Distribution,sources, and ecological risk assessment of SVOCs in surface sediments from Guan River Estuary,China

The contamination of semi-volatile organic compounds (SVOCs) in the surface sediments of the Guan River Estuary, China was fully investigated. Total concentrations of 56 species of SVOCs ranged from 132 to 274 ng/g with an average of 186 ng/g (dry weight). Polycyclic aromatic hydrocarbon (PAH) concentrations were positively correlated with clay content and negatively correlated with sediment grain size. Source identification indicated that PAHs originated mainly from pyrolytic sources. However, intense ship traffic in the estuary may provide sources of petrogenic PAHs. Organochlorine pesticides (OCPs) mainly originated from direct input of dichlorodiphenyltrichloroethanes (DDTs) during some industrial processes. The SVOC concentrations were also compared with International Sediments Quality Guidelines and Sediments Quality Criteria, and the results indicated that negative biological impacts may originate from high concentrations of FLO, p,p′-DDE, and total DDTs.     

Impact of urbanization on the concentrations and distribution of organic contaminants in boreal lake sediments

The main goal of this study was to evaluate the impacts of a middle-sized Finnish urban area on the quality of sediments in an adjacent boreal lake. We investigated the sources and distribution of organic pollutants (polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs)) in the sediments from urban stormwater traps and from Lake Vesijärvi. Grab surface sediment samples were taken from Lake Vesijärvi at various distances (25–2,000 m) from four major stormwater drainage outlets and at 15 urban stormwater traps in areas with different degrees of urbanization. These samples were analysed for 16 PAHs and 28 PCBs with gas chromatography–mass spectrometry. The concentrations of pollutants in the lake sediments were elevated in the vicinity of the urban shore (∑PAH 3–16, ∑PCB up to 0.02–0.3 mg/kg dw) and decreased as a function of distance (∑PAH 0.1–2.5, ∑PCB 0.01–0.3 mg/kg dw at a distance of more than 500 m from the shore), whereas contamination levels in suburban areas were notably lower (∑PAH 0.1–3, ∑PCB?<?LOQ–0.03 mg/kg dw; did not decline with distance). Possible sources and pathways of contamination were also investigated. The majority of stormwater trap sediments contained predominantly asphalt-derived PAHs due to pulverized pavement. PAHs in lake sediments were of pyrogenic origin, including the combustion of gasoline, diesel and coal. Suggested pathways of lake contamination are urban runoff discharge, boat traffic and atmospheric deposition.     

Aliphatic and polycyclic aromatic hydrocarbons in the surface sediments of the Mediterranean: assessment and source recognition of petroleum hydrocarbons

Coastal marine sediment samples were collected from ten sampling stations along the Egyptian Mediterranean coast in April 2010. All sediment samples were analyzed for aliphatic (C7 to C34) and polycyclic aromatic hydrocarbons (PAHs) as well as total organic carbon (TOC) contents and grain size analysis. Total aliphatic hydrocarbons ranged from 1621.82 to 9069.99 ng/g (dry weight), while aromatic hydrocarbons (16 PAHs) varied between 208.69 and 1020.02 ng/g with an average of 530.68?±?225.86 ng/g?dwt. Good correlations observed between certain PAH concentrations allowed to identify its origin. The average TOC percent was varied from 0.13 to 1.46 %. Principal component analysis was used to determine the sources of hydrocarbon pollutants in sediments of Mediterranean. Additionally, special PAHs compound ratios suggest the petrogenic origins.     

Polycyclic aromatic hydrocarbons in river sediments from the western and southern catchments of the Bohai Sea, China: toxicity assessment and source identification

The concentration, distribution, and origin of 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) were investigated in river sediments from the western and southern catchments of the Bohai Sea, China. A toxicity assessment of 28 sediment samples collected from 15 main rivers was conducted by utilizing threshold and probable effect concentrations (TEC and PEC, respectively) derived from consensus-based sediment quality guidelines. The concentrations of total PAHs (∑PAH₁₆) ranged from 0.14 to 10,757 μg/kg dry weight (mean?=?1,368.6 μg/kg). The high concentrations of PAHs found in Binhai New Area of Tianjin and Binzhou City are likely the result of rapid population and heavy industry growth, resulting in elevated point and nonpoint source inputs of PAHs. Of the samples collected, samples 1 and 10 (7.1 % of the total) were categorized as toxic since some of the PAH concentrations exceeded the corresponding PECs. Twenty samples were classified as nontoxic, with both the individual PAH and the∑PAH₁₆ concentrations falling below the corresponding TECs. Analyses of selected PAH isomer ratios aided in the identification of PAH origins, allowing for a discrimination between pyrogenic and petrogenic sources. Spatial variability confirmed source heterogeneity within the study area. The most significant PAH-associated contamination was found in the Beitang River and Ji Canal, which are located in Binhai New Area. The magnitude of contamination and the likelihood of an ongoing influx of PAHs support the need for a better understanding of pollution sources and methods for both control and sediment restoration.     

