Molecular Mechanisms Underlying Solute Retention at Heterogeneous Interfaces

作者：El Hage Krystel; Gupta Prashant Kumar; Bemish Raymond; Meuwly Markus^*

来源：Journal of Physical Chemistry Letters, 2017, 8(18): 4600-4607.

DOI：10.1021/acs.jpclett.7b01966

Despite considerable effort, a molecular-level understanding of the mechanisms governing adsorption/desorption in reversed-phase liquid chromatography is still lacking. This impedes rational design of columns and the development of reliable, computationally more efficient approaches to predict the selectivity of a particular column design. Using state-of-the art, validated force fields and free-energy simulations, the adsorption thermodynamics of benzene derivatives is investigated in atomistic detail and provides a quantitative microscopic understanding of retention when compared with experimental data. It is found that pure partitioning or pure adsorption is rather the exception than the rule. Typically, a pronounced similar to 1 kcal/mol stabilization on the surface is accompanied by a broad trough indicative of partitioning before the probe molecule incorporates into the mobile phase. The present findings provide a quantitative and rational basis to develop improved effective, coarse-grained computational models and to design columns for specific applications.

• 出版日期2017-9-21