Abstract:

The contents of eight tea polyphenols and caffeine in wastes from various types of tea were determined by high
performance liquid chromatography using 0.6% formic acid-water (A)-acetonitrile (B) as the mobile phase at a flow rate of
0.8 mL/min with gradient elution from 0 to 60 min (5%–30% B). The column was Agilent SB-Aq C18 (4.6 mm × 250 mm,
5 μm). The HPLC column temperature was 30 ℃, and the detection wavelength was 278 nm. The results showed a good
linear relationship (r ＞ 0.99) for epigallocatechin gallate, gallocatechin gallate, epicatechin gallate, epecatechin, caffeine,
gallic acid, protocatechuic acid, gallocatechin and epigallocatechin in the concentration range of 10 ng to 20 μg. The RSDs
of repeatability and stability were both less than 15%. This method was simple, accurate and repeatable and allowed reliable
analysis of tea wastes.

Key words: high performance liquid chromatography (HPLC), tea, polyphenols