Characterising the chemistry of micropores in a sodic soil with strong texture-contrast using synchrotron X-ray techniques and LA-ICP-MS

Soils with strong texture-contrast between A and B horizons dominate the agricultural zones of the west and south of Australia. The B horizon is often sodic and of much finer texture than the A (or E) horizon above, and can have a bulk density as high as 2 g cm–3. When dry, these B horizons may severely impede the root growth of annual cereal crops. The objective of this study was to characterise the mineralogy and chemistry of fine pores at the interface of an E and a sodic B horizon of an Alfisol (Sodosol). Micro-X-ray fluorescence spectroscopy (μ-XRF) was used to locate the distribution of calcium (Ca), manganese (Mn), iron (Fe), zinc (Zn), and copper (Cu), and μ-X-ray absorption near edge structure (μ-XANES) spectroscopy or μ-X-ray absorption fine structure (μ-XAFS) spectroscopy to investigate speciation of Fe, Mn, Zn, and Cu around a pore. Both natural aggregates and thin sections were employed but measurements from thin sections were more useful because of the smaller thickness of the sample. The distribution maps showed that Ca was present in the pores but the other elements were not. Copper, Mn, and Zn were concentrated around the micropore. Manganese was always well correlated with Fe. Manganese was found in reduced form, i.e. Mn(II), and associated with phosphates, whereas Fe was in oxidised form and mostly associated with oxides. Zinc was mostly associated with carbonates (CO3), sulfates (SO4), and silicates (SiO4). The results were then compared with measurements by laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS). Only some of the observations made by μ-XRF were confirmed by LA-ICP-MS, most probably because of the superior detection limits of synchrotron-based μ-XRF.

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An X-ray Absorption Near-Edge Structure (XANES) Study on the Oxidation State of Chromophores in Natural Kunzite Samples from Nuristan, Afghanistan

Minerals ◽

10.3390/min10050463 ◽

2020 ◽

Vol 10 (5) ◽

pp. 463

Author(s):

Habib Ur Rehman ◽

Gerhard Martens ◽

Ying Lai Tsai ◽

Chawalit Chankhantha ◽

Pinit Kidkhunthod ◽

...

Keyword(s):

Oxidation State ◽

Inductively Coupled Plasma ◽

Oxidation States ◽

Transition Elements ◽

Edge Structure ◽

X Ray ◽

Inductively Coupled ◽

Valence States ◽

Icp Ms ◽

X Ray Absorption

Kunzite, the pink variety of spodumene is famous and desirable among gemstone lovers. Due to its tenebrescent properties, kunzite always remains a hot research candidate among physicists and mineralogists. The present work is continuing the effort towards value addition to kunzite by enhancing its color using different treatments. Before color enhancement, it is essential to identify the chromophores and their oxidation states. In this paper, the authors investigated the main impurities in natural kunzite from the Nuristan area in Afghanistan and their valence states. Some impurities in the LiAlSi2O6 spodumene structure were identified and quantified by using sensitive techniques, including Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), UV−VIS and X-ray absorption near-edge structure (XANES). LA-ICP-MS indicated many trace elements as impurities in kunzite, among which Fe and Mn are the main elements responsible for coloration. The oxidation states of these two transition elements were determined by the XANES technique. The study reveals that Mn is present in both Mn2+ and Mn3+ oxidation states, while Fe is present only in Fe3+ oxidation state.

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Microstructure of TiC/Amorphous Hydrocarbon Nanocomposite Coatings

Microscopy and Microanalysis ◽

10.1017/s1431927600034693 ◽

2000 ◽

Vol 6 (S2) ◽

pp. 440-441

Author(s):

D. M. Cao ◽

J. C. Jiang ◽

B. Feng ◽

W. J. Meng

Keyword(s):

Inductively Coupled Plasma ◽

High Hardness ◽

Ceramic Surface ◽

Edge Structure ◽

X Ray ◽

Inductively Coupled ◽

Transmission Electron ◽

Wide Range ◽

Mechanical Components ◽

X Ray Absorption

Application of an appropriate ceramic surface coating to mechanical components such as bearings and gears can provide longer life and increased performance reliability. Metal-containing hydrocarbon (Me-C:H) coatings possess high hardness, together with low friction and low wear rate. They have also been suggested to adhere better to metallic substrates. This combination of attractive mechanical/tribological properties makes Me-C:H coatings potentially useful for surface modification of a wide range of mechanical components.Using the technique of inductively coupled plasma (ICP) assisted vapor deposition[1], we have synthesized Ti-containing hydrocarbon (Ti-C:H) coatings with a wide range of Ti compositions[2]. Coating mechanical properties such as modulus and hardness have been measured by the technique of nanoindentation and correlated to Ti and hydrogen compositions[2,3].We have performed detailed microstructural examination of Ti-C:H coatings by transmission electron microscopy (TEM), Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy, and X-ray Absorption Near Edge Structure (XANES) spectroscopy.

