Adsorption of 1-pentanol on alkyl-modified silica and its effect on the retention mechanism in reversed-phase liquid chromatography

Interfacial tension effects of nonionic surfactants in reversed-phase liquid chromatography

“…Presumably, the same abbreviated model (eq 2) could also be used in the case of an uncharged surfactant (31) for which the dii term of eq 1 would be similarly unnecessary. Thus, the intent of this paper is to investigate the retention behavior of negatively charged, positively charged, and zwitterionic solutes in reversed-phase systems containing nonionic surfactants as eluent modifiers to illustrate the interfacial tension portion of the Stranahan model (23).…”

n-Alkyldimethylammonium propanesulfonates as stationary phase modifiers in reversed-phase liquid chromatography

“…Such a change was not observed. Initially the model of Wahlund and Beijeresten (27) was employed in which the retention of solutes in the presence of 1-pentanol could be understood based upon the surface coverage of 1-pentanol and two partition coefficients, one to the native stationary phase and one to the pentanol. Plotting k' for the solutes vs. (determined by breakthrough curves) of C12DAPS yields nonlinear plots in most instances indicating that the system being studied is more complex than a simple two-site stationary phase system in which one phase replaces the other as the mobile phase additive adsorbs.…”

Stationary-Phase Contribution of 1-Propanol Organic Modifier to Changes in Sorption of 1-Hexanol on an ODS-Bonded Phase

“…The fact that alkyl bonded phases preferentially sorb the organic modifier solvent from a mixed aqueous/organic mobile phase is now also widely accepted. − However, the role of the sorbed modifier remains controversial. Some workers hold the view that organic modifier in the mobile phase changes the solvent strength of the mobile phase and that organic modifier sorbed into the stationary phase changes the sorbent properties of the stationary phase, ,− by changing the space available for sorbing the solute 22,25,26 and/or by changing the sorbent strength of the stationary phase. − , Other workers hold the view that, while organic modifier is present in both phases, it affects only the solvent properties of the mobile phase and has very little effect on the sorbent properties of the stationary phase. , …”