Polar polymer-immobilized stationary phase for aqueous reversed-phase liquid chromatography

Abstract

In this work, a polar stationary phase was prepared by thermal immobilization of poly(glycidoxypropylmethyl-co-dimethylsiloxane) onto silica particles to separate polar compounds using water-rich mobile phases. The retention properties of the stationary phase were characterized by the separation of Tanaka and NIST SRM® 870 test mixtures. The elution order of the compounds indicated the reversed-phase mode, but the stationary phase was less hydrophobic and with higher silanophilic activity than typical stationary phases. Polar compounds presented reasonable retention in the stationary phase and symmetrical peaks in the chromatograms, due to hydrophilic interactions with glycidoxy groups in the polymer side chain. The stationary phase was applied for the separation of small polar and ionizable compounds. The retention factors increased with the aqueous mobile phase component. So, all polar compounds were separated efficiently and eluted symmetrically under highly aqueous mobile phases, >90%. Per aqueous liquid chromatography was the principal separation mode of the new stationary phase, presenting as a green alternative to the hydrophilic interaction liquid chromatography mode for the separation of polar compounds.