Chemical composition and comparison of theRehmannia glutinosaLibosch oil using steam distillation and solvent extraction

Steam distillation (SD) and solvent extraction (SE) using hexane, methylene chloride, and ethyl acetate were compared for their effectiveness in the oil extraction from Rehmannia glutinosa Libosch. The four oil samples extracted by both methods respectively were analyzed using GC-MS. The qualitative comparison showed that the number and total amount of compounds detected in hexane was higher than others. More high-volatile compounds were detected in SD extract than in SE extract. The first principal component separated the SD extract from other three SE samples based on the higher concentrations of high-volatile compounds.