Identification Of Hydrocarbons Research Articles

Chromatographic and spectroscopic analysis of heavy crude oil mixtures with emphasis in nuclear magnetic resonance spectroscopy: A review

The state of the art in the characterization of heavy crude oil mixtures is presented. This characterization can be done by different techniques, such as gas chromatography (GC), high performance liquid chromatography (HPLC), thin layer chromatography (TLC), infrared spectroscopy (IR), Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). Nuclear magnetic resonance spectroscopy is the technique of choice due to its capability to provide information on the chemical nature of individual types of hydrogen and carbon atoms in different and complex mixtures of crude oils. The progress made in the interpretation of the NMR spectra with the development of new NMR techniques and different multivariate data analyses could give relevant information about the identification and characterization of hydrocarbons and their physical and chemical properties. These progresses can improve the refining industries operation as a result of the better knowledge on the crude composition that is fed in the refining process, as well as in the prediction of better operating conditions to obtain refined products with desired specifications and in quantities desirable to meet the market demands. The improvement in the refining operation conditions is reflected in economical benefits.

Identification of benzothiazole derivatives and polycyclic aromatic hydrocarbons as aryl hydrocarbon receptor agonists present in tire extracts.

Leachate from rubber tire material contains a complex mixture of chemicals previously shown to produce toxic and biological effects in aquatic organisms. The ability of these leachates to induce Ah receptor (AhR)-dependent cytochrome P4501A1 expression in fish indicated the presence of AhR active chemicals, but the responsible chemicals and their direct interaction with the AhR signaling pathway were not examined. Using a combination of AhR-based bioassays, we have demonstrated the ability of tire extract to stimulate both AhR DNA binding and AhR-dependent gene expression and confirmed that the responsible chemicals were metabolically labile. The application of CALUX (chemical-activated luciferase gene expression) cell bioassay-driven toxicant identification evaluation not only revealed that tire extract contained a variety of known AhR-active polycyclic aromatic hydrocarbons but also identified 2-methylthiobenzothiazole and 2-mercaptobenzothiazole as AhR agonists. Analysis of a structurally diverse series of benzothiazoles identified many that could directly stimulate AhR DNA binding and transiently activate the AhR signaling pathway and identified benzothiazoles as a new class of AhR agonists. In addition to these compounds, the relatively high AhR agonist activity of a large number of fractions strongly suggests that tire extract contains a large number of physiochemically diverse AhR agonists whose identities and toxicological/biological significances are unknown.

Source identification and health risk of polycyclic aromatic hydrocarbons associated with electronic dismantling in Guiyu town, South China

In this study the concentrations and distribution of sixteen polycyclic aromatic hydrocarbons (PAHs) were investigated in gas and total suspended particle (TSP) samples collected during daytime and night time. The sampling locations included an electronic waste dismantling workshop (EW), a plastic recycling workshop (PW) and a waste incineration field (WF) in Guiyu, China. A large residential area (RA) in this region was used as a control site. In the daytime, the highest concentration was found at WF (1041 ng m −3); while in the night time the highest concentration was found outside of EW (744 ng m −3). Comparison between work hours (daytime) and rest hours (night time) displayed that the total PAHs (gas + particulate phase) concentrations and the percentages of PAHs associated with TSP were higher at night than those in the daytime in all sampling workshops except WF. Source diagnostic-ratio analysis revealed that unwanted materials and smoldering honeycomb coals were the main sources of PAHs in EW, WF and PW. Benzo[ a]pyrene equivalent [BaPeq] concentrations calculated by using the toxic equivalent factors [TEFs] suggested that the occupational exposure levels were not significantly high when compared with other occupational exposure. Additionally, our study suggested that the smoldering of unwanted materials could produce much more toxic PAHs compounds.

Contamination, source identification, and risk assessment of polycyclic aromatic hydrocarbons in agricultural soil of Shanghai, China

