XANES of chromium in sludges used as soil ameliorants

2003 ◽  
Vol 81 (2) ◽  
pp. 193-196 ◽  
Author(s):  
R R Martin ◽  
S J Naftel ◽  
T K Sham ◽  
B Hart ◽  
M A Powell
Keyword(s):  
Oxidation State ◽  
Chromium Content ◽  
Xanes Spectroscopy ◽  
Sewage Sludges ◽  
Edge Structure ◽  
Aqua Regia ◽  
X Ray ◽  
X Ray Absorption

Samples of sewage sludges proposed for use as soil ameliorants in an Indo-Canadian project were tested for chromium content. Standard aqua regia extractions found one sludge to have excessive amounts of Cr. X-ray absorption near-edge structure (XANES) spectroscopy, however, indicated that the Cr was present in the relatively benign Cr(III) oxidation state in all the sludge samples.Key words: soil, chromium, synchrotron, XANES.

Using X-ray absorption near edge structure (XANES) spectroscopy to determine selenium oxidation states in animal mineral supplements and feeds

2004 ◽  
Vol 84 (2) ◽  
pp. 171-175 ◽  
Author(s):  
C. R. Christensen ◽  
J. N. Cutler ◽  
D. A. Christensen
Keyword(s):  
Oxidation State ◽  
Animal Feed ◽  
Xanes Spectroscopy ◽  
Elemental Selenium ◽  
Selenium Speciation ◽  
Edge Structure ◽  
X Ray ◽  
Mineral Supplements ◽  
Animal Feeds ◽  
X Ray Absorption

Synchrotron-based X-ray absorption near edge structure (XANES) spectroscopy is a relatively new technique within the life sciences. XANES has been utilized to identify the location, oxidation state and spatial distribution of heavy metal elements in plants , neurons, blood and DNA, but has not been widely used in the animal sciences. Selenium content in animal feeds is monitored, as both selenium deficiencies and toxicities are associated with physiological disorders. Selenium is available as an animal feed in both inorganic and organic states. The bioavailability of selenium species has been tested in numerous animal trials; however, a simple, non-destructive test for selenium speciation is not available. The objective of this study was to determine whether XANES spectroscopy could be used to determine the selenium oxidation state found in various commercial animal feed products. A comparison of absorption spectra indicated that the animal mineral supplements contained an organoselenium or selenite. The processed animal feeds had a spectral profile similar to that of elemental selenium. Further experiments are necessary to determine the implication of selenium speciation on animal physiology. Key words: Selenium speciation, mineral supplements, ruminants, non-ruminants, synchrotron, XANES, X-ray

Using XANES to Monitor the Oxidation State of Cobalt Complexes

2007 ◽  
Vol 60 (3) ◽  
pp. 180 ◽  
Author(s):  
Matthew D. Hall ◽  
Clare K. Underwood ◽  
Timothy W. Failes ◽  
Garry J. Foran ◽  
Trevor W. Hambley
Keyword(s):  
Oxidation State ◽  
Cobalt Complexes ◽  
Reducing Agents ◽  
Oxidation States ◽  
Xanes Spectroscopy ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

X-Ray absorption near-edge structure (XANES) spectroscopy was used to monitor the oxidation state of cobalt following treatment of CoIII complexes with reducing agents such as ascorbate and cysteine. It was established that the XANES spectra of mixtures of CoII and CoIII complexes can be used to calculate proportions of the two oxidation states by monitoring the height of the Co K-edge. The relationships developed were used to estimate proportions of each complex in solutions of CoIII complexes treated with reducing agents.

Discrepancy in the quantitative oxidation-state analysis of Eu species in sulfide phosphors by K-, L1- and L3-edge XANES spectrometry: choice of absorption edge and measurement mode

2018 ◽  
Vol 33 (4) ◽  
pp. 585-592 ◽  
Author(s):  
Takashi Yamamoto ◽  
Akira Yukumoto
Keyword(s):  
Quantitative Analysis ◽  
Oxidation State ◽  
Absorption Edge ◽  
Oxidation States ◽  
Xanes Spectroscopy ◽  
Edge Structure ◽  
X Ray ◽  
Measurement Mode ◽  
Constituent Elements ◽  
X Ray Absorption

A quantitative analysis of the oxidation state of europium (Eu) in phosphor samples was performed using X-ray absorption near-edge structure (XANES) spectroscopy to investigate the influence of the constituent elements, absorption edge and measurement mode on the evaluated oxidation states.

scholarly journals Performance of secondary P-fertilizers in pot experiments analyzed by phosphorus X-ray absorption near-edge structure (XANES) spectroscopy

