| 1. |
- Mashayekhy Rad, Farshid, 1973-
(author)
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Analytical methods for biomolecules involved in atmospheric aerosol formation in the Arctic
- 2018
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Doctoral thesis (other academic/artistic)abstract
- In the Arctic, increasing ice-free conditions and nutrients freed from the melting ice must strongly influence the marine life. Aerosol emissions from microbiological marine processes may affect the low clouds and fogs over the summer Arctic, which in turn have effects on the melting of sea ice. The radiative properties of the high Arctic low clouds are strongly dependent on the number concentration of airborne water-soluble particles, known as cloud condensation nuclei (CCN). If the effects of CCN on cloud optical properties is to be fully understood it is important to be able to specify the source and concentrations of the Arctic aerosol particles.Previous studies in the Arctic have indicated that organic material formed in the uppermost ocean surface is transferred to the atmosphere and plays a potentially very important role in the aerosol-fog/cloud cycle. However, many aspects of this process remain unverified and chemical characterisation of targeted groups of biomolecules is still notably fragmentary or non-existing. Investigation of biomolecules, particularly amino acids, peptides and proteins together with mono- and polysaccharides and fatty acids in the airborne aerosol, and their relative contributions to fog/cloud water, requires development of an array of “cutting edge” analytical techniques and methods.In this thesis, electrospray ionization mass spectrometry was used for all applications and target biomolecules. The measurements in the Arctic turned out to be challenging due to the highly complex, salty matrices, combined with very low concentration and high diversity of the target biomolecules, and each step of the analytical chain needed careful consideration. To increase the detectability of the very low levels of polysaccharides and proteins in aerosols, these compounds were hydrolyzed to their subunits, monosaccharides and amino acids. Monosaccharides were separated using hydrophilic interaction chromatography, which was beneficial for their detection in electrospray ionization mass spectrometry. Amino acids were derivatized, yielding improvement in reversed-phase chromatographic separation, ionization efficiency as well as selectivity. For fatty acids in a sea surface sample, a novel fast screening method was developed, utilizing travelling-wave ion mobility separation as an orthogonal technique connected to mass spectrometry. In addition, a method for the detection of wood burning as an anthropogenic source of aerosols was developed, utilizing anhydrous monosaccharides as markers. This method can be used in the upcoming expeditions for source apportionment studies.The results from the analyses of the aerosol and fog water samples, collected over the summer pack ice north of 80 °N, show that both total polysaccharides and total proteinaceous compounds (sum of proteins, peptides and amino acids) occurred at the pmol m-3 to nmol m-3 level. Interestingly, the levels were found higher between different years, suggested to be coupled to less ice coverage and thus to a higher biological activity in the ocean surface. The highest concentrations of polysaccharides, as an indication of marine polymer gels, were found during the summer over the pack ice area. In addition, a pilot source apportionment study was carried out combining the measurement of different molecular tracers, used as source markers. This study indicates the seasonality and abundance of marine polymer gels as an important feature of the Arctic Ocean connected to the melting and freezing of sea ice. It should be further studied how the abundance of these gels, which have a high potential for cloud droplet activation, affect the melting and freezing of the perennial sea ice.Given the successful development of analytical methods for targeted groups of biomolecules, this thesis has supported the importance of biomolecules as CCN and for cloud formation in the Arctic. Less ice coverage may further increase the number of biomolecular CCN which could change the radiative balance, by the formation of more low-level clouds. Overall, more studies are required to further unravel the complex relationship of biogenic sources, atmospheric chemistry and meteorology to assess the impact of climate change on the Arctic.
