| 1. |
- Greis, Christina, 1975-, et al.
(författare)
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Plutonium remobilization in a humic-rich lake
- 2007
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 277:1, s. 265-268
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Tidskriftsartikel (refereegranskat)abstract
- Fresh water from Lake Svartsjön, Sweden, was collected and four fractions were prepared: (1) adsorption on DEAE, (2) flocculation with Ca2+, (3) co-precipitation with Fe hydrous oxide and (4) co-precipitation with Mn hydrous oxide. The plutonium level in the lake is 65 fg/l (222 μBq/l), measured by ICP-QMS and ICP-SFMS. Pronounced accumulation in fractions (1) (34%) and (2) (66%), combined with observed levels of organic matter indicate that plutonium is predominantly associated with organic matter. Measurements of isotopic ratios indicate that 77% of the plutonium originates from weapons testing and the remaining appears to originate from the Chernobyl accident.
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| 2. |
- Lacayo, Martha, et al.
(författare)
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Degradation of toxaphene by Bjerkandera sp. strain BOL13 using waste biomass as a cosubstrate
- 2006
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Ingår i: Applied Microbiology and Biotechnology. - : Springer Science and Business Media LLC. - 0175-7598 .- 1432-0614. ; 71:4, s. 549-554
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Tidskriftsartikel (refereegranskat)abstract
- The white-rot fungus Bjerkandera sp. strain BOL13 was capable of degrading toxaphene when supplied with wood chips, wheat husk or cane molasses as cosubstrates in batch culture experiments. Approximately 85% of toxaphene was removed when wheat husk was the main substrate. The production of lignin peroxidase was only stimulated when wheat husk was present in the liquid medium. Although xylanase was always detected, wheat husk supported the highest xylanase production. A negligible amount of beta-glucosidase and cellulase were found in the batch culture medium. To the best of our knowledge, this is the first reported case of toxaphene degradation by white-rot fungi.
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| 3. |
- Lacayo-Romero, Martha, et al.
(författare)
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Degradation of toxaphene in aged and freshly contaminated soil
- 2006
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 63:4, s. 609-615
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Tidskriftsartikel (refereegranskat)abstract
- Degradation of toxaphene in soil from both newly contaminated (from Sweden) and aged spills (from Nicaragua) were studied. The newly contaminated soil contained approximately 11 mg kg(-1) toxaphene while the aged Nicaraguan soil contained approximately 100 mg kg(-1). Degradation was studied in anaerobic bioreactors, some of which were supplied with lactic acid and others with Triton X-114. In this study we found that the lower isomers Parlar 11, 12 were degraded while the concentration of isomer Parlar 15 increased. This supported an earlier evaluation which indicated that less chlorinated isomers are formed from more heavily isomers. Lactic acid when added to the soil, interfere with the degradation of toxaphene. Lactic acid was added; several isomers appeared to degrade rather slowly in newly contaminated Swedish soil. The Swedish soil, without any external carbon source, showed the slowest degradation rate of all the compounds studied. When Triton X-114 at 0.4 mM was added, the degradation rate of the compounds increased. This study illustrates that biodegradation of toxaphene is a complex process and several parameters have to be taken into consideration. Degradation of persistent pollutants in the environment using biotechnology is dependent on bioavailability, carbon sources and formation of metabolites.
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| 4. |
- Lacayo, Martha, et al.
