Abstract: The present research aimed to analyze and compare the chemical composition of volatile oils from five batches of galangal (the rhizome of Alpinia officinarum Hance) with different ages grown in Xuwen, Zhanjiang, Guandong province. The volatile oils were obtained by steam distillation and analyzed by gas chromatography-mass spectrometry (GC-MS), and their compounds were identified according to their retention indices and quantified by peak area normalization. The results showed that the chemical constituents of all volatile oils were found to be broadly similar. The content of the indicator constituent, 1,8-cineole, was almost consistent among these samples. The contents of terpenoids and oxide compounds?continuously increased in 1 to 4 year-old galangal but declined in 5-year-old galangal. The contents of alcohols were increased in 1 to 3 year-old galangal but decreased gradually in 4 to 5 year-old galangal. The contents of ketones, esters and aldehydes kept on rising year by year. The chemical composition of volatile oils from Xuwen grown galangal was stable and the one from 4-year-old galangal had the best quality. Earlier or later harvesting of galangal deteriorated the quality of volatile oil. Furthermore, the fingerprint was established by choosing 25 main characteristic constituents. The fingerprint was validated on three batches of commercial galangal samples and showed good performances in terms of stability, similarity and repeatability. The above results will provide the foundation for optimal harvest time and quality control of galangal.

Key words: Alpiniae officinarum, different ages, volatile compounds, gas chromatography-mass spectrometry (GC-MS), retention index (RI)