The level, distribution, compositional pattern, and possible sources of polycyclic aromatic hydrocarbons (PAHs) in agricultural soil of Shanghai were investigated. The concentrations ranged from 140.7 to 2,370.8 μg kg( -1) for 21 PAHs and from 92.2 to 2,062.7 μg kg( -1) for 16 priority PAHs, respectively. The higher level of PAHs was mainly distributed in the south and west of Shanghai region, and the lower concentration was found in Chongming Island. Generally, the composition pattern of PAHs was characterized with high molecular weight PAHs, the seven possible carcinogenic PAHs accounted for 4.8-50.8% of the total PAHs, and fluoranthene, pyrene, and benzo[b]fluoranthene were the most dominant components in soil samples. The correlation analysis suggested that low molecular weight PAHs and high molecular weight PAHs were originated from different sources and further corroborated that total organic carbon was a key soil property affecting the fate of persistent organic pollutants in the environment. The isomer ratios and principal component analysis indicated that PAHs in the investigated areas were derived primarily from combustion of biomass, coal, and petroleum. Compared to the soil quality standards of the Netherlands, all the target PAHs (except Ant) in most samples exceeded their target values. The Nemerow composite index based on the same soil quality standard showed that 69.4% of the soil samples were heavily polluted. The total BaP(eq) of ten Dutch target PAHs in 72% soil samples were higher than the reference total carcinogenic potency. Therefore, the agricultural soil in Shanghai is suffering from serious PAHs contamination.

Coaxial fiber-optic chemical-sensing excitation–emission matrix fluorometer

Great reductions in the overall size and complexity of high throughput multichannel UV-visible fluorometers were achieved by coupling a compact optical fiber array to compact dispersive transmission optics. The coaxial configuration centers on the insertion of a silica/silica optical fiber into the hollow region of a UV-fused silica capillary waveguide. The outer core delivers the maximum power of the narrow wavelength region of the excitation spectrum created by coupling a xenon arc discharge lamp to a compact spectrometer. The molecular fluorescence resulting from the interaction of light emitted at the distal end of the hollow waveguide and the sample matrix is received and transmitted to a CCD via a compact dispersive grating-prism (grism) optical assembly. A linear array of the coaxial optical fibers permits a full excitation-emission matrix spectrum of the analyte matrix to be projected onto the face of the CCD. The in situ identification and monitoring of polycyclic aromatic hydrocarbons was carried out for the initial application testing for this prototype.

Results of NMR spectroscopic studies of hydrocarbon conversions on solid acid catalysts in the last 25 years

High-resolution solid-state NMR studies of hydrocarbon conversions on the surface of solid acid catalysts are overviewed. The results of identification of hydrocarbons adsorbed on solid acid catalysts are presented. Alkane activation and hydrocarbon conversion mechanisms and the nature of reactive intermediates are discussed. It is demonstrated that NMR spectroscopy can be used not only in the in situ analysis of hydrocarbons on the catalyst surface, but also as a method for seeking new hydrocarbon conversion routes.

Chemical Characterization and Source Identification of Polycyclic Aromatic Hydrocarbons in Aerosols Originating from Different Sources

To obtain the characteristic factors or signatures of particulate polycyclic aromatic hydrocarbons (PAHs) to help identify the sources of particulate PAHs in the atmosphere, different carbonaceous aerosols were generated by burning different fossil fuels and biomass under different conditions in the laboratory, and the chemical characteristics of 14 PAHs were studied in detail. The results showed that (1) carbonaceous aerosols derived from domestic burning of coal, diesel fuel, and gasoline have much higher concentrations of PAHs than those derived from domestic burning of biomass; (2) carbonaceous aerosols derived from domestic burning of diesel fuel/gasoline have similar PAH components as those derived from high-temperature combustion of diesel fuel/gasoline, although the former have much higher concentrations of PAHs than the latter, suggesting that the burning temperature obviously affects the emitting amount of particulate PAHs, but only slightly influences the PAHs components; and (3) the ratios of benzo[b]fluoranthene/acenaphthylene, benzo-[b]fluoranthene/fluorene, dibenzo[a,h]anthracene/acenaphthylene, dibenzo[a,h]anthracene/fluorine, and benzo[b]fluoranthene/benzo[k]fluoranthene in carbonaceous aerosols are sensitively dependent on their sources, indicating that these ratios are suitable for use as characteristic factors or signatures of particulate PAHs in the atmosphere.