(författare)
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A toxaphene-degrading bacterium related to Enterobacter cloacae, strain D1 isolated from aged contaminated soil in Nicaragua
- 2005
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Ingår i: Systematic and Applied Microbiology. - : Elsevier BV. - 0723-2020 .- 1618-0984. ; 28:7, s. 632-639
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Tidskriftsartikel (refereegranskat)abstract
- Enterobacter sp. strain D1 is a facultative anaerobic, Gram-negative heterotrophic bacterium isolated from toxaphene-contaminated soil. This organism was identified and characterized through phylogenetic and taxonomic studies. Based on 16S rDNA analysis, the strain D1 was clustered closely with the species Enterobacter cloacae subsp. dissolvens (LMG 2683) and E. cloacae (ATCC 13047T). Strain D1 resembled these E. cloacae strains with respect to various biochemical and nutritional characteristics, but also exhibited differences. Moreover, strain D1 is able to grow and survive with toxaphene supplied in the medium in the range 3-96 mg/L. Amongst the chemical components of toxaphene, octachlorocamphenes, nonachlorobornanes and decachlorobornanes were seen to be rapidly metabolized, although levels of hexachlorocamphenes and heptachlorobornanes were found to be slowly degraded, and subsequently accumulated during the last stage of the cultivation.
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| 5. |
- Jakobsson, Kristina, et al.
(författare)
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Polybrominated diphenyl ethers in maternal serum, umbilical cord serum, colostrum and mature breast milk : Insights from a pilot study and the literature
- 2012
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 47, s. 121-130
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Tidskriftsartikel (refereegranskat)abstract
- Human serum and mother's milk are frequently used to assess exposure to polybrominated diphenyl ethers (PBDEs), including transplacental transfer to the foetus. However, little is known about the kinetics of PBDEs, especially the highly brominated BDE congeners.In this pilot study, maternal serum samples were collected from 10 women at delivery and five to six weeks post partum. Umbilical serum was also obtained. Milk was donated two to five days, and five to six weeks after delivery. The amount of PBDEs in these samples was determined using liquid–liquid extraction and GC/MS.Low, moderately and highly brominated diphenyl ethers were present in umbilical cord serum, indicating placental transfer. The lipid-adjusted levels of BDE-47, BDE-207 and BDE-209 were similar in maternal and umbilical cord serum, whereas the cord serum levels for the penta- to octa-BDEs quantified were lower than in maternal serum.Marked changes were seen in the congener pattern in breast milk during the first month of lactation, whereas maternal serum levels did not change significantly. The general pattern was an enrichment of low to moderately brominated congeners (i.e. from BDE-17 to BDE-154, with the exception of BDE-28) in colostrum compared with maternal serum. In contrast, more highly brominated congeners were found at similar, or lower levels in colostrum than in maternal serum. After the transition from colostrum to mature milk, the levels of BDE-153 and BDE-209 were substantially reduced, and BDE‐209 was below the limit of detection in 6 out of 9 samples.A literature review on the design and reporting of studies on the transfer of PBDEs from mother to infant revealed a lack of transparency in many cases. The use of the recently published STROBE-ME guidelines is therefore recommended.
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| 6. |
- Rydén, Andreas, 1981-, et al.
(författare)
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Synthesis and tentative identification of novel polybrominated diphenyl ether metabolites in human blood
- 2012
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 88:10, s. 1227-1234
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Tidskriftsartikel (refereegranskat)abstract
- Hydroxylated polybrominated diphenyl ethers (OH-PDBEs) are exogenous, bioactive compounds that originate, to a large extent, from anthropogenic activities, although they are also naturally produced in the environment. In the present study nine new authentic OH-PBDE reference standards and their corresponding methyl ether derivatives (MeO-PBDEs) were synthesised and characterised by NMR spectroscopy and mass spectrometry. Seven of the authentic reference standards prepared were thereafter tentatively identified in a pooled human blood sample. The tentatively identified OH-PBDEs were 3-hydroxy-2,2',4,4',6-pentabromodiphenyl ether, 3'-hydroxy-2,2',4,4',6-pentabromodiphenyl ether, 3-hydroxy-2,2',4,4',5-pentabromodiphenyl ether, 3-hydroxy-2,2',4,4',5,6'-hexabromodiphenyl ether. 3'-hydroxy-2,2',4,4',5,6'-hexabromodiphenyl ether, 3-hydroxy-2,2',4,4',5,5'-hexabromodiphenyl ether and 4-hydroxy-2,2',3,4',5,5',6-heptabromodiphenyl ether. An additional seven OH-PBDEs were tentatively identified in the pooled human blood sample, of which one OH-PBDE, 4'-hydroxy-2,2',4,5,5'-pentabromodiphenyl ether, has not been identified in human blood before. The identification was performed using gas chromatography-mass spectrometry (GC-MS) recording the bromine ions m/z 79, 81. The tentative identification was supported by the peaks relative retention times (RRTs) compared to authentic references on two GC columns of different polarities for the hexa-, and heptabrominated OH-PBDEs, and three different GC columns for the pentabrominated OH-PBDEs. The OH-PBDE congeners most likely originate from human metabolism of a flame retardant, i.e. polybrominated diphenyl ethers (PBDEs), due to the relatively high concentrations of PBDEs in the same human blood sample and the fact that these PBDEs could form the tentatively identified OH-PBDEs via metabolic direct hydroxylation or via 1,2-shift.
