Abstract:

The extraction of Co2+ ions from the aqueous phase bynew laboratory prepared azo derivation as complex agent accordingly, 5-[(3,4,5-trimethoxyphenyl)methyl]pyrimidine-2,4-diamineazo]-1-N-(4-hydroxyphenyl)acetamide reagent (L) has displayed adequate conditions for this extracting process under  pH=9, and shaking time of 10 minutes and 30 µg concentration of Co2+ ion.  The investigation of organic solvent's influence has shown no linear relation between the distribution ratio for the extraction of Co2+ion and dielectric constant (ε) of most used organic solvents. Nevertheless, there was an influence on the organic solvent structure in extracting Co2+ ion and distribution ratio (D) values. Stoichiometric studies have clarified the most potential structure of the ion-pair complex extracted for Co2+ with a 1:1 ratio. The complexation reaction and the extraction thermodynamic both were in the exothermic phase. Using the electrolyte was given a perfect enhancement in extraction efficiency with higher extraction efficiency charge as a function of the ionic diameter of electrolyte cation for the smallest ionic diameter. Based on the study of the interference effect, all cations have shown an apparent interference with Co2+. Still, in different levels of affinity, with the organic reagent L solvent extraction as a sensitive and selective method was used for spectrophotometric determination of Co2+ in miscellaneous samples. The digestion of the samples was based on the dry digestion method. The prepared calibration curve at λmax= 523 nm has been used for determining the concentrations of Co2+ in different samples.

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