Levels of Some Persistent Organic Pollutants (PCBs and PAHs) in Jordanian Oil Shale Ash after Direct Heating at Different Temperature Ranges

The levels of 13 polycyclic aromatic hydrocarbons (PAHs) and 12 polychlorinated biphenyls (PCBs) were studied in oil shale ash samples gathered after heating oil shale samples collected from major deposit sites in Jordan. All analyses were carried out using GC/MS instrument. The results showed that the total concentration of the studied polycyclic aromatic hydrocarbon (PAHs) was the highest (75.99–317.53 μg /kg) at the lowest temperature range (200–400°C) and it decreased as the temperature increased. For the heating temperature range 400–600°C the concentrations were all decreased to below the limit of quantification while none of the samples contained any of the studied PAHs at the highest temperature range 600–800°C. While all the analyzed samples did not contain any of the studied 13 compounds of PCBs at different temperature ranges.

Recoveries of PAHs and PCBs were found between 82–106% and 91–114%, respectively. Precision of the analytical method for both PAHs and PCBs, calculated as relative standard deviation (RSD), ranged from 0.95–7.08% and 0.78–9.03%, respectively. The limit of detection values for PAHs and PCBs were between 0.006–0.070 μg/kg and 0.149–0.330 μg/kg, respectively.

The total estimated cancer risks of exposure to PAHs in the soil samples were ranged from 9.13 × 10^?7 to 2.15 × 10^?6. By multiplying these numbers of cancer risks of exposure to oil shale ash sample-PAHs by 10⁶, it is possible to determine the maximum theoretical number of cancer cases per million of people. The maximum estimated cancer risks cases determined in this study (2 out of 1 million) are well within the acceptable range of excess cancer risk specified by the US Environmental Protection Agency.     

Sourcing of Fossil Fuel-Derived PAH in the Environment

To investigate the effects of domestic coal burning on the distribution and isotopic composition of environmental PAH, a series of soil samples were collected in a coal-burning village nearby Glasgow, UK. Analyses showed that, typically, PAHs in the Lochwinnoch village samples were isotopically heavy having δ¹³C values close to ?25‰ that are consistent with the PAHs emanating from coal burning. It was also noted, however, that alkylated PAHs would appear to be more prominent in soot from coal fires than in the samples collected in Lochwinnoch where domestic combustion was determined to be the major source. Therefore, to address the possibility that parent PAHs may survive in soils preferentially, two weathering experiments have commenced using a low temperature coal carbonisation tar from the Coalite process. Initial results have shown that after as little as 80 days weathering period, parent PAHs, particularly fluoranthene and pyrene, become more prominent than alkylated species, suggesting that these compounds may survive oxidation/weathering to a greater extent than their alkylated counterparts.     

Resolving coal and petroleum-derived polycyclic aromatic hydrocarbons (PAHs) in some contaminated land samples using compound-specific stable carbon isotope ratio measurements in conjunction with molecular fingerprints☆

It has been established previously [Anal. Commun. 33 (1996) 331; Analyst 123 (1998) 1519; Org. Geochem. 30 (1999) 881; Environ. Sci. Technol. 34 (2000) 4684] that, for thermal conversion regimes where volatiles survive to a significant degree (e.g. low and high temperature carbonisation, domestic combustion), the stable carbon isotopic signatures of polycyclic aromatic hydrocarbons (PAHs) are similar to those of the parent coals (ca. −25‰, cf. −23.5‰ for the coals). This information has been used to unambiguously identify coal-derived PAHs in contaminated land sites. Aromatic hydrocarbons in a number of samples analysed from a former foundry site at Mansfield displayed variable compositions with those containing predominately alkylated benzenes and naphthalenes having carbon stable isotopic ratios in the range of −28 to −30‰, typical of transport fuels. The aliphatic hydrocarbon distributions confirmed the petroleum origin and indicated that the oil had also been biodegraded. Less negative (enriched in ¹³C, −25 to −26‰) isotopic profiles were obtained for the fractions rich in 3–6 ring parent PAHs, indicating a significant input from coal utilisation. Separating the aromatic by ring size enabled the coal-derived 3–6 ring PAHs to be identified in samples where petroleum-derived alkylated benzenes and naphthalenes dominated. A similar situation to this with only a small input from coal-derived PAHs was found for a soil heavily contaminated with diesel fuel from the Motherwell area. Carbon stable isotopic data taken in conjunction with PAH distributions indicate that the coal tar contaminating an area of Glasgow Green, which was believed to be dumped during the Second World War and was unearthed recently, probably originated from a high temperature coking plant as opposed to a gas works, as indicated by the isotopic signatures of the distributions of PAHs.     

