Departamento 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.
J Anal Methods Chem. 2012;2012:265687. doi: 10.1155/2012/265687. Epub 2012 Apr 3.
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.
本文描述了镀汞铂毫微电极在通过方波伏安法定量测定石脑油样品中元素硫的适用性。本文研究并报道了一种可重现的沉积方法。该方法具有创新性，依赖于汞储备溶液的质量，以获得分析方法所需的可重现表面。由于此类设备对电阻溶液中的欧姆降非常敏感，因此所有分析均使用镀汞铂毫微电极（Hg-Pt UME）进行。在所有研究范围内，伏安实验中峰面积的响应均呈线性。所开发的方法准确且可重现，检测限为 0.010 mg·L(-1)，对于元素硫标准溶液（85%至 99%）和实际石脑油样品（79%）均具有良好的回收率范围。这些结果证明了该电分析方法在测定含硫醇和二硫化物的石脑油样品中元素硫的应用潜力。
