Isolating Caffeine from Tea
Oct. 23, 2012
The purpose of this lab was to determine the concentration of caffeine from tea leaves through a simple extraction and sublimation process. With added ingredients including dichloromethane (DCM) and sodium carbonate to help separate and extract caffeine, the mass of the caffeine isolated was determined and compared to other products containing the same ingredient.
Caffeine is found in many dietary products consumed everyday, coffee and tea being the most commonly known. Recent studies suggest that consumption of coffee in appropriate amounts may reduce the risk of certain diseases, however, there are many side effects associated with increased caffeine intake. Not only can the body undergo withdrawal because of its addictive tendencies, it can also lead to anxiety, insomnia, gastrotestinal disturbances and increased blood pressure (Nature, pg. 956). The idea of creating and cloning the caffeine synthase gene in order to produce newer generation of plants that are caffeine-deficient is becoming more popular. To create the same benefits, without the harmful effects of caffeine is an expensive process and may result in loss of flavor and aroma within the product (Nature, pg. 956). To isolate caffeine from various substances requires different methods based on the composition of the solution it is being extracted from. High pressure processing is a new method that extracts caffeine from tea leaves and has been shown to have an advantage such as shorter extraction times (Nature.com). Similarly, the process of extracting and sublimating this ingredient from tea leaves was performed in the following experiment and its concentration was determined.
When the prepared tea solution has cooled down to room temperature, transfer 10-mL of tea into two centrifuge tubes. Add 3-mL of methylene chloride and 0.5g of sodium bicarbonate to each centrifuge tube. Shake...