ABSTRACT
The particle size of the packing material is given in some cases. It is important because the smaller and more uniform in size the packing material, the better the separation. Separation of compounds on silica gel columns is based on polar interactions between the components to be separated and the column packing material; consequently, increasing the polarity of the solvent reduces the retention times, and the more polar a substance, the longer its retention time. Microparticulate silica with amines bonded to the silica or, more recently, with the use of small quantities of amines in the mobile phase are useful methods for separation of purified, neutral mono, and lower oligosaccharides. Microparticulate silica columns are modified with relatively nonpolar side chains to produce reverse phase (RP) columns. The usefulness of ion-exchange resins for the separation of carbohydrates has been known for about 40 years. A paper recently described the use of a true anion-exchange mechanism for the separation of carbohydrates.
