A Novel Method Based on Voltammetry for the Qualitative Analysis of Water

This paper deals with the use of voltammetric techniques for the qualitative analysis of water, where we focus on the signal analysis approach and its evaluation in terms of discrimination capability. The prototype described in this paper and the signal analysis chain has been designed in the framework of the development of a field instrument for classification and change detection purposes. The common concept in the various approaches presented in the literature lies in the combination of poorly selective sensors for the characterization of liquids. The fundamental idea of this paper is to investigate how an adequate signal processing approach applied to a mature and affordable sensor technique (voltammetry) can address the issue of extracting aggregate chemical information, which is useful to characterize the liquid under measurement. In the proposed approach, dimensionality reduction is performed in a transformed domain via discrete cosine transform with an appropriate selection of a low-dimensionality subset of the transformed coefficients. The novel methodological approach to the signal processing, two application experiments, and the test set that has been built for the experiments are described here. Finally, the capability of discriminating between different kinds of water is discussed.