Portable x‐ray fluorescence spectrometer with a pyroelectric x‐ray generator

A portable x‐ray fluorescence spectrometer was assembled with an x‐ray generator that was driven by a 9 V dry electric battery. Several possible optimum geometries of the x‐ray generator and detector were evaluated, and the results showed that the intensity of fluorescent x‐rays was strong enough when the angle between the x‐ray generator and detector was as small as 30°. The geometrically optimized x‐ray spectrometer was applied to the analysis of paints, plastics and aluminum foils. Pigments in paint and toxic elements in plastic could be easily detected with on‐site analysis. Fe in aluminum foil was quantitatively determined down to the sub‐% level. The detection limit of Fe was 180 ppm for 100 s of measurement. Copyright © 2005 John Wiley & Sons, Ltd.     

Analysis of mural paintings using in situ non‐invasive XRF,FTIR spectroscopy and optical microscopy

An analytical protocol consisting of X‐ray fluorescence spectroscopy, optical microscopy and Fourier transform infrared spectroscopy was used to study the origin and the nature of the materials (pigments, binders and coating preparation) of the Fundenii Doamnei church mural paint from Bucharest. The main interest of the present study consisted in the original votive paint from narthex, painted in 1757 in a secco technique. During analysis, an unexpected pigment in the votive paint could be detected by the combined analytical techniques: ultramarine blue. Along with this pigment, the presence of gypsum binder based on egg and flax seed oil could also be evidenced. These results demonstrated a secco execution technique of the votive paint and also the presence of a restoration treatment. Moreover, during the present study, the components of the preparation layer and the constitutive pigments from both 1699 and 1757 years mural paints have been analyzed. Hence, the following pigments could be identified: vermilion, azurite, cinnabar, lead white, ochre, natural umber and gold, by using the combination of the analytical techniques. The novelty of our results consists in detecting the composition of the materials used in this church painting (fresco and a secco) during these 254 years since its first restoration. The results of these investigations pointed to the suitability of the non‐destructive and semi‐destructive analytical techniques in the complex characterization of the paints realized in different techniques, at different periods. Copyright © 2013 John Wiley & Sons, Ltd.     

Fluoropolymer‐based clear and white paint coatings composition analysis by X‐Ray fluorescence

A new method for the quantification of organic and inorganic phase fractions was developed for fluoropolymer/acrylic‐blend paints – clear and white paint coatings – on aluminum panels by using wavelength dispersive X‐ray fluorescence spectrometry (WDXRF). The method was developed for clear coat samples (only containing fluoropolymer and acrylic phases) as well as white paint samples by also measuring silica and titanium dioxide levels. Both WDXRF and X‐ray photoelectron spectroscopy (XPS), a surface technique, were investigated. For clear coat samples, we found that WDXRF provided far superior quantitative results to XPS, likely related to the extreme surface sensitivity of XPS, in this case a drawback more than a strength. For white paint samples, the X‐ray fluorescence spectrometry method achieved a relative accuracy typically better than 5% for the organic phases and better than 2% for the inorganic phases, for measurements on 8‐mm diameter samples. Copyright © 2013 John Wiley & Sons, Ltd.     

Study of fossil bones by synchrotron radiation micro‐spectroscopic techniques and scanning electron microscopy

Earlymost Villafranchian fossil bones of an artiodactyl and a perissodactyl from the Milia excavation site in Grevena, Greece, were studied in order to evaluate diagenetic effects. Optical microscopy revealed the different bone types (fibro‐lamellar and Haversian, respectively) of the two fragments and their good preservation state. The spatial distribution of bone apatite and soil‐originating elements was studied using micro‐X‐ray fluorescence (µ‐XRF) mapping and scanning electron microscopy. The approximate value of the Ca/P ratio was 2.2, as determined from scanning electron microscopy measurements. Bacterial boring was detected close to the periosteal region and Fe bearing oxides were found to fill bone cavities, e.g. Haversian canals and osteocyte lacunae. In the perissodactyl bone considerable amounts of Mn were detected close to cracks (the Mn/Fe weight ratio takes values up to 3.5). Goethite and pyrite were detected in both samples by means of metallographic microscopy. The local Ca/P ratio determined with µ‐XRF varied significantly in metal‐poor spots indicating spatial inhomogeneities in the ionic substitutions. XRF line scans that span the bone cross sections revealed that Fe and Mn contaminate the bones from both the periosteum and medullar cavity and aggregate around local maxima. The formation of goethite, irrespective of the local Fe concentration, was verified by the Fe K‐edge X‐ray absorption fine structure (XAFS) spectra. Finally, Sr K‐edge extended XAFS (EXAFS) revealed that Sr substitutes for Ca in bone apatite without obvious preference to the Ca₁ or Ca₂ unit‐cell site occupation.     

