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Zeta potential is a surface characteristic formed on the solid surface and liquid interface. It is an interesting way to describe the surface properties of materials; thus, a series of four homemade polar embedded stationary phases that contain phosphate groups incorporated into hydrophobic ligands were investigated according to surface zeta potential. Measurements were carried out using Zetasizer Nano ZS for the stationary phases suspensions prepared in various solvent and solvent binary mixtures. The negative zeta potential values were obtained for most cases due to negatively charged residual silanols and phosphate groups. However, in some solvents: tetrahydrofuran, isopropanol, and toluene zeta potential are positive. Additionally, it was observed that the zeta potential seems to be independent of the type of silica gel used for the stationary phase synthesis.

Industrial research, including pharmaceutical research, is increasingly using liquid chromatography techniques. This involves the production of large quantities of hazardous and toxic organic waste. Therefore, it is essential at this point to focus interest on solutions proposed by so-called “green chemistry”. One such solution is the search for new methods or the use of new materials that will reduce waste. One of the most promising ideas is to perform chromatographic separation using pure water, without organic solvents, as a mobile phase. Such an approach requires novel stationary phases or specific chromatographic conditions, such as an elevated separation temperature. The following review paper aims to gather information on stationary phases used for separation under purely aqueous conditions at various temperatures.

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.

The development of new home-made stationary phases involves their packaging procedure and is crucial to obtain satisfactory working parameters. The parameter that illustrates the quality of the packed bed is its efficiency measured as the height equivalent to the theoretical plate. According to the Van Deemetr's equation, it depends on three factors, but only one of them, eddy diffusion, does not depend on the linear flow velocity. Therefore, in order to obtain it as low as possible, it is necessary to focus on a good filling of the column. Among many parameters affecting the quality of column packing, in our work we have focused on the choice of slurry solvent. Novel stationary phases with an embedded phosphodiester group were investigated. The suspensions in 16 solvents and solvent mixtures were studied for their stability, aggregation, sedimentation, and viscosity comparison. The efficiency of the packed microcolumns and its comparison was determined by chromatographic analyses using a polar (thymidine) and a nonpolar compound (naphthalene). The results obtained led to the conclusion that for these stationary phases, the best slurry solvent is the one that aggregates the phase while maintaining stability and having high viscosity.