HPLC Columns

Normal Phase

Adsorption chromatography is usually achieved with non-derivatized silica packing materials. Retention of the analytes is primarily caused by the interaction of polar groups with the silanol on the silica surface.
Adsorption chromatography is used for analytes with medium polarity that is soluble in organic solvents. It is not suitable for polar analytes, because these analytes will interact with the silica surface, resulting in poorly shaped peaks or even no elution at all. Variations in separation with silica gels from different manufacturers are caused by differences in shape and pore size, particle size, surface area or types of silanol groups.