It would seem, why you need to purify the exhaled air, if it is more useful to purify the air inhaled for health? This is certainly true, but the composition of exhaled air can determine the mass of life-threatening conditions, which will help in the diagnosis of a number of pathologies. Moreover, the greatest danger in this case is precisely the water vapor that “dilutes” the pathological agents and interferes with their registration.
As it is known, some products of vital activity are excreted through the lungs. And, by collecting data on the composition of the exhaled air, one can learn about what is happening in the body. The most obvious example is a banal hangover, when aldehydes are released through the lungs. The composition of air can be analyzed by infrared spectroscopy, but as already indicated, the content of water vapor significantly distorts its results.
According to the Journal of Breath Research, a joint group of scientists from Russia and Germany has created a method for removing these vapors. Their method is based on the difference in the physical properties of gases. The fact is that for each gas there is a point of transition to the liquid phase. Therefore, creating certain conditions, you can separate “one part” of the exhaled air. Given that the composition of atmospheric air is known, and also that it is saturated with water with high partial pressure, it becomes easy to separate it.
The experts created a special cooling condenser that was tested on 5 people aged 35 to 77 years . The collection of a liter of exhaled air takes about 1 minute. And after the procedure, the water content in the exhaled air is reduced by 2500 times. After the application of infrared spectrometry in the exhaled air, in addition to the standard constituents, methane, carbon monoxide, carbon dioxide, acetone, acetic aldehyde and isoprene were discovered, which are usually “masked” with water. In the course of a series of experiments, their content was within the limits of the norm, but in the study of “artificial” air samples saturated with a dangerous content of these substances, IR spectrometry did not detect disturbances in “saturated” air, whereas after “cleaning” the hazardous components were registered no problem.