Nitrogen Isotope Analysis Method of Organic-enriched Shale

HU Zhizhong; YAN Xiong; JIN Lu; ZHAO Ankun; XU Guodong; DU Gu

doi:10.15898/j.ykcs.202212090231

Rock and Mineral Analysis > 2023 > 42(4): 677-690. > DOI: 10.15898/j.ykcs.202212090231

HU Zhizhong，YAN Xiong，JIN Lu，et al. Nitrogen Isotope Analysis Method of Organic-enriched Shale[J]. Rock and Mineral Analysis，2023，42（4）：677−690. DOI: 10.15898/j.ykcs.202212090231

Citation:

HU Zhizhong，YAN Xiong，JIN Lu，et al. Nitrogen Isotope Analysis Method of Organic-enriched Shale[J]. Rock and Mineral Analysis，2023，42（4）：677−690. DOI: 10.15898/j.ykcs.202212090231

Citation:

HU Zhizhong，YAN Xiong，JIN Lu，et al. Nitrogen Isotope Analysis Method of Organic-enriched Shale[J]. Rock and Mineral Analysis，2023，42（4）：677−690. DOI: 10.15898/j.ykcs.202212090231

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Nitrogen Isotope Analysis Method of Organic-enriched Shale

HU Zhizhong^{1, 2,},
YAN Xiong^{1, 2},
JIN Lu^{1, 2},
ZHAO Ankun^{1, 2},
XU Guodong^{1, 2},
DU Gu^{1, 2}

1.
Chengdu Center, China Geological Survey (Geosciences Innovation Center of Southwest China), Chengdu 610081, China
2.
Key Laboratory of Sedimentary Basin and Oil and Gas Resources, Ministry of Natural Resources, Chengdu 610081, China

More Information

Received Date: December 08, 2022
Revised Date: February 20, 2023
Accepted Date: March 28, 2023
Available Online: June 19, 2023

