SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF COBALT AND NICKEL WITH THE REACTIVE 2,2'-DIPYRIDILKETONE PICOLINOYLHYDRAZONE

In aqueous ethanol cobalt(II) and nickel(II) react instantaneously with picolinoylhydrazone of 2,2'-dipyridilketone at acetate buffer (pH 4.9) to form strongly coloured complexes exhibiting absorption maxima at 410 and 385 nm, respectively. This behaviour has been made the basis of a rapid method for the simultaneous determination of these elements. The absorbances of the complexes have been found to be additive for all combinations of these elements in which the individual concentrations have been varied from approximately 0.1 to 2.5 ppm. A similar method in extract Cl3CH has been studied. Interference data are reported.