Evaluation of liquid chromatography column retentivity using macromolecular probes: IV. Poly(ethylene glycol) bonded phase

Interaction properties of the novel HPLC silica gel–poly(ethylene glycol) (PEG) bonded phase were evaluated applying polymeric test substances, viz. polystyrenes, poly(methyl methacrylate)s, poly(ethylene oxide)s and poly(2-vinyl pyridine)s, and eluents of different polarities. Silanols on the silica gel surface are well shielded by the PEG phase, and silanophilic adsorption of macromolecules is suppressed in comparison with most silica C18 bonded phases. The adsorption of solutes on the OH groups of the PEG phase seems to be low as well. The partition of macromolecules in favor of the PEG phase is inferior to that observed in case of the silica C18 phases. The volume of the PEG bonded phase is small and it is supposed that the PEG chains assume flat conformation on the silica gel surface.