Chemometrics in assessment of seasonal variation of water quality in fresh water systems

The spatial and temporal distribution of polycyclic aromatic hydrocarbons (PAHs) was investigated in Gomti River, a major tributary of the Ganga river (India). A total of 96 samples (water and sediments) were collected from eight different sites over a period of 2 years and analysed for 16 PAHs. The total concentrations of 16 PAHs in water and bed sediments ranged between 0.06 and 84.21 ??g/L (average (n?=?48), 10.33 ± 19.94 ??g/L) and 5.24?C3,722.87 ng/g dw [average (n?=?48): 697.25 ± 1,005.23 ng/g dw], respectively. In water, two- and three-ring PAHs and, in sediments, the three- and four-ring PAHs were the dominant species. The ratios of anthracene (An)/An + phenenthrene and fluoranthene (Fla)/Fla + pyrene were calculated to evaluate the possible sources of PAHs. These ratios reflected a pattern of pyrolytic input as a major source of PAHs in the river. Principal component analysis, further, separated the PAHs sources in the river sediments, suggesting that both the pyrolytic and petrogenic sources are contributing to the PAHs burden. The threat to biota of the river due to PAHs contamination was assessed using effect range low and effect range median values, and the results suggested that sediment at some occasions may pose biological impairment.     

Anthropogenic pollution and variability of manganese in alluvial sediments of the Yellow River,Ningxia, northwest China

Heavy metal pollution of sediments is a global concern and can be a serious problem in heavily industrialized parts of the world. Pollution by manganese is particularly common due to its ubiquitous natural occurrence, ease of mobilization, and extensive association with industry. In Ningxia, China, manganese pollution of Yellow River alluvial sediments was assessed by comparing manganese concentrations in 35 sediment samples with background values derived from similar sediments obtained at sites considered remote from potential sources of contamination. Natural background values of manganese were found to range from 192 to 323 mg/kg for surface sediments, and from 220 to 325 and 283 to 394 mg/kg for subsurface sediments at depths of 45–50 and 95–100 cm, respectively. In the study area, manganese content ranged from 565 to 1,363 mg/kg, indicating anthropogenic pollution extending to a depth of at least 1 m in the study area. All 35 samples were found to exceed the threshold effect concentration (TEC) of 460 mg/kg, below which adverse effects on sediment-dwelling organisms are not expected to occur, and one sample (T12) was found to exceed the probable effect concentration (PEC) of 1,100 mg/kg. PEC defines the threshold above which adverse effects are likely to be observed. Variogram analysis of the surface sediment manganese data revealed adherence to a Gaussian model, and ordinary kriging was used to generate a manganese distribution map. Analysis of the high nugget effect ratio indicates high, small-scale variations that are consistent with potential emissions from an adjacent electrolytic manganese plant.     

Speciation of As(III) and As(V) in water and sediment using reverse-phase ion-pair high-performance liquid chromatography-neutron activation analysis (HPLC-NAA)

Total As content and the As species distribution in water and sediments from the Kwabrafo stream, a major water body draining the Obuasi gold mining community in southwestern Ghana, have been investigated. Total As content was determined by instrumental neutron activation analysis (INAA). Ion-pair reverse phase high-performance liquid chromatography-neutron activation analysis (HPLC-NAA) was used for speciation of As species. Solid phase extraction with phosphate buffer was used to extract soluble As species from lyophilized sediment. The mass balance after phosphate extraction of soluble As species in sediment varied from 89 to 96 %. Compositionally appropriate reference material International Atomic Energy Agency (IAEA)-Lake Sediment (SL)-1 was used to check the validity of INAA method for total As determination. The measured values are in good agreement with the IAEA recommended value and also within the 95 % confidence interval. The accuracy of the measurement in terms of relative deviation from the IAEA recommended value was ±0.83 %. “In-house” prepared As(III) and As(V) standards were used to validate the HPLC-INAA method used for the As species determination. Total As concentration in the water samples ranged from 1.15 to 9.20 mg/L. As(III) species in water varied from 0.13 to 0.7 mg/L, while As(V) species varied from 0.79 to 3.85 mg/L. Total As content in sediment ranged from 2,134 to 3,596 mg/kg dry mass. The levels of As(III) and As(V) species in the sediment ranges from 138 to 506 mg/kg dry mass and 156 to 385 mg/kg dry mass, respectively.     

