Thin layer chromatography (TLC) is a simple and relatively fast analytical tool that is used to measure the extent of a reaction or measure the relative polarity of a molecule. The size of a spot is a measure of the compound’s relative concentration, and the height of the spot is a measure of the polarity (the higher the spot, the less polar). Rf values are relative and approximate assuming a solvent system of 20% ethyl acetate/hexanes. Substances that are excessively volatile or small in size will not show on the TLC plate.
A TLC is measured by clicking on the TLC jar and dragging the small TLC plate to the solution of interest. The resulting TLC will be displayed in its own window on a reproduction of an actual TLC plate. The TLC is divided into two lanes. The right lane shows the spots of the actual solution in the flask, and the left lane shows the spots for the starting materials used in the reaction for comparison. After a reaction has been quenched and worked up, the starting material spots are no longer shown. For simplicity and clarity, only the starting materials and products are shown. Solvents, bench reagents, and bench reagent byproducts are omitted. The X button closes the TLC window, and the Save button saves the TLC plate to the lab book.
The TLC plate can also be viewed in the Live Data tab. The TLC plate is timestamped with the time on the laboratory clock when the TLC was taken. The Save button saves the TLC directly to the lab notebook, the Zoom button opens up the zoomed in view that shows up initially when a TLC is taken, and the Delete button removes the TLC plate from the Live Data tab.