Silica gel with covalently immobilized imidazolium salt as a new stationary phase for ion chromatography

Abstract

The development of new anion-exchange stationary phases with improved selectivity and performance is one of topical problems in modern ion chromatography. Various classes of organic compounds are used as surface modifiers of the stationary phase matrix. In recent years, there is an increased interest in the use of ionic liquids allowing one to vary the nature of cation moiety in a wide range, which provides a way to control properties of materials on their basis. Earlier, our team has prepared and characterized silica gel with covalently immobilized imidazolium salt (with a particle size of 40-60 µm) and studied its ion-exchange characteristics in the solid-phase extraction of Pd(II) in chloride media. It seemed interesting to obtain similar material with a particle size of 8-12 µm and to determine whether it can be used as a stationary phase in ionexchange chromatography.The research object was a covalently modified silica gel:

Silica gel functionalized with imidazolium group via click chemistry – new stationary phase for ion chromatography

“…A mixture of Cl -, NO2 -, NO3 -, I -, and SO4 2anions was chosen as the model. The working parameters for chromatographic separation were chosen as follows: the eluent was HOOCC6H4COOK with C = 2.5 mM and pH = 4 [22].…”

Imidazolium-Modified Silica Gel for Highly Selective Preconcentration of Ag(I) from the Nitric Acid Medium

“…Currently, there is growing interest in the preparation of such materials based on different forms of silica [31][32][33][34]. Covalent immobilization of ionic liquids is often carried out on the surface of commercially available pre-functionalized silica gels to obtain new stationary chromatographic phases for the separation of amino acid mixtures and different organic and inorganic anions [35][36][37][38].…”