Selection of reagents for voltammetric analysis of samples containing simultaneously Al(III), Ga(III), In(III), Sc(ІІІ) or REE(ІІІ)

Chem. Met. Alloys 8 (2015) 10-15

https://doi.org/10.30970/cma8.0297

Liliya DUBENSKA, Sofija TVORYNSKA, Solomiya PYSAREVSKA, Julija RAK

The possibility of simultaneous polarographic determination of two metals with azo dyes (eriochrome blue SE, kalces, eriochrome red B, eriochrome black T) was studied. The following metals were investigated: Al(III), Sc(III), Ga(III), In(III), and REE(III). The optimal conditions for the determination of different combinations of these metals were established. The main factor determining the possibility of simultaneous analysis is the pH of the medium, and appropriate values of pH for the determination of different pairs of M(III) by linear sweep polarography are proposed. Other factors, like the amount of azo dye, were also analyzed. The polarographic methods elaborated here were used in the analysis of alloys. The results obtained by the polarographic method were in good agreement when different azo dyes were used, and with the results obtained by independent spectrophotometric methods. The reported polarographic methods can be used for precise and accurate simultaneous determination of two metals with similar properties and is twice faster than known spectrophotometric methods, which require a preliminary separation step.

Polarograms in EBSE solution with an aliquot of Ho−Zn−Al alloy (1) and with a standard solution of Ho(III) (2).

Keywords

Rare earth elements / Alloy / Azo dye / Polarography / Spectrophotometry