Automated SIA system using an array of potentiometric sensors for determining alkaline-earth ions in water

This work deals with the simultaneous determination of Mg 2+ , Ca 2+ , and Ba 2+ in water using a PVC-membrane potentiometric sensor array and multivariate calibration, in what is known as electronic tongue. The subsequent processing of the data was based on the use of a multilayer artificial neural network (ANN). The information needed for training or generation of the model was obtained with the aid of an automated analytical system based on the Sequential Injection Analysis (SIA) technique. The modeling ability was verified with an external set of standards, and next the determinations were performed in real samples of mineral waters, where close results for Mg 2+ and Ca 2+ were obtained to those obtained with reference methods. The determination of Ba 2+ can be considered as semi-quantitative for synthetic samples - due to the absence of Ba 2+ in mineral waters, its concentration in real samples was not measured. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.