X-Ray Spectrometry

Current research reports and chronological list of recent articles.

The international scientifc journal X-Ray Spectrometry is devoted to the rapid publication of papers dealing with the theory and application of x-ray spectrometry using electron, x-ray photon, proton, gamma and gamma-x sources. Covering advances in techniques, methods and equipment, this established journal provides the ideal platform for the discussion of more sophisticated X-ray analytical methods.

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Additional research articles see Current Chemistry Research Articles. Magazines with similar content (spectroscopy):

 - Analytical Chemistry.

 - Journal of Analytical Atomic Spectrometry.

X-Ray Spectrometry - Abstracts

Utilization of nondestructive techniques for analysis of the Martian meteorite NWA 6963 and its implications for astrobiology

Martian meteorites are excellent study materials for understanding the present and past of Mars, as they are important historical astrophysical artifacts because they possess information about Martian geological evolution and physical and chemical characteristics. In our case, we analyzed the NWA 6963 Martian meteorite classified as basaltic shergottite because of its chemical structure. A computerized microtomography (μCT) study in the NWA 6963 Martian meteorite provided us with 2D and 3D images that were extremely useful for ascertaining the internal structure of the analyzed sample and gave us the opportunity to find a crumpled material with a very peculiar structural format. In addition, it was possible to observe through the μCT that this encrusted material also has a completely different density of the meteorite. Calcium, strontium, and potassium were detected qualitatively, among others through the technique of X-ray fluorescence.
Datum: 25.09.2017

Size-resolved analysis of fine and ultrafine fractions of indoor particulate matter using energy dispersive X-ray fluorescence and electron microscopy

We used a multistage PIXE inertial impactor with nine different aerodynamic diameter ranges (between 16 and 0.06 μm) to sample indoor particulate matter (PM). X-ray fluorescence (XRF) measurements performed at cutoff diameters (CoDs) of 0.25, 0.5, 1, 2, 4, and 8 μm were used to identify elements in various size fractions. Anthropogenic sources were the dominant sources for fine and ultrafine particle sizes. The XRF results show that natural sources also contribute to the fine and ultrafine fractions of pollutants. Scanning electron microscopy and energy-dispersive system analysis were performed on membranes having PM CoDs of 4, 2, 1, 0.5, and 0.25 μm. Elemental mappings show the membranes with PM of CoDs 0.25 and 0.5 μm having S as a dominant element, confirming the results obtained with XRF. Strong correlation among maps of S, N, and O show that ammonium sulfate is the major constituent at these size fractions. Other elements such as Si, Ca, Fe, Al, and Mg show up in smaller amounts at these size fractions but increase for membranes with larger particles. For size fractions larger than 0.5 μm, there is a good correlation between the elemental maps of these elements and oxygen, indicating that these elements exist mostly in oxide forms. The absence of clear N signals and the correlation between the Ca and S maps indicate that S in these size fractions is not due to ammonium sulfate. The presence of Mg, K, Cl, and Na at these CoDs shows that these elements are due to salts originating from sea breeze.
Datum: 22.09.2017

An upgraded external beam PIXE setup for multielemental analysis of atmospheric aerosol samples

The external beam particle-induced X-ray emission (PIXE) setup has been upgraded by introducing a new silicon drift detector with the aim of obtaining better minimum detection limits (MDLs) at the 2 × 1.7 MV Tandetron accelerator of the Beijing Normal University in China. The upgraded external beam PIXE setup is equipped with two silicon drift detectors for PIXE analysis of low and high Z elements. A surface barrier detector for Rutherford backscattering spectrometry monitors beam and helium flow. Two kinds of aerosol filter samples (quartz fiber filters and Teflon filters) were studied. A 200-μm thick Mylar absorber in front of the medium-high energy X-rays detector was adopted, and it got the best MDLs for atmospheric aerosol samples analysis. Multielemental analysis of quartz fiber filter aerosol samples was achieved. For more accurate and better MDLs of low Z elements in PIXE analysis, it is necessary to keep sufficient helium flow behind the thin samples.
Datum: 15.09.2017

Study of gamma/X-ray interaction in Kondo insulators

We have studied the gamma/X-ray interaction parameters such as mass attenuation coefficient, mean free path (λ), half value layer, 10th value layer, energy-absorption buildup factors, and variation of electrical conductivity with the energy of gamma/X-ray between 1 keV and 100 GeV for Kondo insulators such as FeSi, Ce3Bi4Pt3, SmB6, YbB12, CeNiSn, CeRhSb, CeRuSn, and CeFeP. The variation of photon interaction parameters with incident energy of gamma/X-ray is graphically represented. We have also identified the X-ray absorption edges for the Kondo insulators. This identified X-ray absorption edges are useful in the characterizing of Kondo insulators such as FeSi, Ce3Bi4Pt3, SmB6, YbB12, CeNiSn, CeRhSb, CeRuSn, and CeFeP. Hence, these data are also useful in the material science. This type of data for Kondo insulators is not available in literature. Hence, this work is first of its kind, and it is useful in various fields of nuclear physics.
Datum: 15.09.2017

High concentration measurements of U and Pu with nondestructive and standardless K-edge densitometer device

In nuclear activities such as reprocessing plants, safeguard laboratories, or research centers, U and Pu are regularly analyzed. Fast and accurate analytical devices are favored such as K-edge densitometer. This paper presents the results obtained by this device from assay samples with high U and Pu concentrations. Two processing methods without calibration (except energy calibration) are compared and discussed. Despite literature advising against the use of estimated mass attenuation coefficients for near edge energy, this study shows that these values can contribute to very good results for uranium and plutonium concentration estimations, with a bias less than 1%.
Datum: 14.09.2017

Pigments characterization of polychrome vases production at Lipára: New insights by noninvasive spectroscopic methods

One of the most impressive Sicilian pottery production is attributed to the so-called Lipari Painter and his followers, whose vessels—found in the archeological site of Lipari (Aeolian Island, Sicily)—are decorated with characteristic blue, red, and white figures. From the archeological point of view, these artworks keep open many questions concerning dating, production technique, and cultural background. In this context, new data on the manufacture procedures and on the raw materials used for the pigments may contribute to a deeper comprehension of this early Hellenistic vase tradition. The preciousness of the vessels, exhibited at the Archeological Museum of Lipari, imposed the use of in situ nondestructive methods to address new insights on the nature of the colored layers. Thus, analyses by Raman and X-ray fluorescence spectroscopy have been performed with portable instruments on a selection of vessels certainly attributed to Lipari Painter and to some others of his followers. The results of this study testify the use of different pigments: kaolin and gypsum, probably supplied locally, for white layers; Egyptian blue for blue hues; red ochre for brown-reddish hues; and cinnabar for pink and red-purple nuances. The identification of both Egyptian blue and cinnabar opens an interesting discussion about dating and circulation of the raw materials.
Datum: 11.09.2017

A sample carrier for measuring discrete powdered samples with an ITRAX XRF core scanner