Synchrotron X‐ray microfluorescence measurement of metal distributions in Phragmites australis root system in the Yangtze River intertidal zone

This study investigates the distributions of Br, Ca, Cl, Cr, Cu, K, Fe, Mn, Pb, Ti, V and Zn in Phragmites australis root system and the function of Fe nanoparticles in scavenging metals in the root epidermis using synchrotron X‐ray microfluorescence, synchrotron transmission X‐ray microscope measurement and synchrotron X‐ray absorption near‐edge structure techniques. The purpose of this study is to understand the mobility of metals in wetland plant root systems after their uptake from rhizosphere soils. Phragmites australis samples were collected in the Yangtze River intertidal zone in July 2013. The results indicate that Fe nanoparticles are present in the root epidermis and that other metals correlate significantly with Fe, suggesting that Fe nanoparticles play an important role in metal scavenging in the epidermis.     

Ion beam induced phase transformation in Fe–Mn bilayers: a Mössbauer study

Ion‐beam mixing of Fe–Mn bilayers induced by 100 keV krypton ions in the dose range (0.1-15)×10¹⁵ ions/cm²has been studied by means of conversion electron Mössbauer spectroscopy and X‐ray diffraction. The results indicate that a dose of about 1 ×10¹⁵ Kr⁺/cm² is sufficient to induce an appreciable mixing between the two atomic species. The α-Fe(Mn)solid solution presents a maximum at this dose, while at higher doses also the ? and γFe–Mn phases are formed in an appreciable amount. Heating of irradiated samples evidences the metastable character of ? phase and favours the growth of the terminal structures γ-Fe(Mn) and α-Mn(Fe) of the Fe–Mn equilibrium phase diagram.     

Dimensional characterization of selected elements in airborne PM10 samples using μ‐SRXRF

Micro synchrotron radiation X‐ray fluorescence (μ‐SRXRF) is a powerful spectroscopy technique that uses synchrotron radiation to induce X‐ray fluorescence in samples and provides exhaustive information on the micron and submicron scale. Among the major advantages of μ‐SRXRF spectroscopy are its nondestructive nature and that samples can usually be analyzed without pretreatment. At the ESRF (Grenoble, France) ID‐21 beamline, we examined PM₁₀ samples collected at two sites in the Province of Trieste, Italy, in order to determine possible correlations among some low‐ to mid‐Z elements (S, Cl, K, Ca, Ti, V, Cr, Mn, and Fe), as well as investigated the possibility of using synchrotron radiation imaging techniques as a way to examine the granulometry of PM₁₀ particles containing the various chemical elements. A consistent significant correlation between Ca and S has been found, which, coupled with the data obtained in a related study, indicates that a major part of the sulfate is present as CaSO₄. Granulometry measurement via imaging techniques has shown that some elements such as Fe, Ca, and S are more amenable to this type of analysis than others. Additionally, the spatial homogeneity of a PM_2.5 certified reference material (NIST SRM‐2783) has been investigated by analyzing four adjacent areas on the certified sample (total area 1 mm²). The certified reference material has shown a percentage relative standard deviation less than 7% for Al, Si, P, S, Cl, K, Ca, V, Cr, and Fe, and close to 17% for Ti and Mn. Copyright © 2011 John Wiley & Sons, Ltd.     

Accurate determination of the Ca:P ratio in rough hydroxyapatite samples by SEM‐EDS,PIXE and RBS—a comparative study

The Ca:P ratio in a certified standard of hydroxyapatite was determined by X‐ray spectrometry (XRS), with the X‐rays excited by both electrons and ions using energy dispersive spectroscopy on the scanning electron microscope (SEM‐EDS) and particle‐induced X‐ray emission (PIXE). The certified value of Ca:P was accurately verified by 3 MeV ⁴He⁺ Rutherford Backscattering Spectrometry (RBS). We show that the demonstrably rough surface of this sample does not cause perturbation of the Ca:P ratio within the uncertainties of each of the XRS measurements. Copyright © 2009 John Wiley & Sons, Ltd.     

