THE FATE AND BEHAVIOR OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) THROUGH FEEDING AND EXCRETION OF ANNELIDS

The concentration of polycyclic aromatic hydrocarbons (PAHs) in sediment and excrements of annelids was measured by gas chromatography-mass spectrometry (GC/MS) and the movement of PAHs in the tidal flat was investigated. The PAH concentrations ranged 4.4–80.4 and 61.2–286.9 μg/kg-dry for the excrement of Arenicola basiliensis and of Marphysa sanguinea, respectively; the former contained about 10 times as much PAHs as the sediment and the latter about 100 times. The difference in the PAH concentration between the two organisms was attributed to their feeding behavior; M. sanguinea intakes much more detritus containing PAHs than A. basiliensis. Moreover, after the excrement of M. sanguinea had stood on the sediment for 2 hours, the PAH concentrations decreased to half. The reduction of the PAHs may arise from chemical changes owing to microorganisms and/or enzymes in the excrement of M. sanguinea.     

DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHs) IN SEDIMENTS AND BENTHOS COLLECTED ON THE COAST OF CHIBA

Eight polycyclic aromatic hydrocarbons (PAHs) including benzo[a]pyrene were analyzed in sediment and benthos collected on the coast of Chiba Prefecture in Japan by gas chromatography-mass spectrometry (GC/MS). The total concentration of the PAHs ranged from 8 to 18 μ g/kg-dry in the sediments and from 36 to 59 μ g/kg-wet in the benthos, Mactra quadrangularis, Scoletoma nipponica, and Arenicola basiliensis. The PAH composition in the sediments and the benthos was similar at four sampling points and dominated by phenanthrene (Phe), fluoranthene (Flu), and pyrene (Pyr). The ratios of abundance of Flu to that of Pyr, Flu/Pyr, and of Phe/anthracene suggest that the PAHs in the benthos are derived from the combustion of fossil fuels. The ratio, R, of the PAH concentration in the benthos to that in the sediment is 2.0 for Scoletoma nipponica and 1.8 for Arenicola basiliensis in average, indicating that the bioaccumulation is not significant in the benthos. However, the R value for perylene in Scoletoma nipponica was 3.7 times as large as the average.     

SEPARATION OF AROMATIC AND ALIPHATIC HYDROCARBONS WITH IONIC LIQUIDS

Naphtha cracker feeds may contain 10-25 wt% aromatic compounds. Removal of these aromatic compounds from the feed to the cracker would offer several advantages: higher capacity, higher thermal efficiency, and less coke formation. In this work, we investigated the separation of toluene from heptane by extraction with ionic liquids.

Several ionic liquids are suitable for extraction of toluene from toluene/heptane mixtures. The selectivities for the aromatic/aliphatic hydrocarbon separation with all ionic liquids tested increase with decreasing aromatic content in the feed. The toluene/heptane selectivities at 10% toluene in the feed at T = 40°C and 75°C with several ionic liquids ([emim]HSO₄, [mmim] methylsulfate, [emim] ethylsulfate, [bmim]BF₄, [emim] tosylate, [mebupy]BF₄, and [mebupy] methylsulfate) are a factor of 1.5-2.5 higher than those obtained with sulfolane, which is a conventional solvent for the extraction of aromatic hydrocarbons from a mixed aromatic/aliphatic hydrocarbon stream. The three most suitable ionic liquids from the ionic liquids tested for the separation of aromatic and aliphatic hydrocarbons are [mebupy]BF₄, [mebupy]CH₃SO₄, and [bmim]BF₄ and at 75°C also [emim] tosylate. The ionic liquid [mebupy]BF₄ is selected for further testing in our extraction pilot plant.

Because ionic liquids have a negligible vapor pressure, evaporating the extracted hydrocarbons from the ionic liquid phase could achieve the recovery of the ionic liquid. A conceptual process scheme for the extraction has been set up. Preliminary calculations show that both the investment costs and the energy costs will be considerably lower with ionic liquids than with sulfolane as the solvent.     

