Synchrotron Radiation X-ray Fluorescence Research Articles

Reconstructing the Frequency of Catastrophic Floods on the Western Coast of the Sea of Japan Based on Sedimentary Proxy

The history of coastal catastrophic floods was reconstructed for the first time using the geochemical proxy in shelf sediments. The reconstruction is based on the identification of sediment layers accumulated on the shelf during the intensive discharge of the river runoff suspended matter from the land which does not contain bromine. The set of isotopic (AMS 14C, 210Pb, 137Cs), tephrastratigraphic, and paleomagnetic methods was used for the detailed chronology of sediments. The scanning of chemical composition of sediments with the step of 0.5–0.8 mm is performed using the synchrotron radiation X-ray fluorescence in the VEPP-3 storage of the Institute of Nuclear Physics of Siberian Branch of Russian Academy of Sciences. The history of catastrophic floods for the past 1800 years is reconstructed based on the typical variations in bromine concentration in one of the cores from the Amur Bay (the Sea of Japan). New methodological approaches to the flood signal extraction are proposed. The revealed inverse correlation between the frequency of floods caused by typhoons over the coast of the Sea of Japan and southern China agrees with the existing assumption on the change in their trajectories in different periods of global climate change.

Synchrotron Radiation X-ray Fluorescence Analysis of Inks of Ballpoint Pens and Rollerball Pens for Criminal Investigation

Synchrotron Radiation X-ray Fluorescence Analysis of Inks of Ballpoint Pens and Rollerball Pens for Criminal Investigation

Forensic Comparison of Automotive Aluminum Wheel Fragments Using Synchrotron Radiation X-ray Fluorescence with 18- and 116-keV Excitation X-rays.

The performance of synchrotron radiation X-ray fluorescence (SR-XRF) spectrometry for nondestructive discrimination of small fragments of automotive aluminum wheels was studied. Fragments (< 500 × 500 μm2 ) of 45 kinds of wheels were first analyzed by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and then by SR-XRF. Despite the Mg/Al intensity ratio being a useful identification index, SEM-EDS was not efficient enough because of the absence of other meaningful indicators of comparison. Conversely, pairwise comparison was conducted and a 92.9% identification was achieved via SR-XRF using 18-keV X-rays. Trace heavy elements in the high-energy region were detected by SR-XRF using 116-keV X-rays, and an 82.9% identification was obtained. Combined use of 18- and 116-keV X-rays allowed 98.2% identification. Hence, SR-XRF is a powerful tool for nondestructive discrimination of automotive aluminum wheels with high precision using trace elements in a wide energy region.

Long-term Monitoring of Metal Elements in Total Suspended Particle Aerosols Simultaneously Collected at Three Islands in Okinawa, Japan

In the present study, total suspended particle (TSP) aerosols were simultaneously collected using identical high-volume air samplers at three islands in Okinawa; Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS, Okinawa Island), from 2008 to 2012 Kume Island (KM, ca. 160 km south-west of CHAAMS), and Minami-Daitou Island (MD, ca. 320 km south-east of CHAAMS) from 2008 to 2010. The sample collected were analyzed using energy-dispersive X-ray fluorescence spectrometry (ED-XRF) and synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) to investigation long-range transport of metal elements to Okinawa from the Asian continent. From analytical data on samples collected at CHAAMS for five years, it was found that most elements (Ca, Fe, Ti, Mn, V, Cu, Ni, Pb, As, and Zn) in TSP aerosols showed higher concentrations in the period from October to May, when the continental air mass passed over Okinawa, regardless of Asian dust events. The annual average concentrations of Ni, Cu, Zn, As, Se, and Pb in TSP aerosol samples collected at three islands gradually decreased as the TSP aerosols traveled from west to east in any year. Based on the enrichment factors (EFs) and concentration ratios, it is considered that most of anthropogenic elements such as As, Pb, and Zn in TSP aerosols are derived from coal combustion in the Asian continent. Moreover, it is confirmed from the direction of the air mass reaching the sampling sites that Cu, Zn, As, and Pb in TSP aerosols were transported to the three islands in Okinawa by air mass not only from northwest and north, but also from the west. These TSP aerosols transported from the Asian continent may influences not only the atmospheric environment but also the concentrations of trace metals in coastal seawater in Okinawa, which have to be kept extremely low to preserve the diverse and unique ecosystem in coral reefs.

