Ammonia sensor based on propylene carbonate

The electrochemical oxidation of ammonia was studied at room temperature on a platinum black electrode in tetrabutylammonia hexafluorophophate solutions in propylene carbonate solvent. Potentiodynamic experiments and current–time curves at constant potential in a glass cell and a sensor device were performed. From the current–time curves the stationary density current values were obtained, which were proportional to the ammonia concentration in the range necessary for the functioning of the sensor (50–200 ppm). The stability of the sensor and the response to the change of the ammonia concentration were also measured using current–time curves at constant potentials. The functioning of the sensor for gas ammonia in propylene carbonate solvent using Pt black and platinum iridium powder mixture as electrodes was appropriate.An amperometric detection system, which is sensitive to the presence of ammonia, was developed in non-aqueous solutions.