Chromatography of tea constituents.

Modern chromatographic techniques such as high-performance liquid chromatography are currently the most helpful approach to the routine analysis of and research of non-volatile tea constituents. Using these techniques some errors in the more classical analytical techniques could be detected. Unfortunately, some of these methods of analysis are still in widespread use, even as official methods. However, knowledge of especially the polyphenols in tea is still lacking, and for many of the minor polyphenols no chromatographic methods for the determination exist.