size-exclusion chromatography (SEC)

https://doi.org/10.1351/goldbook.S05705
A separation technique in which separation mainly according to the hydrodynamic volume of the molecules or particles takes place in a porous non-adsorbing material with pores of approximately the same size as the effective dimensions in solution of the molecules to be separated.
Source:
Purple Book, 1st ed., p. 69 (http://old.iupac.org/publications/books/author/metanomski.html)