgamated metal, and determining the relative peak intensity of a specific metal line, the layer thickness can be precisely obtained. In the case of gold thickness determination, mercury and gold peaks overlap, hence we have developed a general data processing scheme to achieve the most precise results
2010-01-01
Grazing Incidence X-ray Fluorescence Analysis (GIXRF) is a powerful technique for depth-profiling and characterization of thin layers in depths up to a few hundred nanometers. By measurement of fluorescence signals at various incidence angles Grazing Incidence X-ray Fluorescence Analysis provides information on depth distribution and total dose of the elements in the layers. The technique is very sensitive even in depths of a few nanometers. As Grazing Incidence X-ray Fluorescence Analysis does not provide unambigous depth profile information and needs a realistic input depth profile for fitting, in the context of the EC funded European Integrated Activity of Excellence and Networking for Nano and Micro-Electronics Analysis (ANNA) Grazing Incidence X-ray Fluorescence Analysis is used as a ...
Speciation of rhenium and radiogenic osmium in molybdenite by sensitive XAFS
2006-01-01
For the speciation of trace elements in rocks and minerals, fluorescence XAFS using energy-dispersive Ge detector has been often used. By this method, however, high quality fluorescence XAFS cannot be obtained under intense scattering and/or fluorescence from other predominant elements in the samples. To deal with this problem, we developed a system for fluorescence XAFS using a bent crystal analyzer to selectively extract fluorescence x-rays of a target element. In this paper, speciation of Os in molybdenite has been studied as an example of the application. Radiometric dating using various radioactive decay systems has been widely applied to various terrestrial and extraterrestrial materials. Although the information is closely related to chemical stabilities of parent and daughter nuclides and the reliability of the radiometric dating, there have been few ...
The changes in the fluidity of erythrocyte membranes following x irradiation were investigated with the aid of a fluorescent aromatic hydrocarbon, pyrene. The method used in the present experiments, pyrene excimer fluorescence, is based upon the microviscosity dependence of the lateral diffusion rate of the probe in the membrane plane. The lateral diffusion rate obtained by this fluorescence technique can provide valuable information about the fluidity of the membrane environment of the probe. It was found that the excimer/monomer ratio, a parameter of the lateral diffusion rate, of pyrene bound to erythrocyte membranes irradiated with x rays was higher than that in unirradiated membranes. This effect was observable when 100 R were given to the membranes. In addition, the fluorescence polarization of membrane-bound pyrene decreased in x-irradiated membranes. From these results it was concluded that x irradiation can induce an increase in the fluidity of the hydrocarbon regions of the membranes.
1979-12-01
The changes in the fluidity of erythrocyte membranes following x irradiation were investigated with the aid of a fluorescent aromatic hydrocarbon, pyrene. The method used in the present experiments, pyrene excimer fluorescence, is based upon the microviscosity dependence of the lateral diffusion rate of the probe in the membrane plane. The lateral diffusion rate obtained by this fluorescence technique can provide valuable information about the fluidity of the membrane environment of the probe. It was found that the excimer/monomer ratio, a parameter of the lateral diffusion rate, of pyrene bound to erythrocyte membranes irradiated with x rays was higher than that in unirradiated membranes. This effect was observable when 100 R were given to the membranes. In addition, the fluorescence polarization of membrane-bound pyrene decreased in x-irradiated membranes. From these results it was concluded that x irradiation can induce an increase in the fluidity of the hydrocarbon regions of the membranes.
The energy-dispersive x-ray fluorescence analysis (XRFA) technique has been implemented at several spent nuclear fuel reprocessing facilities for nondestructive measurements of uranium and/or plutonium concentrations in process streams and product storage tanks. An important factor in these quantitative measurements is the absorption of the fluoresced x-rays by the solution matrix, which must be taken into account to accurately quantify the U or Pu concentrations. We describe a new, accurate method using a dual transmission source of Gd-153 and Co-57 to correct for matrix effects. Results of measurements on uranium and plutonium solution standards show the methodology to be better than 0.5%, which includes statistical precision, over the concentration range from 1 to 250 g/l. 5 refs., 4 figs., 3 tabs.
1987-11-24
The energy-dispersive x-ray fluorescence analysis (XRFA) technique has been implemented at several spent nuclear fuel reprocessing facilities for nondestructive measurements of uranium and/or plutonium concentrations in process streams and product storage tanks. An important factor in these quantitative measurements is the absorption of the fluoresced x-rays by the solution matrix, which must be taken into account to accurately quantify the U or Pu concentrations. We describe a new, accurate method using a dual transmission source of Gd-153 and Co-57 to correct for matrix effects. Results of measurements on uranium and plutonium solution standards show the methodology to be better than 0.5%, which includes statistical precision, over the concentration range from 1 to 250 g/l. 5 refs., 4 figs., 3 tabs.
