Stripping Voltammetric Determination of Inorganic Antimony Species in Natural Waters.

Abstract

In this paper stripping voltammetric techniques used for the determination of antimony species in water samples at trace levels are compared. A voltammetric behavior of Sb depends on the oxidation state of the element. For the determination of Sb(III) water samples without pretreatment were used. The content of total antimony was estimated after reduction of Sb(V) to Sb(III) with ascorbic acid in medium of 1 mol.l^-1 HCl. The antimony(III) was accumulated on a hanging mercury drop electrode either with electrochemical reduction to elemental antimony Sb(0) (ASV) or with adsorptive collection in the form of complexes with catechol and chloranilic acid (AdSV). The synthetic waters spiked with standard solutions of Sb(III) and Sb(V) were used for the testing of stripping voltammetric techniques. The relative standard deviations ranged from 0,9 to 9,2 % and the recoveries were > 90,7 % for both Sb species. Finally, the developed methods were successfully applied to the analysis of Sb in ground waters. Excellent agreement of our results of total Sb with those of HGAAS technique confirms the validity of stripping voltammetric methods for antimony determination.