Polycyclic aromatic hydrocarbons in surface water and bed sediments of the Hungarian upper section of the Danube River

This study was performed to elucidate the distribution, concentration trend and possible source of polycyclic aromatic hydrocarbons (PAHs) in surface water and bed sediments of the Hungarian upper section of the Danube River and the Moson Danube branch. A total of 217 samples (water and sediments) were collected from four different sampling sites in the period of 2001–2010 and analysed for the 16 priority US Environmental Protection Agency PAHs. Concentrations of total 16 PAHs (∑PAHs) in water samples ranged from 25 to 1,208 ng/L, which were predominated by two- and three-ring PAHs. The ∑PAH concentrations in sediments ranged from 8.3 to 1,202.5 ng/g dry weight. Four-ring PAHs including fluoranthene and pyrene were the dominant species in sediment samples. A selected number of concentration ratios of specific PAH compounds were calculated to evaluate the possible sources of PAH contamination. The ratios reflected a pattern of pyrogenic input as a major source of PAHs. The levels of PAHs determined were compared with other sections of the Danube and other regions of the world.     

Distribution of polycyclic aromatic hydrocarbons in marine sediments and their potential toxic effects

The presence of polycyclic aromatic hydrocarbons (PAHs) in samples of marine sediments from Paranagua Bay on the southern coast of Brazil was investigated. Paranagua Bay is the location of a major port, one of the busiest in Brazil. The region has a great potential for tourism and port-related industries and activities. Due to its characteristics as a venue for tourism, two major campaigns were planned: one 3 months before the summer (between December and February) and a second after the vacation season. Total concentration of PAHs in sediments ranged from 26.33 to 406.76 ng/g (in both campaigns). The highest values were found in sediments with higher organic carbon content. We found no substantial differences between the two campaigns, and the values are quite similar. Ternary diagrams show that points P5 and P6 were considered polluted, while others were classified as non-polluted. Molecular ratios indicate that the main sources of PAHs are petrogenic and the burning of fossil fuels. Sediment toxicity was assessed by the presence of PAHs in terms of benzo(a)pyrene (BaP) concentration. The toxicity of PAHs mixtures can be characterized more accurately by developing and establishing toxic equivalency factors (TEFs) for PAHs. Considering TEFs, the BaP_eq concentrations vary between 0.264 and 5.922 ng/g (considering both campaigns). Thus, two points are above the maximum level recommended (3 ng/g) by the Netherlands sediment quality guidelines. In fact, sites P5 and P6 apparently are exposed to a greater number of pollution sources, thus reflecting the higher concentration of PAHs compounds in sediments.     

Spatial and temporal distribution of polycyclic aromatic hydrocarbons (PAHs) in sediments of the Nansi Lake, China

Polycyclic aromatic hydrocarbons (PAHs) were measured in surface sediments and dated core sediments from the Nansi Lake of China to investigate the spatial and temporal distribution characteristics. The concentrations of 16 kinds priority PAH compounds were determined by GC-MS method. And ²¹⁰Pb isotope dating method was used to determine the chronological age of the sediment as well as the deposition rate. The results indicated that the total PAHs concentration ranges in surface and core sediment samples were 160 ~32,600 and 137 ~ 693 ng/g (dry wt.), respectively. The sediment rate and the average mass sedimentation were calculated to be 0.330 cm·year^???1 and 0.237 g·cm^???2·yr^???1 and the sediment time of the collected core sample ranged from 1899 to 2000. The peak of PAH concentrations came at recent years. The source analysis showed PAHs mainly came from the contamination of low temperature pyrogenic processes, such as coal combustion. The PAHs concentrations were lower than ERL and LEL values for most collected samples. However, in several surface sediment samples especially in estuary sites, the PAHs concentrations were not only higher than ERL and LEL values, but also higher than ERM values.     

