Gel Permeation Chromatography : GPC

Principle

Gel Permeation Chromatography (GPC) is one of liquid chromatography in which separation is based on differences in molecular size. Distribution of molecular weight and average molecular weight are measured by GPC. Polymer molecules are separated in the gel packed column whose pore size is as same as the molecular size in dilute solution (hydrodynamic volume). High-molecular-weight components are eluted faster than low-molecular-weight components, because larger molecules are less permeable into the pore of the gel than smaller molecules. Therefore GPC is also described as size exclusion chromatography (SEC).
When a light scattering detector is used in combination with this system, it is possible to obtain information on the absolute molecular weight distribution, absolute average molecular weight, and radius of gyration of polymer.