The elemental composition of discrete powdered sediment samples can be measured by the energy-dispersive X-ray fluorescence (XRF) system that is installed in XRF core scanners. Because an appropriate sample carrier for powdered samples is currently not available, for example, for the ITRAX XRF core scanner, such a carrier is presented in this technical note. The designed sample carrier can hold 30 sample cups with a volume of 0.88 cm3 each. A maximum of 5 sample carriers, that is, 150 samples, can be measured in one run. The sample cups and carriers are optimized for a measurement procedure with a step size of 5 mm and variable count times up to 100 s per sample. With this setting, data are collected from an area of 100 mm2 in the center of the sample thereby ensuring a good representativeness of the signal because potential sample inhomogeneity is accounted for. Because the described sample carrier system allows rapid element analyses of discrete powdered environmental samples with an XRF core scanner, it may in some cases represent a time- and cost-efficient alternative to conventional XRF analyses.
Datum: 11.09.2017

Determination of effective atomic numbers and mass attenuation coefficients of samples using in-situ energy-dispersive X-ray fluorescence analysis

The matrix effect has a major impact on energy-dispersive X-ray fluorescence analysis (EDXRFA) and is difficult to be evaluated due to that the contents of some low-atomic-number elements cannot be identified by in-situ EDXRFA. Up to today, the fundamental parameter algorithm proposed by Rousseau has been widely applied to correct the matrix effect. Accordingly, determining the matrix and mass attenuation coefficient (μ/ρ) of sample is a key issue for the fundamental parameter algorithm. In present work, the method to deduce μ/ρ by effective atomic number (Zeff) was studied. First, the relationship between Zeff and coherence to Compton scatting ratio (R) of the incident X-ray was determined by standard samples. Then, we deduce Zeff and their μ/ρ. The value of μ/ρ deduced by our method is in good agreement with that calculated by WinXCOM, and the relative change (Δ) is less than 7%. We also deduced Zeff and their μ/ρ of Chinese national standard soil samples employing our method and good agreement with the calculated values were also obtained. We found that the agreement between experimental values of μ/ρ with theoretical values by WinXCOM still exists when the energy of the incident X-ray is greater than 4 keV, and the Δ is less than 10%. The result indicates that our method may be applied directly to in-situ EDXRFA.
Datum: 24.08.2017

Characterization of ashes from greenhouse crops plant biomass residues using X-ray fluorescence analysis and X-ray diffraction

A characterization of ashes obtained by thermal treatments on greenhouse crops plant biomass residues is presented. The chemical analysis, by X-ray fluorescence (wavelength-dispersive X-ray fluorescence), and phase analysis, by X-ray diffraction, of the resultant ashes are reported. Thermal treatments of selected samples of these residues increase the relative amounts of inorganic Mg, Si, P, and S in the ashes, being these amounts as high as increasing temperature. As an opposite effect, Na, Cl, and K contents decrease as increasing temperature by a volatilization process of the chlorides, as confirmed by X-ray diffraction. The crystalline phase analysis of the ashes demonstrates the formation of inorganic constituents of the biomass, including alkaline chlorides and calcium salts (calcite, anhydrite, and apatite). Progressive thermal treatments induce the formation of new silicate phases (akermanite and grossularite) and silica (α-quartz and cristobalite). Furthermore, the particle size of the starting biomass samples does not influence the evolution of the crystalline phases by thermal treatments. In contrast, a previous leaching using water and subsequent heating at 1,000 °C produces the formation of periclase (MgO), lime (CaO), and the silicate gehlenite, without the presence of anhydrite. This study is interesting for future investigations on the residues as a profitable biomass source for energy production and sustainable large-scale management. Some potential applications of the resultant ashes can be proposed.
Datum: 18.08.2017

Issue Information

No abstract is available for this article.
Datum: 17.08.2017

Synchrotron radiation induced X-ray production cross sections of 66Dy at energies across its Li (i = 1–3) subshell absorption edges

The X-ray production (XRP) cross sections for the 66Dy Lk (k = l, α, η, β2,6,7,15, β1,6, β1,3,4,6, β2,7,15, γ1,5, γ2,3) emission lines have been measured by tuning the incident synchrotron radiation at energies over the range 7.8–9.2 keV and ~10–370 eV above the respective Li (i = 1–3) absorption edges. These measurements aim to check the reliability of the independent particle approximation models used to generate the theoretical data sets of different physical parameters required to calculate the XRP cross sections and also investigate the influence of many body effects on the photoionization process. The measured values have been compared with 4 sets of XRP cross sections calculated using the Dirac–Fock model-based X-ray emission rates, 2 sets of the Li (i = 1–3) subshell photoionization cross sections deduced from the self-consistent Dirac–Hartree–Fock model-based values and the nonrelativistic Hartree–Fock–Slater model-based values, and 2 sets of the fluorescence (ωi) and Coster–Kronig (fij) yields. The present measured Lγ2,3 (originating from decay of the L1 subshell vacancies) XRP cross sections are found to be significantly higher than different sets of theoretical values, whereas a good agreement is generally observed for the various other XRP cross sections and relative intensities.
Datum: 04.08.2017

Mercury in archeological hair samples from Xiongnu burials (Noin-Ula, Mongolia): SR XRF and CXRM analysis

A technique has been developed for determining mercury content in the concentration range of 1–1000 μg/g in hair samples by X-ray fluorescence analysis using synchrotron radiation (synchrotron radiation X-ray fluorescence, Siberian Synchrotron and Terahertz Radiation Center, Budker Institute of Nuclear Physics SB RAS). The mercury content was identified in archeological hair samples from an ancient burial of Xiongnu nobility (Mongolia, mound 22, 1st century BC–1st century AD); the content values were elevated (up to 1100 μg/g) in all the samples (n = 41). An X-ray microanalysis using polycapillary lenses in a confocal scheme (confocal X-ray microscopy station) was developed at the Synchrotron radiation X-ray fluorescence to establish mercury distribution in a cross section of hair shaft with a spatial resolution of 5 μm. The findings of the study make it possible to assume exogenous income of mercury (from the burial environment) to the hair.
Datum: 27.07.2017

Polychromatic simultaneous WDXRF for chemical state analysis using laboratory X-ray source

The authors have started the development of a new scanning-free, wavelength-dispersive X-ray fluorescence spectrometer, which uses a silicon strip detector instead of a goniometer, a slit, flat analyzing crystal, and laboratory X-ray source. The X-rays dispersed by the slit and flat analyzing crystal are detected simultaneously by different silicon strip detector channels, and a high energy resolution is achieved by limiting the measurement range. In the spectrometer designed for Cr, Mn, and Fe in the range from 5.38 to 6.64 keV, an energy resolution of 3.9 eV for Fe Kα1 was obtained, and it was observed that KMnO4 (VII) is different from MnO (II) in the peak energy of Mn Kβ1,3. Furthermore, a Kβ' satellite peak on the low-energy side of Mn Kβ1,3 was clearly observed, and the difference in behavior of Kβ' was investigated. Another similar investigation of Cr2O3 (III) and K2CrO4 (VI) was performed. These results indicate that the new wavelength-dispersive X-ray fluorescence spectrometer has a high energy resolution and is applicable to the chemical state analysis of 3d transition elements, which is obtained by analyzing the details of the Kβ peak at the scale of a few eV. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 20.07.2017

Development of an energy-dispersive X-ray spectroscopy analyzer employing superconducting tunnel junction array detectors toward nanometer-scale elemental mapping

