Selection of HPLC Column Sorbent
HPLC column sorbent can be either inorganic substrate or organic polymer matrix. The ceramic substrate is mainly silica gel and alumina. Ceramic properties of inorganic substrate rigid, in solvents not easy to expand. HPLC – grade organic polymers are based on crosslinked styrene – diethylbenzene or methacrylate. Organic polymer matrix has small rigidity and is easier to compress. The solvent or solute can easily permeate into the organic matrix, resulting in the expansion of the filler particles, resulting in less mass transfer and lower column effect.
Silica gel is the most common matrix of HPLC column sorbent. Besides having inorganic matrix has high strength, but also provides a surface, can through the mature silicon alkylation technology a wide range of bonding of the ligands, made into reverse, ion exchange, hydrophobic and hydrophilic or molecular exclusion chromatography. Silicone matrix fillers are widely used in solvents, from polarity to nonpolarity. Its weakness is in the water-soluble alkaline flow phase instability. Generally, the recommended routine analysis of the silicone matrix filler is 2-8.