Levels of 15 + 1 EU Priority Polycyclic Aromatic Hydrocarbons in Different Edible Oils Available in the Syrian Market

ABSTRACT

The levels of 15 + 1 EU priority polycyclic aromatic hydrocarbons (15 + 1 EU PAHs) have been determined in different edible oils (extra virgin olive oil, virgin olive oil, sunflower oil, corn oil, and soybean oil) available in the Syrian market. The samples have been prepared by donor–acceptor complex chromatography and subsequently characterized by high-pressure liquid chromatography coupled with fluorescence and ultraviolet detection for quantification purposes. Variable levels of contamination have been found within different kinds of edible oil samples, and only chrysene has been detected in all the studied samples. Moreover, the mean total sum of 15 + 1 EU PAHs has shown variation from 29.8 µg/kg (corn oil) to 63.7 µg/kg (virgin olive oil). A total of 11 samples out of 38 samples (28.9%) have not fulfilled the European Union (EU) food law requirements. Nine samples have exceeded the EU legislation limit of benzo[a]pyrene (BaP) (2 µg/kg) and only two samples have exceeded the EU legislation limit of PAH4 (10 µg/kg) and had acceptable level of BaP. Finally, the mean and maximum dietary exposures of PAHs through consumption of edible oils have been estimated.     

LONG TERM MONITORING OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IN BLUE MUSSELS (Mytilus edulis) FROM A REMOTE SCOTTISH LOCATION

Farmed mussels have been collected on a monthly basis since 1999 from a remote site on the west coast of Scotland for polycyclic aromatic hydrocarbon (PAHs) analysis with the aim of establishing background concentrations as a benchmark against which to assess any environmental incident. Total PAH (2- to 6-ring parent and alkylated) concentrations ranged from 12.5 to 151.2 μg kg^?1 wet weight. Seasonal trends were evident with concentrations being significantly higher for samples collected between November and March compared to those collected between April and October. By taking the median of medians for each of these time periods two background concentrations are suggested for the total PAH concentrations (2- to 6-ring PAHs parent and alkylated); for April to October: 31.2 μg kg^?1 wet weight and for November to March: 62.9 μg kg^?1 wet weight. Individual PAH concentrations were mainly below the OSPAR Background Assessment Concentrations (BACs), where they are specified, and were only exceeded for the heavier 4- and 5-ring PAHs (fluoranthene, pyrene, benz[a]anthracene and benzo[a]pyrene) in samples collected between November and March. Differences were also seen in the PAH profiles with season. Mussels collected between November and March had a higher proportion of the heavier PAHs compared to mussels collected in the summer and autumn.     

Changes of Tocopherols and Phospholipids during Heating of Low-Erucic Rapeseed Oil at Temperature Similar to Fritting

Rapeseed oil – crude and refined – and the fraction of acylglycerols isolated from these oils were added to natural amounts of tocopherols or phospholipids and were heated in conditions similar to fritting during 30 hours. Maximum formation of dimers amounted to 24% of initial quantity of tocopherols. In the samples heated at 170°C dimers occurred incidentally, only in model systems of acylglycerols with addition of tocopherols and mainly with big concentration of alphatocopherol. Also the accelerating influence of natural oil components on tocopherol decrease at 170°C was observed.     

