TY  - JOUR
A1  - Horner, G.
A1  - Lau, Steffen
A1  - Kantor, Z.
A1  - Löhmannsröben, Hans-Gerd
T1  - Isotope selective analysis of CO2 with tunable diode laser (TDL) spectroscopy in the NIR
N2  - The performance of a home-built tunable diode laser (TDL) spectrometer, aimed at multi-line detection of carbon dioxide, has been evaluated and optimized. In the regime of the (3001)(III) <-- (000) band of (CO2)-C-12 around 1.6 mum, the dominating isotope species (CO2)-C-12, (CO2)-C-13, and (COO)-C-12-O-18-O-16 were detected simultaneously without interference by water vapor. Detection limits in the range of few ppmv were obtained for each species utilizing wavelength modulation (WM) spectroscopy with balanced detection in a long-path absorption cell set-up. High sensitivity in conjunction with high precision-typically +/-1% and +/-6% for 3% and 0.7% of CO2, respectively-renders this experimental approach a promising analytical concept for isotope-ratio determination of carbon dioxide in soil and breath gas. For a moderate (CO2)-C-12 line, the pressure dependence of the line profile was characterized in detail, to account for pressure effects on sensitive measurements
Y1  - 2004
SN  - 0003-2654
ER  -