Determination of Ammonium Ion Employing an Electronic Tongue Based on Potentiometric Sensors

Abstract

A method for determining ammonium ion concentration from complex aqueous samples is presented in this work. It does not need to eliminate chemical interferences, mainly sodium and potassium, because an array of potentiometric sensors with intrinsic responses is used. The measurements taken from the array are processed with a multicomponent data treatment. This approach is already known as electronic tongue. Multivariable calibration was implemented with an artificial neural network, trained under the rules of the Bayesian regularization. The developed system has been applied to water samples from rivers and wastewaters with ammonium content in the range 1 × 10⁻⁴–5 × 10⁻² mol L⁻¹. Results are similar to those obtained with other reference methods.

Keywords:

• Electronic tongue
• Sensor array
• Bayesian regularization
• Neural networks
• Ion selective electrode array

Acknowledgment

This work is supported by Spanish Ministry of Science and Technology, MCyT (Madrid), (Project PPQ2001–1950) and by the Department of Universities, Research and Society of Information (DURSI) from Generalitat de Catalunya. Mobility of researchers was provided by an AIRE(DURSI) grant.