| 1. |
- Adolfsson-Erici, Margaretha, et al.
(författare)
-
A flow-through passive dosing system for continuously supplying aqueous solutions of hydrophobic chemicals to bioconcentration and aquatic toxicity tests
- 2012
-
Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 86:6, s. 593-599
-
Tidskriftsartikel (refereegranskat)abstract
- A continuous supply of water with defined stable concentrations of hydrophobic chemicals is a requirement in a range of laboratory tests such as the OECD 305 protocol for determining the bioconcentration factor in fish. Satisfying this requirement continues to be a challenge, particularly for hydrophobic chemicals. Here we present a novel solution based on equilibrium passive dosing. It employs a commercially available unit consisting of similar to 16000 polydimethylsiloxane (PDMS) tubes connected to two manifolds. The chemicals are loaded into the unit by repeatedly perfusing it with a methanol solution of the substances that is progressively diluted with water. Thereafter the unit is perfused with water and the chemicals partition from the unit into the water. The system was tested with nine chemicals with logK(ow) ranging from 4.1 to 6.3. The aqueous concentrations generated were shown to be largely independent of the water flow rate, and the unit to unit reproducibility was within a factor of similar to 2. In continuous flow experiments the aqueous concentrations of most of the study chemicals remained constant over 8 d. A model was assembled that allows prediction of the operating characteristics of the system from the logKow or PDMS/water partition coefficient of the chemical. The system is a simple, safe, predictable and flexible tool that generates stable aqueous concentrations of hydrophobic chemicals.
|
|
| 2. |
- Ahmadi, Hamid, et al.
(författare)
-
Mass transfer of hydrophobic organic chemicals between siliconesheets and through plant leaves and low-density polyethylene
- 2016
-
Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 164, s. 683-690
-
Tidskriftsartikel (refereegranskat)abstract
- Plant leaves play an important role in the fate of hydrophobic organic contaminants (HOCs) in theenvironment. Yet much remains unknown about the permeability of leaves by HOCs. In this pilot studywe measured (i) the kinetics of mass transfer of three polycyclic aromatic hydrocarbons (PAHs) and sixpolychlorinated biphenyls between a spiked and an unspiked sheet of polydimethylsiloxane (PDMS) indirect contact with each other for 24 h and (ii) kinetics of mass transfer of two PAHs through leaves andlow-density polyethylene (LDPE) in a passive dosing experiment by inserting these matrices between thetwo sheets of PDMS for 48 h. The kinetics of mass transfer of fluoranthene between PDMS sheets in directcontact were a factor of 12 slower than those reported in the literature. The kinetics of mass transfer offluorene and phenanthrene through leaves were within the range of those previously reported for 2,4-dichlorophenoxyacetic acid through isolated cuticles. Our results provide a proof-of-concept demon-stration that the passive dosing method applied in this study can be used to measure the mass transfercoefficients of organic chemicals through leaves. Key recommendations for future experiments are toload the PDMS at the highest feasible concentrations to avoid working at analyte levels close to the limitof detection, to keep the leaves moist and to minimize potential pathways for contamination of the PDMSsheets by exposure to laboratory air.
|
|
| 3. |
- Arp, Hans Peter H., et al.
(författare)
-
Weathering Plastics as a Planetary Boundary Threat : Exposure, Fate, and Hazards
- 2021
-
Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 55:11, s. 7246-7255
-
Tidskriftsartikel (refereegranskat)abstract
- We described in 2017 how weathering plastic litter in the marine environment fulfils two of three criteria to impose a planetary boundary threat related to chemical pollution and the release of novel entities: (1) planetary-scale exposure, which (2) is not readily reversible. Whether marine plastics meet the third criterion, (3) eliciting a disruptive impact on vital earth system processes, was uncertain. Since then, several important discoveries have been made to motivate a re-evaluation. A key issue is if weathering macroplastics, microplastics, nanoplastics, and their leachates have an inherently higher potential to elicit adverse effects than natural particles of the same size. We summarize novel findings related to weathering plastic in the context of the planetary boundary threat criteria that demonstrate (1) increasing exposure, (2) fate processes leading to poorly reversible pollution, and (3) (eco)toxicological hazards and their thresholds. We provide evidence that the third criterion could be fulfilled for weathering plastics in sensitive environments and therefore conclude that weathering plastics pose a planetary boundary threat. We suggest future research priorities to better understand (eco)toxicological hazards modulated by increasing exposure and continuous weathering processes, to better parametrize the planetary boundary threshold for plastic pollution.
|
|
| 4. |
|
|
| 5. |
- Bolinius, Dämien Johann, et al.
