title: Enantioselective gas chromatography with functionalized cyclodextrins as chiral selectors. Fundamentals of the measurement of absolute association constants using capillary columns.
abstract: 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.
authors.affiliation: Laboratorio de Investigación y Desarrollo de Métodos Analíticos (LIDMA), Facultad de Ciencias Exactas, 49 y 115, 1900, Universidad Nacional de La Plata, Argentina.
authors.forename: Fiorella
authors.initials: F
authors.lastname: Menestrina
authors.affiliation: Laboratorio de Investigación y Desarrollo de Métodos Analíticos (LIDMA), Facultad de Ciencias Exactas, 49 y 115, 1900, Universidad Nacional de La Plata, Argentina.
authors.forename: Nicolás R
authors.initials: NR
authors.lastname: Ronco
authors.affiliation: Laboratorio de Investigación y Desarrollo de Métodos Analíticos (LIDMA), Facultad de Ciencias Exactas, 49 y 115, 1900, Universidad Nacional de La Plata, Argentina. Electronic address: castells@isis.unlp.edu.ar.
authors.forename: Cecilia B
authors.initials: CB
authors.lastname: Castells
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D002849:Chromatography, Gas / Q000379:methods; D003505:Cyclodextrins / Q000737:chemistry*; D019075:Electrophoresis, Capillary; D013237:Stereoisomerism; D013696:Temperature; D047408:gamma-Cyclodextrins / Q000737:chemistry
chemical_list: D000596:Amino Acids; D003505:Cyclodextrins; D047408:gamma-Cyclodextrins
keywords: Association constants; Capillary columns; Chiral gas-liquid chromatography; N-trifluoroacetyl amino acid methyl esters; Octakis(6-O-tert-butyldimethylsilyl-2,3-di-O-acetil)-γ-cyclodextrin