Quantitation and distribution of metallic elements in sequestra of medication-related osteonecrosis of jaw (MRONJ) using inductively coupled plasma atomic emission spectroscopy and synchrotron radiation X-ray fluorescence analysis.

Medication-related osteonecrosis of the jaw (MRONJ) is a serious adverse effect of antiresorptive agents like bisphosphonates. Abnormal concentrations of various trace metallic elements contained in bone minerals have been associated with MRONJ. In this study, we focused on trace metallic elements contained in the MRONJ sequestrum; their content and distribution were compared to those in osteomyelitis and non-inflammatory bones using inductively coupled plasma atomic emission spectroscopy (ICP-AES) and synchrotron radiation X-ray fluorescence analysis (SR-XRF). On ICP-AES analyses, various trace elements (Co, Cr, Cu, Fe, K, Mg, Ni, Sb, Ti, V, Pb) were significantly more in MRONJ sequestra than non-inflammatory bones. The Cu content was significantly higher in MRONJ sequestra than osteomyelitis and non-inflammatory bones. The Cu content in MRONJ sequestra was high even after decalcification. Additionally, Cu was distributed along the trabecular structures in decalcified MRONJ specimens, as observed using SR-XRF analysis. Therefore, this study was indicative of the characteristic behavior of Cu in MRONJ.

Development and prospect of biological effects and safety of nanomaterials

Nanomaterials have lots of unique physical and chemical properties, such as quantum size effect, surface effect and macroscopic quantum tunnel effect. The biological effects of nanomaterials might be different from those of bulk materials larger than microns even if their chemical compositions are same. Therefore, the biological effects and safety evaluation results obtained from the bulk materials might not be suitable for the nanomaterials. Since 2003, governments worldwide have initiated the researches on biological effects and safety issues of nanomaterials with increasing financial support. China is one of the earliest countries in the world to carry out researches on biological effects and safety issues of nanomaterials. And some research fields have entered the forefront of the world. The CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety established jointly by National Center for Nanoscience and Technology (NCNST) and Institute of High Energy Physics of Chinese Academy of Sciences (IHEP of CAS) was the first professional laboratory focusing on the biological effects and safety of nanomaterials in China. Scientists in this laboratory have done many in-depth studies of the relationship between the physical-chemical properties and biological responses of nanomaterials. They found several factors which affected the biological effects of carbon nanotubes significantly, such as nanoparticle-Crona, metal impurities, surface, size, shape and so on. They have also established multiple models for hazard recognition and risk assessment. Nanomaterials/nanoparticles (NMs/NPs) are exposed to human beings mostly through four routes, i.e., oral intake, skin contact, inhalation, and intravenous injection. Upon entering the body, NMs/NPs are quickly distributed into specific organs and then metabolized primarily by the liver. The final excretion of NMs/NPs usually occurs in the liver and kidney in the form of urine and feces. In general, the most important issues regarding the absorption, distribution, metabolism and excretion (ADME) processes of NMs/NPs include: (1) Where do and how much NMs/NPs get in (via absorption)? (2) Where do and how much NMs/NPs go (via distribution)? (3) How much, when do, and what form of NMs/NPs remain intact (via metabolism)? (4) Where do, how much, and what form of NMs/NPs stay in the system (via excretion)? At various stages of the ADME processes, the challenges for in vivo analysis of NMs/NPs may become largely different. Important analytical methods to resolve the analytical challenges for each absorption, distribution, metabolism and excretion (ADME) process are summarized. The state-of-the art techniques with high sensitivity and high resolution suitable for safety evaluation have been developed to ensure the sustainable development of nanotechnology, such as inductively coupled plasma mass spectrometry (ICPMS), inductively coupled plasma optical emission spectrometry (ICP-OES), nuclear analysis such as neutron activation analysis (NAA), laser ablation inductively coupled plasma mass spectrometry (LAICPMS), secondary ion mass spectrometry (SIMS), synchrotron radiation X-ray fluorescence spectroscopy (SRXRF), X-ray absorption spectroscopy (XAS), X-ray fluorescence spectroscopy (XRF), scanning transmission X-ray microscopy (STXM), transmission X-ray microscopy (TXM) and so on. In this review, we summarize these research progresses in recent years.

