A new approach in voltammetric profiling of wines and whiskies based on a useful faradaic signal component
In this work, we have demonstrated that voltammetric signals obtained using metallic electrodes in a simple supporting electrolyte constitute an adequate tool for distinguishing samples of various characteristics. We have shown that successful profiling could be achieved if only the faradaic component of the DPV signal is used, disregarding the capacitive charging current of the double layer. New environmentally friendly voltammetric sensors were used, i.e. an iridium quadruple-disk electrode (q-DIrE) and, for comparison, a platinum disk electrode (PtDE). Profiling was carried out for wine and Scotch whisky samples. The alternating trilinear decomposition (ATLD) algorithm was used for decomposition of the total current recorded using the DPV technique. Perfect distinction and repeatability of the considered objects (wine and whisky samples) in the principal component space were obtained. It can be concluded that rejection of the disturbing and non-informative capacitive current gives an optimal effect in profiling. The described approach can be used in routine food analysis. The strategy based on the faradaic current was proposed for the first time and it extends the application of voltammetry in the assessment of the originality and authenticity of samples.