Identification of Raw and Ripe Pu-Er Tea by HPLC-MS/MS with Pattern Recognition

HPLC-MS/MS and HPLC were applied to the qualitative and quantitative analysis of raw and ripe Pu-Er tea. Eight main components were identified; they were gallic acid (GA), gallocatechin (GC), epigallocatechin (EGC), catechin (C), caffeine (CAF), epicatechin (EC), epigallocatechin gallate (EGCG) and epicatechin gallate (ECG). The contents were used as characteristic indexes for the identification of 20 batches each of the raw and ripe tea by pattern recognition techniques, including principal component analysis (PCA), clustering analysis (CA) and linear discriminant analysis (LDA). The proposed method was useful for distinguishing between raw and ripe Pu-Er tea.