Evaluation of measuring range and interferences for gas-sensing potentiometric probes

The experimental limit of detection and the interferences for any assembled gas sensor are the analytical features of greatest interest. Theoretical and practical studies of CO₂ and SO₂ gas sensors are reported. In the measurement of CO₂, the sample should not be buffered at too acidic a value, although the rate of diffusion at e.g. pH 6.8, may be slower than at low pH. Choice of sample pH can also be used to limit interfering effects. The conditions must be selected on the basis of the required rate of analysis and the selectivity attainable.