Spektrometria masowa i analiza izotopowa biomarkerów frakcji nasyconej

GC-IRMS analysis extends and confirms (or not) the interpretation based on the results of GC-MS analyses. For example, it is very useful in determining the sedimentation environment of organic matter. GC-MS analysis of biomarkers and the results are reliable, but only GC-IRMS studies can confirm it. In this study, the origin of BNH (28,30-bisnorhopane from chemoautotrophic bacteria) and origin of higher carotenoids and their derivatives from Chlorobiaceae or Chromotiaceae bacteria were confirmed through isotopic analyzes. Biomarkers were analyzed using the GC-IRMS and EA-IRMS apparatus. The obtained chromatograms from the IRMS analyses were compared with the archival GC-MS analyses for the same samples in order to identify individual chemical compounds. In addition to the existing methodology of sample preparation for analyses, a non-standard method was also used, consisting in the separation of n-alkanes from branched hydrocarbons. The repeatability of the method was determined on the GC-IRMS and the values of δ13C for selected biomarkers from the saturated fraction were determined. It was found that samples with low biomarker content are not suitable for analysis. On the other hand, too high concentration of the analyte causes an increase of the chromatogram baseline and worse separation of the peaks, which is also a problem. For the crude oils the δ13C values were initially determined for the biomarkers of the saturated fraction from the hopanes group: bisnorhopane (BNH), oleanane, C29 norhopane, C30 hopane, moretane and the C31-C35 homohopane series. Relatively small differences in δ13C values were found between BNH/hopanes and BNH/crude oils, which suggests the same source of origin for all biomarkers (including BNH). Determining biomarkers in the aromatic fraction using the GC-IRMS method was not successful. In the future, a special methodology for preparing samples for carbon isotopic analyses of aromatic fraction will be required.

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OXYGEN AND CARBON ISOTOPIC ANALYSES OF THE CARBONATE-HOSTED BORNITE CU-CO DEPOSIT, NW ALASKA

10.1130/abs/2019ne-328421 ◽

2019 ◽

Author(s):

Steven Surrusco ◽

◽

Christian M. Schrader ◽

Andrew West ◽

Bonnie Broman

Keyword(s):

Carbon Isotopic ◽

Isotopic Analyses

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Origin of atmospheric polycyclic aromatic hydrocarbons (PAHs) in Chinese cities solved by compound-specific stable carbon isotopic analyses

Organic Geochemistry ◽

10.1016/s0146-6380(02)00180-8 ◽

2002 ◽

Vol 33 (12) ◽

pp. 1737-1745 ◽

Cited By ~ 51

Author(s):

Tomoaki Okuda ◽

Hidetoshi Kumata ◽

Hiroshi Naraoka ◽

Hideshige Takada

Keyword(s):

Polycyclic Aromatic Hydrocarbons ◽

Aromatic Hydrocarbons ◽

Stable Carbon ◽

Chinese Cities ◽

Carbon Isotopic ◽

Isotopic Analyses ◽

Polycyclic Aromatic

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Determination of the stable carbon isotopic compositions of 2-methyltetrols for four forest areas in Southwest China: The implications for the δ13C values of atmospheric isoprene and C3/C4 vegetation distribution

The Science of The Total Environment ◽

10.1016/j.scitotenv.2019.04.432 ◽

2019 ◽

Vol 678 ◽

pp. 780-792

Author(s):

Li Li ◽

Yi Zhou ◽

Xinhui Bi ◽

Shihuai Deng ◽

Shuxiao Wang ◽

...

Keyword(s):

Southwest China ◽

Vegetation Distribution ◽

Stable Carbon ◽

Δ13c Values ◽

Isotopic Compositions ◽

Carbon Isotopic

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Chemical composition and stable carbon isotopic ratios of crude oils from Southern Germany

Organic Geochemistry ◽

10.1016/0146-6380(80)90019-4 ◽

1980 ◽

Vol 2 (1) ◽

pp. 45-53 ◽

Cited By ~ 10

Author(s):

Paula Hahn-Weinheimer ◽

Alfred Hirner

Keyword(s):

Chemical Composition ◽

Crude Oils ◽

Isotopic Ratios ◽

Stable Carbon ◽

Southern Germany ◽

Carbon Isotopic

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The use of stable carbon isotope trends as a correlation tool: an example from the Surat Basin, Australia

The APPEA Journal ◽

10.1071/aj15026 ◽

2016 ◽

Vol 56 (1) ◽

pp. 355 ◽

Cited By ~ 1

Author(s):

Astrid Hentschel ◽

Joan S. Esterle ◽

Sue Golding

Keyword(s):