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| 7. |
- Barri, Thaer
(författare)
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Miniaturized, Membrane-Based and Environmentally Green Sample Preparation Systems: Applications for Biological and Environmental Aqueous Samples
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Contemporary advancements in miniaturization of analytical systems have advantageously fostered development, automation, and hyphenation of a variety of sample preparation techniques. Among several downscaled extraction designs, porous synthetic polymeric membranes (such as flat sheet (FS) or hollow fiber (HF)) have been utilized for membrane-based extraction, separating two aqueous phases (as in supported liquid membrane (SLM) extraction or one aqueous phase and another organic phase (as in microporous membrane liquid-liquid extraction (MMLLE)). The SLM and MMLLE configurations permit usage of microliter-volumes of extraction solvent, and therefore, are considered to be environmentally friendly. This dissertation addresses miniaturized membrane-based extraction techniques that were operated in automated, flowing, and on-line fashion as well as in nonautomated, nonflowing, and off-line setups. These environmentally green systems based on SLM and MMLLE were appraised for trace extraction of organic compounds (such as basic and acidic pharmaceuticals (by SLM), and PCBs, OCPs, and PBDEs (by MMLLE)) in environmental and biological aqueous samples. Exhaustive extraction and non-depletive equilibrium extraction exhibiting high level of analyte preconcentration were demonstrated. The former was performed for total analyte recovery. The later was pursued so as to quantify free analyte concentration in a sample containing an analyte and a binding phase, such as a protein or humic acids. For instance, by measuring the free drug concentration, the level of drug-protein binding (DPB) was quantitatively estimated as well as the DPB process was characterized and interpreted by obtaining the binding parameters from Scatchard and Bjerrum plots. The results revealed that, although the flowing on-line systems exhibited excellent performance (e.g. the Extracting Syringe device permitting a full automation of a µMMLLE with an on-line hyphenation to gas chromatography in a closed system and limits of detection at very low ng L-1 concentration level), the flowing systems suffered from setup complexity, low extraction efficiency, and problems with analyte carryover and adsorption. By contrast, the nonautomated nonflowing designs allowed simplified and easy-to-use procedures, high analyte extraction efficiency and enrichment, and no carryover and no adsorption problems as the HF-SLM or HF-MMLLE device was employed for only a single use. In conclusion, the HF-based, nonautomated, and nonflowing setups of SLM and MMLLE have been shown to have attractive merits when employed for exhaustive as well as non-depletive equilibrium sampling. The latter design has strong potential applications for speciation of freely dissolved organic compounds, and a promising development is expected in its application for environmental and biological samples.
