ABSTRACT
Molecules percolate through and around the porous beads in the column and are separated according to their mass and shape. The technique is named ‘size exclusion’ chromatography because the pores within the material (Figure 5.1) have a maximum pore size, so that a component which is larger than the pore size will be excluded from entering into the porous material and will travel down the column in the liquid volume surrounding the porous beads. Small molecules will also be able to travel down the column in the liquid volume surrounding the porous beads but they will also be able to diffuse into the volume within the beads. These smaller molecules can diffuse (partition) into a larger volume. The net result is that molecules applied to SEC will elute from the column in decreasing molecular mass.
