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Ma G, He Y, Chen B, Deng H, Liu Y, Wang X, Zhao Z, Kan R. Quasi-Simultaneous Sensitive Detection of Two Gas Species by Cavity-Ringdown Spectroscopy with Two Lasers. SENSORS (BASEL, SWITZERLAND) 2021; 21:7622. [PMID: 34833699 PMCID: PMC8624139 DOI: 10.3390/s21227622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 10/28/2021] [Accepted: 11/03/2021] [Indexed: 11/26/2022]
Abstract
We developed a cavity ringdown spectrometer by utilizing a step-scanning and dithering method for matching laser wavelengths to optical resonances of an optical cavity. Our approach is capable of working with two and more lasers for quasi-simultaneous measurements of multiple gas species. The developed system was tested with two lasers operating around 1654 nm and 1658 nm for spectral detections of 12CH4 and its isotope 13CH4 in air, respectively. The ringdown time of the empty cavity was about 340 µs. The achieved high detection sensitivity of a noise-equivalent absorption coefficient was 2.8 × 10-11 cm-1 Hz-1/2 or 1 × 10-11 cm-1 by averaging for 30 s. The uncertainty of the high precision determination of δ13CH4 in air is about 1.3‰. Such a system will be useful for future applications such as environmental monitoring.
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Affiliation(s)
- Guosheng Ma
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China; (G.M.); (Y.H.); (B.C.); (H.D.); (Y.L.)
- Graduate School of Science Island Branch, University of Science and Technology of China, Hefei 230026, China
| | - Yabai He
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China; (G.M.); (Y.H.); (B.C.); (H.D.); (Y.L.)
| | - Bing Chen
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China; (G.M.); (Y.H.); (B.C.); (H.D.); (Y.L.)
| | - Hao Deng
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China; (G.M.); (Y.H.); (B.C.); (H.D.); (Y.L.)
| | - Ying Liu
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China; (G.M.); (Y.H.); (B.C.); (H.D.); (Y.L.)
- Graduate School of Science Island Branch, University of Science and Technology of China, Hefei 230026, China
| | - Xingping Wang
- School of Engineering Science, University of Science and Technology of China, Hefei 230026, China;
| | - Zhihao Zhao
- College of Information Science and Engineering, Northeastern University, Shenyang 110819, China;
| | - Ruifeng Kan
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China; (G.M.); (Y.H.); (B.C.); (H.D.); (Y.L.)
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Lupascu M, Akhtar H, Smith TEL, Sukri RS. Post-fire carbon dynamics in the tropical peat swamp forests of Brunei reveal long-term elevated CH 4 flux. GLOBAL CHANGE BIOLOGY 2020; 26:5125-5145. [PMID: 32475055 DOI: 10.1111/gcb.15195] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 05/19/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
Tropical peatlands hold about 15%-19% of the global peat carbon (C) pool of which 77% is stored in the peat swamp forests (PSFs) of Southeast Asia. Nonetheless, these PSFs have been drained, exploited for timber and land for agriculture, leading to frequent fires in the region. The physico-chemical characteristics of peat, as well as the hydrology of PSFs are affected after a fire, during which the ecosystem can act as a C source for decades, as C emissions to the atmosphere exceed photosynthesis. In this work, we studied the longer-term impact of fires on C cycling in tropical PSFs, hence we quantified the magnitude and patterns of C loss (CO2 , CH4 and dissolved organic carbon) and soil-water quality characteristics in an intact and a degraded burnt PSF in Brunei Darussalam affected by seven fires over the last 40 years. We used natural tracers such as 14 C to investigate the age and sources of C contributing to ecosystem respiration (Reco ) and CH4 , while we continuously monitored soil temperature and water table (WT) level from June 2017 to January 2019. Our results showed a major difference in the physico-chemical parameters, which in turn affected C dynamics, especially CH4 . Methane effluxes were higher in fire-affected areas (7.8 ± 2.2 mg CH4 m-2 hr-1 ) compared to the intact PSF (4.0 ± 2.0 mg CH4 m-2 hr-1 ) due to prolonged higher WT and more optimal methanogenesis conditions. On the other hand, we did not find significant differences in Reco between burnt (432 ± 83 mg CO2 m-2 hr-1 ) and intact PSF (359 ± 76 mg CO2 m-2 hr-1 ). Radiocarbon analysis showed overall no significant difference between intact and burnt PSF with a modern signature for both CO2 and CH4 fluxes implying a microbial preference for the more labile C fraction in the peat matrix.