(författare)
-
A passive dosing method to determine fugacitycapacities and partitioning properties of leaves
- 2016
-
Ingår i: Environmental Science. - : Royal Society of Chemistry (RSC). - 2050-7887 .- 2050-7895. ; 18, s. 1325-1332
-
Tidskriftsartikel (refereegranskat)abstract
- The capacity of leaves to take up chemicals from the atmosphere and water in fl uences how contaminantsare transferred into food webs and soil. We provide a proof of concept of a passive dosing method tomeasure leaf/polydimethylsiloxane partition ratios ( K leaf/PDMS ) for intact leaves, using polychlorinatedbiphenyls (PCBs) as model chemicals. Rhododendron leaves held in contact with PCB-loaded PDMSreached between 76 and 99% of equilibrium within 4 days for PCBs 3, 4, 28, 52, 101, 118, 138 and 180.Equilibrium K leaf/PDMS extrapolated from the uptake kinetics measured over 4 days ranged from 0.075(PCB 180) to 0.371 (PCB 3). The K leaf/PDMS data can readily be converted to fugacity capacities of leaves( Z leaf ) and subsequently leaf/water or leaf/air partition ratios ( K leaf/water and K leaf/air ) using partitioning datafrom the literature. Results of our measurements are within the variability observed for plant/air partitionratios ( K plant/air ) found in the literature. Log K leaf/air from this study ranged from 5.00 (PCB 3) to 8.30(PCB 180) compared to log K plant/air of 3.31 (PCB 3) to 8.88 (PCB 180) found in the literature. The methodwe describe could provide data to characterize the variability in sorptive capacities of leaves that wouldimprove descriptions of uptake of chemicals by leaves in multimedia fate models.
|
|
| 6. |
- Bolinius, Damien Johann, et al.
(författare)
-
Comparison of eddy covariance and modified Bowen ratio methods for measuring gas fluxes and implications for measuring fluxes of persistent organic pollutants
- 2016
-
Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 16:8, s. 5315-5322
-
Tidskriftsartikel (refereegranskat)abstract
- Semi-volatile persistent organic pollutants (POPs) cycle between the atmosphere and terrestrial surfaces; however measuring fluxes of POPs between the atmosphere and other media is challenging. Sampling times of hours to days are required to accurately measure trace concentrations of POPs in the atmosphere, which rules out the use of eddy covariance techniques that are used to measure gas fluxes of major air pollutants. An alternative, the modified Bowen ratio (MBR) method, has been used instead. In this study we used data from FLUXNET for CO2 and water vapor (H2O) to compare fluxes measured by eddy covariance to fluxes measured with the MBR method using vertical concentration gradients in air derived from averaged data that simulate the long sampling times typically required to measure POPs. When concentration gradients are strong and fluxes are unidirectional, the MBR method and the eddy covariance method agree within a factor of 3 for CO2, and within a factor of 10 for H2O. To remain within the range of applicability of the MBR method, field studies should be carried out under conditions such that the direction of net flux does not change during the sampling period. If that condition is met, then the performance of the MBR method is neither strongly affected by the length of sample duration nor the use of a fixed value for the transfer coefficient.