Multivariate assessment of polycyclic aromatic hydrocarbons in surface sediments of the Beijiang, a tributary of the Pearl River in Southern China

To estimate the severity of polycyclic aromatic hydrocarbon (PAH) contamination in the upper sediment of the Beijiang River, 42 sediment samples were analyzed for the presence of 16 key PAHs using gas chromatography–mass spectrometry. The concentrations of PAH in the sediment ranged from 44 to 8,921 ng g^?1 dry weight. The four- to six-ring PAHs, contributing >50 % to PAHs in 34 of the 42 sites, were the dominant species. Based on a principal component analysis, combined with multivariate linear regression, it became clear that the most important contributors of PAH were fossil fuel combustion (48 %), diesel emissions plus oil spillage (33 %), and coke combustion (19 %). The surface sediments of Beijiang River were grossly contaminated by PAHs mainly derived from combustion.     

Presence, distribution, and origins of polycyclic aromatic hydrocarbons (PAHs) in sediments from Bahía Blanca estuary, Argentina

This paper is the first comprehensive survey of polycyclic aromatic hydrocarbons (PAHs) in coastal sediments in Bahia Blanca, Argentina, and provides useful information on their levels of concentration, composition, and sources of these pollutants. The total concentrations of PAHs ranged from 15 to 10,260 ng g^???1. The highest contents (mean 3,315 ng g^???1) of total PAHs in marine sediments were found in the inner channels of the estuary, while the lower ones (204 ng g^???1) belong to samples collected far away from contamination sources. The global average recorded in this study (1,500 ng g^???1) indicates that the studied area lies within the referenced category of industrialized coastal zones under chronic pollution. The diagenetic PAH contribution was found to be negligible at all sampled locations; however, the calculation of molecular ratios determined an overimposition of pyrolitic PAHs over the petrogenic input. Further, the use of principal components analysis (PCA) clearly separated ring group compounds and enabled the determination of pyrolitic/combustion PAHs dominancy.     

Polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the Bizerte Lagoon,Tunisia: levels,sources, and toxicological significance

To assess the status of polycyclic aromatic hydrocarbon (PAH) contamination in sediments from the Bizerte Lagoon (northern Tunisia), 18 surface sediment samples were collected in March 2011 and analyzed for 14 US Environmental Protection Agency priority PAHs by high-performance liquid chromatography. The total concentrations of the 14 PAHs (ΣPAHs) ranged from 16.9 to 394.1 ng g^?1 dry weight (dw) with a mean concentration of 85.5 ng g^?1 dw. Compared with other lagoons, coasts, and bays in the world, the concentrations of PAHs in surface sediments of the Bizerte Lagoon are low to moderate. The PAHs’ composition pattern was dominated by the presence of four-ring PAHs (45.8 %) followed by five-ring (26.8 %) and three-ring PAHs (12.7 %). The PAH source analysis suggested that the main origin of PAHs in the sediments of the lagoon was mainly from pyrolytic sources. According to the numerical effect-based sediment quality guidelines of the USA, the levels of PAHs in the Bizerte Lagoon should not exert adverse biological effects. The total benzo[a]pyrene toxicity equivalent values calculated for the samples varied from 3.1 to 53.7 ng g^?1 dw with an average of 10.6 ng g^?1 dw.     

Polycyclic aromatic hydrocarbons in water, sediment and soil of the Songhua River Basin, China

The Songhua River is the third largest river in China and the primary source of drinking and irrigation water for northeastern China. The distribution of 16 priority polycyclic aromatic hydrocarbons (PAHs) in water [dissolved water (DW) and suspended particulate matter (SPM)], sediment, and soil in the river basin was investigated, and the associated risk of cancer from these PAHs was also assessed. The total concentration of PAHs ranged from 13.9 to 161 ng L^?1 in DW, 9.21 to 83.1 ng L^?1 in SPM, 20.5 to 632 ng g^?1 dw (dry weight) in sediment, and from 30.1 to 870 ng g^?1 dw in soil. The compositional pattern of PAHs indicated that three-ring PAHs were predominant in DW and SPM samples, while four-ring PAHs dominated in sediment and soil samples. The spatial distribution of PAHs revealed some site-specific sources along the river, with principal component analysis indicating that these were from pyrogenic sources (such as coal and biomass combustion, and vehicle emissions) and coke oven emission distinguished as the main source of PAHs in the Songhua River Basin. Based on the ingestion of PAH-contaminated drinking water from the Songhua River, cancer risk was quantitatively estimated by combining the Incremental Lifetime Cancer Risk assessment model and BaP-equivalent concentration for five age groups of people (adults, teenagers, children, toddlers, and infants). Overall, the results suggest that the estimated integrated lifetime cancer risk for all groups was in acceptable levels. This study is the first attempt to provide information on the cancer risk of PAHs in drinking water from the Songhua River.     

