Determination of essential oil in a traditional Chinese medicine, Fructus amomi by pressurized hot water extraction followed by liquid-phase microextraction and gas chromatography-mass spectrometry

In this paper, for the first time, two sample techniques of pressurized hot water extraction (PHWE) and liquid-phase microextraction (LPME) were combined and applied to the analysis of essential oil in a traditional Chinese medicine (TCM), Fructus amomi. Essential oil in E amomi samples (50.0 mg) were extracted by PHWE equipment in dynamic mode, followed by extraction and concentration with headspace (HS)-LPME and detection by gas chromatography-mass spectrometry (GC-MS). The PHWE and HS-LPME parameters were optimized and the method repeatability was studied. The three active compounds of camphor, bomeol and bomeol acetate in the E amomi sample from five different growing areas were quantitatively analyzed by internal standard method. Compared to steam distillation (SD), the proposed method required simple sample preparation, little sample mass and whole analysis time less than 40 min. The present method provided good repeatability (R.S.D. < 12.0%). It has been demonstrated that PHWE-LPME-GC-MS is a simple, rapid and low-cost method for determination of essential oils in TCMs and is a potential tool for TCM quality assessment. (c) 2004 Elsevier B.V. All rights reserved.