[Babcock_Hall]

https://selekt.biotage.com/blog/how-do-i-purify-ionizable-organic-amine-compounds-using-flash-column-chromatography
http://www.chem.rochester.edu/notvoodoo/pages/chromatography.php?page=solid_phase
http://www.chem.rochester.edu/notvoodoo/documents/C18-RP-FC-Procedure.pdf

I am interested in purifying amines.  Somehow the idea using amine-functionalized silica (first link) did not get onto my radar until just now.  Does anyone have any positive or negative experience to share working with this kind of chromatography?  I am guessing that the medium is not cheap, but if it works, then it is worth it.  Another alternative is using triethylamine to pretreat the silica without having the TEA present in the mobile phase during the development of the column (see second link).  Another alternative is reverse phase chromatography (references and a pictorial walk-through at the third link).

[rolnor]

The easiest and cheapest way is to pretreat the silica with base. You can also use aluminium oxide wich is basic. RP-gel very expensive as is the amine-functionalized silica. Maybe ut depends in the scale of the work, small amounts material could be worth it?

Here is some price-comparison. RP-gel is 250usd/50g…

http://www.chem.rochester.edu/notvoodoo/documents/C18-RP-FC-Procedure.pdf

[Babcock_Hall]

If we pretreat with TEA, should TEA also be in the mobile phase?

[rolnor]

I think you can do in different ways, it will probably affect the RF. I usualy pack the column without TEA, then dissolve the sample in mobile-phase containing TEA and elute with mobile-phase containing TEA. This way the column will behave similar to a TLC-plate
that is developed in mobile-phase containing TEA. If you dont have TEA when you dissolve and load the sample on the column, it sometimes stick irreversible to the gel.

[wildfyr]

You could home-kit it. React silica gel with AMPTES ((3-Aminopropyl)triethoxysilane). Godspeed.