Organo-sulfur compounds in sediments of the Puget Sound basin

Sediment samples from a variety of different environments were analyzed for organo-sulfur compounds (OSC) to provide the first characterization of the amounts and types of these compounds in sediments of the greater Puget Sound basin. A gas Chromatograph equipped with a sulfur specific flame photometric detector was used to quantify individual OSC. Compositions of OSC mixtures were essentially constant throughout the study area. Dibenzothiophene (DBT), its alkylated homologs, and an unknown compound were the predominant OSC in most samples. Concentrations of total OSC and DBT ranged from 4 to 60 and 0.4 to 2 μg/g organic carbon, respectively. The flux of OSC to the sediments at a station in central Puget Sound west of Seattle was approximately 140 ng/cm²/yr. The profile of total OSC concentration with depth showed three organic sulfur compounds that are apparently created in situ in the vicinity of where hydrogen sulfide production begins. The concentrations of the aromatic OSC were relatively constant with depth. Although several anthropogenic sources of OSC were identified, there was no evidence that OSC from these sources were accumulating in the sediments. The major source of the aromatic OSC in the sediments is apparently atmospheric input from natural sources such as forest fires.     

Effect of water washing on hydrocarbon compositions of petroleum sandstone reservoir rocks in Tarim Basin, NW China

Gross compositions and distribution of saturated and aromatic hydrocarbons in Carboniferous sandstone reservoire rocks in oil and water zones for Tzhong-10 well of the Zhongyang Uplift in the Tarim Basin were studied in dteail by means of Rock-Eval Pyrolysis,thin-chromatograph-flame ionization detection(TLC-FID),gas chromatography,gas chromatography-mass spectrometry.The results suggest that the gross composition of reservoir hydrocarbons between the oil zone and the water zone show significant differences,Water wahing has a dramatic effect on saturated hydrocarbon blomarkers,especially drimane series compounds,Drimane series compounds in the water zone have been depleted completely.However,the contents of tricyclic iterpanes and pentacyclic triterpanes tend to decrease slightly,but the water-zone reservoir hydrocarbons contian a large amount of gammacerane.This suggests that gammacerane be more resistant to water washing than diterpanes and homohopanes.The contents of pregnane,homopregrane,diasteranes relastively decrease as a result of water washing.Water washing has a noticeable effect on polycyclic aromatic hydrocarbon compounds,especially aromatic sulfur compounds,and the contents of dibenzothiophene series compounds and benzonaplyiothipophene decrease significantly as a result of water washing.However,the conterts of bicyclic and tricyclic aromatic hydrocarbons decrase slightly and those of tetracyclic and pentacyclic aromatic hydrocarbons,especially benzofluoranthene and benzopyrenes,increase markedly owing to adecrease in light aromatie hydrocarbons as a result of water washing.     

The distribution of dibenzothiophenes in Gulf of Mexico sediments

Sediment extracts from 81 piston cores taken in water depths between 70 and 1200 m on the Gulf of Mexico continental shelf and slope were analyzed for dibenzothiophenes by capillary gas chromatography with flame photometric detection (FPD). The major aromatic sulfur compounds detected were dibenzothiophene; methyl, ethyl and propyl dibenzothiophenes; two unidentified sulfur compounds; and a series of benzothiophenes. In general, benzothiophenes (BTs) were detected at only trace levels though this may be due to loss during the analysis. Dibenzothiophenes (DBTs) concentrations ranged from <1 to 1725 ng/g, with an average of 139 ng/g. Vertical distributions generally showed significant increases in DBTs concentrations with depth. DBTs distributions in sediment extracts were similar to oils produced in the northern Gulf of Mexico. Variations from this composition may be due to microbial degradation in the near subsurface. The vertical and molecular distribution of DBTs suggests that the source of DBTs in the Gulf of Mexico sediments studied is upward migrating petroleum. Two unidentified compounds are speculated to be derivatives of DBTs, caused by indigenous microbial activity. This study suggests that DBTs may be useful for detecting seepage from deeper, more mature, source rocks and/or reservoired petroleum.     

