The effect of the cation- interaction on the sorption of cationic amines to montmorillonite

Cationic amine functional groups are present in many pharmaceuticals, such as oxytetracycline and desvenlafaxine, which are increasingly released into the environment. Sorption, the accumulation of a chemical at the solid-water interface, influences chemical fate and human exposure. As such, this research focuses on cationic amine sorption to montmorillonite, an important component of soil systems. Past work with cationic amines suggested that more than one mechanism was responsible for sorption. Based on these findings, I decided to focus my project on determining the effect of the cation- interaction on the sorption of cationic amines. The cation- interaction (Figure 1) is an electrostatically driven intermolecular interaction between the center of the aromatic ring of one amine and the positive amine functional group (N and attached Hs) of another molecule.