Identification Of Hydrocarbons Research Articles

Application of alternating trilinear decomposition-assisted multivariate curve resolution to gas chromatography-mass spectrometric data for the quantification of polycyclic aromatic hydrocarbons in aerosols.

For the first time, alternating trilinear decomposition-assisted multivariate curve resolution (ATLD-MCR) was applied to analyse complex gas chromatography–mass spectrometric (GC-MS) data with severe baseline drifts, serious co-elution peaks and slight retention time shifts for the simultaneous identification and quantification of polycyclic aromatic hydrocarbons (PAHs) in aerosols. It was also compared with the classic multivariate curve resolution-alternating least-squares (MCR-ALS) and the GC-MS-based external standard method. In validation samples, average recoveries of five PAHs were within the range from (96.2 ± 6.8)% to (106.5 ± 4.1)% for ATLD-MCR, near to the results of MCR-ALS ((98.0 ± 1.5)% to (106.7 ± 4.3)%). In aerosol samples, the concentrations of pyrene provided by ATLD-MCR were not significantly different from those of MCR-ALS. The other four PAHs including chrysene, benzo[a]anthracene, fluoranthene and benzo[b]fluoranthene were not detected by ATLD-MCR and the GC-MS-based external standard method. The results of figures of merit further demonstrated that ATLD-MCR achieved high sensitivities (8.9 × 104 to 1.7 × 106 mAU ml µg−1) and low limits of detection (0.003 to 0.087 µg ml−1), which were better than or similar to MCR-ALS, presenting a great choice to deal with complex GC-MS data for the simultaneous determination of targeted PAHs in aerosols.

Emission characteristics and source identification of polycyclic aromatic hydrocarbons (PAHs) from used mineral oil combustion

Presently, the characteristic of hazardous polycyclic aromatic hydrocarbons (PAHs) emission from used mineral oil (UMO) combustion in the industrial scenario is poorly explored and elucidated. In this work, the emission characteristic and source identification of 16 PAHs emitted from atomization combustion of five kinds of UMO and two types of base oil were investigated. The influence of temperature (600–1000 °C) and excess air ratio (0.8–1.4) on PAHs emission were assessed. Regarding emission factor (EF) and distribution of specific PAHs, high similarities were observed for combustion of different UMOs. EFs of PAHs were within the range between 61.58 µg g−1 and 105.03 µg g−1 (800 °C, stoichiometric air). The 2- and 3-ring PAHs made up more than 70% of the total PAHs in the flue gas, with the naphthalene accounting for 30.7%–48.1%. Over 80% of the emitted PAHs was partitioned into gas phase. The EFs of PAHs showed a parabolic trend with temperature and peaked at 800 °C. Higher temperature can decrease the total PAHs emission but lead to the enrichment of high-ring PAHs. Adequate air supply can efficiently reduce PAHs formation, especially at high temperatures. More than 95% of the total PAHs was eliminated when the excess air ratio was increased from 0.8 to 1.4 at 900 °C. Temperature influence on PAHs emission can be greatly weakened in high excess air level. The PAHs emitted from UMO combustion were randomly irrelevant to the original PAHs in UMO.

Occurrence, source identification, and ecological risk assessment of polycyclic aromatic hydrocarbons in sediments of the Pearl River Delta, China

The pollution characteristics, sources, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in surface sediment samples from the river networks and outlets of the Pearl River Delta (PRD) were investigated. The total PAH concentrations were in the range of 69.1–1297 ng g−1 in river networks and 56.6–617 ng g−1 in river outlets. The results of source identification showed that PAHs in sediments were mainly derived from combined sources of coke tar and liquid fossil fuel combustion, coal/wood combustion, and petroleum contamination. The ecological risks of PAHs were evaluated based on sediment quality guidelines (SQG), mean probable effects levels quotient values (PEL-Q), and the toxicity equivalence factor (TEQBaP) method. The ecological risks of PAHs in sediments were at moderate levels in the Pearl River Delta. Although no high risk was found, regular and continuous monitoring of PAHs in sediments needs to be performed.

