顶空固相微萃取-气相色谱/质谱法结合保留指数法测定龙井茶的香气成分

摘要

采用顶空固相微萃取(headspace solid phase micro-extraction,HS-SPME)和气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)结合保留指数法分析龙井中的挥发性成分.以茶叶香气成分的种类和数量为参照,考察HS-SPME的最佳萃取条件;同时优化色谱分离条件;利用优化的HS-SPME-GC/MS条件分析龙井茶中的挥发性成分.结果表明,运用HS-SPME-GC/MS能有效测定龙井茶中的挥发性成分,这些挥发性成分中主要含有醇类(31.14%)、酯类(15.66%)、酮类(10.42%)、杂环类化合物(15.00%)等.顶空固相微萃取-气相色谱质谱法结合保留指数分析是一种快速有效分析龙井茶香气成分的方法,可提高定性分析的准确性和效率,使定性结果更加可靠.该定性分析方法也为其他复杂样品中挥发性成分分析提供参考.%A headspace solid phase microextraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS) method combined with retention index was used to analyze aroma components from Longjing tea. The optimal extract conditions were evaluated according to the kinds and amounts of aroma compounds from Longjing tea, and the chromatographic separation conditions were also investigated. Under the optimal conditions, aroma components from Longjing tea were identified by mass spectral library searching combined with retention index comparison. The results showed that the HS-SPME-GC/MS method could identify aroma components from Longjing tea effectively,mainly including alcohols (31.14%), esters(15.66%), ketones(10.42%), and heterocyclic compounds(15.00%). This method is a fast, accurate, effective way to obtain aroma components from Longjing tea, which will facilitate qualitative analysis, and provide reference for analysis of volatile components from other complex samples.