Characterisation of the unresolved complex mixture (UCM) in the gas chromatograms of biodegraded petroleums

Killops, S. D.; Al-Juboori, M.A.H.A.

doi:10.1016/0146-6380(90)90079-f

Cited by 133 publications

(69 citation statements)

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“…UCMs are frequently observed in petroleums and hydrocarbon (HC) extracts that have undergone biodegradation (Rowland and Maxwell, 1984;Killops and Al-Juboori, 1990;Gough and Rowland, 1990;Frysinger et al, 2003) or hydrothermal alteration (Rushdi and Simoneit 2002;Simoneit et al, 2004;Zárate-del Valle and Simoneit, 2005). UCMs of biodegraded oils typically contain a low abundance or complete absence, of aliphatic compounds (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…Connan, 1984;Rowland et al, 1986;Palmer, 1993;Swannell et al, 1995;Bost et al, 2001;Reddy et al, 2002). The removal of these constituents, which averages 32% of the total hydrocarbon composition of most crude oils (Killops and Killops, 2005) concentrates a preexisting complex mixture to yield the amplified chromatographic baseline of a UCM (Killops and Al-Juboori, 1990). …”

Section: Introductionmentioning

confidence: 99%

“…Attempts to identify the constituents in UCMs have met with varying degrees of success and involved chemical oxidation (Gough and Rowland, 1990;Killops and Al-Juboori, 1990;Revill et al, 1992;Warton, 1999;Warton et al, 2000), thin layer chromatography (Liu et al, 2005), chemical oxidation followed by treatment with molecular sieves (e.g. Armanios et al, 1994;Ellis et al, 1994;Fazeelat et al, 1994), statistical deconvolution methods (Pool et al, 1997;Dagan 2000;Demir et al, 2000) and field ionization mass spectrometry (Payzant et al, 1979).…”

Section: Introductionmentioning

confidence: 99%

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Analysis of unresolved complex mixtures of hydrocarbons extracted from Late Archean sediments by comprehensive two-dimensional gas chromatography (GC×GC)

Ventura

Kenig

Reddy

et al. 2008

Organic Geochemistry

116

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Hydrocarbon mixtures too complex to resolve by traditional capillary gas chromatrography display gas chromatograms with dramatically rising baselines or "humps" of coeluting compounds that are termed unresolved complex mixtures (UCMs). Because the constituents of UCMs are not ordinarily identified, a large amount of geochemical information is never explored. Gas chromatograms of saturated/unsaturated hydrocarbons extracted from Late Archean argillites and greywackes of the southern Abitibi Province of Ontario, Canada contain UCMs with different appearances or "topologies" relating to the intensity and retention time of the compounds comprising the UCMs. These topologies appear to have some level of stratigraphic organization, such that samples collected at any stratigraphic formation collectively are dominated by UCMs that either elute early-(within a window of C 15 -C 20 of n-alkanes), earlyto mid-(C 15 -C 30 of n-alkanes), or have a broad UCM that extends through the entire retention time of the sample (from C 15 -C 42 of n-alkanes). Comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-MS) was used to resolve the constituents forming these various UCMs. Early-to mid-eluting UCMs are dominated by configurational isomers of alkyl-substituted and non substituted polycyclic compounds that contain up to six rings. Late eluting UCMs are composed of C 36 -C 40 mono-, bi-, and tricyclic archaeal isoprenoid diastereomers. Broad UCMs spanning the retention time of compound elution contain nearly the same compounds observed in the early-, mid-, and late retention time UCMs. Although the origin of the polycyclic compounds is unclear, the variations in the UCM topology appear to depend on the concentration of initial compound classes that have the potential to become isomerized. Isomerization of these constituents may have resulted from hydrothermal alteration of organic matter.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Analysis of unresolved complex mixtures of hydrocarbons extracted from Late Archean sediments by comprehensive two-dimensional gas chromatography (GC×GC)

Ventura

Kenig

Reddy

et al. 2008

Organic Geochemistry

116

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“…There is a significant balance among the abundance of n-alkanes with even and odd carbon atoms and also a «hump» or unresolved complex mixture (UCM) extending over much of the range occupied by n-alkanes. This can be interpreted as a mature, old, oil-source rack where n-alkanes have cracked over time (Killops and Al-Juboori, 1990). …”

Section: Organic Geochemistrymentioning

confidence: 99%

Untitled

Torres¹,

Ortíz²,

Cobo³

2003

Estud. geol.

