Rapid determination of caffeine in tea leaves

For the purpose of efficient screening of low-caffeine tea shoots, a method for the rapid determination of caffeine was developed using high-performance liquid chromatography. Polyvinylpolypyrrolidone was packed in a pre-column and used to remove polyphenols from tea extracts on-line. The concentrations of caffeine extracted from powdered tea leaves at 50°C during 1 day could be analyzed in 2–5 min intervals. The pre-column and the analytical column could be used for the analysis of more than 2000 samples.