|
|
| 7. |
- Bolinius, Damien Johann, 1989-
(författare)
-
Methods to measure mass transfer kinetics, partition ratios and atmospheric fluxes of organic chemicals in forest systems
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Vegetation plays an important role in the partitioning, transport and fate of hydrophobic organic contaminants (HOCs) in the environment. This thesis aimed at addressing two key knowledge gaps in our understanding of how plants exchange HOCs with the atmosphere: (1) To improve our understanding of the uptake of HOCs into, and transfer through, leaves of different plant species which can significantly influence the transport and fate of HOCs in the environment; and (2) To evaluate an experimental approach to measure fluxes of HOCs in the field. The methods presented in papers I, II and III contribute to increasing our understanding of the fate and transport of HOCs in leaves by offering straightforward ways of measuring mass transfer coefficients through leaves and partition ratios of HOCs between leaves, leaf lipids and lipid standards and reference materials like water, air and olive oil. The passive dosing study in paper III in particular investigated the role of the composition of the organic matter extracted from leaves in determining the capacity of the leaves to hold chemicals and found no large differences between 7 different plant species, even though literature data on leaf/air partition ratios (Kleaf/air) varies over 1-3 orders of magnitude. In paper IV we demonstrated that the modified Bowen ratio method can be extended to measure fluxes of persistent organic pollutants (POPs) if the fluxes do not change direction over the course of the sampling period and are large enough to be measured. This approach thus makes it possible to measure fluxes of POPs that usually require sampling times of days to weeks to exceed method detection limits. The experimental methods described in this thesis have the potential to support improved parameterization of multimedia models, which can then be evaluated against fluxes measured in the field using the modified Bowen ratio approach.
|
|
| 8. |
- Bolinius, Damien Johann, et al.
(författare)
-
Sorptive Capacities of Nonpolymeric Plant Lipids for Hydrophobic Chemicals Determined by Passive Dosing
- 2019
-
Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 53:3, s. 1278-1286
-
Tidskriftsartikel (refereegranskat)abstract
- Vegetation plays an important role in the partitioning, transport, and fate of semivolatile hydrophobic organic chemicals (HOCs) in the environment. Leaf/air partition ratios (K-leaf/air) of HOCs are highly variable for different plant species. The differences cannot be fully explained by the fraction of lipids in the leaves or the thickness of the cuticle. Our goal was to elucidate the importance of non polymeric lipids in determining K-leaf/air To do this, we extracted organic matter from 7 plant species using solvents that do not extract the polymeric lipids cutin and cutan, to yield extractable organic matter (EOM). We used passive dosing to determine the partition ratios of selected HOCs between the EOM of the leaves and our reference lipid, olive oil (K-EOM/olive oil) In addition, we measured analogous partition ratios for three lipid standards. Proton nuclear magnetic resonance (NMR) spectroscopy was used to characterize the composition of lipids. Differences in K-EOM/olive oil of two polychlorinated biphenyls and four chlorinated benzenes were below a factor of 2 in the plant species studied, indicating that the reported differences in K-leaf/air are not caused by differences in the sorptive capacities of nonpolymeric lipids or that our EOM is not representative of all nonpolymeric leaf lipids.
|
|
| 9. |
|
|
| 10. |
|
|
| 11. |
- Jahnke, Annika, et al.
(författare)
-
Differences between Lipids Extracted from Five Species Are Not Sufficient To Explain Biomagnification of Nonpolar Organic Chemicals
- 2015
-
Ingår i: Environmental Science and Technology Letters. - : American Chemical Society (ACS). - 2328-8930. ; 2:7, s. 193-197
-
Tidskriftsartikel (refereegranskat)abstract
- Lipids are the major sorptive phase for many organic chemicals that bioaccumulate in foodwebs. However, lipids are usually operationally defined by the extraction protocol. Large differences in sorptive capacities between species would violate assumptions implicit in widely used lipid-normalization procedures and invalidate generic bioaccumulation factors. We extracted lipids from five species from different trophic levels and domains and determined fractions of triglycerides, phospholipids, and cholesterol. We passively dosed the lipids with cyclic volatile methylsiloxanes and chlorobenzenes via headspace from spiked olive oil to determine their sorptive capacities. Lipids from seal blubber and pork bacon solely composed of triglycerides had capacities similar to that of olive oil; lipids from mussels, herring, and guillemot egg had quantifiable fractions of phospholipids and cholesterol and showed capacities reduced by factors of up to 2.3-fold. Generally, the sorptive capacities of the lipids were not elevated relative to the olive oil controls and are unlikely to explain a substantial part of biomagnification.
|
|
| 12. |
- Jahnke, Annika, et al.
(författare)
-
Do complex matrices modify the sorptive properties of polydimethylsiloxane (PDMS) for non-polar organic chemicals?
