L-Theanine in Green Tea

L-Theanine is a naturally occurring amino acid analog that is found in green tea. It is a psychoactive compound and there is a growing need to its pharmacological effects. The compound does not have significant UV absorption which makes adequate sensitivity in UV-based analyses problematic. Furthermore, the compound is polar and not suited to conventional reversed phase HPLC analyses. In this application note, the Diamond Hydride 2.0™ column is used to study of L-theanine in green tea. The column is designed for use in aqueous normal phase and the particle diameter is much lower than standard 4 or 5 μm phases, this increases efficiency of analyte peaks.