Putting the "De" in Decaf

Overview

Extraction and purification of caffeine is a common low-cost organic chemistry lab. Many protocols include recrystallization for purification and many use thin layer chromatography (TLC) to check the purity. The purpose of this project was to follow a method for extracting caffeine from caffeine pills and then see which recrystallization solvent would give us the purest caffeine. Horbäach Caffeine 100mg tablets were chosen because they contain stearic acid, which dissolves in organic solvents but not water, making them a good challenge for purification. Our extraction method involved dissolving the tablets in hot water, hot gravity filtration, liquid-liquid extraction with ethyl acetate, adding a drying agent, decanting, and evaporating the solvent. For the TLC mobile phase, an 80:20 ethyl acetate to ethanol mixture was used. The purity of caffeine in the tablets was ~50% initially and 100% following the extraction. Recrystallization with ethyl acetate, ethanol, and water was attempted, however we were unable to get enough crystal growth using ethanol or water, and the crystals grown using ethyl acetate were accidentally lost. We conclude that TLC is likely not precise enough to measure the purification of caffeine from tablets using recrystallization after extraction, because no impurities were found in our extract. Therefore, when designing an organic chemistry lab that measures the purification of caffeine extract, a melting point analysis or other more sensitive measures would need to be used.

Competition history

• CSEF 2026 Chemistry (Junior Division) · Entry J-05-13

Related projects

Closest projects by meaning, across every fair and year in the corpus.

Browse more like this

• All Chemistry projects
• CSEF Chemistry projects
• Every CSEF 2026 project