Simultaneous Quantification of Nine Major Water-Soluble Inorganic Ions Using a Potentiometric Electronic Tongue in Cheese Samples

Combining an Integrated Sensor Array with Machine Learning for the Simultaneous Quantification of Multiple Cations in Aqueous Mixtures

“…OED results in a dramatic reduction of the number of required concentration combinations to describe the interaction of multiple analytes with different concentration values. 27,28 Six factors (analytes) with five possible levels (concentrations) define an orthogonal array of 25 (L 25 = 5 6 ) testing mixtures, compared to the prohibitively large number of tests for all possible combinations of six ions with five different concentrations (5 6 = 15,625 solutions). All 25 mixtures defined by the OED are identified as separable clusters after PCA (Figure 7), suggesting that the sensor array can resolve mixtures of the selected analytes and concentration variations.…”

“…Quantitative analysis in complex solutions comprising multiple analytes and multiple, possibly unknown, interferents is not feasible based on idealized models, such as the Nikolskii–Eisenman equation, and instead requires extensive multivariate calibration procedures. Potentiometric electronic tongues have been demonstrated to be potentially useful for the characterization of a range of different liquids (e.g., water, wine, milk, and juice) and for the direct quantification of various analytes (e.g., cations, anions, organic acids, and peroxides), enlarging their fields of application. − Electronic tongues for quantification of ionic analytes are mainly composed of multiple potentiometric − or voltammetric sensors, but the integration of colorimetric sensors has also been reported . Potentiometric electronic tongues were demonstrated to be attractive for in situ applications and monitoring changes in liquid composition over time due to their facile miniaturization and the possibility to design portable devices for remote sensing .…”

Analysis of Milk Using a Portable Potentiometric Electronic Tongue Based on Five Polymeric Membrane Sensors

“…These works use partial least squares (PLS) models to establish correlations between the signals obtained with the sensor arrays and the chemical parameters obtained by classical techniques. For example, e-tongues have been used to determine the content of ethanol, acetaldehyde, lactic acid, acetic acid, and citric acid in probiotic fermented milk ( Hruskar et al, 2010 ), or for the simultaneous detection of water-soluble ions ( Torabi et al, 2020 ).…”

“…In many cases, potentiometric e-tongues consist of a large number of sensors (typically between 8 and 36) ( Dias et al, 2009 ; Podrażka et al, 2018 ; Torabi et al, 2020 ). The idea behind these large arrays is that a higher number of sensing units with different selectivity and sensitivity can provide a larger amount of information, improving the discrimination and prediction capability of the e-tongue.…”