蒙顶黄芽水溶性成分LC-TOF/MS指纹图谱及定量分析

用液相色谱-飞行时间质谱联用仪（LC-TOF/MS）研究四川蒙顶黄芽指纹图谱，并对蒙顶黄芽的主要水溶性成分进行定量分析，为四川蒙顶黄芽的成分分析与鉴别提供理论依据。以24个蒙顶黄芽样品为实验材料，采用梯度洗脱（A相为0.1%甲酸溶液，B相为乙腈），柱温30℃，检测波长278 nm，流速0.2 mL/min，建立蒙顶黄芽LC-TOF/MS指纹图谱，确定共有色谱峰，并进行了定量分析。24个蒙顶黄芽样品具有16个共有色谱峰，确定了9种化合物，分别为GC（没食子儿茶素）、EGC（表没食子儿茶素）、CAF（咖啡碱）、C（儿茶素）、EC（表儿茶素）、EGCG（表没食子儿茶素没食子酸酯）、GCG（没食子儿茶素没食子酸酯）、ECG（表儿茶素没食子酸酯）与CG（儿茶素没食子酸酯）；定量分析表明，不经过闷黄工艺制成的蒙顶黄芽GC、EGC含量较低，EGCG、ECG含量较高；而用陈茶炒黄的蒙顶黄芽EGCG含量均较低；因子分析表明，14个品质成分综合为4个公因子，前4个公因子的特征值大于1且累计贡献率达80.44%，主要代表性指标为儿茶素类、咖啡碱、蛋白质和糖类等；当临界值小于20时，通过聚类分析将24个样品分为4类。根据构建的蒙顶黄芽LC-TOF/MS指纹图谱，可以鉴定和评价不同工艺的四川蒙顶黄芽。

LC-TOF/MS Fingerprint and Quantitative Analysis of Water-soluble Components in Mengding Yellow Bud

Sichuan Mengding yellow bud have been fingerprinted by using the liquid chromatography-time-of-flight mass spectrometry(LC-TOF/MS)and quantitatively determined its major water-soluble constituents for the purpose of providing theoretical evidence for the identification of Sichuan Mengding yellow bud.Used 24 samples of Mengding yellow buds as experimental materials,gradient elution(phase A was 0.1%formic acid solution and phase B was acetonitrile)was used.Column temperature was 30℃,detection wavelength was 278 nm,flow rate was 0.2 mL/min.The LC-TOF/MS fingerprint of Mengding yellow bud was established and cluster analysis was performed to determine the common chromatographic peaks.24 samples of Mengding yellow buds had 16 common chromatographic peaks,and 9 compounds were identified,namely GC(gallocatechin),EGC(epigallocatechin),CAF(caffeine),C(catechin),EC(epicatechin),EGCG(epigallocatechin gallate),GCG(gallocatechin gallate),ECG(epicatechin gallate)and CG(catechin gallate).Quantitative analysis showed the content of GC and EGC in the yellow buds of Mengding yellow bud without piling fermenting process was low,and the content of EGCG and ECG was high,while the content of EGCG in Mengding yellow bud fried with stale tea was low.Factor analysis showed that 14 quality components were combined into 4 common factors.The characteristic values of the first four common factors were greater than 1 and the cumulative contribution rate was 80.44%.The main representative indicators were catechins,caffeine,proteins and sugars.In addition,when the critical value was less than 20,the cluster analysis divided 24 samples into 4 categories.According to the constructed LC-TOF/MS fingerprint of Mengding yellow bud,the Mengding yellow bud from different processes can be identified and evaluated.