GC-MS characterization of the compounds in some essential oils.

The composition of different essential oils (menthe , basil, lavender, rose) was investigated by gas chromatographic-mass spectrometry (GC-MS) method to identify those compounds responsible for the characteristic, pleas ant floral or aroma odour or taste of some valuable oils. Three different rose oils presented monoterpe nes as fragrance target compounds and some aliphatic hydrocarbons with fixative effects respon sible for a longer-lasting odour impression. Chromatography was performed on a 5% phenyl methylpolysiloxane column (15 or 30 m x 0.25 mm I.D., 0.25 µm) operated in suitable temperature pro grams.