How to perform a TLC?
Experiment C: influence of duration
Place benzaldehyde on a piece of TLC plate (solution 7).
Observe:
- immediately under UV
- after 20 minutes
- after 1 hour
Elution of benzaldehyde (PhCHO) in dichloromethane:
a) Just after the end of the elution
b) After removing the TLC from the chamber, and after 20 minutes left in the air
c) After removing the TLC from the chamber and after 2 hours left in the air
b) After removing the TLC from the chamber, and after 20 minutes left in the air
c) After removing the TLC from the chamber and after 2 hours left in the air
Just after the end of elution, there is benzaldehyde (and an additional spot due to the presence of an oxidation product: benzoic acid PhCO2H)
After removing the TLC from the chamber, and after 20 minutes left in the air: the intensity of the spot is attenuated.
After removing the TLC from the chamber and after 2 hours left in the air: the spots of the two products, which are volatile, have almost completely disappeared.
Click on each box to see the result