Energy-dispersive X-ray detectors based on superconducting tunnel junctions (STJs) exhibit at best energy resolution of about 5 eV in full width at half-maximum for soft X-rays with energy levels of less than ~1 keV as well as a large sensitive area (>1 mm2) and a high counting rate capability (>500 kcps). We have developed an energy-dispersive X-ray spectroscopy analyzer combined with a scanning electron microscope and STJs to realize elemental mapping with high energy-resolving power. To improve the collection efficiency of the fluorescence X-rays, a polycapillary collimating X-ray lens was installed in the analyzer. The overall system efficiency of the analyzer was more than 1 × 10−4 sr in the soft X-ray range. Its counting rate performance for the N-Kα line was 9.4 cps/nA, near that of setups comprising an electron probe microanalyzer and wavelength-dispersive X-ray spectrometers (WDSs). By improving the X-ray optics, the counting rate is expected to be increased more than 600-fold. The energy resolution of the developed analyzer was assessed according to the full width at half-maximum of the N-Kα peak, which was measured to be 10 eV, indicating an energy resolution about 7 times better than that of conventional X-ray spectroscopy analyzers employing silicon drift detectors (SDDs). These results indicate that the improved analyzer employing STJs can realize both the high throughputs of SDDs and the high energy resolution of WDSs. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 18.07.2017

The energy dispersive scheme of X-ray fluorescence analysis with a crystal polarizer and polycapillary optics

The efficiency of the polarization scheme based on polycapillary optics and a diamond crystal polarizer was demonstrated. The scheme provides suppression of the background of scattered radiation in measuring X-ray fluorescence spectra. A quasi-parallel X-ray beam with an angular divergence of 4.2 mrad was formed by a microfocus source with a copper anode and polycapillary half-lens. Simultaneous polarization and monochromatization of radiation was obtained with a crystal of natural diamond, which was set at the diffraction reflection (113). The degree of polarization of CuKα1 spectral line and the maximum radiation flux were respectively equal to 99.86% and 5 · 106 photon/s. In the direction orthogonal to the plane of diffraction, the maximum attenuation of the background was up to 19 dB.
Datum: 12.07.2017

Novel sample treatment procedures for the determination of phosphorus in Cu-based alloys using X-ray fluorescence spectrometry to solve the microstructural effect issue

The accurate analysis of hard CuP and CuPAg-type solders using X-ray fluorescence spectrometry is a difficult task. Surface milling, the most common sample preparation method for calibration materials, results in poor accuracy for the phosphorus analysis, as evidenced by the unacceptable values of the root mean square error. Meanwhile, the analysis of real samples provides incorrect results, and microstructural effects are the main source of error. Thus, this effect was negated by considering the information depth of the phosphorus Kα line and the microstructure size of the alloys. Phosphorus was measured using a thin layer of the sample (a thickness of several micrometers). As a result, the analyzed layer was a poor representative of the sample. Two different approaches for solving the microstructural effect issue were proposed. In the first method, the alloy was remelted under controlled conditions to obtain fine-grain samples, which successfully limited the microstructural effects. The second solution used specially prepared thin layer samples, and the sample dissolution eliminated the microstructural effect. Using the developed sample treatment methods resulted in an improvement in the accuracy of the phosphorus calibration curves. This allowed for the correct determination of phosphorus and other alloying elements in the Cu-based alloys with low uncertainties.
Datum: 12.07.2017

PIXE-based detection of elemental accumulation during direct organogenesis in Blepharispermum subsessile DC.: An endangered medicinal plant of Odisha, India

Particle-induced X-ray emission was used to investigate mineral accumulation during different developmental stages of direct organogenesis from cotyledon explants of Blepharispermum subsessile beginning from shoot bud initiation and formation to in vitro regenerated roots. Mineral uptake and accumulation appeared selective and varied between different stages of shoot bud initiation and formation (Stage 1), proliferation of leafy shoots (Stage 2), and in vitro regenerated roots (Stage 3). The concentrations of 2 macro elements, K and Ca, were found in higher quantity during proliferation of shoot buds to leafy shoots stage suggesting their role in cell division, bud formation, and multiplication of the plant. Most of the micronutrients such as Mn, Fe, Ni, Cu, and Zn were found to be accumulated in higher quantities in in vitro regenerated roots, as they provide the plant with a larger surface area and hence a greater potential for mineral uptake. The results of particle-induced X-ray emission test suggest that the information on the accumulation of elements during developmental stages in vitro could be useful for formulating a media for the induction of high-frequency regeneration of in this important endangered medicinal plant species for its ex situ conservation.
Datum: 10.07.2017

Zinc distribution in human prostate carcinoma cell line using synchrotron X-ray microfluorescence

Cancer is a worldwide public health problem, and its incidence in the world grew by 20% in the last decade. Zinc, an essential trace element, is involved in many cellular processes. Concerning prostate cancer, Zn could inhibit the growth of tumor cells, by inducing cell cycle arrest or apoptosis. X-ray microfluorescence (μXRF) is an elemental analysis technique that allows mapping biologically important elements at a submillimeter scale, with high sensitivity and negligible damage to the sample. In this study, we investigated cell viability through colorimetric cytotoxicity assay (MTT) and the behavior of human prostate cell lines obtained from normal (RWPE-1) and tumorigenic (DU145) epithelium, in three-dimensional spheroid cultures after supplementation with ZnCl2 for 24 and 48 hr using synchrotron μXRF. The measurements were performed at the Synchrotron Light National Laboratory (Campinas, Brazil). The results of μXRF showed that Zn intensity decreased in the DU145 tumor cells independent of supplementation or treatment time, and in normal cells, the intensity increased with supplementation and treatment time. The MTT assay results showed no significant differences, which indicates that the cell viability did not change. Our results indicate that μXRF can be used as an important tool to understand the mechanism of the loss of ability to capture zinc by prostate cancer cells. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 10.07.2017

Improved approach for the determination of low-Z elements in uranium samples using a vacuum chamber TXRF spectrometer

Total reflection X-ray fluorescence (TXRF) method for the determination of low atomic number (Z) elements Na (Z = 11) to Ca (Z = 20) using Cr Kα excitation, vacuum atmosphere sample chamber, and ultrathin window detector of a low Z–high Z TXRF spectrometer has been developed. The earlier reported problem in determination of Al, due to interference of U Mα escape peak with Al Kα, was taken care by more intense solvent extraction-based separation of uranium matrix from the sample solutions. Any dissolved tri-n-butyl phosphate having traces of uranium left after solvent extraction was removed from the sample solutions by equilibrating with n-dodecane. This approach resulted in the betterment of analytical results. The method developed was validated by analyzing three  Certified Reference Materials for trace metals in uranium oxide, developed by Department of Atomic Energy, Government of India. The TXRF determined results were found to have an average precision of 8.0% (1σ, n = 3) and the average deviation of the TXRF determined values from the certified concentrations was 7.3%. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 06.07.2017

Archeological ceramic artifacts characterization through computed microtomography and X-ray fluorescence

The analysis of ceramic materials has been proven to be an indispensable tool for indirectly approaching past people and societies through their cultural remnants, allowing inferences about their technology, and their interaction with their surrounding physical and social environments. Pottery products acquire their characteristic properties during the manufacture process. Compositional (mineralogical and chemical) and microstructural analyses have become an integral part of interdisciplinary archaeological research, underlining the importance of compositional and technological comparative studies. As damages must be avoided to the archeological artifacts under study, nondestructivity is an essential requirement for the scientific methods operating in this research field. Therefore, the aim of this publication is to correlate 2 nondestructive techniques, namely, computed microtomography and X-ray microfluorescence in the structural characterization and investigation of the elemental composition of ceramic samples from 2 different Brazilian archaeological sites. Computed microtomography allowed to differentiate the various materials with different densities that compose the samples. These materials had their elemental composition revealed by X-ray microfluorescence technique, where several tempers used during the manufacturing process were identified. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 29.06.2017

