Isotope selective analysis of CO2 with tunable diode laser (TDL) spectroscopy in the NIR
- 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 (30<SUP>0</SUP>1)<SUB>III</SUB> / (000) band of <SUP>12</SUP>CO<SUB>2</SUB> around 1.6 μm, the dominating isotope species <SUP>12</SUP>CO<SUB>2</SUB>, <SUP>13</SUP>CO<SUB>2</SUB>, and <SUP>12</SUP>C<SUP>18</SUP>O<SUP>16</SUP>O 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 CO<SUB>2</SUB>, respectively— renders this experimental approach a promising analytical concept for isotope-ratio determination of carbon dioxide in soil and breath gas. For a moderate <SUP>12</SUP>CO<SUB>2</SUB> line, the pressure dependence of the line profile was characterized in detail, toThe 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 (30<SUP>0</SUP>1)<SUB>III</SUB> / (000) band of <SUP>12</SUP>CO<SUB>2</SUB> around 1.6 μm, the dominating isotope species <SUP>12</SUP>CO<SUB>2</SUB>, <SUP>13</SUP>CO<SUB>2</SUB>, and <SUP>12</SUP>C<SUP>18</SUP>O<SUP>16</SUP>O 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 CO<SUB>2</SUB>, respectively— renders this experimental approach a promising analytical concept for isotope-ratio determination of carbon dioxide in soil and breath gas. For a moderate <SUP>12</SUP>CO<SUB>2</SUB> line, the pressure dependence of the line profile was characterized in detail, to account for pressure effects on sensitive measurements.…
Author details: | Gerald Hörner, Steffen Lau, Zoltan Kantor, Hans-Gerd LöhmannsröbenORCiDGND |
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URN: | urn:nbn:de:kobv:517-opus-10167 |
Publication series (Volume number): | Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe (paper 020) |
Publication type: | Postprint |
Language: | English |
Publication year: | 2004 |
Publishing institution: | Universität Potsdam |
Release date: | 2006/11/01 |
Tag: | Diodenlaserspektroskopie Isotope ratio; carbon monoxide; diode laser spectroscopy |
GND Keyword: | Isotopenverhältnis; Kohlendioxid |
Source: | Hörner et al. Analyst Vol.129, No. 8; 772-778 (2004) |
RVK - Regensburg classification: | VE 9908 |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
External remark: | This paper was published in: The Analyst, 129 (2004), pp. 772-778 ISSN: 0003-2654 DOI:10.1117/10.1039/b404552c Reproduced by permission of The Royal Society of Chemistry. This document may not be further made available or distributed. |