Related Experiment Video
Updated: Oct 17, 2026

Ion Exchange Chromatography (IEX) Coupled to Multi-angle Light Scattering (MALS) for Protein Separation and Characterization
Published on: April 5, 2019
Re-evaluation of anion-exchange HPLC for the analysis of acidic compounds
1Zeneca Pharmaceuticals, Lead Discovery Department, Macclesfield, Cheshire, UK. brian.law@astrazeneca.com
Abstract:
A number of weak and strong anion-exchange HPLC phases have been evaluated for the analysis of acidic drugs and related compounds. Using eluents with high organic content, reasonable chromatography could be obtained and widely differing compounds easily separated in isocratic mode. Retention was related to solute pKa and concentration of ammonium acetate in the eluent. All the phases showed an unexplained loss in retention with repeated use, although with one material; nucleosil SAX, this was low (15%) and considered acceptable. This material was also shown to be relatively stable under typical bioanalytical conditions.
Related Concept Videos
Ion-Exchange Chromatography
Ion Exchange
Basicity of Heterocyclic Aromatic Amines
Titration of Polyprotic Base with a Strong Acid
High-Performance Liquid Chromatography: Elution Process
Titration of a Weak Base with a Strong Acid
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...