Photonic sensor systems for the identification of hydrocarbons and crude oils in static and flow conditions

Identification of hydrocarbons and crude oils is typically carried out with samples that, taken from natural sources or refineries, must be brought to the laboratory for their analysis with rather sophisticated instruments. Alternatively, “in situ” procedures have been also developed for this purpose. In this work, we propose the use of a series of several sensor systems based on photonic transducers in the form of chips for the identification and classification of crude oils and hydrocarbons through the determination of their refractive index in the visible and absorption in the near infrared regions of the electromagnetic spectrum. Two of the photonic transducers rely on modifications of a Bragg microcavity and they monitor the changes in visible light interference phenomena that occur in response to the variation of the refractive index of oils. The third one, in the form of a dielectric mirror, monitors the near infrared absorption of crude oils and hydrocarbons through the recording of a transflectance spectrum. The capacity of these transducers for crude oil identification is proved by the analysis of a series of oils and distilled fractions that have been properly identified and classified as a function of their density and partition of long hydrocarbon chains. The three photonic transducers are operated with optical fibers and can be used in static and dynamic modes, this latter under conditions that are especially well-suited for “in-situ” analysis of oil streams in real facilities. The proved resistance of the chips to high pressure and temperature conditions supports their suitability to withstand harsh working environments as those existing in extraction wells.

Temporal Variations and Source Identification of Polycyclic Aromatic Hydrocarbons (PAHs) in Rainwater Collected in a Semi-Urban Area within an Industrial Area in Turkey

The purpose of this study was to investigate temporal variations and to identify source of polycyclic aromatic hydrocarbons (PAHs) between October 2019 and September 2020 in forty-one rainwater samples collected in a semi-urban area of Gebze, Kocaeli which is highly affected from by industrial pollution due to the existence of many organized industrial zones. Sampling was done for every rainy day during sampling period and the meteorological data (temperature, humidity, wind speed etc.) for sampling days were recorded. The collection of PAHs from the rainwater samples was done by using the SPE C18 cartridge with the help of hexane-acetone mixture (v/v) and gas chromatography system-triple quadrupole mass spectrometry (GC-MS/MS) was used for the measurement of PAHs. The calibration curves of PAHs, which presented greater than 0.995 of r2 values, possessed quite good linearity. Limit of detection (LOD) values for all PAHs were in the range of 0.10 ng/L and 0.29 ng/L, and the ranges of limit of quantification (LOQ) were from 0.32 ng/L to 0.98 ng/L. All PAHs reached their highest concentrations during the cold season, with a significant decrease in the concentrations from the cold months to the hot months with a few exceptions. Monthly mean total PAH concentrations ranged from 135.0 ng/L (in July) to 401.6 ng/L (in January). The compounds with the highest contribution to the total PAH concentration were naphthalene (28.20%), phenanthrene (16.84%), fluoranthene (12.44%), pyrene (9.31%) and benzo(b)fluoranthene (6.17%). The fraction of benz(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenz(a,h)anthracene, indeno(1,2,3-c,d)pyrene defined by the competent authorities as high carcinogenic effects on humans to the total PAH concentration in rainwater samples were only 16.93%. When the results obtained from the ratios of different PAH compounds in diagnostic analysis (Fluoranthene/Pyrene ratio: 1.31; Fluoranthene/Fluoranthene + Pyrene ratio: 0.58 and Phenantherene/Phenanthrene + Anthracene ratio varied from 0.92 to 0.95) were evaluated together, all these ratios indicated the dominance of coal combustion in the source of PAHs. The results of benz(a)anthracene, benzo(k)fluoranthene, dibenz(a,h)anthracene, fluorene, naphthalene and pyrene were frequently lower than the previous studies in literature.

