INTERMOLECULAR INTERACTIONS INVOLVED IN SOLUTE RETENTION ON CARBON MEDIA IN REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Carbon adsorbents for RPLC separations are greatly underutilized due t o the poor chromatographic properties of the earliest commercially ava ilable materials and our limited understanding of solute interactions with the solid surface, Previously, we reported on the properties of a carbon surface prepared by vapor deposition on porous zirconia micros pheres. The resulting material is a new type of carbon sorbent with co nsiderably improved chromatographic properties, sere we present a fund amental study of the intermolecular interactions influencing solute re tention on these novel carbon phases under RPLC conditions, Retention on seven unique carbon phases has been correlated with solute descript ors of dispersion, dipolarity/polarizability, and hydrogen bond basici ty through the use of Linear solvation energy relationships (LSERs). I n stark contrast, conventional bonded phases do not show the large con tribution from dipolarity/polarizability that is observed on these typ es of carbon. The presence of this interaction indicates a distinct di fference between carbon and conventional bonded RPLC phases. Other res ults suggest that solvent sorption plays a significant role in control ling solute retention on carbon, In addition, we investigated the temp erature dependence of retention on carbon and found typical RPLC-like behavior.