Rosheen Villaraza, Dana Young, Dana Yu*, and Ray Zafra
Department of Biological Studies, University of Santo Tomas, Manila, Philippines
Abstract
Experiment 3 highlights the separation of caffeine from tea leaves and using chromatography for testing its purity. Extraction is a method of separating the desired from the undesired substance in a mixture through the solubility properties of the substances. In the experimental extraction, Camellia sinensis was used and extracted with CH2Cl2, 6M NaOH, and NaS04 which yielded 0.0258g or 0.25% caffeine. Water boiling point is 100℃ while caffeine boiling point is 178℃. Extracted caffeine was tested to be pure through a comparison with a pure caffeine in the method …show more content…
Caffeine can be initially extracted from tea leaves by boiling it in water and isolated through liquid-liquid extraction with the usage of dichloromethane and other solvents (Rebecca, Candace Seshiah, & Tissopi, 2006). Water extraction and organic solvents extraction, that uses chemicals such as methylene chloride and dichloromethane, are the most common methods for further removal of caffeine from tea (Lou et al., 2012).
The objectives of this experiment are to isolate, purify, and characterize caffeine from tea leaves and to calculate the percent yield of extracted caffeine. The experiment focuses on the extraction of caffeine from the standard green tea of the brand name Lipton and disregards other types of teas such as black tea, oolong tea, and white tea.
Results and …show more content…
Residual water, due to the slight solubility of water and dichloromethane, will be present in the extract and can be dried by using an anhydrous sodium sulfite, which is an insoluble inorganic solid that will absorb water thus drying the extract (Postu & Wilson,