Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1980-1984  (2)
  • 1983  (2)
  • Aromatic acids  (1)
  • Rekker's hydrophobic fragmental constant  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 17 (1983), S. 633-639 
    ISSN: 1612-1112
    Keywords: Macro porous polystyrene gel and the ion-exchange resins ; Aromatic acids ; Hydrophobicity ; Dissociation constant ; lon-pair
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The retention behaviour of aromatic acids was examined in a reversed-phase mode liquid chromatography. Macro porous styrene-divinylbenzene copolymers were selected on the basis of their chemical stability throughout the entire pH range. The effect of addition of a hydrophobic ion in the eluent and that of an ion-exchange group on the packing were discussed in relation with the hydrophobicity and the dissociation constant of solutes. The maximum capacity ratios of the acids on apolystyrene gel are linearly related with the hydrophobicity. The prediction of the retention time of aromatic acids could be possible by combination of their hydrophobicity and their dissociation constants.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 6 (1983), S. 20-26 
    ISSN: 0935-6304
    Keywords: Reversed-phase mode liquid chromatography ; Rekker's hydrophobic fragmental constant ; Calculation of concentration of organic modifier ; Prediction of retention time of phenols ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The chromatographic behavior of phenols in reversed-phase mode liquid chromatography differs from that of non-ionic compounds such as alkyl alcohols, alkylbenzenes, halogenated benzenes, polyaromatic hydrocarbons, and aromatic acids. Therefore, the retention times of 61 phenols were measured in a system of an octadecyl bonded silica gel and acetonitrile/water mixtures. The logarithm of the capacity ratio (log k') was found to be a linear function of the hydrophobicity (log P) in acidic acetonitrile/water mixtures. This result was applied to a different octadecyl bonded silica gel. Eight phenols were selected as standard compounds, and their log k' values were measured in 0.05 M phosphoric acid in 10 to 90% acetonitrile/water mixtures. An empirical polynomial relation was obtained between the concentration of acetonitrile and the slope of the log k' vs log P curve. Finally the capacity ratio of all phenols were calculated in given eluents by the equations derived from the measurements of standard compounds and the calculated log P values. The difference between predicted capacity ratios and measured ones was within 10%.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...