Optimization of L-shell X-ray fluorescence detection of lead in bone phantoms using synchrotron radiation

Closely related toxicity and retention mechanisms of lead (Pb) in the human body involve the bone tissues where Pb can accumulate and reside on a time scale ranging from years to tens of years. In vivo measurements of bone Pb can, therefore, play an important role in a comprehensive health risk assessment of Pb exposure. In vivo L-shell X-ray fluorescence (LXRF) measurement of bone Pb was first demonstrated over 4 decades ago. Implementation of the method, however, encountered challenges associated with low sensitivity and calibration procedure. In this study, the LXRF measurement was optimized by varying the incident photon energy and the excitation-detection geometry. The Canadian Light Source synchrotron radiation was used to compare 2 different excitation-detection geometries of 90° and 135° using 3 different X-ray photon energies: 15.8, 16.6, and 17.5 keV. These energies optimized excitation of the L3 subshell of Pb and simulated the most intense K-shell emissions of zirconium, niobium, and molybdenum, respectively. Five rectangular plaster-of-Paris bone phantoms with Pb concentrations of 0, 7, 17, 26, and 34 μg/g, and one rectangular 3.1-mm-thick resin phantom mimicked the X-ray attenuation properties of human bone and soft tissue, respectively. Optimal LXRF detection was obtained by the 15.8-keV energy and the 90° and 135° geometries for the bare bone and the bone and soft tissue phantoms, respectively.
Datum: 29.06.2017

The comparative verification of calibration curve and background fundamental parameter methods for impurity analysis in drug materials

The United States Pharmacopeia (USP) has established general analysis guidelines of X-Ray fluorescence (XRF) methodology in chapter <735>, XRF spectrometry. Meanwhile, the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH Q3D) guideline, presenting a policy for limiting 24 elements such as Cd, Pb, and As in drug products and pharmaceutical ingredients, has now reached Step 5 (Implementation). The limit values of ICH Q3D are strict, for example, near or less than 1 μg/g for Cd and Pb. Moreover, there are other difficulties for accurate analysis, such as different types of matrices and the very small sample volumes in the synthesis research process for new product development in the pharmaceutical industries. Energy dispersive XRF can correct the influence of various matrices and volumes and also has the advantages of nonchemical pretreatment and nondestructive analysis. Advancements in the quantitation by fundamental parameters (FP) method using theoretical calculations, background (BG)-FP method, leads to reduction in the number of standard samples and effectiveness on the practical elemental impurity control in pharmaceutical researches and inspections. In order to show the applicability of using the BG-FP method, in this study, the quantitative values of some hazardous inorganic impurities for Cd, Pb, As, V, Co, and Ni in a cellulose matrix were compared by calibration curve method and BG-FP method through the verification of USP <735>. Both methods can meet the acceptance criteria for accuracy and precision in USP <735>. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 29.06.2017

Data quantification procedures for a bench-top elemental microimaging of brain specimens for the clinical studies on the obesity treatment by transcranial direct current brain stimulation

A decision on how to choose the appropriate data quantification procedure lies behind the most serious methodological challenges in microbeam X-ray fluorescence imaging of tissue slices. This problem becomes particularly cumbersome whenever intermediate thickness samples must be utilized in order to increase the signal to noise ratio. Noteworthy, it is always the case when laboratory-based X-ray sources are used, which arises from their relatively limited beam flux. In our study, we put particular attention to the quantitative elemental microanalysis of dried brain tissue samples taken from the obese rats treated by the transcranial direct current stimulation. For doing so, we took advantage of tissue probing by an X-ray microscope system for accessing P, S, Cl, K, Ca, Fe, Cu, and Zn in the brain structures triggering food intake and appetite regulation. Proper data quantification schemes are presented by showing the elements whereby the radiation loss by self-absorption of fluorescence radiation is negligible. The impact of sample self-absorption correction on quantitative data is studied for the brain structures with various water fraction spanning from 75–83%. It is demonstrated that K, Ca, Fe, Cu, and Zn can effectively be quantified by the thin-sample approach, regardless sample matrix. Quantitative results demonstrate that the clinical efficacy of transcranial direct current stimulation is linked to significant changes in surface masses of elements triggering brain membrane currents: K, Cl, and also, those defining the redox state: Fe in the hunger center. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 28.06.2017

Improved Rayleigh to Compton scattering ratio curves for mass attenuation coefficients determination for X-ray fluorescence analysis

Nondestructive assays are essentials for certain types of sample materials, and, among those, the X-ray fluorescence technique enables the determinations of stable elements, and there is an increasing effort on the development of equipment to suit the various needs. Nevertheless, a great difficulty on the analysis of unknown materials' composition is to account for self-absorption of the fluorescence photons that must be considered in the elemental concentration calculation. The correlation between the Rayleigh to Compton scattering ratio to the mass attenuation coefficient has proved to follow a single polynomial function for the first 20 elements of the periodical table with a correlation factor higher than of 0.998 for the sixth order function. The Rayleigh to Compton scattering ratios for pure elements and the 22.16 keV photons, the main energy from an X-ray tube with silver anode, were determined with the MCNP6 Monte Carlo computer code. Two scattering angles were considered. Reference samples were measured, and the calculated results were compared to the literature values of the mass attenuation coefficient for some known samples and showed to be within 20% for de 90° scattering angle. Only Lucite was slightly above 20%. Curve fit coefficients are also presented for the 7.11- and 17.40-keV photon energies.
Datum: 22.06.2017

A new micro X-ray fluorescence spectrometer for in vivo elemental analysis in plants

In vivo micro X-ray fluorescence (micro-XRF) on plants is aimed at mapping spatial ion accumulation, eg. in plant leaves to minimize artifacts arising from sample preparation and to be able to detect changes occurring under environmental stress. To obtain reliable results, a spectrometer and sample setup that maintain the plant in good physiological condition are necessary. We have built a micro-XRF spectrometer, in which analyses are performed in air, thereby allowing for in vivo micro-XRF measurements in plants. Mapping is performed with full spectrum acquisition in each pixel and is automated and controlled by computer software developed for this micro-XRF unit. Limits of detection were found to be comparable to those found previously at second-generation synchrotron facilities using a freestanding film reference from 0.04 ng/mm2 for Fe to 0.20 ng/mm2 for Pb. The spot size was determined to be less than 14 μm at Rh Kα line (20.214 keV). Relative sensitivities were determined for elements from S to Pb using the freestanding film reference and a 13-element standard dried droplet deposition. For in vivo measurements, a dedicated sample holder was developed by 3-D printing. Here, we present the in vivo elemental analysis capabilities of our micro-XRF spectrometer by mapping elements in Arabidopsis thaliana plants and by assessing their physiological state before and after scanning. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 16.06.2017

