Related Experiment Video
Updated: May 8, 2026
10:41
Ion Exchange Chromatography (IEX) Coupled to Multi-angle Light Scattering (MALS) for Protein Separation and Characterization
Published on: April 5, 2019
Normalized solvent-strength sensitivity for gradient separations: Comparing effective column lengths across
Szabolcs Fekete1, Christine Vo2, Wan-Chih Su2
1Waters Corporation, Geneva, Switzerland.
Journal of Chromatography. A
|May 6, 2026
Summary
A new dimensionless normalization for salt and pH gradients unifies retention modeling across chromatography modes. This universal solvent-strength sensitivity (SU) aids in designing faster separation methods for biomolecules like antibodies and DNA.
Area of Science:
- Analytical Chemistry
- Chromatography Science
Background:
- The linear solvent strength (LSS) model is effective for reversed-phase liquid chromatography (RPLC) retention prediction.
- Extending LSS to ion-exchange chromatography (IEX) necessitates normalizing the solvent-strength coordinate.
Purpose of the Study:
- To introduce a dimensionless normalization for salt and pH gradients in chromatography.
- To enable direct comparison of retention sensitivity across different chromatographic modes.
- To define a universal descriptor for retention behavior in gradient elution.
Main Methods:
- Developed a dimensionless normalization for salt and pH gradients.
- Defined universal solvent-strength sensitivity (SU) as the product of slope parameter and gradient span.
- Applied the SU descriptor to predict effective column length (Leff).
Main Results:
- Demonstrated applicability of SU for monoclonal antibodies (mAbs), DNA fragments, and oligonucleotides/mRNA.
- Validated the normalization using existing and new experimental data.
- Showcased SU's utility in designing ultrashort columns for high-throughput separations.
Conclusions:
- The proposed normalization offers a unified approach to retention modeling across gradient modes.
- Facilitates method transfer and accelerates analytical workflows for diverse biomolecules.
- Enhances rational design of chromatographic separations for complex biological samples.
Related Concept Videos
01:09Ion-Exchange Chromatography
Ion-exchange chromatography, or IEC, is a technique for separating ions based on their affinity for the stationary phase. The stationary phase is a cross-linked polymer resin with covalently attached ionic functional groups. The functional groups can be either positively charged (cation exchangers) or negatively charged (anion exchangers). A cation exchanger consists of a polymeric anion and active cations, while an anion exchanger is a polymeric cation with active anions. The choice of...
01:05High-Performance Liquid Chromatography: Elution Process
In High-Performance Liquid Chromatography (HPLC), the elution process is critical to the separation of analytes and the quality of chromatographic results. Elution describes how compounds move through the column and separate based on their interactions with the mobile and stationary phases. This process determines the resolution, peak shape, and retention times in the chromatogram, which are essential for identifying and quantifying components in complex mixtures. Understanding the elution...
01:11High-Performance Liquid Chromatography: Introduction
High-performance liquid chromatography(HPLC), formerly referred to as High-pressure liquid chromatography, is a powerful technique used to separate, identify, and quantify components in complex mixtures. The term "high pressure" refers to using high pressure to push the liquid mobile phase through the tightly packed columns.
In HPLC, two phases play a critical role in the separation process:
In HPLC, two phases play a critical role in the separation process:
01:17Gas Chromatography: Types of Columns and Stationary Phases
Gas chromatography (GC) relies on stationary phases to separate and analyze components in a sample. There are two main types of stationary phases: liquid and solid. Liquid stationary phases are non-volatile, thermally stable, and chemically inert liquids coated onto the column. Solid stationary phases are particles of adsorbent material, such as silica gel or molecular sieves.
For an analyte to remain on the column for a sufficient amount of time, it must exhibit some level of compatibility (or...
For an analyte to remain on the column for a sufficient amount of time, it must exhibit some level of compatibility (or...
01:15Optimizing Chromatographic Separations
Optimizing chromatographic separations is crucial for obtaining clean separations in a minimum amount of time. Optimization is required for several factors, including kinetic effects related to band broadening, plate height, capacity factor, and separation factor.
Band broadening refers to spreading solute bands as they travel through the column. This broadening can impact resolution. Plate height (H) represents the length required for one theoretical plate. A lower plate height corresponds to...
Band broadening refers to spreading solute bands as they travel through the column. This broadening can impact resolution. Plate height (H) represents the length required for one theoretical plate. A lower plate height corresponds to...
01:08Size-Exclusion Chromatography
In size-exclusion chromatography (SEC), also known as molecular-exclusion or gel-permeation chromatography, molecules are separated based on their sizes. This technique is important for separating large molecules such as polymers and biomolecules. The two classes of micron-sized stationary phases encountered in SEC are silica particles and cross-linked polymer resin beads. Both materials are porous, but their pore sizes vary significantly.
Silica particles offer advantages such as rigidity,...
Silica particles offer advantages such as rigidity,...