Apatite is present as an accessory phase in many meteorites and is often formed as a secondary product of aqueous alteration. Its propensity to incorporate rare earth elements (REE) results in apatite usually being the main REE-bearing phase in hydrously altered meteorites. Asteroid Ryugu is thought to have experienced pervasive aqueous alteration and material collected from the surface of Ryugu is expected to provide insight into asteroidal aqueous alteration processes without influence by terrestrial weathering. Morphologies and mineral associations of apatite grains from five rock fragments collected from the asteroid Ryugu by the Hayabusa2 spacecraft were examined and their REE concentrations were measured by synchrotron X-ray fluorescence (SXRF) spectroscopy. The main minerals associated with apatite are dolomite, magnetite, and pyrrhotite. Grain boundary corrosion of the interfaces between apatite assemblages and the surrounding matrix suggest that paragenetic formation on the asteroid was followed by a later episode of hydrous alteration. Light REE (LREE) concentration levels recorded at 20-150 times those of bulk CI levels together with a steady increase from LREE toward enrichment of medium REE (MREE, up to Er) at 50-400 times bulk CI levels may suggest postgenetic removal of LREE from Ryugu apatite grains by late-stage circulation of a hydrothermal fluid.
Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.
Reliable identification of chondrules, calcium‐aluminum‐rich inclusions (CAIs), carbonate grains, and Ca‐phosphate grains at depth within untouched, unprepared chondritic samples by a nondestructive analytical method, such as synchrotron X‐ray fluorescence (SXRF) computed tomography (CT), is an essential first step before intrusive analytical and sample preparation methods are performed. The detection of a local Ca‐enrichment could indicate the presence of such a component, all of which contain Ca as major element and/or Ca‐bearing minerals, allowing it to be precisely located at depth within a sample. However, the depth limitation from which Ca‐K fluorescence can travel through a chondrite sample (e.g., ∼115 µm through material of 1.5 g cm−3) to XRF detectors leaves many Ca‐bearing components undetected at deeper depths. In comparison, Sr‐K lines travel much greater distances (∼1700 µm) through the same sample density and are, thus, detected from much greater depths. Here, we demonstrate a clear, positive, and preferential correlation between Ca and Sr and conclude that Sr‐detection can be used as proxy for the presence of Ca (and, thus, Ca‐bearing components) throughout mm‐sized samples of carbonaceous chondritic material. This has valuable implications, especially for sample return missions from carbonaceous C‐type asteroids, such as Ryugu or Bennu. Reliable localization, identification, and targeted analysis by SXRF of Ca‐bearing chondrules, CAIs, and carbonates at depth within untouched, unprepared samples in the initial stages of a multianalysis investigation insures the valuable information they hold of pre‐ and post‐accretion processes in the early solar system is neither corrupted nor destroyed in subsequent processing and analyses.
The trace element content and distribution including rare Earth elements (REEs) measured in mm-sized asteroidal samples returned by JAXA's Hayabusa2 mission are important chemical parameters to decipher asteroid Ryugu's chronology of formation linked to early Solar System processes. In order to identify and analyze ancient Solar Nebula components, such as calcium-aluminum-rich inclusions (CAIs), by their trace element and REE content, a synchrotron beam with an incident energy of 90 keV is used to optimize the XRF signal and increase the information depth in the sample. The application of a (sub-)microscopic X-ray beam with such a high excitation energy not only allows for the detection of a wide range of heavy elements, but also to study their 3 dimensional distribution in mm-sized samples by means of X-ray fluorescence computed tomography (XRF-CT). The experiment was performed in anticipation of the initial analysis of the Hayabusa2 return samples at beamline ID15a of the European Synchrotron Radiation Facility (ESRF), Grenoble, France. The samples were analyzed with a focused beam of 0.5 x 0.5 mu m2, achieving limit of detection values as low as 0.5 ppm with an acquisition time of 1 s. Here we present results of scanning XRF(-CT) analysis of a mm-sized sample of the Murchison meteorite, a Mighei type chondrite (CM2), wherein a 9.6 x 11.5 x 8.2 mu m(3) CAI phase was detected and analyzed. The CAI grain is shown to be detectable throughout the entire sample volume (~700 mu m) during an XRF-CT scan over a full 360 & nbsp; angular range, thus proving the applicability of the method to study the microscopic distribution of high-Z elements at trace level concentration within millimeter-sized asteroidal particles.
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. First-principles calculations of X-ray absorption spectra at the K-edge of 3d transition metals: an electronic structure analysis of the pre-edge Delphine Cabaret, Amélie Bordage, Amélie Juhin, M. Arfaoui, Emilie Gaudry
Microbeam X-ray fluorescence (XRF) spectroscopy is applied, next to an art-historical analysis, to determine the time and place of origin of Chinese blue-and-white porcelain. In the performed experiments, two groups of kraak porcelain samples (A and B) have been analyzed with XRF spectroscopy to obtain quantitative data, (trace) elemental distributions and fingerprints within different regions of interest. The outcome was processed with Principal Component Analysis (PCA), and with the obtained results it was possible to conclude that the two groups show similar elemental fingerprints and were manufactured in the same time period with a comparable use of raw materials. Additionally, X-ray absorption spectroscopy (XAS) measurements have been performed on the pigment layer, confirming the use of Cobalt Blue as an underglaze pigment.
