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Current paleontological techniques to separate vertebrate fossils from encasing iron-rich cements by chemical means are limited by the low solubility of common iron(III) hydroxide oxides such as hematite and goethite. This study examines novel geochemical extractions capable of selectively dissolving iron(III) hydroxide oxides, in aqueous solutions of pH 9-11, without damaging fossilised bones or teeth (hydroxidecarbonate-apatite). This involves the siderophore ligands pyridoxal isonicotinoyl hydrazone (PIH), salicylaldehyde isonicotinoyl hydrazone (SIH), and acetohydroxamic acid (aHA), whose coordination complexes with iron(III) show exceptionally high formation stability constants. The methods have been tested on natural hematite and fossil containing samples from the Riversleigh World Heritage Area in Australia. Both 0.01 mol dm aHA and 0.001 mol dm PIH at pH 9.7 were able to dissolve over 0.1 mmol dm of the goethite coating bone fragments.
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http://dx.doi.org/10.1002/cplu.202000407 | DOI Listing |
ACS Appl Nano Mater
July 2025
Laboratory of Immunotherapy, Institute of Microbiology, Czech Academy of Sciences, Prague 142 00, Czech Republic.
Magnetic nanoparticles have been at the center of biomedical research for decades, primarily for their applications in magnetic resonance imaging (MRI) and magnetic particle imaging (MPI). Superparamagnetic particles, typically based on iron oxide crystals, are effective in both modalities, although each requires distinct magnetic properties for optimal performance. We investigated the performance of nanoparticles based on a nickel-substituted ferrite core and compared them to standard maghemite iron oxide nanoparticles.
View Article and Find Full Text PDFJ Phys Chem A
June 2025
Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
Recent research has identified a new photocatalytic mechanism that generates significant amounts of chlorine over the North Atlantic, involving iron from mineral dust, chloride from sea spray, and sunlight. While it is known that charge transfer absorption in iron chlorides (FeCl) reduces Fe to Fe and oxidizes Cl to neutral chlorine (Cl), important questions remain regarding the chemical state of iron before and after the reaction and the mechanism of chlorine release. Brines and solid precipitates form from iron, sodium, and chloride in atmospheric particles, and iron is distributed among hydrated Fe(II) and Fe(III) chlorides, oxides, and hydroxides, depending on the concentration, pH, and humidity.
View Article and Find Full Text PDFNanoscale
June 2025
Institute of Nano Science and Technology, Knowledge City, Sector-81, Mohali-140306, Punjab, India.
Integration of novel biocompatible nanostructures as effective sensing platforms is still of great significance for robust and rapid analysis. Herein, novel iron(III) metal-organic framework (Fe-MOF) nanospheres with the formula [Fe(μ-O)(COH)(COO)(HO)·2DMF] were successfully developed and characterized by single crystal X-ray diffraction (SXRD) studies. Interestingly, fluorescence studies reveal that Fe-MOF is an effective multi-functional turn-on sensor for nicotine and cotinine that exhibits a blue shift, a low detection limit, notable recyclability, and good anti-interference ability.
View Article and Find Full Text PDFRSC Adv
May 2025
Materials Science and Nanotechnology Department, Faculty of Postgraduate Studies for Advanced Sciences (PSAS), Beni-Suef University Beni-Suef Egypt
Green rust (GR), a mixed-valent iron mineral from the layered double hydroxides family, has gained attention for its potential in environmental and energy applications. Despite its widespread presence and possible role in life's evolution, GR's susceptibility to oxidation has limited its practical use. In this study, we prepared a stabilized GR, synthesized through a one-pot solvothermal method using iron(iii) chloride and glycerol.
View Article and Find Full Text PDFInt J Biol Macromol
May 2025
LEPAMAP-PRODIS Research Group, University of Girona, C. Maria Aurèlia Capmany, 61, 17003 Girona, Spain.
3,3',5,5'-tetramethylbenzidine (TMB), insoluble in water, is known to change color in the presence of strong oxidizers. Responsive aqueous dispersions of TMB were obtained with anionic cellulose nanofibers (CNFs) as the only stabilizing agent. A Pickering emulsion approach and the use of a miscible co-solvent were also explored, combining an aqueous CNF suspension with a solution of TMB in either chloroform or ethanol, respectively.
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