Quantitative speciation of manganese oxide mixtures by RIXS/RRS spectroscopy

Resonant inelastic X-ray scattering, also named X-ray resonant Raman scattering, was recently used to discriminate local chemical environments. By means of this novel technique, the speciation of samples could be attained in a variety of samples and experimental conditions. Until now, this discrimination methodology had been applied only to pure compounds, being the speciation possible by two different mathematical treatments. Nevertheless, the effectiveness/sensitivity of this technique has not been tested yet in samples containing mixtures of oxides of the same element. In this work, the first results of quantitative speciation of mixtures of manganese compounds, using resonant inelastic X-ray scattering/X-ray resonant Raman scattering spectroscopy, are presented. The results show that it is possible to discriminate and quantify oxide mixtures of the same element in slightly different proportions, allowing a quantitative speciation of compound mixtures in a variety of experimental conditions, presenting also several advantages over conventional spectroscopic techniques. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 13.06.2017

Evaluation of metal release from battery and electronic components in soil using SR-TXRF and EDXRF

Potentially toxic elements may be leached contaminating the soil, surface, and ground water due to the improper disposal of batteries and electronic devices. The objective of this study was to evaluate metal release from batteries and electronic components deposited in specific receptacles filled with soil in which acid rain was simulated. The leachate solution and the soil were analyzed by synchrotron radiation total reflection x-ray fluorescence and benchtop energy dispersive x-ray fluorescence, respectively. Results indicate that batteries released K, Mn, Fe, Cu, Zn, and Pb and electronic component released Ti, Mn, Fe, Cu, Zn, and Pb. For batteries' leachate test samples, higher amounts of Fe, Cu, Mn, Zn, and Pb have been released compared with electronic component ones under same the experimental conditions. The Fe, Cu, and Pb concentrations in battery leachate test samples were above their National Environment Council maximum permitted values (MPV) and in the electronic waste leachate ones, only the Pb concentrations was above MPV. For soil sample containing batteries K, Mn and Zn presented higher concentrations, mainly at the 10-cm topsoil, ranging from 0.16 to 0.50, 0.27 to 8.67, and 0.03 to 1.26, in % (% w/w), respectively. The Zn–C battery soil samples present similar behavior to the alkaline ones. The impact due to the Pb release was higher in the soil test samples with electronic components, in which their concentrations ranged from 51 to 394 mg/kg, above its MPV up to 28-cm soil layer. The X-ray fluorescence techniques employed were suitable for water and soil environmental evaluation.
Datum: 07.06.2017

Application of TXRF and XRPD techniques for analysis of elemental and chemical composition of human kidney stones

Total reflection X-ray fluorescence analysis and X-ray powder diffraction were used for elemental and chemical composition analysis of 83 samples of human kidney stones. Samples came from patients after surgical removal of stones. Elements such as P, K, Ca, Fe, Zn, Ni, Br, Sr, and Pb were determined in all samples. Other elements Mg, S, Cl, Ti, V, Cr, Mn, Cu, Se, Rb, I, and Bi were found in some of the analyzed kidney stones (censoring effect). Descriptive statistics were calculated for all elements paying particular attention to the censored elements. From diffraction measurements, the following crystalline substances were determined in the stones: apatite, struvite, uric acid, weddellite, whewellite, magnesium phosphate, and calcium phosphate. Information of chemical composition was applied to classify the analyzed kidney stone into four groups. Statistical analysis of the results included multigroups comparison, testing of element concentration distribution, and elemental correlations in the dependence of kind of kidney stones. The presented studies are part of wider microbiological studies focusing on the correlation between different kinds of bacteria and fungi presented in the samples of kidney stones and their elemental as well as chemical composition. Information on stone composition can be helpful in understanding kidney stone formation and complemented by additional metabolic blood and urine tests. This, in turn, can lead to appropriate medical treatment together with the reduction of the risk as regards forming new stones.
Datum: 07.06.2017

Evaluation of the X-ray distribution of a syringe-needle type proton-induced X-ray source by Geant4 simulation

The accelerator-based syringe needle-type proton-induced X-ray source, which was proposed by the authors in 2013 as an alternative for prostate cancer brachytherapy, has an essential issue in that its dose distribution is affected by many factors, such as the structure of the needle and incident proton beam conditions. In this paper, as a method of evaluating dose distribution, we propose a Geant4 simulation to study the effect of the incident proton beam condition on the spectrum and distribution of X-ray emission, using experimentally measured proton beam emittance as input data. The results showed that the effect of beam misalignment was significant and confirmed the effectiveness of this method. It is expected that improving this method will clarify the other factors that affect X-ray distribution, so that finally, we can optimize such factors in designing a special dose distribution for the irradiation of tumors of arbitrary size and shape in the tissue. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 07.06.2017

Confocal macro X-ray fluorescence spectrometer on commercial 3D printer

Novel confocal X-ray fluorescence (XRF) spectrometer was designed and constructed for 3D analysis of elementary composition in the surface layer of spatially extended objects having unlimited chemical composition and geometrical shape. The main elements of the XRF device were mounted on a moving frame of a commercial 3D printer. The XRF unit consists of a silicon drift detector and a low-power transmission-type X-ray tube. Both the excitation and secondary X-ray beams were formed and regulated by simple collimator systems in order to create a macro confocal measuring setup. The spatial accuracy of the mechanical stages of the 3D printer achieved was less than 5 μm at 100-μm step-size. The diameter of the focal spot of the confocal measuring arrangement was between 1.5 and 2.0 mm. The alignment of the excitation and secondary X-ray beams and the selection of the measuring spot on the sample surface were ensured by two laser beams and a digital microscope for visualization of the irradiated spot. The elements of the optical system together with the XRF spectrometer were mounted on the horizontal arm of the 3D printer, which mechanical design is capable of synchronized moving the full spectroscopic device within vertical directions. Analytical capability and the 3D spatial resolution of the confocal spectrometer were determined. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 31.05.2017

Probing nanostructured materials using X-ray fluorescence analysis

Dispersion of metal nanoparticles on flat surfaces has attracted considerable interest in many technological applications. Numerous advantages of functionalized patterned nanostructures especially in medical physics, chemistry, biology, and semiconductor quantum dot applications have rapidly driven the growth of this field in the last two decades. In particular, for applications involving biomedical imaging, the nanoparticles have attracted perhaps the greatest attention as these materials provide a direct interface at the subcellular length scale. Reliable characterization methods are thus often needed to infer their detailed structural properties such as average particle size, particle shape, internal structure, surface morphology, distribution of particles, and their chemical composition. As a nondestructive probe, X-ray fluorescence measurements at grazing incidence provide sensitive information about the physical and chemical nature of the nanoparticles over the large surface area of a substrate. Herein, we demonstrate the potential capabilities of the X-ray fluorescence technique for reliable and precise determination of surface morphology of metal nanoparticles, dispersed on a flat surface. Our results show that X-ray standing wave assisted fluorescence measurements are markedly sensitive to the nature of dispersion of nanoparticles on a substrate surface. We have analyzed different types of nanostructured materials; e.g. a W thin film structure and Au nanoparticles deposited on a Si surface. The average size of the Au nanoparticles estimated, using X-ray standing wave fluorescence analysis, was found to closely agree with the atomic force microscopy measurements. The inherent features of the X-ray fluorescence technique permit us to analyze distribution of all kinds of metal and metalloid nanoparticles on a flat surface. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 18.05.2017

Synchrotron XANES and ED-XRF analyses of fine-paste ware from 13th to 14th century maritime Southeast Asia

