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Following the idea of green chemistry, especially green analytical chemistry, a series of stationary phases was synthesized. The obtained materials connect polar and hydrophobic groups in the structure of bonded ligands. These specific surface properties provide the stability of the stationary phase in pure water as a mobile phase. To confirm the solvation ability in purely aqueous mobile phases, excess isotherms of water and acetonitrile were determined. Further, the mixtures of nucleosides, nucleic bases and purine alkaloids were applied to test the separation selectivity of stationary phases in purely aqueous conditions at ambient temperature without any additives to the mobile phase. Among the four tested stationary phases, it is possible to find one for separation of each group of analytes that offers selective separation in reasonable time. The presented data confirms that it is possible to synthesize stationary phases for the separation of target mixtures in pure water conditions. [ABSTRACT FROM AUTHOR]

Solvation processes on polar embedded stationary phases were investigated by determination of excess isotherms in binary acetonitrile/water mobile phase. The obtained results indicate the competitiveness of acetonitrile and water adsorption on heterogeneous surfaces of chemically bonded stationary phases. The calculation of excess isotherm as a volume of excessively accumulated solvent confirms the competitiveness of solvents' adsorption in qualitative and quantitative meaning. Corresponding excess isotherms of water and acetonitrile are symmetrical with respect to the x‐axis. It confirms that the displaced volume of acetonitrile is replaced by an equal volume of water and vice versa. Additionally, fitting the two‐site adsorption model to experimental data provides quantitative values with low experimental errors. The obtained results confirm the advantage of volumetric assumption of excess adsorption over direct adsorption layers of solvents, which is commonly postulated. [ABSTRACT FROM AUTHOR]

• Stationary phases with an integrated polar group were characterized. • Chromatographic test allows to compare phases with different embedded group. • Diol-based stationary phases exhibit negative values of zeta potential. • Zeta potential is in agreement with cation- and anion-exchange properties. The chromatographic properties of six non-commercially available stationary phases with ester or phosphodiester functional groups embedded into alkyl chain were studied. Zeta potential values of stationary phases suspended in water, organic solvent and their mixtures were measured. Moreover, the selectivity coefficients were calculated on the basis of the retention factor for the test solutes. Separations were performed under hydrophilic interaction liquid chromatographic conditions. Hydrophobic and polar properties of the investigated columns were compared. Based on the chromatographic properties, polar embedded packing materials were classified. Also two phases with different spacer but the same embedded polar group and alkyl chain (Amino-P-C18 and Diol-P-C18) were used for comparison with homemade materials. Amino-P-C18 stationary phase exhibits positive values of zeta potential which is in accordance with the observed anion exchange properties. The highest negative values of zeta potential were observed for Diol-P-C18, together with cation exchange properties. The highest methylene selectivity, polar selectivity and configurational selectivity were observed for the stationary phase with an ester bond and a phenyl group. [ABSTRACT FROM AUTHOR]