Characterization of Organic Solvents for Electrochemical Air Pollution Sensors

The method of measuring small concentrations of pollutant gases utilizing sealed electrochemical sensors has many advantages over the conventional methods. The development of specific electrochemical sensors for the detection of sulfur dioxide and oxides of nitrogen at temperatures to 80°C warranted further research into improved organic electrolyte systems. A useful technique for evaluating a number of electrolyte systems is the sweep voltammetric characterization. Dissolved pollutant gases are activated and electrooxidized or electroreduced by changing the potential on a sensing electrode. The data can be rapidly collected and are adequate to give information pertaining to reaction potentials and the resultant current, possible interfering gases, and electrolyte stability. Tests of assembled pollution sensors utilizing electrolytes selected by sweep voltammetric techniques have verified the usefulness of the method.