Comp Chem Research Developments

September 8, 1999

Simulating Retention in Chromatography

Graduate student Marcus Martin (DOE Computational Science Graduate Fellow), Professor Ilja Siepmann and collaborator Mark Schure of Rohm and Haas have carried out a molecular simulation study of linear and branched alkanes in a helium-squalane gas-liquid chromatography system (see below for stereo image of the liquid phase). Accurate predictions of the retention characteristics of a solute molecule given only its structure and the experimental chromatographic conditions is the grand challenge for theoretical separation science.

This work represents a landmark for separation science because it is the first quantitative prediction of relative retention times based on statistical mechanical principles and transferable force fields; that is, neither the simulation algorithms nor the force field were specifically designed for studies of retention processes. In addition to predictions of retention times, performing a molecular simulation allows the team to provide microscopic insight into the retention mechanism. A manuscript describing this work has been submitted to the Journal of the American Chemical Society.