Sampled voltammetry on an electrode array for the renewal of the electrode surface and the analytical solution during the analysis

Polarography with dropping mercury electrode has been widely used in electroanalysis. However, the method is less and less employed due to the toxicity of mercury. In this work, we have shown that it is possible to replace the dropping electrode by a working electrode array, allowing the renewal of the electrode surface and of the analytical solution during the analysis. This new concept has been demonstrated on copper analysis. Sampled current voltammetry has been carried out on an electrode array, giving rise to I vs. E curves with a limiting diffusion plateau. The principle can be extended to other electroanalytical methods as exemplified here with differential pulse voltammetry. Linear calibration curves have been obtained with both methods and a limit of detection of 2 × 10−5 mol L−1 has been reached for copper detection by differential pulse voltammetry.

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► New concept involving an electrode array to mimic dropping mercury electrodes.
► Sampled current voltammetry on an electrode array gives rise to I vs. E curves.
► Renewal of the electrode surface and of the solution in its proximity.
► Generalization to other modes as illustrated with differential pulse voltammetry.
► Electrochemical detection of copper.