Occurrence and sorption properties of arsenicals in marine sediments

The content of total arsenic, the inorganic forms: arsenite (As(III)) and arsenate (As(V)), the methylated forms: monomethylarsonic acid and dimethylarsinic acid (DMA), trimethylarsenic oxide, tetramethylarsenonium ion and arsenobetaine was measured in 95 sediment samples and 11 pore water samples from the Baltic Sea near the island of Bornholm at depths of up to 100 m. As(III+V) and DMA were detected in the sediment and As(III+V) was detected in the sediment pore water. Average total As concentration of 10.6?±?7.4 mg/kg dry matter (DM) in the sediment corresponds to previously reported values in the Baltic Sea and other parts of the world. Existing data for on-site measurements of sorption coefficients (Kd) of arsenicals in marine and freshwater sediments show large variability from <1 to >1,000 L/kg. In this work, calculated sorption coefficients (Kd and Koc) for As(III+V) showed significant correlation with depth, dissolved oxygen (DO), salinity and sediment classification; for depths <70 m, salinity <11 %, DO >9 mg/L and sand/silt/clay sediments the Kd was 118?±?76 L/kg DM and for depths >70 m, salinity >11 %, DO?<?9 mg/L and muddy sediments the Kd was 513?±?233 L/kg DM. The authors recommend using the found Kd value for arsenic in marine sediments when conditions are similar to the Baltic Sea. At locations with significant anthropogenic point sources or where the local geology contains volcanic rock and sulphide mineral deposits, there may be significantly elevated arsenic concentrations, and it is recommended to determine on-site Kd values.     

Occurrence,sources, and ecological risks of PBDEs,PCBs, OCPs,and PAHs in surface sediments of the Yangtze River Delta city cluster,China

Polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in 25 surface sediments in three cities (Nantong, Wuxi, and Suzhou) in the Yangtze River Delta, eastern China were measured. The mean concentrations were 378, 45.8, 1.98, 4,002 ng/g for PBDEs, OCPs, PCBs, and PAHs, respectively. Their levels in the sediments in the three cities were generally consistent with the city industrialization. PBDEs and OCPs were markedly dominated by deca-BDE (>90 %) and DDTs (>70 %). A principle component analysis of the analytes identified three major factors suggesting different sources of the contaminants in the sediments. PBDEs and the organic carbon in the sediments have common sources from industrial activities; whereas OCPs and PCBs, correlated with the second factor, were mainly from historical sources. The third factor with loadings of PAHs is indicative of various combustion sources. Ecological risk assessment indicated that the potential highest risk is from DDTs, for which 22 sites exceed the effects range low (ERL) values and three sites exceed the effects range median (ERM) value.     

Composition and source apportionment of PAHs in sediments at river mouths and channel in Kaohsiung Harbor, Taiwan

Fifty-eight sediment samples were collected in 2009 from the bottom of river mouths near Kaohsiung Harbor (Taiwan) and the harbor channel for the analyses of polycyclic aromatic hydrocarbons (PAHs) using gas chromatography-mass spectrometry (GC-MS). Concentrations of total PAHs varied from 39 to 30,521 ng g(-1) (dry weight); samples collected from the mouths of Love River, Canon River, Jen-Gen River, and Salt River showed the highest PAHs concentrations. This indicates that the major sources of sediment PAHs come from those polluted urban rivers and the harbor channel. In samples collected from the Salt River mouth, approximately 43% of the PAHs are identified as PAHs with 2 or 3 rings. However, samples collected from other locations contain predominantly PAHs with 4 rings (32 to 42%) or 5 and 6 rings (36 to 44%). Emissions from traffic-related sources and waste incineration contribute to the majority of PAHs found in most channel and river mouth sediments. However, coal/oil combustion is the main cause of high concentrations of PAHs observed in the Salt River mouth sediments. Principal component analyses with multivariate linear regression (PCA/MLR) have been used to further quantify the source contributions, and the results show that the contributions of coal/oil combustion, traffic-related and waste incineration are 37%, 33% and 30%, respectively.     

