Development of a method to monitor low molecular mass hydrocarbons in exhaled breath of man: preliminary evaluation of its interest for detecting a lipoperoxidation process in vivo.

Low molecular mass hydrocarbons, particularly ethane and pentane, have been measured in expired air of man. The air is collected into 5-10 l polyamide bags. After removal of water vapour and CO2, the hydrocarbons are concentrated on a silicagel column kept at 0 degree C. The column desorption is carried out at 290 degrees C, and the gases are analysed by gas chromatography. A slight but statistically significant increased pentane production was detected in cirrhotic patients.