著者

Satoshi Sugaya Yuko Takizawa Yoshito Chikaraishi

出版者

The Japanese Association of Organic Geochemists

雑誌

Researches in Organic Geochemistry (ISSN:13449915)

巻号頁・発行日

vol.38, no.1, pp.13-18, 2022-12-27 (Released:2023-03-15)

参考文献数

14

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Trophic position (TP) estimates of organisms using compound-specific isotope analysis (CSIA) of nitrogen within amino acids allow us to trace the trophic transfer of organic materials in food webs and its dynamics in biogeochemical cycles. However, accuracy of the estimates is potentially affected by natural variation in the body size within a species, because the isotope ratios of amino acids primarily correlate with metabolic activities in organisms. In the present study, we therefore determined the δ15N values of amino acids for two species of juvenile fish (the cresthead flounder Pleuronectes schrenki and the sunrise sculpin Pseudoblennius cottoides) that have a variation in the body size in a natural coastal marine environment, to evaluate the effects of body size on the TP values estimated for these juvenile fish. Because the juvenile fish investigated were a couple of months old and grew together in a natural coastal marine environment for each species, variation in the body size within species can be explained primarily by diet amounts and/or metabolic activities at the individuals. However, the results illustrate that variation in the TP value estimated is negligible (i.e., ±0.08 for cresthead flounder and ±0.05 for sunrise sculpin) even though there is a large variation in the body length within species (28-54 mm and 19-34 mm, respectively), and clearly indicate that the effects of body size are negligible to the δ15N values of amino acids and associated TP estimates at least for juvenile fish of two species investigated. These results will be useful for reducing the sample size of CSIA and for expanding application in further trophic food web studies, as well as for better understanding the factors controlling for natural variation in the body size within a species.

著者

Kota Yamamoto Yuko Takizawa Yoshito Chikaraishi

出版者

The Japanese Association of Organic Geochemists

雑誌

Researches in Organic Geochemistry (ISSN:13449915)

巻号頁・発行日

vol.38, no.1, pp.7-12, 2022-12-27 (Released:2023-03-15)

参考文献数

20

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Difference in the stable nitrogen isotope ratio (δ15N value) between two types of amino acids within a single organism has been employed as a powerful tool for estimating the trophic position (TP) of the organism in food webs. However, accuracy of the TP values estimated relies on the consistency of trophic elevation in the δ15N value across diverse organisms and among diverse environments. Indeed, little is known the applicability of this tool for organisms found in cold environments. In the present study, we determined the δ15N values of amino acids for 10 species collected in a coastal marine environment of Hokkaido, a humid continental climate zone in Japan, to evaluate whether this tool is applicable to marine species found in cold regions. The δ15N values of glutamic acid and phenylalanine determined in the present study illustrate diverse TP values for the species, as 0.7-1.0 for primary producers (i.e., macroalgae), 1.9-2.3 for herbivores (e.g., zooplankton and sea urchin), and 2.3-3.7 for omnivores and carnivores (e.g., crab and fish). These results indicate that the TP values estimated in the present study are basically consistent with actual TP for producers and herbivores and with the literature TP values for the same or similar species of omnivores and carnivores from temperate regions, and thus provide evidence that this tool is basically applicable to estimate the TP of marine species found in cold regions. On the other hand, low TP value was estimated for one species, goby, suggesting that further studies will be required, particularly for identifying mechanisms responsible for the low TP values estimated for such species.

