Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Enantioselective gas chromatography with functionalized cyclodextrins as chiral selectors. Fundamentals of the measurement of absolute association constants using capillary columns
Ist Teil von
Journal of Chromatography A, 2016-10, Vol.1467, p.482-489
Ort / Verlag
Netherlands: Elsevier B.V
Erscheinungsjahr
2016
Quelle
Access via ScienceDirect (Elsevier)
Beschreibungen/Notizen
•We propose a reliable GC method for determining enantiomeric association constants.•Capillary GC columns with a g-CD derivative as a chiral selector were constructed.•Absolute association constants of amino acid derivatives with a g-CD were obtained.•True enantioselectivity and apparent enantioselectivity are critically discussed.
Chiral capillary GC columns containing different amounts of octakis(6-O-tert-butyldimethylsilyl-2,3-di-O-acetil)-γ-cyclodextrin as chiral selector dissolved in a polymeric matrix were constructed with the aim of determining enantiomeric association constants between a group of well resolved chiral N-trifluoroacetyl amino acid methyl esters and this specific selector at different temperatures. The most relevant sources of uncertainties in the experimental data (hold-up and retention times, and column phase ratios at each temperature) were assessed. These cyclodextrin-based columns are known to enantioseparate a wide variety of chemical compounds, thus, the measurement of the absolute enantioselective constants of a group of solutes with this selector can be useful for systematic studies aimed to a general understanding about how these selectors work. These absolute association constants were estimated from data collected from very simplified experimental systems, and by using the fundamental gas-liquid chromatography equations.