Polarographic investigation of reduction processes of gallium(III) complexes with some o,o'-dihydroxysubstituted azo dyes

Chem. Met. Alloys 2 (2009) 194-201

https://doi.org/10.30970/cma2.0107

Solomiya PYSAREVSKA, Liliya DUBENSKA, Nataliya SHAJNOGA, Halyna LEVYTSKA

The voltammetric behaviour of Ga(III) complexes with o,o'-dihydroxysubstituted azo dyes (eriochrome red B (ERB), eriochrome black T (EBT), calcon (Calc), and kalces (Klc)) was investigated using cyclic linear-sweep voltammetry. Two new reduction peaks caused by reduction of the Ga(III)–azo dye complex compounds were registered on the voltammograms. The effect of pH, the concentration of azo dye and Ga(III) ions, and the sweep rate on the peak current was studied. The peak current changed linearly with increasing gallium concentration. New methods were proposed for the determination of metal ions. The detection limits were 2.0×10^‑7 M for the Ga(III)–ERB complex, 1.0×10^‑6 M for the Ga(III)–EBT and Ga(III)–Calc systems, 5.3×10^‑7 M for the Ga(III)–Klc complex based on the first peak and 9.1×10^‑7 M for the same system but based on the second peak. The proposed methods were tested on the determination of gallium in intermetallic compounds of the Zn–Ga and Sm–Ga systems and in a Gd₃Sc₂Ga₃O luminophore.

Cyclic voltammograms of 4×10^-5 М (Іа) ERB, (ІІа) EBT, (ІІІа) Klc, (IVа) Calc and (Іb) ERB–Ga(III), (IIb) EBT–Ga(III), (IIIb) Klc–Ga(III), (IVb) Calc–Ga(III) complexes, C_Ga(III)=C_{azo dye}=4×10^-5 М.

Keywords

Gallium / Azo dye / Voltammetry / Reduction / Dropping mercury electrode