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| 8. |
- Bergström, Staffan
(författare)
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Strategy for Monitoring Organic Pollutants in Waste Water with Focus on Improved Sample Preparation
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Strategy and methodology is presented for the analysis of organic pollutants, with the purpose of evaluating treatment procedures for landfill leachate. Today, many investigations of treatment procedures are focusing on the measurement of water quality parameters such as chemical and biochemical oxygen demand, (COD and BOD), and total organic carbon, (TOC) when assessing the organic compounds in waste waters. These parameters give an unclear picture of the actual organic constituents. A developed analytical protocol, the Laqua protocol, covers several classes of organic contaminants, including both polar and non-polar markers, as well as inorganic parameters. As markers for polar compounds some phenols are selected and for non-polar markers polychlorinated biphenyls (PCB) and polybrominated diphenylethers (PBDE) are used. Unidentified markers are also followed to back up trends. The monitoring of individual compounds gave valuable information in understanding the processes in the treatment procedures. A toxicity test suitable for leachate water based on the crustacean Artemia Salina was also developed and included in the evaluation protocol. Combined with a simple fractionation of the leachate water, this test gave valuable information about the origin of the toxicity, which mainly originated from ammonium. The protocol was implemented and tested on a pilot plant for different treatment procedures in Kristianstad, Sweden. The bottle neck in the complicated analysis of organic pollutants is the expensive and resource demanding sample preparation step. In this thesis focus has been on developing automated, cost effective analytical procedures with sample preparation based on membrane technology. For PCBs, phthalates and organochlorine pesticides (OCP), automated procedures have been based on membrane-GC methodology, and for phenols an automated system, based on membrane-LC methodology, has been developed. A simple very efficient method based on disposable hollow fibre has been developed for the analysis of PBDE with GC-MS for final determination. All the developed methods dramatically decrease the time and effort spent on sample preparation, and demand only a very small fraction of organic solvents compared to conventional methods. The developed methods have very good performance, and as an example PCB extracted from 1 ml sample in 10 minutes gave detection limits of 2 - 3 ng/l, and relative standard deviations (RSD) at 0.1 µg/l of 1.6 - 5.0 % for all ten PCB congeners investigated.
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| 9. |
- Reichenberg, Fredrik
(författare)
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The accessibility and chemical activity of polycyclic aromatic hydrocarbons in soil
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis proposes the use of two concepts: accessibility and chemical activity. Accessibility describes the mass quantity of PAHs that is or can become available within a given time span and under given conditions. Chemical activity quantifies the energetic state of the PAHs that determines the potential for spontaneous physicochemical processes, such as diffusion and partitioning. Chemical activity is closely related to fugacity and freely dissolved concentrations. Accessibility and chemical activity jointly govern the physicochemical part of what is known as bioavailability. Five (I-V) accompanying papers are discussed and elaborated. Paper I, is a general account of the two concepts as useful and measurable. Paper II describes a method to measure the chemical activity of PAHs in soil. Paper III is a case study; the accessibility and chemical activity of some PAHs found in a former industrial site soil were measured. Paper IV makes progress in the methodology of calibrating equilibrium sampling devices. Paper V is another case study, concerning PAHs in a highway roadside soil.
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| 10. |
- Westbom, Rikard
(författare)
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Development of Fast, Quantitative, Selective and Bioavailability-Predictive Extraction Procedures for Determination of Halogenated POPs in Environmental Matrices
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis concerns the analysis of anthropogenic substances of the compound class known as persistent organic pollutants (POPs). Sample preparation perspectives for the analysis of POPs in the environmental matrices water, soils and sediments are presented. This thesis features reasonably cheap and uncomplicated methodology capable of fast screening of POPs. It displays how quantitative extraction of POPs can be made in a sustainable manner and how selectivity can be increased generating faster and less solvent consuming procedures compared to common practice. Also demonstrated is the potential of how selective SFE can be used in bioavailability-predictive extractions. This fast and uncomplicated methodology is capable of generating information enhancing the quality and credibility of risk assessment procedures at contaminated sites. Furthermore, the possibility of environmental analytical chemistry of POPs becoming green chemistry is been highlighted throughout the text.
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