Abstract

ABSTRACT

BACKGROUND
Shale, as an important component of sedimentary rocks, is also a valuable source rock and “reservoir” of shale gas. The study of nitrogen isotope distribution characteristics can provide geochemical indexes for judging the sedimentary environment and oil-source correlation of crude oil. It is helpful to understand the organic matter enrichment mechanism of black shale, shale oil, and gas exploration^[14-17]. Nitrogen isotope ratio analysis in sedimentary rocks is faced with problems such as low content, and the influence of pretreatment on analysis and the reference materials, which affect the accurate analysis of nitrogen isotope ratio in shale and restrict the development of this technology in related studies. First, the low content in rocks will affect the analysis results by elemental analyzer-isotope ratio mass spectrometry (EA-IRMS)^[16,18,20]. Second, the method of direct sample analysis is often used to analyze nitrogen isotope ratio of whole rock, to improve the relative content of nitrogen and remove carbonate to meet the requirement of organic carbon isotope analysis; samples treated with acid can also be used for analysis. There are differences in treatment methods in different laboratories, which can also increase the variation in content and isotope ratios, as well as the difficulty of data comparison^[9-13,21,25]. Finally, there are relatively few international standard materials based on rocks and minerals for nitrogen isotope and there are still some problems and limitations in these standards^[7,21,24,30]. Therefore, the accurate analysis of nitrogen isotope ratio in shale is affected, thus restricting the development of this technology in related studies.
OBJECTIVES
To improve the precision and accuracy of nitrogen isotope analysis in shales.
METHODS
(1) The analysis was carried out by EA-IRMS, with the use of MAT253 Plus gas stable isotope mass spectrometer, Flash 2000 HT element analyzer and ConFlo Ⅳ interface. The furnace tube was filled with the recommended scheme of the instrument, and the water removal trap was adjusted according to the measured object, that is, only magnesium perchlorate was used or carbon adsorbent was added on this basis (the main component was sodium hydroxide), which accounted for 50% each. Carbon and nitrogen isotope ratios were measured separately.　　(2) Carbon and nitrogen isotope standard materials included: USGS40, USGS41a, IAEA-600, Urea, GBW04701, GBW04702, GBW04703, GBW07424 and GBW07107 as calibration, monitoring and experimental study (Table 1). Typical shale samples of the upper Yangtze Longmaxi Formation were selected as the research object. Both samples are rich in organic carbon. Combined with hand samples and XRD analysis, their mineral composition is mainly as follows: Quartz, potassium feldspar, illite and pyrite in SAMPLE-1, SAMPLE-2 are similar in mineral composition in general, but there is obvious dolomite in SAMPLE-2.　　(3) The experiment consisted of three parts. First, the impact of increasing oxygen injection time and using double tin cup encapsulation on nitrogen isotope ratio analysis was studied. Urea was applied to determine δ¹⁵N under the same conditions but with different oxygen injection time (3s or 5s) and the differences were compared. Urea and GBW07424 were used to encapsulate the sample with double tin cup (two layers of tin cup for the same sample) and conventional single tin cup for comparison under the same conditions. The composition of total nitrogen and total carbon isotope ratios in GBW04701, GBW04702 and GBW04703 was determined by single-tin cup encapsulation. Second, the influence of acid rinse method on the analysis was conducted. Standards were weighed and gradually added with an excess of 6mol/L HCl to remove carbonate minerals. During the reaction, the centrifuge tube was placed in an ultrasonic cleaner for ultrasonic treatment for 3 to 5 times, 10min each time. Centrifuge was used, acid was discarded and deionized water was added. After ultrasonic treatment in ultrasonic cleaner, centrifuge treatment was continued. This process was repeated until it reached neutral. The samples were then compared and analyzed with unprocessed samples and recommended values. Finally, the shale samples SAMPLE-1 and SAMPLE-2 from Longmaxi Formation were analyzed. The isotopic ratios of total nitrogen and total carbon were determined respectively. The samples were treated with the above acid rinse method to analyze the ratio of organic carbon and nitrogen isotopes, and the mineral composition before and after treatment was analyzed by XRD. Nitrogen isotope difference and total carbon and organic carbon isotope ratio were analyzed before and after treatment.
