[Preparation of difunctional polymer-based cation exchangers and their application in ion chromatography]

Ion chromatography (IC) is one of the most important means for the separation and analysis of cationic compounds. Research on high-performance cation exchangers is of great significance for the advancement of modern IC techniques. Herein we proposed a newly developed modification method for polymer-based particles, based on thiol-radical-mediated polymerization. Specifically, acrylic acid and maleic anhydride were used as monomers and sodium 2-mercaptoethanesulfonate was used as the thiol modifier to prepare novel difunctional cation exchangers, functionalized with both carboxylic and sulfonic groups. With simple strong acid eluents, typical cations were well separated with good resolution. The retention behaviors of metal cations and organic amines on the cation exchangers were investigated using multiple chromatographic models. The good performances of the cation exchangers were also demonstrated by the gradient separation of ten cations within 24 min. The new method was easy to perform with high efficiency. Additionally, the cation exchange capacities of the cation exchangers were easily modulated by adjusting the initial content of the thiol modifier.