Application of gas-liquid chromatography to the analysis of essential oils. Part VIII. Fingerprinting of essential oils by temperature-programmed gas-liquid chromatography using methyl silicone stationary phases

Abstract

Problems of obtaining reproducible results in the “fingerprinting” of essential oils by temperature-programmed gas-liquid chromatography have been examined and reported in Part VII of this series. That report was concerned both with the general problems and with the specific use of a polar stationary phase, i.e., Carbowax 20M. This report is concerned with the use of nonpolar stationary phases of the methyl silicone type and the application of the method of column standardisation described in Part VII.

A collaborative study with methyl silicone stationary phases and a specification of “g-pack values” for the column packing has resulted in the production of a method that yields reproducible relative retention indices for the test substances limonene, acetophenone, linalol, naphthalene, linalyl acetate and cinnamyl alcohol and has been applied with satisfactory results to oils of bergamot, Jamaican ginger, Nigerian ginger, West Indian nutmeg and East Indian nutmeg. A recommended method is given for the reproducible temperature-programmed gas-liquid chromatographic fingerprinting of essential oils when methyl silicone stationary phases are used.