"Silica gel blue" is silica has a moisture indicator, usually a cobalt compound, to indicate it is unable to adsorb moisture, making it unsuitable for column chromatography. This silica may not be the most "pure", so it may contain impurities that can affect the chromatography especially for basic compounds, also the moisture indicator will affect the chromatography as well. If developing a method from TLC plates, that moisture indicator could affect the retention compared to the TLC plate.
What is the source of the powdered silica gel? Some are made for chromatography, and some powdered silica gel is made for other applications and won't work for chromatography. for example, some powdered silica has a small particle size that impedes the flow for column chromatography.
Specific grade for column chromatography is available (80-120 mesh). It is advisable to use that only for the best results.
Dry or powdered Silica of a specific mesh (Usually 80-120) is used for column chromatography to get a very good result. If you are interested in purification of biologically active compounds for subsequent spectroscopic analysis like NMR, then it is advisable to use dry silica for the purification.
- Badges
- Science method