“Electronic tongue” integrated sensor system based on an array of ion-selective field-effect transistors for multicomponent analysis of liquid media

Results obtained with an “electronic tongue” device based on an array of ion-selective field transistors integrated into a flow-injection system are presented. The component concentrations in mineral waters from Spanish manufacturers are analyzed. Processing of analytical signals by the partial least squares method improves the accuracy of component determination in mineral waters of close compositions. A single chip integrates sensors sensitive to pH, K+, Na+, Ca2+, and Cl− ions. Mineral waters are classified and the concentrations of the main components are calculated with an error not exceeding 10%.