Suitable solid state chemical sensor for HCHO determination

A solid state NiO-polyaniline mixture electrode is proposed and characterised to determine formaldehyde. The influence of ionic strength is particularly significant. The response is slow, so a waiting time, optimised at 90 min is needed, thus preventing a continuous or in-flow condition determination. Some common environmental possible interfering analytes have been tested, the most interfering having been shown to be acetaldehyde that cannot be present at concentration higher than 10-6.