Organic geochemical studies of a recent Inner Great Barrier Reef sediment—I. Assessment of input sources     

Philip M. Shaw  R.B. Johns 《Organic Geochemistry》1985,8(2):147-156

The concentration of solvent-extractable (SE) and bound hydrocarbons, ketones, alcohols, sterols, monocarboxylic acids, hydroxyacids and α,ω-dicarboxylic acids of a surface sample (0–2.5 cm) from a recent carbonate tropical sediment taken at 60ft (18m) depth north-west of the Low Isles, North Queensland, are reported in detail. n-Alkanes are a minor constituent in the SE and bound hydrocarbon fractions with the major component being unresolved complex hydrocarbon material which is not an anthropogenic input. 6,10,14-Trimethylpentadecan-2-one derived from chlorophyll, as well as phytol, were identified as major components of the ketone and alcohol constituents. No chlorophyll pigments or pigmented degradation products were present, implying degradation before incorporation into the sediment. This conclusion is consistent with evidence for higher-plant input in which all sensitive lipids have been degraded before incorporation. SE and bound fractions have been studied in detail and show considerable differences probably arising from the importance of viable biomass in the SE fraction. Inputs to the sediment are determined as higher plants, algae, bacteria, fungi and meiofauna in descending order of importance.  相似文献   

The importance of atmospheric input of terrestrial organic material to deep sea sediments     

Robert B. Gagosian  Edward T. Peltzer 《Organic Geochemistry》1986,10(4-6)

The concentrations of lipids were determined in atmospheric particle, gas and rain samples collected from the tropical North Pacific to assess lipid sources, transport mechanisms and fluxes to the ocean surface. Four lipid compound classes (aliphatic hydrocarbons, fatty alcohols, fatty acid esters, and salts) all unequivocally show a terrestrial vascular plant source. These aerosol lipids originate from wind erosion of Asian and American soils and direct emission from vegetation. The major fluxes result from rain rather than dry deposition. These fluxes are large enough to have a major potential impact on the inventory of terrestrially derived lipid material found in deep-sea sediments. This has been showm for n-alkanes, fatty alcohols, fatty acids, total lipids and for organic carbon. By comparing atmospheric and sediment trap fluxes with sediment accumulation rates, it is suggested that some biogenic terrestrial material is more protected from degradation than marine-derived material.  相似文献   

Emissions of Oxygenated Volatile Organic Compounds from Plants Part I: Emissions from Lipoxygenase Activity     

A. C. Heiden  K. Kobel  C. Langebartels  G. Schuh-Thomas  J. Wildt 《Journal of Atmospheric Chemistry》2003,45(2):143-172

Emissions of oxygenated volatile organic compounds (OVOC) from several plant species were measured in continuously stirred tank reactors (CSTR). High emission pulses of OVOCs were observed when plants were exposed to stress. Absolute emission rates were highly variable ranging up to 10^–13 mol · cm^–2 · s^–1. The temporal shape of these emissions was described by a formalism similar to that of a consecutive reaction of pseudo first order kinetics. The main emitted OVOC was (Z)-3-hexenol together with other C₆-aldehydes and alcohols, suggesting that lipoxygenase activity on linolenic acid was mainly responsible for OVOC production. Various stress factors induced lipoxygenase activity and subsequent emissions of OVOCs. These factors were exposure to high ozone concentrations, pathogen attack, and wounding. The pattern of OVOC emissions from tobacco was similar for different stress applications and the same products of lipoxygenase activity were emitted from all investigated plant species. Our results imply that these emissions occur as general response of the plants to stress. Since plants experience various abiotic or biotic stress factors in the environment, OVOC emissions as a response to stress are likely to be of significant importance for atmospheric chemistry.Now at  相似文献   

Geochemical significance of lipids and lipid-derived substructures interlaced in kerogen     

Kazuo Fukushima  Ryoshi Ishiwatari 《Organic Geochemistry》1988,12(6)

Young kerogens isolated from seven freshwater lakes, six river mouths and four marine surface sediments were subjected to pyrolysis in vacuo. Their pyrolysates were trapped and separated subsequently for determination of hydrocarbons, fatty acids and alcohols. The abundances, carbon number distributions of long (C₁₂) polymethylene chain lipid compounds and relative abundances of pristenes are proposed as possible indices applicable to discrimination between young kerogens from freshwater lacustrine and marine sediments. Some oil-shale kerogens of Eocene and Permian age were pyrolyzed in the same way, where the chain-length distributions of the pyrolysis products showed similar trends as those observed for the pyrolysis of young kerogens.  相似文献   