Mapping Metal Elements of Shuangbai Dinosaur Fossil by Synchrotron X-ray Fluorescence Microprobe
2008-01-01
The metal elements mapping of Shuangbai dinosaur fossil, was obtained by synchrotron x-ray fluorescence (SXRF). Eight elements, Ca, Mn, Fe, Cu, Zn, As, Y and Sr were determined. Elements As and Y were detected for the first time in the dinosaur fossil. The data indicated that metal elements are asymmetrical on fossil section. This is different from common minerals. Mapping metals showed that metal element As is few. The dinosaur most likely belongs to natural death. This is different from Zigong dinosaurs which were found dead from poisoning. This method has been used to find that metals Fe and Mn are accrete, and the same is true for Sr and Y. This study indicated that colloid granule Fe and Mn, as well as Sr and Y had opposite electric charges in lithification process of fossils. By this analysis, compound forms can be ascertained. Synchrotron light source x-ray fluorescence is a ...
2009-01-01
In clinical service laboratories, one of the most common analytical tasks with regard to inorganic traces is the determination of the nutrition-relevant elements Fe, Cu, Zn, and Se. Because of the high numbers of samples and the commercial character of these analyses, a time-consuming sample preparation must be avoided. In this presentation, the results of total reflection X-ray fluorescence measurements with a low-power system and different sample preparation procedures are compared with those derived from analysis with common methods like Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The results of these investigations indicate that the optimal total reflection X-ray fluorescence analysis of the nutrition-relevant elements Fe, Cu, Zn, and Se can be performed by preparing whole blood and serum samples after ...
1997-02-01
High resolution x-ray microscopy has been made possible in recent years primarily by two new technologies: microfabricated diffractive lenses for soft x-rays with about 30-50 nm resolution, and high brightness synchrotron x-ray sources. X-ray microscopy occupies a special niche in the array of biological microscopic imaging methods. It extends the capabilities of existing techniques mainly in two areas: a previously unachievable combination of sub-visible resolution and multi-micrometer sample size, and new contrast mechanisms. Because of the soft x-ray wavelengths used in biological imaging (about 1-4 nm), XM is intermediate in resolution between visible light and electron microscopies. Similarly, the penetration depth of soft x-rays in biological materials is such that the ideal sample thickness for XM falls in the range of 0.25 - 10 {mu}m, between that of VLM and EM. XM is therefore valuable for imaging of intermediate level ultrastructure, requiring sub-visible resolutions, in intact cells and subcellular organelles, without artifacts produced by thin sectioning. Many of the contrast producing and sample preparation techniques developed for VLM and EM also work well with XM. These include, for example, molecule specific staining by antibodies with heavy metal or fluorescent labels attached, and sectioning of both frozen and plastic embedded tissue. However, there is also a contrast mechanism unique to XM that exists naturally because a number of elemental absorption edges lie in the wavelength range used. In particular, between the oxygen and carbon absorption edges (2.3 and 4.4 nm wavelength), organic molecules absorb photons much more strongly than does water, permitting element-specific imaging of cellular structure in aqueous media, with no artifically introduced contrast agents. For three-dimensional imaging applications requiring the capabilities of XM, an obvious extension of the technique would therefore be computerized x-ray microtomography (XMT).