The combination of energy dispersive X-ray fluorescence (ED-XRF) and synchrotron X-ray absorption near-edge structure (XANES) provides the detailed composition of fine-paste ware (FPW) kendis, dated back to 13th–14th century maritime Southeast Asia. Sources of clay and production sites were classified according to Al2O3, SiO2, α-Fe2O3 and γ-Fe2O3 as well as trace elements. The similarities based on these components provided another evidence of a trade route between Kota Cina in North Sumatra of Indonesia and Kok Moh on Satingphra Peninsula, a well-known production area in present-day Thailand. In additions, the uniquely large contribution of α-Fe2O3 in XANES spectra suggests that Nakhon Si Thammarat province of Thailand could also be one of FPW production areas in maritime Southeast Asia. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 17.05.2017

A device for X-Ray elemental mapping using annular radioisotope source

An energy-dispersive system is described for elemental mapping by X-ray fluorescence spectrometry. The present study describes the design of an X-ray fluorescence spectrometer and presents its performance in elemental mapping applications. The spectrometer is based on a new ring-shaped collimator with a pinhole in the center of it and a ring-shaped Am-241 isotope mounted in the collimator as a source for excitation of X-ray fluorescence. The photons were detected by high-resolution Si (Li) detector coupled to a multi-channel analyser and cooled by liquid nitrogen. In this study, we used two samples; one of them was made from pure elemental powders, and the second one was a piece of a stone and three types of maps were plotted. In the maps type one, the areas of the elements were shown with a single color. These maps only show the location of the elements in the sample. In the maps type two, the area of each element was shown with different colors because of the count (intensity) related to the area. In the third type of the maps for each element, depending on the elements' position on the sample, the counts were plotted in three dimensions. The areas with higher intensity have greater height, and areas with lower intensity have lower altitude. These two last types of maps provide information about the homogeneity or heterogeneity of the elemental distribution in the samples. The spectrometer can perform non-destructive analyses of samples and objects in the air. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 16.05.2017

A new quantitative X-ray system for micro-PIXE analysis

Particle Induced X-ray Emission is a well-established technique for quantitative elemental analysis down to trace levels. During microbeam analysis, where the beam is collimated and focused into a small spot, the beam current reduces to nA or less. The generation of characteristic X-rays is reduced in the same proportion, leading to long data-acquisition times. This can partly be compensated for by using detectors with a large solid angle. In this work, the performance of an annular eight-element silicon drift detector with a total solid angle of 261 msr is described. The initial calibration of the detector was performed using thin elemental standards. Charge measurement was carried out both in a Faraday Cup positioned after the sample and by a pre-sample electrostatic deflection system sampling the beam charge into another Faraday Cup. The two methods were used in parallel and compared during the calibration measurements. A recently installed Versa Module Europe (VME) based data acquisition system equipped with, for example, multi-hit time-to-digital converters, amplifiers, and 32-channel scalers, was used to record data in event-by-event mode for simultaneous data evaluation on multiple computers. Off-line dead time and pile-up corrections were made on the event data that was sorted into spectra and fitted with the GeoPIXE software. The pre-sample deflection charge measurement gave consistent values for the calibration, and this is an important observation implying that non-conductive and thick samples will be able to quantify without the use of internal standards. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 16.05.2017

Combined control of aluminum bath composition by X-ray diffraction and X-ray fluorescence analysis

The present paper provides a combined application of X-ray diffraction (XRD) and X-ray fluorescence (XRF) methods in process control for the analysis of aluminum baths of different compositions. Developed approaches to the combined calibration XRD and XRF methods, independent calibration XRF techniques and to the full-profile automated Rietveld analysis of a bath composition are described. We established that combined XRD–XRF calibration techniques provide an accurate stable analysis of technological parameters in a wide range of traditional and low-melting compositions due to an accurate quantification of CaF2, MgF2 and KF additives. The developed XRF techniques provide quantitative analysis of both cryolite ratio and alumina with the accuracy of 0.03 and 0.25% wt. respectively, which is comparable with the technologically required accuracy. The evolutionary approach that automates full profile quantitative XRD analysis of bath composition and uses XRF data on Ca and Mg provides a better accuracy of measuring cryolite ratio compared to an accuracy of non-automated analysis by Rietveld method. Combined application of the two X-ray methods eliminates gross analytical errors and stabilizes overall performance of a smelter's process control system. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 12.04.2017

Is N a sufficient measure of the standard uncertainty in X-ray spectroscopy?

There is a magnitude larger scatter in the experimental data of fundamental parameters than the claimed error estimate. We give examples from recent compilations of excitation and decay parameter values for the untenable large scatters, indicating methodological problems. One is the improper use of uncertainty estimation. The measured spectrum is not expected to follow Poisson distribution. We report proper statistical uncertainty calculations. It implies a two to five times larger uncertainty but still does not account for the large scatter. The other possible explanation could be rooted in the ill-posed problem of exponential analysis, as radiation measurement belongs to this category. We give evidence from particle-induced X-ray emission and X-ray fluorescence for additional exponential terms, thus leading to multi-exponential analysis. This could explain the large scatter, as the usual square root of counts rule cannot be used for the standard uncertainty. We present a novel approach where discriminators are used to reduce the number of exponentials and the discriminated events are also processed and collected into a separate spectrum. Analyzing both spectra and the live time and dead time clocks allows the determination of the true input counts. It is a non-extended dead time approach. With this approach, we have a much reduced statistical uncertainty, and both the total spectrum and the fractional spectrum have the same uncertainty. As an independent quality assurance tool, the time interval histogram analysis is also presented. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 05.04.2017

Large-scale high-resolution micro-XRF analysis of histological structures in the skin of the pigeon beak

Histological analysis of biological structures in the avian beak is performed by means of large-scalehigh-resolutionmicro-X-ray fluorescence analysis using a Maia detector system. Element maps of S, K, Ca, Fe and Zn of square millimeter sizes show distinct cellular and subcellular tissue structures in semi-thin sections with a resolution at the (sub-)micrometer scale. Non-destructive qualitative and quantitative evaluation of the respective trace elements can be performed on the tissue samples. The elemental maps are compared with conventional differential histological stainings of parallel sections. This method is discussed as a pre-examination tool for subsequent analysis of selected structural sites by diffractive and spectroscopic X-ray nanoprobe techniques and, after additional ultrasectioning, also by transmission electron microscopy. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 30.03.2017

Towards a multi-element silicon drift detector system for fluorescence spectroscopy in the soft X-ray regime

In spite of the constant technological improvements in the field of detector development, X-ray fluorescence (XRF) in the soft X-ray regime remains a challenge. The low intrinsic fluorescence yield for energies below 2 keV indeed renders the applicability of low-energy XRF still difficult. Here, we report on a new multi-element multi-tile detection system currently under development, designed to be integrated into a soft X-ray microscopy end station. The system will be installed at the TwinMic beamline of Elettra synchrotron (Trieste, Italy) in order to increase the detected count rate by up to an order of magnitude. The new architecture is very versatile and can be adapted to any XRF experimental setup. Even though the first results of the previous version of such a multi-element system were encouraging, several issues still needed to be addressed. The system described here represents a further step in the detector evolution. It is based on four trapezoidal-shaped monolithic silicon drift detector tiles (matrices) with six hexagonal elements each equipped with a custom ultra-low noise application-specific integrated circuit readout. The whole signal processing chain has been improved leading to an overall increase in performances, namely, in terms of energy resolution and acquisition rates. The design and development of this new detection system will be described, and recent results obtained at the TwinMic beamline at Elettra will be presented. Future perspectives and improvements will also be discussed. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 21.03.2017

