The partitioning and absorption mechanisms of retention in reversed-phase liquid chromtography (RPLC) were examined based on the free energy of transfer of a methylene group from organic aqueous mixtures to bulk hexadecane. Retention on monomeric bonded phases with octyl chains or longer are dominated by a partitioning-like mechanism. An adsorption-like mechanism contributes to retention in monomeric bonded phases with short bonded chains or with low surface coverage density. The retention mechanism becomes more adsorption-like as the bonded chains decrease.
Bibliographical noteFunding Information:
This work was supported by a grant from the National Science Foundation.
- Retention mechanisms
- Solvophobic theory
- Stationary phases, LC