1999-01-01
A method of manufacturing thin-film emitters from organic extracts based on a block copolymer of polysiloxane and polycarbonate was proposed. A procedure was developed for the solvent extraction-X-ray-fluorescence determination of 0.005 mg/l selenium and 0.0025 mg/l arsenic in drinking water (for concentrations of arsenic or selenium of 0.05-0.1 mg/l, RSD = 5-8 %. Systematic errors by the 3t value are insignificant
2008-01-01
In this paper we present a procedure allowing total-reflection X-ray fluorescence spectrometry (TXRF) determinations of arsenic in water samples, especially in seawater samples. The procedure consists of an arsenate reduction step (performed by using a L-cysteine solution) followed by a complexation of As+3 with sodium dibenzyldithiocarbamate and solid phase extraction. The new procedure is a modification of a method developed by Prange and allows a simultaneous determination of As together with V, Fe, Ni, Cu, Zn, Pb, and U in seawater by TXRF. The procedure was tested using the Certified Reference Material CASS-4 and was later applied to regular seawater samples collected from the North Sea. The detection limit for arsenic is 10 ng L-1
XRF technology exploring on some aeromagnetism abnormal ground of Xinjiang
2006-01-01
Introduce the application in the mine exploring of field on-the-spot with X ray fluorescence analysis instrument (XRF) of new generation. Discuss the principle of XRF and influence factors while exploring on live mainly: base matrix effect, moisture effect and roughness effect, etc.. It is proved through the experiment that the detection limits of copper, zinc and arsenic are 10 10-6 in a portable many-element X-ray fluorescence appearances of new generation. In the aspects of soil of field, normal position of rock analysis and demand of investigating and verifying etc, it has important function. It comes to a conclusion that the XRF technology is a fast economic and efficient geological method. (authors)
X-ray fluorescence in IAEA Member States: Slovenia
2002-01-01
Full text: Research and development activities include: - development of quantification software for radioisotope and tube excited X-ray fluorescence spectrometry, based on use of fundamental parameters and emission-transmission method. - development of sensitive XRF technique for aerosol analysis, utilising excitation at small incident angles. - development of fast semi-quantitative analysis of samples in powder form by TXRF. - designing and manufacturing of portable XRF systems with radioisotope and tube excitation for use in archaeometry and for the analysis of pigments on paintings. Applications: - analysis of geological samples (geochemistry applications). - determination of P, S, Cl, K, Ca and some heavy metals in animal food (hay, grass silage and maize silage). - routine aerosol analysis in urban areas close to industrial facilities. - analysis of ...
Recent trends in total reflection X-ray fluorescence spectrometry for biological applications
2009-01-01
This review is focused on the application of total reflection X-ray fluorescence (TXRF) spectrometry in the field of biological research. In the last decade, most papers were published by authors who applied laboratory-scale TXRF equipments. The application of synchrotron radiation as excitation source (SR-TXRF) shows a slowly increasing tendency. In the cited papers the micro-, trace and multielement capability of these TXRF techniques was demonstrated in the clinical and medical laboratory practice, as well as in various plant physiological studies. For speciation of elements in biological matrices, the TXRF was used as element specific detector following an off-line separation step (e.g., thin layer chromatography, high performance liquid chromatography), however, these off-line methods are not competitive with the on-line coupled HPLC-inductively coupled ...
Polarized Energy Dispersive X-ray Fluorescence Applications of Spice Samples
2009-01-01
In this study, the elemental concentrations of some spice plants gathered from Mut-Mersin in Turkey were analyzed by polarized energy dispersive x-ray fluorescence (PEDXRF) spectrometry. The analyzed spices are peppermint (Mentha piperita), thyme (Thymus vulgaris), and sumac (Rhus glabra). These samples are very often used in the preparation of Turkish foods. The spice samples are indispensable in foods for Turkish people. The results of the analysis show that each sample has different compositions, and some of these elements have a great benefit in human health. The spice samples results reveal that the PEDXRF method is more reasonably sensitive in the determination of the elemental composition of the plants.
1997-05-02
Two dimensional distribution of mercury (Hg) in hair samples of rats exposed to methylmercury (MeHg) was analyzed by synchrotron radiation X-ray fluorescence (SR-XRF) imaging. Experiments with endogenous- and exogenous-model for MeHg exposure revealed that the metal level was obviously higher in the hair cortex after the former exposure whereas a dominant site that Hg distributed after the latter exposure was the cuticle. The method also provided us the Hg profile along the hair length with a single hair obtained by the endogenous model. Thus application of SR-XRF analysis to hair sample would facilitate biological monitoring to not only distinct Hg exposure but also determine its dynamics with only the specimen. 12 refs., 7 figs.
Fast neutron activation analysis and radioisotope X-ray fluorescence study on KALEWA and NAMMA coal
1981-01-01
Kalewa coal was studied with Fast Neutron Activation Analysis (FNAA) technique, employing KAMAN A-710 neutron generator and HP(Ge) detector coupled to ''Canberra'' series 30 MCA. Sequential irradiation and dual aluminium foil monitoring method was employed. Simultaneous multielement analysis was carried out. Namma Coal was studied with radioisotope X-ray Fluorescence (XRF) technique, employing Co-57 exciter source and HP(Ge) detector coupled to ''Canberra'' series 40 MCA. In both FNAA and XRF study, the results obtained were compared to that obtained with Atomic Absorption Spectrophotometry (AAS) technique. Finally, the results were reviewed together with those obtained from similar work on coal with FNAA and XRF techniques. (author)
Experience in element determination in refractory clays using BARS-1 and BRA-7M analyzers
1983-01-01
Methods of X-ray fluorescence analysis of refractory clays for aluminium and iron oxides using BARS-1 and BRA-7M X-ray analyzers are considered. X-ray tubes and cadmium-109 isotope have been used as primary radiation sources. Calibration diagrams to determine Fe/sub 2/O/sub 3/ and Al/sub 2/O/sub 3/ concentration in refractory clays using BARS-1 and BRA-7M are presented. Comparison of the results of X-ray fluorescence and chemical analyses of powder and pellet samples of clays is made. The accuracy is satiscactory.
