Optimization of the extraction of iron(II) from water into cyclohexane with hexafluoroacetylacetone and tri-n-butyl phosphate.

The extraction of iron(II) from water into cyclohexane with hexafluoroacetylacetone (HHFA) and tri-n-butyl phosphate (TBP) was optimized by using a simplex algorithm; pH, [HHFA], [TBP], and mixing time were varied. A central composite design was employed to examine in detail the region of the apparent optimum. Regression analysis of the central composite data demonstrated that in the region of the optimum, the response was essentially unaffected by small variations in the levels of the factors investigated.