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We analyse how physical and chemical deep-cave sediment features preserve the morphological and geochemical characteristics of paleontological materials. Detrital sediment chemistry and clast size are fundamental because they provide a soft, impervious and plastic environment in which fossil remains are transported with minimal erosion. Sediment mineralogy provides a carbonate-and phosphate-buffered environment in which molecules of biological origin hydrolyze slower than in open-air environments or even at cave entrance sites. Because permafrost did not develop in the Iberian Peninsula (at least at the altitudes of inhabited caves), sediment desiccation never took place. In addition, sediment -pores were not aerated, which protected fossil remains from air (oxygen)-linked weathering. The annual-temperature variation inside sediment was negligible, which contributed to amino acid racemization dating. Collagen amino acid and amino acid racemization analysis of cave bear and man samples from cave sediments dated from different Oxygen Isotope Stages (4 th : Sidrón, Amutxate, Troskaeta, El Toll, Coro Tracito, Ekain, Lezetxiki, La Pasada, Eirós; 5 th : Reguerillo and Arrikrutz; 6 th _7 th : Sima de los Huesos) demonstrate that important amounts of almost intact collagen still remain in teeth dentine. Fossil DNA search seems to be very promising.Key words: Taphonomy, karst sedimentology, inorganic geochemistry, organic geochemistry, temperature variation, dentine, collagen, aspartic acid, racemization. RESUMENEn este trabajo se analiza el papel que juegan las características físicas y químicas de los sedimentos de galerías profundas de cuevas en la preservación de los caracteres morfológicos y paleobiomoleculares del material paleontológico incluido en dichos sedimentos. Los aspectos geoquímicos y de tamaño de grano del sedimento son críticos: las características generan un medio blando, plástico e impermeable que permite el transporte -mecánico sin grave deterioro del material (en coladas de barro); las características quí-micas mineralogía del sedimento--proporcionan un ambiente con tampón fosfatado-carbonatado en el cual las biomoléculas hidrolizarán a un ritmo mucho más pausado que como lo harían al aire libre o en la entrada de las cavidades. Dado que el permafrost no fue un fenómeno extendido en la Península Ibérica durante al Cuaternario, al menos en las cotas a las que se situaban las cuevas habitadas por osos u hombres, nunca se produjo la desecación del sedimento y los poros no se llenaron de aire, protegiéndose los restos fósi-les de la meteorización. Se ha registrado el cambio anual de temperatura dentro del sedimento y éste es prácticamente inapreciable, lo que añade nuevo interés a la fiabilidad del método de datación por racemización de aminoácidos. El análisis del colágeno remanente en la dentina de dientes de osos y hombres y de la racemización del ácido aspártico como herramienta geocronológica en material proveniente de sedimentos datados en diferentes Estadios Isotópicos del Oxígeno (4.°: S...

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“…Based on the nature of the hydrocarbons (HC), crude oil can be classified into three groups: (i) paraffin-based crude oils; (ii) asphaltic-base crude oils and (iii) mixed-base crude oils (Cleveland 2007). Additionally, petroleum contains a complex mixture of compounds which can be categorized into four fractions: saturates, aromatics, resins and asphaltenes (Killops andAl-Jaboori 1990, Outdot et al 1998).…”

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confidence: 99%

Effect of N and P fertilisation and aeration on biodegradation of crude oil in aged hydrocarbon contaminated soils

Syafruddin¹,

Wieshammer²,

Puschenreiter³

et al. 2010

PLANT SOIL ENVIRON

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We conducted two laboratory experiments to examine the effects of fertilisation and agitation (aeration) on crude oil degradation in two soils with differential nutrient (nitrogen, phosphorus) availability. Two soils that had been spiked with crude oil two years before were mixed with nitrogen and/or phosphorus at three different levels and subsequently incubated 28 days (Exp. 1). In experiment 2 we investigated the effect of repeated agitation (manual mixing) on hydrocarbon degradation with and without fertilisation. One of the soils was also freshly spiked to assess the impact of ageing. Heptane-extractable hydrocarbon concentrations were determined in both experiments and substrate-induced respiration in Exp. 2. The generally small changes of hydrocarbon concentrations during 28 days of incubation in Exp. 1 are likely attributed to low bio-accessibility of hydrocarbons as a consequence of longterm ageing. Fertilization of nitrogen, phosphorus or combinations thereof was ineffective in most treatments of Exp. 1, which may be explained by limited oxygen supply due to the high proportions of clay and silt. However, agitation enhanced HC biodegradation in the sandy-loamy soil by about 15% (Exp. 2) compared to non-agitated treatments. In contrast, we observed no effect of agitation in the sandy soil.

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Characterisation of the unresolved complex mixture (UCM) in the gas chromatograms of biodegraded petroleums

Cited by 133 publications

References 14 publications

Analysis of unresolved complex mixtures of hydrocarbons extracted from Late Archean sediments by comprehensive two-dimensional gas chromatography (GC×GC)

Analysis of unresolved complex mixtures of hydrocarbons extracted from Late Archean sediments by comprehensive two-dimensional gas chromatography (GC×GC)

Untitled

Effect of N and P fertilisation and aeration on biodegradation of crude oil in aged hydrocarbon contaminated soils

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