2010-01-01
Finely laminated sediment cores from two Arctic lakes were investigated using the Itrax Core Scanner that provides micro X-ray fluorescence (?-XRF) measurements with a spatial resolution of 100?m. We compared these chemical measurements with standard geochemical methods using, at the macroscopic scale, inductively coupled plasmaatomic emission spectrometry (ICP-AES) and, at the microscopic scale, energy dispersive spectroscopy (EDS). We also investigated the relationship between the chemical profiles and the grain size of sediments at macro-scale using laser particle-size analysis, and at microscopic scale, using thin section image analysis techniques. Results show a link between grain size and the relative abundance of several elements. Silicon and zirconium are associated with ve...
2008-01-01
The concentrations of Ni, Cu, Zn, and Pb in human scalp hair of 281 individuals working in 10 Syrian industrial plants were determined using co-precipitation by ammoniumpyrolidinedithiocarbamate (APDC) method for total reflection X-ray fluorescence (TXRF) analysis. The results were compared to data obtained for a control group consisted of individuals working at the Syrian Atomic Energy Commission and also to data reported in the literature. The results given by the group of workers in battery plant showed that Pb concentration in human scalp hair samples were higher than those for control group, while some abnormal concentrations were obtained for Cu, Zn and Ni in cables, printing and battery plants, respectively. Normal concentrations of these elements were obtained for hair workers in o...
Determination of metallic impurities in U3O8 using energy dispersive X-ray fluorescence spectrometry
2008-01-01
In order to examine the capability of energy dispersive X-ray fluorescence spectrometry for the determination of some common metallic impurities in nuclear grade U3O8 matrix, a series of synthetic U3O8 standards, containing impurities such as Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni ,V, W and Zn in the concentration range, 1001000g/g, were prepared. Using these standards, calibration curves were set up for different elements after optimizing the spectrometer parameters. Two synthetic samples and five reference standards obtained through an inter-laboratory comparison exercise within analytical laboratories of Department of Atomic Energy, India were analyzed to evaluate the performance of the newly developed analytical methods. The estimates for most of the analytes were in good agreement with...
2010-01-01
The determination of arsenic in water samples requires techniques of high sensitivity. Total Reflection X-Ray Fluorescence (TXRF) allows the determination but a prior separation and pre-concentration procedure is necessary. Alumina is a suitable substrate for the selective separation of the analytes. A method for separation and pre-concentration in alumina, followed by direct analysis of the alumina is evaluated. Quantification was performed using the Al-Ka and Co-Ka lines as internal standard in samples prepared on an alumina matrix, and compared to a calibration with aqueous standards. Artificial water samples of As (III) and As (V) were analyzed after the treatment. Fifty milliliters of the sample at ppb concentration levels were mixed with 10mg of alumina. The pH, time and temperature ...
Combined fluorescence and phase contrast imaging at the Advanced Photon Source
2006-01-01
X-ray fluorescence microprobes excel at detecting and quantifying trace metals in biological and environmental science samples, but typically do not detect low Z elements such as carbon and nitrogen. Therefore, it is hard to put the trace metals into context with their natural environment. We are implementing phase contrast capabilities with a segmented detector into several microprobes at the Advanced Photon Source (APS) to address this problem. Qualitative differential phase contrast images from a modified soft x-ray detector already provide very useful information for general users. We are also implementing a quantitative method to recover the absolute phase shift by Fourier filtering detector images. New detectors are under development which are optimized for the signal levels present at the APS. In this paper, we concentrate on fundamental signal to noise ...
