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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 36 (1993), S. 147-151 
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Polarity ; Retinoids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The retention of retinoids in reversed-phase liquid chromatography was studied using aqueous mobile phases of different composition (methanol 94–86% and acetonityrile 92–82%) at five temperatures (40–60 °C). With both organic modifiers the effect of the molecular structure increased as the water content and the polarity of the mobile phase increased. The temperature-dependence increased in the same manner with aqueous acetonitrile mobile phases. The π-π interactions between the retinoids and acetonitrile diminish when the water content of the mobile phase is increased, as happens also to the hydrophobic interactions with both organic modifiers. The net effect of these changes depends on the composition of the mobile phase. There was excellent correlation of retention with all polarity parameters studied(ϕ, P′, xe, xd, xn, E T N , δT, δ, δo and δd), when the calculations were made separately with methanol and acetonitrile. The volume fraction of the organic modifier, ϕ, was the only parameter describing the retention well in both organic modifiers simultaneously.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 37 (1993), S. 501-504 
    ISSN: 1612-1112
    Keywords: π-π interactions ; Mobile phase effects ; Phenyl stationary phase ; Retinoids ; Temperature effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The retention behaviour of retinoids, which are π-electron containing solutes, on a phenyl stationary phase was studied using mobile phases consisting of aqueous methanol (MeOH; 76–84 % v/v) and acetonitrile (ACN; 60–82% v/v) at five temperatures (40–60°C). Retention was increasingly affected in both mobile phases by temperature and molecular structure with increasing water content. The effects of mobile-phase are stronger in MeOH and highly aqueous ACN, retention is enhanced. The π-π interactions have a significant effect on the selectivity of chromatographic separations when the sample compounds differ in their electron donor/acceptor capacities.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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