SPE is an increasingly useful sample preparation technique. It eliminates many of the problems associated with LLE such as incomplete phase separation, poor recovery and large consumption of organic solvents. Moreover, SPE is much easier to perform in shorter run times and is more compatible with automation than LLE (Zwir-Ferenc & Biziuk, 2006). To the best of our knowledge, SPE using commercially available cartridges has not been reported for the analysis of GT tablets or on-column removal of caffeine from GT extract.