- 2010
-
Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1217:29, s. 4765-4770
-
Tidskriftsartikel (refereegranskat)abstract
- The partitioning of non-polar analytes into the silicone polydimethylsiloxane (PDMS) is the basis for many analytical approaches such as solid phase microextraction (SPME), stir bar sorptive extraction (SBSE) and environmental passive sampling. Recently, the methods have been applied to increasingly complex sample matrices. The present work investigated the possible effect of complex matrices on the sorptive properties of PDMS. First, SPME fibers with a 30 mu m PDMS coating were immersed in 15 different matrices, including sediment, suspensions of soil and humic substances, mayonnaise, meat, fish, olive oil and fish oil. Second, the surface of the fibers was wiped clean, and together with matrix-free control fibers, they were exposed via headspace to 7 non-polar halogenated organic chemicals in spiked olive oil. The fibers were then solvent-extracted, analyzed, and the ratios of the mean concentrations in the matrix-immersed fibers to the control fibers were determined for all matrices. These ratios ranged from 92% to 112% for the four analytes with the highest analytical precision (i.e. polychlorinated biphenyls (PCBs) 3, 28, 52 and brominated diphenyl ether (BDE) 3), and they ranged from 74% to 133% for the other three compounds (i.e. PCBs 101.105 and gamma-hexachlorocyclohexane (HCH)). We conclude that, for non-polar, hydrophobic chemicals, the sorptive properties of the PDMS were not modified by the diverse investigated media and consequently that PDMS is suited for sampling of these analytes even in highly complex matrices.
|
|
| 13. |
- Jahnke, Annika, et al.
(författare)
-
Emerging investigator series : effect-based characterization of mixtures of environmental pollutants in diverse sediments
- 2018
-
Ingår i: Environmental Science. - : Royal Society of Chemistry (RSC). - 2050-7887 .- 2050-7895. ; 20:12, s. 1667-1679
-
Tidskriftsartikel (refereegranskat)abstract
- This study investigated whether cell-based bioassays were suitable to characterize profiles of mixture effects of hydrophobic pollutants in multiple sediments covering remote Arctic and tropical sites to highly populated sites in Europe and Australia. The total contamination was determined after total solvent extraction and the bioavailable contamination after silicone-based passive equilibrium sampling. In addition to cytotoxicity, we observed specific responses in cell-based reporter gene bioassays: activation of metabolic enzymes (arylhydrocarbon receptor: AhR, peroxisome proliferator activated receptor gamma: PPAR) and adaptive stress responses (oxidative stress response: AREc32). No mixture effects were found for effects on the estrogen, androgen, progesterone and glucocorticoid receptors, or they were masked by cytotoxicity. The bioanalytical equivalent concentrations (BEQ) spanned several orders of magnitude for each bioassay. The bioavailable BEQs (passive equilibrium sampling) typically were 10-100 times and up to 420 times lower than the total BEQ (solvent extraction) for the AhR and AREc32 assays, indicating that the readily desorbing fraction of the bioactive chemicals was substantially lower than the fraction bound strongly to the sediment sorptive phases. Contrarily, the bioavailable BEQ in the PPAR assay was within a factor of five of the total BEQ. We identified several hotspots of contamination in Europe and established background contamination levels in the Arctic and Australia.
|
|
| 14. |
- Jahnke, Annika, et al.
(författare)
-
EQUILIBRIUM SAMPLING OF ENVIRONMENTAL POLLUTANTS IN FISH : COMPARISON WITH LIPID-NORMALIZED CONCENTRATIONS AND HOMOGENIZATION EFFECTS ON CHEMICAL ACTIVITY
- 2011
-
Ingår i: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 30:7, s. 1515-1521
-
Tidskriftsartikel (refereegranskat)abstract
- Equilibrium sampling of organic pollutants into the silicone polydimethylsiloxane (PDMS) has recently been applied in biological tissues including fish. Pollutant concentrations in PDMS can then be multiplied with lipid/PDMS distribution coefficients (D(Lipid.PDMS)) to obtain concentrations in fish lipids. In the present study, PDMS thin films were used for equilibrium sampling of polychlorinated biphenyls (PCBs) in intact tissue of two eels and one salmon. A classical exhaustive extraction technique to determine lipid-normalized PCB concentrations, which assigns the body burden of the chemical to the lipid fraction of the fish, was additionally applied. Lipid-based PCB concentrations obtained by equilibrium sampling were 85 to 106% (Norwegian Atlantic salmon), 108 to 128% (Baltic Sea eel), and 51 to 83% (Finnish lake eel) of those determined using total extraction. This supports the validity of the equilibrium sampling technique, while at the same time confirming that the fugacity capacity of these lipid-rich tissues for PCBs was dominated by the lipid fraction. Equilibrium sampling was also applied to homogenates of the same fish tissues. The PCB concentrations in the PDMS were 1.2 to 2.0 times higher in the homogenates (statistically significant in 18 of 21 cases, p < 0.05), indicating that homogenization increased the chemical activity of the PCBs and decreased the fugacity capacity of the tissue. This observation has implications for equilibrium sampling and partition coefficients determined using tissue homogenates.