The thermal conductivity of oils sands

Measurements have been made of the effective thermal conductivity of some samples of Athabasca oil sands using a steady state method over the temperature range 20°C – 120°C. The bitumen content of the samples was altered from its natural value by mixing with additional sand and the resulting values of the thermal conductivity were found to increase with increasing the oil content. Moreover, the effective thermal conductivity values were found to decrease with increasing temperature.     

Stability of Polycyclic Aromatic Hydrocarbons in Frozen Mussel Tissue

The stability of polycyclic aromatic hydrocarbons (PAHs) in frozen mussel tissue (stored at -80 °C and -120 °C was assessed by analyzing samples of SRM 1974 and SRM 1974a, Organics in Mussel Tissue (Mytilus edulis), since the initial certification analyses. Results of analyses of SRM 1974 and SRM 1974a after 10 years and 6 years of storage, respectively, indicate that the PAH concentrations have not changed. Comparison of results from the analyses of frozen versus freeze-dried mussel tissue samples indicate significant losses of the more volatile PAH such as naphthalene and methylnaphthalenes during the freeze-drying process.     

污水污泥裂解油中多环芳烃的分析

引言在一些发达国家,污水污泥热裂解技术作为能量回收型污泥处理技术已经进入商业应用阶段,其裂解产生的液体燃料能直接用于柴油机车,并与石油提炼厂生产出来的石油低级馏出液相似     

Compositional Changes of Hydrocarbons of Residual Oil in Contaminated Soil During Ozonation

Ozonation is an effective method to remove recalcitrant weathered oil in contaminated soil. The purpose of this study was to characterize the compositional changes of hydrocarbons in residual oil during ozonation. A bioremediated soil containing residual oil was ozonated for up to 15 h. A total of 102 compounds in the residual oil were analyzed by GC/MS and 36 diagnostic ratios (DRs) were calculated based on quantitative or semi-quantitative results in order to evaluate the susceptibility of the residual oil compositions to ozonation and the effects of ozonation on the fingerprint profile of the residual oil. The total ozonation removal rates were in the following order: triaromatic steranes (TAS) > steranes, polycyclic aromatic hydrocarbons, terpanes > alkanes. Ozone kept the fingerprints of n-alkanes, C₂₇- to C₃₄-terpanes, steranes and TAS, separately. Branched alkanes (i.e., pristane and phytane) showed a higher removal rate than n-alkanes. Ozone reactivity of PAHs depended on the number of rings, presence of heteroatoms and level of alkylation. Four- to six-ring PAHs and PAHs with a high level of alkylation showed higher reactivity, while dibenzothiophene and alkylated dibenzothiophenes were found to be resistant to ozonation. Some of the biomarker source ratios remained stable and could still be used for source identification even after some of the biomarkers were removed by >90% by ozonation.     

Time to Say Goodbye to the 16 EPA PAHs? Toward an Up-to-Date Use of PACs for Environmental Purposes

The 16 EPA PAHs have played an exceptionally large role above all in environmental and analytical sciences in the last 40 years, but now there are good reasons to question their utility in many circumstances even though their use is so established and comfortable. Here we review the reasons why the list has been so successful and why sometimes it is seen as less relevant. Three groups of polycyclic aromatic compounds (PAC) are missing: larger and highly relevant PAHs, alkylated PACs, and compounds containing heteroatoms. Attempts to improve the situation for certain matrixes are known and here: (1) an updated list of PAHs (including the 16 EPA PAHs) for the evaluation of the toxicity in the environment (40 EnvPAHs); (2) a list of 23 NSO-heterocyclic compounds and 6 heterocyclic metabolites; and (3) lists of 10 oxy-PAHs and 10 nitro-PAHs are proposed for practical use in the future. A discussion in the scientific community about these lists is invited. Although the state of knowledge has improved dramatically since the introduction of the 16 EPA PAHs in the 1970s, this summary also shows that more research is needed about the toxicity, occurrence in the environment and chemical analysis, particularly of alkylated PAHs, higher molecular weight PAHs and substituted PACs such as amino-PAHs, cyano-PAHs, etc.. We also suggest that a long overdue discussion of an update of regulatory environmental PAH analysis is initiated.     