Continuous streamline trajectories on complex grids

Streamlines have been used for reservoir modeling and flow visualization in the petroleum industry and in computational fluid dynamics. When applied to the calculation of volumetric sweep and the identification of by-passed hydrocarbons for improved oil recovery, it is important that the velocity models that are used to trace trajectories across the cells of a grid are flux conservative. As such, the requirements on their tracing may be more stringent than in other disciplines. Flux conservation is also important at faults, at locally refined or coarsened embedded grid boundaries, and within unstructured grids, where the modeling of flow within a cell may not be consistent with the connection fluxes from adjacent cells. In such cases, additional degrees of freedom must be introduced to satisfy flux conservation. In this study, we introduce a flux conservative conforming cell face local boundary layer construction to resolve these inconsistencies. In contrast, solutions that rely upon spatial continuity of streamlines between elements are shown to not be flux conservative when these inconsistencies are present. The use of flux conservative conforming elements also allows the solution to be developed in local isoparametric coordinates, without explicit reference to cell or connection geometry. The solution has been implemented for both 3D corner point and for 2.5D PEBI grids. In all cases we utilize the lowest order Raviart–Thomas zeroth order velocity model, for which the trajectories and transit times may be obtained analytically. The results are demonstrated on a sequence of increasingly complex type, sector and full-field model applications.

Genetic identification of hydrocarbons degrading bacteria isolated from oily sludge? and petroleum-contaminated soil in Basrah City, Iraq

Abstract. Aboud EM, Burghal AA, Laftah AH. 2021. Genetic identification of hydrocarbons degrading bacteria isolated from oily sludge? and petroleum-contaminated soil in Basrah City, Iraq. Biodiversitas 22: 1934-1939. Petroleum is a major problem for environmental pollution due to the extensive use, which can reach all parts of the environment. Contaminated environments are required to identify bacterial diversity that has a remarkable ability to tolerate and biodegrade toxic compounds. The process of oil degradation by microorganisms in their natural environment is affected by certain chemical, physical and biological conditions. Bioremediation techniques are powerful for removing oil pollution, which reflects the ability of microorganisms to destroy organic pollutants. In the current study, six bacterial isolates (S1-S6) were isolated from oil-contaminated soils. mineral salt medium (MSM) was used to carry out biodegradation, crude oil degradation was an evaluation by the gravimetric method. After two weeks of incubation showed S5 isolate the greatest efficiency in oil degradation 53.6%, S1 and S6 also gave good capability degradation (47.31% and 44.9%) respectively, while isolates S2 and S3 gave the lowest percentage. All isolates were identified by 16S rDNA amplicons as Pseudomonas stutzeri, Psychrobacter faecalis, Pseudomonas songnenensis, Bacillus cereus, Psychrobacter quanticus strain E9R, and Psychrobacter quanticus strain EA422 according to molecular identification. The current study indicated that hydrocarbon-degrading bacteria specially Psychrobacter can be used to clean soil from crude oil and other industrial discharges.

Species Identification and Effects of Aromatic Hydrocarbons on the Fluorescence Spectra of Different Oil Samples in Seawater

The identification of oil species and their characteristics in oil spills is particularly important for their efficient disposal. Since aromatic hydrocarbons (AHs) with various characteristics are the major fluorescent components of oils in seawater, they can be used to detect different oil species in seawater. Here, we developed a composition method using the fluorescence spectra of eight AH categories analyzed by gas chromatography-mass spectrometry (GC-MS) to evaluate the contribution of AHs to the total fluorescence of six different oil species. Qualitative and quantitative difference analysis of the experimental and composite fluorescence spectra was performed based on the redshift of the main peak position, the fluorescence intensity distance, and the generalized included angle cosine, while correlation analysis was used to establish the relationship between the different fluorescence spectral parameters and the American Petroleum Institute gravity and viscosity of the oil species. The fluorescence spectra recorded for heavy oil samples indicated a reduction in the fluorescence signal of fluorene series and an increase in the contribution of acenaphthene and pyrene series, indicating that the currently developed composition method by fluorescence spectroscopy combined with GC-MS can be used to distinguish and identify oil species in seawater samples.

