[wildfyr]

Rolnor, the post you quoted was from Sept 2015, and I haven't seen that name in a while. I doubt he will respond.

In terms of studying this, it seems to me that dynamic light scattering would be the way to look at this. You take silica gel, suspend it in some solvent or solvent mixture, filter it through a frit that should stop the gel, and put it on DLS. If the silica is truly dissolved there won't be particles, if its just suspended, there will be a DLS profile of particle sizes.

[rolnor]

Thanks, i missed the date. It could be that very small particles breaks loose from the gel when polar protic solvents are used. I really think someone should look in to this, many of my collegues have observed this when working with nucleosides. DLS sounds like a good start.

[lb2]

Here is a brief "study" supporting the idea that granular silica gel can shed some fines:

http://www.flash-purification.com/does-methanol-really-dissolve-silica-during-flash-column-chromatography/

[pgk]

Although SiO2 is considered to be water insoluble, it forms colloids and hydrogels with water that deteriorate the separation. Methanol further boosts that hydrogel formation. Besides, there is more than 5% water in the typical eluent because super-dry methanol and/or glacial acetic are unlike to be used. As a conclusion, water must be avoided in normal chromatography.

[rolnor]

According to the link above the problem seems to be not so big but to avoid it spherical silica is better.

[mikarus]

I think that I had this problem of dissolving silica in MeOH, or even more correctly reacting it with my compound.
I used silica gel column chromatography to purify a partial ester of bisphosphonic acid and used gradient elution with DCM/MeOH mixtures. I ended up with rather low yield of my product even though my crude was composed mainly of the desired product. Moreover, according to NMR 1H the “silica complex” of my bisphosphonic acid partial ester had the right integration of hydrogens as “normal” non-silica containing product, but the peaks were all broadened. And this silica containing product was elited with a lot of MeOH