关键词: 黑茶, 高效液相色谱法, 咖啡因, 测定

Abstract:

A simple and accurate HPLC method for the determination of caffeine in dark green tea was developed. The chromatographic separation was achieved on a Kromasil C18 column (column temperature 25 ℃) using a water-methanol-acetic acid-dimethylformamide (70:30:0.05:0.25, V/V) mobile phase with a sample injection volume of 5 μl prior to UV detection at 274 nm. The regression equation of standard curve for caffeine determination was Y = 6× 10-8X＋0.0044, where Y is caffeine concentration (mg/kg) and X is peak area (μV·s), R2 = 0.9997. The analytical method exhibited a variation coefficient of 3.96%, and the spike recovery rate of caffeine was between 90.62% and 103.8%.

Key words: dark green tea, HPLC, caffeine, determination