A 6 SENSOR ARRAY OF COATED-WIRE ELECTRODES FOR USE IN A PORTABLE FLOW-INJECTION ANALYZER

An array of five photo-cured epoxydiacrylate membrane based coated-wir e electrodes and a Ag/AgCl wire electrode used as a chloride sensor we re ail used simultaneously in a previously reported multielectrode flo w cell and in a portable flow injection analyzer [1]. Photo-cured coat ed-wire electrodes for ammonium, calcium, hydrogen (pH), nitrate and p otassium and Ag/AgCl wire based chloride electrode were developed for remote-site monitoring. The photo-cured membranes prepared exhibited s trong adhesion to the metal substrate and showed improved mechanical s trength 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 o f 0.01 mM in the flow injection potentiometric mode. The flow injectio n cell was capable of determining the respective ions in various water samples and the results were in good agreement with comparative analy tical methods.