刍云深水凹陷高成熟原油芳烃地球化学特征研究

对白云凹陷采集的27个原油样品的芳烃组成进行了系统的研究。其分布特征和相对含量表明,原油母质具明显的陆源高等植物输入特征,沉积环境以氧化环境为主,根据萘系列、菲系列、二苯并噻吩系列化合物的相对含量分布差异,优选有效的烷基萘、烷基菲、烷基二苯并噻吩成熟度指标,综合分析了白云凹陷原油成熟度特征。原油总体属于成熟一高成熟原油,结合生物标志化合物组成可划分为A、B两类,A类原油的成熟度高于B类原油。还选用有效的成熟度参数探讨了白云凹陷油气运移规律,如三甲基萘比值,该参数指示油气运移方向沿白云主洼中心向周围运移,且邻近番禺低隆起,运移方向由西向东,即沿着成熟度由高到低方向运移。     

Sample preparation for analyzing polycyclic aromatic hydrocarbons and polychlorinated dibenzo-p-dioxins and dibenzofurans in sediment by gas chromatography/mass spectrometry

A sample preparation technique was developed to isolate and separate two classes of combustion-produced pollutants: three- to six-ring polycyclic aromatic hydrocarbons (PAH) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F), from sediment samples for interference-free analyses by gas chromatography/mass spectrometry (GC/MS). The method involves soxhlet extraction with methylene chloride, sulfur removal with activated copper powder, gel filtration chromatography with Sephadex LH-20, polarity separations of PAH and PCDD/F with prepacked silica gel solid-phase extraction columns, and isolation of PCDD/F from polychlorinated biphenyls with microalumina columns. Stringent procedural controls were established to achieve clean isolations and recoveries of 70% or better for each step in the method. The prepared sample extracts were analyzed by capillary GC and GC/MS. Electron impact ionization was used for PAH, and negative chemical ionization with methane as a reagent gas was used for PCDD/F. Reproducible results were obtained. The method is simple and has the advantage of conserving sample consumption since two classes of compounds can be analyzed from the same sample. This can be critical in sediment core analyses where sample size is usually limited.     

Geochemical study on a well in the Western Canada Basin: relation of the aromatic distribution pattern to maturity of organic matter

Thirty-one rock samples from a Western Canada Basin well have been analysed for aromatics, using glass capillary gas chromatography with simultaneous flame ionization and sulfur-selective flame photometric detection. A uniform aromatic distribution pattern with a marked predominance of di- and tricyclic aromatic hydrocarbons was observed throughout a depth interval of 3000 meters comprising Cretaceous and Jurassic sediments. The very high relative abundance of sulfur aromatics at two narrow intervals in the Triassic and Mississippian is attributed to a major change in facies. Gradual changes with increasing depth have been observed for a series of compound ratios, which had been calculated from the isomers of methyl- and dimethylphenanthrene, and their parent compounds. These changes reflect the increasing thermal maturation of the sedimentary organic matter. A Methylphenanthrene Index (MPI) has been introduced, which exhibited a very good correlation with vitrinite reflectance data. The MPI is the first maturity parameter which is based on a series of aromatic hydrocarbons. This hydrocarbon internal maturity parameter permits the recognition and definition of maturity levels in extracts which can be compared to the maturity (e.g. vitrinite reflectance) of source rocks.     

New aromatic biomarkers in sulfur-rich coal

A molecular study of linear, branched and isoprenyl alkylbenzene skeletons and alkenylbenzenes in the soluble fraction extracted from a sulfur-rich Utrillas coal was carried out using gas chromatography–mass spectrometry (GC–MS). The presence of C₂₄–C₂₈ diaromatic compounds, not previously reported in coals, suggests that photosynthetic green sulfur bacteria may have made an input of organic matter to these coals. The unsaturated linear alkenylbenzenes and isoprenyl (C₁₅ and C₂₀) alkylbenzene skeletons are also described for the first time in the soluble fraction of geological samples.     