RESULTS
The results of single/double tin cup method showed that the accuracy of δ¹⁵N value determined by double tin cup method were obviously worse than that by single tin cup method at the same oxygen injection time (Table 2). GBW07424 analysis showed that nitrogen amounts had more obvious influence on the analysis. The results of total nitrogen analysis in GBW04701, GBW04702 and GBW04703 measured under the condition of oxygen injection time 5s were consistent with the recommended values (Table 3), and the standard deviation of the samples was improved (SD≈0.1‰). After acid rinse, the nitrogen values of GBW04701 and GBW04702 were consistent with the recommended values (Table 3), and the relative deviation was better (SD<0.1‰). The overall carbon isotope ratio analysis values were consistent with the recommended values (Table 4). The difference of δ¹³C_VPDB between total carbon and organic carbon determined by GBW07107 was small and consistent with its carbon composition. The δ¹⁵N values of shale samples before and after acid treatment were basically the same in SAMPLE-1, while the δ¹⁵N values of shale samples after acid treatment were obviously changed in SAMPLE-2, which was related to the composition loss in the wash acid process of SAMPLE-2.
DISCUSSION
(1) The optimized measurement conditions of EA-IRMS. Attempts were made to improve combustion efficiency by using double tin cup wrapping and increasing oxygen injection time. The relative deviation of double tin cup method was greater than 0.2‰ and obviously higher than that of single tin cup method, indicating that this method is not suitable. The reason may be related to the difference in combustion efficiency caused by the gap between double tin cups and the introduction of air when the sample is wrapped^[19]. Appropriate increase of oxygen injection time in the analysis of GBW04701, GBW04702 and GBW04703 obtained satisfactory results, indicating that this method can effectively improve the accuracy of the technique, while this method did not significantly improve the standard deviation of δ¹⁵N value of Urea, which may be related to the matrix of the sample^[20]. It may be the abundant carbon in shale. Therefore, it is necessary for nitrogen isotope ratio analysis in shale to be determined by carbon and nitrogen separately and adding carbon adsorbent.　　(2) The acid rinse method. The acid rinse method adopted has no significant effect on GBW04701 and GBW04702 on δ¹⁵N analysis and can effectively remove carbonate components. Ultrasonic was used to promote the reaction between acid/water and sample in the process of acid reaction and acid washing in the experiment, and the centrifugation time was appropriately increased in the centrifugation stage, which was conducive to the preservation of fine particle components. Compared with static reaction, the addition of ultrasonic reaction could improve the washing effect. The less washing times were thus contributing to the accuracy of δ¹⁵N analysis^[47].　　(3) The shale sample analysis. Although the acid treatment method adopted in the experiment has no obvious effect on the δ¹⁵N analysis of standards, significant composition loss and δ¹⁵N change were still observed in the analysis of shale samples. Moreover, the nitrogen content of shale samples of Longmaxi Formation was relatively high. Therefore, in order to accurately analyze the nitrogen content and δ¹⁵N analysis, direct analysis of samples is recommended for the whole-rock nitrogen isotope analysis of such samples.　　(4) The standard and reference materials. Carbon and nitrogen isotope reference materials with different characters and compositions were selected as calibration, monitoring and experimental study. USGS40, USGS41a and IAEA-600 standard samples were used for calibration and quality monitoring, and no obvious influence of matrix difference was found. Although they are Marine sediments, GBW04701, GBW04702, GBW04703 provide isotopic compositions of total carbon, organic carbon, total nitrogen and organic nitrogen. They are suitable for the analysis of carbon and nitrogen isotope ratios and the monitoring of acid treatment processes, especially the analysis of EA-IRMS technology^[50]. In shale analysis, GBW04701, GBW04702 and GBW04703 were selected as monitoring to meet the requirements of nitrogen and total carbon and organic carbon isotope ratio analysis.
- shale,
- nitrogen isotope ratio,
- EA-IRMS,
- pretreatment method,
- standard

