Abstract: A HPLC method was established to determine five kinds of water-soluble vitamins content in different tea. Optimization of tea pretreatment and chromatographic conditions were obtained. Experiments showed that treatment of tea samples solution pretreated with saturated lead acetate solution. The chromatographic separation was achieved by using a C₁₈ column with dimension of 4.6 mm×150.0 mm and particle size of 5 μm. A mixture of methanol and NaAC-HAC buffer solution（pH=5.5）was used as mobile phase. The effluent was monitored at 266 nm, with flow rate of 1 mL/min and gradient elution. The results showed that the separation of VB₁, VB₂, VB₆, Vc and nicotinic acid was the best in the condition of in HPLC samples, the content of vitamin C, vitamin B1 and vitamin B2 in black tea was more, were 3.69、2.92 and 5.18 μg/g. The content of vitamin B₆ in green tea was more, was 2.30 μg/g. Green tea and Oolong were not detected in vitamin B1. And four kinds of tea were not detected niacin. The method can detect the content of water-soluble vitamins in four kinds of tea, and provide the reference for the quality control of tea.

Key words: tea, water-soluble vitamin, HPLC