Fingerprinting multiple gold mineralization events at the Dome mine in Timmins, Ontario, Canada: Trace element and gold content of pyrite

The Dome mine is host to over 16 Moz of orogenic gold deposited during a period of up to 25 Ma through multi-stage enrichment. The earliest economic stage of veining is an extensive set of ankerite veins which were historically considered barren except where overprinted by subsequent veining events. Gold in these veins is intimately associated with pyrite mineralization, and three stages of pyrite growth have been identified (Py1,2,3). The trace element content of each stage of pyrite growth determined by dynamic-secondary ion mass spectrometry and synchrotron radiation x-ray fluorescence reveals that there were three auriferous fluid events, each with a unique gold and trace element fingerprint which can be related to deposits wide mineralization events. Early ankerite vein forming fluids were auriferous, lower temperature (200–250 °C) and deposited Py1 enriched in gold, metals and metalloids (As, Cu, Ni, Zn). Py2 growth is related to deposit wide quartz-tourmaline and quartz-fuchsite veining based on trace element geochemistry, Au:Ag, and associated mineral assemblages. This deposited Ni enriched pyrite, tellurides, galena, and gold with anomalously high Au:Ag ratios. There is also evidence for remobilization of early gold and trace elements from Py1 pyrite during the Py2 forming event. The final stage of gold endowment in the ankerite veins is related to a deposit (and camp) wide quartz veining event. Py3 growth is trace element (As, Ni, Cu) and Au poor with respect to Py1 and Py2, however, this veining event contributed the bulk of the ankerite vein gold endowment. The remobilization of gold and trace elements from sieve textured Py1 in addition to overprinting Py2 and Py3 and their associated gold endowments helps explain the difficulty in applying bulk rock trace element vectors to gold at the Dome mine. The work also provides conclusive evidence for the auriferous nature of early ankerite veining at the Dome mine, and reveals that the system was fertile for a period of over 7 to 25 Ma, a key component for the formation of a world-class deposit.

Nanoelemental selenium alleviated the mercury load and promoted the formation of high-molecular-weight mercury- and selenium-containing proteins in serum samples from methylmercury-poisoned rats

Selenite (Se4+) has been found to counteract the neurotoxicity of methylmercury (MeHg) in MeHg-poisoned rats. However, Se4+ has narrow range between its toxic and beneficial effects. Nanoelemental selenium (SeNPs) was found to be less toxic than other forms of Se such as Se4+. In this study, the effects of SeNPs on the load of mercury (Hg) in rats were investigated. Hyphenated technique based on size-exclusion chromatography coupled with UV and inductively coupled plasma mass spectrometry (SEC-ICP-MS) detection and synchrotron radiation X-ray fluorescence spectroscopy (SR-XRF) were used to analyze the Hg-Se-containing proteins in the serum from MeHg-poisoned rats. The Hg-Se-containing fractions monitored by UV and ICP-MS were further characterized by MALDI-TOF-MS. Elevated serum Hg and Se levels were found in MeHg-poisoned rats after SeNPs treatment. Three main Hg-containing bands with molecular weights (MWs) of 25, 62 and 140 kDa were detected in the control samples. Treatment with SeNPs increased the Hg content in proteins at 62 and 170 kDa and decreased the Hg content at 25 kDa. The fraction with 25 kDa was assigned to metallothioneins (MTs), and fractions with 40 and 75 kDa were assigned to albumin. This study showed that the low-toxicity SeNPs could reduce the Hg load in the tissues and promote the formation of high molecular weight Hg- and Se-containing proteins in MeHg-poisoned rats.

