Incoherent broad-band cavity-enhanced absorption spectroscopy for simultaneous trace measurements of NO2 and NO3 with a LED source
Incoherent broad-band cavity-enhanced absorption spectroscopy for simultaneous trace measurements of NO2 and NO3 with a LED source
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DOI：
10.1007/s00340-010-4253-x
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发表时间：
2010-10
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通讯作者：
Irene Ventrillard-Courtillot;Ella Sciamma O’Brian;S. Kassi;G. Méjean;D. Romanini
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文献类型：
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作者：
Irene Ventrillard-Courtillot;Ella Sciamma O’Brian;S. Kassi;G. Méjean;D. Romanini
在过去的十年中，由于人们对空气质量和空气污染控制的重要性的认识不断提高，已经开发了许多诊断工具和技术来检测和量化污染物的浓度，如NOx，SOx，CO和CO2。我们在这里提出了一个非相干宽带腔增强光谱（IBB-CEAS）的设置，它使用一个发光二极管发射约625 nm的NO2和NO3的同时检测。通过填充有气体样品的高精细光学腔传输的LED光由低分辨率光谱仪检测。在用NO2参考样品校准光谱仪后，吸收光谱的线性多组分拟合分析允许同时测量环境空气流中的NO2和NO3浓度。最佳平均时间被发现是在400秒的顺序，似乎是有限的光谱仪的漂移。在此平均时间，最小可检测吸收为2×10− 10 cm −1，相当于NO2的检测限为600 pptv，NO3的检测限为2 pptv。这种紧凑型和低成本的仪器是一个有前途的诊断工具，在城市环境中的空气质量控制。
In the past decade, due to a growing awareness of the importance of air quality and air pollution control, many diagnostic tools and techniques have been developed to detect and quantify the concentration of pollutants such as NOx, SOx, CO, and CO2. We present here an Incoherent Broad-Band Cavity-Enhanced Spectroscopy (IBB-CEAS) set-up which uses a LED emitting around 625 nm for the simultaneous detection of NO2and NO3. The LED light transmitted through a high-finesse optical cavity filled with a gas sample is detected by a low resolution spectrometer. After calibration of the spectrometer with a NO2reference sample, a linear multicomponent fit analysis of the absorption spectra allows for simultaneous measurements of NO2and NO3concentrations in a flow of ambient air. The optimal averaging time is found to be on the order of 400 s and appears to be limited by the drift of the spectrometer. At this averaging time the smallest detectable absorption is 2×10−10cm−1, which corresponds to detection limits of 600 pptv for NO2and 2 pptv for NO3. This compact and low cost instrument is a promising diagnostic tool for air quality control in urban environments.