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Suhail K, George M, Chandran S, Varma R, Venables DS, Wang M, Chen J. Open path incoherent broadband cavity-enhanced measurements of NO 3 radical and aerosol extinction in the North China Plain. Spectrochim Acta A Mol Biomol Spectrosc 2019; 208:24-31. [PMID: 30286400 DOI: 10.1016/j.saa.2018.09.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/31/2018] [Accepted: 09/11/2018] [Indexed: 06/08/2023]
Abstract
We describe the observation of the NO3 radical using an incoherent broadband cavity-enhanced absorption spectrometer in an open-path configuration (OP-IBBCEAS) in a polluted summer environment in continental China. The instrument was installed 17 m above the ground at the top of a residential complex near the CAREBeijing-NCP 2014 site in Wangdu, Hebei province, about 200 km southwest of Beijing over the period 28 to 30 June 2014. The separation between the transmitter and receiver components of the instrument was 335 cm and the effective pathlength in clean reference air was ~3.4 km. NO3 was detected above the detection limit on all three nights when the instrument was operational. The maximum mixing ratio measured was ~175 pptv with a detection sensitivity of ~36 pptv for measurements with an average acquisition time of 10 min. While most extractive instruments try to avoid interferences arising from aerosol extinction, the open path configuration has advantages owing to its ability to detect trace gases even in the presence of aerosol loading. Moreover, concurrent retrieval of aerosol optical extinction is possible from analysis of the absorption magnitude of the oxygen B-band at 687 nm. The experimental setup, its calibration, data acquisition, and analysis procedure are discussed, and the results presented here demonstrate the sensitivity and specificity that can be achieved at high spatial and temporal resolution using the novel configuration of IBBCEAS in the open path.
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Affiliation(s)
- K Suhail
- School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, China; Department of Physics, National Institute of Technology Calicut, Calicut 673601, Kerala, India
| | - M George
- Department of Physics, National Institute of Technology Calicut, Calicut 673601, Kerala, India
| | - S Chandran
- Department of Physics, National Institute of Technology Calicut, Calicut 673601, Kerala, India; Physics Department & Environmental Research Institute, University College Cork, Cork, Ireland; Optind Solutions Pvt. LTD. Unit 11, Technology Business Incubator, National Institute of Technology Calicut, Calicut 673601, Kerala, India
| | - R Varma
- Department of Physics, National Institute of Technology Calicut, Calicut 673601, Kerala, India
| | - D S Venables
- School of Chemistry & Environmental Research Institute, University College Cork, Cork, Ireland
| | - M Wang
- School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - J Chen
- School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, China.
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Sun J, Ding J, Liu N, Yang G, Li J. Detection of multiple chemicals based on external cavity quantum cascade laser spectroscopy. Spectrochim Acta A Mol Biomol Spectrosc 2018; 191:532-538. [PMID: 29096120 DOI: 10.1016/j.saa.2017.10.059] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 10/06/2017] [Accepted: 10/24/2017] [Indexed: 06/07/2023]
Abstract
A laser spectroscopy system based on a broadband tunable external cavity quantum cascade laser (ECQCL) and a mini quartz crystal tuning fork (QCTF) detector was developed for standoff detection of volatile organic compounds (VOCs). The self-established spectral analysis model based on multiple algorithms for quantitative and qualitative analysis of VOC components (i.e. ethanol and acetone) was detailedly investigated in both closed cell and open path configurations. A good agreement was obtained between the experimentally observed spectra and the standard reference spectra. For open path detection of VOCs, the sensor system was demonstrated at a distance of 30m. The preliminary laboratory results show that standoff detection of VOCs at a distance of over 100m is very promising.
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Affiliation(s)
- Juan Sun
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China
| | - Junya Ding
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China
| | - Ningwu Liu
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China
| | - Guangxiang Yang
- Chongqing Engineering Laboratory for Detection, Control and Integrated System, Chongqing Technology and Business University, 400067 Chongqing, China
| | - Jingsong Li
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China.
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