Annual Sedimentary Record From Lake Donguz-Orun (Central Caucasus) Constrained by High Resolution SR-XRF Analysis and Its Potential for Climate Reconstructions

Bottom sediments of the proglacial Lake Donguz-Orun situated at ~2500 m a.s.l. in the Elbrus Region (Central Caucasus) reveal regular laminae, characteristic of proglacial varved lakes. This is the first laminated sediment sequence recorded in the region. However, visual counting of the layers was restricted due to partial indistinctness of the lamination. In order to confirm the annual sedimentary cyclicity and proceed with annually resolved data, in addition to the visual identification we used high resolution geochemical markers. The upper 160 mm of the sediment core were scanned at 200 µm intervals using synchrotron radiation X-ray fluorescence analysis (SR-XRF). Additional ultrahigh resolution scanning at 30 µm increments was employed for the upper 20 mm of the core. The Rb/Sr and Zr/Rb ratios are interpreted to record annual changes in grain-size. Based on this geochemical assessment, we identified 88 annual layers covering the interval between 1922 and 2010, while visually we have been able to identify between 70 and 100 layers. The correctness of the geochemical results is confirmed by mean accumulation rates assessed by 137Cs and 210Pb dating. Cross-correlation between the ring width of local pine chronology and the layer thickness, identified as a distance between the annual Rb/Sr peaks, allowed for the accurate dating of the uppermost preserved year of the sediment sequence (AD 2010). Annually averaged elemental data were then compared with regional meteorological observations, glacier mass balance and tree-ring chronologies. The comparison revealed notable conformities: content of bromine is positively correlated with annual temperatures (r=0.41, p<0.01), content of terrigenous elements (major elements with the origin in watershed rocks) is positively correlated (up to r=0.44, p<0.01) with annual precipitation. A high statistically significant negative relationship is observed between the concentrations of terrigenous elements and tree-ring width of local pine chronology (up to r=-0.56, p<0.01). Taken together, these data point to a common composite climatic signal in the two independent records (lake sediments and tree rings) and confirm that the laminae represent annual layers (i.e., varves). These findings open opportunities for high resolution multiproxy climate reconstructions 300-350 years long using the longer sediment core and tree-ring records.

Implications of X-ray beam profiles on qualitative and quantitative synchrotron micro-focus X-ray fluorescence microscopy.

Synchrotron radiation X-ray fluorescence microscopy is frequently used to investigate the spatial distribution of elements within a wide range of samples. Interrogation of heterogeneous samples that contain large concentration ranges has the potential to produce image artefacts due to the profile of the X-ray beam. The presence of these artefacts and the distribution of flux within the beam profile can significantly affect qualitative and quantitative analyses. Two distinct correction methods have been generated by referencing the beam profile itself or by employing an adaptive-thresholding procedure. Both methods significantly improve qualitative imaging by removing the artefacts without compromising the low-intensity features. The beam-profile correction method improves quantitative results but requires accurate two-dimensional characterization of the X-ray beam profile.

