1978 Volume 27 Issue 7 Pages 395-399
The authors have already reported a study on phase separation of three component systems composed of 1-butanol-water-cyclohexane and methyl isobutyl ketone-water-cyclohexane. In the present work, partition behaviors of heteropoly molybdic acids of phosphate and silicate have been investigated using these mixed solvents. As it was found that cyclohexane, the synergistic solvent, properly decreases the dielectric constant of the executive solvent of 1-butanol and methyl isobutyl ketone, the stepwise extraction of the respective heteropoly molybdic acid could be achieved in the appropriate conditions: in the presence of (4045)% cyclohexane. Cyclohexane functions not only to improve the phase separation of these three component systems, but also to increase the partition coefficient of an objective solute and/or to decrease the partition coefficient of interfering solutes. These facts mean that cyclohexane acts as a synergistic solvent in the present solvent extraction. In conclusion, such three component systems studied by the aid of phase diagrams could be effectively applied for a variety of extraction analyses.
