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Titel |
13CO2/12CO2 isotope ratio analysis in human breath using a 2 μm diode laser |
VerfasserIn |
Mingguo Sun, Zhensong Cao, Kun Liu, Guishi Wang, Tu Tan, Xiaoming Gao, Weidong Chen, Huang Yinbo, Rao Ruizhong |
Konferenz |
EGU General Assembly 2015
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 17 (2015) |
Datensatznummer |
250104240
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Publikation (Nr.) |
EGU/EGU2015-3662.pdf |
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Zusammenfassung |
The bacterium H. pylori is believed to cause peptic ulcer. H. pylori infection in the human
stomach can be diagnosed through a CO2 isotope ratio measure in exhaled breath. A laser
spectrometer based on a distributed-feedback semiconductor diode laser at 2 μm is developed
to measure the changes of 13CO2/12CO2 isotope ratio in exhaled breath sample with the CO2
concentration of ~4%. It is characterized by a simplified optical layout, in which a single
detector and associated electronics are used to probe CO2 spectrum. A new type
multi-passes cell with 12 cm long base length , 29 m optical path length in total
and 280 cm3 volume is used in this work. The temperature and pressure are well
controlled at 301.15 K and 6.66 kPa with fluctuation amplitude of 25 mK and 6.7
Pa, respectively. The best 13δ precision of 0.06owas achieved by using wavelet
denoising and Kalman filter. The application of denoising and Kalman filter not
only improved the signal to noise ratio, but also shorten the system response time. |
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