Study on the HPLC-DAD-ELSD fingerprinting of dark teas from different regions in China

The chromatographic fingerprinting of dark teas from different regions in China was established by high performance liquid chromatography using diode array and evaporative light- scattering detector. The results showed that 27 common peaks were demarcated and eight constituents, for example, gallic acid and epigallocatechin were identified in the chromatographic fingerprinting with HPLC-DAD of 36 dark tea samples; 15common peaks were demarcated and six constituents, for example, glutamicacid and L-theanine were identified in the chromatographic fingerprinting with HPLC- ELSD.The results of similarity evaluation showed that the HPLCDAD similarity of 36 dark tea samples was from 0.903 to 0.979, the HPLC- ELSD similarity of 36 dark tea samples was from 0.902 to 0.974, and the similarity of six control samples was less than 0.900. The research supplies a reference method to the identification and quality assessment of dark tea.