Distribution of Cobalt (II) ions from aqueous media into chloroform solution of N,N’-ethylenebis (4-propionyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-oneimine) (H2PrEtP) Schiff base

F. C. Nwadire, V. I. E. Ajiwe, P. A.C. Okoye


Liquid-liquid extraction of cobalt (II) ions have been carried out using 0.05 M solution of N,N’-ethylenebis (4-propionyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-oneimine) (H2PrEtP) Schiff base in chloroform[RNM1] . Various parameters for the extraction such as effect of pH, concentrations of the extractant, cobalt (II) ion , phase ratio and synergistic effect of 4-propionyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one (HPrP) have  been investigated and optimized. Extraction with single ligand was observed to have a pH1/2 of 7.05 with percentage extraction of 53.24 % corresponding to logD value of 0.0563, and optimum pH of 9.25 with percentage extraction of 98.43 %, logD value of 1.7971. The synergistic effect of HPrP on the extraction significantly lowered the pH1/2 from pH 7.05 (near neutral) to pH 6.25 (slightly acidic) with percentage extraction of 52.60 % corresponding to logD value of 0.0451. Optimum extraction of 99.30 was observed at pH 8.26 when the mixed ligands, H2PrEtP and HPrP were used.  The extraction of cobalt (II) ions  increased rapidly as the concentrations of the ligands H2PrEtP increased from 2.5×10-3 M to 4.0×10-2 M and that of HPrP from 2.5×10-3 M to to 2.5×10-2. Variation of the metal concentration did not have much effect on the extractions, hence the percentage extraction was relatively high over all the metal concentrations studied.

 [RNM1]The title suggests that chloroform is the solvent.

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DOI: http://dx.doi.org/10.17628/ecb.2015.4.186-189


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