Mössbauer spectroscopy and X-ray diffraction study of FexMn0:70−xAl0:30 (0:40 < x < 0:70) alloys prepared by mechanical alloying

In order to study the structural and magnetic behaviour of Fe_xMn_0.70?xAl_0.30 (0.40≤x≤0.70) alloys prepared by mechanical alloying, Mössbauer spectroscopy and X‐ray diffraction techniques have been employed. All the alloys were prepared in 24 h and, in addition, for x=0.45 milling times of 4, 8, 12, 16 and 24 h were considered. X‐ray diffraction showed that all samples exhibit bcc‐type reflections. A slight decrease in grain size and a slight increase in lattice parameter with increasing Mn content were observed. For x=0.45, an increase in grain size with milling time has been evidenced. For this composition and 4 h of milling, the more intensive peak (1?1?0) was fitted with three peaks corresponding to that of Mn, Fe and the alloy, respectively. For 12 h milling only bcc peaks of the alloy were obtained. As the Fe concentration was increased beyond x=0.50, a phase change from paramagnetic to ferromagnetic, as well as an increment in the mean hyperfine field with x, was detected. For x=0.45 and 4 h of milling we registered the presence of both a single line, corresponding to the alloy, and a hyperfine field distribution with peaks in 27.5 and 23 T, as well as peaks at lesser fields. These peaks are associated to Fe sites with two or more Al and/or Mn atoms as next neighbours. These results are in agreement with those obtained by X‐ray diffraction.     

High-resolution fluorescence mapping of impurities in historical zinc oxide pigments: hard X-ray nanoprobe applications to the paints of Pablo Picasso

Here for the first time we describe the use of high resolution nanoprobe X-ray fluorescence (XRF) mapping for the analysis of artists’ paints, hierarchically complex materials typically composed of binder, pigments, fillers, and other additives. The work undertaken at the nanoprobe sought to obtain highly spatially resolved, highly sensitive mapping of metal impurities (Pb, Cd, Fe, and other metals) in submicron particles of zinc oxide pigments used in early 20th century artists’ tube paints and enamel paints, with particular emphasis on Ripolin, a popular brand of French house paint used extensively by Pablo Picasso and some of his contemporaries. Analysis revealed that the Zn oxide particles only contain a little Fe, proving that the highest quality Zn oxide pigment, free of Pb and Cd, was used for Ripolin house paints as well as artists’ paints. Nanoprobe XRF mapping also demonstrated that artists’ tube paints generally have more abundant fillers and additional whites (based on Pb, Ti, Ca) than Ripolin paints, which contain mostly pure zinc oxide. The chemical characterization of paints at the nanoscale opens the path to a better understanding of their fabrication and chemical reactivity.     

Evaluation of the utility of handheld XRF in meteoritics

We tested a handheld X‐ray fluorescence instrument with adaptable matrix correction for its suitability in meteoritics. We report here the instrument setup, precision and accuracy and present examples of applications. With a measuring time of 300 s, it is possible to collect accurate data for K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Sr and Ba that are needed for the identification of doubtful meteorites and the nondestructive classification of chondrites and achondrites. The factory‐supplied calibration curve of the instrument was fine tuned for our purposes with the use of well‐analyzed meteorite powders, pressed pellets and meteorite hand specimens as standards. Relative errors of 10% to 20% are reached for the mentioned elements. The instrument was tested in the hot desert of Oman while searching for meteorites and also in the laboratory while doing research on meteorites. The main applications of the instrument are the identification and classification of meteorites, the quantification of terrestrial elemental contamination (Sr and Ba) and detection of Mn‐rich desert varnish. It is possible to discriminate the major meteorite groups using Fe/Mn and Ni values. Handheld X‐ray fluorescence is also useful in identifying meteorites belonging to the same fall event. Copyright © 2011 John Wiley & Sons, Ltd.     