著者

Michiru Kanaya Yuko Takizawa Yoshito Chikaraishi

出版者

The Japanese Association of Organic Geochemists

雑誌

Researches in Organic Geochemistry (ISSN:13449915)

巻号頁・発行日

vol.38, no.1, pp.1-6, 2022-12-27 (Released:2023-03-15)

参考文献数

11

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Compound-specific isotope analysis (CSIA) of organic compounds with a gas chromatograph - isotope ratio mass spectrometer (GC-IRMS) has been employed as one of the most powerful techniques in molecular isotope studies. This analysis is applicable not only for volatile and non-polar compounds (e.g., hydrocarbons), but also for non-volatile and polar compounds (e.g., alcohols and fatty acids) when such low volatility and high-polarity are reduced by derivatization. However, derivatization frequently causes isotopic fractionation, which considerably reduces the accuracy on the isotope ratios determined. In the present study, we investigated change in the carbon isotope ratio (δ13C value) of 1-hexadecanol that acetylated with a variable molar balance between substrate and derivative reagent, to illustrate the fractionation of carbon isotopes during acetylation of alcohols. The results illustrate that the δ13C values of acetyl group of the 1-hexadecanol derivative asymptotically change from −38.8‰ to −60.8‰, with the molar balance decreasing from 1:10 to 1:30000 in the acetylation. Moreover, the isotopic fractionation factor (α) calculated is 0.9711 if the Rayleigh fractionation model is applied. Thus, we demonstrated that there is a large fractionation of carbon isotopes in the acetylation of alcohols, and that the degree of fractionation is correlated with the molar balance between substrate and derivative reagent of the acetylation.

著者

力石 嘉人 高野 淑識 小川 奈々子 佐々木 瑶子 土屋 正史 大河内 直彦

出版者

日本有機地球化学会

雑誌

Researches in Organic Geochemistry (ISSN:13449915)

巻号頁・発行日

vol.27, pp.3-11, 2011-09-30 (Released:2017-04-13)

参考文献数

30

被引用文献数

1

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Recent evidences have suggested that compound-specific stable isotope analysis (CSIA) of amino acids has been employed as a new powerful method with that enables the estimation of trophic level of organisms in not only aquatic but also terrestrial food webs. This CSIA approach is based on contrasting the 15N-enrichment with each trophic level between two common amino acids: glutamic acid shows significant enrichment of +8.0‰ with each trophic level, whereas phenylalanine shows little enrichment of +0.4‰. These 15N-enrichments are well consistent in both aquatic and terrestrial organisms. The trophic level of organisms can be estimated within a small error as 1σ=0.12 for aquatic and 0.17 for terrestrial food webs, employing the eq.: [Trophic level]=(δ15Nglutamic acid-δ15Nphenylalanine+β)/7.6+1, where β represents the isotopic difference between these two amino acids in primary producers (-3.4‰ for aquatic cyanobacteria and algae, +8.4‰ for terrestrial C3 higher plants, and -0.4‰ for terrestrial C4 higher plants). Here, we briefly review this new method (i.e. CSIA of amino acids) and its application to natural organisms in terrestrial environments.

著者

河村 公隆 山崎 正夫 石渡 良志

出版者

日本有機地球化学会

雑誌

Researches in organic geochemistry (ISSN:13449915)

巻号頁・発行日

vol.2, pp.30-36, 1978-09

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1.榛名湖,琵琶湖表層堆積物中にC_<18:2>,C_<18:3α>を含む不飽和脂肪酸を検出した。2.しかしその深度分布は二つの湖で大きく異なる。榛名湖では不飽和酸は飽和酸に対して深さとともに急速に減少するが,琵琶湖では大きな変化は観察されなかった。この差異の原因の一つとして堆積物の質的差異があげられる。3.琵琶湖の場合,5mまでの深さにおいてもC_<18:2>,C_<18:3>ポリ不飽和酸を検出した。それらは,0.2,2,3.5m附近で大きな濃度値を示した。これはポリオ飽和酸の供給量の変動によるものと解釈される。ポリ不飽和酸の供給量は当時の湖の水温,気温の変動を反映している可能性がある。

著者

山本 正伸

出版者

日本有機地球化学会

雑誌

Researches in Organic Geochemistry (ISSN:13449915)

巻号頁・発行日

vol.39, no.1, pp.1-12, 2023-07-14 (Released:2023-09-12)

