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Molecular Mechanisms Underlying Solute Retention at Heterogeneous Interfaces
Krystel El Hage1, Prashant Kumar Gupta1, Raymond Bemish2
1Department of Chemistry, University of Basel , Klingelbergstrasse 80, 4056 Basel, Switzerland.
The Journal of Physical Chemistry Letters
|September 6, 2017
Summary
Understanding adsorption and desorption in reversed-phase liquid chromatography (RPLC) at the molecular level is crucial. This study reveals that retention typically involves both partitioning and adsorption, guiding better RPLC column design.
Area of Science:
- Analytical Chemistry
- Physical Chemistry
- Computational Chemistry
Background:
- A molecular-level understanding of adsorption/desorption in reversed-phase liquid chromatography (RPLC) is lacking.
- This knowledge gap hinders rational column design and accurate prediction of column selectivity.
- Current computational approaches for RPLC selectivity prediction are limited.
Purpose of the Study:
- To investigate the adsorption thermodynamics of benzene derivatives in RPLC at an atomistic level.
- To provide a quantitative microscopic understanding of retention mechanisms.
- To compare simulation results with experimental data for validation.
Main Methods:
- Utilized state-of-the-art, validated force fields.
- Employed free-energy simulations for detailed thermodynamic analysis.
- Investigated adsorption thermodynamics of benzene derivatives.
Main Results:
- Found that pure partitioning or pure adsorption is rare in RPLC.
- Observed a typical stabilization of ~1 kcal/mol on the surface.
- Identified a partitioning trough before mobile phase incorporation.
Conclusions:
- Provided a quantitative microscopic understanding of RPLC retention mechanisms.
- Established a rational basis for developing improved computational models.
- Informed the design of RPLC columns for specific applications.
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