Raman microscopy of prehistoric paintings in French megalithic monuments

Remains of pictorial decorations in a series of six representative megalithic monuments of Brittany (France) and two French stelae have been studied by micro‐Raman spectroscopy for the first time. Fungal colonies on the painted orthostats made it difficult to obtain in situ Raman spectra of the paint components. Nevertheless, paint micro‐specimens studied in the laboratory by micro‐Raman spectroscopy, X‐ray photoelectron spectroscopy and scanning electronic microscopy combined with energy dispersive X‐ray spectroscopy have made possible to characterise the materials present. The minerals α‐quartz, albite, microcline, muscovite, phlogopite, celadonite, beryl and anatase have been identified in the granitic rocks supporting the paintings, while dolomite and calcite are dominant in the calcareous rocky substrata. Haematite is the main component of the red pictographs, whereas amorphous carbon and manganese oxides/oxihydroxides have been used in the black ones. Calcite, gypsum and amorphous carbon have been detected as additional components of the paint in some cases. Contamination with modern tracing materials (polystyrene and ε‐copper‐phthalocyanine blue) has been detected in several cases. The presence of pigments as decorative elements in megalithic monuments of Western France and its possible relation with those of the Iberian Peninsula create interesting expectations for the knowledge of the European megalithic culture. Copyright © 2015 John Wiley & Sons, Ltd.     

Investigation of a fossilized calotte from Lagoa Santa,Brazil, by EDXRF

The origin of the component parts of a fossilized calotte (skull cap) from Lagoa Santa in Brazil was investigated by using energy‐dispersive x‐ray fluorescence analysis. The specimen was irradiated with a miniaturized and low‐power x‐ray generator (2.25 W, tungsten anode). The calotte and rock samples from the two known sites have a similar chemical composition, especially rich in S, K, Ca, Ti, Mn, Fe, Cu, Zn, Pb, Br, Rb and Sr. These elements are associated with the geological constitution of the limestone complex where the archaeological samples were found. The small differences in the relative amount of each element, especially the Ca/Sr ratio, in different parts of the calotte reinforce the hypothesis that the calotte had been mounted with pieces from different origins. Copyright © 2005 John Wiley & Sons, Ltd.     

Characterization of Indian Ayurvedic herbal medicines for their metal concentrations using WD‐XRF spectrometry

This article describes the details of metal concentrations evaluated using wavelength dispersive X‐ray fluorescence (WD‐XRF) spectrometry. A total of 22 elements, Na, Mg, Al, Si, P, S, K, Ti, Ca, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Hg, Pb, Ba, Au, and Sn from 16 Ayurvedic medicines were characterized. The method was validated by analyzing the six certified reference materials of soil standards [NIST SRM‐2710, CRM 027‐050 (US‐EPA certified), PS‐1, TILL‐1 and TILL‐4 (Canadian certified reference material, CCRMP) and JSO‐1 (Japanese certified reference material)]. The elemental concentrations in all the standards are found to be within ± 10% of the reported values. Crystalline phases in the individual drug samples were explained by powder X‐ray diffraction (XRD) technique. Qualitative phase identification was done using the ICDD database. Copyright © 2010 John Wiley & Sons, Ltd.     

Speciation of selected metals in aerosol samples by TXRF after sequential leaching

Total reflection x‐ray fluorescence (TXRF) spectrometry was applied after sequential leaching for the speciation of selected elements in particulate matter, in order to complete the knowledge of the mobility of the selected elements and to determine which components are harmful to works of art. Samples were collected on filters in two churches, one situated in a rural area and the other in an urban area. A five‐stage sequential leaching scheme for the speciation of K, Ca, Fe, Zn and Pb was applied, the fractions obtained being as follows: exchangeable elements; elements bound to carbonates; elements bound to Fe and Mn oxides; elements bound to organic matter; and the digested insoluble residue. It was found that, in the case of the church in the urban area, much of the K, Fe and Zn appeared as mobile elements, whereas for the church situated in the rural area, the amounts of Ca and Fe were most mobile. Copyright © 2006 John Wiley & Sons, Ltd.     

