Evaluation of PLE exhaustiveness for the extraction of PCBs from sediments and the influence of sediment characteristics

Pressurized liquid extractions were performed on eight sediments in order to investigate if a modified US EPA method (100 °C, 100 bar, n-heptane/acetone (1:1), 2 × 5 min) provided exhaustive extractions of polychlorinated biphenyls (PCBs) from sediment, and to study if the extractability of PCBs from the different sediments was affected by characteristics of the sediment. The recovery from the eight native sediments, contaminated in nature, was between 96.4% and 98.9%, as an average of the recoveries from 10 PCB congeners. Hundred percent recovery was defined as the sum of two consecutive extractions (2 × 5 min each) at the stated conditions. The recoveries of the individual congeners were above 94%, except for one congener in one sediment, which had a recovery of 92%. When the recoveries and different characteristics of the sediments were compared, no correlation appeared between recoveries and sediment PCB concentration, total organic carbon (TOC), soot carbon (SC) or amorphous carbon (AC). The fact that carbon did not influence the extractions was somewhat surprising, since previous experiments have indicated a connection. Instead, statistically significant (p < 0.05) correlations were observed for water content and carbon/nitrogen (C/N) ratio. The decrease in recoveries with decreased water content was attributed to less access of the solvent to the analytes due to less matrix swelling. The lowered recoveries with increased C/N ratio can indicate that a difference in structure of the organic matter exists, which influences the binding strength between the analytes and the matrix. The difference in structure can possibly be explained by different origin of the organic matter or by aging effects. Overall the method was found to be exhaustive and the excellent recoveries show that sediment characteristics do not influence the extractions markedly.     

Bioremediation of PCB-contaminated sediments and evaluation of their pre- and post-treatment ecotoxicity

The paper deals with the application of two perspective and promising bioremediation approaches, bioaugmentation and biostimulation, applied to sediment contaminated with polychlo-rinated biphenyls (PCBs) with the aim to enhance biodegradation of PCBs. Sediments were sampled from Strá?sky canal, an industrial waste canal that flows from a former PCB-factory through the Laborec river into the Zemplínska ?írava water reservoir, all located in the eastern part of Slovakia. Bioaugmentation of sediments was performed in microcosms using two bacterial isolates with PCB-degradation ability obtained from the contaminated sediment: Achromobacter xylosoxidans, Stenotrophomonas maltophilia. Biostimulation was performed using an addition of cut plants containing terpenes, known as PCB-inducers (ivy leaves and pine needles). Ecotoxicity of the contaminated sediments was evaluated pre- and post-treatment using biotests of the standard aquatic plant Lemna minor, standard contact test using Lactuca sativa var. capitata, and the bioluminescent bacteria Vibrio fischeri. Biostimulation treatment using ivy leaves revealed higher degradation of detected PCB congeners than that achieved by the addition of pine needles, but moderately higher post-treatment toxicity of the sediment to the bioindicator Lemna minor.     

Radioactive contamination of the environment as a result of uranium production: a case study at the abandoned Lincang uranium mine, Yunnan Province, China

The distribution of radioactive pollutants, such as ~(222)Rn, U, Th and ~(226)Ra in the air, sur-face waters, soils and crops around the Lincang uranium mine, Yunnan Province, China, is studiedThe mechanical, geochemical and biogeochemical processes responsible for the transport andfate of the radioactive elements are discussed based on the monitoring data. The pollutants con-centrations of effluents from the mine tunnels were dependent on pH and SO_4~(2-) which were con-trolled by biochemical oxidation of sulfide in the ore/host rocks. Radon anomalies in air reached 4km from the tailings pile depending on radon release from the site, topography and climate. ~(238)Uand ~(226)Ra abnormities in stream sediments and soil were 40-90 cm deep and 790-800 m awaydownstream. Anomalies of radioactive contaminants of surface watercourses extended 7.5-13km from the discharge of effluents of the site mainly depending on mechanical and chemical proc-esses. There were about 2.86 ha rice fields and 1.59 km stream sediments contaminated. Erosionof tailings and mining debris with little or no containment or control accelerated the contaminationprocesses.     

