Structurally bound lipids in peat humic acids

Lehtonen, Keijo; Hänninen, Kari; Ketola, Martti

doi:10.1016/s0146-6380(00)00158-3

Cited by 39 publications

(26 citation statements)

References 48 publications

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“…These belong to the most common fatty acids in plant and animal lipids (Gobe et al, 2000) and are often detected in HA samples that have undergone pyrolysis (del Rio et al, 1998;Li et al, 2006). Unsaturated monocarboxylic acids, such as hexadecenoic acid and octadecenoic acid, also detected in all the samples, may have derived from vegetation emissions (Lehtonen et al, 2001). A high abundance of dicarboxylic acid methyl esters homologues was detected in all HULIS samples.…”

Section: Sample Functional Groups (%)mentioning

confidence: 95%

Comparative study for separation of atmospheric humic-like substance (HULIS) by ENVI-18, HLB, XAD-8 and DEAE sorbents: Elemental composition, FT-IR, 1H NMR and off-line thermochemolysis with tetramethylammonium hydroxide (TMAH)

2013

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Section: Sample Functional Groups (%)mentioning

confidence: 95%

Comparative study for separation of atmospheric humic-like substance (HULIS) by ENVI-18, HLB, XAD-8 and DEAE sorbents: Elemental composition, FT-IR, 1H NMR and off-line thermochemolysis with tetramethylammonium hydroxide (TMAH)

2013

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“…Despite various degradation processes, these diterpenoids are very stable in the geosphere and were reported from various sediments, coals, peats and fossil conifers (e.g., Chaffee Steroid degradation products: stigmastan-3-one + stigmasta-3,5-dyen-7-one + sitosterone. Simoneit 1986 and references therein; Simoneit et al 1986;Lehtonen et al 2001;Otto and Simoneit 2001). The preservation of the polar diterpenoids in geological samples is in part due to the protection of biomolecules against microbial and abiogenic degradation in the resinous material (Otto et al 2002).…”

Section: Degradation Vs Degradation Of Major Lipid Classesmentioning

confidence: 99%

Degradation and Preservation of Vascular Plant-derived Biomarkers in Grassland and Forest Soils from Western Canada

2005

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The total solvent extracts (TSE) of mineral and organic horizons of selected soils and overlying vegetation were analyzed using gas chromatography-mass spectrometry (GC-MS) to determine the composition of solvent-extractable ('free') lipids in soils and to study the degradation and possible preservation of vascular plant-derived molecular markers (biomarkers) in soils. Major compound classes in the TSE of soils and vegetation included a homologous series of aliphatic lipids (alkanoic acids, alkanols, alkanes), steroids, and terpenoids. Characteristic patterns of aliphatic and cyclic biomarkers derived from the overlying, native vegetation were recognized in the associated soil samples indicating the preservation of lipids from the external waxes of vascular plants in the soil organic matter (SOM). The observed biomarker patterns in the grassland soils (Brown Chernozems) were similar to the compounds identified in their major source vegetation, Western Wheatgrass. A similar composition of biomarkers was observed in Aspen leaves and the soil horizons of the forest-grassland transition soil (Dark Gray Chernozem). The Lodgepole Pine needles yielded a characteristic pattern of diterpenoids that was also detected in leaf litter and the O horizon of the associated forest soil (Brunisol). The results demonstrate that solvent extractable biomarkers derived from vascular plants maintain their characteristic pattern of aliphatic and cyclic lipids despite ongoing degradation processes and are thus valuable molecular markers for the determination of the sources of SOM. Furthermore, the abundance of aliphatic wax lipids in plant material and soils decreased at higher rates than the steroids and terpenoids indicating the preferential degradation of aliphatic over cyclic biomarkers. Most of the plant-derived steroids and terpenoids identified in the soils were unaltered, preserved biomolecules as observed in the source vegetation, but minor amounts of their degradation products were also present. Oxidation products of plant sterols are reported here for the first time in soils. The detected alteration products of steroids and diterpenoids are consistent with the oxidative degradation of free cyclic biomarkers in decomposing plant material and soils.

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“…The most abundant n-alkane in this fraction of bitumen in samples 1 and 3 is n-C 24 (Fig. 2), which suggests microbially mediated rework of n-alkanes of the native bitumen (Khan and Schnitzer 1972, Grimalt and AlbaigØs 1987, Lehtonen et al 2001. Obtained CPI values of associated bitumens B-2 are excluding the n-alkanes from peat as their significant components, and, because of lack of pristane and phytane, it is not likely that these bitumens can be attributed to oil pollution.…”

Section: Resultsmentioning

confidence: 95%

“…These extractions were performed under various experimental conditions, as: oxidation with alkaline copper (II) oxide (Lehtonen et al 2001), hydrolysis (Cranwell, 1981) and degradation of inorganic compounds (Jovančićević et al 1992). In this paper, we present the evidence that Vlasina lake peat, a recent sediment, contains free bitumen, as well as associated bitumens, which can be isolated under relatively mild extraction conditions.…”

Section: Introductionmentioning

confidence: 99%

Natural bitumens versus oil pollution in the Vlasina lake peat

et al. 2005

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Free and associated bitumens were isolated by sequential extraction from Vlasina lake peat (SE Serbia) and were investigated in order to differentiate between oil pollution and natural bitumens. Four peat samples were collected at different depths, on a peat island. Gas chromatographic (GC) and gas chromatography/mass spectrometry (GC/MS) analysis revealed the presence of three markedly different bitumen fractions. Here we show that the free bitumens are representing the native peat bitumens. The two associated bitumens are mainly the products of bacterial rework of organic substance, which were then trapped by two differing mechanisms. The bitumens characteristics and association features exclude a contribution of oil pollution.

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Structurally bound lipids in peat humic acids

Cited by 39 publications

References 48 publications

Comparative study for separation of atmospheric humic-like substance (HULIS) by ENVI-18, HLB, XAD-8 and DEAE sorbents: Elemental composition, FT-IR, 1H NMR and off-line thermochemolysis with tetramethylammonium hydroxide (TMAH)

Comparative study for separation of atmospheric humic-like substance (HULIS) by ENVI-18, HLB, XAD-8 and DEAE sorbents: Elemental composition, FT-IR, 1H NMR and off-line thermochemolysis with tetramethylammonium hydroxide (TMAH)

Degradation and Preservation of Vascular Plant-derived Biomarkers in Grassland and Forest Soils from Western Canada

Natural bitumens versus oil pollution in the Vlasina lake peat

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