参考文献数

40

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Atmospheric carbon dioxide (CO2) is an essential factor in determining the Earth's climate. In predicting future warming, it is necessary to understand how atmospheric CO2 has affected past climate change. Past atmosphericCO2 concentrations have been determined by analyzing gases in ice cores drilled through the Antarctic ice. In this study, we show that the carbon isotope ratios of plant-derived fatty acids in the Bay of Bengal sediments represent past atmospheric CO2 concentration changes by comparing them with those in ice cores. Using this relationship, we have shown for the first time that atmospheric CO2 concentration changes before ca 800,000 years ago can be determined with high precision and high temporal resolution. The results show that even before ca 800,000 years ago, the CO2 concentration fluctuated almost synchronously with the volume of continental ice sheets. However, the CO2 concentrations were unexpectedly not high during the warm period prior to 1 million years ago. It was also found that the CO2 concentrations fluctuated earlier than the volumes of continental ice sheets before 1 million years ago but later than the ice volumes after ca 800,000 years ago.

著者

長谷川 卓

出版者

日本有機地球化学会

雑誌

Researches in Organic Geochemistry (ISSN:13449915)

巻号頁・発行日

vol.23.24, pp.43-52, 2008-12-30 (Released:2017-04-10)

参考文献数

41

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The Paleocene-Eocene thermal maximum (PETM) is marked by a large negative carbon isotope excursion (CIE) and massive seafloor carbonate dissolution. Both phenomena are thought to have been caused by a sudden release of a large mass of carbon. The step-like nature of the CIE onset combined with the CIE magnitude has been explained by multiple dissociation of methane clathrate as the primary source of carbon. The natures of onset and the magnitude of CIE, however, are different between marine and terrestrial records implying potential artifacts in either or both records. Recently, the carbon isotope stratigraphy based on various techniques including compound-specific isotope analysis on terrestrial and marine biomarkers, single specimen analysis on surface-dwelling planktonic foraminifera revealed that 'actual' CIE is as large as 4‰ or larger, and the onset of the CIE was geologically instantaneous. These results demonstrated that the CIE magnitude (2-3‰) previously applied to estimate the mass of carbon released during the PETM was considerably underestimated and that abrupt input of 13C-depleted carbon to the ocean-atmosphere system. Forthcoming high-resolution studies on the PETM with precise inter-regional correlation would provide a unique opportunity for comparative research of global warming between PETM period and the present.

著者

山本 修一 近藤 寛 石渡 良志 上村 仁

出版者

日本有機地球化学会

雑誌

Researches in Organic Geochemistry (ISSN:13449915)

巻号頁・発行日

vol.31, no.2, pp.51-68, 2015-12-30 (Released:2016-11-07)

参考文献数

27

被引用文献数

1

著者

Kazuo Fukushima Mina Kato Saeko Takamatsu Yusuke Shiraki Arata Yoda

出版者

The Japanese Association of Organic Geochemists

雑誌

Researches in Organic Geochemistry (ISSN:13449915)

巻号頁・発行日

vol.37, no.2, pp.45-58, 2021-12-30 (Released:2022-06-09)

参考文献数

35

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A short surface sediment core (40cm) was collected from a strongly acidic (pH=2.2) freshwater lake, Katanuma, Miyagi Prefecture, Japan. Lake Katanuma is a maar, the water of which is rich in sulfate, sulfides and free sulfur and is located in the active Naruko geothermal field. Lipid compounds in the uppermost sediment were extracted and analyzed for organosulfur compounds (OSCs) by gas chromatography (GC) and gas chromatograph-mass spectrometry (GC-MS). The OSCs identified in the lake sediment were C13-C20 3-methyl- and 3-ethyl-5-alkyl thiophenes, C35 hopanoid thiophenes and C18 thiophene carboxylic acids (TCAs), in addition to C20 isoprenoid thiophenes. In the present work, production of C18 TCAs was examined by a mild laboratory simulation reaction of reagent grade linoleic acid (cis, cis-9,12-octadecadienoic acid: C18:2) as well as the solvent extracts from the lake sediments, in H2S saturated water. We confirmed that the C18 TCAs could be in fact produced under the simple experimental system. However, the abundances of the C18 TCAs detected were too small compared with those of possible precursors, C18:2 acids, which is ubiquitous in the particulate matter in the Lake Katanuma water, but almost completely disappeared in subsurface sediment. This finding suggests that sulfur plays a role in a very early stage of diagenesis for sequestering chemically reactive lipid molecules by transforming them into complex geopolymers rather than into small OSCs. No apparent variations in concentration of those OSCs were observed downwards the sediment core. The immediate precursors of alkylthiophenes and hopanoid thiophenes remain to be unraveled.