Carbon Isotope ◽

Turning Point ◽

Stable Carbon Isotope ◽

Stable Carbon ◽

Δ13c Values ◽

Carbon Isotopic ◽

Gas Source ◽

Rapid Reversal ◽

Allogenic Processes ◽

Coal Measures

The Surat Basin’s Middle Jurassic Walloon Subgroup is a productive coal seam gas source in Queensland, Australia. The Walloon Subgroup can be subdivided into the Upper and Lower Juandah coal measures, the Tangalooma Sandstone, the Taroom Coal Measures, and the Eurombah/Durabilla Formation, from top to bottom. Correlation across the basin is challenging due to high lateral variability and lack of extensive stratigraphic markers. The Walloon Subgroup is also, in places, incised by the overlying Springbok Sandstone, sometimes interpreted as far down as the Tangalooma Sandstone. New age dates suggest that the Walloon Coal Measures are Oxfordian in age and mark a period of high rates of Corg production and burial, and an intermittent decrease of atmospheric pCO2. The un- or dis-conformable base of the Springbok Sandstone coincides with a turning point of this supposedly global phenomenon. This study uses organic stable carbon isotope trends as a correlation tool within the Surat Basin’s Walloon Subgroup and its overlying Springbok Sandstone. Analysis of a stratigraphic suite of coal samples from several wells across the Surat Basin shows a gradual enrichment in 13C up section from the Taroom to the Lower Juandah Coal Measures, with the most positive δ13C values within the Upper Juandah Coal Measures. Thereafter there is a rapid reversal to more negative δ13C values for coal samples of the Springbok Sandstone. The upward enrichment occurs well before the shift in maceral composition to increased inertinite content in the coals, suggesting more global allogenic processes are controlling the carbon isotopic trend. The consistency of these trends lends a more confident correlation for sub-units within the Walloon Subgroup, and assists in determining the level of incision disconformity of the Springbok Sandstone.

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Carbon isotopic composition of branched tetraether membrane lipids in soils suggest a rapid turnover and a heterotrophic life style of their source organism(s)

Biogeosciences ◽

10.5194/bg-7-2959-2010 ◽

2010 ◽

Vol 7 (9) ◽

pp. 2959-2973 ◽

Cited By ~ 106

Author(s):

J. W. H. Weijers ◽

G. L. B. Wiesenberg ◽

R. Bol ◽

E. C. Hopmans ◽

R. D. Pancost

Keyword(s):

Organic Carbon ◽

Isotopic Composition ◽

Life Style ◽

Membrane Lipids ◽

Carbon Isotopic Composition ◽

Turnover Time ◽

Arable Soils ◽

Higher Plant ◽

Δ13c Values ◽

Carbon Isotopic

Abstract. Branched Glycerol Dialkyl Glycerol Tetraethers (GDGTs) are membrane spanning lipids synthesised by as yet unknown bacteria that thrive in soils and peat. In order to obtain more information on their ecological niche, the stable carbon isotopic composition of branched GDGT-derived alkanes, obtained upon ether bond cleavage, has been determined in a peat and various soils, i.e. forest, grassland and cropland, covered by various vegetation types, i.e., C3- vs. C4-plant type. These δ13C values are compared with those of bulk organic matter and higher plant derived n-alkanes from the same soils. With average δ13C values of −28‰, branched GDGTs in C3 soils are only slightly depleted (ca. 1‰) relative to bulk organic carbon and on average 8.5‰ enriched relative to plant wax-derived long-chain n-alkanes ( nC29–nC33). In an Australian soil dominantly covered with C4 type vegetation, the branched GDGTs have a δ13C value of −18‰, clearly higher than observed in soils with C3 type vegetation. As with C3 vegetated soils, branched GDGT δ13C values are slightly depleted (1‰) relative to bulk organic carbon and enriched (ca. 5‰) relative to n-alkanes in this soil. The δ13C values of branched GDGT lipids being similar to bulk organic carbon and their co-variation with those of bulk organic carbon and plant waxes, suggest a heterotrophic life style and assimilation of relatively heavy and likely labile substrates for the as yet unknown soil bacteria that synthesise the branched GDGT lipids. However, a chemoautotrophic lifestyle, i.e. consuming respired CO2, could not be fully excluded based on these data alone. Based on a natural labelling experiment of a C3/C4 crop change introduced on one of the soils 23 years before sampling and based on a free-air CO2 enrichment experiment with labelled CO2 on another soil, a turnover time of ca. 18 years has been estimated for branched GDGTs in these arable soils.

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