Silica Gel: One Of The Inorganic Substrate Of Flash Columns
The basic material of the stationary phase of the flash columns we called substrate is usually divided into three categories: inorganic materials, organic materials, and composite materials.
Silica gel is the widest materials used to make a matrix in flash columns. Silica gel used in the flash columns usually has a porous structure, which has high mechanical strength and thermal stability. Its surface contains a large number of active hydroxyl groups because of the excellent pore structure and specific surface area. It plays an important role in the purification and separation of compounds in normal phase purification system.
At the same time, the surface of silica gel can be easily modified to form other bonded stationary phases. And there are many kinds of stationary phases modified by silica gel substrate, and the effect of the separation and purification is much better than other kind of substrates.
However, the stability of silica gel substrates is relatively poor under alkaline conditions. Not only that, the presence of hydroxyl groups will cause irreversible adsorption of some substances, especially alkaline substances.
The non-specific adsorption or denaturalization of the sample appears in the separation and purification of some biological molecular samples, resulting in the difference of peak deformation of sample elution in the chromatogram and the decrease of sample recovery.