CHM 2123 Lecture Notes - Lecture 1: Claire King, Elution, Filter Paper

• School: University of Ottawa
• Department: Chemistry
• Course: CHM 2123
• Professor: Katherine Mc Gilvray

Document Summary

Extraction was used to extract caffeine from black tea and sublimation was used to further purify that caffeine product. Tlc was used to verify the purity of the crude and purified caffeine products by comparing them to a pure caffeine sample. Extraction separates products from a mixture by utilizing the differences in solubility"s of two immiscible solvents. Sublimation is the transfer of a substance from the solid to the gas phase without the intermediate liquid phase. Caffeine (1,3,7-trimethylxanthine) is a xanthine; xanthines are a group of alkaloids known for their stimulating properties. Caffeine occurs naturally in the leaves of the plant. Camellia sinensis that are brewed to make black tea. The health benefits of black tea come from the polyphenols that are extracted from the tea leaves along with the caffeine when brewing tea. Catechins, theaflavin, and theanine are all polyphenols found in black tea. This lab outlines the isolation of caffeine from these polyphenols.