HETEROGENEOUS REACTIONS OF OH RADICALS WITH PARTICULATE-PYRENE AND 1-NITROPYRENE OF ATMOSPHERIC INTEREST

The heterogeneous reactivity of OH radicals with pyrene and 1-nitropyrene adsorbed on model particles has been investigated using a discharge flow reactor, in the presence of a large excess of NO ₂ . Graphite was chosen as a simple model of carbonaceous particles, whereas silica was chosen as a representative surrogate of mineral atmospheric aerosol. The reaction kinetics was investigated by measuring the remaining pyrene and 1-nitropyrene adsorbed on particles after pressurized fluid extraction and gas chromatography/mass spectrometry analysis. Pseudo-first order rate constants were obtained from the fit of the experimental decay of particulate polycyclic compound concentrations versus reaction time. Rate constants were measured at room temperature for reactions of OH radicals with, respectively, pyrene, 1-nitropyrene, both adsorbed on silica, and 1-nitropyrene adsorbed on graphite, in the presence of NO ₂ .     

IN VITRO INTESTINAL TRANSFER AND METABOLISM OF POLYCYCLIC AROMATIC HYDROCARBONS

Though polycyclic aromatic hydrocarbon (PAH) transfer through intestinal epithelium seems principally governed by transcellular diffusion, other mechanisms may interfere. Several studies suggest a PAH metabolism via CYP450, particularly in liver, but only few data are available regarding intestinal barrier. This in vitro work aimed at studying PAH metabolism and its consequences on the transfer in the intestinal epithelium according to molecule physicochemical properties. It used ¹⁴C-labeled benzo[a]pyrene, pyrene, and phenanthrene. Medium analysis proved a metabolism in intestinal cells for each PAH. Parallel metabolism appeared to play a positive role in the intestinal transfer of PAHs under different forms: ¹⁴C from benzo[a]pyrene, pyrene, and phenanthrene were respectively transferred 26, 4, and 2 times less when cells were incubated with CYP450 inhibitors. Generally speaking, the faster and the higher a PAH crosses intestinal barrier, the less metabolized it will be.     

POLYCYCLIC AROMATIC HYDROCARBONS IN PRODUCTS OF A BEET SUGAR FACTORY IN VOJVODINA: LEVELS AND INTAKES

The levels of 16 EPA polycyclic aromatic hydrocarbons (PAHs) were investigated in samples of sugar beets and their products representative for a beet sugar factory located in the central part of Vojvodina, the main agricultural region in Serbia. The sum of the detected PAHs ranged from 51 pg g ^?1 ww for molasses to 391 pg g ^?1 ww for dried sugar beet pulp. The concentration of benzo(a)pyrene (BaP) for all sample types was about or less than 100 pg g ^?1 ww, which is far less than the existing Serbian and EU tolerances set for some foodstuffs. The Serbian intake of BaP via total sugar consumption that ranged from 70–85 g per capita day ^?1 , was assessed to be from 0.029 to 0.035 ng kg ^?1 b.w. day ^?1 . Furthermore, the toxic equivalency factor (TEF) approach was used to estimate the carcinogenicity of PAH mixture found in analyzed samples.     

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.     

ADSORPTION AND RECOVERY OF NITRATED POLYCYCLIC AROMATIC HYDROCARBONS ON HYBRID SURFACTANT EXPANDED ZIRCONIUM-PHOSPHATE

This paper focuses on the removal of nitro substituted polycyclic aromatic hydrocarbon compounds (NPAHs) from water using low cost synthesized zirconium phosphate mesoporous materials. These materials are lamellar type incorporating n-alkyl-(n = 12 and n = 16) trimethylamonium bromide molecules with different concentrations. For comparison of their performance as adsorbents and in the recovery of NPAH, their results were compared with commercial ENVI-18 extraction tubes and three dimensional type material incorporating hexadecyl-trimethyl ammonium bromide. The adsorption yield for the new materials were almost 100% and the recovery factors with dichloromethane as eluent was nearly 100%. Best results were obtained by preparing lamellar zirconium and titanium phosphates in the presence of n-dodecyl-trimethylammonium. This material has several environmental advantages because zirconium salts are non-toxic and their synthesis costs is relatively small.     

