Spectrophotometric Determination of Aluminum(III) by the Solvent Extraction

Abstract

The extraction of aluminum(III)-Alizarin Red S(ARS)chelate with methyl isobutyl ketone (MIBK) in the presence of 1, 3-dibhenylguanidinium(DPG) salt has been investigated spectro-photometrically. The extracted species has an absorption maximum at abeut 525 nm, with a constant abserbance in the pH range from 5.5 to 5.9. For the absorbance of the association complex under the optimum conditions of pH, reagent concentrations and shaking time, Beer's gaw is obeyed up to 1.5 10"5 mo/1 aluminum in aqueous phase. The molar absorptivity is 2.90 10⁴l/mol cm at 525 nm. lt is found that the 1:2 aluminum-ARS chelate anion formS ion association complex of 1:2 molar ratio with DPG cation, and the complex is extracted from aqueous phase into organic phase.