Preparation of standard materials of aerosol particles for X‐ray fluorescence analysis using a small chamber sampling unit

We investigated the simple and rapid preparation of standard materials of major and trace elements in aerosol particles for X‐ray fluorescence (XRF) analysis to study long‐range transport of air pollutants in East Asia. Standard materials for calibration curve were prepared using a small‐chamber sampling technique consisted of a 3‐L cylindrical acrylic chamber, aerosol filter holder, flow meter, and vacuum pump. Prepared aerosol standard materials had an excellent homogeneity in 0.5 mm × 0.5 mm analytical area. XRF analysis was performed by a bench top energy‐dispersive X‐ray fluorescent spectrometer. For only arsenic analysis, synchrotron radiation XRF was applied because As‐Kα line (10.53 keV) was overlapped by Pb‐Lα line (10.55 keV) in a typical XRF measurement. The calibration curves of 15 elements (K, Ca, Ti, V, Mn, Fe, Ni, Cu, Zn, As, Se, Rb, Sr, Ba, and Pb) showed a good linearity. The prepared standard materials were applied to determine metal elements in total suspended particle (TSP) aerosols, which were collected at Kume Island in Okinawa, Japan, from June 2008 to June 2010, and analytical results in XRF were compared with those of inductively coupled plasma atomic mass spectrometry (ICP‐MS) or atomic absorption spectrometry (AAS). Analytical results of TSP aerosol between XRF and ICP‐MS or AAS had a strong correlation higher than 0.800 for all elements.

Comparative measurement of metal contents in raw and cooked rice samples prepared in different rice cookers using SR-XRF and health risk assessment

Rice is full of nutrients that are essential to humans, however, exposure to the high metal contents in rice could also pose potential health risks to consumers. This work aimed to investigate this safety concern using the synchrotron radiation X-ray fluorescence spectrometry (SR-XRF), which is considered one of the most advanced and accurate elemental analysis techniques, to quantify metal contents, namely Fe, Zn, Cu, Ca, and Mn, in raw and cooked rice samples in order to assess the potential health risks associated with rice consumption. The results indicated that cooked rice samples had lower Fe and Ca but higher Zn, Cu, and Mn contents than raw rice samples (p < 0.05). The highest changes in metal contents were the decrease in the Ca content, which was reduced up to 8.5 times in rice samples cooked with running water and was lower than the detection limit (< 2.0 mg kg−1) in rice samples cooked with de-ionized water. When comparing the average estimated weekly intake with the available provisional tolerable weekly intake (PTWI) issued by the World Health Organization (WHO), the results showed that Fe, Zn, and Cu had lower average estimated weekly intake values than the PTWI levels. In terms of chronic, non-carcinogenic health risk assessment, the individual hazard quotient (HQ) of each metal of interest was less than the limit (1.0). However, the hazard index (HI), which combined all HQ values, was 1.15, indicating possible chronic health risks from rice consumption. The results obtained from this work suggest that further investigation is needed to fully understand and to promote awareness of the health risks caused by rice consumption.

Copper complexation and solubility in high-temperature hydrothermal fluids: A combined study by Raman, X-ray fluorescence, and X-ray absorption spectroscopies and ab initio molecular dynamics simulations

