A six sensor array of coated wire electrodes for use in a portable flow injection analyzer

An array of five photo-cured epoxydiacrylate membrane based coated-wire electrodes and a Ag/AgCl wire electrode used as a chloride sensor were all used simultaneously in a previously reported multielectrode flow cell and in a portable flow injection analyzer [1]. Photo-cured coated-wire electrodes for ammonium, calcium, hydrogen (pH), nitrate and potassium and Ag/AgCl wire based chloride electrode were developed for remote-site monitoring. The photo-cured membranes prepared exhibited strong adhesion to the metal substrate and showed improved mechanical strength compared to poly(vinyl chloride) based membranes. Each sensor in the present electrode-array exhibited near-Nernstian response over a log-linear range of between 0.1 mM and 10 mM with detection limits of 0.01 mM in the flow injection potentiometric mode. The flow injection cell was capable of determining the respective ions in various water samples and the results were in good agreement with comparative analytical methods.