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Seleno-l-Methionine Is the Predominant Organic Form of Selenium in Cupriavidus metallidurans CH34 Exposed to Selenite or Selenate

Applied and Environmental Microbiology ◽

10.1128/aem.01084-06 ◽

2006 ◽

Vol 72 (9) ◽

pp. 6414-6416 ◽

Cited By ~ 2

Author(s):

Laure Avoscan ◽

Richard Collins ◽

Marie Carriere ◽

Barbara Gouget ◽

Jacques Covï¿½s

Keyword(s):

Inductively Coupled Plasma ◽

High Performance ◽

Organic Form ◽

Edge Structure ◽

Cupriavidus Metallidurans Ch34 ◽

X Ray ◽

Inductively Coupled ◽

Cupriavidus Metallidurans ◽

Plasma Mass Spectrometry ◽

X Ray Absorption

ABSTRACT The accumulated organic form of selenium previously detected by X-ray absorption near-edge structure (XANES) analyses in Cupriavidus metallidurans CH34 exposed to selenite or selenate was identified as seleno-l-methionine by coupling high-performance liquid chromatography to inductively coupled plasma-mass spectrometry.

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An extended-X-ray-absorption-fine-structure study of bovine erythrocyte superoxide dismutase in aqueous solution. Direct evidence for three-co-ordinate Cu(I) in reduced enzyme

Biochemical Journal ◽

10.1042/bj2190985 ◽

1984 ◽

Vol 219 (3) ◽

pp. 985-990 ◽

Cited By ~ 71

Author(s):

N J Blackburn ◽

S S Hasnain ◽

N Binsted ◽

G P Diakun ◽

C D Garner ◽

...

Keyword(s):

Aqueous Solution ◽

Superoxide Dismutase ◽

Structure Study ◽

Reduced Form ◽

Edge Structure ◽

X Ray ◽

Absorption Fine ◽

Copper Site ◽

Erythrocyte Superoxide Dismutase ◽

X Ray Absorption

Copper and zinc K-edge e.x.a.f.s. (extended X-ray-absorption fine structures) were measured for the metal sites of oxidized and reduced bovine superoxide dismutase in aqueous solution. Detailed analysis of the spectra indicates that the copper site of the enzyme changes on reduction and is most probably co-ordinated to three imidazole groups at a shorter distance Cu-N(alpha) = 0.194 nm (1.94 A) in the reduced form compared with a co-ordination of four imidazole groups at 0.199 nm (1.99 A) and an oxygen atom from solvent water at 0.224 nm (2.24 A) in the oxidized form. Examination of the edge, near-edge structure and e.x.a.f.s. of the zinc sites indicates that the stereochemical changes at copper that accompany reduction introduce minimal perturbation on the stereochemistry at zinc.

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The new X-ray absorption fine-structure beamline with sub-second time resolution at the Taiwan Photon Source

Journal of Synchrotron Radiation ◽

10.1107/s1600577521001740 ◽

2021 ◽

Vol 28 (3) ◽

pp. 930-938

Author(s):

Chih-Wen Pao ◽

Jeng-Lung Chen ◽

Jyh-Fu Lee ◽

Meng-Che Tsai ◽

Chi-Yi Huang ◽

...

Keyword(s):

Fine Structure ◽

Spectral Measurements ◽

Edge Structure ◽

X Ray ◽

Xafs Spectroscopy ◽

Absorption Fine ◽

The Stability ◽

X Ray Absorption ◽

Photon Source

The new TPS 44A beamline at the Taiwan Photon Source, located at the National Synchrotron Radiation Research Center, is presented. This beamline is equipped with a new quick-scanning monochromator (Q-Mono), which can provide both conventional step-by-step scans (s-scans) and on-the-fly scans (q-scans) for X-ray absorption fine-structure (XAFS) spectroscopy experiments, including X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) spectral measurements. Ti and Te K-edge XAFS spectra were used to demonstrate the capability of collecting spectra at the limits of the working energy range. The Ni and Cu K-edge XAFS spectra for a Cu-doped Pt/Ni nanocomposite were acquired to test the performance of the newly commissioned beamline. Pt L 3- and Ru K-edge quick-scanning XAFS (QXAFS) spectra for standard Pt and Ru foils, respectively, revealed the stability of the q-scan technique. The results also demonstrated the beamline's ability to collect XAFS spectra on a sub-second timescale. Furthermore, a Zn(s)|Zn2+ (aq)|Cu(s) system was tested to indicate that the states of the Zn electrode could be observed in real time for charging and discharging conditions using an in situ/operando setup combined with QXAFS measurements.

