Determination of Caffeine in Tea by High-Performance Liquid Chromatography

Abstract

A simple and rapid method for the assay of caffeine in tea was developed by employing highperformance liquid chromatograph with UV detector. An assay solution was prepared as follows: 100mg of pluverized tea was extracted for 30min with hot water (80°C). The extract was filled up to 100ml and added 200mg of polyvinylpolypyrrolidone (PVPP) to remove the phenolics. A column (4.4×250mm) was pcked with ODS-SIL (reverse phase C18, particle size: 10μm) and eluted with MeOH-Water-AcOH (74:25:1) at a flow rate of 1.0ml/min. The caffeine content was detected at 272nm (AUFS: 0.08). From the peak height of UV monitor, a streight caliblation line was obtained in the range of the caffeine of 0.05-0.25μg. The correlation coefficient between the values obtained by the official method of Japan and those by HPLC method was 0.994.