A clean-up method for polybrominated dibenzo-p-dioxins (PBDDs), dibenzofurans (PBDFs) and diphenyl ethers (PBDEs) was modified using combinations of multi-layered silica gel, Florisil and active carbon columns. By using active carbon column chromatography in the final procedure, PBDEs were well separated from PBDD/Fs in an elution test with reference standards. We report the application of this method to sediment samples taken from industrialized areas in Japan. These sediments contained PBDEs ranging in concentration from 13 to 2394 pg/g, dry wt. PBDEs did not interfere with the quantification of PBDD/Fs. In addition, PBDEs found in the PBDD/F fraction did not interfere with the identification of PBDFs using the HRGC/HRMS separation method. Some 2,3,7,8-tetra- to hexabrominated dioxins and furans were also detected in the sediment samples.
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http://dx.doi.org/10.1016/s0045-6535(03)00534-4 | DOI Listing |
Org Lett
January 2025
Department of Chemistry, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001, India.
A ruthenium-catalyzed intramolecular cascade cyclization of allene-alkyne has been achieved. This method offers a streamlined and atom-economical approach for the construction of sulfone bearing 1-cyclopenta[]naphthalenes, an important structural scaffold that exists in biologically active compounds. Our approach, backed by mechanistic insights from deuterium labeling, DFT calculations, and potential for reaction scale-up, presents synthetic chemists with an invaluable tool for efficiently producing a distinct carbon framework in a one-pot manner.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Graphene Composite Research Center, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, P. R. China.
In this study, a distinctive multiple core-shell structure of Co nanoparticles inserted into N-doped carbon dodecahedron@Co hydroxide (Co/NCD@Co(OH)) was synthesized a spontaneous redox reaction between metallic Co and NO, ultimately materializing the fine dispersion and exposure of the active sites. The electronic interaction existing between the Co/NCD core and the Co(OH) shell brings a synergistic effect, conspicuously lessens the overpotential, and reinforces the yield-rate and faradaic efficiency of NH for electrochemical nitrate-ammonia conversion. This study underlines the spontaneous redox between the catalysts and substrate, rendering it as a synthetic strategy for designing genuine and well-dispersed active sites.
View Article and Find Full Text PDFChemphyschem
January 2025
School of Energy and Power, New Energy, 02 Mengxi Street, 212003, Zhenjiang, CHINA.
Since hydrogen is a promising alternative to fossil fuels due to its high energy density and environmental friendliness, water electrolysis for hydrogen production has received widespread attentions wherein the development of active and stable catalytic materials is a key research direction. This article designs a dual transition metal doped functional graphene for hydrogen evolution reaction via density functional theory calculations. Among varied combinations, 16 candidates are screened out that are expected to be stable as reflected by the criterion of formation energy Ef < 0 and active due to its free energy of hydrogen adsorption ∆GH within the window of ±0.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Harbin Institute of Technology, School of Chemistry and Chemical Engineering, No. 92, West Dazhi Street, 150001, Harbin, CHINA.
Commercial hard carbon (HC) anode suffers from unexpected interphase chemistry rooted in the parasitic reactions between surface oxygen-functional groups and ester-based electrolytes. Herein, an innovative strategy is proposed to regulate interphase chemistry by tailoring targeted functional groups on the HC surface, where highly active undesirable oxygen-functional groups are skillfully converted into a Si-O-Si molecular layer favorable for anchoring anions. Then, an inorganic/organic hybrid solid electrolyte interphase with low interfacial charge transfer resistance and enhanced cycling durability is constructed successfully.
View Article and Find Full Text PDFMikrobiyol Bul
January 2025
Selçuk Üniversitesi Tıp Fakültesi, Tıbbi Mikrobiyoloji Anabilim Dalı, Konya.
Akut gastroenterit dünya genelinde en yaygın enfeksiyon hastalıklarından biridir. Bu hastalıklar gelişmekte olan ülkelerde çocuk ölümlerine ve ciddi ekonomik kayıplara neden olmuştur. Hastalık genellikle yaygın diyare şeklinde kendini gösterse de bazı olgularda şiddetli enfeksiyon belirtilerine, hatta ölümlere neden olmuştur.
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