Partitioning of Fatty Acids in Oil/Water Systems Analyzed by HPLC

Abstract

Abstract Surfactant/oil/water systems in which the surface‐active substance is a mixture of an undissociated fatty acid (FA) and its sodium salt soap, exhibit the typical phase behavior and the general emulsion phenomenology produced by a formulation scan. The phase behavior transition is induced by changing the FA concentration in the system at a fixed alkaline (NaOH) content in water, which results in a variable lipophilic acid/hydrophilic salt ratio. The partitioning is reported for different FA types (octanoic to myristic) and alcohol co‐surfactants between excess oil and water phases of Winsor three‐phase optimum formulation system. The concentrations are determined by using a method reported in a previous work to quantify the total acid fraction in each phase.