Molecular fossils in Cretaceous condensate from western India

The present study reports the biomarker distribution of condensate belonging to the early Cretaceous time frame using gas chromatography–mass spectrometry (GC–MS). The early Cretaceous palaeoenvironment was inscribed into these molecular fossils which reflected the source and conditions of deposition of the condensate. The saturate fraction of the condensate is characterized by normal alkanes ranging from n-C₉ to n-C₂₉ (CPI-1.13), cycloalkanes and C₁₄ and C₁₅ sesquiterpanes. The aromatic fraction comprises of naphthalene, phenanthrene, their methylated derivatives and cyclohexylbenzenes. Isohexylalkylnaphthalenes, a product of rearrangement process of terpenoids, is detected in the condensate. Several aromatic sesquiterpenoids and diterpenoids have been recorded. Dihydro-ar-curcumene, cadalene and ionene form the assemblage of sesquiterpenoids which are indicative of higher plant input. Aromatic diterpenoid fraction comprises of simonellite and retene. These compounds are also indicative of higher plants, particularly conifer source which had been a predominant flora during the Cretaceous time.     

高有机硫煤抽提物中含硫化合物的组成与热演化特征

高有机硫煤是一种十分特殊的煤种,其特点之一是抽提物芳烃馏分中含丰富的含硫化合物。在我国西南地区晚二叠世碳酸盐台地潮坪成因、具不同煤化程度的四种高有机硫煤中均检测出了四种系列的含硫化合物,它们分别为二苯并噻吩系列、苯并萘并噻吩系列、菲并噻吩系列和苯并二苯半噻吩系列。含硫化合物的类型组成虽然相似,但它们的相互比例关系与煤化程度和具体的沉积环境密切相关。分析发现,随煤化程度增加:（1）具三环结构的二苯并噻吩相对于四、五环结构的化合物数量减少;（2）具稳定甲基取代位的含硫化合物数量不断增加,同时还发现含硫化合物与同环数的常规芳烃间的比值可反映碳酸盐台地受局限的程度。     

The impact of thermal maturity level on the composition of crude oils,assessed using ultra-high resolution mass spectrometry

We have examined, using a 12 Tesla FTICR-MS instrument, the impact of varying thermal maturity level on a suite of 9 related crude oils charged from source rocks covering most of the liquid petroleum generating portion of the oil window (0.68–1.11% vitrinite reflectance equivalent (%Re)). The sample suite was analyzed as whole oils under three different conditions, electrospray ionization (ESI) in positive and negative ion mode to analyze basic and acidic components, respectively, and atmospheric pressure photoionization (APPI) in positive ion mode, for sulfur and hydrocarbon species.Increasing oil maturity level had a strong influence on the composition of all compound classes in the oils with several major observations evident:The relative apparent abundances of all heteroatom containing compound classes detected in this study, using all ionization modes, decrease systematically with increasing oil maturation levels. Both aromatic hydrocarbons, detectable in APPI mode, and NSO compound classes (detectable in both ESI and APPI modes), as broad classes, are becoming more aromatic (shift to a greater predominance of higher DBE group members) and dealkylated (decreasing average molecular mass of individual compound groups), with increasing maturation level in the oil suite. Several putative oil maturity level dependent, molecular ratios were identified in the study. Of particular note, the relative abundance ratios of heteroatom compound classes tentatively identified as alkylated carbazoles, quinolines and benzothiophenes, compared to their benzannulated homologues are very sensitive to maturation level. Several groups of compounds show interesting and specific carbon number distributions, suggesting there may be hints of specific molecular markers in the FTICR-MS data. One observation of note is the strong increase in the relative abundance of protonated hydrocarbon components with DBE 5. We speculate this might reflect the presence of previously unreported higher molecular weight diamondoid (diamantane) species in oils with up to 40 carbon atoms or more, at advanced maturity levels. Such species may prove very valuable as molecular markers in highly mature fluids, such as those currently being produced from some shale reservoirs. Covariation of quantitative GC–MS data for alkylated hetero aromatic sulfur and nitrogen compounds in this oil suite, together with the corresponding FTICR-MS data from compounds believed to be, based on accurate mass, alkylated sulfur and alkylated nitrogen compounds, suggests that FTICR-MS already has some very rudimentary quantitation capabilities.     

