Liquid chromatography of macromolecules under limiting conditions of desorption. 1. Principles of the method

The liquid chromatography of macromolecules under limiting conditions of de sorption (LC LCD) is based on a combination of exclusion and adsorption sep aration mechanisms. fluent promotes desorption of macromolecules that are d issolved in an adsorption-promoting liquid and injected into a liquid chrom atographic (LC) column packed with porous adsorptive packing. The zone of s ample solvent forms an "adsorption promoting barrier". Under properly chose n, "limiting", conditions the transport of adsorbing polymer species along the column is slowed since they cannot pass the above adsorption-promoting barrier. As result, macromolecules of various sizes and molar masses leave LC column in the form of a rather narrow band immediately behind the zone o f their initial solvent. At the same time other kinds of polymer chains whi ch exhibit lower affinity toward column packing and less adsorption surmoun t the zone of their original solvent. They are eluted in the size exclusion chromatographic mode. In this way macromolecules with different chemical s tructures can be discriminated. The LC LCD idea has been tested with a mode l system comprising poly(methyl methacrylate) probes, silica gel column pac king, toluene (adsorbing liquid), and tetrahydrofuran (desorbing liquid). S ome applications of this novel LC procedure have been proposed. They includ e separation of two-component and multicomponent blends, various kinds of c opolymers, and oligomers.