Electronic tongues for environmental monitoring based on sensor arrays and pattern recognition: a review

The use of sensor arrays and pattern recognition applied to the obtained signal patterns for environmental monitoring are discussed in some detail. Different types of electronic tongues are described and evaluated for monitoring purposes. More specifically the performance of multielectrode arrays used for voltammetric analysis of aqueous samples is described. It is, e.g. shown how such an `electronic tongueʹ can be used to monitor the quality of water in a production plant for drinking water. It is pointed out that the concepts of `electronic nosesʹ and `electronic tonguesʹ often predict a quality of a sample rather than giving exact information about concentrations of individual species.