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References (56)

References

[1]	Stüeken E E, Buick R, Guy B M, et al. Isotopic evidence for biological nitrogen fixation by molybdenum-nitrogenase from 3.2Gyr[J]. Nature, 2015, 520: 666−669. doi: 10.1038/nature14180
[2]	Stüeken E E, Kipp M A, Koehler M C, et al. The evolution of Earth’s biogeochemical nitrogen cycle[J]. Earth-Science Reviews, 2016, 160: 220−239. doi: 10.1016/j.earscirev.2016.07.007
[3]	Kipp M A, Stüeken E E, Yun M, et al. Pervasive aerobic nitrogen cycling in the surface ocean across the Paleoproterozoic Era[J]. Earth and Planetary Science Letters, 2018, 500: 117−126. doi: 10.1016/j.jpgl.2018.08.007
[4]	曹亚澄, 张金波, 温腾, 等. 稳定同位素示踪技术与质谱分析——在土壤、生态、环境研究中的应用[M]. 北京: 科学出版社, 2018: 113-174. Cao Y C, Zhang J B, Wen T, et al. Stable isotope tracing and mass spectrometry—Applications in soil, ecology, and environmental studies[M]. Beijing: Science Press, 2018: 113-174.
[5]	Zerkle A L, Poulton S W, Newton R J, et al. Onset of the aerobic nitrogen cycle during the Great Oxidation Event[J]. Nature, 2017, 542: 465−467. doi: 10.1038/nature20826
[6]	Bingham N L, Slessarev E W, Homyak P M, et al. Rock-sourced nitrogen in semi-arid, shale-derived California soils[J]. Frontiers in Forests and Global Change, 2021, 4: 672522.
[7]	Stüeken E E, Buick R, Schauer A J. Nitrogen isotope evidence for alkaline lakes on late Archean continents[J]. Earth and Planetary Science Letters, 2015, 411: 1−10. doi: 10.1016/j.jpgl.2014.11.037
[8]	Chen J, Chen J F, Shi S B, et al. The linkage of nitrogen isotopic composition and depositional environment of black mudstones in the Upper Triassic Yanchang Formation, Ordos Basin, Northern China[J]. Journal of Asian Earth Sciences, 2020, 193: 104308. doi: 10.1016/j.jseaes.2020.104308
[9]	Hodgskiss M S W, Sansjofre P, Kunzmann M, et al. A high-TOC shale in a low productivity world: The late Mesoproterozoic Arctic Bay Formation, Nunavut[J]. Earth and Planetary Science Letters, 2020, 544: 116384. doi: 10.1016/j.jpgl.2020.116384
[10]	Wang X Q, Jiang G Q, Shi X Y, et al. Nitrogen isotope constraints on the early Ediacaran ocean redox structure[J]. Geochimica et Cosmochimica Acta, 2018, 240: 220−235. doi: 10.1016/j.gca.2018.08.034
[11]	Yang X R, Yan D T, Chen D Z, et al. Spatiotemporal variations of sedimentary carbon and nitrogen isotopic compositions in the Yangtze Shelf Sea across the Ordovician—Silurian boundary[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2021, 567: 110257. doi: 10.1016/j.palaeo.2021.110257
[12]	Wei W, Lu Y C, Ma Y Q, et al. Nitrogen isotopes as paleoenvironmental proxies in marginal-marine shales, Bohai Bay Basin, NE China[J]. Sedimentary Geology, 2021, 421: 105963. doi: 10.1016/j.sedgeo.2021.105963
[13]	Zhu G Y, Wang P J, Li T T, et al. Nitrogen geochemistry and abnormal mercury enrichment of shales from the lowermost Cambrian Niutitang Formation in South China: Implications for the marine redox conditions and hydrothermal activity[J]. Global and Planetary Change, 2021, 199: 103449. doi: 10.1016/j.gloplacha.2021.103449
[14]	Hossain H M Z, Sampei Y, Hossain Q H, et al. Origin of organic matter and hydrocarbon potential of Permian Gondwana coaly shales intercalated in coals/sands of the Barapukuria Basin, Bangladesh[J]. International Journal of Coal Geology, 2019, 212: 103201. doi: 10.1016/j.coal.2019.05.008
[15]	李婷婷, 朱光有, 赵坤, 等. 氮循环及氮同位素在古老烃源岩形成环境重建与油源对比中的应用[J]. 天然气地球科学, 2020, 31(5): 721−734. Li T T, Zhu G Y, Zhao K, et al. Nitrogen cycle and nitrogen isotope application in paleoenvironment reconstruction of ancient hydrocarbon source rocks and oil-source correlations[J]. Natural Gas Geoscience, 2020, 31(5): 721−734.