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INCORPORATION OF Mo6+ IN FERRIHYDRITE, GOETHITE, AND HEMATITE

Clays and Clay Minerals ◽

10.1007/s42860-021-00116-x ◽

2021 ◽

Author(s):

Marcel G. Görn ◽

Ralph M. Bolanz ◽

Stephen Parry ◽

Jörg Göttlicher ◽

Ralph Steininger ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Structural Disorder ◽

Unit Cell ◽

Emission Spectrometry ◽

Charge Balance ◽

Unit Cell Parameters ◽

Edge Structure ◽

X Ray ◽

Cell Parameters ◽

X Ray Absorption

AbstractAmong all iron oxides, hematite (α-Fe2O3), goethite (α-FeOOH), and ferrihydrite (FeOOH⋅nH2O) are the most common mineral species. While immobilization of Mo6+ by surface adsorption on ferric oxides has been studied extensively, the mechanisms of incorporation in their structure have been researched little. The objective of this study was to investigate the relation between Mo content and its structural incorporation in hematite, goethite, and six-line ferrihydrite by a combination of X-ray absorption spectroscopy (XAS), powder X-ray diffraction (pXRD), and inductively-coupled plasma optical emission spectrometry (ICP-OES). Synthesized in the presence of Mo, the hematite, goethite, and six-line ferrihydrite phases incorporated up to 8.52, 0.03, and 17.49 wt. % Mo, respectively. For hematite and goethite, pXRD analyses did not indicate the presence of separate Mo phases. Refined unit-cell parameters correlated with increasing Mo concentration in hematite and goethite. The unit-cell parameters indicated an increase in structural disorder within both phases and, therefore, supported the structural incorporation of Mo in hematite and goethite. Analysis of pXRD measurements of Mo-bearing six-line ferrihydrites revealed small amounts of coprecipitated akaganéite. X-ray absorption near edge structure (XANES) measurements at the Mo L3-edge indicated a strong distortion of the MoO6 octahedra in all three phases. Fitting of extended X-ray absorption fine structure (EXAFS) spectra of the Mo K-edge supported the presence of such distorted octahedra in a coordination environment similar to the Fe position in the investigated specimen. Incorporation of Mo6+ at the Fe3+-position for both hematite and goethite resulted in the formation of one Fe vacancy in close proximity to the newly incorporated Mo6+ and, therefore, charge balance within the hematite and goethite structures.

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Homogeneous Incorporation of Gallium into Layered Double Hydroxide Lattice for Potential Radiodiagnostics: Proof-of-Concept

Nanomaterials ◽

10.3390/nano11010044 ◽

2020 ◽

Vol 11 (1) ◽

pp. 44

Author(s):

Do-Gak Jeung ◽

Tae-Hyun Kim ◽

Jae-Min Oh

Keyword(s):

Electron Microscopy ◽

Layered Double Hydroxide ◽

Inductively Coupled Plasma ◽

Hydrothermal Reaction ◽

Edge Structure ◽

X Ray ◽

Inductively Coupled ◽

Diffraction Patterns ◽

Double Hydroxide ◽

X Ray Absorption

Trivalent gallium ion was successfully incorporated into chemically well-defined MgAl-layered double hydroxide (LDH) frameworks through postsynthetic hydrothermal treatment. Quantitative analysis with inductively coupled plasma-mass spectroscopy exhibited that Ga3+ was first incorporated into LDH through partial dissolution-precipitation at the edge of LDH particle and homogeneously distributed throughout the particle by substitution of Ga3+ for Al3+ in LDH frame works. The powder X-ray diffraction patterns showed that the Ga3+ incorporation did not affect the crystal structure without evolution of unexpected impurities. The morphology and surface property of LDH evaluated by scanning electron microscopy and light scattering showed the preservation of physicochemical properties throughout 24 h of hydrothermal reaction. The distribution of incorporated Ga3+ was visualized with energy dispersive spectroscopy-assisted transmission electron microscopy, suggesting the homogeneous location of Ga3+ in an LDH particle. The X-ray absorption near-edge structure and extended X-ray absorption fine structure suggested that the Ga moiety was immobilized in LDH from 0.5 h and readily crystallized upon reaction time.

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Uranium XAFS analysis of kidney from rats exposed to uranium

Journal of Synchrotron Radiation ◽

10.1107/s1600577517001850 ◽

2017 ◽

Vol 24 (2) ◽

pp. 456-462 ◽

Cited By ~ 12

Author(s):

Keisuke Kitahara ◽

Chiya Numako ◽

Yasuko Terada ◽

Kiyohumi Nitta ◽

Yoshiya Shimada ◽

...

