REQUIMTE, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Portugal.
Anal Chim Acta. 2011 Oct 3;703(1):1-7. doi: 10.1016/j.aca.2011.07.022. Epub 2011 Jul 23.
In this work, a simple, rapid, reliable and low cost method for simultaneous electrochemical determination of As, Cu, Hg and Pb ions, on a vibrating gold microwire electrode combined with stripping voltammetry, is described for the first time. The multi-element detection was performed in the presence of oxygen by differential pulse anodic stripping voltammetry (DPASV) in HCl 0.1 M with NaCl 0.5 M. This media was found optimum in terms of peak resolution, peak shape and sensitivities, and has a composition similar to seawater to which the method could potentially be applied. The gold microwire electrode presented well defined, undistorted, sharp and reproducible peaks for trace concentrations of Cu, Hg and Pb and As presented a reproducible peak with a small shoulder. Using a gold vibrating microwire electrode of 25 μm diameter and 30s deposition time, the detection limits of As, Cu, Hg and Pb were 0.07, 0.4, 0.07 and 0.2 μgL(-1), respectively. Possible effects of Al, Cd, Cr, Fe, Mn, Ni, Sb and Zn were investigated but did not cause any significant interferences. Finally, the method was applied for the simultaneous determination of these four metals in unpolluted river water samples and the results were validated by Atomic Absorption Spectroscopy with Electrothermal Atomization (AAS-EA) or by Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
本文首次描述了一种在金微丝电极上结合溶出伏安法，用于同时电化学测定砷、铜、汞和铅离子的简单、快速、可靠和低成本的方法。多元素检测是在含有氧气的条件下，在 0.1 M HCl 中，用 0.5 M NaCl 进行差分脉冲阳极溶出伏安法（DPASV）进行的。就峰分辨率、峰形和灵敏度而言，该介质是最佳的，且其组成与海水相似，该方法可能适用于海水。金微丝电极对痕量浓度的 Cu、Hg 和 Pb 呈现出定义良好、无变形、尖锐且可重现的峰，而 As 则呈现出可重现的小肩峰。使用直径为 25μm、沉积时间为 30s 的金振动微丝电极，As、Cu、Hg 和 Pb 的检测限分别为 0.07、0.4、0.07 和 0.2μg/L。研究了 Al、Cd、Cr、Fe、Mn、Ni、Sb 和 Zn 的可能影响，但没有引起任何显著的干扰。最后，该方法应用于未受污染河水样品中这四种金属的同时测定，并通过原子吸收光谱法（AAS-EA）或电感耦合等离子体质谱法（ICP-MS）进行验证。