Source Identification of Atmospheric Polycyclic Aromatic Hydrocarbons in Industrial Complex Using Diagnostic Ratios and Multivariate Factor Analysis

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants worldwide; currently, they are being described as potential persistent organic pollutants (POPs). This study is aimed to identify sources of PAHs in the atmosphere around the Sihwa and Banwol industrial area by using diagnostic ratios and multivariate factor analysis such as principal component analysis/absolute principal component score (PCA/APCS) and positive matrix factorization (PMF). The atmospheric PAHs level was 8.07-177 ng/m(3) (gaseous phase: 5.93-68.4 ng/m(3); particulate phase: 1.85-128 ng/m(3)) and PAHs concentration in the warm period was lower than the cold period. As a result of the examination of relative BaP concentration, photodecomposition was found not to be an important factor in the seasonal difference of PAHs concentration in this study. Source identification was first carried out through a double ratio plot. As a result of double ratio plots, atmospheric PAHs in this study were found to stem from the combination of vehicular emission, combustion (coal or biomass-wood or grass), and petroleum. Moreover, PCA/APCS and PMF showed that the main sources were vehicular emission and coal combustion and and incineration-related source with a summed contribution of about 72.6-86.7%. Finally, the fitness of the two models was very good; the estimated values were highly correlated with the measured values (R(2) = 0.991-0.999, p < 0.05).

Recognizing and compensating for interference from the sediment’s background organic matter and biodegradation during interpretation of biomarker data from seafloor hydrocarbon seeps: An example from the Marco Polo area seeps, Gulf of Mexico, USA

A suite of seep samples from the vicinity of the Marco Polo field in the Green Canyon area of the Gulf of Mexico provides an exceptional opportunity to study the impact of interference from sediment background organic matter and alteration by biodegradation on thermogenic hydrocarbons from seafloor seeps. These seep samples contain a range in both the concentration of seeped hydrocarbons present and level of biodegradation experienced. In addition, the subsurface oil that sources the seepage was available for comparison. The results of the study show that it is essential to have the biomarker data from the sediment’s background organic matter when dealing with low concentration seepage. These data provide a means to characterize the contribution of background organic matter to the biomarker distributions. This, in turn, allows the identification of thermogenic hydrocarbons when the concentration of seeped oil in seafloor sediments is low. In high concentration seepage, the hopanes and regular steranes were found to be more susceptible to near-surface microbial alteration, while tricylic/tetracyclic terpanes, diasteranes, monoaromatic steroids, and triaromatic steroids were more resistant. If biodegradation is severe enough, all biomarker compounds are vulnerable to alteration and very little information is preserved. In an effort to reconstruct the altered distributions, low temperature pyrolysis of the seeped oils’ asphaltenes was done to liberate occluded biomarkers compounds. Although biomarkers were recovered, they did not resemble the parent oil. Characteristics of some of the recovered biomarker distributions suggest alteration by biodegradation. This implies the three dimensional structure of the asphaltenes may not offer complete protection from microbial attack. These results demonstrate why interpretation of biomarker data from seafloor seeps can be a difficult task. Care must be taken to recognize contributions from the sediment’s background organic matter as well as identify alteration by biodegradation. Failure to understand these processes can lead to erroneous interpretations being made about the seep’s parent oil and source rock.

ChemInform Abstract: Identification of Sesquiterpene Hydrocarbons by Gas Phase Analytical Methods

Current techniques are described and demonstrated for the isolation and structural elucidation of sesquiterpene hydrocarbons, on the basis of enantioselective capillary gas chromatography, with cyclodextrin derivatives as chiral stationary phases and chemical microreactions for correlation of unknown sesquiterpenes with compounds of known constitution and absolute configuration. Copyright © 1999 John Wiley & Sons, Ltd.

Thermal Decomposition of Acetic and Formic Acid Catalyzed by Red Mud—Implications for the Potential Use of Red Mud as a Pyrolysis Bio-Oil Upgrading Catalyst§Dedicated to Prof. Ulf Schuchardt on the occasion of his retirement.

Acetic and formic acid impart a high acidity on pyrolysis bio-oil (obtained by fast pyrolysis of ligno-cellulosic biomass), which is one of the factors preventing its direct use as a fuel. At temperatures ≥ 330 °C, Red Mud, a waste byproduct of the aluminum industry produced at >70 million tons p.a., is a good catalyst for thermal decomposition of these acids. Formic acid can serve as an internal source of hydrogen through the formation of synthesis gas and the water gas shift reaction. The formation of C6−C10 hydrocarbons in the nonpolar phase of the resulting product mixture and the identification of C3 and C4 hydrocarbons and CO2 in the gas phase and acetone in the polar liquid phases can be rationalized through mechanisms involving ketene as the intermediate formed by acetic acid dehydration, with subsequent formation of acetone. Higher hydrocarbons, mostly alkanes and alkenes, are then formed through iterative aldol condensation, hydrogenation, hydrogenolysis, and deoxygenation reactions of the prima...

