A module was developed for the continuous monitoring of volatile halogen organic pollutants in complex matrices. The module utilized a polymer membrane for extraction and a capillary gas chromatography-mass spectrometry (GC-MS) for detection. The extraction of analytes (CHCl(3), CHCl(2)Br, CHClBr(2) and CHBr(3)) from samples was performed in a flow system mediated by a non-porous flat membrane. The effects of the phase-volume ratios, flow conditions, kinetics, analyte properties and matrices were assessed and optimized. The limits of detection were at low microg L(-1) to ng L(-1) levels, with GC-MS analysis under selected ion monitoring (SIM), whereas enrichment factors between 6 and 30 were achieved. Precision values calculated as repeatability and reproducibility with a relative standard deviation (%RSD, n = 5) of 7.2 to 9.5 after 30 min were obtained. The performance of the continuous membrane assisted solvent extraction system was compared with classical liquid-liquid extraction. The method was applied to the extraction of trihalomethanes in chlorinated drinking-water samples.
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http://dx.doi.org/10.2116/analsci.25.419 | DOI Listing |
Phys Rev Lett
December 2024
CPT, CNRS, Aix Marseille Univ, Université de Toulon, (UMR 7332), Turing Center for Living Systems, Marseille, France.
Athermal (i.e., zero-temperature) underconstrained systems are typically floppy, but they can be rigidified by the application of external strain, which is theoretically well understood.
View Article and Find Full Text PDFmBio
January 2025
Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA.
The 55-carbon isoprenoid, undecaprenyl-phosphate (UndP), is a universal carrier lipid that ferries most glycans and glycopolymers across the cytoplasmic membrane in bacteria. In addition to peptidoglycan precursors, UndP transports O-antigen, capsule, wall teichoic acids, and sugar modifications. How this shared but limited lipid is distributed among competing pathways is just beginning to be elucidated.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Aramco Americas, Boston Research Center, Cambridge, MA, 02139, USA.
Membrane-based gas separation provides an energy-efficient approach for the simultaneous CO and HS removal from sour natural gas. The fluorinated polyimide (PI) membranes exhibited a promising balance between permeability and permselectivity for sour natural gas separation. To further improve the separation efficiency of fluorinated PI membranes, a melamine-copolymerization synthetic approach is devised that aims to incorporate melamine motifs with high sour gas affinity into the structure of the PI membranes.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
University of Science and Technology of China School of Biomedical Engineering, Department of Polymer Science and Engineering, 96 Jinzhai Road, 230026, Hefei, CHINA.
Lipid nanoparticles (LNPs) based messenger RNA (mRNA) therapeutics hold immense promise for treating a wide array of diseases, while their nonhepatic organs targeting and insufficient endosomal escape efficiency remain challenges. For LNPs, polyethylene glycol (PEG) lipids have a crucial role in stabilizing them in aqueous medium, but they severely hinder cellular uptake and reduce transfection efficiency. In this study, we designed ultrasound (US)-assisted fluorinated PEGylated LNPs (F-LNPs) to enhance spleen-targeted mRNA delivery and transfection.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Department of Process Engineering and Technology of Polymer and Carbon Materials, Wroclaw University of Science and Technology, Wyb. St. Wyspiańskiego 27, 50-370 Wrocław, Poland.
We investigate a continuous electrochemical pH-swing method to capture CO from a gas phase. The electrochemical cell consists of a single cation-exchange membrane (CEM) and a recirculation of a mixture of salt and phenazine-based redox-active molecules. In the absorption compartment, this solution is saturated by CO from a mixed gas phase at high pH.
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