2008-11-15
In this paper we present a procedure allowing total-reflection X-ray fluorescence spectrometry (TXRF) determinations of arsenic in water samples, especially in seawater samples. The procedure consists of an arsenate reduction step (performed by using a L-cysteine solution) followed by a complexation of As{sup +3} with sodium dibenzyldithiocarbamate and solid phase extraction. The new procedure is a modification of a method developed by Prange and allows a simultaneous determination of As together with V, Fe, Ni, Cu, Zn, Pb, and U in seawater by TXRF. The procedure was tested using the Certified Reference Material CASS-4 and was later applied to regular seawater samples collected from the North Sea. The detection limit for arsenic is 10 ng L{sup -1}.
A case study on uptake of thorium from soil to plant by using X-ray fluorescence spectrometry
1997-01-01
A case study was carried out to determine the uptake of thorium from soil to plant by using X-ray fluorescence technique. The radioecological experiment was undertaken to provide plant/soil concentration ratio (CR) data for thorium using 2 types of plant (barley and common vetch) x 4 levels of Th(0, 1500, 3000, 4500 ppm) x 2 types of soil (acidic and alkaline) with different configuration parameters. The calibration of the analytical method for thorium on dry basis of samples is described by using 109Cd excitation source. The results indicated that the CR values decreased with the corresponding Th concentration in soils with a 1000 fold range and differed among soil and plant types. (author)
Method of loading organic materials with group III plus lanthanide and actinide elements
Disclosed is a composition of matter comprising a tributyl phosphate complex of a group 3, lanthanide, actinide, or group 13 salt in an organic carrier and a method of making the complex. These materials are suitable for use in solid or liquid organic scintillators, as in x-ray absorption standards, x-ray fluorescence standards, and neutron detector calibration standards.
Contribution to the sample preparation in the radionuclide X-ray fluorescence analysis of hair
1989-01-01
Methods of sample treatment in XRF analysis of hair are studied in view of the effect on analytical results. A new method is proposed based on the incomplete ashing of hair followed by pellet preparation. Its suitability is estimated on the XRF analysis of real hair samples collected from 4 healthy adults. (author) 12 refs. 4 figs. 1 tab
2002-07-01
Development of the new technologies has been using a lot of substances composed by metals, consequently generating reject for the environment. There is nowadays a concern in management and to control processes that contribute to the environmental degradation. This paper has the purpose to establish an analysis method for the quantitative determination of major and trace elements soil used the Technique of Wavelength Dispersion X-ray Fluorescence Spectrometry (WDRXFS) and the Fundamental Parameters Method. This method allows calculating the theoretical fluorescent intensities obtained by the measured intensities of the elements present in the sample, through the instrumental sensibility. Advantages of this methodology are: use of small amount of sample, accuracy high and sensibility in the determinations studied analyte; not use of chemical treatments in the preparation of samples; speed and cost relatively low. Methodology was validated by the analyze of five certified reference materials, CRM-2704 - Buffalo River Sediment (NIST), JB2, JG1 and JG1a - Geological Survey of Japan (GSJ) and SL-3 -Lake Sediment (IAEA). An X- Ray Fluorescence Spectrometer RIGAKU was used, RIX 3000, 1996 of the Laboratory X-Ray Fluorescence, Center of Chemistry and environment of the Institute of Energy and Nuclear Researches of Sao Paulo. The detection limit for major elements is 0,01-0,2% and trace elements 5 {mu}g/g-100 {mu}g/g. The analytes studied were: SiO2, TiO2, Al2O3, Fe2O3, MnO, MgO, CaO, Na2O, K2O, P2O5, Ag, As, Cd, Ce, Cr, Cu, Ga, Hg, La, Nd, Ni, Pb, Rb, Se, Sr, V, Y, Zn and Zr. (author)
2010-01-01
The possibility of applying Total Reflection X-ray Fluorescence for qualitative and quantitative differentiation of documents printed with rare earth tagged and untagged inks has been explored in this paper. For qualitative differentiation, a very small amount of ink was loosened from the printed documents by smoothly rubbing with a new clean blade without destroying the manuscript. 50 muL of Milli-Q water was put on this loose powder, on the manuscript, and was agitated by sucking and releasing the suspension two to three times with the help of a micropipette. The resultant dispersion was deposited on quartz sample support for Total Reflection X-ray Fluorescence measurements. The Total Reflection X-ray Fluorescence spectrum of tagged and untagged inks could be clearly differentiated. In order to see the applicability of Total Reflection X-ray Fluorescence ...
Validation of fluorescence transition probability calculations
2009-12-10
A systematic and quantitative validation of the K and L shell X-ray transition probability calculations according to different theoretical methods has been performed against experimental data. This study is relevant to the optimization of data libraries used by software systems, namely Monte Carlo codes, dealing with X-ray fluorescence. The results support the adoption of transition probabilities calculated according to the Hartree-Fock approach, which manifest better agreement with experimental measurements than calculations based on the Hartree-Slater method.