Identification of hydrocarbons from Abies pindrow leaves

The genus Abies family Pinaceae consists of 51 species ranged mainly in temperate and boreal regions of the northern hemisphere, chiefly in mountainous regions [1]. The literature data on phytochemical and biological investigations of the genus of Abies revealed that up to now, 277 compounds were isolated from 19 plants of Abies species. The chemical constituents are mostly terpenoids, flavonoids, and lignans, together with minor constituents of phenols, steroids, and others. The crude extracts and metabolites have been found to possess various bioactivities, including insect juvenile hormone, antitumor, antimicrobial, antiulcerogenic, antiinflammatory, antihypertensive, antitussive, and CNS (central nervous system) activities [2]. Abies pindrow Royle, commonly known as west Himalayan fir, is a large evergreen tree growing up to 40–60 m tall with a trunk diameter of up to 2–2.5 m. It has a conical crown with level branches. In Pakistan, Abies pindrow Royle, known as partal or palundar, is widely distributed at elevations between 2000 and 3000 m throughout the western Himalayas from Afghanistan to Nepal [3]. Pindrow species of Abies is regarded as carminative, stomachic, astringent, expectorant, tonic, antispasmodic, and antiperiodic [4]. Phytochemical studies of the species resulted in the isolation of glucopyranoside, hydroxyflavanone, chalcone glycoside, bioflavonoids, flavonoids and pindrolactone [5], and pentacyclic triterpenoids [6]. Different extracts from the leaves of Abies pindrow Royle exhibited anti-inflammatory, analgesic, and hypnotic activities in rats, attenuated swim stress in mice, and produced hypotension in dogs. Abies pindrow Royle leaves also have an antiulcerogenic effect on the cold-restrained gastric ulcer model in rats [5]. A review of the literature revealed that no hydrocarbons have yet been reported from Abies pindrow Royle. We have previously reported the fatty acid composition of the ethanol extract of the leaves of Abies pindrow Royle. A total of 11 fatty acids, including eight saturated and three unsaturated, was characterized [4]. The present investigation of aerial part (leaves) of Abies pindrow Royle describes the occurrence of long chain hydrocarbons. The presence of these hydrocarbons is detected by GC-MS and supported by FTIR. A careful look at the fragmentation pattern in the mass spectral data reveals the presence of saturated and unsaturated hydrocarbons. These hydrocarbons have been reported for the first time from Abies pindrow Royle. The GC-MS of the hexane fraction revealed the presence of tricosane, eicosane, heneicosane, docosane, tetracosane, nonadecane, octadecane, 1-docosene, 1-octadecene, heptadecane, and 2,6,10,14-tetramethylhexadecane. The identity of these common hydrocarbons was made by comparison of these peaks with the standards by gas chromatography and confirmed by comparison of the fragmentation pattern with those of standard mass spectrum. FTIR analysis supported the structures of these hydrocarbons. The FTIR spectrum exhibits the diagnostic peaks relating to C-H stretching at 2956 cm–1, 2923 cm–1, and 2852 cm–1, C-H bending (scissoring) at 1465 cm–1, C-H methyl rocking at 1378 cm–1, and long-chain methyl rocking at 722.9 cm–1. These peaks verify the required data regarding the hydrocarbons. The GC-MS study of major peaks revealed the presence of straight-chain saturated hydrocarbons. It showed the presence of 11 compounds. The GC-MS pattern showed 11 major peaks along with small peaks. All major peaks were detected as hydrocarbons by GC-MS at different retention times.

Measurement and source identification of polycyclic aromatic hydrocarbons (PAHs) in the aerosol in Xi'an, China, by using automated column chromatography and applying positive matrix factorization (PMF)

In this study, we measured polycyclic aromatic hydrocarbons (PAHs) in aerosols in Xi'an, China from 2005 to 2007, by using a modified Soxhlet extraction followed by a clean-up procedure using automated column chromatography followed by HPLC/fluorescence detection. The sources of PAHs were apportioned by using the positive matrix factorization (PMF) method. The PM10 concentration in winter (161.1±66.4μgm−3, n=242) was 1.5 times higher than that in summer (110.9±34.7μgm−3, n=248). ΣPAH concentrations, which are the sum of the concentrations of all detected PAHs, in winter (344.2±149.7ngm−3, n=45) was 2.5 times higher than that in summer (136.7±56.7ngm−3, n=24) in this study. These strong seasonal variations in atmospheric PAH concentration are possibly due to coal combustion for residential heating. According to the source apportionment with PMF method in this study, the major sources of PAHs in Xi'an are categorized as (1) mobile sources such as vehicle exhaust that constantly contribute to PAH pollution, and (2) stationary sources such as coal combustion that have a large contribution to PAH pollution in winter.