|
|
| 15. |
- Jahnke, Annika, et al.
(författare)
-
Equilibrium Sampling to Determine the Thermodynamic Potential for Bioaccumulation of Persistent Organic Pollutants from Sediment
- 2014
-
Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 48:19, s. 11352-11359
-
Tidskriftsartikel (refereegranskat)abstract
- Equilibrium partitioning (EqP) theory is currently the most widely used approach for linking sediment pollution by persistent hydrophobic organic chemicals to bioaccumulation. Most applications of the EqP approach assume (I) a generic relationship between organic carbon-normalized chemical concentrations in sediments and lipid-normalized concentrations in biota and (II) that bioaccumulation does not induce levels exceeding those expected from equilibrium partitioning. Here, we demonstrate that assumption I can be obviated by equilibrating a silicone sampler with chemicals in sediment, measuring chemical concentrations in the silicone, and applying lipid/silicone partition ratios to yield concentrations in lipid at thermodynamic equilibrium with the sediment (C-Lip(sic)Sed). Furthermore, we evaluated the validity of assumption II by comparing C-Lip(sic)Sed of selected persistent, bioaccumulative and toxic pollutants (polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB)) to lipid-normalized concentrations for a range of biota from a Swedish background lake. PCBs in duck mussels, roach, eel, pikeperch, perch and pike were mostly below the equilibrium partitioning level relative to the sediment, i.e., lipid-normalized concentrations were <= C-Lip(sic)Sed, whereas HCB was near equilibrium between biota and sediment. Equilibrium sampling allows straightforward, sensitive and precise measurement of C-Lip(sic)Sed. We propose C-Lip(sic)Sed as a metric of the thermodynamic potential for bioaccumulation of persistent organic chemicals from sediment useful to prioritize management actions to remediate contaminated sites.
|
|
| 16. |
|
|
| 17. |
|
|
| 18. |
- Jahnke, Annika, et al.
(författare)
-
Possibilities and limitations of equilibrium sampling using polydimethylsiloxane in fish tissue.
- 2009
-
Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 77:6, s. 764-70
-
Tidskriftsartikel (refereegranskat)abstract
- Polydimethylsiloxane (PDMS) has been used for passive equilibrium sampling in numerous abiotic environmental matrices. Recently, this approach was extended to lipid-rich tissue. This work investigated the possibilities and limitations of using PDMS thin-film extraction for in tissue equilibrium sampling in fish species of varying lipid content. Polychlorinated biphenyls (PCBs) were used as model lipophilic organic pollutants. PDMS thin-films were inserted in intact fish tissue for differing time periods (1h up to 1 week). The thin-films were then solvent-extracted and the extracts were analyzed using gas chromatography coupled to mass spectrometry. Whether equilibrium had been established was investigated either by using PDMS thin-films of multiple thicknesses (140-620 microm) or by assessing kinetics by means of time series. Equilibration was found to be rapid (i.e. in the range of hours) in lipid-rich fish whereas equilibrium was not achieved within one week in tissues with low or medium lipid content (i.e. up to 2% lipids). Regarding lipid-rich fish, the newly developed method was found to be sufficiently sensitive to determine equilibrium partitioning concentrations of PCBs in lipids of samples from the Baltic Sea, and it is a promising approach for any kind of fatty tissue.
|
|
| 19. |
- Jahnke, Annika, et al.