Non-discriminating flash pyrolysis and thermochemolysis of heavily contaminated sediments from the Hamilton Harbor (Canada)

Analytical pyrolysis of sediments contaminated with pollutants of medium to high molecular weights (up to approximately 500 Da) is very challenging when using conventional pyrolysis systems due to discrimination of high molecular weight analytes. In the framework of this contribution, non-discriminating pyrolysis and thermochemolysis using rapid heating in a Silcosteel capillary were applied to study organic pollutants in heavily contaminated sediments taken from the Hamilton Harbor. The novel pyrolysis approach, requiring very small amounts of sample, turned out to be very useful as a rapid screening method, e.g. for risk assessment studies, proving superior to commonly used solvent extraction. Main pollutants in the sediments under study included aromatic hydrocarbons, chiefly originating from coal tar and petroleum. Polycyclic aromatic hydrocarbons (PAHs) beyond six-rings, including coronene and truxene, could be detected. Sequential tetramethyl ammonium hydroxide-induced thermochemolysis performed at 500 and 750 degrees C enabled the differentiation between organic pollutants sorbed onto the sediment matrix on the one hand, and structural moieties of the condensed polymeric humic sediment matrix along with bound residues on the other hand. Thermochemolysis at 500 degrees C removed sorbates quantitatively, leaving only bare polymeric humic matrix. Significant PAH source indicators provided evidence that the lipidic fraction sorbed onto the sediments originated from PAHs formed chiefly in coal combustion processes. The polymeric humic organic matter network of the less polluted sediment was mainly of petrogenic origin, whereas black carbon, kerogen, etc. contributed to the organic carbon of the heavily polluted sediment. Thermochemolysis at 500 degrees C was also used to study fatty acid profiles of the sediments. The fatty acid methyl ester patterns obtained for the two sites under study differed significantly, with strong indications that microbial attenuation of the pollutants at the heavily polluted site 2 was strongly suppressed.     

Comparison of GC-ECD,GC-MS and GC-AED for the determination of polychlorinated biphenyls in highly contaminated marine sediments

Summary Electron capture detection (ECD), low- and highresolution mass spectrometry (LR- and HRMS), and atomic emission detection (AED) were compared for the gas chromatographic (GC) detection of polychlorinated biphenyls (PCBs) present in highly contaminated marine sediments. With ECD, LRMS, and even HRMS, detection was seriously disturbed by the complex matrix of the sediments, whereas AED in the chlorine-selective mode provided excellent PCB profiles without interferences. In addition, GC-AED provided congener independent responses, which enabled accurate quantitation of all PCBs based on a single calibration curve. However, because GC-AED was less sensitive than the other techniques studied, preparation of relatively large amounts of sample (10–20 g dry sediment) was required for most analyses.     

Radioactive contamination of the environment as a result of uranium production: a case study at the abandoned Lincang uranium mine,Yunnan Province,China

The distribution of radioactive pollutants, such as²²²Rn, U, Th and²²⁶Ra in the air, surface waters, soils and crops around the Lincang uranium mine, Yunnan Province, China, is studied. The mechanical, geochemical and biogeochemical processes responsible for the transport and fate of the radioactive elements are discussed based on the monitoring data. The pollutants concentrations of effluents from the mine tunnels were dependent on pH and which were controlled by biochemical oxidation of sulfide in the ore/host rocks. Radon anomalies in air reached 4 km from the tailings pile depending on radon release from the site, topography and climate.²³⁸U and²²⁶Ra abnormities in stream sediments and soil were 40—90 cm deep and 790—800 m away downstream. Anomalies of radioactive contaminants of surface watercourses extended 7.5—13 km from the discharge of effluents of the site mainly depending on mechanical and chemical processes. There were about 2.86 ha rice fields and 1.59 km stream sediments contaminated. Erosion of tailings and mining debris with little or no containment or control accelerated the contamination processes.