High Resolution PTR-TOF: Quantification and Formula Confirmation of VOC in Real Time

We present the unprecedented capability to identify and quantify volatile organic compounds (VOCs) by means of proton transfer reaction time-of-flight (PTR-TOF) mass spectrometry on-line with high time resolution. A mass resolving power of 4000-5000 and a mass accuracy of 2.5 ppm allow for the unambiguous sum-formula identification of hydrocarbons (HCs) and oxygenated VOCs (OVOCs). Test masses measured over an 11-wk period are very precise (SD < 3.4 ppm) and the mass resolving power shows good stability (SD < 5%). Based on a 1 min time resolution, we demonstrate a detection limit in the low pptv range featuring a dynamic range of six orders of magnitude. Sub-ppbv VOC concentrations are analyzed within a second; sub-pptv detection limits are achieved within a few tens of minutes. We present a thorough characterization of our recently developed PTR-TOF system and address application fields for the new instrument.

Quantification and Source Identification of Polycyclic Aromatic Hydrocarbons in Core Sediments from Sundarban Mangrove Wetland, India

The distribution and potential sources of 16 polycyclic aromatic hydrocarbons (PAHs) in sediment cores (<63 microm particle size) of the Sundarban mangrove wetland, northeastern coast of Bay of Bengal (India), were investigated by gas chromatography coupled to mass spectrometry. The total concentrations of 16 PAHs ( summation operator(16)PAHs) ranged from 132 to 2938 ng/g, with a mean of 634 ng/g, and the sum of 10 out of 16 priority PAHs ( summation operator(10)PAH) varied from 123 to 2441 ng/g, with a mean of 555 ng/g, and the 5 carcinogenic PAHs (benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, and dibenz[a,h]anthracene) accounted for 68-73% of the priority PAHs. Maximum concentrations of the sediment core were obtained at subsoil depth of 12-16 cm. The prevalence of four to six aromatic ring PAHs and cross-plots of specific isomer ratios such as phenanthrene/anthracene, fluoranthene/pyrene, and methylphenanthrenes/phenanthrene suggested the predominance of wood and coal combustion sources, the atmospheric deposition, and surface runoff to be the major transport pathways. A good correlation existed between the benzo[a]pyrene level and the total PAH concentrations, making this compound a potential molecular marker for PAH pollution. Total TEQ (S) (carc) values calculated for samples varied from 6.95 ng/g TEQ (S) (carc) to 119 ng/g TEQ (S) (carc) , with an average of 59 ng/g dry weight TEQ (S) (carc) . The baseline data can be used for regular monitoring, considering the industrial and agricultural growth around this coastal environment.

Characterization and Source Identification of PM10-bound Polycyclic Aromatic Hydrocarbons in Urban Air of Tianjin, China

PM10 samples were collected at six sampling sites in city center of Tianjin from April 2008 to January 2009. The concentrations of 17 selected polycyclic aromatic hydrocarbons (PAHs) in PM10 were quantified. Spatial and seasonal variations of PAHs were characterized. The dominant PAHs in PM10 samples were fluoranthene, pyrene, benz[a]anthracene, phenanthrene, chrysene, benzo[b]fluoranthene, anthracene, indeno[1,2,3-cd]pyrene and benzo[a]pyrene, accounting for above 85% of total PAHs. The total PAHs concentrations of the six sampling sites ranged from 23.4 to 513 ng/m3. Spatial variations were predominantly due to the different strengths of source emission. The total PAHs concentrations at Dongli Monitoring Station (DL) site and Beichen Science and Technology Park (BC) site were higher than those at other four sites in heating period, while those at Meijiang community (MJ) site and Beichen Science and Technology Park (BC) site were higher in no-heating period. Higher PAHs concentrations during heating period and lower concentrations during no-heating period were observed at the six sampling sites, which may be caused by the stronger emissions from stationary combustion sources in heating period and the quicker air dispersion, washout effects, photo-degradation and higher percentage in the air in vapor phase in no-heating period. The PAHs concentrations in gaseous phase were predicted with gas/particle partition model, and the BaP and BaP equivalency results indicated that the health risk of gas and particle phase PAHs to human in Tianjin were higher than that in other cities. The contributions from potential sources to PAHs in PM10 were estimated by the diagnostic ratios between PAHs and principal component analysis (PCA). In whole sampling period, coal combustion was found to the predominant contributor of PM10-bound PAHs, followed by vehicles emission and wood combustion.

