•Size Exclusion Chrom. (SEC)
•Packings are porous polymeric           (resins) or silica based materials
•Two names used for the same process:
•1) Gel filtration chrom. = aqueous solvent
2)Gel permeation chromatography = non-aqueous mobile phase
•Column packing works like a molecular filter allowing small molecules access to every pore, retarding their progress – large molecules pass thru more quickly