Extractive spectrophotometric determination of cobalt (II) using Cyanex reagents

Cyanex reagents form coloured complexes with Co(II) in the organic phase in presence of ammonium acetate. Their absorption maxima are observed at 632, 728.5 and 672.5 nm for Cyanex 272, 302 and 301, respectively. The optimum extraction conditions were developed by studying various parameters such as acetate concentration, reagent concentration, period of equilibration and effect of various diluents. The nature of the extracted species was determi ned by log D - log C plots, The method was further extended for analysis of Co(II) in real samples, The reproducibility of the proposed method was fou nd to be +/- 1.1%.