Related Experiment Video
Updated: Oct 4, 2026

On-chip Isotachophoresis for Separation of Ions and Purification of Nucleic Acids
Published on: March 2, 2012
Dependence of reversed-phase retention of ionizable analytes on pH, concentration of organic solvent and silanol
1Waters Corporation, Milford, MA 01757, USA. uwe_neue@waters.com
Abstract:
In reversed-phase chromatography, the retention of ionizable analytes is influenced by the ionic properties of the packing caused by surface silanol groups. We have measured the ion-exchange properties of both reversed-phase bonded phases and their underlying base materials. The probe used in this part of the study was bretylium tosylate. The acquired knowledge is then used for a complete and quantitative understanding of the retention behavior of ionizable compounds as a function of the pH of the mobile phase and the solvent composition. We have studied the retention pattern of a broad range of acids, bases, and polyfunctional analytes over the pH range from 2 to 11 and from water to 80% acetonitrile. A few application examples demonstrate the relevant findings.
More Related Videos
Related Concept Videos
High-Performance Liquid Chromatography: Introduction
In HPLC, two phases play a critical role in the separation process:
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...
Analyte Adsorption and Distribution
Ion-Exchange Chromatography
Titration in Nonaqueous Solvents
Solvating Effects

