Abstract: DPPH-HPLC-QTOF-MS/MS was developed for rapid screening,identification and determination of antioxidants from Duzhong brick tea.After reaction with DPPH radical,HPLC peaks of nine antioxidants in Duzhong brick tea extract decreased or disappeared.By analysis of QTOF-MS/MS data,and by comparison with standards,their structures were identified as gallic acid,neochlorogenic acid,protocatechuic acid,chlorogenic acid,caffeic acid,(-)-epigallocatechin gallate,quercetin-3-O-sambubioside,rutin,and isoquercitrin.After that,a HPLC method was established for the simultaneous determination of nine antioxidants.The developed method had the potential to be a high throughput tool for rapid,sensitive,and accurate screening of bioactive compounds from complex matrices without tedious purification procedures,and the results could be used for quality evaluation and quality control of Duzhong brick tea.

Key words: DPPH-HPLC-QTOF-MS/MS, Duzhong brick tea, antioxidant, polyphenol compound