Advancing the Sensitivity of Highly Selective Gas Analysis by the Example of Carbon Monoxide Molecules

We present the results of experiments on detection of carbon monoxide (CO molecules) in atmospheric and exhaled air using a microwave spectrometer with sensitivity 1000 times lower than the CO detection threshold in the atmosphere. A modification of the spectrometer by adding a simple and easy-to-use device (preconcentrator) allowed us to increase the sensitivity of gas analysis by 5 orders of magnitude and confidently observe CO in the atmosphere and exhaled air. Combined with a filter performing deep dehumidification of an analyzed air sample without noticeable distortion of the composition of the polar impurity gases, the preconcentrator may be used to increase the sensitivity of many if not all currently known gas analysis methods.