[16]	栗敏. 典型沉积环境中沉积有机质氮同位素组成特征及地质意义[D]. 北京: 中国石油大学(北京), 2018: 1-6. Li M. Nitrogen isotope composition characteristics and geological significance of organic matter in typical sedimentary environment[D]. Beijing: China University of Petroleum (Beijing), 2018: 1-6.
[17]	周晶晶. 中上扬子地区五峰—龙马溪组页岩氮同位素分布特征及古环境研究[D]. 北京: 中国矿业大学(北京), 2021: 1-8. Zhou J J. Distribution characteristics of nitrogen isotope and paleoenvironment of shale from Wufeng—Longmaxi Formation in middle and upper Yangtze Region, China[D]. Beijing: China University of Geosciences (Beijing), 2021: 1-8.
[18]	尹希杰, 刘维维, 王永涛, 等. 元素分析-同位素质谱联用测定微量氮元素同位素方法研究[J]. 质谱学报, 2021, 42(3): 346−352. Yin X J, Liu W W, Wang Y T, et al. Determination of δ¹⁵N on microgram amounts by modified element analysis-isotope ratio mass spectrometry[J]. Journal of Chinese Mass Spectrometry Society, 2021, 42(3): 346−352.
[19]	Langel R, Dyckmans J. A closer look into the nitrogen blank in elemental analyser/isotope ratio mass spectrometry measurements[J]. Rapid Communications in Mass Spectrometry, 2017, 31(23): 2051−2055. doi: 10.1002/rcm.7999
[20]	Wang N, Liu J Y, Zhang Y, et al. Influences of oxidation ability on precision in nitrogen isotope measurements of organic reference materials using elemental analysis-isotope ratio mass spectrometry[J]. Rapid Communications in Mass Spectrometry, 2021, 35: e9122.
[21]	Stüeken E E, Castro M, Krotz L, et al. Optimized switch‐over between CHNS abundance and CNS isotope ratio analyses by elemental analyzer‐isotope ratio mass spectrometry: Application to six geological reference materials[J]. Rapid Communications in Mass Spectrometry, 2020, 34(18): e8821.
[22]	Kubota R. Simultaneous determination of total carbon, nitrogen, hydrogen and sulfur in twenty-seven geological reference materials by elemental analyser[J]. Geostandards and Geoanalytical Research, 2009, 33: 271−283. doi: 10.1111/j.1751-908X.2009.00905.x
[23]	徐丽, 邢蓝田, 王鑫, 等. 元素分析仪-同位素比值质谱测量碳氮同位素比值最佳反应温度和进样量的确定[J]. 岩矿测试, 2018, 37(1): 15−20. Xu L, Xing L T, Wang X, et al. Study on the optimal reaction temperature and sampling weight for measurement of carbon and nitrogen isotope ratio by elemental analysis-isotope ratio mass spectrometer[J]. Rock and Mineral Analysis, 2018, 37(1): 15−20.
[24]	Han W N, Feng L J, Li H W, et al. Bulk δ¹⁵N measurements of organic-rich rock samples by elemental analyzer/isotope ratio mass spectrometry with enhanced oxidation ability[J]. Rapid Communications in Mass Spectrometry, 2017, 31(1): 16−20. doi: 10.1002/rcm.7754
[25]	Stüeken E E, Zaloumis J, Meixnerová J, et al. Differential metamorphic effects on nitrogen isotopes in kerogen extracts and bulk rocks[J]. Geochimica et Cosmochimica Acta, 2017, 217: 80−94. doi: 10.1016/j.gca.2017.08.019
[26]	Fujisaki W, Matsui Y, Ueda H, et al. Pre-treatment methods for accurate determination of total nitrogen and organic carbon contents and their stable isotopic compositions: Re-evaluation from geological reference materials[J]. Geostandards and Geoanalytical Research, 2021, 46(1): 5−19.
[27]	彭亚君, 王玉珏, 刘东艳, 等. 酸化过程对海洋沉积物中有机碳同位素分析的影响[J]. 海洋学报, 2015, 37(12): 85−92. Peng Y J, Wang Y J, Liu D Y, et al. Acid treatment effects on the carbon stable isotope values of marine sediments[J]. Haiyang Xuebao, 2015, 37(12): 85−92.
[28]	Kim M S, Lee W S, Kumar K S, et al. Effects of HCl pretreatment, drying, and storage on the stable isotope ratios of soil and sediment samples[J]. Rapid Communications in Mass Spectrometry, 2016, 30: 1567−1575. doi: 10.1002/rcm.7600
[29]	Pasquier V, Sansjofre P, Lebeau O, et al. Acid digestion on river influenced shelf sediment organic matter: Carbon and nitrogen contents and isotopic ratios[J]. Rapid Communications in Mass Spectrometry, 2018, 32: 86−92.
