利用近红外可调谐二极管激光（TDL）光谱技术对二氧化碳进行同位素选择性分析。

Isotope selective analysis of CO(2) with tunable diode laser (TDL) spectroscopy in the NIR.

作者信息

Horner Gerald, Lau Steffen, Kantor Zoltan, Lohmannsroben Hans-Gerd

机构信息

Institute of Chemistry, Physical Chemistry, Potsdam University, Karl-Liebknecht Str. 24-25, D-14476 Potsdam-Golm, Germany.

出版信息

Analyst. 2004 Aug;129(8):772-8. doi: 10.1039/b404552c. Epub 2004 Jul 6.

DOI:10.1039/b404552c

PMID:15284924

Abstract

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(0)1)(III) <-- (000) band of (12)CO(2) around 1.6 microm, the dominating isotope species (12)CO(2), (13)CO(2), and (12)C(18)O(16)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 (per thousand) and +/-6 (per thousand) for 3% and 0.7% of CO(2), respectively -- renders this experimental approach a promising analytical concept for isotope-ratio determination of carbon dioxide in soil and breath gas. For a moderate (12)CO(2) line, the pressure dependence of the line profile was characterized in detail, to account for pressure effects on sensitive measurements.

摘要

针对二氧化碳多谱线检测的一台自制可调谐二极管激光（TDL）光谱仪的性能已得到评估和优化。在1.6微米附近（12）CO₂的（30(0)1）（III）←（000）波段范围内，主要的同位素种类（12）CO₂、（13）CO₂和（12）C（18）O（16）O被同时检测到，且不受水蒸气干扰。在长程吸收池装置中利用带平衡检测的波长调制（WM）光谱法，每种物质的检测限达到了几个百万分比体积（ppmv）。高灵敏度与高精度相结合——对于3%和0.7%的CO₂，典型精度分别为±1（千分之一）和±6（千分之一）——使得这种实验方法成为一种用于测定土壤和呼出气体中二氧化碳同位素比率的有前景的分析概念。对于一条中等强度的（12）CO₂谱线，详细表征了谱线轮廓的压力依赖性，以考虑压力对灵敏测量的影响。