Abstract
The effect of the third components α, α'-dipyridyl (α, α'-dip), ethylene diamine (Ed) and phenontroline (Phen) on the complexation of nickel (II) with 1-phenyl–2-(2-hydroxy–4- nitrophenylhydrozo)butanedione-1,3 was studied. NiR and mixed ligand (NiRα, α'-dip, NiREd and NiRPhen) complex compounds are formed at pH 6, 5, 4.5 and 5, respectively.The ratio of the reacting components in the composition of homogeneous and mixed ligand complexes was established and the interval of subordination to the Beer's law determined.The developed methodology was applied to specify nickel (II) in the river water.