Extraction And Thermodynamic Study Of Cobalt From Aqueous Solutions By Using Of New Organic Reagent5-[(3,4,5-Trimethoxyphenyl) Methyl]Pyrimidine-2,4-Diamineazo]-1-N-(4-Hydroxyphenyl) Acetamide

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 λ_max= 523 nm has been used for determining the concentrations of Co²⁺ in different samples.