目的 揭示降香挥发油水蒸气蒸馏过程中挥发性成分的提取、分布规律及影响因素。方法 采用水蒸气蒸馏法提取降香饮片挥发油，每30 min收集1次提取液，分离芳香水部分和挥发油部分，通过GC-MS分析不同时段提取液的化学成分。结果 实验共得136种挥发性成分，其中反式-橙花叔醇、（E）-β-famesene、α-farnesene为主要特征成分；水中特有成分22种、油中特有成分共计13种、油水共有成分有101种。水中特有成分与芳香水主要特征成分的溶出/扩散呈显著正相关，而与挥发油中主要成分呈负相关。水中特有成分的水溶解度最大，主成分分析（PCA）结果表明，PC1（熔点、表面张力、极性曲面、折射率呈负相关成分）、PC2（极化率、相对分子质量、沸点呈正相关成分、水溶解度呈负相关成分）是导致成分分布差异的主成分。结论 水蒸气蒸馏法提取降香挥发油过程中，挥发性成分受自身理化性质的影响，部分成分特异性地在芳香水、挥发油体系分布，水中特有成分增加了主要成分在芳香水中的含量，可能是导致挥发油提取过程易产生"乳化"现象进而导致挥发油品质下降的重要原因。

Objective To reveal the extraction, distribution, and influencing factors of volatile components in the extraction process of Dalbergiae Odoriferae Lignum (DOL). Methods Volatile oil was extracted by steam distillation, and the extract was collected every 30 min to separate the aromatic water part and the volatile oil part, of which chemical composition was analyzed by GC-MS. Results A total of 136 volatile constituents were obtained, of which trans-nerolidol, (E)-β-famesene, and α-farnesene were the main characteristic constituents. A total of 22 kinds of components distributed only in water, 13 kinds only in oil and 101 kinds in both oil and water. The specific components in water were positively correlated with the dissolution/diffusion of the main characteristic components in aromatic water, while negatively correlated with the main components in volatile oil. The water solubility of the unique components in water is the highest. The results of principal component analysis showed that PC1 (melting point, surface tension, polar surface, negative correlation of refractive index) and PC2 (polarizability, molecular weight, boiling point positive correlation, negative correlation of water solubility) were the principal components that lead to the difference of component distribution. Conclusion Affected by the physical and chemical properties of volatile component itself, some components specifically distributed in water which increased the content of main components in the aromatic water, resulting in volatile oil extraction process easy to "emulsification", in turn, leading to an important reason for the declining quality of volatile oil.

国家自然科学基金资助项目（81703720）；陕西省科技厅重点研发计划资助项目（2018SF-314）；陕西省教育厅资助项目（18JK0208）；陕西省中医药管理局中药制药工程重点学科资助项目（132018004）；陕西中医药大学校级项目（2017PY29）；陕西中医药大学学科创新团队建设项目（2019-YL11）