AbstractTernary diagrams for methyl oleate/hexane/acetonitrile and methyl palmitate/hexane/acetonitrile systems were constructed from equilibria data obtained at 20.0 and 30.4C. The diagrams varied significantly with temperature; both systems showed expanded regions of immiscibility at the lower temperature. Both the partition coefficient of the methyl ester and the mutual solubility of hexane and acetonitrile, at each temperature, varied with ester concentration in the system. At high ester concentration, an inversion of the phases was observed. The countercurrent distribution of these compounds, as influenced by these effects, is discussed.