关键词: 乌龙茶, 顶空进样法, 气相色谱-质谱, 正交试验, 最优萃取条件, 挥发性成分

Abstract: The purpose of this experiment is to establish a rapid method for the determination and analysis of volatiles in Oolong tea represented by Jin Guanyin by static headspace gas chromatography/mass spectrometry (HS-GC/MS).Using L₉（3⁴）orthogonal test combined with single factor test and taking the peak number and peak area as indexes,we obtained the optimum extraction conditions of 4 kinds of factors,include headspace equilibrium temperature,equilibrium time,tea/NaCl and sample dosage.In the end,the volatile components of Jin Guan Yin were analyzed by this method.The results showed that the equilibrium temperature had the greatest influence on the number of peaks and the total peak area,while the equilibrium time had the least influence.The optimum conditions of headspace sampling were as follows:equilibrium temperature was 80 ℃,equilibrium time was 60 min,tea/NaCl was 1∶2,and the sample dosage was 0.5 g.We gained 104 kind of components in the extraction conditions,which can better reflect the chemical composition of Jin Guan Yin’s aroma and provide valuable data for the development and utilization of Oolong tea represented by Jin Guan Yin.

Key words: Oolong tea, headspace sampling, gas chromatography-mass spectrometry, orthogonal test, optimum extraction conditions, volatile components