Online recording of ethane traces in human breath via infrared laser spectroscopy.
A method is described for rapidly measuring the ethane concentration in exhaled human breath. Ethane is considered a volatile marker for lipid peroxidation. The breath samples are analyzed in real time during single exhalations by means of infrared cavity leak-out spectroscopy. This is an ultrasensitive laser-based method for the analysis of trace gases on the sub-parts per billion level. We demonstrate that this technique is capable of online quantifying of ethane traces in exhaled human breath down to 500 parts per trillion with a time resolution of better than 800 ms. This study includes what we believe to be the first measured expirograms for trace fractions of ethane. The expirograms were recorded after a controlled inhalation exposure to 1 part per million of ethane. The normalized slope of the alveolar plateau was determined, which shows a linear increase over the first breathing cycles and ends in a mean value between 0.21 and 0.39 liter-1. The washout process was observed for a time period of 30 min and was modelled by a threefold exponential decay function, with decay times ranging from 12 to 24, 341 to 481, and 370 to 1770 s. Our analyzer provides a promising noninvasive tool for online monitoring of the oxidative stress status.
von Basum
Golo
G
Institut für Lasermedizin, Universität Düsseldorf, Universitätsstrabetae 1, D-40225 Düsseldorf, Germany.
Dahnke
Hannes
H
Halmer
Daniel
D
Hering
Peter
P
Mürtz
Manfred
M
D000328:Adult; D000465:Algorithms; D001944:Breath Tests / Q000295:instrumentation / Q000379:methods*; D003627:Data Interpretation, Statistical; D004980:Ethane / Q000378:metabolism*; D006801:Humans; D007834:Lasers; D015227:Lipid Peroxidation / Q000502:physiology; D008297:Male; D018384:Oxidative Stress / Q000502:physiology; D011650:Pulmonary Alveoli / Q000378:metabolism; D013055:Spectrophotometry, Infrared
D004980:Ethane