Study of partition models in reversed-phase liquid chromatography based on measured mobile phase solute activity coefficients

New insights on the retention mechanism of non-polar solutes in reversed-phase liquid chromatographic columns

“…The hold-up time, t 0 , was measured by injection of 0.01% KBr [27,28]. These values of t 0 were further verified by indicative measurements using water instead of KBr as the t 0 marker [22]. The values of t 0 determined at each column and eluent composition given in Tables 1-4.…”

“…Note that a test similar to point (i) has been proposed by Cheong and Carr [22]. (b) If the adsorption mechanism is valid in a reversed-phase column, then we have [1]:…”

“…In particular, we examined the retention behaviour of benzene, toluene, ethylbenzene and propylbenzene in a LiChrospher 100 RP-18 column using the data reported by Bosch et al [33] and in a Hypersil ODS column using Cheong and Carr's data [22]. If the case of MeOH is excluded, the results of the application of the tests suggested in this paper to the literature data are in general similar to the above results indicating both the validity of these results and their independence of the particular type of the fact that the distance of the F versus x curves for both toluene and ethylbenzene in MeOH and ACN is about 0.6, a value that is equal to the corresponding distance found in our plots of Figs.…”

“…Plots of S vs.x for B (᭹), T (᭡), EB (᭢) and PB (᭜) in the four modifiers shown in the figure. They have been calculated from data obtained by means of a LiChrospher 100 RP-18 column (MeOH, ACN)[33] and a Hypersil ODS column (iPrOH, THF)[22].…”

A generalized approach to thermodynamic properties of biomolecules for use in bioseparation process design

“…(3.17) is the ratio of activity coefficients on the stationary phase, consequently most difficult to access because it is virtually impossible to directly measure the activity coefficients of macromolecules in the stationary phase. Some researchers believe that the activity coefficient of macromolecule in the stationary phase remains practically constant for a particular resin/solvent combination while varying the mobile phase composition [66]. In that case, the last term in Eq.…”