Supercritical Fluid Extraction (SFE) of Monoterpenes from the Leaves of Melaleuca alternifolia (Tea Tree)

The technique of supercritical fluid extraction (SFE) was applied to various sample matrices under a range of supercritical carbon dioxide (scCO2) densities and chamber temperatures. The purpose was to develop an effective extraction condition for the removal of eight target monoterpenes from Australian tea tree (Melaleuca alternifolia Cheel) leaves. The optimum conditions for extraction were found to be 0.25 g/mL scCO2 density at a chamber temperature of 110oC. These condition were most effective when applied to whole fresh and rehydrated whole dried leaves, where it yielded maximum recovery of target analytes with minimum change in oil composition for the extractor system employed. This study demonstrates the importance of the type of sample matrix used in SFE work, and that a different extraction protocol would need to be developed for each matrix.