Keyword(s):

Chemical Nature ◽

Uranyl Acetate ◽

Proximal Tubules ◽

Tubular Damage ◽

Edge Structure ◽

Thin Sections ◽

X Ray ◽

Chemical Status ◽

X Ray Absorption ◽

Peak Widths

The kidney is the critical target of uranium exposure because uranium accumulates in the proximal tubules and causes tubular damage, but the chemical nature of uranium in kidney, such as its chemical status in the toxic target site, is poorly understood. Micro-X-ray absorption fine-structure (µXAFS) analysis was used to examine renal thin sections of rats exposed to uranyl acetate. The ULIII-edge X-ray absorption near-edge structure spectra of bulk renal specimens obtained at various toxicological phases were similar to that of uranyl acetate: their edge position did not shift compared with that of uranyl acetate (17.175 keV) although the peak widths for some kidney specimens were slightly narrowed. µXAFS measurements of spots of concentrated uranium in the micro-regions of the proximal tubules showed that the edge jump slightly shifted to lower energy. The results suggest that most uranium accumulated in kidney was uranium (VI) but a portion might have been biotransformed in rats exposed to uranyl acetate.

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Determination of Chromium(VI) Reduction by Acinetobacter haemolyticus using X-ray Absorption Fine Structure Spectroscopy

Malaysian Journal of Fundamental and Applied Sciences ◽

10.11113/mjfas.v4n2.50 ◽

2014 ◽

Vol 4 (2) ◽

Author(s):

Quek Hsiao Pei ◽

Shafinaz Shahir ◽

Liu Tao ◽

Wan Azlina Ahmad

Keyword(s):

Fine Structure ◽

Enzymatic Reactions ◽

Edge Structure ◽

X Ray ◽

Xafs Spectroscopy ◽

Absorption Fine ◽

Chromium Vi ◽

X Ray Absorption ◽

Acinetobacter Haemolyticus ◽

Exafs Spectra

Several types of microorganisms have been reported to reduce Cr(VI) to the less toxic Cr(III) via enzymatic reactions. The main purpose of this study is to determine the reduction of Cr(VI) by a locally isolated bacterium, Acinetobacter haemolyticus (A. haemolyticus) using the x-ray absorption fine structure (XAFS) spectroscopy. XAFS analysis consisted of both the x-ray absorption near-edge structure (XANES) and extended x-ray absorption fine structure (EXAFS) spectra. XANES spectra of the rinsed Cr(VI)-laden A. haemolyticus biomass indicated that chromium was only present in the form of Cr (III). The nearest atoms coordinated to Cr(III) were oxygens in an octahedral geometry. The longer Cr-O bond lengths (~1.97 Å) obtained from the EXAFS spectra corroborated the presence of chromium as Cr(III) bonded to oxygen. These findings demonstrate the ability of A. haemolyticus to reduce Cr(VI) to Cr(III) that was bound to oxygen atoms of the ligands in A. haemolyticus.

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Characterization of Local Chemistry and Disorder in Synthetic and Natural α-Al2O3Materials by X-ray Absorption Near-Edge Structure Spectroscopy

Journal of Applied Crystallography ◽

10.1107/s0021889898007778 ◽

1998 ◽

Vol 31 (6) ◽

pp. 890-898 ◽

Cited By ~ 5

Author(s):

Annibale Mottana ◽

Takatoshi Murata ◽

Augusto Marcelli ◽

Giancarlo Della Ventura ◽

Giannantonio Cibin ◽

...

Keyword(s):

Short Range ◽

Light Element ◽

Detectable Effect ◽

Edge Structure ◽

X Ray ◽

Xafs Spectroscopy ◽

Substitutional Defects ◽

X Ray Absorption ◽

Made In

X-ray absorption fine spectra at the AlKedge were measured experimentally and calculated theoreticallyviathe multiple-scattering formalism for chemically pure and physically perfect synthetic α-Al2O3(α-alumina), natural ruby/sapphire (corundum) and a series of artificial corundums produced for technical purposes and used as geochemical standards. The AlK-edge spectra differ, despite the identical coordination (short-range arrangement) assumed by O around Al, and vary slightly in relation to the slightly different chemistries of the materials (substitutional defects) as well as on account of the location taken by foreign atoms in the structural lattices (positional defects). A quantitative treatment of the observed changes is made in terms of short-range distortion of the coordination polyhedron and of medium- to long-range modifications in the overall structure, both induced by substitutions. In some technical corundums, the impurities of admixed β-alumina, where Al is both in fourfold and sixfold coordination, produce another small but detectable effect on AlKedges. Therefore, XAFS spectroscopy proves its potential for both measuring a light element such as Al and detecting minor coordination changes and dilute substitutions (∼1–3 wt% as oxide) of the absorber by other atoms, at least under the favourable conditions occurring in this system.

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