ИСТИНА

Hydrophilic interaction liquid chromatography (HILIC) is a modern promising method for the separation and determination of polar compounds. The retention mechanism in HILIC is complex and still not fully understood. It is considered that adsorption, partitioning, and electrostatic interactions may contribute simultaneously to retention. In the case of mixed-mode stationary phases based on hydrophobic polymer substrate, additionally hydrophobic and π-π interactions take place. Understanding the processes occurring in the chromatographic system makes it possible to find new approaches for characterization of adsorbents, and to control the separation efficiency and selectivity in HILIC mode. In this work, a set of test ions was selected: p-toluenesulfonate, alkylsulfonates, chloride, nitrate, single- and double-charged inorganic cations. Their retention mechanism was studied for silica- and poly(styrene-divinylbenzene)-based (PS-DVB) stationary phases (SP) with predominant anion-exchange properties. The realization of different types of interactions were studied using models derived for other chromatography modes. This work was supported by the Russian Science Foundation (project No 20-13-00140).