SAMPLING AND ANALYSIS OF POLYCYCLIC AROMATIC HYDROCARBONS IN URBAN AND RURAL ATMOSPHERES: SPATIAL AND GEOGRAPHICAL VARIATIONS OF CONCENTRATIONS

Atmospheric sampling (gas and particles) of PAHs (naphthalene, acenaphthene, fluorene, anthracene, phenanthrene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[j]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, benzo[ghi]perylene, dibenz[a,h]anthracene, indeno[1,2,3-cd]pyrene, coronene) on XAD-2 resin (20 g) and glass fiber filters respectively, were performed in 2002 by using Digitel DA80 high-volume samplers equipped with a PM10 head. Samplings were performed in Strasbourg (east of France) and its vicinity (Schiltigheim and Erstein). Sites were chosen to be representative of urban (Strasbourg), suburban (Schiltigheim), and rural (Erstein) conditions. Field campaigns were undertaken simultaneously in urban, and suburban, urban and rural sites during spring and autumn during 4 h at a flow rate of 60 m³/h^?1 which gives a total of 240 m³ · h^?1 of air per sample. The period of sampling varied between 06:00 to 10:00, 11:00 to 15:00, 17:00 to 21:00 in order to evaluate a variation of concentration during automobile traffic between urban, suburban, and rural areas. Gas and particle samples were separately Soxhlet extracted for 12 h with a mixture of CH₂Cl₂/n-hexane (50:50 v/v), concentrated to about 1 mL with a rotary evaporator and finally dried under nitrogen. Dry extracts were dissolved in 1 mL of CH₃CN before analysis. Before use, traps were Soxhlet cleaned for 24 h with the same mixture as used for the extraction. Analysis of each extract was performed by reverse phase HPLC, and fluorescence detection and quantification was done with respect to triphenylene used as internal standard. Results shows that automobile traffic seems to be the main source of PAHs in urban areas whatever the period (autumn and spring) while in autumn other sources, especially coming from combustion, influence the atmospheric contamination by PAHs.     

TOXICOKINETICS OF POLYCYCLIC AROMATIC HYDROCARBONS FROM CONTAMINATED SEDIMENT BY THE AMPHIBIAN LARVAE (PLEURODELES WALTL)

The molecular phototransformation mechanism of nitroarenes, genotoxic and ubiquitous pollutants in the atmosphere, is still under debate. With increasing exposure to radiation 1,6- and 1,8-dinitropyrene (DNP) in acetonitrile showed a decrease in their characteristic absorption bands (396 and 411 nm, respectively) in the presence of O ₂ , N ₂ and H ₂ O, and an increase in the 220–390 nm region and above 450 nm, indicating their photodegradation and transformation. The resulting photoproducts were highly fluorescent, presenting a broad emission band around 520–540 nm. Oxygen reactive species did not seem to be produced in the principal photodegradation pathways, since photodegradation rates were similar to those in anaerobic samples. In the presence of O ₂ or N ₂ 1,6-DNP photodegraded 4 times faster than 1,8-DNP, while in the presence of water is 1.5 times faster. Two chromatographic fractions were separated, and identified as pyrenediones using authentic samples and reported spectral data for hydroxy-nitropyrenes. Other chromatographic fractions are still to be identified. The properties of the identified products suggested that these were formed through a nitro-nitrite rearrangement.     

LEAVES OF NERIUM OLEANDER L. AS BIOACCUMULATORS OF POLYCYCLIC AROMATIC HYDROCARBONS (PAH) IN THE AIR OF PALERMO (ITALY): EXTRACTION AND GC-MS ANALYSIS,DISTRIBUTION AND SOURCES

Polycyclic Aromatic Hydrocarbons (PAH) were determined in the leaves of Nerium oleander L. an evergreen plant that occurs widely in both urban and rural areas, to monitor the degree of pollution in the urban area of Palermo (Italy) compared to remote areas. Twenty sites (urban roadside, urban, urban park, suburban and rural) in and around Palermo city were investigated.

