A coupling between column liquid chromatography (LC) and atomic fluorescence spectrometry was developed for arsenic speciation. After separation, the compounds are oxidised on-line by UV irradiation, volatilised by hydride-generation and carried to the detector by a stream of argon. A combination of anion-exchange and hydrophobic interactions in a single column (Dionex AS7) was found suitable for the simultaneous separation of organic and inorganic species. Twelve compounds (arsenite, arsenate, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, arsenocholine, trimethylarsine oxide, tetramethylarsonium ion and four arsenosugars) were separated using an acetate buffer and a nitric acid solution as mobile phases. Limits of detection are 4-22 pg. The technique was applied to three marine samples. Arsenobetaine was detected as the main species in all samples, with concentrations varying from 59 to 1947 ng(As) g(-1) of fresh mass.
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http://dx.doi.org/10.1016/j.chroma.2003.09.068 | DOI Listing |
Sci Rep
December 2024
College of A&F Engineering and Planning, Tongren University, Tongren, 554300, China.
The Wanshan mercury mining area (WMMA) in Guizhou Province, China, has been identified as a region at high ecological risk owing to heavy metal contamination. This study employed non-lethal sampling methods, using the phalanges of Pelophylax nigromaculatus in the WMMA as analytical material. Ten heavy metal (metalloid) elements were selected for analysis, including Hg, Cr, Mn, Ni, Cu, Zn, Cd, Pb, As, and Se.
View Article and Find Full Text PDFRev Sci Instrum
December 2024
J-PARC Center, Japan Atomic Energy Agency, 2-4, Shirakata, Tokai-mura, Ibaraki, Japan.
A gas-sheet beam profile monitor enabling non-destructive two-dimensional profile measurements of a high-intensity beam by capturing an image of a beam-induced fluorescence was developed. For quantitative profile measurements, the monitor's response function comprising, e.g.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Institute of Biochemistry, Life Sciences Center, Vilnius University, Saulėtekio av. 7, Vilnius, LT-10257, Lithuania.
Neuronal cell death induced by cell membrane damage is one of the major hallmarks of neurodegenerative diseases. Neuroinflammation precedes the loss of neurons; however, whether and how inflammation-related proteins contribute to the loss of membrane integrity remains unknown. We employed a range of biophysical tools, including high-speed atomic force microscopy, fluorescence spectroscopy, and electrochemical impedance spectroscopy, to ascertain whether the pro-inflammatory protein S100A8 induces alterations in biomimetic lipid membranes upon interaction.
View Article and Find Full Text PDFPhotochem Photobiol
December 2024
Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil.
Pyranoflavylium cations are synthetic analogues of pyranoanthocyanins, the much more color-stable compounds that are formed spontaneously from grape anthocyanins during the maturation of red wines. In the present work, our studies of the photophysical properties of pyranoanthocyanin analogues are extended to include nine pyranoflavylium cations substituted with one or two bromo and/or iodo heavy atoms. The room temperature fluorescence, 77 K fluorescence and phosphorescence, triplet formation in solution, and sensitized singlet oxygen formation, with excited state acidity suppressed by the addition of trifluoroacetic acid, are compared to those of similar pyranoflavylium cations that do not contain a heavy atom.
View Article and Find Full Text PDFChem Sci
December 2024
Institute of Advanced Materials, Wroclaw University of Science and Technology Wrocław Poland
Near-infrared (NIR) emitters with high two-photon absorption (2PA) cross-sections are of interest to enable imaging in the tissue transparency windows. This study explores the potential of DNA-stabilized silver nanoclusters (Ag -DNAs) as water-soluble two-photon absorbers. We investigate 2PA of four different atomically precise Ag -DNA species with far-red to NIR emission and varying nanocluster and ligand compositions.
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