Supercritical fluid extraction (SFE) of monoterpenes from the leaves of Melaleuca alternifolia (tea tree)

The technique of supercritical fluid extraction (SFE) was applied to variou s sample matrices under a range of supercritical carbon dioxide (scCO(2)) d ensities and chamber temperatures. The purpose was to develop an effective extraction condition for the removal of eight target monoterpenes from Aust ralian tea tree (Melaleuca alternifolia Cheel) leaves. The optimum conditio ns for extraction were found to be 0.25 g/mL scCO(2) density at a chamber t emperature of 110 degreesC. These condition were most effective when applie d to whole fresh and rehydrated whole dried leaves, where it yielded maximu m recovery of target analytes with minimum change in oil composition for th e extractor system employed. This study demonstrates the importance of the type of sample matrix used in SFE work, and that a different extraction pro tocol would need to be developed for each matrix.