The purpose of this research was to investigate concentration levels and distribution patterns and relate them to possible sources. Analysis of 19 PAH was performed by gas chromatography/mass spectrometry (GCMS) using selected ion monitoring (SIM). The total amount of PAH ranged from 10 to 166 μg/Kg d.w.

Each source gives rise to a characteristic PAH pattern, and it is therefore possible to get access to the processes that generate the compounds. To this aim, the recommended as priority pollutants by the Environmental Protection Agency (EPA), perylene and three additional alkylated compounds were analyzed.

Positive correlations were found between total PAH content of the leaves with CO, benzene and particulate levels measured in air of Palermo.     

SIMULTANEOUS GC/MS ANALYSIS OF POLYCYCLIC AROMATIC HYDROCARBONS AND THEIR NITRATED DERIVATIVES IN ATMOSPHERIC PARTICULATE MATTER FROM WORKPLACES

Abstract

PAH are routinely analyzed using HPLC/FD. This technique is unsuitable for analyzing NPAH. This study aims at developing a reliable method, using GC/MS, and applying this technique to actual samples from small volumes of atmospheric particulate matter from workplaces. Mixtures of PAH and NPAH were separated by GC/MS and detected by electronic impact (EI) or negative ion chemical ionization (NICI). Analyses on twelve actual samples were thus carried out by sampling a small volume of atmosphere (≈0.5 m ³ ) from five different industrial workplaces. Samples displayed wide differences from one industrial workplace to another, and this can be explained by the specific methods applied. The PAH and NPAH concentrations also varied with time in the same industrial workplace. NPAH concentrations were not correlated with PAH concentrations, underscoring the complex chemical mechanisms involved in NPAH formation. PAH and NPAH formation appeared to be dependent on both industrial activities and uncontrolled physicochemical conditions.     

SEMIPERMEABLE MEMBRANE DEVICE-AVAILABILITY OF POLYCYCLIC AROMATIC HYDROCARBONS IN RIVER WATERS AND WASTEWATER TREATMENT PLANT EFFLUENTS

River waters and wastewater treatment plant effluents contain hydrophobic organic compounds (HOCs) such as polycyclic aromatic hydrocarbons (PAHs) which are persistent, bioaccumulative, and dangerous for the environment. The biological risk assessment of HOCs requires the estimation of their bioavailable fraction in addition to the total contamination of the media. The bioavailability of HOCs depends on the characteristics of the aquatic environments. In particular, the presence of organic matter (OM) usually reduces the bioavailability of HOCs by trapping them and preventing them from crossing biological membranes. The semipermeable membrane device (SPMD) technique is used to evaluate bioavailable fractions of HOCs. We tested the influence of aquatic and more particularly OM characteristics on the SPMD-availability of PAHs, in several river waters (up and downstream a large town) and in wastewater treatment plant effluents. Thirteen priority PAHs were analyzed in total water and in SPMDs. Aquatic environments were characterized for their pH, ionic strength, temperature, chlorophyll A, and suspended solids contents. Total and dissolved OMs were characterized for aromaticity, biodegradability, molecular weight, and hydrophobicity. The total PAH contamination increased downstream the river; wastewater effluents were proven to be a source of SPMD-available PAHs. We attempted to establish relationships between the characteristics of organic matter and the SPMD-availability in order to initiate an aquatic environment typology: The SPMD-availability was negatively related to dissolved OM molecular weight and aromaticity, and positively related to biodegradability.     

