GPC – Gel Permeation Chromatography
The gel permeation chromatography is a method in which dissolved molecules are separated according to their hydrodynamic volume. The separation is done by the diffusion volumes of a stationary phase or the different diffusion intensities of containing molecules into the pores of the packing material. Small molecules diffuse more strongly, are retained longer on the column and elute later. Large molecules pass through the chromatography more quickly and are present in earlier fractions of the eluate.
To draw conclusions about the properties of individual fractions, retention times are compared with those of known standard molecules. For the characterization of the eluted sample various detectors are used (e.g. refractive index, light scattering or viscosity detectors). They allow a calculation of the distribution of absolute molecular weight, molecular size or intrinsic viscosity.
The method is used for the analysis of macromolecules such as polymers, biopolymers or proteins.