Bibliothek

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Artikel: DFG Deutsche Nationallizenzen  (7)
  • Chemistry  (5)
  • Hydrophobic parameter  (2)
  • 1
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Reversed stationary phases ; Hydrophobic parameter ; Water/methanol eluent mixtures
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The hydrophobic retention characteristics of stationary ligands for reversed-phase high-performance liquid chromatography have been evaluated from the slope (r-value) of the plots relating the capacity factors (log k′) of selected aliphatic and aromatic compounds with the reciprocal of methanol concentration (log (1/[MeOH])) in aqueous mobile phase. Octadecylsilyl (ODS), trimethylsilyl (TMS) and phenyldimethylsilyl (phenyl) groups were selected as the stationary ligands bonded to silica support. On ODS or TMS silicas, unlike on phenyl silica, aliphatic compounds gave slightly larger r-values than aromatic compounds, indicating that the shape of the ligand recognizes the hydrophobic surfaces of aliphatic and aromatic solute molecules. On TMS and phenyl silicas, the degree of solute hydrophobicity contributing to its retention is about 90% and 85% of that on ODS silica, respectively. On the other hand, on TMS and phenyl silicas, the polar functional group on the solute molecule brought about a smaller decrease in retention than on ODS silica.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Hydrophobic parameter ; Capacity factor variation ; Organic modifier concentration ; Displacement model
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The dependence of the capacity factor (k′) on the concentration of the organic modifier (D) in the aqueous binary mobile phase in reversed-phase high-performance liquid chromatography has been investigated to evaluate the hydrophobicity of the solute molecule. The r-values, defined as the slope of log k′ vs. log(1/D) plots, were measured for various solutes and related to the non-polar surface area and the partition coefficients. The r-value was found to be a good indication of solute hydrophobicity. Detailed investigation of the results allowed to consider statistically the molecular posture of the solute adsorbed onto the stationary alkyl ligand.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 55 (1995), S. 343-349 
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: The shifts in membrane potential, caused by the injection of some amino acids into a permeation cell, were measured using immoblized γ-globulin membranes. The shifts in membrane potential were observed to be positive or negative when the isoelectric point of each amino acid injected into the cell was less or higher than 6.0. The potential response caused by the injection of each amino acid shows an individual and characteristic curve depending on the amino acid, and the difference in potential curves between D-aspartic acid and L-aspartic acid is significantly observed in the immobilized γ-globulin membranes. The t3/4 value was found to increase in the following order: lysine = glutamic acid 〈arginine 〈 D-aspartic acid = asparagine 〈 L-aspartic acid 〈 histidine 〈 alanine, where t3/4 indicates the time at which 75% of the shifts in membrane potential has been observed. The modified membrane potential theory provides satisfactory explanations for the membrane potential obtained experimentally before and after the injection of L-alanine, and the theoretical shifts can explain the experimental shifts in membrane potential due to the injection of L-alanine into the cell. © 1995 John Wiley & Sons, Inc.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 54 (1994), S. 1207-1217 
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: The bromination of poly(1-trimethylsilyl-1-propyne) (PMSP) was carried out by immersing a PMSP membrane in bromine water at 25°C. The bromine mainly reacted at the carbon-carbon double bonds in the backbone chain, and carbon-carbon single bonds were produced, which was determined from the infrared (IR) and ultravilet (UV)-visible analyses. The glass transition temperature of the PMSP is above 350°C, but a new endothermic peak appeared between 50 and 80°C in the differential scanning calorimetry (DSC) curves of all brominated PMSPs. The permeability for 12 gases in the PMSP membrane and its brominated membranes was investigated between 30 and 90°C below 1 atm. With increasing bromine content in the membrane, the permeability coefficient for all gases decreased together with the diffusion coefficient, and the ideal separation factor for the industrially important gas pairs increased at 30°C. A distinct change in slopes at near the endothermic temperature determined by the DSC analysis was observed in Arrhenius plots of the permeability coefficients in all brominated PMSP membranes. © 1994 John Wiley & Sons, Inc.
    Zusätzliches Material: 17 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 18 (1974), S. 1581-1583 
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 79 (1967), S. 530-531 
    ISSN: 0044-8249
    Schlagwort(e): Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    ISSN: 0570-0833
    Schlagwort(e): Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: No abstract.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...