Gel permeation chromatography on unmodified silica using aqueous solvents

Liquid chromatographic elution characteristics of some solutes used to measure column void volume on C18 bonded phases

“…Explanation of these results is facilitated by conclusions drawn from gel permeation (or size exclusion) chromatography (GPC). Experiments on the electrolyte effects of salts in aqueous GPC (22,23) have established that when an unbuffered solution contains two or more different ionic species, a Donnan salt-exclusion effect occurs, and one of the solutes is blocked from regions penetrable by the others. The presence of a salt in the eluent is used to prevent interference from the Donnan equilibrium.…”

Interference Prevention in Size-Exclusion Chromatographic Analysis of Debranched Starch Glucans by Aqueous System

“…Molecules move differently in a size-exclusion column due to the hydrodynamic volume rather than the molecular weight. − Our study further indicated that ionic interaction significantly altered linear velocity of an ionized molecule in a polymeric size-exclusion column. In some cases, a weak anionic water-soluble polymer, dextran ( M w = 2 kg/mol), could be excluded from the pores of silica gel upon elution with water, but a mixture of pullulans was eluted without a good correlation with molecular size when a silica gel packed column was eluted with water (data not show). In other studies, the addition of ammonium sulfate to the eluent was thought to provide ionic strength and avoid interference peaks from sulfate; however, it has also been mentioned that sulfate ions can enhance the retrogradation of amylose solutions, − and, therefore, we excluded it from this investigation.…”

Preparation and evaluation of a bimodal size-exclusion chromatography column containing a mixture of two silicas of different pore diameter

“…SEC has been applied to a variety of separation problems, particularly those involving macromolecules. Polymers with a narrow molecular weight distribution can be separated into narrow bands (3), while the characteristic molecular weight distribution curve of broad molecular weight polymers can also be obtained (4). SEC of biopolymers has been of particular interest with the development of many procedures for the molecular weight separation of peptides and proteins (5).…”