How to optimize the analytical performance of differential pulse voltammetry: one variable at time versus Design of Experiments

Differential pulse voltammetry has often been considered one of the most suitable techniques for electroanalytical applications. However, the voltammetric parameters used are often chosen without a proper examination of their effect on the resulting response. In this lab experiment, the students are guided to a more informed choice of the electrochemical parameters to apply depending on the application sought. In the first part of the experiment, we highlight how each voltammetric parameter affects the signal-to-noise ratio and the resolution of the voltammetric response of hydroquinone, taken as an example of the application of this electrochemical technique. A Design of Experiment is then applied to optimize the intensity and the sharpness of the oxidation peak response. Finally, an analogous approach is followed to optimize the peak resolution of an equimolar hydroquinone and catechol mixture to achieve the best separation among the peak current response for the two electrochemical processes. Thanks to these two experiments, the student will identify the correct choice of parameters to optimize as key factors for achieving the best analytical performance in specific applications.