Application of Contactless Impedance Detection to Determination of Substances in Gaseous Phase

A simple cell, consisting of two insulated wire electrodes placed in a PTFE tube through which the test gaseous phase flows, has been applied to capacitively coupled contactless conductometric detection (C4D) and determination of water vapour in the air, to examine the possibilities of the use of C4D for analyses of gaseous samples. It has been found that the measurement is sufficiently sensitive and reliable for determinations of common concentrations of water in the air. The dynamic characteristics and the signal stability demonstrate that the cell will be suitable for long‐term continuous monitoring of the air humidity. Qualitative tests indicate that vapours of organic solvents can also be monitored. To the authors knowledge, this is the first attempt to use C4D in gas analyses.