Data for the solubility of CuS (reacting to Cu2S), Cu, and bornite + chalcopyrite + pyrite (reacting to Cu-Fe-S solid solution) in H2O + NaCl fluids were determined in situ using synchrotron-radiation X-ray fluorescence (SR-XRF) spectroscopy. The aqueous Cu concentrations ranged between 25 ppm at 500 °C, 320 MPa, 0.5 m NaCl and 760 ppm at 500 °C, 310 MPa, 4.78 m NaCl, increased with temperature along an isochore and with NaCl molality, and decreased with pressure. The X-ray absorption near edge structure (XANES) spectra of the fluid from dissolution of CuS or Cu in H2O + NaCl at 500 °C are nearly identical with published spectra of CuCl2−(aq), but differ significantly from reported spectra of Cu(I) in Cl-free hydrosulfide solutions.Raman spectra of H2O + HCl ± NaCl fluids reacted with CuS or, for comparison, metallic Cu were measured at temperatures to 600 °C and pressures to 2 GPa to test if this technique can provide additional information on the complexation of Cu(I) and on the solubility of copper in hydrothermal fluids. These spectra showed that CuCl2−(aq) was the most abundant Cu(I) species at all conditions. In addition, CuCl32−(aq) was observed at high HCl concentrations, but the Raman spectra provided no convincing evidence for Cu(I) complexation with H2S or S3− (HS−(aq) was below detection in these acidic fluids). Generally, there was an increase in the sum of the integrated intensities of the bands assigned to Cu complexes with increasing HCl concentration, and a decrease if sulfide was present. At all fluid compositions, the intensity of the Raman bands from CuCl stretching vibrations decreased with increasing pressure at constant temperature for single-phase fluids, without formation of additional bands. Based on ab initio modeling, the complexes CuCl2−(aq), Cu(HS)2−(aq), and Cu(HS)Cl−(aq) are not distinguishable by Raman spectroscopy, but the stretching vibration of Cu(I) complexes with H2S should occur at significantly lower wavenumbers.Overall, the results indicate that Cu(I) is transported predominantly as CuCl2−(aq) in reducing sulfur-free or H2S ± S3−-bearing chloridic hydrothermal fluids. The decrease in the Cu solubility in H2O + HCl ± NaCl ± H2S fluids with increasing pressure without a detectable change in speciation is caused by decrease in the formation constant of CuCl2−(aq) with pressure. Changes in the copper speciation and depressurization can be ruled out as causes for hydrothermal copper ore formation at high fluid densities above the critical density. At this condition, copper ore may precipitate by dilution, cooling in the presence of H2S, increase in pH, and/or an increase in the H2S activity.

Assessment of Toxic Metals and Hazardous Substances in Tattoo Inks Using Sy-XRF, AAS, and Raman Spectroscopy.

Synchrotron radiation X-ray fluorescence spectroscopy, in conjunction with atomic absorption and Raman spectroscopy, was used to analyze a set of top brand tattoo inks to investigate the presence of toxic elements and hazardous substances. The Cr, Cu, and Pb contents were found to be above the maximum allowed levels established by the Council of Europe through the resolution ResAP(2008)1 on requirements and criteria for the safety of tattoos and permanent makeup. Raman analysis has revealed the presence of a set of prohibited substances mentioned in ResAP(2008)1, among which are the pigments Blue 15, Green 7, and Violet 23. Other pigments that were identified in white, black, red, and yellow inks are the Pigment White 6, Carbon Black, Pigment Red 8, and a diazo yellow, respectively. The present results show the importance of regulating tattoo ink composition.

Nickel and platinum in high-temperature H2O + HCl fluids: Implications for hydrothermal mobilization