Indices of PAH Origin—A Case Study of the Gulf of Gdańsk (SE Baltic) Sediments

The aim of this work is to present a way of developing indices for assessing the dominant origin of polycyclic aromatic hydrocarbons (PAHs) on the basis of a case study in the Gulf of Gdańsk (SE Baltic). The indices were based on selected concentration ratios of both parent and alkylated PAHs found in reference matrices that are potential anthropogenic sources of PAH pollution for this area, i.e., airborne particulate matter (PM10) from the Gdańsk conurbation, soot derived from wood and diesel oil combustion, and a variety of petrogenic products. Verification of the suitability of the PAH ratios for source apportionment showed that the following indices are potentially the most useful for distinguishing PAHs of pyrogenic and petrogenic origin: [Σ3-+Σ4-ring-PAHs]/[Σ5-+Σ6-ring-PAHs], ΣmMP/Phen, 4,5-MP/ΣmMP, 1,7-dMP/[1,7-+2,6-dMP]. It was found that PAHs deposited in recent sediments in the Gulf of Gdańsk originate mainly from pyrogenic sources, while perylene is also derived from diagenetic processes.     

Heat treatment of vegetable oils III. GC-MS characterization of cyclic fatty acid monomers in heated sunflower and linseed oils after total hydrogenation

Fractions of cyclic fatty acid monomers (CFAM) were isolated from linseed oil heated at 275°C for 12 hr under nitrogen, at 240°C for 10 hr under nitrogen and at 240°C for 10 hr under air. Cyclic fatty acid monomers fractions were also isolated from a sunflower oil heated at 275°C for 12 hr under nitrogen and at 200°C for 48 hr in a commercial fryer. The CFAM fractions were hydrogenated and their composition studied by gas liquid chromatography coupled with mass spectrometry (GC-MS). The CFAM in the fraction isolated from heated linseed oil samples were a mixture (1:1) ofcis andtrans cyclopentyl and cyclohexyl isomers, while the CFAM in the fractions isolated from heated sunflower oils were mostly cyclopentyl isomers. The major cyclopentyl isomers weretrans andcis methyl 7-(2′-hexylcyclopentyl) -heptanoate, methyl 9-(2′-butyl-cyclopentyl)-nonanoate and methyl 10-(2′-propylcyclo-pentyl)-decanoate. The major cyclohexyl isomers were thetrans andcis methyl 9-(2′-propylcyclohexyl)-nonanoate which represented about 50% of the CFAM isomers isolated from heated linseed oil samples. For part II in this series see Ref. 1.     

Three Centuries of Polycyclic Aromatic Hydrocarbons and Teriterpane Records In Tebrau Strait,Malaysia; Recent Pollution Concern in a Pristine Marine Environment

In the last century, application of fossil fuel as the primary source of energy caused environmental pollution in many countries including Malaysia. Polycyclic Aromatic Hydrocarbons (PAHs) are an important class of petroleum contamination. Two sediment cores were collected from the Tebrau Strait at the southern part of Peninsular Malaysia near the border line to Singapore, where entering into the South China Sea. The samples were sliced in certain intervals, extracted with Dichloromethane in Soxhlet apparatus, cleaned and fractionated in 2-steps column chromatography, and analyzed in Gas Chromatography – Mass Spectrometry. The results showed that PAHs input were started soon after World War II and exponentially increased from 1980 onward by 310 ng/g d. w., in comparison it was negligible and probably nature derived during 18^th and 19^th century. The application of compound-specific ratios and pentacyclic teriterpanes suggested the vicinity of sources that atmospherically transported to the sampling locations. They were originated from combusted oil of Southeast Asian and the Middle East, polluting urban sediment and street dusts prior to final deposition. Biomass burning appeared historically as a predominant minor background pollution of both cores. Remarkably, crankcase oil was not traced in this study while it was reported as a predominant source in Malaysia. This study suggested ocean-going ships and Singapore International Airport as the main sources of petroleum pollution in recent decades since there was insignificant rural development surrounding the studied area.     

