Berlin 2008 – scientific programme

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ST: Fachverband Strahlen- und Medizinphysik

ST 2: Medical Physics: Magnetic Resonance, Ultrasound, Dosimetry

ST 2.4: Talk

Monday, February 25, 2008, 14:00–14:15, H 2033

Non-invasive observation of ¹⁴N¹⁸O in exhaled air — •Christoph Mitscherling, Christof Maul, and Karl-Heinz Gericke — Technische Universität Braunschweig, Institut für Physikalische und Theoretische Chemie, Abteilung Laserchemie, Hans-Sommer-Straße 10, 38106 Braunschweig

Laser-induced fluorescence (LIF) spectroscopy is an extremely sensitive method for the investigation of low nitric oxide (NO) concentrations. LIF enables non-invasive and isotope-selective detection of NO in various biological environments. The excitation of the gamma-band provides fluorescence of A²Σ⁺(v′=0,J′)—→ X²Π_Ω(v″≥ 2,J″) around 247 nm. This method has been used for online detection of exhaled ¹⁴N¹⁶O and ¹⁵N¹⁶O [1].
In a (1+1) resonance enhanced multi-photon ionization (REMPI) time-of-flight mass spectrometer experiment the different NO isotopologues have been investigated separately to find ¹⁴N¹⁸O transitions not interfered with others. These transitions have been investigated further by the LIF device. The combination of LIF and a breath mask provides online exhaled air measurements of ¹⁴N¹⁸O with a maximum time resolution of 20 ms. The detection limit for ¹⁴N¹⁸O is about 6 ppt.

[1] Mitscherling, C. et al.: J. Breath Res. 1 (2007) 026003