A critical analysis of the application of EDXRF spectrometry on complex stratigraphies

In this work, the potentialities and limits of the investigation by portable energy‐dispersive X‐ray fluorescence (XRF) of complex polychrome stratigraphies are discussed. Data are affected by the mutual influence effects of the chemical elements that characterize mineral pigments, by the sequence and the thickness of the paint layers in the stratigraphies and by the size of pigment grains. Sequences of pictorial layers, which produce the typical stratigraphy of cold‐painted terracotta and wooden sculptures, have been prepared and then analysed by means of two portable X‐ray spectrometers: Innov X Systems Alpha 4000 (Tantalum X‐ray tube, 40 kV and 7 µA) and Assing Lithos 3000 (Molybdenum X‐ray tube, 25 kV and 300 µA). For each layer of pigment, the XRF spectrum was acquired and the areas of K and L peaks of characterizing elements were calculated. Moreover, the thickness of the layers was determined using XRF data following an algorithm already shown and the values have been compared with those measured on polished cross sections observed by optical microscope in reflected light. Copyright © 2011 John Wiley & Sons, Ltd.     

X‐ray fluorescence analysis of trace metals in environmental water using preconcentration with an iminodiacetate extraction disk

A simple and convenient x‐ray fluorescence analysis procedure for trace amounts of Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg and Pb in water was developed using preconcentration with an iminodiacetate extraction disk (IED). The IED was coated on both faces with commercially available laminate film to prevent x‐ray damage to the IED by strong x‐irradiation (4 kW; 50 kV, 80 mA) of the wavelength‐dispersive x‐ray fluorescence spectrometer. Lamination of the IED prolongs its life from 7 to about 200 min at 4 kW irradiation while negligibly decreasing the x‐ray fluorescence. Lowering the power of primary x‐rays to less than 1.5 kW compensated for the Hg evaporation. Linear calibration curves were obtained over the range 500 µg–5 mg for Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg and Pb. Detection limits corresponding to three times the standard deviation of the blank intensity were 0.1–0.4 µg for Mn, Co and Ni, 0.5–0.8 µg for Fe, Cu, Zn and Pb and 7 µg for Cd. A spike test for 10 µg of eight analytes, excluding Mn, showed good recoveries (90–100%) for city water and rainwater. Analytical results for municipal tap water and rainwater agreed well with values obtained using atomic absorption spectrometry. Copyright © 2006 John Wiley & Sons, Ltd.     

Combined PIXE and X‐ray diffraction analysis of accretionary lapilli from the Cretaceous/Paleogene boundary El Guayal Section,Tabasco, Mexico

By employing the techniques, X‐ray powder diffraction (XRPD) and particle‐induced X‐ray emission (PIXE), it could be obtained in a simply way an overall vision of the structure and chemical composition of a spheroid (lapillus) collected in the K/Pg deposit located at the place called El Guayal in Tabasco, Mexico. The XRPD analysis indicates the presence of an amorphous and four crystalline phases (quartz, calcite, ankerite, and montmorillonite) in the spheroid. None sulfur crystalline phases were detected. PIXE results show the presence of different atoms in a weight percentage that follows the sequence: Si > Al > Ca > Fe > Sr > Cu > Ti > Mn > Y > Rb > Zn > Pb. None of platinum group elements were detected. PIXE analysis by of the lapillus shows the presence of the most abundant atoms in the Earth's crust, but in this case, the relative abundance Fe‐Ca is inverted, and the Sr/Rb proportion is considerably higher than that observed in the crust. Additionally, nor sulfur or any of the platinum group elements was detected in the lapillus. Except for the case of trace elements detected, in general, no characteristic pattern is observed in the distribution of the most abundant elements. Copyright © 2015 John Wiley & Sons, Ltd.     

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.     

Time‐resolved x‐ray fluorescence for monitoring the intake of mineral nutrients in living plants

We have applied a time‐resolved means of measurement for studying living plants. The intake of mineral nutrients in a living plant such as stevia has been observed by this measuring instrument. A solution containing K, Ca, Mn, Fe, Cu, and Zn compounds was used as the mineral nutrient solution. The concentrations of the standard solutions were specifically chosen to obtain optimal intensities of the x‐ray peaks. The time dependence of the x‐ray fluorescence (XRF) intensity showed specific intake processes depending on the type of element. In addition, the experimental results suggest differences in the translocation of each element in the stevia stem. We conclude that time‐resolved XRF is a powerful technique for studying living plants. Copyright © 2007 John Wiley & Sons, Ltd.