Priority Polycyclic Aromatic Hydrocarbons (PAHs): Distribution,Possible Sources and Toxicity Equivalency in Urban Drains

Wastewater from urban areas constitutes one of the major sources of pollutants contributed to aquatic ecosystem. This study was carried out to elucidate the occurrence and possible source of US Environmental Protection Agency identified 16 priority polycyclic aromatic hydrocarbons (PAHs) in water and sediments from the urban wastewater drains in Delhi, India. A total 60 samples (water and sediment) collected during year 2011–2012, and analyzed the following USEPA methods. Water and sediment samples were extracted using liquid-liquid and ultrasonication techniques, respectively. Glass column chromatography with activated silica was used for sample extracts clean-up, followed by quantification on HPLC equipped with diode array detector at 254 nm wavelength using mixture of acetonitrule and water as mobile phase. Concentrations of total 16 PAHs (∑16PAHs) in all drain water samples ranged from 0.29–35.22 μg/L (mean ± SD, 10.83 ± 10.66 μg/L), predominated by two- and three -ring PAHs. The ∑16PAHs concentrations in all collected sediments ranged between 220–19321 μg/kg (mean±SD, 5574 ± 6820 μg/kg) dry weights. High molecular weight PAHs (≥4-ring PAHs) were dominant in sediment samples. Benzo(a)pyrene equivalent (BaPeq), a relative carcinogenic potential to the corresponding PAHs to BaP was estimated and presented. A selected number of concentration ratios of specific PAHs compounds were calculated and used to diagnose the possible sources of PAHs contamination. The diagnostic ratios reflected pyrogenic input from gasoline or diesel powered vehicular emissions as the major source of PAHs. The levels of PAHs observed in water and sediments were compared with similar studies undertaken in other regions of the world.     

Source Allocation of Aliphatic and Polycyclic Aromatic Hydrocarbons in Particulate-Phase (PM10) in the City of Valdivia,Chile

The concentration and signature of n-alkanes (n-C₁₀ to n-C₃₃) and 18 PAHs were determined in air filters across a year period (2010) in an urban area of the city of Valdivia, Chile. Filter samples were extracted using sohxlet apparatus and analyzed by GC-MS techniques. Concentrations of total hydrocarbons ranged from 45–352 ng.m^?3 and total PAHs ranged from 2.93–78.01 ng.m^?3. Concentrations of hydrocarbons during the summer were high (288–352 ng.m^-3) and reduced when the autumn began (45–79 ng.m^?3) to then increase almost linearly to the next summer. The drop in concentration was attributed in part to the significant reduction of traffic when summer ends as tourists leave the city (about 9–15% of the total cars circulating). Results from the chemometric technique of Polytopic Vector Analysis (PVA) indicated three main sources for the alkanes: biogenic (terrestrial plants), signatures of oil combustion, and an unconfirmed source which is thought to come from non specific organic matter degradation. Total PAHs correlated well with total particulate matter with a R² = 0.94. Levels of PAHs in the atmosphere were higher during the winter (6.85–78.01 ng.m^?3) period than the rest of the year (2.93–36.30 ng.m^?3). PVA results indicate three key sources of PAHs and two of those sources derived from oil combustion and biomass burning.     