AMBIO ◽  
2017 ◽  
Vol 47 (S1) ◽  
pp. 62-72 ◽  
Author(s):  
Christian Vogel ◽  
Camille Rivard ◽  
Verena Wilken ◽  
Andreas Muskolus ◽  
Christian Adam
Keyword(s):  
Xanes Spectroscopy ◽  
Edge Structure ◽  
X Ray ◽  
Pot Experiments ◽  
X Ray Absorption ◽  
P Fertilizers

Oxygen Reduction Effect on T’-Pr2-xCexCuO4 Nanopowders in the Underdoped Regime Studied by X-Ray Absorption near Edge Structure

2018 ◽  
Vol 936 ◽  
pp. 93-97 ◽  
Author(s):  
Irfanita Resky ◽  
Putu Eka Dharma Putra ◽  
Triono Bambang ◽  
Saiyasombat Chatree ◽  
Kamonsuangkasem Krongthong ◽  
...  
Keyword(s):  
Oxidation State ◽  
Oxidation States ◽  
Edge Structure ◽  
X Ray ◽  
Reduction Annealing ◽  
Gas Atmosphere ◽  
Reduction Effect ◽  
Ar Gas ◽  
X Ray Absorption ◽  
Cu Ions

This research is aimed to examine oxidation state of Copper (Cu) in both as-synthesized and reduced T’-Pr2-xCexCuO4 (T’-PCCO) with x = 0, 0.10, and 0.15 using Cu K-edge x-ray absorption near edge structure (XANES). The T‘-PCCO nanopowders were successfully synthesized by the chemically dissolved method with HNO3 as a dissolving agent continued by calcination at 1000°C for 15 h. The reduced T’-PCCO nanopowders were obtained by reduction annealing process at 700°C for 5 h under Ar gas atmosphere. The analyses of XANES spectra show that oxidation states of the Cu ions in all of the T'-PCCO nanopowders have values between +1 and +2. This indicates the existence of electron doping in the CuO2 planes, even in the undoped T’-structure. It is found that the oxidation states of the Cu ions change after reduction annealing depending on the existence of apical oxygen in the T'-structure. Based on the XANES analyses, it is revealed that the change of oxidation state is influenced by the presence of both electron and hole carriers in the two-carrier model of T’-structure.

Phosphorus K-edge XANES spectroscopy has probably often underestimated iron oxyhydroxide-bound P in soils

2018 ◽  
Vol 25 (6) ◽  
pp. 1736-1744 ◽  
Author(s):  
Jörg Prietzel ◽  
Wantana Klysubun
Keyword(s):  
Linear Combination ◽  
Xanes Spectroscopy ◽  
Organic P ◽  
Iron Oxyhydroxide ◽  
Edge Structure ◽  
X Ray ◽  
Soil P ◽  
P Sorption ◽  
Fe Oxyhydroxides ◽  
X Ray Absorption

Phosphorus (P) K-edge X-ray absorption near-edge structure (XANES) spectra of orthophosphate (oPO4) bound to soil FeIII minerals (e.g. ferrihydrite, goethite) show a pre-edge signal at 2148–2152 eV. It is unknown whether organic P bound to FeIII oxyhydroxides also show this feature. Otherwise, Fe-bound soil P may be underestimated by P K-edge XANES spectroscopy, because a large portion of Fe oxyhydroxide-bound P in soils is organic P. K-edge XANES spectra were obtained for different organic P compounds present in soils [inositol hexaphosphate (IHP), glucose-6-phosphate (G6P), adenosine triphosphate (ATP)] after sorption to ferrihydrite or goethite and compared with spectra of oPO4 adsorbed to these minerals. P sorption to ferrihydrite increased in the sequence IHP ≪ G6P < oPO4 < ATP. P sorption to goethite increased in the sequence G6P < oPO4 ≪ ATP = IHP. Pre-edge signals in P K-edge XANES spectra of organic P adsorbed to Fe oxyhydroxides were markedly smaller compared with those of oPO4 adsorbed to these minerals and absent for FeIII oxyhydroxide-bound ATP as well as goethite-bound IHP. Linear combination fitting (LCF) performed on spectra of IHP, G6P or ATP adsorbed to ferrihydrite or goethite, using only spectra of FeIII oxyhydroxide-bound oPO4 as reference compounds for Fe-bound P, erroneously assigned >93% (ferrihydrite) or >41% (goethite) of Fe-bound P to non-Fe-bound P species. Inclusion of FeIII oxyhydroxide-bound IHP as reference compounds markedly increased the recovery of oxyhydroxide-bound organic P. Thus, Fe-bound soil P has probably often been underestimated by LCF in soil XANES studies where IHP adsorbed to ferrihydrite and to goethite were not included as reference compounds.

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