The dissolution of NiS and NiAs (nickeline) in 0.1 and 1 molal HCl at 400 °C, 80 MPa, and of PtAs2 (sperrylite) and Pt metal in 1 and 6.86 molal HCl at 500 °C, 80 MPa was studied in-situ using synchrotron radiation X-ray fluorescence and absorption spectroscopy. The Pt concentration in the fluid averaged 8 · 10−5 molal (12.8 ppm) during dissolution of Pt metal in 6.86 molal HCl, and was below the minimum detection limit (mdl; 2.6 · 10−5 molal) in all other experiments. Dissolution of NiS was congruent or nearly congruent. Equilibrium was attained rapidly in about 250 min at an initial HCl concentration of 1 molal HCl, and in about 500 min at 0.1 molal HCl. Addition of HCl resulted in a large increase in the Ni solubility from 7.2 · 10−3 molal Ni (423 ppm) at 0.1 molal HCl to 8.72 · 10−2 molal Ni (4959 ppm) at 1 molal HCl. Dissolution of NiAs in 0.1 and 1 molal HCl was incongruent. A steady state was not reached even at a run duration of more than 16 h, and the maximum recorded Ni concentrations in the fluid were much lower than the Ni solubility in the corresponding experiments with NiS at the same HCl molality. Measured K-edge XANES spectra in comparison with literature data indicated that arsenic in the fluid was present as As(V) and that nickel complexed with Cl and H2O as tetrahedral [NiCl2(H2O)2]0 and [NiCl3(H2O)]− and octahedral [NiCl2(H2O)4]0 species. In addition, Raman spectra of H2O + NiCl2 and H2O + NiCl2 + HCl solutions and of H2O + HCl fluids reacted with NiS crystals were acquired at temperatures (T) up to 600 °C and pressures (P) up to 1.15 GPa. All spectra at T ≥ 300 °C and P < 600 MPa showed a previously not reported Raman peak at ∼280 cm−1 together with a weaker peak at ∼230 cm−1. These peaks can be assigned to Ni–Cl vibrations. The band at 280 cm−1 was not detected at the other P-T conditions. Based on calculated vibrational frequencies available in the literature, it may stem from the species [NiCl4]2– or [NiCl2(H2O)4]0, although particularly the first assignment is in conflict with the information from published XAS data.The results of this study demonstrate that nickel is readily mobilized by acidic chloridic hydrothermal fluids, but platinum remains practically immobile in such fluids at any HCl concentration that is conceivable to occur in nature. Therefore, the enrichment of Pt relative to Ni in footwall-type deposits in the Sudbury District and the growth of large sperrylite crystals are likely related to magmatic processes. Furthermore, the experiments point to the importance of redox reactions for the mobilization and precipitation of arsenides and suggest that arsenate species are more stable in hydrothermal fluids than previously thought.

Iron transformations during low temperature alteration of variably serpentinized rocks from the Samail ophiolite, Oman

Partially serpentinized peridotites in the Samail ophiolite in the Sultanate of Oman currently undergo low temperature alteration and hydration both at shallow levels, with water recently in contact with the atmosphere, and at depth, with anoxic, reducing fluids. However, it is unclear how changes in the distribution and oxidation state of Fe are driving the production of energy-rich gases such as hydrogen and methane detected in peridotite catchments. We track the Fe transformations in a suite of outcrop samples representing a subset of the spectrum of least to most altered end-members of the Oman peridotites. We use microscale mineralogical and geochemical analyses including QEMSCAN, Raman spectroscopy, synchrotron radiation X-ray fluorescence (XRF) mapping, and electron microprobe wavelength dispersive spectroscopy. The less-altered peridotites possess a diversity of Fe-bearing phases including relict primary minerals (e.g. olivine, pyroxene, chromite) and secondary phases (e.g. serpentine and brucite). Raman spectroscopy and electron microprobe data (Si/(Mg + Fe)) indicate that much of the serpentine is significantly intergrown with brucite on the sub-micron scale. These data also indicate that the Fe content of the brucite ranges from 10 to 20 wt% FeO. The mineral assemblage of the highly reacted rocks is less diverse, dominated by serpentine and carbonate while olivine and brucite are absent. Magnetite is relatively rare and mainly associated with chromite. Goethite and hematite, both Fe(III)-hydroxides, were also identified in the highly altered rocks. Whole rock chemical analyses reflect these mineralogical differences and show that Fe in the partially serpentinized samples is on average more reduced (∼0.40–0.55 Fe3+/FeTotal) than Fe in the highly reacted rocks (∼0.85–0.90 Fe3+/FeTotal). We propose that olivine, brucite, chromite and, perhaps, serpentine in the less-altered peridotites act as reactive phases during low temperature alteration of the Oman peridotite. The pervasive oxidation of Fe(II) in the less-altered peridotites to Fe(III) in the most-altered peridotites during water-rock reaction in the subsurface of the Samail ophiolite may produce H2 which will influence the development of microbial energy sources and habitats, and carbon cycling and sequestration within the (ultra)mafic ocean crust.

