Measuring delta13C of atmospheric air with non-dispersive infrared spectroscopy.
The potential use of non-dispersive infrared spectroscopy for measuring delta(13)C in air is demonstrated. This technique has already been successfully established for breath test analyses in medical diagnostics, where the CO(2) concentration ranges from 1 to 5 vol.% in the exhaled breath of vertebrates. For breath tests, the sensitivity and accuracy has been improved to reach a standard deviation of 0.2 per thousand (delta-value). Further adjustments were necessary to improve the sensitivity of the instrument at concentration levels typical of atmospheric air. The long-term stability is given by a standard deviation of 0.35 per thousand for CO(2) concentrations of about 400 ppm with signal averaging over 60 s.
Jäger
Frank
F
Wagner Analysen Technik GmbH, Haferwende 21, 28357, Bremen, Germany. jaeger@wagner-bremen.de
Wagner
Günter
G
Meijer
Harro A J
HA
Kerstel
Erik R T
ER
D000388:Air / Q000032:analysis*; D002245:Carbon Dioxide / Q000032:analysis* / Q000737:chemistry; D002247:Carbon Isotopes / Q000032:analysis*; D013055:Spectrophotometry, Infrared / Q000379:methods*
D002247:Carbon Isotopes; D002245:Carbon Dioxide