Stationary Phase In Column Chromatography

The stationary phase or adsorbent in column chromatography is a solid. The most common stationary phase for column chromatography is silica gel, the next most common being alumina. Cellulose powder has often been used in the past. Also possible are ion exchange chromatography,reversed-phase chromatography (RP),affinity chromatography or expanded bed adsorption (EBA). The stationary phasesare usually finely ground powders or gels and/or are microporous for an increased surface, though in EBA a fluidized bed is used.

There is an important ratio between the stationary phase weight and the dry weight of the analyte mixture that can be applied onto the column. For silica column chromatography, this ratio lies within 20:1 to 100:1, depending on how close to each other the analyte components are being eluted.

Column chromatography proceeds by a series of steps.