Marine and terrigenous lipids in coastal sediments from the Peru upwelling region at 15°S: Sterols and triterpene alcohols     

John K. Volkman  John W. Farrington  Robert B. Gagosian 《Organic Geochemistry》1987,11(6)

The distributions of free 4-desmethyl sterols in sediments from the Peru coastal zone at 15°S have been determined. Major free sterols in the surface sediments include cholesterol, which is mainly derived from zooplankton, and two C₂₈ sterols: 24-methylcholesta-5,24(28)-dien-3β-ol and 24-methylcholesta-5,22E-dien-3β-ol both of which are derived fro diatoms. Their concentrations decrease by almost an order of magnitude in the top 20 cm of sediment depth, indicating that free sterols are rapidly degraded in this sedimentary environment. Lipids from higher plants were also detected: long chain fatty acids and alcohols and various triterpenoid alcohols, including taraxerol, lupeol and α- and β-amyrin. The concentrations of most terrigenous lipids varied by less than a factor of 3 over the same depth, and these changes were not correlated with changes in the concentrations of total organic carbon. Below 3 cm, lipids from higher plants predominated in the extractable lipid distributions due to the more rapid degradation of marine lipids. We postulate that there are significant marine sources of the higher plant sterols 24-ethylcholesterol, 24-ethylcholesta-5,22E-dien-3β-ol and 24-methylcholesterol in these sediments. A high proportion of many of the terrigenous lipids in these sediments are probably transported into the coastal zone by rivers, rather than from the atmosphere, and then redistributed by bottom currents.  相似文献   

Aliphatic components of Victorian brown coal lithotypes     

Alan L. Chaffee  R.B. Johns 《Organic Geochemistry》1985,8(5):349-365

Victorian brown coal occurs in five major lithotypes distinguishable by colour index, petrography and bulk chemical analyses. The distributions of solvent extractable (free) and base hydrolysable (bound) n-alkanes, n-monocar?ylic acids, n-?,ω-dicar?ylic acids, n-ω-hydroxycar?ylic acids and n-alcohols were determined for samples of each of the five lithotypes (lithotype profile) and for seven samples of identical lithotype classification spanning a 100 m interval (depth profile) taken from a continuous bore core. The distributions of free molecular components in all classes are indicative of the predominant higher plant origin of this immature coal and provide strong support for the view that different lithotypes have derived from different, yet fairly specific paleobotanical communities. Despite an overall similarity in the distributions of aliphatic components from samples of identical lithotype classification, changes in the absolute concentrations and carbon preference indices (CPIs) of specific functional classes are observed in response to catagenetic influences even across the very small rank interval of the depth profile samples. Molecular distributions of bound components are similar to those of their free counterparts except that CPIs are generally lower and the relative contributions of lower molecular weight homologues (i.e. <C₂₂) are higher. Thedistributions of bound dicar?ylic acids and hydroxycar?ylic acids appear to reflect variations in the oxic/anoxic nature of the depositional paleoenvironments.  相似文献   

Comparison of lipid character of sediments from the Great Lakes and the Northwestern Atlantic     

Mary J. Leenheer  Kristine D. Flessland  Philip A. Meyers 《Organic Geochemistry》1984,7(2):141-150

Geolipid compositions of surficial sediments from Lake Michigan, Lake Huron, and from three locations in the Northwestern Atlantic were determined to compare source inputs and alteration processes in different sedimentary environments. Fatty acids, sterols, fatty alcohols, and alkanes were examined in both unbound and bound extracts of these samples. Significant amounts of long chain fatty acids, alcohols, and hydrocarbons are present in the deep ocean station, yet this location contains a proportionally larger amount of short chain geolipids than do marine stations closer to shore. Larger proportions of long chain lipids present in the Lake Michigan, Lake Huron, and Gulf of Maine samples relative to the open ocean samples reflect larger inputs of land-derived lipids to sediments closer to terrigenous sources. Marine samples contain a more complex mixture of sterols than is found in lake sediments, suggesting that sterol inputs and alteration processes in the marine environment are more complex than in lacustrine settings. Ratios of 16:1/16:0 and 18:1/18:0 fatty acids decrease with increasing distance from land, which suggests that fatty acid degradation before and during deposition becomes more extensive in the open deeper ocean stations.  相似文献   

Organic matter of the troposphere — V: Application of molecular marker analysis to biogenic emissions into the troposphere for source reconciliations     

