Univariate and Multivariate Optimization of Spectrophotometric Determination of Europium (III) in Pure Form and Synthetic Sample

Abstract

    Two different approaches, univariate and multivariate (simplex method), have been used to obtain the optimum conditions for the quantitative Spectrophotometric determination of Eu3+ using Solochrome violet RS (3-Hydroxy-4-(2-hydroxy phenyl azo) naphthalene -1sulfonic acid) (SVRS) as a chromogenic reagent. The investigation shows that Eu3+ ion forms a wine-red complex with SVRS in alkaline buffer solution having a maximum absorbance at 464 nm against reagent blank.       Calibration graphs obtained under univariate and simplex were found to be linear in the range of (0.30-8.0) µg/ml with detection limit 0.061µg/ml and molar absorptivity of 9877.66 L/mol.cm and (0.40-10.0)µg/ml with detection limit 0.055µg/ml and molar absorptivity of 10759.05 L/mol.cm respectively. The stoichiometric composition of the formed Eu-SVRS chelate complex is 1:4 (Metal:Ligand). Effect of the presence of some metal ions as interferences was studied and the method has been applied successfully to the determination of cited ion in synthetic sample.