Isolation and Identification of Hydrocarbons- Degrading Bacteria from Panteka Stream, Kaduna, Nigeria, and Assessment of their Potential for Bioremediation

Water bodies become hydrocarbon-polluted when petroleum and other toxic organic matters are discharged into them. Panteka, located in northern Kaduna, Nigeria, is home to Panteka market, which is an industrial hub where different kinds of automobile spare parts are sold and mechanic workshops are situated. The Panteka stream flows through an entry point at Rafin guza, through Panteka market and towards the National Eye Centre. The indiscriminate disposal of spent engine oils and the discharge of other untreated effluents from car servicing workshops into the Panteka stream can lead to hydrocarbon contamination. Consequently, there is a need to identify these hydrocarbons and determine the capability of bacteria isolated from the stream to degrade the hydrocarbon pollutants. Using the pour plate method, and Bushnell Haas agar supplemented with 1% used engine oil, five bacterial isolates with the potential to degrade hydrocarbons were identified as Streptococcus pnuemoniae, Klebsiella pneumoniae, Shigella dysenteriae, Streptococcus pyogenes and Salmonella enterica. Salmonella enterica was confirmed by 16S rRNA gene sequencing and Basic Local Alignment search tool (BLAST) with a similarity index of 99%. The ability of the bacterial isolates to tolerate the spent engine oil was determined by turbidi metry. The results show that all the five bacterial isolates were able to tolerate the 1% (v/v) concentration of the spent engine oil. The highest growth rates (O.D 0.565 and O.D 0.695) were obtained from the pure cultures of Streptococcus pyogenes and the mixed bacterial consortium, respectively. The potentials of the bacteria to degrade hydrocarbons in the stream was analysed using Gas Chromatography Flame Ionization Detector (GC-FID), and the results showed reduction of the Total Petroleum Hydrocarbon (TPH) content from 6,056 mg/ml to 100.17 mg/ml (98.3% degradation) after 28 days of treatment with the mixed bacterial culture. The hydrocarbon fractions degraded were n-Nonane, n-Decane, n-Undecane, n- Dodecane, n-Tridecane, n-Tetradecane, n-Heptadecane, Pristane, n-octadecane, Phytane, n-Eicosane, n-Tricosane, n-Tetracosane, n-Octacosane, n-Triacontane, n-Dotriacontane, n-Tritriacontane, n-Heptriacontane; while n-Pentadecane, n-Hexadecane, n-Nonadecane, n-Heneicosane, n-Docosane, n-Pentacosane, n-Hexacosane, n-Heptacosane, n-Nonacosane, n-Hentriacontane, n-Tetratriacontane, n-Pentatriacontane, and n-Hexatriacontane were not degraded. This study shows that these bacterial strains isolated from the Panteka stream have great potential for bioremediation of the hydrocarbons found in the stream.
 Keywords: Bioremediation, Panteka stream, Automobile workshop, Hydrocarbon pollution, Bacteria isolates

Spectroscopy and thermal studies of valsartan compounds with metals Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) in the solid state

Solid-state M-Val compounds were synthesized, where M stands for bivalent metals (Mn, Fe, Co, Ni, Cu, and Zn), and Val stands for valsartanate ion (C24H27N5O32−). The thermal and spectroscopic study of the compounds was performed using TG-DSC, FTIR, DRX, as well as the evolved gas analysis (EGA) by TG/DSC-FTIR. The thermoanalytical results showed information about the stoichiometry of the compounds (1:1), the degree of hydration, and thermal behavior. The EGA results allowed the identification of the aliphatic hydrocarbons, carbon monoxide, carbon dioxide, and ammonia for both Valsartan and metal compounds. The theoretical and experimental spectroscopic data suggested the possible modes of coordination of the ligand with the metal ions by coordinating bonding with the oxygen of the carboxylate and the tetrazole group's nitrogen. The association of Cu (II) and Co (II) metal ions with Val improves the antimicrobial activity against E. coli.