Terpenoid marker compounds derived from biogenic precursors in volcanic ash from Mount St. Helens,Washington

A volcanic-ash sample obtained after the 1980 eruption of Mount St. Helens, Washington, was analyzed for cyclic terpenoid organic compounds and polycyclic aromatic hydrocarbons using capillary gas chromatography-mass spectrometry-computer techniques. Various tricyclic diterpenoid acids and hydrocarbons were identified including dehydroabietic acid, dehydroabietin, dehydroabietane, simonellite, and retene. Preliminary evidence indicates that these compounds were derived from forest soils or atmospheric aerosols or both in the vicinity of coniferous forests. A diagenetic scheme involving three possible pathways for the conversion of abietic acid to retene is presented.     

Analysis of some aromatic hydrocarbons in a benzene-soluble bitumen from Green River shale

The hydrocarbon content of an aromatic fraction, isolated from the bitumen of Green River shale, was studied by mass spectrometry, infra-red spectrometry, gas chromatography and a dehydrogenation technique. The hydrocarbon types and their distribution in this aromatic fraction, as determined by mass spectrometry, include the following: C_nH_2n?6(10%), C_nH_{2n?8 (31 %)}, C_nH_2n?10(18%), C_nH_2n?12(12%), C_nH_2n?14(8%) and a series of alkenylbenzenes (20%). The carbon-number range, empirical formulae and quantity of each compound in the major types are reported. Mass spectra of several compounds and homologous mixtures of compounds isolated from the aromatic fraction are also given.     

鄂尔多斯盆地西峰油田原油芳烃地球化学研究

通过对鄂尔多斯盆地西峰油田原油进行系统地采样和高分辨率的GC-MS分析,研究了原油的芳烃组成特征,进行了油源对比,探讨了原油成因。结果表明:所分析原油属于同一成因类型;烷基萘和含硫芳烃的分布特征与有机质类型和沉积环境密切相关;西峰油田原油形成于弱还原环境,为菌藻类和高等植物母质来源,特别是高等植物为原油的形成做出了重要贡献,成熟度较高。原油地球化学特征和上三叠统延长组长7油层组烃源岩相似,反映了原油主要来源于长7油层组。这些研究结果为盆地石油的进一步勘探提供了一定科学依据。     

Polycyclic aromatic hydrocarbons in the Murchison meteorite

More than thirty polycyclic aromatic hydrocarbons, including nine heterocyclic aromatic compounds, have been identified in solvent extracts of the Murchison meteorite by gas chromatography-mass spectrometry using bonded-phase fused silica columns. Structural isomers of several alkylated aromatic hydrocarbons, including methylpyrene and methylphenanthrene were chromatographically separated, thus allowing calculations of the amount of alkyl substituted compounds in the solvent extracts. The ratio of odd-carbon number to even-carbon number was found to be approximately 0.1. Based on these data and literature data from model pyrolysis experiments, a temperature of 1000°C is suggested for the formation of polycyclic aromatic hydrocarbons in the solar nebula or premeteoritic body. The value of 1000°C is within the range of temperatures for the condensation of the nebular material from the initial high temperature phases to the lower temperature phases at which chemical and isotopic equilibria were frozen. A simple model for the abiotic synthesis of heterocyclic compounds from simple aliphatic precursors is also presented.     

板桥凹陷原油芳烃组成特征及地球化学意义

板桥凹陷原油以低密度、低粘度、低含硫和高凝固点、高含蜡量为特征的中—高蜡凝析油—轻质油为主。芳烃色谱—质谱分析结果显示,常规多环芳烃含量高达66.33%～80.81%;其次是三芴系列,在15%～30%之间;芳香甾烷系列含量仅有5.55%。常规多环芳烃又以二环的萘系列和三环的菲系列为主。用甲基菲指数（MPI1）折算的RC反映板桥凹陷原油处于成熟—高成熟阶段,其中,板深35原油（Es3,4 731 m）折算的RC值达到1.60%。三芳甾烷含量和低碳数三芳甾烷比值与甲基菲指数（MPI3）、甲基二苯并噻吩指数（MDR）均有良好的相关性。三芴系列组成特征反映了原油成因环境为偏沼泽相的弱氧化—还原环境。     

