scholarly journals Comparison of nitrous acid detection using open-path incoherent broadband cavity-enhanced absorption spectroscopy and extractive long-path absorption photometry

2021 ◽  
Author(s):  
Sophie Dixneuf ◽  
Albert A. Ruth ◽  
Rolf Häseler ◽  
Theo Brauers ◽  
Franz Rohrer ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Nitrous Acid ◽  
Hot Spot ◽  
Integration Time ◽  
Mixing Ratios ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy ◽  
Open Path ◽  
Ccd Detector ◽  
No2 Detection

Abstract. An instrument based on 20 m open-path incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) was established at the Jülich SAPHIR chamber in Spring 2011. The setup was optimized for the detection of HONO and NO2 in the near UV region 352–386 nm, utilizing a bright hot-spot Xe-arc lamp and a UV-enhanced CCD detector. A 2σ detection limit of 26 pptv for HONO and 76 pptv for NO2 was achieved for an integration time of 1 min. Methacrolein has also been detected at mixing ratios below 5 ppbv. The IBBCEAS instrument’s performance for HONO and NO2 detection was compared to that of extractive wet techniques, long-path absorption photometry (LOPAP) and chemiluminescence spectrometry (CLS) NOx detection, respectively.

scholarly journals Night-time chemistry above London: measurements of NO<sub>3</sub> and N<sub>2</sub>O<sub>5</sub> from the BT Tower during REPARTEE-II

2010 ◽  
Vol 10 (6) ◽  
pp. 14347-14386
Author(s):  
A. K. Benton ◽  
J. M. Langridge ◽  
S. M. Ball ◽  
W. J. Bloss ◽  
M. Dall'Osto ◽  
...  
Keyword(s):  
Nitrogen Oxides ◽  
Absorption Spectroscopy ◽  
Nitrogen Compounds ◽  
Equilibrium Partitioning ◽  
Night Time ◽  
Positive Correlation ◽  
Mixing Ratios ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy ◽  
The Mean

Abstract. Broadband cavity enhanced absorption spectroscopy (BBCEAS) has been used to measure the sum of concentrations of NO3 and N2O5 from the BT (telecommunications) Tower 160 m above street level in central London during the REPARTEE II campaign in October and November 2007. Substantial variability was observed in these night-time nitrogen compounds: peak NO3+N2O5 mixing ratios reached 800 pptv, whereas the mean night-time NO3+N2O5 was approximately 30 pptv. Additionally, [NO3+N2O5] showed negative correlations with [NO] and [NO2] and a positive correlation with [O3]. Co-measurements of temperature and NO2 from the BT Tower were used to calculate the equilibrium partitioning between NO3 and N2O5 which was always found to strongly favour N2O5 (NO3/N2O5=0.01 to 0.04). Two methods are used to calculate the lifetimes for NO3 and N2O5, the results being compared and discussed in terms of the implications for the night-time oxidation of nitrogen oxides and the night-time sinks for NOy.

Monitoring Ambient Nitrate Radical by Open Path Cavity Enhanced Absorption Spectroscopy

2020 ◽  
Author(s):  
Haichao Wang ◽  
Keding Lu
Keyword(s):  
Absorption Spectroscopy ◽  
Field Application ◽  
Nitrate Radical ◽  
Absorption Length ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy ◽  
Open Path ◽  
Sampling Line ◽  
Forest Region ◽  
Reactive Trace Gases

&lt;p&gt;We described an open-path cavity enhanced absorption spectroscopy (OP-CEAS) technique for ambient measurement of nitrate radical (NO&lt;sub&gt;3&lt;/sub&gt;) near 662 nm. Compared with the close type CEAS system with a sampling line, the OP-CEAS is featured with high accuracy due to free of quantifying NO&lt;sub&gt;3 &lt;/sub&gt;loss in the sampling line and cavity. Based on a 0.84 m long open path cavity, the effective absorption length of ~5 kilometers is achieved by a coupled high reflectivity mirrors with the reflectivity of 0.99985 at 662 nm. The detection limit of OP-CEAS for NO&lt;sub&gt;3&lt;/sub&gt; measurement is 3.0 pptv (2&amp;#963;) in 30 seconds. The uncertainty is 11.2% and dominated by the cross section of NO&lt;sub&gt;3&lt;/sub&gt;. The instrument was successfully applied in a field measurement at low particulate matter (PM) loading condition. As the sensitive would be decreased due to the strong PM extinctions under heavy PM pollution condition, we highlight the feasibility of this OP-CEAS configuration in the field application under the low PM condition, such as the forest region affected by anthropogenic emissions. This technique also appropriates to be expended in the field detection of other reactive trace gases in future studies.&lt;/p&gt;