2008-01-01
A method of the X-ray spectrum recovery from the data of experimental spectrometric information obtained upon X-ray scattering on light targets is considered. The method is illustrated for MFP procedure and different types of the spectrometers. An integrated procedure of X-ray fluorescence analysis is suggested for various samples without sample preparation. The efficiency of the procedure is verified by the data of quantitative analysis of calibration standards of alloys involving transition metals, lead, and sulfur
2008-01-01
Two methods are utilized to correct the influence of the mineralogical effect on the calibration of elements in geological samples when the pressed powder pellet method is used in wavelength dispersive X-ray fluorescence analysis. The first method involves checking of the 2theta angle for the analyzed element in each sample to correct peak shift and the second method involves replacing the peak intensity with the peak area of the analytical line, so to correct for any shape distortion of the peak. The results were compared with those obtained from the normal method. Major elements in 27 Chinese Certified Reference Materials (CRMs) of rocks, soils and sediments were calibrated with a linear regression curve without theoretical or empirical coefficients. In view of the K values, the calibrations of all 8 elements were improved by the first method and those of 6 ...
2006-01-01
A new analytical procedure for determination of lanthanides in environmental samples after chemical separation from major matrix elements on DOWEX 50W-X8 resin followed by preconcentration with chelating agent ammonium pyrrolidine dithiocarbamate (APDC) and analyses of thin targets by energy dispersive X-ray fluorescence (EDXRF) method using 109Cd as the source of excitation was presented. Characteristic Lalpha X-ray lines of the lanthanides were used for calculations of the net peak area and mass concentrations. The influence of pH value of the solution and addition of organic matter on the complexation was investigated. Percentage of recovery of each lanthanide after separation on DOWEX 50W-X8 resin was also determined. Accuracy of the method was tested on standard reference materials and real environmental samples (red mud material). ...
A new, simple approach to the determination of trace elements in water
1999-12-01
Full text: The analysis and characterization of drinking and waste water pollutants, which are subject to environmental regulations and control requires the detection of many organic compounds as well as the elemental specification of a wide range of elements. Development of a suitable laboratory method for qualitative and/or quantitative analysis has to include adequate specimen preparation procedures, which allows determination at trace levels. Such a laboratory methods should be simple in practice and cost effective. Wavelength Dispersive X-Ray Fluorescence Spectrometry (WDXRF) was chosen here for trace element detection, as a new technique for analysis at ppb levels. Wavelength Dispersive X-Ray Fluorescence Spectrometry (WDXRF) is a suitable technique for trace element detection corresponding to ppb concentration ranges in clean water and semiconductor chemicals. Obtainable detection limits are better than 9 ppb. The presented method is multi-element, non-destructive and require little sample preparation and repeatability is better than 20%. Copyright (1999) Australian X-ray Analytical Association Inc.
2008-01-01
The X-ray Fluorescence Laboratory is a part of Department of Applied Nuclear Physics at the Faculty of Physics and Applied Computer Science, University of Science and Technology AGH, Krakow, Poland. The XRF laboratory is equipped with the multifunctional energy-dispersive X-ray fluorescence system and micro beam X-ray fluorescence confocal microscope. The multifunctional system consists of micro-beam X-ray fluorescence spectrometer with capillary X-ray optics, the broad X-ray beam from Mo secondary target for XRF analysis of bulk samples and total reflection X-ray technique. Chemical laboratory is equipped with pressure digestion system used for the sample preparation. The X-ray fluorescence microscopy was used for topographic and quantitative elemental analysis of the areas of rat brain that are involved in epileptic activity. Two groups of animals were ...
2008-01-01
Two methods are utilized to correct the influence of the mineralogical effect on the calibration of elements in geological samples when the pressed powder pellet method is used in wavelength dispersive X-ray fluorescence analysis. The first method involves checking of the 2 angle for the analyzed element in each sample to correct peak shift and the second method involves replacing the peak intensity with the peak area of the analytical line, so to correct for any shape distortion of the peak. The results were compared with those obtained from the normal method. Major elements in 27 Chinese Certified Reference Materials (CRMs) of rocks, soils and sediments were calibrated with a linear regression curve without theoretical or empirical coefficients. In view of the K values, the calibration...