Elemental Investigation of the Leaf and Seed of Coriander Plant by Synchrotron Radiation X-ray Fluorescence Spectroscopy

This study describes the potential of synchrotron radiation X-ray fluorescence spectroscopy technique for the investigation of elements present in the parts of the medicinally important coriander plant: leaf and seed. For this, X-ray fluorescence spectra of the leaf and seed of coriander plants have been recorded by exciting synchrotron radiation of energy 13 keV. The analyses of the procured spectrum show the presence of elements: potassium, calcium, titanium, chromium, manganese, iron, nickel, copper, zinc, and arsenic. A calibration free approach, PyMca has been used for the quantitative estimation of the detected elements in the leaf and seed of the coriander plant.

Megapixel multi-elemental imaging by Laser-Induced Breakdown Spectroscopy, a technology with considerable potential for paleoclimate studies

Paleoclimate studies play a crucial role in understanding past and future climates and their environmental impacts. Current methodologies for performing highly sensitive elemental analysis at micrometre spatial resolutions are restricted to the use of complex and/or not easily applied techniques, such as synchrotron radiation X-ray fluorescence micro-analysis (μ-SRXRF), nano secondary ion mass spectrometry (nano-SIMS) or laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Moreover, the analysis of large samples (>few cm²) with any of these methods remains very challenging due to their relatively low acquisition speed (~1–10 Hz), and because they must be operated in vacuum or controlled atmosphere. In this work, we proposed an imaging methodology based on laser-induced breakdown spectroscopy, to perform fast multi-elemental scanning of large geological samples with high performance in terms of sensitivity (ppm-level), lateral resolution (up to 10 μm) and operating speed (100 Hz). This method was successfully applied to obtain the first megapixel images of large geological samples and yielded new information, not accessible using other techniques. These results open a new perspective into the use of laser spectroscopy in a variety of geochemical applications.

High-resolution geochemical record for the last 1100 yr from Lake Toson, northeastern Tibetan Plateau, and its climatic implications

Knowledge of the origin of past climatic variations on annual to decadal timescales is important for assessing the likelihood of the occurrence of similar variations in the future. Here we present a high-resolution (82-μm) element record, obtained using Synchrotron Radiation X-ray Fluorescence, from the sediments of Toson Lake in the northeastern Tibetan Plateau. The record, which spans the last ∼1100 yr, exhibits variability on an annual to decadal scale. The results of principal component analysis of the element dataset indicates that the first three principal components reflect variations in detrital inputs (via runoff and possibly eolian activity), drought conditions and temperature variations, respectively. Spectral analysis of samples scores on these components reveals strong El Niño-Southern Oscillation (ENSO)-like variability at periods of 3–8 years which indicates that the regional climatic variability was effected by ENSO events over the last ∼1100 yr. On the centennial time scale, the element data and TOC record suggest a warm and dry climate during the Medieval Warm Period (MWP) and a cold and wet Little Ice Age (LIA). The early 20th century was a warm interval, and drier than the LIA but wetter than the MWP.

Reflectance imaging spectroscopy and synchrotron radiation X-ray fluorescence mapping used in a technical study of The Blue Room by Pablo Picasso

The existence of a portrait hidden beneath The Blue Room (1901) by Pablo Picasso prompted a comprehensive technical study of this early Blue period painting. Microanalysis of paint samples was combined with reflectance imaging spectroscopy (RIS) and synchrotron radiation X-ray fluorescence (SR-XRF) mapping to characterize the materials and structure of the paint layers and to understand the artist’s palette and use of color in both paintings. Microanalysis of paint samples provided detailed information about pigment mixtures and paint stratigraphy while the complementary data sets provided by RIS and SR-XRF yielded important information about pigment distribution in both pictures and clarified details of the underlying painting. Overall, the comprehensive study increased understanding of both pictures and added to the growing body of knowledge about Picasso’s early experimentation and evolving technique.