A novel branch-type diamide-embedded octadecyl stationary phase was prepared by facile amidation. The preparation of this new phase involves the synthesis of new bifunctional silane ligand and surface modification of spherical silica via anchoring of silane coupling agent. The obtained diamide-embedded octadecyl stationary phase demonstrated excellent hydrophobic selectivity, as well as enhanced shape and planarity selectivity in comparison to commercial polymeric and monomeric C18 phases, respectively, as revealed by the systematic investigation into its liquid chromatographic retention of isomeric polycyclic aromatic hydrocarbons. The applicability of this new stationary phase was further testified by the effective separation of isomeric compounds belong to different chemical classes, including chain isomers of alkylbenzenes, and positional isomers of substituted aromatics. An in-depth analysis of the separation mechanisms other than molecular shape recognition involved in the new stationary phase was performed using a linear solvation energy relationships model and compared with its monoamide and pure C18 counterparts correspondingly. The performance of the new stationary phase in quantitative analysis of phenols from real-world samples was also evaluated.
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http://dx.doi.org/10.1016/j.aca.2014.05.011 | DOI Listing |
Nat Microbiol
January 2025
Department of Chemistry, Indiana University, Bloomington, IN, USA.
To overtake competitors, microbes produce and secrete secondary metabolites that kill neighbouring cells and sequester nutrients. This metabolite-mediated competition probably evolved in complex microbial communities in the presence of viral pathogens. We therefore hypothesized that microbes secrete natural products that make competitors sensitive to phage infection.
View Article and Find Full Text PDFFood Res Int
January 2025
Center for Research and Development in Food Cryotechnology (CIDCA, CCT-CONICET), La Plata 1900, Argentina. Electronic address:
Layer-by-Layer (LbL) self-assembly encapsulation is a promising technology for the protection and delivery of lactic acid bacteria. However, laboratory-scale encapsulation is often time-consuming, involves intensive protocols tailored for small-scale operations, requires substantial amounts of energy and water, and results in a low yield of encapsulated biomass. Scaling-up this process to a bench-bioreactor scale is not simply a matter of increasing culture volume as different key parameters (not particularly relevant at lab scale) become critical, including biomass production, the number of polymer layers, and the biomass-to-polymer mass ratio.
View Article and Find Full Text PDFJ Chromatogr A
December 2024
HUN-REN Molecular Interactions in Separation Science Research Group, Ifjúság útja 6, H-7624 Pécs, Hungary; Department of Analytical and Environmental Chemistry and Szentágothai Research Center, University of Pécs, Ifjúság útja 6, H-7624 Pécs, Hungary; Institute of Bioanalysis, Medical Scool, University of Pécs, Szigeti út, H-7624 Pécs, Hungary. Electronic address:
Non-destructive chromatographic methods were used to determine the hold-up volumes of four self-packed columns containing embedded phosphate groups. The stationary phases are named Diol-P-C10, Diol-P-C18, Diol-P-Benzyl and Diol-P-Chol. The hydrophobicity of organic ligands bound to the phosphate group increases in the benzyl< decyl < octadecyl
Small
January 2025
Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi'an, 710127, China.
The development of monodisperse hybrid silica microspheres with highly regular pore structure and uniform distribution of functional groups have significant value in the biomolecular separation field. In this work, the short range ordered pore channels are precisely constructed onto the non-porous silica microsphere surface by a bi-phase assembly method, and the cylindrical silica channel introduced a plethora of vinyl groups by "one-pot" co-condensation to form vinyl hybrid silica shell. As hydrophilic interaction chromatography (HILIC) stationary phase, the vinyl hybrid core-shell silica microsphere is simply modified with zwitterion glutathione (SiO@SiO-GSH), in which the HILIC enrichment process is significantly shortened due to its specific porous characteristics.
View Article and Find Full Text PDFAnal Methods
January 2025
Department of Chemistry, Universidade Federal de Santa Catarina, Florianópolis, SC, 88035-972, Brazil.
A new analytical method was developed for the determination of 14 multiclass emerging organic contaminants in surface waters using LC-MS, and Dispersive Liquid-Liquid Microextraction (DLLME) for extraction. Different Natural Deep Eutectic Solvents (NADESs) composed of terpenes and organic acids were tested as extraction solvents and characterized by Fourier Transform Infrared Spectroscopy (FTIR), Hydrogen Nuclear Magnetic Resonance Spectroscopy (H-NMR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), density, and viscosity, eliminating the need to use traditional chlorinated solvents. NADES produced with butyric acid and thymol showed the best results and was selected for application for the first time in the extraction of emerging organic contaminants of different classes in water samples.
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