gel permeation chromatography

Gel permeation chromatography is a technique which is related to size exclusion chromatography, where a solution is transported over a stationary gel which acts as carrier, in which the different components have different transport speeds.

Gel permeation chromatography is a size based (molecular length) separation technique.

Testing procedure

In Gel permeation chromatography the slowing down is generated by adsorption of dissolved material onto the stationary phase, where the smaller molecules stick longer than the larger ones.

If the molecules fit into the pores, they have a longer way to travel then those who won’t fit. So smaller molecules take longer than larger ones.

From the resulting data it is possible to retrieve the average molecular weight, the molecular mass distribution and the size of the molecules.

Testing applications

Determination of:

  • Molecular weight and distribution
  • Possible branching or co-polymerisation
  • Spread of possible degradation in recyclates