Study of the uniformity of aerosol filters by scanning MA-XRF

Energy-dispersive X-ray fluorescence (XRF) is an attractive analytical method to determine the level of air pollution by heavy metals. The concentration of the filter in ng/cm2 is obtained by direct comparison of the net characteristic line intensity of an element with that of a thin film standard. As the sampled area on the filter and the area of the standard are larger than the area analysed by the instrument, the distribution of the elements on the surface of both samples and standards have to be sufficiently uniform. If this is not the case, biased concentration estimates are obtained. Two scanning macro-XRF setups with a beam diameter of ~0.5 mm were used to investigate the distribution of elements in (1) commercially available (Micromatter) standards, (2) in-house quartz filter standards obtained with an aerosol generator and (3) particulate matter (PM10) collected on quartz filters by a Leckel SEQ 47/50 sampler. The uniformity of the Micromatter standards was better than 2%. At least some in-house standards showed a concave distribution with less material at the edges. The maximum bias introduced by this is less than 5%. Because of the limited sensitivity of scanning XRF compared with conventional XRF, the distribution of only a few common elements like Ca and Fe could be determined reliably in aerosol filters. The distribution of some heavy elements could only be measured in filters sampled in polluted regions. In general, the loading of particulate matter over the filters was uniform. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 21.03.2017

Measurement of K fluorescence yields of niobium and rhodium using monochromatic radiation

Both reactions Nb-93(n,n′)Nb-93 m and Rh-103(n,n′)Rh-103 m are of particular importance for dosimetry in reactor, and the measurement of the activity of Nb and Rh dosimeters provides the basic data that can be traced back to the reactor operating information. These radionuclides emit only X-rays of which emission intensities in recommended data are determined thanks to the γ-ray transition probabilities and fluorescence yield values. In general, the knowledge of fluorescence yields is rather poor and based on old measurements. Nowadays, the use of tunable monochromatic X-ray sources allows performing optimized measurements. In a first step, accurate values of the attenuation coefficients are measured at the metrology beam line of the SOLEIL synchrotron, using procedures such as optimized for similar measurements. In a second step, the fluorescence yields are determined using experimental approaches in a traditional experimental configuration. For both materials, several incident energies are used to get experimental spectra with energy-dispersive spectrometer. The peaks of interest are processed using the COLEGRAM software, which allows detailed fitting of the peak shape. The K fluorescence yields are derived with about 2% relative uncertainty. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 15.03.2017

Relative total L-subshell X-ray emission intensities and their impact on the fitting of complex X-ray fluorescence spectra

Relative total L-subshellX-ray emission intensities, IL2/IL3 and IL1/IL3, are reported for the elements Er, Tm, Yb, Hf, Ta, W, Pt and Au, measured using approximately monoenergetic X-rays at 17.4 keV. X-ray spectra were recorded using a filtered X-ray tube source and a silicon drift detector. Careful fitting was used to determine the intensities of the individual line transitions, accounting for line broadening and detector artefacts. The line intensities were summed to obtain the L1, L2 and L3 total X-ray emission rates. Relative total L-subshell emission intensities were also calculated using recommended values of subshell photoionization cross sections, fluorescence yields and Coster–Kronig transition probabilities. We find poor agreement between these accepted literature values and our experimental results. A simple modelling exercise was conducted to explore the impact on fitting complex L-shellX-ray fluorescence spectra using inaccurate literature values for line intensities and total subshell X-ray emission rates. We find that large errors can be introduced when fitting with incorrect values for the total relative X-ray emission from different L-subshells. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 07.03.2017

EDXRF analysis of gold jewelry from the Archaeological Museum of Taranto, Italy

Forty-six ancient gold jewelry, known as ‘Ori di Taranto’ and dated in Hellenistic period (VII–VI century bc), were found in Taranto (Southern Italy) and, nowadays, are exhibited in the National Archaeological Museum. These artifacts have never been analyzed, few information are reported in the bibliography, and nothing is known about their chemical composition. The aim of our work is to determine the chemical composition of the alloy and of eventual decorations present on the objects by using non-destructive, non-invasive, and in situ analysis. In particular, the samples were studied by energy dispersive X-ray fluorescence. Most of the analyzed samples show approximately same composition of the alloy (gold, silver, and copper, respectively equal to 96.3 ± 2.0% wt, 2.8 ± 1.9% wt, and 0.9 ± 0.3% wt) except nine samples. Multivariate statistical analysis was carried out in order to identify possible correlations and/or differences of alloy composition among the analyzed samples. Experimental results obtained could be compared with other jewelry of the same historical period, and therefore, this study can help to understand the type of processing of gold jewelry in the Hellenistic period. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 06.03.2017

Induced charge fluctuations in hemispherical semiconductor detectors

Among the compound semiconductors, a cadmium zinc telluride material (CdZnTe) is appealing for hard X-rayroom-temperature detectors for medical and astrophysical applications. Despite the attractive properties of CdZnTe material such as high atomic number, high density, wide-band gap, low chemical reactivity, and long-term stability, poor hole and electron mobility-lifetime products degrade the energy resolution of these detectors. For designing single polarity CdZnTe detectors insensitive to the hole transport, a hemispherical geometry is used. In this work, theoretical consideration of the stochastic process of charge induction in hemispherical geometry with accounting for electron trapping was considered. The formulae for the moments of the distribution function of the induced charge on the detector electrodes were derived. Copyright © 2017 John Wiley & Sons, Ltd. StartCopTextCopyright © 2017 John Wiley & Sons, Ltd.
Datum: 01.03.2017

Curve-fitting regression: improving light element quantification with XRF

Light elements are hard to quantify by X-ray fluorescence (XRF) spectrometry because, after a photoelectric excitation, they predominantly relax emitting Auger electrons, greatly reducing the fluorescence count thus limiting the signal-to-noise ratios (SNR) observed. Low SNR values have deleterious outcomes in model building. Notable in ordinary least squares (OLS) regression based on peak height, they also affect more robust regression methods, such as partial least squares regression. While low SNR can also be observed with low concentrations of heavier elements, this paper focuses on boron. To overcome the low SNR hurdle, curve-fitting regression (CFR), a novel method elaborated in this paper, seeks to fit full scans with summed Gaussian curves. The methodology was illustrated with pressed microcrystalline cellulose spiked with sodium tetraborate decahydrate (borax) powder samples. The calibration set ranged from 0% to 21.5% m/m boron, and a PANalytical Axios wavelength dispersive X-ray fluorescence system with rhodium source was used to perform the tests. A calibration curve with determination coefficient (R2) = 0.990 and root mean square error of calibration (RMSEC) = 0.7% m/m was produced with CFR versus RMSEC = 1.2% m/m with OLS regression. Validity of the method was tested with a set of 17 pearled samples containing a mixture of different oxides. Root mean square error of prediction (RMSEP) of 0.1% m/m was obtained with the validation set, using CFR against RMSEP = 0.99% m/m with OLS regression, thus illustrating the proposed method's potential. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 24.02.2017

Visualization method for radiographic films through silver intensity mapping using X-ray fluorescence