The application of XRF to the thickness measurement of paper
2007-01-01
The purpose of this paper is to study on the application of XRF to the thickness measurement of paper. The mass thickness of a number of paper samples were respectively measured by the X-ray absorption method and the primary rays of radiated sources scattering method. The measurement results had been compared with each other, and got several helpful discussions. The measurement was using the IED-2000P type X-ray fluorescence analyzer from Chengdu Micro-Particle Technology Ltd., which is composed of a Si-pin X-ray detector with thermo electrical cooler, and double isotope sources (238Pu). The experiment indicated that the veracity of the X-ray absorption method on the thickness measurement of paper is better than the primary rays of radiated sources scattering method, and the application of the primary rays of radiated sources scattering method to the thickness ...
A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities. (WRF)
A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities. (WRF)
1986-04-01
A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities. (WRF)
Orbital radiation imaging with various physical principles
2001-01-01
This paper describes the characteristics of orbital radiation and authors' investigations on the high spatial resolution X ray-CT, fluorescence X ray-CT and phase-type X ray imaging. Orbital radiation is an X ray generated by relativistic electron bended by magnet in the synchrotron and possesses the high photon density/unit area (
2010-01-01
The paper proposes a simple, accurate, precise, and rapid method for determining the high atomic number (Z) major-element, tantalum (Z = 73), in the rare mineral, columbite ((Fe, Mn) (Nb, Ta)2O6)-tantalite ((Fe, Mn) (Ta, Nb )2O6), by wavelength-dispersive X-ray fluorescence spectrometry (WDXRFS). The other major-element in columbite-tantalite is the lower atomic number niobium (Z = 41). The method uses the characteristic radiation, TaKalpha , and an LiF 420 analysing crystal, to overcome the problems associated with the serious X-ray spectral-Iine interference of the second-order NbKalpha and NbKbeta with the first-order TaLalpha1 and TaLbeta1 respectively. Samples of ...
Latest developments and opportunities for 3D analysis of biological samples by confocal mu-XRF
2010-01-01
X-ray fluorescence analysis performed with a primary radiation focused in the micrometer range is known as micro-X-ray fluorescence (mu-XRF). It is characterized by a penetration depth higher than other micro-analytical methods, reaching hundreds of micrometers in biological samples. This characteristic of the X-ray beam can be employed in 3D analysis. An innovative method to perform 3D analysis by mu-XRF is the so-called confocal setup. The confocal setup consists of X-ray lenses in the excitation as well as in the detection channel. In this configuration, a micro-volume defined by the overlap of the foci of both X-ray lenses is analyzed. Scanning this micro-volume through the sample can be used to perform a study in three dimensions. At present, X-ray lenses used in confocal mu-XRF experiments are mainly glass capillaries and ...
In vivo elemental analysis in occupational medicine using X-ray fluorescence
1986-01-01
A technique for the in vivo determination of cadmium in the kidney cortex using X-ray fluorescence analysis (XRF) has been developed for clinical use. The method uses the Cd K-alfa X-rays. The radiation from the tube was polarized by scattering at 90 degrees in a plastic disc. Using a Si(Li) detector the minimum detectable concentration (MDC) of cadmium in the renal cortex was about 6 ppm for an effective dose equivalent of 3 micro-Sievert. The precision of the method was estimated to be about 23 percent. The clinical usefulness was confirmed by studying 20 occupationally exposed cadmium workers and three controls. The cadmium workers showed levels of cadmium in the kidney in the range 47-317 ppm, and controls showed levels below 30 ppm. Using XRF in vivo large-scale measurements of lead in the fingerbone of more than 100 lead workers were performed. The technique used included two ...
Waste analysis by ED PRFA. Abfallanalytik mit ED PRFA
1992-08-01
Examinations are presented for using energy dispersive X-ray spectroscopy for waste analysis. Sensitivity and precision of ED PXRF-method can be improved by using polarized radiation for excitation of fluorescence. Results of this examinations demonstrate, a fast screening analysis is possible for inhomogenous samples with a very easy sample preparation in trace analysis too. (orig.).
Self-absorption correction factor for a sample excited by the bremsstrahlung radiation
2002-12-01
A method of calculating the self-absorption correction factor for fluorescent X-rays from a sample excited by the bremsstrahlung has been described. As a typical example, the correction factors for K{sub {alpha}} of Si and Cu for different tube voltages have been calculated. Polynomial fit of the correction factor against the tube voltage in the range 10-100 kV has been given for both the elements.
Self-absorption correction factor for a sample excited by the bremsstrahlung radiation
A method of calculating the self-absorption correction factor for fluorescent X-rays from a sample excited by the bremsstrahlung has been described. As a typical example, the correction factors for K subalpha of Si and Cu for different tube voltages have been calculated. Polynomial fit of the correction factor against the tube voltage in the range 10-100 kV has been given for both the elements.
