Gas chromatography on a self-associating component of a binary phase. Retention model by formal analogy with conductance of electrolytes in dilute solution

Autor: Katsunori Watabe, Emanuel Gil-Av, Teresa Kowalska, Toshiyuki Hobo
Rok vydání: 1995
Předmět:
Zdroj: Chromatographia. 41:221-226
ISSN: 1612-1112
0009-5893
DOI: 10.1007/bf02267959
Popis: The dependence of specific retention by a binary stationary phase in GC can be expressed as the sum of the products of the specific retention of the pure components times their respective volume fractions. In this study, however, one component has a site, which is not only mainly responsible for the selectivity, but also participates in strong self-association. This requires introduction of a concentration-dependent factor (μx) in the corresponding term of the equation correlating Vg mix x with x. In the GC resolution of N-trifluoroacetyl-amino acid isopropyl esters on a binary phase, N-lauroyl-L-amino t-butyl amide-squalane, data for the values of μx were obtained. Adapting a previously developed LC retention model to the above GC data, an equation was derived for the dependence of μx on the weight fraction (x) of the selector, namely μx=√1/x. This relationship permits calculation of retention volumes on the binary phase for a given x, as well as corresponding resolution coefficients of enantiomeric amino acid derivatives with generally excellent agreement with experiment. The chirality of the system is not relevant to application of the equation.
Databáze: OpenAIRE
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