DETERMINATION OF ATMOSPHERIC NITRO-POLYCYCLIC AROMATIC HYDROCARBONS AND THEIR PRECURSORS AT A HEAVY TRAFFIC ROADSIDE AND AT A RESIDENTIAL AREA IN OSAKA,JAPAN

Concentrations of nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) and polycyclic aromatic hydrocarbons (PAHs) in airborne particles collected at two sites, a residential area and a roadside with high traffic density in Osaka, Japan, in summer and winter were quantified. Five nitro-PAHs, 1-nitropyrene (1-NP), 2-nitropyrene (2-NP), 2-nitrofluoranthene (2-NF), 3-nitrofluoranthene (3-NF), and 2-nitrotriphenylene (2-NTP) and five PAHs, pyrene (Py), fluoranthene (Fl), triphenylene (Tp), benzo[k]fluoranthene (B(k)F), and benzo[a]pyrene (B(a)P) were determined by high-performance liquid chromatography with chemiluminescence and fluorescence detection. At both sites, the mean concentration of 1-NP was higher in winter than in summer. On the contrary, the mean concentrations of 2-NF and 2-NP were higher in summer than in winter. Observed 2-NF/2-NP ratio in the range from 0.40 to 16 suggests that 2-NF and 2-NP were dominantly formed via OH radical initiated reaction in the atmosphere. Nitro-PAH and PAH concentrations were generally higher at a roadside area than at a residential area due to extremely higher concentration of particles at a roadside area. 1-NP/B(k)F ratio was higher at a roadside area than at a residential area, while 2-NF/B(k)F, 2-NP/B(k)F, and 2-NTP/B(k)F ratios were higher at a residential area than at a roadside area. The diurnal changes of 2-NF/B(k)F, 2-NP/B(k)F, and 2-NTP/B(k)F ratios were slightly different from those of 1-NP/B(k)F and 3-NF/B(k)F ratios. Thus, the differences in the patterns of nitro-PAHs/B(k)F ratios may be due to the disparity in formation pathways of each nitro-PAH.     

GAS-PARTICLE PARTITIONING OF POLYCYCLIC AROMATIC HYDROCARBONS DURING THE SPRING AND SUMMER IN A SUBURBAN SITE NEAR MAJOR TRAFFIC ARTERIES

Concentrations of atmospheric polycyclic aromatic hydrocarbons were measured in a suburban site near major traffic arteries during the period April-August 2006. Total suspended particulate during the sampling period was 65.3 ± 33.9 μ g m^?3. Total PAH concentrations were 63.5 ± 20.1 ng m^?3 in the gaseous phase and 1.4 ± 0.3 ng m^?3 in the particulate phase. Observed concentrations were comparable with previously measured values reported in the literature for urban and suburban sites with a high anthropic influence. PAH concentration diagnostic ratios indicate that, during the spring and summer seasons, vehicular emission was the main source of atmospheric PAHs.

Gas/particle partitioning coefficients K _P were well correlated with both the sub-cooled liquid vapor pressures p _L ⁰ and the octanol-air partition coefficients K _OA . Measured K _P values were in a good agreement with K _P values predicted by applying a literature model, which takes into account both adsorption onto black carbon and absorption into the organic matter.     

EFFECTS OF FLOW RATE AND TEMPERATURE ON THE DISSOLUTION OF POLYCYCLIC AROMATIC HYDROCARBONS TRANSFERRING FROM A NONAQUEOUS PHASE LIQUID TO NONIONIC SURFACTANT SOLUTIONS

The effects of flow rate and temperature on the dissolution of two polycyclic aromatic hydrocarbon (PAH) compounds, naphthalene and phenanthrene, transferring from a synthesized nonaqueous phase liquid (NAPL) comprised of hexadecane and the 2 PAHs into different nonionic surfactant solutions were investigated using a reactor with a spinning cell. The variation of the flow rate was possible by changing the angular velocity of the spinning cell. The flow rate generally increased the values of the mass transfer coefficients and the rates of mass transferred for both aromatics in the absence and presence of a surfactant in the aqueous phase. In comparison to the pure aqueous solution the results suggest that the addition of a surfactant at all doses investigated enhanced the rates of mass transfer for both PAHs. As the temperature increased the rates of mass transfer for both PAHs in the solutions of surfactants increased. The increase in the temperature has a much greater effect on the rates of mass transfer for both PAHs in solutions of the surfactant Triton X-100 than in Brij 35. In solutions of the surfactant Triton X-100 a decrease in the mass transfer coefficient for both PAHs with surfactant concentration was observed for the temperatures investigated.     

