In: Chemistry
describe the process whereby iodine visualizes otherwise invisible components of a developed thin layer plate
The method for the visualization of organic compounds with iodine vapor is based on the observation that iodine has a high affinity for both unsaturated and Aromatic compounds.
The process whereby iodine visualizes otherwise invisible components of a developed thin layer plate has following points:
In this method a chamber of around 100 mL wide mouth jar (with
cap) is added a piece of filter paper and few crystals of iodine.
Iodine has a high vapor pressure for a solid and the chamber will rapidly become saturated with iodine vapor.
Now insert the TLC plate and allow it to remain within the chamber until it develops a light brown color over the entire plate.
If the compound has an affinity for iodine, it will appear as a dark brown spot on a lighter brown background.
Now remove the TLC plate Carefully and gently circle the spots with a dull pencil, because after some time iodine will not remain on the TLC plate .