Radiographic films have a large range of applications. In many of these applications, the behavior of characteristic curves is very important for assessing the image quality and radiography setup. Radiographic film digitization and visualization are always performed by light transmission, and the characteristic curve is known as a behavior of optical density as a function of the radiation exposure. Because optical density is a function of metallic silver generated by chemical development in silver halides, when an image is visualized by light transmission, a silver amount map is indirectly seen. However, this measurement is limited by the optical instrument, and a very weak light signal cannot be distinguished from background light or background noise. In this way, highly exposed films can contain areas with different silver concentrations, but this cannot be seen because the optical density measurement is limited. One of the ways through which it is possible to overcome such limitation is to use a different method for ascertaining the quantity of silver remaining on the developed films, and one of the quantitative techniques that suit this purpose is X-ray fluorescence (XRF). The purpose of this paper is applying μ-XRF so as to obtain a point-by-point silver intensity map to detect objects with low optical contrast on conventional radiographic films. The results of this work have shown a higher linear range in measurement using XRF, and as consequence, small objects and details in low-contrast or overexposed radiographic images could be visualized by the silver mapping technique, and the same results could not be achieved using light transmission methods. A first approach about spatial resolution and contrast was made showing strong and weak points of this way to scan radiographic films. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 21.02.2017

Multielement concentration analysis of Swiss mice brains on experimental model of Alzheimer's disease induced by β-amyloid oligomers

Alzheimer's disease (AD) is an insidious, progressive, and irreversible brain disorder that leads to memory loss and severe cognitive decline. However, the discovery that soluble β-amyloid oligomers are potent central nervous system neurotoxins has led to a new view of AD pathogenesis. Metals, such as zinc, iron, and copper, are all increased in the aged brain, and the contents of those metals in the brain of AD patients are higher than non-AD people. So, altered homeostasis of metal may result in the development of AD. Total reflection X-ray fluorescence analysis (TXRF) is a multielement analytical technique, which can be used for elemental trace analysis. In this work, TXRF was used to evaluate the elemental concentration and distribution on mice brain regions. Three groups were studied: control, AD10, and AD100, being the two latter were given a single intracerebroventricular injection of 10 pmol and 100 pmol (β-amyloid oligomers), respectively, to induce experimental AD. All samples were submitted to acid digestion. The TXRF measurements were performed at the X-Ray Fluorescence Beamline at Brazilian National Synchrotron Light Laboratory, using a monochromatic beam (11.5 keV) for the excitation. It was possible to determine the concentrations of the following elements: P, S, K, Fe, Cu, and Zn. Results showed differences in the elemental concentration in some brain regions between the AD groups and the control group. Furthermore, the difference in the hypothalamus in AD10 groups, both female and male, suggests an association between AD and changes in these elements. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 21.02.2017

Discovering the material palette of the artist: a p-XRF stratigraphic study of the Giotto panel ‘God the Father with Angels’

Elemental analysis, and in particular stratigraphic distribution of elements themselves, is a fundamental method to address the composition of materials, but its nature, often invasive, crashes with the necessity of avoiding artefacts' damage when dealing with Cultural Heritage objects. In fact, when work of art are involved, sampling is often forbidden, and transferring an artistic artefact to equipped laboratories is a not negligible issue. The skill to employ in situ non-destructive and non-invasive analytical method is essential. In this scenario, portable X-ray fluorescence (p-XRF) has become one of the most employed techniques due to the development of adaptable and open architecture instruments. In this paper, we show a new data analysis protocol and its application to XRF data acquired from a work by Giotto never studied before: ‘God the Father with Angels’ (ca. 1330, San Diego Museum of Art). The measurements have been performed in situ during the closing time of the exhibition ‘Giotto, l'Italia’ (Milano Palazzo Reale – 2 September 2015/10 January 2016). Combining the effectiveness of scanning p-XRF with the responsive of image spectroscopic analysis, we move step by step toward the discovery of Giotto's palette for the flesh tones in God the Father with Angels; our method allows to argue the stratigraphy of the painting without complementary measurements and, at the same time, provides a sequential and smart representation of complex data. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 17.02.2017

Quantitative total reflection X-ray fluorescence analysis of directly collected aerosol samples

In this paper, the results of a feasibility study, investigating a new quantification method of directly collected aerosol samples, are shown. As sampling substrates, quartz reflectors suitable for total reflection X-ray fluorescence analysis were used, and the spot patterns produced by a three-stage Dekati impactor were considered. For calibration, the mentioned spot patterns were simulated on the surface of quartz reflectors using a self-developed nanoliter deposition unit and multielement standard solutions. A droplet containing 5 ng of Y was applied in the center of each reflector and served as internal standard. Calibration standards and aerosol samples were prepared and analyzed in the same way. Linear calibration curves and good recovery rates were obtained. Aerosol samples were collected at the Atominstitut on quartz reflectors greased with petroleum jelly (‘Vaseline’). The Vaseline layer is removed by cold-plasma ashing, and afterwards, the internal standard is added. The samples can be then analyzed directly by total reflection X-ray fluorescence without any further chemical pretreatment steps. As an application of the described method, two indoor and two outdoor samplings were carried out. In the investigated size range (>1 μm), mostly crustal elements were found and Ca values exceeded 100 ng/m3 in the size fractions below 10 μm. Detection limits of around 10 pg/m3 were achieved for medium Z elements (Fe to Sr) in the largest size fraction, whereas values for the two smaller stages typically lie between 30 and 100 pg/m3. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 08.02.2017

CRONO: a fast and reconfigurable macro X-ray fluorescence scanner for in-situ investigations of polychrome surfaces

CRONO is a new portable and easy reconfigurable macro X-ray fluorescence scanner based on the energy dispersive X-ray fluorescence technique, which has been specifically designed for in-situ, fast, and non-invasive elemental mapping of polychrome surfaces. The main components are fully integrated into the detection head which includes an X-ray tube, a large area silicon drift detector, a microscope camera, two pointing lasers, a Helium gas purging set, and fast acquisition electronics. This very compact detection head is mounted on motorized stages (with a linear speed up to 45 mm/s) that allow the scanning of areas up to 450 × 600 mm2. Three collimators (0.5, 1, and 2-mm diameter) are software selectable to obtain different spot sizes on the sample. The typical measurement time for the full scanned area ranges from 1 h with the 2-mm collimator to about 9 h with the 0.5-mm collimator using a dwell time of 30 ms. Technical details and achievable performances of the instrument are presented and discussed along with an example of application which illustrates the value of the developed instrument in the investigation of paintings. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 08.02.2017

CASTOR, a new instrument for combined XRR-GIXRF analysis at SOLEIL

A new instrument called CASTOR is operated at the SOLEIL synchrotron facility and is dedicated to the characterization of thin films with thicknesses in the nanometer range. The instrument can combine X-ray reflectivity measurements with fluorescence (XRF) acquisitions and especially total reflection X-ray fluorescence-related techniques such as grazing incidence XRF. The instrument was successfully installed and operated on the two branches of the metrology beamline making possible experiments over a wide range of photon energies (45 eV to 40 keV). A heating sample holder was developed to allow the sample temperature to be controlled up to 300° C. Some examples of the first studies are given to illustrate the capabilities of the setup. Copyright © 2017 John Wiley & Sons, Ltd.
Datum: 13.01.2017

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