For a successful TLC experiment, you need to pay attention to the details. From the list of instructions and tips below, select
the detail that is NOT important to a TLC experiment. O O Do not disturb the developing chamber. Do not move it or carry around. Closely monitor the temperature of the solvent in the chamber. Use only a plain pencil to draw a starting line and mark the compounds' spots. A pen or marker should never be used. Cover the developing chamber with a watch glass. Ensure the solvent level in the chamber is lower than the starting line where you spot the samples.
The concept of TLC is that a solvent (or mixture of solvents) ascends in a capilary system and the differences in interections between solvent and capilary of the substances present allow their separation.
In this process it's important that the air is saturated with solvent vapor, so the lid is important; the solvent must ascend by the capilar, so making it stedy is important, also making sure the starting line is above the solvent level is crucial for this same reason; using a marker would ruin a experiment because most marker's ink (if not all of them) would be carried by the solvent as well, but carbon is not, so a pencil must be used.
