Characterization and comparison of tea tree and lavender oils by using comprehensive gas chromatography

The essential oils from French lavender (Lavandula angustifolia) and tea tr ee (Melaleuca alternifolia) were separated by the two-dimensional GC techni que of comprehensive gas chromatography, A coupled column combination of no n-polar (5% phenyl equivalent) and polyethylene glycol phase columns was us ed to provide the desired resolution performance. By using a range of known standards, some of the peaks in lavender oil can be assigned. Some of thes e also occur in tea tree oil; however, from our knowledge of the major cons tituents in this oil and their relative retention behaviour, most of the ma jor peaks may be tentatively assigned within the 2-dimensional separation s pace. There appear to be elution patterns within the 2-D space which should be useful in correlating retention with chemical and structural properties of the components, although this will require further evaluation. A range of coeluting peaks, which may not he so readily separated by using a single column capillary GC analysis, are resolved in the experiment described.