In the presence of Al(III) ions, 5-hydroxyflavone (5HF) through a complexation reaction in MeOH, shows dual fluorescence, characterized by a newly developed peak at 554nm upon excitation at 363nm. In this communication, the subsequent ligand exchange reaction of the complex with fluoride ion causing a fluorescence enhancement followed by a decrease in fluorescence intensity involving an intermediate mechanistic pathway, delivering a quantitative estimation route for fluoride ion in the concentration range from 5x10(-5) to 7x10(-4)M, has been reported. The ligand exchange reaction, without interference from other common anions, has been investigated by UV-vis and fluorescence spectroscopies combined with the AM1 semi-empirical self-consistent field quantum chemical calculations within UHF formalism in their ground state.
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http://dx.doi.org/10.1016/j.saa.2007.04.018 | DOI Listing |
Toxics
December 2024
Ufa Institute of Biology, Subdivision of the Ufa Federal Research Centre of the Russian Academy of Sciences, 450054 Ufa, Russia.
Bacteria of the genus are the most studied microorganisms that biodegrade persistent perfluoroorganic pollutants, and the research of their application for the remediation of environmental sites using biotechnological approaches remains relevant. The aim of this study was to investigate the ability of a known destructor of perfluorooctane sulfonic acid from the genus to accelerate and enhance the destruction of long-chain perfluorocarboxylic acids (PFCAs), specifically perfluorooctanoic acid and perfluorononanoic acid, in water and soil in association with the strain . 5(3), which has previously confirmed genetic potential for the degrading of PFCAs.
View Article and Find Full Text PDFPharmaceuticals (Basel)
December 2024
N. P. Bechtereva Institute of the Human Brain, Russian Academy of Sciences, 197022 St. Petersburg, Russia.
-succinimidyl-[F]fluorobenzoate ([F]SFB) is commonly prepared through a three-step procedure starting from [F]fluoride ion. A number of methods for the single-step radiosynthesis of [F]SFB have been introduced recently, including the radiofluorination of diaryliodonium salts and the Cu-mediated F-fluorination of pinacol aryl boronates and aryl tributyl stannanes, but they still have the drawbacks of lengthy product purification procedures. In the present work, two approaches for the direct labeling of [F]SFB from diaryliodonium (DAI) salt () and pinacol aryl boronate () are evaluated, with a major focus on developing a fast and simple SPE-based purification procedure.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
European Commission, Joint Research Centre (JRC), 76125 Karlsruhe, Germany.
This work presents the synthesis, purification, and characterization of a molten salt fuel for the irradiation experiment SALIENT-03 (SALt Irradiation ExperimeNT), a collaborative effort between the Nuclear Research and Consultancy Group and the Joint Research Centre, European Commission. The primary objective of the project is to investigate the corrosion behavior of selected Ni-alloy based structural materials which are being considered for the construction of fluoride molten salt reactors. During the test, these materials will be exposed to selected liquid molten fuel salts under irradiation in the High Flux Reactor in Petten, the Netherlands.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Department of Dentistry, Federal University of Maranhão (UFMA), São Luís 65080-805, MA, Brazil.
This in vitro study evaluated the effects of brushing with activated charcoal powder or toothpaste on enamel surface properties, including color change (ΔE), Knoop microhardness (HK), roughness (Ra), and the characteristics of the resulting brushing slurry [pH, fluoride (F), and calcium (Ca) concentration]. A total of 48 enamel samples were stained and divided into 4 groups ( = 12): activated charcoal toothpaste (AC-T), activated charcoal powder (AC-P), hydrogen peroxide-based whitening toothpaste (HP-T), and conventional toothpaste (C-T, positive control). The samples were subjected to a brushing cycling model, and ΔE, HK, Ra and enamel morphology were analyzed at baseline (T0) and after brushing cycle (T1).
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Laboratory of Metallurgy, School of Mining and Metallurgical Engineering, National Technical University of Athens, Iroon Polytechniou 9 Str., Zografou Campus, 15773 Athens, Greece.
This paper investigates the elution behavior of scandium from DEHPA (Di-(2-ethylhexyl) phosphoric acid)-impregnated resins that proceed with metal loading from acidic chloride solutions. DEHPA resins stem from their recognized selectivity for Sc extraction from acidic solutions. This study focuses on the elution process after ion-exchange extraction and examines various elution systems to achieve selective Sc recovery.
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