As ion-selective electrodes based on PVC can be easily fabricated for a set of different ions, they are a popular choice for creation of electronic tongue systems . In such systems, non-specific receptors in the tongue are replaced with chemical sensors, and the generated signal is analysed not by the brain but by a machine learning algorithm. After training the algorithm with a sufficient number of samples (a few dozen to a few hundred), an unknown sample can be tested and assigned to some group (e.g., healthy or cancer patients) through classification or attributed with a certain value through multivariate regression. The first electronic tongue systems were proposed in the 1990's . They can be assembled using different kind of sensors, however potentiometric probes still remain the most used. Electronic tongues have truly amazing capabilities: they can account for very complex background changes from sample to sample, as in fermentation broths , elucidate information that cannot be easily obtained with a single sensor, as in case of differentiation between potable or contaminated water or reduce the impact of interfering species .