extraction fractionation

of polymers
https://doi.org/10.1351/goldbook.E02306
A process in which a @M03667@ material, consisting of macromolecules differing in some characteristic affecting their @S05740@, is separated from a @P04745@ into fractions by successively increasing the solution @P04792@ of the solvent, resulting in the repeated formation of a two-phase system in which the more soluble components concentrate in the @P04744@.
Source:
Purple Book, 1st ed., p. 68 [Terms]