The Selection Principle of Silica Gel Column
Commonly, the maximum sample loading volume of a silica gel column is about 1/20 of the volume of the column’s silica gel. However, as a practical matter, specific sample loading volume should be decided by each constituent’s degree of separation and solubility.
Wet Process Sample Loading
Generally, when the samples have good solubility, laboratory workers can perform wet process sample loading. Wet process sample loading has the characteristic of easy and less loss. One thing which has to be noticed is that the solvent for wet process sample loading must be a low polar eluting agent or with a low percentage of a polar solvent. Otherwise, the constituents will be easily eluted. What is more, the volume of the solvent should not be more than 10% of the flash column’s volume.
Dry Process Sample Loading
Laboratory workers normally use dry process sample loading to process most samples. The thing to notice is the choice of volume and specification of silica gel. The volume of silica gel is one to two times of the sample, and the specification is always with the mesh number of 200 to 300. But when the sample is hard to be mixed evenly and dryly, you should choose silica gel with the mesh number of 100 to 200.
