Thin Layer Chromatography Discussion Part 1

In the experiment of TLC, unknown 3 moved 2.1 cm. After conducting the experiment, the retention factors were calculated using Rf=y/x, ‘y’ was the distance the spot traveled and ‘x’ was the distance the solvent traveled. The average for each compound’s Rf was calculated. Aspirin’s Rf was 0.2115, Acetaminophen Rf was 0.358, caffeine's Rf was 0.089, unknown 1 Rf were 0.426, 0.089, and 0.375 and unknown 3 Rf was 0.360. Based on the Rfs and spotting, unknown 1 contains acetaminophen and caffeine. Unknown 3 contains acetaminophen but no caffeine. As a result, unknown 1 is not pure because it contains multiple compounds although unknown 3 is pure. Potential errors could be caused by human error if the solvent did not rise high enough.