著者

熊田 英峰 高田 秀重 ザカリア モハマド パウジ

出版者

日本有機地球化学会

雑誌

Researches in Organic Geochemistry (ISSN:13449915)

巻号頁・発行日

vol.15, pp.13-25, 2000

参考文献数

35

被引用文献数

3

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In order to investigate chemical fingerprints of different combustion sources, polycyclic aromatic hydrocarbons (PAHs) of airborne particulate samples were collected on three different occasions in Beijing (China), Tokyo (Japan) and Malaysia. Total-PAHs concentrations, including methyl- and dimethylphenanthrenes and sulfur containing hetero-aromatics (PASHs), were found to be the highest in Beijing (winter) samples followed by Beijing (summer), Tokyo, and Malaysia with readings of (405, 437), (20.4, 41.1), (8.43-43.1), and (2.64-42.6)ng/m³, respectively. Some of compositional differences observed could be due to the difference in combustion sources among the three countries rather than environmental alterations. Using ratios of benzo[ghi]perylene to benzo [e] pyrene (BghiP/BeP) and dimethylphenanthrenes to fluoranthene (DMP/Flu), Malaysian aerosols were elucidated from Tokyo and Beijing samples, suggesting high BghiP/BeP and DMP/Flu ratios as potential molecular markers of biomass-burning in the tropical region. Retene and 1,7-DMP/2,6-DMP ratio had previously been suggested as molecular markers for wood- or conifer-burning, were found to be useless in tropical region. Although PASHs were expected as molecular markers for the burning of sulfur-rich coal in China, ratios of PASHs to total-PAHs had showed only a slight enrichment in Beijing (winter) samples which was significantly affected by coal-combustion as compared to other samples in this study.

著者

荻原 成騎

出版者

日本有機地球化学会

雑誌

Researches in Organic Geochemistry (ISSN:13449915)

巻号頁・発行日

vol.27, pp.149-154, 2011-09-30 (Released:2017-04-13)

参考文献数

6

著者

中村 英人 沢田 健

出版者

日本有機地球化学会

雑誌

Researches in Organic Geochemistry (ISSN:13449915)

巻号頁・発行日

vol.22, pp.31-42, 2007

参考文献数

16

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The chemical compositions of woody fossil fragments collected by picking manually and density centrifugation from sandstones of the Lower Cretaceous Yezo Group in Oyubari, central Hokkaido, Japan were analyzed by KOH/methanol hydrolysis (saponification) after solvent extraction. Organic compounds bound in macromolecules of the woody fragments with ester bonds, obtained by saponification, were mainly composed of short-chain (C₁₄ to C₁₈) fatty acids and series of <i>n</i>-alkanols ranging from C₁₂ to C₂₈ homologues. These ester bound constituents are attributed to moieties of polyester parts of selectively preserved resistant macromolecule like cutin or suberin. Even carbon-number predominance was observed in both compounds, which indicated that biological components were well preserved. The bound fatty acids showed similar distribution patterns among all samples, indicating that these moieties might have been altered by strong diagenetic processes. On the other hand, the distribution patterns of <i>n</i>-alkanols significantly varied. In particular, those of long-chain (>C₂₀) <i>n</i>-alkanols varied possibly depending on plant taxonomy. Thus, we suggest that these parameters are strongly useful as molecular paleobiological indicators for chemotaxonomic analyses. Also, the distributions of short-chain <i>n</i>-alkanols and the ratios of short to long-chain homologues are presumably useful indicators for diagenesis, taphonomy and environment.

