Adsorption-driven retention in normal-phase chromatography with ternary mobile phases

Area of Science:

• Analytical Chemistry
• Chromatography
• Physical Chemistry

Background:

• Chromatographic retention is influenced by solute and solvent adsorptive properties.
• Understanding ternary mobile phase composition effects is crucial for optimizing separations.
• Existing models may not fully capture retention behavior in complex solvent mixtures.

Purpose of the Study:

• To develop a predictive model for retention in chromatographic systems using ternary mobile phases.
• To investigate the impact of mobile phase composition on solute retention.
• To establish simple relationships between retention parameters in ternary and binary solvent systems.

Main Methods:

• Development of a theoretical model based on adsorptive properties of solutes and solvents.
• Formulation of simple dependencies between retention parameters for ternary and binary mobile phases.
• Proposal of a linear relationship to predict capacity factors in ternary systems with fixed solvent ratios.
• Experimental validation across the entire concentration region of the ternary mobile phase.

Main Results:

• A model for chromatographic retention in ternary mobile phases was established.
• Simple relationships were derived to characterize retention in ternary versus binary solvent systems.
• A linear predictive model for capacity factor in ternary mobile phases was proposed and validated.
• Experimental data confirmed the theoretical predictions across diverse concentration ranges.

Conclusions:

• The proposed model accurately predicts solute retention in ternary mobile phases.
• The linear relationship provides a practical tool for estimating capacity factors.
• Understanding adsorptive properties is key to controlling chromatographic separations with mixed solvents.