Study On Extraction Of The Volatile Oil From Schizonepeta Tenuifolia Briq.

This thesis uses supercritical CO₂ extraction and microwave assisted extraction with the volatile oil rate of Schizonepeta tenuifolia Briq. as the goal. Following three parts are included in the thesis:Partâ… : In the supercritical CO₂ extraction, following four parts are included:1. The influences of cosolvent, extraction pressure, extraction temperature, extraction time, CO₂ flow rate on the extraction of volatile oil rate were discussed, and through the orthogonal experiment,the best extraction conditions of the volatile oil from Schizonepeta tenuifolia Briq. have been obtained: extraction pressure 25MPa, extraction temperature 45℃, extraction time 100min, CO₂ flow rate 30kg/h, and the extraction rate of volatile oil is 1.3014%.2. The main effective components of the volatile oil from Schizonepeta tenuifolia Briq. by GC-MS are pulegone and menthone. In addition, dihydrojasmone and terrein that had never been reported in literature have been identified.3. In order to research the solubility of volatile oil from Schizonepeta tenuifolia Briq. in SCCO₂, Chrastil solubility equation c = d^k exp(a/T+b) was used .The. d (density of supercritical CO₂ ) by using the P-R equation editing through the Newton method has been solved,and linear regression was performed on the experimental data corresponding to the equilibrium-controlled phase of each extract curve to get the c (volatile oil solubility in SCCO₂). All constants (a,b,k) of Chrastil solubility equation were determined, and the solubility equation of volatile oil from Schizonepeta tenuifolia Briq. in SCCO₂ was obtained: c=d^1.3947exp(737.252/T-15.859). The calculated values by the Chrastil equation were compared with experimental data. Through this equation, the solubility of volatile oil from Schizonepeta tenuifolia Briq. in SCCO₂ can be understood and forecasted.4. The research on the volatile oil from Schizonepeta tenuifolia Briq. by using two-stage separations indicates that, the content of total ketones compound by one stage separation is 12.14%, far lower than 54.95% by two-stage separations, and the content of pulegone and menthone increases from 3.37% and 3.46% by one-stage separation to 19.34% and 22.95% by two-stage separations respectively. But the content of the long chain unsaturated fatty acid and its ester ingredient reduces from 41.58% and 18.88% by one stage separation method to 29.06% and 9.86% by two-stage separations method respectively, also the phenol compound by two-stage separations method can been separated completely.Partâ…¡: In the microwave assisted extraction, following two parts are included:1. The influences of extraction solvent, microwave power, microwave radiation time, soaking time of raw material, and smashing granularity on the extraction rate of volatile oil from Schizonepeta tenuifolia Briq. have been discussed, and the best conditions through the orthogonal experiment have been obtained: Microwave radiation time 20min, microwave power 450W, soaking time 1h. Under which the extraction rate of volatile oil is 0.9652%. 2. The main effective components of the volatile oil by GC-MS are pulegone and menthone. In addition, 1-eicosanol that had never been reported in literature have been identified.Partâ…¢: the comparison of extraction methods of the volatile oil from Schizonepeta tenuifolia Briq. indicates that, in the case of extraction time, extraction color, the extract smell, character, rate, and so on, modern methods SFE and MAE are superior to the traditional methods SD and SE.