How to perform a TLC?
Experiments B: influence of the deposit diameter
On the same TLC, place PhCHO in dichloromethane / petroleum ether 1/1 by volume (solution 7):
- using a Pasteur pipette (deposit A)
- by emptying the capillary (deposit B)
- with a capillary, putting in the smallest possible drop (deposit C)
Dry the TLC plate thoroughly (in the air under the hood) and then elute in dichloromethane / petroleum ether 1/1 (C0 chamber).
Observe and conclude.
Perform the same experiment by depositing solution 11 (ferrocene in petroleum ether) and using petroleum ether as eluent (chamber C2).
Example of a solution of benzaldehyde PhCHO in dichloromethane.
Two or three deposits were made, with varying deposit volumes (one drop, two drops or 5 drops)
Two or three deposits were made, with varying deposit volumes (one drop, two drops or 5 drops)
We observe that:
- the spots are wider when using a pipette instead of a capillary
- concentrating the deposits or increasing the volume of deposit also increases the width of the spots, but also makes it possible to see impurities in the initial compound, benzaldehyde
Click on each box to see the result