Method for Analyzing the Molecular and Carbon Isotope Composition of Volatile Hydrocarbons (C1–C9) in Natural Gas
Solid-phase microextraction (SPME) coupled with gas chromatography-isotope ratio mass spectrometry (GC-IRMS) has already been applied to collect and identify volatile light hydrocarbons in oil and source rocks. However, this technology has not yet been used to analyze volatile light hydrocarbons in...
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| Format: | Article |
| Language: | English |
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Wiley
2018-01-01
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| Series: | Journal of Analytical Methods in Chemistry |
| Online Access: | http://dx.doi.org/10.1155/2018/4512081 |
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| author | Chunhui Cao Zhongping Li Liwu Li Li Du |
| author_facet | Chunhui Cao Zhongping Li Liwu Li Li Du |
| author_sort | Chunhui Cao |
| collection | DOAJ |
| description | Solid-phase microextraction (SPME) coupled with gas chromatography-isotope ratio mass spectrometry (GC-IRMS) has already been applied to collect and identify volatile light hydrocarbons in oil and source rocks. However, this technology has not yet been used to analyze volatile light hydrocarbons in dry gas (natural gas with C1/C2+ > 95%). In this study, we developed a method to measure the molecular and carbon isotope composition of natural gas using divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber. This fiber proved to be suitable for extracting C1–C9 hydrocarbons from natural gas without inducing carbon isotopic fractionation. Notably, the extraction coefficients of the analytes were not the same but rather increased with the increasing carbon number of the hydrocarbons. Nevertheless, we successfully identified 24 hydrocarbons from the in-lab standard natural gas, while also obtaining the carbon isotope composition of C1 to C9 hydrocarbons with satisfying repeatability. The relative standard deviation (RSD) of the molecular composition data was in the range of 0.06–0.74%, with the RSDs of the carbon isotope composition data not exceeding 1‰. Finally, seven natural gas samples, collected from different sedimentary basins, were successfully analyzed and the stable carbon isotope compositions of C1–C9 hydrocarbons present in these were determined through this method. Overall, the new approach provides a simple but useful technique to obtain more geochemical information about the source and evolution of natural gas. |
| format | Article |
| id | doaj-art-b739ea33e4ee4f8cb9d68a0affc454a4 |
| institution | OA Journals |
| issn | 2090-8865 2090-8873 |
| language | English |
| publishDate | 2018-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Journal of Analytical Methods in Chemistry |
| spelling | doaj-art-b739ea33e4ee4f8cb9d68a0affc454a42025-08-20T02:19:19ZengWileyJournal of Analytical Methods in Chemistry2090-88652090-88732018-01-01201810.1155/2018/45120814512081Method for Analyzing the Molecular and Carbon Isotope Composition of Volatile Hydrocarbons (C1–C9) in Natural GasChunhui Cao0Zhongping Li1Liwu Li2Li Du3Key Laboratory of Petroleum Resources, Gansu Province/Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000, ChinaKey Laboratory of Petroleum Resources, Gansu Province/Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000, ChinaKey Laboratory of Petroleum Resources, Gansu Province/Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000, ChinaKey Laboratory of Petroleum Resources, Gansu Province/Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000, ChinaSolid-phase microextraction (SPME) coupled with gas chromatography-isotope ratio mass spectrometry (GC-IRMS) has already been applied to collect and identify volatile light hydrocarbons in oil and source rocks. However, this technology has not yet been used to analyze volatile light hydrocarbons in dry gas (natural gas with C1/C2+ > 95%). In this study, we developed a method to measure the molecular and carbon isotope composition of natural gas using divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber. This fiber proved to be suitable for extracting C1–C9 hydrocarbons from natural gas without inducing carbon isotopic fractionation. Notably, the extraction coefficients of the analytes were not the same but rather increased with the increasing carbon number of the hydrocarbons. Nevertheless, we successfully identified 24 hydrocarbons from the in-lab standard natural gas, while also obtaining the carbon isotope composition of C1 to C9 hydrocarbons with satisfying repeatability. The relative standard deviation (RSD) of the molecular composition data was in the range of 0.06–0.74%, with the RSDs of the carbon isotope composition data not exceeding 1‰. Finally, seven natural gas samples, collected from different sedimentary basins, were successfully analyzed and the stable carbon isotope compositions of C1–C9 hydrocarbons present in these were determined through this method. Overall, the new approach provides a simple but useful technique to obtain more geochemical information about the source and evolution of natural gas.http://dx.doi.org/10.1155/2018/4512081 |
| spellingShingle | Chunhui Cao Zhongping Li Liwu Li Li Du Method for Analyzing the Molecular and Carbon Isotope Composition of Volatile Hydrocarbons (C1–C9) in Natural Gas Journal of Analytical Methods in Chemistry |
| title | Method for Analyzing the Molecular and Carbon Isotope Composition of Volatile Hydrocarbons (C1–C9) in Natural Gas |
| title_full | Method for Analyzing the Molecular and Carbon Isotope Composition of Volatile Hydrocarbons (C1–C9) in Natural Gas |
| title_fullStr | Method for Analyzing the Molecular and Carbon Isotope Composition of Volatile Hydrocarbons (C1–C9) in Natural Gas |
| title_full_unstemmed | Method for Analyzing the Molecular and Carbon Isotope Composition of Volatile Hydrocarbons (C1–C9) in Natural Gas |
| title_short | Method for Analyzing the Molecular and Carbon Isotope Composition of Volatile Hydrocarbons (C1–C9) in Natural Gas |
| title_sort | method for analyzing the molecular and carbon isotope composition of volatile hydrocarbons c1 c9 in natural gas |
| url | http://dx.doi.org/10.1155/2018/4512081 |
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