In Figure 4.23, a single three-phase region exists and is given by the triangle in the center of the diagram. The point, (0.3, 0.4, 0.3) is at the center of the small triangle in the diagram and is located by following the red diagonal 60В° line at red 0.3 and the horizontal line at blue 0.4 or any combination of two of the coordinates ( A, B, C). A point on the diagram represents a composition that is specified in terms of mole fraction or weight fraction. Dashed-blue lines give the composition of phases in equilibium. Regions enclosed by the black lines show similar types of phase behavior. Schematic ternary phase diagram for a mixture of A, B and C. If heptane is the stationary phase, a gradient with increasing amounts of methanol, up to 80% v/v methanol, can be run without affecting the stationary phase. With this system, when heptane is the mobile phase, pure heptane can be used without pre-equilibrating it with the methanolвЂ“water stationary phase. In practice, if the separation can be carried out with the heptaneвЂ“methanolвЂ“water 1:1:1, v/v/v, system, it is possible to prepare one phase by just mixing equal amounts of methanol and water the other phase is pure heptane. Furthermore, if the water-to-methanol volume percentage ratio is higher than 20%, it can be considered that there is practically no heptane in the lower phase ( Fig. This means that whatever proportions of heptaneвЂ“methanolвЂ“water are mixed, the upper phase is always pure heptane (bottom right tube in Fig. 2.1 (bottom), all its tie-lines converge toward the heptane apex. The heptaneвЂ“methanolвЂ“water ternary system should be mentioned because it is extremely convenient for use in CCC. Compositions 1 and 5 will be prepared, in both cases and respectively, if the separation needs more mobile phase than the amount initially prepared. In contrast, Composition 4 is appropriate if the mobile phase is the organic lower phase.

Since the volume of mobile phase used for a separation is larger than the volume of stationary phase, Composition 2 will be prepared if the selected mobile phase is the aqueous phase. The amount of phases is different, but their compositions are identical. The chloroform-rich 13:7:4 system (Composition 3) separates in the 35% aqueous phase and 65% heavy organic phase ( Table 2.1, and right tube in Fig. The difference is that Composition 2 (rich in methanol and water) separates in 77% of the light aqueous phase and only 23% of the heavy chloroform-rich organic phase (left tube in Fig. The two systems belonging to the same tie-line separate into two phases that have exactly the same composition. It is very important to realize that a CCC separation performed with the 5:9:7, v/v/v, chloroformвЂ“methanolвЂ“water system will give exactly the same results as one done with the 13:7:4, v/v/v, system. Whatever liquid composition belonging to the tie-line is prepared, the aqueous phase is Composition 1 and the organic phase is Composition 5, both on the binodal curve on both ends of the tie-line. The only difference is the phase volume ratio. So, by definition, they separate into two liquid phases that have exactly the same compositions.

Five particular compositions are shown in the diagram: Table 2.1 lists their respective compositions, and they all belong on the same tie-line. Figure 2.1 (top) shows the methanolвЂ“chloroformвЂ“water ternary phase diagram with the tie-lines in the biphasic domain. Here, we shall indicate how they should be used to minimize the solvent consumption.

Ternary phase diagrams are used to represent all possible mixtures of three solvents they are described in Chapter 3.

Ternary diagram heaviest component