Identification and Quantification of Polycyclic Aromatic Hydrocarbons in Polyhydroxyalkanoates Produced from Mixed Microbial Cultures and Municipal Organic Wastes at Pilot Scale.

Polyhydroxyalkanoates (PHAs) are well-known biodegradable plastics produced by various bacterial strains, whose major drawback is constituted by the high cost of their synthesis. Producing PHAs from mixed microbial cultures and employing organic wastes as a carbon source allows us to both reduce cost and valorize available renewable resources, such as food waste and sewage sludge. However, different types of pollutants, originally contained in organic matrices, could persist into the final product, thus compromising their safety. In this work, the exploitation of municipal wastes for PHA production is evaluated from the environmental and health safety aspect by determining the presence of polycyclic aromatic hydrocarbons (PAHs) in both commercial and waste-based PHA samples. Quantification of PAHs by gas chromatography-mass spectrometry on 24 PHA samples obtained in different conditions showed very low contamination levels, in the range of ppb to a few ppm. Moreover, the contaminant content seems to be dependent on the type of PHA stabilization and extraction, but independent from the type of feedstock. Commercial PHA derived from crops, selected for comparison, showed PAH content comparable to that detected in PHAs derived from organic fraction of municipal solid waste. Although there is no specific regulation on PAH maximum levels in PHAs, detected concentrations were consistently lower than threshold limit values set by regulation and guidelines for similar materials and/or applications. This suggests that the use of organic waste as substrate for PHA production is safe for both the human health and the environment.

Contamination and Sources Identification of Polycyclic Aromatic Hydrocarbons in Water and Sediments of Annaba Bay Basin, Algeria

Annaba gulf is a coastal area (southwestern Mediterranean Sea) that receives large diffuse inputs from Fertial plant, Seybouse wadi and Boujemaâ wadi, which are influenced by anthropogenic activities. Wastewaters and surface waters and sediments from these sites were analyzed for Polycyclic Aromatic Hydrocarbons (16 PAHs) by using gas chromatography system operating with the flame ionizing detector (FID). Total PAHs ranged from 0.033 to 0.503 µg L–1 in water, and from 32.44 to 509.58 µg kg–1dw in sediments. In order to identify pollution emission sources of PAHs, three source identification techniques were used, including diagnostic ratios, Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA). The results show that the pollution originated mainly from pyrogenic inputs in water and sediments. Annaba Bay basin is contaminated mainly by heavy PAHs discards originated from domestic and industrial wastewaters and traffic emissions.

Chemical characterization, source identification and health risk assessment of polycyclic aromatic hydrocarbons in ambient particulate matter over central Indo-Gangetic Plain

Polycyclic aromatic hydrocarbons (PAHs) are the carcinogenic component of carbonaceous aerosols and the toxicity of PAHs depends on their molecular structure. PM2.5-bound PAHs concentration, their isomeric ratios and health impacts during wintertime (fog and non-fog episodes) are assessed at two heavily polluted sites (Allahabad and Kanpur) in central IGP (Indo-Gangetic plains) to better understand the spatial-temporal variability of PAHs as well as identification of their major sources. The highest contribution to PAH loading is reported from indeno (1,2,3-c,d) pyrene, benzo(g,h,i) perylene, benzo (b,j) fluoranthene and benzo (a) pyrene at the two sites during studied winter campaigns. Significantly higher contribution from 6-ring PAHs to total PAH concentration at Allahabad has been observed as compared to Kanpur. Moreover, lower PAHs concentration observed during dense fog episodes can be attributed to wet scavenging of aerosols by fog droplets. Isomeric ratios of PAHs indicated significant contribution from diesel engine exhaust at Allahabad and gasoline combustion at Kanpur. Substantial contribution from coal combustion and biomass burning emissions during wintertime over these sites was also observed. Estimation of health risk due to PAHs indicate potential health hazard to adults as well as children at both the sites. Furthermore, health risk observed due to carcinogenic metals (Cr(VI), Cd, Ni, As) and PAHs is nearly twice at Allahabad as compared to Kanpur. Diesel exhaust emissions (a dominant source of Cd and PAHs) appeared to be responsible for increased cancer risk at Allahabad. Whereas, higher Cr(VI) and PAHs concentration in the ambient aerosol is aggravating cancer risk at Kanpur.