(författare)
-
Quantitative trace analysis of polyfluorinated alkyl substances (PFAS) in ambient air samples from Mace Head (Ireland) : A method intercomparison
- 2009
-
Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 43:4, s. 844-850
-
Tidskriftsartikel (refereegranskat)abstract
- A method intercomparison study of analytical methods for the determination of neutral, volatile polyfluorinated alkyl substances (PFAS) was carried out in March, 2006. Environmental air samples were collected in triplicate at the European background site Mace Head on the west coast of Ireland, a site dominated by 'clean' westerly winds coming across the Atlantic. Extraction and analysis were performed at two laboratories active in PFAS research using their in-house methods. Airborne polyfluorinated telomer alcohols (FTOHs), fluo ooctane sulfonamides and sulfonamidoethanols (FOSAs/FOSEs) as well as additional polyfluorinated compounds were investigated. Different native and isotope-labelled internal standards (IS) were applied at various Steps in the analytical procedure to evaluate the different quantification strategies. Field blanks revealed no major blank problems. European background concentrations observed at Mace Head were found to be in a similar range to Arctic data reported in the literature. Due to trace-levels at the remote site, only FTCH data sets were complete and could therefore be compared between the laboratories. Additionally, FOSEs Could Partly be included. Data comparison revealed that despite the challenges inherent in analysis of airborne PFAS and the low concentrations, all methods applied in this Study obtained similar results. However, application of isotope-labelled IS early in the analytical procedure leads to more precise results and is therefore recommended.
|
|
| 20. |
- Jahnke, Annika, et al.
(författare)
-
Reducing Uncertainty and Confronting Ignorance about the Possible Impacts of Weathering Plastic in the Marine Environment
- 2017
-
Ingår i: Environmental Science and Technology Letters. - : American Chemical Society (ACS). - 2328-8930. ; 4:3, s. 85-90
-
Forskningsöversikt (refereegranskat)abstract
- Plastic in the global oceans fulfills two of the three conditions for pollution to pose a planetary boundary threat because it is causing planetary-scale exposure that is not readily reversible. Plastic is a planetary boundary threat if it is having a currently unrecognized disruptive effect on a vital Earth system process. Discovering possible unknown effects is likely to be aided by achieving a fuller understanding of the environmental fate of plastic. Weathering of plastic generates microplastic, releases chemical additives, and likely also produces nanoplastic and chemical fragments cleaved from the polymer backbone. However, weathering of plastic in the marine environment is not well understood in terms of time scales for fragmentation and degradation, the evolution of particle morphology and properties, and hazards of the chemical mixture liberated by weathering. Biofilms that form and grow on plastic affect weathering, vertical transport, toxicity, and uptake of plastic by marine organisms and have been underinvestigated. Laboratory studies, monitoring, and models weathering on plastic debris are needed to reduce uncertainty in hazard and risk assessments for known and field of the impact of suspected adverse effects. However, scientists and decision makers must also recognize that plastic in the oceans may have unanticipated effects about which we are currently ignorant. Possible impacts that are currently unknown can be confronted by vigilant monitoring of plastic in the oceans and discovery-oriented research related to the possible effects of weathering plastic.
|
|
| 21. |
- Jahnke, Annika, et al.
(författare)
-
Sensitive equilibrium sampling to study polychlorinated biphenyl disposition in Baltic Sea sediment
- 2012
-
Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 46:18, s. 10114-10122
-
Tidskriftsartikel (refereegranskat)abstract
- An equilibrium sampling approach using glass jars with pm thin coatings of the silicone polydimethylsiloxane (PDMS) was validated and applied to background sediment samples from a >50 km transect in the Stockholm Archipelago. Equilibrium between the sediment and the PDMS was demonstrated using different coating thicknesses. From the concentrations of polychlorinated biphenyls (PCBs) in the PDMS, we assessed (i) freely dissolved concentrations in the sediment interstitial porewater (C-Sediment_free); (ii) the equilibrium brium status between sediment and water; (iii) the equilibrium status between sediment and biota; and (iv) site-specific sediment/water distribution ratios (K-D). The results showed that (i) Stockholm was a source of PCBs to the Baltic Sea as evidenced by significantly higher C-Sediment_free in Stockholm Harbor; (ii) the fugacity in sediment exceeded that in water (monitoring samples collected in February) by an average factor of 4.0; (iii) the fugacity in sediment exceeded that in herring by an average factor of 5.2; and (iv) K-D near Stockholm Harbor was 0.3-1.7 log units greater than in the outer archipelago. The coated glass jar method with its high precision and built-in QA/QC opens new possibilities to study the disposition of hydrophobic chemicals at trace levels (C-Sediment_free down to 1.06 fg/L) in background environments.
|
|
| 22. |
- Jahnke, Annika, et al.
