| A gas chromatography-mass spectrometry(GC-MS) combined with retention index(RI) method was developed for the analysis of volatile oils in Rhizoma Alpiniae Officinarum extracted by steam distillation(SD),ultrasonic assisted solvent extraction(UAE) and subcritical fluid extraction(SFE).51,46 and 60 volatile components in the oils extracted by the three above-mentioned methods were identified,respectively.Meanwhile,each of them was quantified by area normalization method.The results indicated that the content of the index constituent,i.e.,1,8-cineole,the content by SD was similar to that by SFE,and higher than that by UAE.Although UAE was time-saving and less energy consumption,the oil quality was poorer due to the use of organic solvents hard to remove.In addition,some constituents could be gained by SFE but not by SD,such as 2-hydroxycineole,diarylheptanoids and etc.On one hand,the relative contents of high boiling components obtained by SFE,like β-caryophyllene,α-caryophyllene,α-farnesene and γ-cadinene,were higher than the others.On another hand,the relative contents of low boiling components obtained by SD,like α-pinene,camphene,β-pinene,limonene,camphor and α-terpineol,were the highest of three.In conclusion,volatile oil components by different extraction methods from the same batch of materials were proved broadly similar,but there were some differences in composition and component ratio.Therefore,development and utilization of different extraction methods must be selected according to the functional requirements of products. |