Modifying carbonization properties of pitches. 3. Carbonization of modified quinoline-insoluble matter from pitches

The carbonization of solubilized matter obtained from the hydrogenated and reductively alkylated quinoline-insolubles of pitches was studied to clarify the different carbonization properties shown by these materials. Dehydrogenation of hydrogenated QI started at 200 °C but continued until 400 °C, passing through a fused phase to give graphitizable carbon. In contrast, alkylated QI gave non-graphitizable carbon because it readily reverted to QI by dealkylation below 300 °C, before fusion. QI alkylated with butyl or benzyl groups was found to be nearly 80% soluble in benzene.     

Evolution of thermograph parameters during the oxidation of extra virgin olive oil

The modulated differential scanning calorimetry (M‐DSC) was used as a rapid and effective method to characterize the olive oil at different levels of oxidation. Thermograph parameters have been related to oxidative degradation of the triglycerides. In this study, their relation to the characteristic off‐flavor compounds, correlated to the oxidative degradation of the oil, was also investigated. Extra virgin olive oil samples were subjected to the following oxidation treatments: a) purged with air using glass washing bottles at two flow rate values, b) heated in a conventional oven at two area/oil mass ratios, and c) heated in a microwave oven also at two area/oil mass ratios. Samples were withdrawn and analyzed at predetermined intervals. Flavor and off‐flavor compounds were isolated using a dynamic thermal stripping apparatus and transferred into a gas chromatograph by using a thermal desorption unit. All oil samples were analyzed by M‐DSC during cooling from 25 °C to ?60 °C at 7 °C/min, and heating back to 40 °C at 10 °C/min. High correlation values were obtained between various M‐DSC thermograph parameters and certain volatile compounds. Results showed that M‐DSC could be used as a simple method to indicate compositional changes in olive oil during oxidation.     

Multivariate determination of cloud point in palm oil using partial least squares and principal component regression based on FTIR spectroscopy

A rapid FTIR spectroscopic method was developed for quantitative determination of the cloud point (CP) in palm oil samples. Calibration samples were prepared by blending randomized amounts of palm olein and palm stearin to produce a wide range of CP values ranging between 8.3 and 47.9°C. Both partial least squares (PLS) and principal component regression (PCR) calibration models for predicting CP were developed by using the FTIR spectral regions from 3000 to 2800 and 1800 to 1600 cm⁻¹. The prediction capabilities of these calibration models were evaluated by comparing their standard errors of prediction (SEP) in an independent prediction set consisting of 14 palm oil samples. The optimal model based on PLS in the spectral range 1800-1600 cm⁻¹ produced lower SEP values (2.03°C) than those found with the PCR (2.31°C) method. FTIR in conjunction with PLS and PCR models was found to be a useful analytical tool for simple and rapid quantitative determination of CP in palm oil.     

Effects of various roasting conditions on acrylamide,acrolein, and polycyclic aromatic hydrocarbons content in cocoa bean and the derived chocolates

The effect of roasting parameters such as the temperature (135 and 150°C) and relative humidity of air (RH of 0.3 and 5.0%) on acrylamide, acrolein, and polycyclic aromatic hydrocarbon (PAH) levels in whole and crushed cocoa beans and chocolates derived from these beans was studied. Acrylamide was identified in all tested samples of roasted cocoa beans, irrespective of process conditions. Its contents in chocolates produced from these beans were similar. The highest acrylamide concentration was found in whole cocoa beans roasted at 135°C and RH of 5.0%. Small amounts of acrolein were present only in the roasted whole cocoa beans while neither the roasted crushed cocoa beans nor chocolates contained this aldehyde. Roasting conditions significantly affected the profile and content of PAHs in whole and crushed cocoa beans and the richest in PAHs were crushed cocoa beans roasted at 150°C and RH of 5.0%. The chocolates obtained in this study contained significantly higher concentrations of PAHs than the roasted cocoa beans used for their production. The results of the study demonstrate that optimization of roasting conditions may reduce levels of all these harmful substances in cocoa beans.