URINARY 3-HYDROXYBENZO[A]PYRENE AS A BIOMARKER OF EXPOSURE TO POLYCYCLIC AROMATIC HYDROCARBONS: AN APPROACH FOR DETERMINING A BIOLOGICAL LIMIT VALUE

Atmospheric and biological monitoring was carried out on 38 people exposed to polycyclic aromatic hydrocarbons in different workplaces. The relationship between the atmospheric BaP and the 3-OHBaP urinary concentration peaks was determined. To avoid misinterpretation due to dermal exposure, only people with mainly respiratory exposure were chosen. The selection was carried out from observation of working conditions and from urinary data. For the limit value determination, BaP concentrations higher than 5,000 ng/m³ were discarded and the 3-OHBaP values were adjusted to a 8 h exposure time. A close relationship was observed between the two variables: n = 17, r = 0.89, p < .0001 (C 3-OHBaP = 0.001835*C BaP + 0.1729). To estimate the 3-OHBaP limit concentration, the French recommended value of 150 ng/m³ for atmospheric BaP was used. The corresponding 3-OHBaP was 0.45 nmol/mol creatinine. This value could be used as a sound basic element for determining a biological exposure index.     

IDENTIFICATION OF THE C30H16 POLYCYCLIC AROMATIC HYDROCARBON BENZO[cd]NAPHTHO[1,2,3-lm]PERYLENE AS A PRODUCT OF THE SUPERCRITICAL PYROLYSIS OF A SYNTHETIC JET FUEL

Using high-pressure liquid chromatography (HPLC) with ultraviolet-visible (UV) diode-array and mass spectrometric detection, we have analyzed the products of a Fischer-Tropsch synthetic jet fuel pyrolyzed, under supercritical conditions, at 710°C and 42 atm. An eight-ring polycyclic aromatic hydrocarbon, benzo[cd]naphtho[1,2,3-lm]perylene, has been unequivocally identified among the product components by its characteristic ultraviolet-visible absorbance spectrum. First, the unknown product component's HPLC elution behavior and UV absorbance characteristics indicated that it was a planar benzologue of dibenzo[cd,lm]perylene, having a high length-to-breadth ratio. Next, the mass spectrum established the isomer family of the unknown compound as C₃₀H₁₆. The UV absorption spectrum was then progressively analyzed with different solvents to achieve the final identification of benzo[cd]naphtho[1,2,3-lm]perylene. Benzo[cd]naphtho[1,2,3-lm]perylene has never before been reported as a product in any combustion or pyrolysis study.     

A COMPARISON OF HPLC WITH FLUORESCENCE DETECTION AND FIXED WAVELENGTH FLUORESCENCE METHODS FOR THE DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBON METABOLITES IN FISH BILE

Fish exposed to polycyclic aromatic hydrocarbons (PAHs) accumulate only a small amount of PAH in their tissues. Hydrophobic PAHs are readily transformed into hydrophilic metabolites and excreted in bile. Bile samples of five fish species were collected from the Baltic Sea and analyzed using two methods: high-performance liquid chromatography (HPLC) with fluorescence detection and a fixed wavelength fluorescence method. With the HPLC method PAH compounds were quantitated after hydrolysis, and with the fluorescence method without enzyme-assisted hydrolysis. In HPLC analysis the major metabolite in all fish species, 1-hydroxypyrene, was the only metabolite detected in perch and salmon samples. 1-Hydroxyphenanthrene was detected in a few flounder and in most eelpouts. The correlation between the two methods for pyrene-type metabolites was good (r² = 0.773).