SPECTROPHOTOMETRIC RESEARCH INTO INTERACTION NICKEL (II) WITH 1- (2- PYRIDYLAZO) -2- HYDROXY -4-MERCAPTOFENOL AND AMINOPHENOLS

Abstract

The complexation reaction of nickel with 1-(2-pyridylazo)-2- hydroxy-4-mercaptophenol (PAGMP) in the presence of aminophenols (AP) was studied by spectrophotometric methods. Out of aminophenols there were used 2-(N,N-dimethylaminomethyl)-4-methylphenol and 2-(N, N-dimethylaminomethyl)-4- chlorophenol. We revealed optimum conditions for formation and extraction of differently ligand compounds and determined proportions of components in the complexes. It found that the complexes were formed in a weakly acidic environment (pH 3.5-6.5). The maximum in the light absorption spectrum is observed at λ=620-650 nm. The molar coefficient of light absorption is ε=(2.3-2.5)×104 . The optimal condition for the formation and extraction of these compounds is the concentration (1.2-1.5)×10-3 M PAGMP and (2.4- 2.6)×10-3 M AP. The maximum optical density is obtained within 15 minutes. Nickel МLC extracts with PAGMP and AF are subject to Beer's law at concentrations of 0.5–18 μg/ml. Proceeding from the results obtained, the photometric methods for the determination of nickel in water and soil were developed.