Isolation, Characterization and Purity Assessment of Caffeine from Commercial Tea Products

Caffeine is found in coffee, tea, cola, and guarana and serves as a CNS stimulant. Solvents such as dichloromethane and ethyl acetate were used to extract caffeine from green and black tea leaves obtained from local market. The product obtained with the Solvent Ethyl acetate was 0.72 percent for green tea and 0.82 percent for black tea. Caffeine obtained from Dichloromethane was 0.85 percent for green tea and 1 percent for black tea. The melting points of these caffeine samples were determined and are comparable with Pure caffeine. and Caffeine was identified using phytochemical testing and Thin layer Chromatography. The Rf of Caffeine extracted from Green and Black tea with Dichloromethane was found to be 0.7cm and 0.68cm, respectively, and from Ethyl acetate was found to be 0.67cm and 0.66cm. Caffeine samples were characterized by Fourier Transform Infrared Spectroscopy (FTIR) by the presence of the functional groups C-NH2, Sp3-C, and C=O. Caffeine was quantified by UV visible spectroscopy and the % Purity ranges from 98.12% to 99.11% among various samples.