Development and application of microwave assisted extraction (MAE) for the extraction of five polycyclic aromatic hydrocarbons in sediment samples in Johannesburg area, South Africa

A microwave-assisted extraction (MAE) method was verified and applied for the extraction of polycyclic aromatic hydrocarbons (PAHs) in sediment samples. Soxhlet extraction was used as the reference method. The optimum MAE was carried out with 20 mL of hexane/acetone (1:1, v/v) mixture in a 1-g sample at 250 W for 20 min. Soxhlet extraction was carried out with 250 mL of dichloromethane:hexane (1:1, v/v) mixture in a 15-g sample for 24 h in a water bath maintained at 60 °C. The collected extracts were both cleaned up, reduced to 1 mL under nitrogen and then injected into an HPLC fluorescence. To increase the sample throughput, simultaneous MAE was performed. The obtained percentage recoveries ranged from 61 to 93 and 88–98 for MAE and SE, respectively. The optimised MAE method was validated using certified reference material. It was then applied to real sediment samples from in and around the greater Johannesburg area. The sediments from Jukskei River were found to be the most polluted while Hartbeespoort Dam sediments were found to be least polluted. The overall order of concentrations for the studied PAHs per site was as follows: Jukskei River?>?Kempton Park?>?Centurion Dams?>?Natalspruit River (PIT)?>?Hartbeespoort Dam.     

Levels of polycyclic aromatic hydrocarbons (PAHs) in the Densu River Basin of Ghana

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in Densu River Basin in Ghana were measured using gas chromatograph. Surface water samples were collected from nine stations, namely, Potroase, Koforidua Intake, Suhyien, Mangoase, Asuboi, Nsawam Bridge, Afuaman, Ashalaga, and Weija Intake in the Densu Basin. Total PAH concentrations varied from 13.0 to 80.0 ??g/mL in the Densu River, with a mean value of 37.1 ??g/mL. The two- to three-ring PAHs (low-molecular-weight PAHs) were found to be dominant in the Densu River Basin. Total PAH concentrations showed the following pattern: Koforidua Intake (80.0 ??g/mL) > Asuboi (50.8 ??g/mL) > Afuaman (47.9 ??g/mL) > Weija Intake (45.0 ??g/mL) > Suhyien (27.6 ??g/mL) > Nsawam (23.5 ??g/mL) > Ashalaja (22.9 ??g/mL) > Potroase (23.3 ??g/mL) > Mangoase (13.0 ??g/mL). According to the Agency for Toxic Substances and Disease Registry (ATSDR), background levels of PAHs in drinking water supplies in the USA range from 0.004 to 0.024 ??g/mL. PAH levels from all sites exceeded the range set by ATSDR. B[a]P contributed the highest carcinogenic exposure equivalent (0.3 ??g/mL), followed by B[a]A (0.132 ??g/mL) and B[b]F (0.08 ??g/mL), contributing 52.6%, 23.2%, and 4.6%, respectively, of the total carcinogenicity of surface water PAH in the Densu River Basin. The carcinogenic potency was estimated to be 0.57 ??g/mL. The presence of PAHs was an indication of the water sources being contaminated, with potential health implications.     

Comparison of different methods for extraction of polycyclic aromatic hydrocarbons (PAHs) from Sicilian (Italy) coastal area sediments

This paper describes a work aimed at improving the conditions of an extraction method, coupling GC-MS determination, for the analysis without cleanup phase, of polycyclic aromatic hydrocarbons (PAHs) from sediment samples. The automatic Soxhlet extraction in warm mode (using Extraction System B-811 Standard, Büchi) has demonstrated advantages for automation, reduced extraction time, and lower solvent use than for conventional Soxhlet extraction. Under these conditions, the recoveries are very good as they resulted greater than 85 % and, in most of the cases, near 100 %. The repeatability is also satisfactory (relative standard deviation less than 15 %). The detection limits are also acceptable and ranged from 0.001 to0.01 μg/kg dry weight. Fifty-four sediment samples were collected. The total concentration of the 17 compounds investigated, in samples of sediments collected from three Sicilian coastal areas, expressed as the sum of concentrations, varies from 99 to 11,557 μg/kg of dry matrix; concentrations of total PAHs in the sediments of Cala are two to three times higher than the other stations.