A Voltammetric Electronic Tongue for the Resolution of Ternary Nitrophenol Mixtures

Abstract

This work reports the applicability of a voltammetric sensor array able to quantify the content of 2,4-dinitrophenol, 4-nitrophenol, and picric acid in artificial samples using the electronic tongue (ET) principles. The ET is based on cyclic voltammetry signals, obtained from an array of metal disk electrodes and a graphite epoxy composite electrode, compressed using discrete wavelet transform with chemometric tools such as artificial neural networks (ANNs). ANNs were employed to build the quantitative prediction model. In this manner, a set of standards based on a full factorial design, ranging from 0 to 300 mg·L−1, was prepared to build the model; afterward, the model was validated with a completely independent set of standards. The model successfully predicted the concentration of the three considered phenols with a normalized root mean square error of 0.030 and 0.076 for the training and test subsets, respectively, and r ≥ 0.948.

Electronic tongue applications for wastewater and soil analysis

“…90%–110%. Although an important drawback of this approach is the use of mercury electrodes, highly questioned worldwide, similar performance has been demonstrated later with metallic and graphite electrodes in an ET scheme ( González-Calabuig et al., 2018 ).…”

Voltammetric Electronic Tongue Based on Carbon Paste Electrodes Modified with Biochar for Phenolic Compounds Stripping Detection

“…The experimental procedure for phenolic compounds determination was developed in previous optimized experimental and instrumental conditions , according to the following summarized three steps:…”

Voltammetric Electronic Tongues in Food Analysis

“…Unlike human tongues, voltammetric electronic tongues can be used for quantitative purposes if their signals are submitted to a multivariate calibration method such as PLS or ANN. For instance, they can be applied to determine pollutants like nitrophenols [72], heavy metal ions [73] or glyphosate [74] in different samples. In the case of food analysis, predictions can be made not only of the concentrations of relevant species, but also of a large deal of parameters informing about the quality of food products.…”