Study of Influence of Salt Additives on Mixed Reverse Micelles via Reverse Microemulsion Chromatography and UV–visible Spectroscopy

Reverse micellar mobile phases based on poly(oxyethylene) (4) lauryl ether (Brij 30) and sodium bis(2-ethylhexyl) sulfosuccinate (AOT) were used as mobile phases in HPLC. The chromatographic behavior of the model compounds was studied on the basis of reverse micellar mobile phases modified by salt additives. The binding of o-nitroaniline (o-NA) to the micelles of Brij 30 was determined by UV–visible spectroscopy. The different influences of kosmotropic and chaotropic anions on the binding constant Kb was revealed. This may be controlled by the different arrangement of kosmotropic and chaotropic ions in the water core of reverse micelles.