Evaluation of a characterization method of Egyptian human mummy balms by chemometric treatments of infrared data

In the context where lengthy protocols are used to extract and to characterize each substance from mummification balms using techniques such as gas chromatography and mass spectrometry, this paper presents the evaluation of the efficiency of an original method to characterize mummification balms using the SIMPLISMA algorithm in infrared spectroscopy. This tool is a pure variable approach corresponding to the selection of calibration variables. This developed approach was combined with chemometric treatment (principal component analysis) to interpret the 47 Fourier Transform Infrared spectra of human mummies’ balms from Ancient Egypt. This treatment gave 6 pure spectra and their corresponding extracted concentration profiles. The first pure spectrum corresponded to residual species, and the second to the identification of polycyclic aromatic hydrocarbons, molecules which have a pyrolytic origin. The fourth pure spectrum corresponded to proteins which were characterized, and could be considered as markers of good conservation of individuals. The fifth pure spectrum characterized polysaccharides. Finally, two pure spectra showed the same natural substance, namely fat, which, on the one hand, was unaltered and, on the other hand, was degraded fatty matter. This fast, simple and non-destructive approach allowed the composition of each balm to be studied and their state of conservation/degradation to be characterized. This approach enabled the presence of proteins, polysaccharides and fatty matter or beeswax in different states of conservation/alteration in the studied balms to be characterized.

Geochemical Fingerprinting pf Oil-Impacted Soil and Water Samples In Some Selected Areas in the Niger Delta

Abstract With over 50 years of oil exploration and exploitation in the Niger Delta, there has been an increasing rate of environmental degradation due to hydrocarbon pollution. This study is aimed at tracing the sources of the oil spills and the distribution of pollutants in selected communities in the Niger Delta using geo-chemical techniques. A total of sixteen samples made up of ten crude oil-impacted soil samples taken at a depth of 30 cm and six water samples (two from boreholes, two from burrow pits and two from surface water – one from a river and the other from rain harvest as control) were collected. The identification and quantification of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) in the samples were performed with an Agilent 7890B gas chromatography flame ionisation detector (GCFID). The AHs including pristane and phytane, together with seventeen priority PAHs, were identified. The values of AHs and PAHs in the water samples ranged from 0.13 mg/l to 5.78 mg/l and 0.09 mg/l to 1.109 mg/l, respectively, while that for the soil samples ranged from 22.52 mg/kg to 929.44 mg/kg and 10.544 mg/kg to 16.879 mg/kg, respectively.

Detection and identification of polyaromatic hydrocarbons (PAHs) contamination in soil using intrinsic fluorescence.

Polyaromatic hydrocarbons (PAHs), such as pyrene, benzo[a]pyrene, phenanthrene, and anthracene induce toxic, carcinogenic, and mutagenic effects on living organisms and are considered as primary pollutants. Traditional methods for their identification are often laborious and time-consuming and do not account for the heterogeneous nature of their distribution. Here we present confocal microscopy as a rapid and accurate technique for direct analysis of PAHs in soil samples without the complexity of sample pre-processing which might delay results for several days. The method uses the intrinsic fluorescence of PAHs for detection and their emission spectra for the identification of different PAHs. A clear difference was observed in the fluorescence spectral properties of phenanthrene, pyrene and naphthalene in real-time environmental samples. The post-processing of confocal scans obtained in the detection stage of PAHs was completed through the application of ImageJ software. Intrinsic fluorescence-based detections of PAHs may open new avenues in terms of rapid detection and identification of PAHs in heterogeneous complex soil samples.

