Lab: Chemistry
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At the end of this lab, students should know...
Thin-layer chromatography (TLC) is a technique used to separate organic compounds based on differences in their polarities.
The three components of the TLC system are the stationary phase, the mobile phase or solvent, and the solute.
Less-polar solutes generally remain in the less-polar organic solvent, while more-polar solutes will preferentially interact with the highly polar stationary phase.
The TLC plate is generally prepared with a fluorescent compound mixed into the stationary phase. Since most organic compounds are colorless, they appear as dark spots on the glowing plate when exposed to UV light.
The retardation factor (Rf) is the ratio of the distance traveled by the solute to the distance traveled by the mobile phase solvent. This is solvent specific and is a physical characteristic of a compound.
Source: Lara Al Hariri at the University of Massachusetts Amherst, MA, USA
Here, we show the laboratory preparation for 10 students working in pairs, with some excess. Please adjust quantities as needed.
3 50-mL glass screw-top jars |
3 10-mL graduated cylinders |
1 Pencil |
1 Labeling pen |
1 Pair of tweezers |
1 Small ruler with metric increments |