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Affiliation(s)
- Massimo Lupascu
- Department of Geography, National University of Singapore, Singapore, Singapore
- Integrated Tropical Peatland Research Program, NUS Environmental Research Institute, National University of Singapore, Singapore, Singapore
| | - Hasan Akhtar
- Department of Geography, National University of Singapore, Singapore, Singapore
| | - Thomas E L Smith
- Department of Geography and Environment, The London School of Economics and Political Science, London, UK
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Yuan F, Hu M, He Y, Chen B, Yao L, Xu Z, Kan R. Development of an in situ analysis system for methane dissolved in seawater based on cavity ringdown spectroscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:083106. [PMID: 32872969 DOI: 10.1063/5.0004742] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 06/08/2020] [Indexed: 06/11/2023]
Abstract
This paper reports the development of a compact in situ real-time concentration analysis system for methane dissolved in seawater by using a continuous-wave cavity ringdown spectroscopy (CRDS) technique. The miniaturized design of the system, including optical resonance cavity and control and data acquisition-analysis electronics, has a cylindrical dimension of 550 mm in length and 100 mm in diameter. Ringdown signal generation, data acquisition and storage, current driver, and temperature controller of the diode laser are all integrated in the miniaturized system circuits, with an electrical power consumption of less than 12 W. Fitting algorithms of the ringdown signal and spectral line are implemented in a digital signal processor, which is the main control chip of the system circuit. The detection sensitivity for methane concentration can reach 0.4 ppbv with an approximate averaging time of 240 s (or 4 min). Comparing the system's measurement of ambient air against a high-quality commercial CRDS instrument has demonstrated a good agreement in results. In addition, as a "proof of concept" for measuring dissolved methane, the developed instrument was tested in an actual underwater environment. The results showed the potential of this miniaturized portable instrument for in situ gas sensing applications.
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Affiliation(s)
- Feng Yuan
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
| | - Mai Hu
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
| | - Yabai He
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
| | - Bing Chen
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
| | - Lu Yao
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
| | - Zhenyu Xu
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
| | - Ruifeng Kan
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
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Dong J, Liu L, Ji X, Shang Q, Liu L, Su L, Chen B, Kan R, Zhou Y, Yin SF, Han LB. General Oxidative Aryl C–P Bond Formation through Palladium-Catalyzed Decarbonylative Coupling of Aroylhydrazides with P(O)H Compounds. Org Lett 2019; 21:3198-3203. [DOI: 10.1021/acs.orglett.9b00922] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Jianyu Dong
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
- Department of Educational Science, Hunan First Normal University, Changsha 410205, China
| | - Long Liu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Xuyu Ji
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Qian Shang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Lixin Liu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Lebin Su
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Bing Chen
- Key Lab of Environmental Optics & Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
| | - Ruifeng Kan
- Key Lab of Environmental Optics & Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
| | - Yongbo Zhou
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Shuang-Feng Yin
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Li-Biao Han
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan
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Chen B, Wang J, Sun YR, Kang P, Liu AW, Li JY, He XL, Hu SM. Broad-Range Detection of Water Vapor using Cavity Ring-down Spectrometer. CHINESE J CHEM PHYS 2015. [DOI: 10.1063/1674-0068/28/cjcp1507160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Chen B, Kang P, Li JY, He XL, Liu AW, Hu SM. Quantitative Moisture Measurement with a Cavity Ring-down Spectrometer using Telecom Diode Lasers. CHINESE J CHEM PHYS 2015. [DOI: 10.1063/1674-0068/28/cjcp1410185] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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