Every infection is a battle for trace elements. Neutrophils migrate first to the infection site and accumulate quickly to high numbers. They fight pathogens by phagocytosis and intracellular toxication. Additionally, neutrophils form neutrophil extracellular traps (NETs) to inhibit extracellular microbes. Yet, neutrophil trace element characteristics are largely unexplored. We investigated unstimulated and phorbol myristate acetate-stimulated neutrophils using synchrotron radiation X-ray fluorescence (SR-XRF) on the sub-micron spatial resolution level. PMA activates pinocytosis, cytoskeletal rearrangements and the release of NETs, all mechanisms deployed by neutrophils to combat infection. By analyzing Zn, Fe, Cu, Mn, P, S, and Ca, not only the nucleus but also vesicular granules were identifiable in the elemental maps. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) revealed a neutrophil-specific composition of Zn, Fe, Cu, and Mn in comparison with J774 and HeLa cells, indicating a neutrophil-specific metallome complying with their designated functions. When investigating PMA-activated neutrophils, the SR-XRF analysis depicted typical subcellular morphological changes: the transformation of nucleus and granules and the emergence of void vacuoles. Mature NETs were evenly composed of Fe, P, S, and Ca with occasional hot spots containing Zn, Fe, and Ca. An ICP-MS-based quantification of NET supernatants revealed a NETosis-induced decrease of soluble Zn, whereas Fe, Cu, and Mn concentrations were only slightly affected. In summary, we present a combination of SR-XRF and ICP-MS as a powerful tool to analyze trace elements in human neutrophils. The approach will be applicable and valuable to numerous aspects of nutritional immunity.
In this research, the transparent glaze layers of Chinese porcelain samples were investigated. Depending on the production period, these samples can be divided into two groups: the samples of group A dating from the Kangxi period (1661–1722), and the samples of group B produced under emperor Qianlong (1735–1795). Due to the specific sample preparation method and the small spot size of the X-ray beam, investigation of the transparent glaze layers is enabled. Despite the many existing research papers about glaze investigations of ceramics and/or porcelain ware, this research reveals new insights into the glaze composition and structure of Chinese porcelain samples. In this paper it is demonstrated, using micro-X-ray Fluorescence (μ-XRF) spectrometry, multivariate data analysis and statistical analysis (Hotelling's T-Square test) that the transparent glaze layers of the samples of groups A and B are significantly different (95% confidence level). Calculation of the Seger formulas, enabled classification of the glazes. Combining all the information, the difference in composition of the Chinese porcelain glazes of the Kangxi period and the Qianlong period can be demonstrated.
Because of its major contributions to the world economy and cultural heritage, Chinese porcelain and its technology can be considered as very important. In this research, the applicability of Raman spectroscopy and X-Ray Fluorescence (XRF) spectroscopy to study the pigments of the ruan-cai colour palette of Chinese porcelain dating from the 18th century was evaluated. Next to the investigations based on stylistic analysis, the use of other analysis techniques is important to obtain complementary information. Raman spectroscopy and XRF spectroscopy are two non-invasive, analytical techniques proven to be useful for the determination of the nature and composition of pigments used to decorate ceramics. As a result, analytical analysis allows us to retrieve more information about the production of Chinese porcelain. Based on visual inspection of the decoration, the objects could be divided into two groups and to evaluate the use of the combined analytical approach, all groups and subgroups were sampled. Before Raman and XRF analyses, the samples were cut, embedded and polished, in order to be able to measure the transversal section of the samples. In this way, each layer of the porcelain samples could be analysed separately. The results show that the blue colour is cobalt-aluminium oxide, in red zones haematite (alpha-Fe2O3) is present and the green area contains a mixture of CuO in a lead-rich basis and a solid solution of malachite (Cu2CO3(OH)(2)). The opaque yellow and white colours were identified as lead tin yellow type II (PbSn(1-x)SixO(3), where x similar to 0.25) and a lead arsenate, respectively.
The NASA Stardust mission used silica aerogel slabs to slowly decelerate and capture impinging cosmic dust particles for return to Earth. During this process, impact tracks are generated along the trajectory of the particle into the aerogel. It is believed that the morphology and dimensions of these tracks, together with the state of captured grains at track termini, may be linked to the size, velocity, and density of the impacting cosmic dust grain. Here, we present the results of laboratory hypervelocity impact experiments, during which cosmic dust analog particles (diameters of between 0.2 and 0.4 mu m), composed of olivine, orthopyroxene, or an organic polymer, were accelerated onto Stardust flight-spare low-density (approximately 0.01 g cm(-3)) silica aerogel. The impact velocities (3-21 km s(-1)) were chosen to simulate the range of velocities expected during Stardust's interstellar dust (ISD) collection phases. Track lengths and widths, together with the success of particle capture, are analyzed as functions of impact velocity and particle composition, density, and size. Captured terminal particles from low-density organic projectiles become undetectable at lower velocities than those from similarly sized, denser mineral particles, which are still detectable (although substantially altered by the impact process) at 15 km s(-1). The survival of these terminal particles, together with the track dimensions obtained during low impact speed capture of small grains in the laboratory, indicates that two of the three best Stardust candidate extraterrestrial grains were actually captured at speeds much lower than predicted. Track length and diameters are, in general, more sensitive to impact velocities than previously expected, which makes tracks of particles with diameters of 0.4 mu m and below hard to identify at low capture speeds (<10 km s(-1)). Therefore, although captured intact, the majority of the interstellar dust grains returned to Earth by Stardust remain to be found.
