SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF IRON, COBALT. AND NICKEL BY PARTIAL LEAST SQUARES CALIBRATION METHOD IN MICELLAR MEDIUM

The simultaneous determination of Fe„ Co and Ni was carried out as 2-aminocyclo-i-pentene dithiocarboxylic acid (ACDA) complexes in the presence of an aqueous solution of cationic surfactant of cetyl trimethylammonium bromide (CTAB). The presence of micellar systems allows one to eliminate the previous solvent extraction step that is necessary for the determination of metal-ACDA complexes in the absence of micelles. This reduces the cost and toxicity of the method. A partial least-squares multivariate calibration method for the analysis of ternary mixtures of Fe. Co and Ni was developed. For individual determinations, molar absorptivities of 8.46 x 10 (Fe, 650nm). 4.76 x 10 (Co. 458 nm) and 2.61 x 10 (Ni, 538 nm), were obtained.