I have a question on thin layer chromatography (TLC).
My mobile phase (i.e. developing solvent) is a mixture of 2 non-polar solvents.
After preparing the mobile phase, is it necessary to pour some into the developing chamber to saturate the chamber or should we only pour the mobile phase into the chamber just before we place the TLC plate in?
I tend to put the mixture in the developing chamber a while before I run the TLCs. Not too important if all you are doing is looking for the disappearance of starting materials/appearance of product.
Getting the chamber saturated can be important with prep-TLCs where you want an even separation across a wide solvent front.
When performing thin layer chromatography (TLC), it is important to properly saturate the developing chamber with the mobile phase before placing the TLC plate in it. This step ensures that the atmosphere inside the chamber is saturated with the solvent vapors, which in turn helps the compounds to move evenly and consistently up the TLC plate when it is dipped into the chamber.
To properly saturate the chamber, you can follow these steps:
1. Choose a suitable developing chamber such as a beaker, glass jar, or TLC tank.
2. Prepare your mobile phase by mixing the non-polar solvents according to your specific experimental requirements.
3. Pour an adequate amount of the mobile phase into the chamber, ensuring the level is sufficient to cover the bottom by a few millimeters.
4. Place the lid or cover on the chamber and allow it to sit for some time, typically around 10-15 minutes. This will allow the atmosphere inside the chamber to become saturated with the solvent vapors.
5. After the chamber has been properly saturated, carefully place the TLC plate into the chamber, ensuring that the solvent level is below the baseline marked on the plate.
6. Replace the lid or cover on the chamber to maintain the saturated atmosphere and allow the chromatography to proceed.
By following these steps, you ensure that the TLC plate is exposed to an environment in which the solvent vapor pressure is consistent, leading to better separation and accurate results during the analysis.