Extrapolation of isothermal retention data in gas chromatography for chiral recognition studies

Koppenhoefer, Bernhard; Abdalla, S.; Hummel, Michael

doi:10.1007/bf02290493

Cited by 6 publications

(2 citation statements)

References 32 publications

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“…Calibration and test of the apparatus as well as the measuring procedure were described elsewhere. [8][9][10][11][12][13][14][15][16][17][18][19] The liquid mixtures to be studied were made up by adding successively weighed amounts of a pure enantiomer to a given amount of the other (in the order of 2-3 g). At least eight measurements were carried out in two runs for each system examined, starting from one isomer and then from the other.…”

Section: Methodsmentioning

confidence: 99%

Chiral Discrimination in the Liquid Phase: Excess Volumes of Binary Mixtures of Amino Acid Derivatives

Lepori¹,

Koppenhoefer²

1994

J. Phys. Chem.

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Volume changes on mixing the enantiomers of N-trifluoroacetylamino acid methyl esters (N-TFA-amino acidOMe) were determined at 25 OC by means of a high-precision vibrating-tube densimeter. The excess molar volumes (Ve) for the racemic mixtures of N-TFA-Ala-OMe 1, N-TFA-Val-OMe 2, and N-TFA-Leu-OMe 3, were found as Ve = 0.0098, -0.0458, and 0.035 cm3 mol-', respectively. For 2 and 3, these volumetric effects of discriminating interactions between enantiomers in the liquid phase are the largest ever observed.

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Section: Methodsmentioning

confidence: 99%

Chiral Discrimination in the Liquid Phase: Excess Volumes of Binary Mixtures of Amino Acid Derivatives

Lepori¹,

Koppenhoefer²

1994

J. Phys. Chem.

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“…s(AH)). The data were calculated according to thk equations given by Koppenhoefer et al [15], who, due to a smaller curvature of the plots, found smaller relative errors for chiral diamide phases than those obtained by us with cyclodextrin derivatives. This is an indication that the enantioselective interactions of a solute are more complex with cyclodextrin phases than with chiral diamide phases.…”

Section: Figure 3 Plot Of Separation Factor and Plate Height (Van Dementioning

confidence: 99%

Diluted versus undiluted cyclodextrin derivates in capillary gas chromatography and the effect of linear carrier gas velocity, column temperature, and length on enantiomer separation

Hardt

König

1993

J Microcolumn Separations

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Abstract. The effect of dilution of the chiral stationary phase octakis(3-O-butyryl-2,6-di-0-penty1)-y-cyclodextrin in the achiral polysiloxane OV-1701 on the separation factor was investigated over a wide concentration range. The loss in enantioselectivity was only negligible down to a dilution of 50 % (w/w), since the separation factor vs. concentration curves levels off at higher concentrations. Because of the strong temperature dependence of the separation factors, the properties of short columns (10 m and 4.5 m) were evaluated. These short columns, which allow operation at low temperatures and lead to enhanced separation factors were found to be appropriate for the separations of simple mixtures, because the gain in selectivity exceeded the loss in separation efficiency. For complex mixtures, the higher efficiencies of columns of at least 25 m in length were still necessary. A plot of In 01 vs. 1/T did not yield straight lines, but showed a significant curvature, leading to considerable relative errors if thermodynamic data were derived from these plots.

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Gas chromatographic separation of the enantiomers of flumecinol and some related compounds

Reinhardt¹,

Engewald²,

Gǒrög³

1995

J. High Resol. Chromatogr.

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Key Words:Enantioselective GC Permethylated a-and P-cyclodextrin stationary phases Flumecinol(3-trifluoromethyl-a-ethylbenzhydrol) a-Ethylbenzhydrol derivatives SummaryFlumecinol and related compounds can, without derivatization, be separated into their enantiomers by gas chromatography on cyclodextrin phases; permethylated P-cyclodextrin dissolved in OV-1701 can be particularly recommended. Thermodynamic data describing the different intensities of interaction of the individual enantiomers with the stationary phases were determined. The values measured imply different separation mechanisms for the compounds investigated.

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Extrapolation of isothermal retention data in gas chromatography for chiral recognition studies

Cited by 6 publications

References 32 publications

Chiral Discrimination in the Liquid Phase: Excess Volumes of Binary Mixtures of Amino Acid Derivatives

Chiral Discrimination in the Liquid Phase: Excess Volumes of Binary Mixtures of Amino Acid Derivatives

Diluted versus undiluted cyclodextrin derivates in capillary gas chromatography and the effect of linear carrier gas velocity, column temperature, and length on enantiomer separation

Gas chromatographic separation of the enantiomers of flumecinol and some related compounds

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