Polarographic investigation of reduction process of some azodyes and their complexes with rare earths.

The voltammetry behavior of six azodyes (tropeolin 0, tropeolin 00, tropeolin 000, magnezon, eriochrome black T, arsenazo I) with various structures of the interface circuit and substituents in o,o'-positions, and their rare earth (RE) complexes was investigated in detail. The process of complex formation of RE(III) with some o,o'-hydroxyazodyes was studied. The reduction mechanism of o,o'-disubstituted azodyes and their complexes with RE(III) was offered. It was confirmed that all investigated compounds and complexes are adsorbed on the surface of the dropping mercury electrode. The possibility of voltammetric determination of azodyes in a water environment was shown. The results of the research were used for determination of rare earths in inorganic materials.