Bailey D Michelle, Zhao Gang, Fleisher Adam J
Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States.
Anal Chem. 2020 Oct 20;92(20):13759-13766. doi: 10.1021/acs.analchem.0c01868. Epub 2020 Oct 1.
As a potent greenhouse gas and an ozone-depleting agent, nitrous oxide (NO) plays a critical role in the global climate. Effective mitigation relies on understanding global sources and sinks, which can be supported through isotopic analysis. We present a cross-dispersed spectrometer, coupled with a mid-infrared frequency comb, capable of simultaneously monitoring all singly substituted, stable isotopic variants of NO. Rigorous evaluation of the instrument lineshape function and data treatment using a Doppler-broadened, low-pressure gas sample are discussed. Laboratory characterization of the spectrometer demonstrates sub-GHz spectral resolution and an average precision of 6.7 × 10 for fractional isotopic abundance retrievals in 1 s.
作为一种强效温室气体和臭氧消耗剂，一氧化二氮（N₂O）在全球气候中起着关键作用。有效的减排措施依赖于对全球源和汇的了解，而同位素分析可以为此提供支持。我们展示了一种与中红外频率梳耦合的交叉色散光谱仪，它能够同时监测N₂O的所有单取代稳定同位素变体。文中讨论了使用多普勒加宽的低压气体样品对仪器线形函数和数据处理进行的严格评估。该光谱仪的实验室表征显示其具有亚吉赫兹的光谱分辨率，并且在1秒内对同位素丰度分数检索的平均精度为6.7×10⁻⁶。
