Highly interference-free sensitized and sensitive spectrophotometric method for the determination of Cr(III) ion is described. The method is based on the reaction between Cr (III) ion and benzyl dioxime in micellar in the presence of non-ionic surfactant Triton X-100 has been performed. The absorbance is linear from 0.1 up to 25.0 μg ml−1 in aqueous solution. The repeatability (RSD) is 1.3% at a concentration of 1 μg mL−1 with molar absorption coefficient of 68,600 L mol−1 cm−1 and detection limit of 0.12 ng ml−1. The influence of reaction variables including pH, amount of ligand 2-(Phenyl)-4,5-Di (4-Methoxy Phenyl) Imidazole (PDMPI), type and amount of surfactant, complexation time and the effect of interfering ions, are investigated. The proposed methods have been applied to the rapid and simple determination of Cr (III) ion in the real samples successfully with recovery yield of almost 100%. The method does not need any separation or organic solvent extraction.
