Isocratic elution system for the determination of catechins, caffeine and gallic acid in green tea using HPLC

A simple high performance liquid chromatographic analysis for tea catechins, caffeine and gallic acid with an isocratic elution system was developed. The separation system consisted of a C18 reversed-phase column, an isocratic elution system of methanol/water/orthophosphoric acid, and an UV detector. This method is ideally suited for rapid, routine analysis for the determination of catechins in green tea with good repeatability and accuracy of results. Furthermore, this method can be applied to all kinds of tea and tea products, and is especially useful for the determination of (+)-catechin, which was regarded as being in too low a concentration to detect, and (-)-gallocatechin gallate, which was regarded as a measure for heat treatment for green tea. (C) 1999 Elsevier Science Ltd. All rights reserved.