Geochemical characteristics of the macromolecular part of crude and biodesulphurised flame coal density fractions

Flame coal (Janina Mine, Poland) was an object of geochemical analyses for changes caused by the process of microbial desulphurisation. Ash content, beryllium, chromium, zinc, cobalt, lithium, manganese, copper, molybdenum, nickel, lead and vanadium concentrations were investigated in coal extracts, its macromolecular part, semi-coke and polar compound fractions of extracts and pyrolysates of crude and biodesulphurised coal density fractions. The macromolecular part of extracted density fractions was pyrolysed giving semi-coke and pyrolysate. These were separated into aliphatic hydrocarbons, aromatic and polar compounds by thin layer chromatography (TLC). Distributions of aliphatic and aromatic hydrocarbons in pyrolysates of the crude and desulphurised coal density fractions were compared by gas chromatography-mass spectrometry (GC-MS). Extracts, extracted density fractions, semi-coke and polar compound fractions were analysed for concentrations of trace elements. In the crude coal their concentrations in the macromolecular part are related only to coke. However, in the desulphurised coal the participation of the particular trace element increases in pyrolysate polar compound fractions. Its values are in the range from 1% (Mn) to 100% (Cr and Mo). These changes are the best seen in the 1.80-2.30×10³ kg/m³ density fraction. Very high concentrations of trace elements were found in pyrolysate of desulphurised coal density fraction. This can be explained by the partial decomposition of coal macromolecule resulting from desulphurisation. Significant side-cleavage of peripheral groups and lighter aromatic hydrocarbons is possible. The effects of bacterial influence were manifested by the increase of polar compounds contents both in pyrolysates and extracts of the desulphurised coal and changes in distribution of aliphatic and aromatic hydrocarbon as pyrolytical products. These effects increase with mineral substance contents. Moreover, the increase of trace element concentration in coal organic matter occurs. It is reflected by the increase of participation of coal pyrolysate polar fraction in the total concentration of analysed elements in the macromolecular part of a given density fraction. The presented results are a part of the larger research aimed to find an influence of desulphurisation on chemical and technological properties of coal.     

Identification and determination of PAHs compounds in Anzali International Wetland

The worst environmental pollutants in Anzali International Wetland are oily hydrocarbons especially aromatic and poly aromatic compounds (PAHs). The existence of oily compounds with approximate limit of concentration of 0.1 μg/l in aquatic environment bans the growth of fish larva and causes the generic state manner of animals. Anzali International Wetland, which is situated in the west — southern part of Caspian Sea where has environmental importance in life of living organisms and ecosystems. In this reseach, four sites, Pirbazar, Pasikhan, west and central parts, where are situated in Anzali International Wetland, have been studied in 2002. Waste sedimentation soil Sampling was performed during winter and spring in the above-mentioned regions. In the first stage, the purpose of sampling was to access optimum instrumental conditions and correct and precise procedures. Oily pollutants were extracted from water and it was done by using CC1₄ solvent after cleaning and concentrating. The extracted samples were identified with gas chromatographic method with using polyaromatic standard solutions. By the powerful GC/MS method; results of qualitative analysis were confirmed. Also by GC/MS using SIM mode quantitative analysis were performed. Quantitative study of polyaromatic compounds has also been done by luminescence spectrophotometry. Some compounds which were identified in the water samples were: olifinic, aromatic and poly — aromatic compounds such as: antracene, fluourine, xylene, methylbenzene, naphthalene and acenaphtylene. Finally, the degree of biodegradation of compounds such as pristan (C₁₉H₄₀) and phytan (C₂₀H₄₂) in water samples was integrated.     

