Related Experiment Video
Updated: Jun 30, 2026

Ion Exchange Chromatography (IEX) Coupled to Multi-angle Light Scattering (MALS) for Protein Separation and Characterization
Published on: April 5, 2019
Anion-exchange behavior of several alkylsilica reversed-phase columns
1Department of Chemistry, University of Wisconsin-River Falls, River Falls, WI 54022, USA. daniel.marchand@uwrf.edu
Abstract:
Some alkylsilica columns carry a positive charge at low pH, as determined by anion-exchange with nitrate ion. In the present study, the relative positive charge for 14 alkylsilica columns was measured for a mobile-phase pH 3.0. All but 3 of these columns were found to carry a significant positive charge under these conditions. The relative positive charge on these columns was found to correlate approximately with two other column characteristics: relative cation-exchange behavior as measured by the hydrophobic-subtraction model (values of C-2.8), and slow equilibration of the column to changes in the mobile-phase-as evidenced by a slow change in the retention of anionic and cationic solutes with time. The origin of this positive charge may arise from the bonding process, with incorporation of some cationic entity into the stationary phase.
Related Concept Videos
Silica Gel Column Chromatography: Overview
Polar components tend to bind strongly to the silica gel, causing them to move slowly through the column. In contrast, nonpolar compounds...
Ion Exchange
High-Performance Liquid Chromatography: Introduction
In HPLC, two phases play a critical role in the separation process:
Ion-Exchange Chromatography
Gas Chromatography: Types of Columns and Stationary Phases
For an analyte to remain on the column for a sufficient amount of time, it must exhibit some level of compatibility (or...
Analyte Adsorption and Distribution
