An electronic tongue using potentiometric all-solid-state PVC-membrane sensors for the simultaneous quantification of ammonium and potassium ions in water

Abstract

The simultaneous determination of NH(4)(+) and K(+) in solution has been attempted using a potentiometric sensor array and multivariate calibration. The sensors used are rather non-specific and of all-solid-state type, employing polymeric (PVC) membranes. The subsequent data processing is based on the use of a multilayer artificial neural network (ANN). This approach is given the name "electronic tongue" because it mimics the sense of taste in animals. The sensors incorporate, as recognition elements, neutral carriers belonging to the family of the ionophoric antibiotics. In this work the ANN type is optimized by studying its topology, the training algorithm, and the transfer functions. Also, different pretreatments of the starting data are evaluated. The chosen ANN is formed by 8 input neurons, 20 neurons in the hidden layer and 2 neurons in the output layer. The transfer function selected for the hidden layer was sigmoidal and linear for the output layer. It is also recommended to scale the starting data before training. A correct fit for the test data set is obtained when it is trained with the Bayesian regularization algorithm. The viability for the determination of ammonium and potassium ions in synthetic samples was evaluated; cumulative prediction errors of approximately 1% (relative values) were obtained. These results were comparable with those obtained with a generalized regression ANN as a reference algorithm. In a final application, results close to the expected values were obtained for the two considered ions, with concentrations between 0 and 40 mmol L(-1).

Electronic Tongues Employing Electrochemical Sensors

“…The simplest range from the conventional ISE with internal reference solution [33], or the use of all-solidstate configurations, where the PVC membranes are deposited over a polymeric graphite contact [34], and with the experimental setup shown on the Figure 3. This concept has also been reapplied on miniaturized substrates, derived from Au layered printed circuit board technology, on single devices [35], or integrating several of them in a single piece [36].…”

Can the black box be cracked? The augmentation of microbial ecology by high-resolution, automated sensing technologies

“…The challenge to encompass the tremendous complexity of organic compounds presented to the microbial community, and the potential niches these diverse compounds present, has been partially addressed by the technological advances in electrochemical sensors (Rudnitskaya and Legin, 2008). One example of a versatile electrochemical sensor is the 'electronic tongue' which uses pulsed voltammetry to detect a wide range of redox-active organic and inorganic compounds (Gallardo et al, 2003(Gallardo et al, , 2004 Figure 1 Conceptual model of variables influencing microbial communities in aquatic ecosystems, and general examples of automated sensing technologies (ASTs) available for observing these variables. In-development sensing technologies are given in italics.…”

Use of an Electronic Tongue Based on All‐Solid‐State Potentiometric Sensors for the Quantitation of Alkaline Ions

“…Also, Vlasov used a similar approach to classify food and clinical samples [10], and Krantz-Rülcker one to monitor a mineral water bottling plant [11]. There are few references in this respect, however, to the use of an electronic tongue for quantification purposes; such references include the determination of various species in water and wine [12], or beer and soft drinks [13], and the simultaneous determination of two univalent cations in water without removing interferents [14].…”