Methane clumped isotopes: Research progress and application in carbon cycling in Earth surface systems

doi:10.13745/j.esf.sf.2022.2.74

Abstract

Abstract:

Clumped isotopes are a frontier field of geochemical research today. Basic researches on the technical principles of clumped isotope techniques, indicative value of clumped isotopes, clumped isotope calibration, etc. have yielded preliminary results; whereas applications of clumped isotopes are scarce in the study of Earth surface systems as well as in geography, environmental sciences and ecology. In Earth surface systems, carbon cycling has far-reaching implications, and for methane (CH₄), an important part of the natural carbon cycle, revealing its source and geochemical process is of great importance. The introduction of methane clumped isotope method can provide an effective tool as likely it can be used to reveal carbon cycling at different scales in time and space. This article summarizes the theoretical basis of clumped isotopes and the current test analysis results, with focuses on the research status and theoretical models of methane clumped isotopes as well as the factors influencing isotopic disequilibrium, and discusses typical applications of clumped isotopes in studying methanogenesis and CH₄ transformation in natural gas, atmosphere and water. Finally, test result comparisons between different laboratories, sample collection under natural isotopic abundances, and discussion on quasi-equilibrium process are put forward to provide a reference for future application of methane clumped isotopes and others, such as carbon dioxide clumped isotopes, in studying carbon cycling in Earth surface systems.

Key words: clumped isotopes, methane, carbon dioxide, Earth surface systems, carbon cycle

CLC Number:

P593
X142

WANG Xinchu, LIU Congqiang, LI Siliang, XU Sheng, DING Hu, PANG Zhiyong, SHUAI Yanhua. Methane clumped isotopes: Research progress and application in carbon cycling in Earth surface systems[J]. Earth Science Frontiers, 2023, 30(2): 463-478.

Figures/Tables 8

References 125

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气体	质量/amu	准确质量/amu	同位素分子	相对丰度	前提	来源文献
CH₄	16	16.031	¹²CH₄	98.80%	假设甲烷δ¹³C=0‰, δD=0‰	[40]
	17	17.035	¹³CH₄	1.11×10^-2
		17.038	¹²CH₃D	6.16×10^-4
	18	18.041	¹³CH₃D	6.92×10^-6
		18.044	¹²CH₂D₂	1.44×10^-7
	19	19.047	¹³CH₂D₂	1.62×10^-9
		19.050	¹²CHD₃	1.49×10^-11
	20	20.053	¹³CHD₃	4.68×10^-13
		20.056	¹²CD₄	5.82×10^-16
	21	21.060	¹³CD₄	6.54×10^-18
气体	质量/amu	准确质量/amu	同位素分子	相对丰度	前提	来源文献
CO₂	44	44.001	¹²C¹⁶O₂	98.4%	假设¹⁷O/¹⁶O和¹⁸O/¹⁶O 比值等于VSMOW标准, ¹³C/¹²C比值等于PDB标准	[35]
	45	44.993	¹³C¹⁶O₂	1.11×10^-2
		45.005	¹²C¹⁷O¹⁶O	7.48×10^-6
	46	46.005	¹²C¹⁸O¹⁶O	4.00×10^-3
		45.997	¹³C¹⁷O¹⁶O	8.4×10^-6
		46.009	¹²C¹⁷O₂	1.42×10^-7
	47	46.997	¹³C¹⁸O¹⁶O	44.4×10^-6
		47.009	¹²C¹⁷O¹⁸O	1.50×10^-6
		47.001	¹³C¹⁷O₂	1.60×10^-9
	48	48.009	¹²C¹⁸O₂	3.96×10^-6
		48.001	¹³C¹⁷O¹⁸O	1.68×10^-9
	49	49.001	¹³C¹⁸O₂	4.45×10^-9

气体	质量/amu	准确质量/amu	同位素分子	相对丰度	前提	来源文献
CH₄	16	16.031	¹²CH₄	98.80%	假设甲烷δ¹³C=0‰, δD=0‰	[40]
	17	17.035	¹³CH₄	1.11×10^-2
		17.038	¹²CH₃D	6.16×10^-4
	18	18.041	¹³CH₃D	6.92×10^-6
		18.044	¹²CH₂D₂	1.44×10^-7
	19	19.047	¹³CH₂D₂	1.62×10^-9
		19.050	¹²CHD₃	1.49×10^-11
	20	20.053	¹³CHD₃	4.68×10^-13
		20.056	¹²CD₄	5.82×10^-16
	21	21.060	¹³CD₄	6.54×10^-18
气体	质量/amu	准确质量/amu	同位素分子	相对丰度	前提	来源文献
CO₂	44	44.001	¹²C¹⁶O₂	98.4%	假设¹⁷O/¹⁶O和¹⁸O/¹⁶O 比值等于VSMOW标准, ¹³C/¹²C比值等于PDB标准	[35]
	45	44.993	¹³C¹⁶O₂	1.11×10^-2
		45.005	¹²C¹⁷O¹⁶O	7.48×10^-6
	46	46.005	¹²C¹⁸O¹⁶O	4.00×10^-3
		45.997	¹³C¹⁷O¹⁶O	8.4×10^-6
		46.009	¹²C¹⁷O₂	1.42×10^-7
	47	46.997	¹³C¹⁸O¹⁶O	44.4×10^-6
		47.009	¹²C¹⁷O¹⁸O	1.50×10^-6
		47.001	¹³C¹⁷O₂	1.60×10^-9
	48	48.009	¹²C¹⁸O₂	3.96×10^-6
		48.001	¹³C¹⁷O¹⁸O	1.68×10^-9
	49	49.001	¹³C¹⁸O₂	4.45×10^-9

作者	机构	时间	仪器	Δ¹³CH₃D精度 (± 1 SE)	Δ¹²CH₂D₂精度 (± 1 SE)
Stolper等^[40]	加州理工学院	2014	253 Ultra原型机	±0.23‰
Wang等^[23]	麻省理工学院	2015	可调谐激光光谱仪	±0.42‰
Shuai等^[51]	加州理工学院	2018	253 Ultra原型机	±0.23‰
Eldridge等^[82]	伯克利大学	2019	253 Ultra	±0.33‰	±1.35‰
Giunta等^[55]	加州大学洛杉矶分校	2019	Nu Panorama	±0.30‰	±1.00‰
Zhang等^[56]	东京工业大学	2021	253 Ultra	±0.31‰	±1.24‰
庞智勇^[83]	天津大学	2021	253 Ultra	±0.27‰	±1.35‰

作者	机构	时间	仪器	Δ¹³CH₃D精度 (± 1 SE)	Δ¹²CH₂D₂精度 (± 1 SE)
Stolper等^[40]	加州理工学院	2014	253 Ultra原型机	±0.23‰
Wang等^[23]	麻省理工学院	2015	可调谐激光光谱仪	±0.42‰
Shuai等^[51]	加州理工学院	2018	253 Ultra原型机	±0.23‰
Eldridge等^[82]	伯克利大学	2019	253 Ultra	±0.33‰	±1.35‰
Giunta等^[55]	加州大学洛杉矶分校	2019	Nu Panorama	±0.30‰	±1.00‰
Zhang等^[56]	东京工业大学	2021	253 Ultra	±0.31‰	±1.24‰
庞智勇^[83]	天津大学	2021	253 Ultra	±0.27‰	±1.35‰