ИСТИНА

The development of mixed-mode resins that can be used in suppressed ion chromatography (IC) and HILIC is a promising field of HPLC nowadays. Hydrophobic stationary phases based on copolymers of styrene with divinylbenzene (PS-DVB) are the most common in IC, however there are only a few examples of their application in HILIC. To provide the retention of highly polar compounds it is necessary to increase the hydrophilization degree of PS-DVB-based resins. The substrate shielding by covalently grafted polyethyleneimine (PEI) and subsequent quaternization of its amino groups with glycidol leads to the obtaining sufficiently hydrophilic anion exchangers that are suitable for simultaneous separation of weakly and strongly retained anions. Further increasing hydrophilicity of such stationary phases can allow the improvement of chromatographic characteristics of weakly hydrated hydrophobic anions and the applying them for separation of polar analytes by HILIC. The work proposes two approaches to increase the hydrophilicity of resins with grafted PEI: polymerization of glycidol in a functional layer in an alkaline medium and modification of PS-DVB by oxidizing double bonds on its surface.