GC—TOF MS结合化学计量学用于安化黑茶的识别

采用顶空固相微萃取联合气相色谱—飞行时间质谱(GC—TOF MS)对安化黑茶及其它产地黑茶中的挥发性成分进行检测,对41种共有挥发性组分进行定性定量分析。应用化学计量学统计工具对数据进行变量筛选、主成分分析法(PCA)和偏最小二乘判别分析(PLS-DA),筛选出安化黑茶的26个显著性差异香气成分,通过主成分得分投影图直观反映样本间的聚类趋势和分类信息,对安化黑茶与不同产地黑茶样品及其它种类茶叶进行有效区分和识别,找出14个对安化黑茶识别分类起着重要作用的挥发成分。结果表明,基于茶叶中挥发性成分差异的GC—TOF MS分析结合化学计量学统计方法用于安化黑茶识别是可行的。

Discrimination of Anhua dark tea by gas chromatography-time of flight mass spectrometry combined with chemometrics

The volatile components in Anhua and other dark teas were analyzed by headspace solid phase microextraction (HS-SPME) combined with gas chromatography-time of flight mass spectrometry (GC-TOF MS). About 41 volatile compounds were analyzed qualitatively and quantitatively. A classification model and predict the authenticity obtained from variance analysis, principal component analysis (PCA) and partial least squares discriminate analysis (PLSDA). In addition, the 26 compounds significant impacting on the classification were screened out from Anhua dark tea. The straight forward classification trend of Anhua dark tea and other samples was visualized through projection score plots obtained by PCA. Effective classification and identification of Anhua dark tea, other origin dark tea and other kinds were carried out. The 14 important components for classification were found. The results showed that the developed GC-TOF MS method combined with chemometrics based on the volatile components in tea could be used to discriminate Anhua dark tea.