[30]	Dennen K O, Johnson C A, Otter M L, et al. δ¹⁵N and non-carbonate δ¹³C values for two petroleum source rock reference materials and a marine sediment reference material[R]. U. S. Geological Survey Open-File Report, 2006.
[31]	Wu Y W, Tian H, Li T F, et al. Enhanced terrestrial organic matter burial in the marine shales of Yangtze Platform during the early Carboniferous interglacial interval[J]. Marine and Petroleum Geology, 2021, 129: 105064. doi: 10.1016/j.marpetgeo.2021.105064
[32]	丁悌平. 稳定同位素测试技术与参考物质研究现状及发展趋势[J]. 岩矿测试, 2002, 21(4): 291−300. doi: 10.3969/j.issn.0254-5357.2002.04.011 Ding T P. Present status and prospect of analytical techniques and reference materials for stable isotopes[J]. Rock and Mineral Analysis, 2002, 21(4): 291−300. doi: 10.3969/j.issn.0254-5357.2002.04.011
[33]	Gentile N, Rossi M J, Delémont O, et al. δ¹⁵N measurement of organic and inorganic substances by EA-IRMS: A speciation-dependent procedure[J]. Analytical and Bioanalytical Chemistry, 2013, 405(1): 159−176. doi: 10.1007/s00216-012-6471-z
[34]	Lott M J, Howa J D, Chesson L A, et al. Improved accuracy and precision in δ¹⁵N_AIR measurements of explosives, urea, and inorganic nitrates by elemental analyzer/isotope ratio mass spectrometry using thermal decomposition[J]. Rapid Communications in Mass Spectrometry, 2015, 29: 1381−1388. doi: 10.1002/rcm.7229
[35]	Feng L J, Li H W, Liu W. Nitrogen mass fraction and isotope determinations in geological reference materials using sealed-tube combustion coupled with continuous flow isotope-ratio mass spectrometry[J]. Geostandards and Geoanalytical Research, 2018, 42(4): 539−548. doi: 10.1111/ggr.12234
[36]	Feng L J, Li H W, Yan D T. A refinement of nitrogen isotope analysis of coal using elemental analyzer/isotope ratio mass spectrometry and the carbon and nitrogen isotope compositions of coals imported in China[J]. ACS Omega, 2020, 5: 7636−7640. doi: 10.1021/acsomega.0c00488
[37]	Zhao A K, Yu Q, Lei Z H, et al. Geological and microstructural characterization of the Wufeng—Longmaxi shale in the Basin—Orogen Transitional Belt of North Guizhou Province, China[J]. Journal of Nanoscience and Nanotechnology, 2017, 17(9): 6026−6038. doi: 10.1166/jnn.2017.14522
[38]	赵安坤, 时志强, 王学峰, 等. 康滇古陆东侧上奥陶统五峰组—下志留统龙马溪组富有机质白云石特征及其地质意义[J]. 矿物岩石地球化学通报, 2022, 41(2): 307−316. Zhao A K, Shi Z Q, Wang X F, et al. Characteristics of organic-rich dolomites from upper Ordovician Wufeng Formation—lower Silurian Longmaxi Formation in the eastern part of Kangdian ancient land and their geological significances[J]. Bulletin of Mineralogy, Petrology and Geochemistry, 2022, 41(2): 307−316.
[39]	杨熙雅, 刘成林, 刘文平, 等. 四川盆地富顺—永川地区龙马溪组页岩有机孔特征及其影响因素[J]. 石油与天然气地质, 2021, 42(6): 1321−1333. Yang X Y, Liu C L, Liu W P, et al. Characteristics of and factors influencing organic pores in the lower Silurian Longmaxi Formation, Fushun—Yongchuan area, Sichuan Basin[J]. Oil and Gas Geology, 2021, 42(6): 1321−1333.
[40]	何龙, 王云鹏, 陈多福. 四川盆地晚奥陶世有机碳、氮同位素异常及其古环境意义[J]. 地球化学, 2021, 50(6): 623−634. He L, Wang Y P, Chen D F, et al. Organic carbon and nitrogen isotope anomalies during the late Ordovician in Sichuan Basin, and their implications for the palaeoenvironment[J]. Geochimica, 2021, 50(6): 623−634.
[41]	黄玮. 早志留世海洋化学条件的变化及其对晚埃隆阶笔石多样性锐减的影响: 来自华南的证据[D]. 合肥: 中国科学技术大学, 2020: 1-2. Huang W. Redox condition changes in early Silurian ocean and their influence on the late Aeronian sedgwickii event: Evidence from South China[D]. Hefei: University of Science and Technology of China, 2020: 1-2.
[42]	胡志中, 晏雄, 王坤阳, 等. 碳酸盐碳氧同位素标准物质性状对分析和保存的影响[J]. 岩矿测试, 2021, 40(4): 476−490. Hu Z Z, Yan X, Wang K Y, et al. Characteristics of carbon and oxygen isotope standard materials of carbonates and their effect on isotope analysis and standard preservation[J]. Rock and Mineral Analysis, 2021, 40(4): 476−490.