Identification of petroleum hydrocarbons using a reduced number of PAHs selected by Procrustes rotation

Identifying petroleum-related products released into the environment is a complex and difficult task. To achieve this, polycyclic aromatic hydrocarbons (PAHs) are of outstanding importance nowadays. Despite traditional quantitative fingerprinting uses straightforward univariate statistical analyses to differentiate among oils and to assess their sources, a multivariate strategy based on Procrustes rotation (PR) was applied in this paper. The aim of PR is to select a reduced subset of PAHs still capable of performing a satisfactory identification of petroleum-related hydrocarbons. PR selected two subsets of three (C2-naphthalene, C2-dibenzothiophene and C2-phenanthrene) and five (C1-decahidronaphthalene, naphthalene, C2-phenanthrene, C3-phenanthrene and C2-fluoranthene) PAHs for each of the two datasets studied here. The classification abilities of each subset of PAHs were tested using principal components analysis, hierarchical cluster analysis and Kohonen neural networks and it was demonstrated that they unraveled the same patterns as the overall set of PAHs.

Chlorination for efficient identification of polycyclic aromatic hydrocarbons by liquid chromatography–mass spectrometry

Utilizing liquid chromatography-mass spectrometry (LC-MS) for identification of polycyclic aromatic hydrocarbons (PAHs) has long been underrated, as the sensitivity for determination of PAHs directly by MS is very poor. In the present work a chlorination method for high-sensitive determination of PAHs by LC-MS is discussed. This method includes two steps: (1) chlorination of PAHs by the BMC method; (2) determination of the chlorinated PAHs by LC-MS. Interfaced by atmospheric pressure chemical ionization in negative ion mode, five representative perchlorinated PAHs producing from the languidly detectable parent PAHs (naphthalene C(10)H(8), acenaphthene C(12)H(10), phenanthrene C(14)H(10), pyrene C(16)H(10) and fluoranthene C(16)H(10)) have been LC-MS characterized in high sensitivity with determination limits in 10(-9)g/mL level. In addition, molecular compositions and polycyclic carbon-frameworks of unknown PAHs can be identified according to the isotopic pattern of the chloro-derivatives ions in the corresponding mass spectra. Our experiments demonstrate that the proposed chlorination-involving LC-MS method is efficient for the PAHs analysis, for example, in soot and soil samples.

Identification of polycyclic aromatic hydrocarbons in unleaded petrol and diesel exhaust emission

Inhalation of emissions from petrol and diesel exhaust particulates is associated with potentially severe biological effects. In the present study, polycyclic aromatic hydrocarbons (PAHs) were identified from smokes released by the automobile exhaust from petrol and diesel. Intensive sampling of unleaded petrol and diesel exhaust were done by using 800-cm(3) motor car and 3,455-cm(3) vehicle, respectively. The particulate phase of exhaust was collected on Whatman filter paper. Particulate matters were extracted from filter paper by using Soxhlet. PAHs were identified from particulate matter by reverse phase high performance liquid chromatography using C(18) column. A total of 14 PAHs were identified in petrol and 13 in case of diesel sample after comparing to standard samples for PAH estimation. These inhalable PAHs released from diesel and petrol exhaust are known to possess mutagenic and carcinogenic activity, which may present a potential risk for the health of inhabitants.

Characterization and Identification of Petroleum Hydrocarbons and Biomarkers by GC-FTIR and GC-MS

Identification of petroleum hydrocarbons from crude and distilled oils by GC-MS is well known. The distilled crude and oils contain specific group of hydrocarbons are known as biomarkers bearing the information of their geographical source or origin and the geological past. These are diamondoids (adamantanes, diadamantanes, terpanes, steranes, sesquiterpanes, hopanes, norhopanes, etc.). The present article describes the identification of hydrocarbons using their IR spectra in the molecular fingerprinting region where every molecule shows its unique and characteristic individual vibrational frequencies. GC-FTIR spectrum of each of the individual components present in distilled oils was identified by proper standard library matching with the spectrum of the individual component. The GC-MS profiles of the biomarkers of different light and middle distilled fine products of samples from three leading oil companies, namely Indian Oil Corporation (IOC), Indo-Burma Petroleum (IBP), and Bharat Petroleum Corporation (BPC), differ from each other, indicating the variation of the sources of the crudes used by the companies. But nothing specific can be said about the origin of crudes from this limited data.