中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Application of an absolute reference frame for methane clumped-isotope analyses

文献类型:期刊论文

作者Liu, Qingmei3,4,6; Li, Jiacheng3,4,6; Jiang, Wenmin4,6; Li, Yun4,6; Lin, Mang2,4; Liu, Wen3,4,6; Shuai, Yanhua1; Zhang, Haizu5; Peng, Ping'an4,6; Xiong, Yongqiang4,6
刊名CHEMICAL GEOLOGY
出版日期2024-02-20
卷号646页码:9
关键词Methane Clumped isotopes High-resolution gas-source isotope-ratio mass spectrometry Absolute reference frame Formation temperature
ISSN号0009-2541
DOI10.1016/j.chemgeo.2024.121922
英文摘要Clumped-isotope analysis provides new constraints on the formation and evolution of methane. High-resolution isotope-ratio mass spectrometry (HR-IRMS) is a sensitive, precise, and stable analytical technique increasingly used in methane clumped-isotope analysis. However, the lack of standard reference frames hinders the comparison of data from different laboratories and the evaluation of accuracy. In this study, an absolute reference frame was introduced for HR-IRMS analysis of the multiply substituted methane isotopologues (CH3D)-C-13 and (CH2D2)-C-12. We evaluated the optimized performance of a Panorama (Nu Instruments, UK) HR-IRMS system by repeated analysis of an intra-laboratory standard gas, finding that these rare isotopologues can be analyzed separately with high precision, repeatability, and reproducibility. Internal precision (a key parameter in instrument performance) reached 0.15 parts per thousand - 0.25 parts per thousand for Delta(CH3D)-C-13 and 0.70 parts per thousand - 0.85 parts per thousand for Delta(CH2D2)-C-12 values, ensuring the reliability of data. Comparison of results before and after purification demonstrated that purification procedures caused negligible isotopic fractionation of clumped isotopes. Isotopic-exchange experiments revealed source effects in the MS ion source, depending on the difference in bulk H isotopic composition between sample and reference gas, but independent of bulk C isotopic composition. To improve analytical accuracy for methane isotopologues, an absolute reference frame was developed through experiments involving a suite of mixed gases of different H isotopic composition equilibrated at 100 degrees C and a standard gas equilibrated at 2 degrees C-500 degrees C. Based on the reference frame, raw data were processed with a non-linearity correction and converted to real values with empirical transformation functions. The reference frame was applied to analyses of two methane standard gases and three natural gases from Tarim Basin, China. Measured Delta(CH3D)-C-13 and Delta(CH2D2)-C-12 values for two standard gases were consistent with published values. Clumped-isotope signatures of natural gases preserve information related to the formation temperature of methane.
WOS研究方向Geochemistry & Geophysics
语种英语
WOS记录号WOS:001156367000001
源URL[http://ir.gig.ac.cn/handle/344008/76218]  
专题有机地球化学国家重点实验室
通讯作者Xiong, Yongqiang
作者单位1.Petrochina Res Inst Petr Explorat & Dev, Beijing, Peoples R China
2.Chinese Acad Sci, State Key Lab Isotope Geochem, Guangzhou Inst Geochem, Guangzhou 510640, Peoples R China
3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
4.CAS Ctr Excellence Deep Earth Sci, Guangzhou 510640, Peoples R China
5.Petrochina Tarim Oilfield Co, Kuerle 841000, Peoples R China
6.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Organ Geochem, Guangzhou 510640, Peoples R China
推荐引用方式
GB/T 7714
Liu, Qingmei,Li, Jiacheng,Jiang, Wenmin,et al. Application of an absolute reference frame for methane clumped-isotope analyses[J]. CHEMICAL GEOLOGY,2024,646:9.
APA Liu, Qingmei.,Li, Jiacheng.,Jiang, Wenmin.,Li, Yun.,Lin, Mang.,...&Xiong, Yongqiang.(2024).Application of an absolute reference frame for methane clumped-isotope analyses.CHEMICAL GEOLOGY,646,9.
MLA Liu, Qingmei,et al."Application of an absolute reference frame for methane clumped-isotope analyses".CHEMICAL GEOLOGY 646(2024):9.

入库方式: OAI收割

来源:广州地球化学研究所

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