薤白挥发油成分的超临界CO_2萃取及GC-MS分析

GC-MS analysis of the volatile oil from Bulbus Allii Macrostemonis extracted by supercritical carbon dioxide

采取超临界CO2萃取和水蒸气蒸馏两种方法提取薤白中的挥发油,比较了两种提取方法得到的挥发油的理化性质,并利用GC-MS对它们进行了定性、定量分析。两种方法的主要提取物均为含硫化合物,但超临界CO2萃取法得到的含硫化合物的数量和质量都高于水蒸气蒸馏法得到的提取物。采用水蒸气蒸馏法提取8 h得到的萃取率为1.72%。通过设计的超临界CO2萃取的正交实验,得到了最佳萃取工艺条件为:压力25 MPa,温度40℃,CO2流量为25L/h。最佳萃取时间为120 min,萃取率为4.41%,是水蒸气蒸馏法萃取率的2.8倍。实验结果表明,超临界CO2萃取法简单易行,可以较快速、有效地提取薤白中的挥发油。

The volatile oil in Bulbus Allii Macrostemonis were extracted by supercritical CO2 and stream distillation and analyzed qualitatively and relatively quantitatively by GC-MS. And physical and chemical properties of the volatile oils extracted with the two methods were compared. The main extractions of these two methods were all sulfur-containing compounds. But the sorts and mass of the sulfur-containing compounds extracted by supercritical CO2 were all more than those of the sulfur-containing compounds extracted by stream distillation. Under the temperature of 100 ℃, the extraction efficiency was 1.72% with 8-hour stream distillation. The effects of extraction pressure, temperature, flow rate of CO2 on the extraction efficiency were studied by supercritical CO2 extraction orthogonal experiment. The optimal conditions were determined： pressure 25 MPa, temperature 32 ℃ and CO2 flow rate 25 L/h. Under the above optimal conditions, the extraction time of 120 min was finally determined by some experiments. The volatile oil were obtained by supercritical CO2 and the extraction effiiency was 4.41%, as 2.8 times as that of stream distillation. The results showed that supercritical CO2 extraction can simply, more quickly and effectively extract the volatile oil in Bulbus Allii Macrostemonis. It is really an ideal method for extracting the volatile oil in Bulbus Allii Macrostemonis.