POTENTIAL OF 3 DIFFERENT ALPHA-CYCLODEXTRIN MODIFICATIONS FOR THE GAS-CHROMATOGRAPHIC EVALUATION OF CONSTITUENTS OF VOLATILE OILS

Twenty-two typical constituents of volatile oils were studied by gas chromatography at 110 and 140 degrees C using capillaries of three different alpha-cyclodextrin modifications. The monotrifluoracetyl, dipentyl form gave the highest relative retention times against linalol for monoterpene carbonyls and hydrocarbons. It was used for the analysis of dill oil, containing such constituents, which is illustrated, with methofuran as a specific feature. The dipentyl (monohydroxy) derivative previously studied gave highest relative retention times for monoterpenols and ethers (including aromatics). The permethylated hydroxypropyl alpha-cyclodextrin tested as the most polar phase gave lowest values of the three modifications for most solutes except four alcohols and two others. It was otherwise non-discriminatory over structure, but gave best resolution of certain solute pairs, which emerge close together from some conventional phases.