     

Radioactive contamination of the environment as a result of uranium production: a case study at the abandoned Lincang uranium mine,Yunnan Province,China

The distribution of radioactive pollutants, such as²²²Rn, U, Th and²²⁶Ra in the air, surface waters, soils and crops around the Lincang uranium mine, Yunnan Province, China, is studied. The mechanical, geochemical and biogeochemical processes responsible for the transport and fate of the radioactive elements are discussed based on the monitoring data. The pollutants concentrations of effluents from the mine tunnels were dependent on pH and which were controlled by biochemical oxidation of sulfide in the ore/host rocks. Radon anomalies in air reached 4 km from the tailings pile depending on radon release from the site, topography and climate.²³⁸U and²²⁶Ra abnormities in stream sediments and soil were 40—90 cm deep and 790—800 m away downstream. Anomalies of radioactive contaminants of surface watercourses extended 7.5—13 km from the discharge of effluents of the site mainly depending on mechanical and chemical processes. There were about 2.86 ha rice fields and 1.59 km stream sediments contaminated. Erosion of tailings and mining debris with little or no containment or control accelerated the contamination processes.     

Determination of 4-nonylphenols in sediments from a eutrophic marine area

The aim of this work was to develop a simple and efficient analytical method for the determination of 4-nonylphenols (4-NPs) in marine sediments. Nonylphenols are a group of xenobiotics of great environmental concern owing to their endocrine-disrupting properties; they are recognised as priority pollutants by the Water Framework Directive. The analytical procedure involves ultrasonic extraction followed by two-step solid phase extraction clean-up and gas chromatography–mass spectrometry analysis, without a derivatisation step. The method was validated and demonstrated to be suitable for marine sediments rich in organic matter from a eutrophic, contaminated area; 4-NP recovery rates were above 90%. This method was applied to the analysis of 4-NPs in recent sediments from the Gulf of Gdańsk (Southern Baltic Sea). Sediments from this area are moderately contaminated with 4-NPs (0–1 cm layer: 1–42 ng/g d.w.; 1–5 cm layer: 2–61 ng/g d.w.).     

Adaptation and validation of QuEChERS method for the simultaneous analysis of priority and emerging pollutants in sediments by gas chromatography—mass spectrometry

A Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method has been adapted and validated for the simultaneous determination of priority (16 PAHs, 12 PCBs and 7 organochlorine pesticides (OCPs)) and emerging (carbamazepine, 9 musks and 6 sunscreens) pollutants in sediments by Gas Chromatography-Mass Spectrometry (GC-MS). The sample preparation was adapted by modifying the nature of the extraction solvent and optimising clean-up and evaporation steps. The method was validated by the analysis of spiked estuarine and marine sediments. Analytical performances were evaluated in terms of linearity, accuracy, precision and detection limits. The method shows good linearity (coefficients of determination > 0.998) and repeatability (RSD < 10%). Obtained recoveries are acceptable, ranging from 62% to 131% for all the compounds. Detection limits are estimated to range from 0.01 ng/g to 3.18 ng/g. This developed method offers the ability to detect and quantify several priority and emerging pollutants at low concentration levels in sediments.     

Microwave-assisted extraction of organochlorine compounds in marine sediments with organized molecular systems

Summary Analysis of marine sediments is particulary important because they are considered pollution indicators, since they present a view of the spatial distribution of pollutants. The use of microwave energy enables a simple and rapid analysis of different kinds of compounds present in these media. This work shows the results obtained during the optimization process for the application of microwave-assisted extraction methodology (MAE) to the determination of polychlorinated dibenzofurans (PCDFs), present in different marine sediment samples, as well as in mixtures with polychlorinated biphenyls (PCBs), using two non-ionic surfactants (oligoethylene glycol monoalkyl ether and polyoxyethylene 10 lauryl ether) as extractants. After extraction, the organochlorinated compounds are determined by HPLC using fluorescence detection. Recovery rates are compared with those obtained when Soxhlet extraction is used for the same purpose.     

Sensitive GC/MS determination of 15 isomers of chlorobenzoic acids in accelerated solvent extracts of soils historically contaminated with PCBs and validation of the entire method