Bernd R. T. Simoneit 《Journal of Atmospheric Chemistry》1989,8(3):251-275

Organic matter in tropospheric aerosols is derived from two major sources and is admixed depending on the geographic area. These sources are biogenic detritus and anthropogenic emissions. The biogenic materials in the solvent-extractable organic matter are comprised predominantly of higher plant waxes, with lesser amounts of resin and microbial detritus and the anthropogenic components are primarily vehicular emissions (e.g. oils, soot, etc.) and input from combustion (e.g. charcoal, thermally-altered biogenic matter, etc.). Both biogenic detritus and anthropogenic emissions contain organic compounds (C₁₂–C₄₀₊), which can be identified with unique and distinguishable distribution patterns. Molecular composition analysis has been applied to such extracts after suitable chemical separation into subfractions (i.e. hydrocarbons, ketones, aldehydes, carboxylic acids, alcohols, and wax esters). Both homologous compound series and specific natural products (e.g. phytosterols, terpenes, etc.) are identified as molecular markers.Aerosols from rural and remote areas in the western United States, South America, Nigeria and Australia have been analyzed and all contained predominantly plant waxes. The loadings of hydrocarbons ranged approximately from 10–1400 ng/m³ of air, of fatty acids from 10–450 ng/m³ and of fatty alcohols from 10–1650 ng/m³. These higher molecular weight lipids primarily from flora comprise a major component of the organic carbon in rural and remote aerosols. They are thus important indicators for regional biogenic sources in the global cycling of organic carbon.Presented in part at the International Symposium on Biosphere-Atmosphere Exchange, Mainz, E.R. Germany, March 16–22, 1986, for Part IV see Simoneit et al. (1988) Atmos. Environ. 22, 983–1004.  相似文献   

Simulated thermal alteration of sterols and keto—Alcohols in marine sediments of the Okinawa Trough     

Jiang Shanchun  John K. Volkman  Teresa O'Leary  Zhang Huizhi  Luan Zuofeng 《中国海洋湖沼学报》1993,11(4):343-350

Compositional data on the sterol and alcohol fractions isolated from deep-sea marine sediments from the Okinawa Trough were obtained to determine the relative contribution from marine and terrestrial inputs. Following extraction, the sterol plus alcohol fraction was isolated by layer chromatography, derivatized with BSTFA and then analysed by capillary GC and GC—MS. A suite of C₂₆−C₂₉ stenols and stanols and C₃₀−C₃₂ keto—alcohols were identified in the sediments. The thermal stability of the compounds in these sediments was studied by heating portions of the surface sediment in glass tubes for 16 hours at temperatures from 50°C to 200°C. The C₂₇ stanol/stenol ratio increased when temperatures went up to 175°C, but the distribution of C₃₀−C₃₂ Keto—alcohols remained unaffected. At 200°C most of the sterols and Keto—alcohols were destroyed. Supported by the National Natural Foundation of China.  相似文献   

绿河油页岩中的开链醇化合物     

汪双清  Rullkotter  王培荣 《沉积学报》2001,19(3):474-480

研究了美国绿河盆地的23个未成熟的露头油页岩样品,其中 13个样品取自Laney组,为半温湿半干燥气候下沉积于较浅的封闭水体的盐湖中心,含有丰富的有机质;另外 10个样品取自LumanTongue组,为潮湿气候下沉积于近岸的水体开放的淡水环境,其有机质含量较低。所有样品均富含从C₁₁至C₂₀ 的同分异构体丰富的饱和类异戊二烯醇类化合物。此外还检出了一整套直链一元仲醇同系物,其碳数从 10至 33,而羟基可在任何理论上可能的碳位上。伯醇含量较低。研究结果表明,绿河油页岩中的有机质分别在沉积过程中和被抬升之后遭受了两次微生物降解。除伯醇的分布有生物来源特征外,其余的开链醇化合物是在绿河层系抬升至地表后微生物对其中烃类化合物降解的产物。文中将绿河油页岩有机质中异常高的氧指数归因于微生物降解,并探讨了其开链醇化合物的分布与物源、沉积环境及微生物降解程度的相关性。盐湖相Laney组的直链醇以低碳数组分为主,反映其有机质以菌藻为主的物源,与干燥的古气候相一致;淡水相LumanTongue组则以高碳数组分为主,有着明显优势的高等植物来源,与其潮湿的古气候相吻合。在沉积过程中,淡水相的LumanTongue组中的有机质遭受了比盐湖相的Laney组中的有机质更强的微生物降解,这意味着盐湖环境。  相似文献