ABSTRACT
Objective: To systemically investigate the volatile organic compounds (VOCs) of Viola yedoensis, and to compare the VOCs differences of V. yedoensis obtained by the needle trap, static headspace and hydrostillation methods. Method: The needle trap, static headspace and hydrostillation methods coupled with gas chromatography-mass spectrometer (GC-MS) were developed for isolation and identification of the VOCs in V. yedoensis. The relative content of each component was obtained by peak area normalization with a triple-bed needle packed with Tenax, Carbopack X and Carboxen 1000 sorbents. Result: The 112 compounds were trapped by using needle trap, mainly moderate volatile components, including aldehydes, ketones, alcohols, monoterpenes, sesquiterpenoids and aromatic compounds. The static headspace and hydrodistillation methods were allowed to obtain 37 (mainly the high-volatile components) and 78 compounds (mainly low-volatile components), respectively. Only 13 common volatile components were detected in all these three methods. Conclusion: The results clearly demonstrated that the needle trap method is an alternative method for sampling VOCs of herbs, characterized by fast analysis, simple operation, good enrichment effect and high sensitivity.These three methods for VOCs analysis are complementary for each other.