Chlorobenzoic acids (CBAs) are the major metabolite of aerobic bacterial degradation of polychlorinated biphenyls (PCBs). A rapid and simple simultaneous derivatisation method has been developed for gas chromatography-mass spectrometry determination in historically PCB-contaminated soils for 15 isomers of mono-, di-, tri-, tetra-, and pentachlorobenzoic acids in CBA mixtures. Two derivatisation agents (diazomethane and methyl chloroformate) and various conditions were evaluated (temperature, time, solvents, catalysts) in terms of efficiency. The optimised derivatisation method with diazomethane and 1% methanol running 1 hour at 5°C was used for derivatisation of extracts of soils and river sediment from historically PCB-contaminated sites; the extracts were prepared using accelerated solvent extraction by a previously described method. Methylated CBAs were separated by gas chromatography using a system with two different common columns, DB-5 and DB-200, in series-coupled (tandem) arrangement and detected by EI-MS. A clean-up with a gel permeation chromatography was carried out to remove soil interfering matrix compounds as well as major portion of PCBs. The limits of quantification ranged between 1 and 10 ng g^?1 of individual CBA in the soil. The procedure was applied to various soil samples from Lhenice (Czech Republic) highly contaminated with PCBs. CBAs were found in all tested soils and also in the river sediment. The most contaminated soil contained all CBAs representatives under the study with a total concentration of 3.1 µg g^?1 of dry soil.     

Accumulation and efflux of polychlorinated biphenyls in Escherichia coli

Polychlorinated biphenyls (PCBs) are environmental pollutants that have been associated with numerous adverse health effects in human and animals. Hydroxylated PCBs (HPCBs) are the product of the oxidative metabolism of PCBs. The presence of hydroxyl groups in HPCBs makes these compounds more hydrophilic than the parent PCBs. One of the best approaches to break down and remove these contaminants is bioremediation; an environmentally friendly process that uses microorganisms to degrade hazardous chemicals into non-toxic ones. In this study, we investigated the cellular accumulation and toxicity of selected PCBs and HPCBs in Gram-negative bacteria, using Escherichia coli as a model organism. We found that none of the five PCBs tested were toxic to E. coli, presumably due to their limited bioavailability. Nevertheless, different HPCBs tested showed different levels of toxicity. Furthermore, we demonstrated that the primary multidrug efflux system in E. coli, AcrAB-TolC, facilitated the efflux of HPCBs out of the cell. Since AcrAB-TolC is constitutively expressed in E. coli and is conserved in all sequenced Gram-negative bacterial genomes, our results suggest that the efflux activities of multidrug resistant pumps may affect the accumulation and degradation of PCBs in Gram-negative bacteria.     

Correlation between static mechanical properties of starch-glycerol materials and low-temperature relaxation

Mechanical, calorimetric, dynamic mechanical and dielectric properties were measured in starch and amylose films plasticized by different glycerol contents. Low-temperature relaxation was found to be highly dependent on plasticizer level and related to unusual mechanical properties.     

Analysis of industrial contaminants in indoor air: Part 1. Volatile organic compounds,carbonyl compounds,polycyclic aromatic hydrocarbons and polychlorinated biphenyls

This article reviews recent literature on the analysis of industrial contaminants in indoor air in the framework of the REACH project, which is mainly intended to improve protection of human health and the environment from the risks of more than 34 millions of chemical substances. Industrial pollutants that can be found in indoor air may be of very different types and origin, belonging to the volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs) categories. Several compounds have been classified into the priority organic pollutants (POPs) class such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDD/PCDFs) and related polychlorinated compounds, and polycyclic aromatic hydrocarbons (PAHs). Many of these compounds are partially associated to the air gas phase, but also to the suspended particulate matter. Furthermore, settled dust can act as a concentrator for the less volatile pollutants and has become a matrix of great concern for indoors contamination. Main literature considered in this review are papers from the last 10 years reporting analytical developments and applications regarding VOCs, aldehydes and other carbonyls, PCBs, PCDDs, PCDFs, and PAHs in the indoor environment. Sample collection and pretreatment, analyte extraction, clean-up procedures, determination techniques, performance results, as well as compound concentrations in indoor samples, are summarized and discussed. Emergent contaminants and pesticides related to the industrial development that can be found in indoor air are reviewed in a second part in this volume.     

