Analysis of the solvent strength parameter (linear solvent strength model) for isocratic separations in reversed-phase liquid chromatography

Revisiting the dependence of retention factor on the content of organic component in the mobile phase in reversed‐phase HPLC

“…The results from different published studies showing differences in the values of k w for methanol compared to acetonitrile in the mobile phase (see, e.g., [49]) were expected in the view of the hypothesis of this study that the organic solvent does not have only a role in changing the properties of the mobile phase but is also competing with the analyte in the partition process and/or is modifying the nature of the stationary phase. The values for k w were generated using a mathematical extrapolation to ϕ = 0, while the measurements were performed on the column with a specific organic layer of molecules adsorbed on its stationary phase surface and not bare stationary phase as it would be assumed for ϕ = 0.…”

Selectivity comparison of acetonitrile‐methanol‐water ternary mobile phases on an octadecylsiloxane‐bonded silica stationary phase

“…When categorizing solvents into groups with comparable physicochemical characteristics in RPLC systems, two aspects must be considered: solvent strength and selectivity. The solvent strength parameter, S AB , estimates a solvent's capacity to elute solutes from a certain chromatographic system [14,19,20]. Equation ( 2) describes the relationship between the retention factor (log k) and the solvent strength parameter (S AB ) for an RPLC system (in a confined range of mobile phase compositions), where the term ϕ is the volume fraction of organic solvent and k w is a measure of the retention factor of a solute when water is the mobile phase [21].…”

“…The estimation of S AB for RPLC systems is outlined in two recent reports [14,19]. The solvent strength parameter, S AB , for the ACN:MeOH (1:1) Luna C18 (2) chromatographic system was estimated using exact protocols [14,19].…”

“…The estimation of S AB for RPLC systems is outlined in two recent reports [14,19]. The solvent strength parameter, S AB , for the ACN:MeOH (1:1) Luna C18 (2) chromatographic system was estimated using exact protocols [14,19]. For comparison purposes, the solvent strength parameter, S AB , values for ACN, acetone, tetrahydrofuran, 2-propanol, and methanol on a Luna C18 (2) stationary phase were taken from a literature source [19].…”

“…The solvent strength parameter, S AB , for the ACN:MeOH (1:1) Luna C18 (2) chromatographic system was estimated using exact protocols [14,19]. For comparison purposes, the solvent strength parameter, S AB , values for ACN, acetone, tetrahydrofuran, 2-propanol, and methanol on a Luna C18 (2) stationary phase were taken from a literature source [19]. Summarised S AB values for the Luna C18 (2) phase for solvent systems ACN:MeOH (1:1), ACN, acetone, tetrahydrofuran, 2-propanol, and methanol are given in Table S2.…”