Sensitive electrochemical detection of ozone

An amperometric sensor capable of detecting ozone in the low ppb range was developed. The most suitable electrochemical cell was based on a gold-Nafion electrode with 0.5 M H 2SO 4 as internal electrolyte solution. It is demonstrated, that by careful selection of the experimental conditions such as electrode materials, electrolyte solution and applied potential the determination of low concentrations of ozone in air is possible with detection limits of 0.6 ppb. Cross-sensitivities to the major inorganic gaseous species found in the atmosphere, are also presented, and the use of a chemical filter to circumvent the interference by nitrogen dioxide is described.