Optimisation of Pressurized Liquid Extraction for the Determination of Seven Selected Polychlorinated Biphenyls in Feed Samples

Pressurized Liquid Extraction was utilized for the extraction of seven selected polychlorinated biphenyls (28, 52, 101, 118, 153, and 180) from a naturally contaminated fishmeal and two feed samples fortified with a naturally contaminated fish oil sample. In order to assure sufficient extraction efficiencies, the extraction solvent, the extraction temperature, and the flush volume were optimised by a factorial design approach. The results of the analyses revealed that the impact of these parameters on the extraction of PCBs differed depending on which matrix that was analysed. For fishmeal, an elevated extraction temperature was important to obtain the highest values for the recovery rates whereas for the feed samples high extraction efficiencies could be obtained for all temperatures investigated in the study. In addition, the solvent had an impact on the extraction of PCBs, however, the influence was less pronounced than the impact of temperature. The final conditions, resulting in high recovery rates for all PCBs in all matrices, were found to be temperatures above 100°C using n-heptane as extraction solvent, while the flush volume had very limited effects on the extraction efficiency.     

Determination of semi-volatile priority pollutants in landfill leachates and sediments using microwave-assisted headspace solid-phase microextraction

The present work was focused on the development of a simple method aimed at the determination of 12 polycyclic aromatic hydrocarbons (PAHs) and 15 polychlorinated biphenyls (PCBs) in landfill leachates and sediments by adapting a domestic microwave oven to perform microwave-assisted headspace solid-phase microextraction (MA-HS-SPME) followed by gas chromatographic separation and tandem mass spectrometric detection. Good linearity was observed within the concentration range studied; detection limits ranged from 0.1 ng/l to 7 ng/l for PCBs and from 5 ng/l to 926 ng/l for PAHs. Concerning precision, the relative standard deviations obtained were, on average for the leachate and sediment samples analysed, 18% for PCBs and 20% for PAHs. Average recovery values were 37% and 76% for PCBs, and 58% and 48% for PAHs, respectively, for the leachate and reference sediment studied. The method allows the determination of PAHs and PCBs in landfill leachates and sediments, avoiding clean-up steps and the consumption of organic solvents.     

Feasibility of gas chromatography--ion trap tandem mass spectrometry for the determination of polychlorinated biphenyls in food

The different parameters affecting the ionisation and fragmentation of selected polychlorinated biphenyls (PCBs) in an IT detector working in the MS/MS mode, ITD(MS/MS), have been optimised for maximum selectivity and sensibility. The low LODs (in the range 0.03-0.3 microg/L), the satisfactory repeatability (RSDs in general below 11%) and reproducibility (RSDs below 17%) obtained when analysing standard solutions ensured proper determination of the PCBs studied at the concentrations typically found in food samples. Foodstuffs naturally contaminated with varying levels of PCBs have been analysed using the optimised GC-ITD(MS/MS) method. The results obtained compared favourably with those found using more conventional detectors, such as (micro-)electron capture detection (for ortho-PCBs) and high-resolution MS (for non-ortho-PCBs), as well as with the consensus PCB levels established for these particular samples via an international interlaboratory exercise. The relative merits of these three detectors have been discussed.     

Instrumental neutron activation analysis of extractable organohalogens in the Antarctic Weddell seal (<Emphasis Type="Italic">Leptonychotes weddelli</Emphasis>)

Instrumental neutron activation analysis (INAA) was performed for measurement of extractable organohalogens (EOX) in blubber samples of Weddell seals (Leptonychotes weddelli) from Antarctica. EOX were detected in all the analyzed samples. The concentration order of EOX was: extractable organochlorine (EOCl)>extractable organobromine (EOBr)>extractable organoiodine (EOI). Their levels increased gradually with aging as with other man-made persistent organic pollutants (POPs) such as PCBs and DDTs.     

Calorimetric investigation of complex formation of some humic compounds

In the present paper we studied the complexation capacity towards copper ion of fulvic acids extracted from Arno River and Lake Como sediments, as well as Antarctic Sea water at different pHs in order to evaluate the interaction of different complexing groups of fulvic acids with copper ions. The binding capacity studies were carried out by means of titration with a copper-selective electrode and calorimetric measurements. For the same purpose, the heat of reaction in the complexation of copper ions with small molecules containing functional groups similar to fulvic acid was also determined. Titration results indicated that the fraction of bound metal increases with increasing pH (from 5 to 7). This may be accounted for by the increase in the ionisation of the fulvic acid molecule. Results obtained from calorimetric measurements show that the quantity of total heat involved in the metal ion-fulvate interactions determines a decreasing exothermic response with increasing pH values. This revised version was published online in July 2006 with corrections to the Cover Date.