X-ray diffraction, Raman and infrared spectroscopic evidence for the inclusion of water-rich ringwoodite in diamond from Juína, Brazil, indicates that, at least locally, the Earth’s transition zone is hydrous to about 1 weight per cent.
A novel three-dimensional (3D) elemental micro-imaging method was tested at beamline P06 of PETRA III, based on full-field micro-XRF detection technology. As opposed to using a single-element energy-dispersive detector and microbeam excitation in a confocal arrangement [1,2], for these 3D-XRF experiments a unique energy-dispersive CCD-detector (SLCam [3]) was installed and characterized at P06 in combination with excitation by a linearly focused X-ray beam. During the 3D micro-XRF experiments the Kirkpatrick-Baez (KB) X-ray mirror system was used with the vertically focusing mirror moved out of the beam path, allowing the generation of a linearly focused beam, oriented in the vertical plane. The horizontal beam size was determined by a knife-edge scan using a 50 µm gold wire while the vertical beam size was determined using a PCO 4000 high resolution CCD camera which was positioned along the primary beam, downstream of the sample position. The obtained sheet-beam measured 5 µm horizontally by 1.37 mm vertically (FWHM) , which was used to illuminate and excite a vertical cross-section of the sample volume of interest at an energy of 18.2 keV. The technique was tested on diamonds containing inclusion clouds and larger (few 100 µm) inclusions. By scanning through the diamond in the z-direction (towards the detector) (see Fig.1) and
The unique potential of nanoscale elemental imaging of major/minor and trace-level elemental distributions within thin biological tissue sections of the ecotoxicological model organism Daphnia magna is demonstrated by synchrotron radiation nano-X-ray fluorescence (nano-XRF). The applied highly specialized sample preparation method, coupled with the high spatial resolution (∼180 nm) and high X-ray photon flux (6 × 10(11) photons/s) available at the European Synchrotron Radiation Facility (ESRF) ID22NI beamline proved to be critical for the high-quality visualization of (trace-)metal distributions on the submicron level within the target structures of interest. These include the branchial sacs on the thoracic appendages (epipodites) of D. magna, which are osmoregulatory regions where ion exchange occurs. For the main element of interest (Zn), detection limits of 0.7 ppm (3 ag) was reached in fast-scanning mode using an acquisition time of 0.3 s/pixel. As demonstrated, synchrotron radiation nano-XRF revealed the elemental distributions of Ca, Fe, and Zn within this osmoregulatory region on the submicron scale, aiding the exploration of possible detoxification mechanisms of Zn within D. magna at the subtissue level.
Recent studies have suggested that exposure of the freshwater invertebrate Daphnia magna to dietary Zn may selectively affect reproduction without an associated increase of whole body bioaccumulation of Zn. The aim of the current research was therefore to investigate the hypothesis that dietary Zn toxicity is the result of selective accumulation in tissues that are directly involved in reproduction. Since under field conditions simultaneous exposure to both waterborne and dietary Zn is likely to occur, it was also tested if accumulation and toxicity under combined waterborne and dietary Zn exposure is the result of interactive effects. To this purpose, D. magna was exposed during a 16-day reproduction assay to Zn following a 5 × 2 factorial design, comprising five waterborne concentrations (12, 65, 137, 207, and 281 μg Zn/L) and two dietary Zn levels (49.6 and 495.9 μg Zn/g dry wt.). Tissue-specific Zn distribution was quantified by synchrotron radiation based confocal X-ray fluorescence (XRF). It was observed that the occurrence of reproductive inhibition due to increasing waterborne Zn exposure (from 65 μg/L to 281 μg/L) was accompanied by a relative increase of the Zn burdens which was similar in all tissues considered (i.e., the carapax, eggs, thoracic appendages with gills and the cluster comprising gut epithelium, storage cells and ovaries). In contrast, the impairment of reproduction during dietary Zn exposure was accompanied by a clearly discernible Zn accumulation in the eggs only (at 65 μg/L of waterborne Zn). During simultaneous exposure, bioaccumulation and toxicity were the result of interaction, which implies that the tissue-specific bioaccumulation and toxicity following dietary Zn exposure are dependent on the Zn concentration in the water. Our findings emphasize that (i) effects of dietary Zn exposure should preferably not be investigated in isolation from waterborne Zn exposure, and that (ii) XRF enabled us to provide possible links between tissue-specific bioaccumulation and reproductive effects of Zn.