GPC/SEC/GFC - Size Separation
Determination of Molar Mass Distribution and Averages

• GPC (Gel Permeation Chromatography),
• GFC (Gel Filtration Chromatography) and
• SEC (Size Exclusion Chromatography)

are names used to describe the same liquid column chromatographic technique required to determine important properties of macromolecules, also known as polymers, biopolymers, polysaccharides or proteins. Independent of the abbreviation used, the separation mechanism behind these names is the same. SEC is the name that describes the chromatographic process best, as molecules are sorted by their size.

The size separation step occurs in a column filled with porous particles (stationary phase) and is an entropic driven process. First, the sample is dissolved in a solvent, which is also used as a mobile phase. The sample solution is injected onto the column. Here larger sizes are excluded from penetrating the pores in the stationary phase particles while smaller sizes can enter them and thus are retarded on their way through the column.