Study of solvent adsorption on chemically bonded stationary phases by microcalorimetry and liquid chromatography

Study of solvation processes on cholesterol bonded phases

“…A lower coverage density of bonded ligands implies relatively better solvation of the ligands by solvent molecules. This phenomenon was also confirmed by a modeling study [51] and microcalorimetric measurements [50].…”

“…nitrogen, oxygen) in the linkage of the cholesterol molecules which can establish preferential interactions with solvent molecules. Recent measurements confirms, that methanol may interact with residual silanols even the coverage density of bonded phase is high [50]. High surface coverage hamper penetration of methanol molecules to the silica surface which is observed on the Cosmosil Cholester column (the highest coverage and the highest water adsorption on the silanols).…”

Surface excess isotherms of organic solvent mixtures in a system made of liquid carbon dioxide and a silicagel surface

“…If we consider separately the alcohols, the maximum enrichment decreases from methanol, to ethanol and 2-propanol, a behavior connected with their higher affinity for silica surfaces [16]. The general enrichment of the organic modifier shows a behavior similar to that of these organic solvents on hydrophobic surfaces from their aqueous solution [17].…”

Linear Solvation Energy Relationships in the Determination of Specificity and Selectivity of Stationary Phases

“…All stationary phases were prepared in our laboratory. The synthesis was performed according to the reaction mechanism and the conditions described earlier: octadecyl in [24], alkylamide [25], cholesterolic [26], alkyl-phosphate [27], phenyl [28]. Figure 1 presents structures of chemically bonded stationary phases.…”

“…They were prepared on the basis of the same batch of silica gel Kromasil ® . Its physicochemical characteristic was published earlier in [24–27]. The received packing materials were packed into 125 × 4.6 mm I.D.…”