[43]	曹亚澄. 气体同位素质谱分析300问[M]. 北京: 科学出版社, 2020: 79-80. Cao Y C. Gas isotope mass spectrometry 300 question[M]. Beijing: Science Press, 2020: 79-80.
[44]	吴夏, 黄俊华, 白晓, 等. 沉积岩总有机质碳同位素分析的前处理影响[J]. 地球学报, 2008, 29(6): 677−683. Wu X, Huang J H, Bai X, et al. Sample-pretreatment effects on analytical results of total organic carbon isotopes in sedimentary rocks[J]. Acta Geoscientica Sinica, 2008, 29(6): 677−683.
[45]	Brodie C R, Heaton T H E, Leng M J, et al. Evidence for bias in measured δ¹⁵N values of terrestrial and aquatic organic materials due to pre-analysis acid treatment methods[J]. Rapid Communications in Mass Spectrometry, 2011, 25: 1089−1099. doi: 10.1002/rcm.4970
[46]	Brodie C R, Leng M J, Casford J S L, et al. Evidence for bias in C and N concentrations and δ¹³C composition of terrestrial and aquatic organic materials due to pre-analysis acid preparation methods[J]. Chemical Geology, 2011, 282: 67−83. doi: 10.1016/j.chemgeo.2011.01.007
[47]	陈立雷, 张媛媛, 贺行良, 等. 海洋沉积物有机碳和稳定氮同位素分析的前处理影响[J]. 沉积学报, 2014, 32(6): 1046−1051. doi: 10.14027/j.cnki.cjxb.2014.06.006 Chen L L, Zhang Y Y, He X L, et al. The research on sample-pretreatment of organic carbon and stable nitrogen isotopes in marine sediments[J]. Acta Sedimentologica Sinica, 2014, 32(6): 1046−1051. doi: 10.14027/j.cnki.cjxb.2014.06.006
[48]	谭扬, 吴学丽, 侯立杰. 样品处理方法对海洋沉积物有机碳稳定同位素测定的影响[J]. 海洋环境科学, 2018, 37(5): 780−784. Tan Y, Wu X L, Hou L J, et al. The effects of sample treatment methods on marine sediment organic carbon stable isotope[J]. Maine Environmental Science, 2018, 37(5): 780−784.
[49]	周平, 徐国盛, 崔恒远, 等. 沉积岩中总有机碳测定前的预处理方法[J]. 实验室研究与探索, 2019, 38(1): 45−48. Zhou P, Xu G S, Cui H Y, et al. Study on pretreatment method of total organic carbon before determination in sedimentary rock[J]. Research and Exploration in Laboratory, 2019, 38(1): 45−48.
[50]	常文博, 李凤, 张媛媛, 等. 元素分析-同位素比值质谱法测量海洋沉积物中有机碳和氮稳定同位素组成的实验室间比对研究[J]. 岩矿测试, 2020, 39(4): 535−545. Chang W B, Li F, Zhang Y Y, et al. Inter-laboratory comparison of measuring organic carbon and stable nitrogen isotopes in marine sediments by elemental analysis-isotope ratio mass spectrometry[J]. Rock and Mineral Analysis, 2020, 39(4): 535−545.
[51]	Stüeken E E, Prave A R. Diagenetic nutrient supplies to the Proterozoic biosphere archived in divergent nitrogen isotopic ratios between kerogen and silicate minerals[J]. Geobiology, 2022, 20(5): 623−633. doi: 10.1111/gbi.12507
[52]	Boocock T J, Mikhail S, Prytilak J, et al. Nitrogen mass fraction and stable isotope ratios for fourteen geological reference materials: Evaluating the applicability of elemental analyser versus sealed tube combustion methods[J]. Geostandards and Geoanalytical Research, 2020, 44: 537−551. doi: 10.1111/ggr.12345
[53]	帅琴, 黄瑞成, 高强, 等. 页岩气实验测试技术现状与研究进展[J]. 岩矿测试, 2012, 31(6): 931−938. Shuai Q, Huang R C, Gao Q, et al. Research development of analytical techniques for shale gas[J]. Rock and Mineral Analysis, 2012, 31(6): 931−938.
[54]	Kang D L, Wang X H, Zheng X J, et al. Predicting the components and types of kerogen in shale by combining machine learning with NMR spectra[J]. Fuel, 2021, 290: 120006. doi: 10.1016/j.fuel.2020.120006
[55]	Wang Q, Liu Q, Wang Z C, et al. Characterization of organic nitrogen and sulfur in the oil shale kerogens[J]. Fuel Processing Technology, 2017, 160: 170−177. doi: 10.1016/j.fuproc.2017.02.031
[56]	Li L, Li K, Li Y Z, et al. Recommendations on offline combustion-based nitrogen isotopic analysis of silicate minerals and rocks[J]. Rapid Communications in Mass Spectrometry, 2021, 35: e9075.

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Nitrogen Isotope Analysis Method of Organic-enriched Shale

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