Optimization of Supercritical Fluid Extraction of Essential Oil from Herba Moslae by Response Surface Methodology and Its Chemical Composition Analysis

摘要

Supercritical carbon dioxide extraction method was employed to extract the essential oil in Herba Moslae. The optimal conditions were determined by response surface methodology (RSM). Box-Behnken design was applied to evaluate the effects of three independent variables (temperature, pressure and extraction time) on the yield of the essential oil of Herba Moslae. The optimal conditions to obtain the highest yield of essential oil of Herba Moslae were determined as following values: 50℃ of temperature, 20MPa of pressure and 77 min of dynamic extraction time. Under these optimal conditions, the experimental results agreed with the predicted values obtained by using analysis of variance. This indicates a high goodness of fit of the model used and the success of response surface methodology. Furthermore, the chemical compositions of essential oil in Herba Moslae were analyzed by gas chromatography mass spectrometer (GC-MS). The results showed that thymol (41.87%), carvacrol (26.91%) and p-Cymene (9.27%) are the major constituents in the essential oil of Herba Moslae.