On-site separation and identification of polycyclic aromatic hydrocarbons from edible oil by TLC-SERS on diatomite photonic biosilica plate

The accumulated polycyclic aromatic hydrocarbons (PAHs) in edible oil can bring serious health concerns because of their carcinogenic features. PAHs could accumulate in edible oil from contaminated environment or food stuff. In this study, the combination uses of on-site thin layer chromatography and surface enhanced Raman scattering (SERS) spectroscopy has been successfully displayed to identify PAHs from edible oil samples. Diatomite which is a kind of porous biosilica was used to construct stationary phase on TLC plate, the photonic crystal feature of diatomite is beneficial for SERS enhancement. The highly-porous stationary phase composed of porous diatomite with void shell structure could promote mobile phase interaction with the stationary phase, which leading to improved mass transfer, uniformity and analyte resolution compare with the conventional silica gel plate. The edible oil (1 µL) was directly applied to the diatomite plate without pretreatment, and subjected to TLC separation. The polarity of target analytes was calculated for eluent optimization, on which four compounds of PAHs(benzo[a]pyrene, pyrene, anthracene and indeno[1,2,3-cd] pyrene) were successfully separated by using hexane/chloroform (15/1, v/v) as eluent, including compounds with similar polarity(benzo[a]pyrene 0.0477, indeno[1,2,3-cd] pyrene 0.6545, pyrene and anthracene are 0). 2 µL of Au colloid at 2.4 × 10−7 M were transferred onto the diatomite plate for the SERS measurement. The limit of detection was found to be nearly at 1 ppm. The obtained results can easily identify the four compounds of PAHs in edible oil by their own characteristic Raman peaks. This proposed method provides a simple, instant and effective strategy for on-site identification PAHs from food samples.

Aliphatic Hydrocarbons Extraction from Oily Sludge using Kerosene

The National Petroleum Refinery of Cameroon is a crude oil refining company that generates large quantity of oily sludge. The extraction, identification and quantification of aliphatic hydrocarbons that can be recovered from oily sludge were assessed. The extraction was conducted following an experimental design and the distribution of the aliphatic hydrocarbons of the sludge was realized by using a simple gas chromatographic method. The extraction results showed that all the factors have positive effect on the extraction. It was also found that the highest concentration of 127992 ppm was obtained under experimental conditions of Ratio = 6:1, Temperature = 40°C, Contact time = 90 min.

Aliphatic Hydrocarbons Extraction from Oily Sludge using Kerosene

The National Petroleum Refinery of Cameroon is a crude oil refining company that generates large quantity of oily sludge. The extraction, identification and quantification of aliphatic hydrocarbons that can be recovered from oily sludge were assessed. The extraction was conducted following an experimental design and the distribution of the aliphatic hydrocarbons of the sludge was realized by using a simple gas chromatographic method. The extraction results showed that all the factors have positive effect on the extraction. It was also found that the highest concentration of 127992 ppm was obtained under experimental conditions of Ratio = 6:1, Temperature = 40°C, Contact time = 90 min.

Unraveling chemical structure of laminar premixed tetralin flames at low pressure with photoionization mass spectrometry and kinetic modeling

AbstractThis work reports an investigation on laminar premixed flames of tetralin at 30 Torr and equivalence ratios of 0.7 and 1.7. Measurements of the chemical structure including identification and mole fraction measurements of free radicals, isomers, and polycyclic aromatic hydrocarbons (PAHs) were performed using synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV‐PIMS). A kinetic model with 296 species and 1 577 reactions was developed and validated against the flame chemical structure data measured in this work. Modeling analysis reveals the key reaction pathways in tetralin decomposition and PAHs formation. The H‐atom abstraction reactions by H, O, and OH are found to control the consumption of tetralin in the lean flame, while those by H play the dominant role in the rich flame. Indene and naphthalene have very high concentration levels in the rich tetralin flame due to the existence of direct formation pathways from the decomposition of tetralin. The two bicyclic PAHs and their radicals play significant roles in the PAHs growth process of tetralin combustion, which results in the high sooting tendency of tetralin compared to those of alkylbenzenes with smaller or same carbon atom numbers.