著者

齊藤 諒介

出版者

日本有機地球化学会

雑誌

Researches in Organic Geochemistry (ISSN:13449915)

巻号頁・発行日

vol.32, no.2, pp.19-53, 2016

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<p>The mass extinction at the end of Permian was the severest crisis in the Earth's history. Oceanic euxinia and acidification as well as global warming all have been hypothesized as causes for the mass extinction. However, oceanic euxinia occurred much earlier than the mass extinction, and oceanic acidification and global warming postdated. Accordingly, the cause for the end-Permian mass extinction is not fully understood. Organic geochemical studies have been the most extensively performed for the mass extinction event, and revealed important findings such as soil erosion, photic zone euxinia, and proliferation of cyanobacteria for the event. Recovery from the mass extinction was much delayed and took place in the Middle Triassic, after 5 million years from the mass extinction. Subsequently, the Early Triassic period is the transition interval from the mass extinction to the recovery. The environments in the Early Triassic were rather instable, and another mass extinctions and recoveries repeatedly occurred. Organic geochemical studies have suggested photic zone euxinia, stressful environments, and an occurrence of a previously undiscovered type of microbialite during the Early Triassic. In the present paper, I introduce the evidences of environmental and biotic changes through the end-Permian mass extinction to the Early Triassic.</p>

著者

藤 加珠子 村江 達士 北島 富美雄

出版者

日本有機地球化学会

雑誌

Researches in organic geochemistry (ISSN:13449915)

巻号頁・発行日

vol.12, pp.21-26, 1997-05-30

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Some type of macerals in sediments fluoresces under ultraviolet light. According to an increase of their maturity level, the wavelength of fluorescence maximum sifts toward longer wavelength, and intensity of the fluorescence diminishes. This property allows the fluorescence spectra to be a good maturity indicator for low immature sediment samples whose maturity can be hardly determined by vitrinite reflectance. However, correlations between thermal alteration of the fluorescent substances and the "red-shift" in the spectra are not clarified well. In this investigation, we examined thermal alteration of fluorescence spectra and chemical structures of fluorescent substances in the resinite from Latrobe Valley (Victoria, Australia). The samples were heated stepwise from 100℃ to 320℃ at 20℃ intervals for 15min at each temprature. We observed fluorescence spectra and ultraviolet-visible (UV-VIS) absorption spectra of the samples cooled after maintaining for 15min at each temperature. The "red-shift" in the fluorescence spectra was associated with alterations of UV-VIS absorptions. The IR spectra of the original samples and of the samples obtained after heating at the final temperature were also determined. No IR absorption bands due to aromatic rings appeared after the heating. These facts indicated that elongations of conjugated double bonds caused the "red-shift" of fluorescence.

著者

長谷川 卓

出版者

日本有機地球化学会

雑誌

Researches in organic geochemistry (ISSN:13449915)

巻号頁・発行日

vol.23, pp.43-52, 2008-12-30

---

The Paleocene-Eocene thermal maximum (PETM) is marked by a large negative carbon isotope excursion (CIE) and massive seafloor carbonate dissolution. Both phenomena are thought to have been caused by a sudden release of a large mass of carbon. The step-like nature of the CIE onset combined with the CIE magnitude has been explained by multiple dissociation of methane clathrate as the primary source of carbon. The natures of onset and the magnitude of CIE, however, are different between marine and terrestrial records implying potential artifacts in either or both records. Recently, the carbon isotope stratigraphy based on various techniques including compound-specific isotope analysis on terrestrial and marine biomarkers, single specimen analysis on surface-dwelling planktonic foraminifera revealed that 'actual' CIE is as large as 4‰ or larger, and the onset of the CIE was geologically instantaneous. These results demonstrated that the CIE magnitude (2-3‰) previously applied to estimate the mass of carbon released during the PETM was considerably underestimated and that abrupt input of ^<13>C-depleted carbon to the ocean-atmosphere system. Forthcoming high-resolution studies on the PETM with precise inter-regional correlation would provide a unique opportunity for comparative research of global warming between PETM period and the present.