Influences of the basin brines on extractable bitumen of Kupferschiefer from southwestern Poland

A study of the influences of the basin brines on hydrocarbon generation of the Kupferschiefer in southwestern Poland has been carried out.The samples from the Konrad and Polkowics mines were analyzed by orgainc geochemical,microscopic and FTIR methods.The results indicate that organic matter of Kupferschiefer tends to decrease with the ascending,oxidizing brines,In the Konrad profile,the Kupferschiefer was strongly oxidized.The extract yields were depleted up to 50mg Ext/g Corg.Gas chromatography(GC) and gas chromatography-mass spctrometry(GC/MS) data indicate that the depletion occureed predominantly in saturated hydrocarbon compounds.The identified n-alkanes in smpale KD1 were depleted at least to 5000μg/g Corg.The aromatic compounds show a fidderent trend of variation.The concentrations of phenanthrene alkylphenanthrenes(Ph-PAH) and naphthalene alkylnaphthalenes(Na-PAH) show a decrease,whereas sulfur polyaromatic hydrocarbons(S-PAH)and oxygen polyaromatic hydrocarbons(O-PAH) show an incrase under the influences of oxidizing brines,In the Polkowice profile,organic matter under the influences of oxidizing fluids shows a simlar trend of varation as in the Konrad mine.Analyses of polar compounds shed light on the oxidation processes at the molecule level.The dominant products of oxidation are aliphatic acid.alcohol and ester.FTIR results indicate that the oxidation of organic matter led to a decrease in aliphatic CH3 and an increase in C-O,C=O bands.     

Effects of weathering on organic matter: Part II: Fossil wood weathering and implications for organic geochemical and petrographic studies

Bulk geochemical, petrographical, mineralogical and molecular compositions of unweathered, weathered and transitional zones of a Middle Jurassic fossil wood were analyzed to trace changes caused by oxidative weathering of the immature terrestrial organic matter (OM). The occurrence of such zones was confirmed by the mineral composition, showing replacement of siderite and pyrite by goethite. Vitrinite reflectance analysis of weathered and unweathered fossil wood samples revealed that weathering elevated the vitrinite reflectance values by ca. 0.1%, which should be taken into account during modeling of low maturity terrestrial OM. In the weathered part of the wood, most of the biomarkers and biomolecules were totally removed or the concentration decreased significantly. The concentration of most of the polynuclear aromatic hydrocarbons (PAHs) decreased by 50–80%, being >90% for the more reactive and less stable benzo[a]pyrene and perylene. On the other hand, several aromatic compounds, like phenanthrene and its methyl derivatives, phenyl naphthalenes, fluoranthene and oxygen-containing aromatic compounds increased in concentration in the weathered zone. This results from processes such as formation of phenyl derivatives of PAHs and their cyclization, as well as aromatization of diterpenoids and incorporation of oxygen into aromatic structures. Weathering should always be considered in studies of fossilized terrestrial OM, especially in the case of thermal maturation modeling, because it significantly decreases the OM content and total sulfur content, changes vitrinite reflectance values and alters the extract composition as a result of organic compound degradation.     

Identification and emission factors of molecular tracers in organic aerosols from biomass burning Part 2. Deciduous trees

Smoke particulate matter from deciduous trees (angiosperms) subjected to controlled burning, both under smoldering and flaming conditions, was sampled by high volume air filtration on precleaned quartz fiber filters. The filtered particles were extracted with dichloromethane and the crude extracts were methylated for separation by thin layer chromatography into hydrocarbon, carbonyl, carboxylic acid ester and polar fractions. Then, the total extract and individual fractions were analyzed by gas chromatography and gas chromatography–mass spectrometry. The major organic components directly emitted in smoke particles were straight chain aliphatic compounds from vegetation wax and triterpenoid acids (biomarkers) from gums and mucilages. The major natural products altered by combustion included derivatives from phenolic (lignin) and monosaccharide (cellulose) biopolymers and oxygenated and aromatic products from triterpenoids. Steroid biomarkers and polycyclic aromatic hydrocarbons (PAH) were also present, however, as minor constituents. Although the concentrations of organic compounds in smoke aerosols are highly variable and dependent on combustion temperature, the biomarkers and their combustion alteration products are in these cases source specific. The major components are adsorbed or trapped on particulate matter and thus may be utilized as molecular tracers in the atmosphere for determining fuel type and source contributions from biomass burning.