2003-05-15
Energy dispersive X-ray fluorescence analysis of right back leg bone samples taken from adult female rats administered paclitaxel (taxol) was carried out using standard addition method. Because qualitative and quantitative data analysis of rat bone samples is not found in the literature, comparison was not made with other experimental results. Our experimental results are presented and discussed in this study.
Putting synchrotron radiation to work for technology: Analytic methods
This report contains viewgraphs on: Advanced Light Source; Ultra-ESCA: Advanced Capabilities of XPS with High-Brightness Synchrotron Radiation; High-Resolution (20 nm) XPS and XANES with the ALS; Photoelectron Spectroscopy in Industry: Current Capabilities, Needs, and Possible Roles for the ALS; Materials Analysis by Photoemission: Is This Practical at ALS ; Applications of Long-Wavelength X-Ray Fluorescence Spectrometry and X-Ray Powder Diffractometry.
Putting synchrotron radiation to work for technology: Analytic methods
This report contains viewgraphs on: Advanced Light Source; Ultra-ESCA: Advanced Capabilities of XPS with High-Brightness Synchrotron Radiation; High-Resolution (20 nm) XPS and XANES with the ALS; Photoelectron Spectroscopy in Industry: Current Capabilities, Needs, and Possible Roles for the ALS; Materials Analysis by Photoemission: Is This Practical at ALS?; Applications of Long-Wavelength X-Ray Fluorescence Spectrometry and X-Ray Powder Diffractometry.
Micro-distribution patterns of trace elements in Nandan iron meteorite
1992-01-01
The micro-distribution patterns of trace elements in the Nandan iron meteorite are studied by a synchrotron radiation X-ray fluorescence micro-scanning method (SRXRFMS). On the basis of the experimental results the classification, origin, evolution and other aspects are discussed. It seems reasonable that the Nandan iron meteorite should be classified to the group IAB. Further, it might be formed the source matter with the chondritic composition, which experienced the impact and partial melting
1983-01-01
Elements Ti, Mn, Fe, Ni, Cu, Zn, Pb, Br, Rb and Sr were determined by the method of radionuclide X-ray fluorescence analysis with semiconductor detection in samples of Taraxacum officinale from various localities of Bratislava. The dependence of their content on the source and the degree of the air pollution was found out.
1998-01-01
The conditions for the determination of Co, Cr, Fe, Mn, Ni and Pb in plant materials and As, Ba, Fe, Pb, Sr, Rb and Zr in soils by energy dispersive X-ray fluorescence analysis with americium-241, as excitation source are discussed. The applicability of the proposed method is tested by the analysis of certified reference materials and of two plant biomonitors. (author)
Chemical sample preparation during analysis of rare metal industry materials. Review
1981-01-01
The ways of the sample break-down by mineral acids, hydrogen peroxide or their mixtures, by melting with lithium metaborate, potassium pyrosulphate, using the complexing agents with an aid of analytical autoclaves, are generalized. The means of the break-down of objects, containing rare elements for subsequent studies using the methods of atomic adsorption spectroscopy, inductance binding plasma, X-ray fluorescence analysis, are reduced in a table.
2003-01-01
A procedure has been implemented for multielemental analysis of alloys using a nondestructive method. The method is based on the direct bombing of the sample with a beam of gamma photons from Am-241 source, and by the evaluation the spectrum obtained, the present elements are identified and quantifies. For the evaluation the spectrum, the software Quantitative X- Ray Analysis System (QXAS) version 3.5, and elemental sensitivities method, provided by the IAEA was used. The method is applicable to alloys of Au, Ag, Cu, Ni, Zn, Pd, etc. in concentrations the order % with an error of +- 5% It can to be used as the quality control of jewels. (author)
1976-01-01
The principles of gamma methods of nuclear geophysics, much used in recent years in the exploration for and development of ore deposits, are discussed. The classification, physical principles, and theory of gamma methods are examined. The construction principles of analyzing devices, the methods of achieving and conditions for using each of the methods, and the ways of processing and interpreting the data are analyzed. The optimum measurement conditions and methods of analyzing powdered rocks, well logging techniques, and rock sampling methods are discussed.
Website Policies and Important Links Comments
 |
 |
 |
WorldWideScience.org is maintained by the
U.S. Department of Energy's
Office of Scientific and Technical Information as the Operating Agent
for the WorldWideScience Alliance.