A comparative study of the ability of different techniques to extract menthol from Mentha piperita.

Supercritical fluid extraction, direct thermal desorption, hydroalcoholic extraction, and atomization are used to extract menthol from leaf plants of Mentha piperita. The investigated methods are comparatively evaluated on the basis of their reliability to determine the enantiomeric distribution of menthol. The enantioselectivity required for the gas chromatographic analysis is achieved using Octakis (2,6-di-O-n-pentyl-3-O-butyryl)-gamma-cyclodextrin as the stationary phase. From the obtained results, it is established that there is a significant effect of the combination of pressure and temperature to achieve the effective isolation and fractionation of the less and most volatile compounds using supercritical fluids.