(författare)
-
Silicone passive equilibrium samplers as 'chemometers' in eels and sediments of a Swedish lake
- 2014
-
Ingår i: Environmental Science Processes and Impacts. - : Royal Society of Chemistry (RSC). - 2050-7887 .- 2050-7895. ; 16:3, s. 464-472
-
Tidskriftsartikel (refereegranskat)abstract
- Passive equilibrium samplers deployed in two or more media of a system and allowed to come to equilibrium can be viewed as 'chemometers' that reflect the difference in chemical activities of contaminants between the media. We applied silicone-based equilibrium samplers to measure relative chemical activities of seven 'indicator' polychlorinated biphenyls (PCBs) and hexachlorobenzene in eels and sediments from a Swedish lake. Chemical concentrations in eels and sediments were also measured using exhaustive extraction methods. Lipid-normalized concentrations in eels were higher than organic carbon-normalized concentrations in sediments, with biota-sediment accumulation factors (BSAFs) of five PCBs ranging from 2.7 to 12.7. In contrast, chemical activities of the same pollutants inferred by passive sampling were 3.5 to 31.3 times tower in eels than in sediments. The apparent contradiction between BSAFs and activity ratios is consistent with the sorptive capacity of lipids exceeding that of sediment organic carbon from this ecosystem by up to 50-fold. Factors that may contribute to the elevated activity in sediments are discussed, including slower response of sediments than water to reduced emissions, sediment diagenesis and sorption to phytoplankton. The 'chemometer' approach has the potential to become a powerful tool to study the thermodynamic controls on persistent organic chemicals in the environment and should be extended to other environmental compartments.
|
|
| 23. |
- Jahnke, Annika, et al.
(författare)
-
Strategies for Transferring Mixtures of Organic Contaminants from Aquatic Environments into Bioassays
- 2016
-
Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 50:11, s. 5424-5431
-
Tidskriftsartikel (refereegranskat)abstract
- Mixtures of organic contaminants are ubiquitous ronment. Depending on their persistence and physicochemical properties, individual chemicals that make up the mixture partition and distribute within the environment and might then jointly elicit toxicological effects. For the assessment and monitoring of such mixtures, a variety of cell-based in vitro and low-complexity in vivo bioassays based on algae, daphnids or fish embryos are available. A very important and sometimes unrecognized challenge is how to combine sampling, extraction and dosing to transfer the mixtures from the environment into bioassays, while conserving (or re-establishing) their chemical composition at adjustable levels for concentration-effect assessment. This article outlines various strategies for quantifiable transfer from environmental samples including water, sediment, and biota into bioassays using total extraction or polymer-based passive sampling combined with either solvent spiking or passive dosing.
|
|
| 24. |
- Jahnke, Annika, et al.
(författare)
-
Trace analysis of per- and polyfluorinated alkyl substances in various matrices-how do current methods perform?
- 2009
-
Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1216:3, s. 410-21
-
Tidskriftsartikel (refereegranskat)abstract
- Per- and polyfluorinated alkyl substances (PFAS) are a group of industrial chemicals, some of which have been produced for over 50 years. Scarcely one decade ago, their ubiquity in wildlife, humans and the global environment was discovered. This urged the need for robust and reliable, yet very sensitive analytical methods allowing for their determination in various matrices. This article reviews the state-of-the-art in trace analysis of ionic and neutral PFAS in humans as well as environmental samples such as wildlife, water, solid matrices and air. Analytical protocols for PFAS determination in food and consumer products are also included. The methods are critically discussed in terms of their advantages, shortcomings, possibilities, limitations, and potential for further development.
|
|
| 25. |
|
|
