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phase were not influence significantly by the presence of the other. The results they obtained are shown in Figure 11. The linear relationship between the distribution coefficient and the volume fraction of the respective solvent is clearly established. The distribution coefficient of n-pentanol between water and pure carbon tetrachloride was found to be about 2.2 and similar distribution coefficient for n-pentanol was predicted by calculation to be obtainable from a mixture containing 82%v/v chloroheptane and 18%v/v of n-heptane. The experiment for toluene was repeated using a mixture of 82 %v/v chloroheptane and 18% n-heptane mixture in place of carbon tetrachloride which was, in fact, constituted a ternary mixture comprising of toluene, chloroheptane and n-heptane. The chloroheptane and n-heptane, however, was always in the ratio of 82/18 by volume to simulate the interactive character of carbon tetrachloride. All the points for the n-heptane/n-chloroheptane mixtures fell on the

same source is available for a homologous series of aliphatic amines, alcohols, halogenated hydrocarbons etc. that can all be treated in the same way. The chlorinated hydrocarbons can be taken as another example. Retention data for the n-chloroalkanes taken over a temperature range of 76˚C to 88˚C on a n-C30 alkane stationary phase can also be examined thermodynamically. Employing the same procedure Log(V'r(T)) for the solutes n-chlorobutane, n-chloropentane, n-chlorohexane and n-chloroheptane were plotted against the number of methylene groups at each temperature. The slope (representing the methylene contribution (), the intercept for the methyl group () (taken from data for the n-alkane series which was also available on the same stationary phase and temperature range), and the intercept due to the interaction with the chlorine atom,  (taken as the difference between the actual intercept and that of the methyl group) were each plotted against the reciprocal of

inversely proportional to the volume fraction of either component providing there is no strong association between the components. This was experimentally demonstrated by Katz et al. (35) who employed a liquid/liquid distribution system using water and a series of immiscible solvent mixtures as the two phases and measured the absolute distribution coefficient of a solute for different mixtures. The solute they used was n-pentanol and the immiscible solvent consisted of mixtures of n-heptane andchloroheptane, n-heptane and toluene and n-heptane and heptyl acetate.  The two phase system was thermostatted at 25oC and, after equilibrium had been established, the concentration of solute in the two phases was determined by GC analysis. The results they obtained are shown in figure 46. It is seen that linear relationships between solvent composition and distribution coefficient was obtained for all three solvent mixtures simulating the results that Purnell and Laub obtained in their gas