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Journal of Analytical Methods in Chemistry
Volume 2012, Article ID 265687, 7 pages
Research Article

Use of Hg-Electroplated-Pt Ultramicroelectrode for Determining Elemental Sulphur in Naphtha Samples

1Departamento de Química Inorgânica, Instituto de Química, Centro de Tecnologia, UFRJ, Avenida Athos da Silveira Ramos 149, Bloco A, Laboratório 634A, Cidade Universitária, 21941-909 Rio de Janeiro, RJ, Brazil
2Instituto de Química de São Carlos, Universidade de São Paulo, Avenida do Trabalhador Saocarlense 400, 13566-590 São Carlos, SP, Brazil

Received 4 November 2011; Revised 30 January 2012; Accepted 31 January 2012

Academic Editor: Orawon Chailapakul

Copyright © 2012 Carlos Eduardo de Andrade et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


This paper describes the applicability of a Hg-electroplated-Pt ultramicroelectrode in the quantification of elemental sulphur in naphtha samples by square-wave voltammetry. A reproducible deposition methodology was studied and is reported in this paper. This methodology is innovative and relies on the quality of the mercury stock solution to obtain reproducible surfaces required for the analytical methodology. All analyses were performed using a Hg-electroplated-Pt ultramicroelectrode (Hg-Pt UME) due to the low sensibility of such devices to ohmic drops in resistive solutions. The responses of the peak areas in voltammetric experiments were linear in all of the range studied. The method developed here is accurate and reproducible, with a detection limit of 0.010 mg L−1 and a good recovery range for both standard solutions of elemental sulphur (85 to 99%) and real naphtha sample (79%). These results attest to the potential for the application of this electroanalytical methodology in determining elemental sulphur in naphtha samples containing mercaptans and disulphides.