scholarly journals Implementation of an incoherent broadband cavity-enhanced absorption spectroscopy technique in an atmospheric simulation chamber for in situ NO<sub>3</sub> monitoring: characterization and validation for kinetic studies

2020 ◽  
Vol 13 (11) ◽  
pp. 6311-6323 ◽  
Author(s):  
Axel Fouqueau ◽  
Manuela Cirtog ◽  
Mathieu Cazaunau ◽  
Edouard Pangui ◽  
Pascal Zapf ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Rate Constants ◽  
Optical Cavity ◽  
In Situ Monitoring ◽  
Effective Length ◽  
Integration Time ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy ◽  
Simulation Chamber

Abstract. An incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) technique has been developed for the in situ monitoring of NO3 radicals at the parts per trillion level in the CSA simulation chamber (at LISA). The technique couples an incoherent broadband light source centered at 662 nm with a high-finesse optical cavity made of two highly reflecting mirrors. The optical cavity which has an effective length of 82 cm allows for up to 3 km of effective absorption and a high sensitivity for NO3 detection (up to 6 ppt for an integration time of 10 s). This technique also allows for NO2 monitoring (up to 9 ppb for an integration time of 10 s). Here, we present the experimental setup as well as tests for its characterization and validation. The validation tests include an intercomparison with another independent technique (Fourier-transform infrared, FTIR) and the absolute rate determination for the reaction trans-2-butene + NO3, which is already well documented in the literature. The value of (4.13 ± 0.45) × 10−13 cm3 molecule−1 s−1 has been found, which is in good agreement with previous determinations. From these experiments, optimal operation conditions are proposed. The technique is now fully operational and can be used to determine rate constants for fast reactions involving complex volatile organic compounds (VOCs; with rate constants up to 10−10 cm3 molecule−1 s−1).

Development of an incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) instrument for autonomous field measurements of HONO and NO2 in a rural area

2021 ◽  
Author(s):  
Lingshuo Meng ◽  
Gaoxuan Wang ◽  
Cécile Coeur ◽  
Alexandre Tomas ◽  
Tao Wu ◽  
...  
Keyword(s):  
Rural Area ◽  
Absorption Spectroscopy ◽  
Atmospheric Chemistry ◽  
Nitrous Acid ◽  
Trace Gases ◽  
Ambient Air ◽  
Rural Site ◽  
Oh Radicals ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy

&lt;p&gt;Nitrous acid (HONO) is one of the important atmospheric trace gases due to its contribution to the cycles of nitrogen oxides (NOx) and hydrogen oxides (HOx). In particular it acts as a precursor of tropospheric OH radicals, which is responsible for the self-cleansing capacity of the atmosphere [1,2]. We developed an instrument based on incoherent broadband cavity enhanced absorption spectroscopy (IBBCEAS) for automatic measurement of HONO in a rural area in a summer period during a field &quot;Campagne d&amp;#8217;OBservation Intensive des Ae&amp;#769;rosols et pre&amp;#769;curseurs a&amp;#768; Caillou&amp;#235;l-Cr&amp;#233;pigny (COBIACC)&quot; in France. IBBCEAS technique is now extensively used in field applications for the measurements of both trace gases and aerosols [3,4].&lt;/p&gt;&lt;p&gt;Real-time in situ measurements of HONO and NO&lt;sub&gt;2&lt;/sub&gt; have been simultaneously carried out. The IBBCEAS instrument performance has been demonstrated and validated through lab-based tests, and in particular through field intercomparison via side-by-side measurements of temporal concentration profiles of HONO and NO&lt;sub&gt;2&lt;/sub&gt; in the rural area. The intercomparison of the concentration measurements between IBBCEAS and an instrument called MARGA (Monitor for AeRosols and Gases in Ambient air) for HONO, and IBBCEAS vs. a reference NOx analyzer for NO&lt;sub&gt;2&lt;/sub&gt;. Good agreements have been observed which demonstrated the performance of the developed IBBCEAS instrument for the measurement of atmospheric HONO concentration (&lt;5 ppb) in a rural area.&lt;/p&gt;&lt;p&gt;The preliminary experimental results will be presented and discussed.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Acknowledgments&lt;/strong&gt; This work was supported by the CPER CLIMIBIO program and the Labex CaPPA project (ANR-10-LABX005). The authors highly appreciate the offers of Mr. Eric Wetzels from Polyfluor Plastics bv for the help in our instrumental conception involving Teflon pipe.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;References&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;[1] X. Li, T. Brauers, R. H&amp;#228;seler, R. Bohn, H. Fuchs, A. Hofzumahaus, F. Holland, S. Lou, et al., Exploring the atmospheric chemistry of nitrous acid (HONO) at a rural site in Southern China, Atmos. Chem. Phys. &lt;strong&gt;12&lt;/strong&gt; (2012) 1497-1513.&lt;/p&gt;&lt;p&gt;[2] H. Su, Y. Cheng, M. Shao, D. Gao, Z. Yu, L. Zeng, J. Slanina, et al., Nitrous acid (HONO) and its daytime sources at a rural site during the 2004 PRIDE&amp;#8208;PRD experiment in China, J. Geophys. Res. &lt;strong&gt;113&lt;/strong&gt; (2008) D14312.&lt;/p&gt;&lt;p&gt;[3] T. Wu, Q. Zha, W. Chen, Z. Xu, T. Wang, X. He, Development and deployment of a cavity enhanced UV-LED spectrometer for measurements of atmospheric HONO and NO&lt;sub&gt;2&lt;/sub&gt; in Hong Kong, Atmos. Environ. &lt;strong&gt;95&lt;/strong&gt; (2014) 544-551.&lt;/p&gt;&lt;p&gt;[4] L. Meng, G. Wang, P. Augustin, M. Fourmentin, Q. Gou, E. Fertein, T. N. Ba, C. Coeur, A. Tomas, W. Chen, Incoherent broadband cavity enhanced absorption spectroscopy-based strategy for direct measurement of aerosol extinction in lidar blind zone, Opt. Lett. &lt;strong&gt;45 &lt;/strong&gt;(2020) 1611-1614.&lt;/p&gt;

scholarly journals Simultaneous detection of C<sub>2</sub>H<sub>6</sub>, CH<sub>4</sub>, and <i>δ</i><sup>13</sup>C-CH<sub>4</sub> using optical feedback cavity-enhanced absorption spectroscopy in the mid-infrared region: towards application for dissolved gas measurements

2019 ◽  
Vol 12 (6) ◽  
pp. 3101-3109 ◽  
Author(s):  
Loic Lechevallier ◽  
Roberto Grilli ◽  
Erik Kerstel ◽  
Daniele Romanini ◽  
Jérôme Chappellaz
Keyword(s):  
Absorption Spectroscopy ◽  
Optical Feedback ◽  
Optical Cavity ◽  
Simultaneous Detection ◽  
Infrared Region ◽  
Integration Time ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy ◽  
Interband Cascade Laser ◽  
Gas Measurements

Abstract. Simultaneous measurement of C2H6 and CH4 concentrations, and of the δ13C-CH4 isotope ratio is demonstrated using a cavity-enhanced absorption spectroscopy technique in the mid-IR region. The spectrometer is compact and has been designed for field operation. It relies on optical-feedback-assisted injection of 3.3 µm radiation from an interband cascade laser (ICL) into a V-shaped high-finesse optical cavity. A minimum absorption coefficient of 2.8×10-9 cm−1 is obtained in a single scan (0.1 s) over 0.7 cm−1. Precisions of 3 ppbv, 11 ppbv, and 0.08 ‰ for C2H6, CH4, and δ13C-CH4, respectively, are achieved after 400 s of integration time. Laboratory calibrations and tests of performance are reported here. They show the potential for the spectrometer to be embedded in a sensor probe for in situ measurements in ocean waters, which could have important applications for the understanding of the source and fate of hydrocarbons from the seabed and in the water column.

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