双功能聚合物基质阳离子交换固定相的制备及其在离子色谱中的应用

离子色谱是分离分析阳离子型化合物的重要手段之一。高效阳离子交换固定相的制备研究对离子色谱技术的发展具有重要的意义。该文以丙烯酸和顺丁烯二酸酐为单体,2-巯基乙基磺酸钠为巯基改性剂,提出了聚合物基质微球巯基改性自由基聚合修饰方法,用以制备新型双功能的阳离子交换固定相。该固定相以羧基和磺酸基为功能基,仅用简单的强酸淋洗液便可以实现常规阳离子的基线分离。利用色谱学模型,对金属离子和有机胺的保留行为进行了研究。采用梯度淋洗模式,可在24 min内实现10种阳离子的分离,表明固定相具有优异的色谱性能。"巯基-烯"修饰方法简单、高效。此外,通过调节巯基改性剂的比例能够实现对固定相交换能力的调控。

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.