Micellar mobile phase description

As a result of the increasing use of modifiers in MLC, the need for an adequate description of the retention in hybrid micellar mobile phases appeared. Khaledi et al. [7, 8] were the first which intended to model the retention of solutes in these systems. They assumed that the linear relationship between log k and the volume fraction of organic modifier, (p, followed in conventional RPLC over a small range of values of (p, was also valid in hybrid MLC at constant micelle concentration ... 

The equations that describe the retention on hybrid micellar mobile phases were first derived on a pure empirical basis. A further concern was to find an interpretation of these equations, based on physico-chemical properties. This permitted the improvement of the descriptive models, and the evaluation of the parameters of interaction between the three environments involved in MLC stationary phase, bulk water, and micelles, according to equilibria 8.1 and 8.2 [ 18]. The coefficients in eq. 8.26 were related to several parameters of retention. From the reciprocal of this equation ... 

Armstrong and Nome [1] proposed a three-phase (stationary phase, bulk aqueous solvent and micellar pseudo-phase) model, to explain the chromatographic behavior in an RPLC system of a solute eluted with a mobile phase containing a surfactant above the cmc. Such a treatment has allowed a theoretical description of MLC, and greater understanding and utilization of this chromatographic technique. 

II. 4. Micellar Bile Salt Mobile Phases a) Bile Salt Description and Properties... 

Analogously to chromatography, the capacity factor kP can be defined as the ratio of the residence times of the analyte molecule in the mobile (aqueous) and stationary (micellar) phases (Nemstian distribution). The mathematical description is based on the assumption that attainment of the distribution equilibrium takes much less time than the duration of the migration of the solute. The components involved should not show any interaction with the capillary wall. As in almost all cases where UV detection is... 

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