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| 2. |
- Blum, Kristin, 1989-
(author)
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Targeted and untargeted analysis of organic contaminants from on-site sewage treatment facilities : Removal, fate and environmental impact
- 2018
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Doctoral thesis (other academic/artistic)abstract
- On-site sewage treatment facilities (OSSFs) are widely used all over the world to treat wastewater when large-scale sewage treatment plants (STPs) are not economically feasible. Although there is great awareness that the release of untreated wastewater into the environment can lead to water-related diseases and eutrophication, little is known about organic contaminants and their removal by OSSFs, environmental load and fate. Thus, this PhD thesis aims to improve the knowledge about treatment efficiencies in current OSSFs, the environmental impact and fate of contaminants released from OSSFs, as well as how biochar fortification in sand filter (soil beds) OSSFs might increase removal of these contaminants. State-of-the-art analytical techniques for untargeted and targeted analyses were used and the results evaluated with univariate and multivariate statistics.Environmentally-relevant contaminants discharged from OSSFs were identified using untargeted analysis with two-dimensional gas chromatography mass spectrometry (GC×GC-MS) and a MS (NIST) library search in combination with a prioritization strategy based on environmental relevance. A method was successfully developed for the prioritized contaminants using solid phase extraction and GC×GC-MS, and the method was also applicable to untargeted analysis. This method was applied to several studies. The first study compared treatment efficiencies between STP and soil beds and showed that treatment efficiencies are similar or better in soil beds, but the removal among the same type of treatment facilities and contaminants varied considerably. Hydrophilic contaminants were generally inadequately removed in both types of treatment facilities and resulted in effluent levels in the nanogram per liter range.Additionally, several prioritized and sometimes badly removed compounds were found to be persistent, mobile, and bioavailable and two additional, untargeted contaminants identified by the NIST library search were potentially mobile. These contaminants were also found far from the main source, a large-scale STP, at Lake Ekoln, which is part of the drinking water reservoir Lake Mälaren, Sweden. The study also showed that two persistent, mobile and bioavailable contaminants were additionally bioaccumulating in perch. Sampling for this study was carried out over several seasons in the catchment of the River Fyris. Parts of this catchment were affected by OSSFs, other parts by STPs. Potential ecotoxicological risks at these sites were similar or higher at those affected by STPs compared to those affected by OSSFs. Mass fluxes per capita were calculated from these levels, which were higher at STP-affected than at OSSF-affected sites in summer and autumn, but not in winter. Possibly, the diffuse OSSF emissions occur at greater average distances from the sampling sites than the STP point emissions, and OSSF-affected sites may consequently be more influenced by fate processes.The studies carried out suggested that there is a need to improve current treatment technologies for the removal of hydrophilic contaminants. Thus, the final study of this thesis investigated char-fortified sand filters (soil beds) as potential upgrades for OSSFs using a combination of advanced chemical analysis and quantitative structure-property relationship modeling. Removal efficiencies were calculated from a large variety of contaminants that were identified by untargeted analysis using GC×GC-MS and liquid chromatography ion mobility mass spectrometry as well as library searches (NIST and Agilent libraries). On average, char-fortified sand filters removed contaminants better than sand, partly due to an enhanced removal of several hydrophilic contaminants with heteroatoms. After a two-year runtime, sorption and particularly biodegradation must have contributed to the removal of these compounds.Generally, the combination of targeted and untargeted analysis has proven valuable in detecting a large variety of organic contaminants, as well as unexpected ones. The results imply that OSSFs have similar or better removal efficiencies, similar or lower environmental risks and similar or lower mass fluxes per capita, compared to STPs. Biochar fortification can improve the removal of organic contaminants in soil beds, but further research is needed to find technologies that reduce the discharge of all types of organic contaminants.
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| 3. |
- Iadaresta, Francesco, 1985-
(author)
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Textile Related Chemicals: Analytical Approaches Towards the Assessment of Human and Environmental Exposures
- 2019
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Doctoral thesis (other academic/artistic)abstract
- The textile manufacturing chain involves an extensive use of chemicals as early as fabric-production. To confer special features to textile materials, more chemicals are required in subsequent steps. Furthermore, potentially harmful substances can end up in clothes as transformation products. Compounds that are not covalently bonded to the fabrics have high probability to be released on the skin or into the environment when the clothes are worn or laundered.In order to remove interfering compounds from solvent extracts of investigated textiles, a cleanup step based on solid phase extraction using graphitic carbon black was developed resulting in effective dye removal. In a pilot screening, nitroanilines were detected up to 0.57 mg/g, which was 2-3 order of magnitude higher than measured quinolines.Human exposure to chemicals can occur through skin contact. Benzothiazole was chosen as model compound for in-vitro experiments. Its permeation was experimentally determined in order to estimate dermal exposure. Carcinogenic and non-carcinogenic risks, associated to wearing t-shirt containing BT, according to international standards, were found to be below the acceptable exposure levels.It has been shown that chemical concentrations decreased during domestic washing. A procedure was developed for enrichment and clean-up of textile related compounds from water samples. The method was applied to three wastewater treatment plant effluents located in Stockholm. Tolyltriazole, 1-benzotriazole, and UV-P were detected within the range of 53-1148 ng/L.Suspect and non-target screening methodology was developed do detect and identify substances in textile materials. The occurrence of thirteen suspect compounds, belonging to quinolines, nitroanilines, benzotriazoles, benzothiazoles and phthalates, was confirmed through suspect analysis approach. Furthermore, using a non-target screening approach, compounds not included in the suspect list such as nitrophenols, organophosphate and acridine were identified.In order to remove interfering compounds from the textile extracts, a cleanup step based on solid phase extraction using graphitic carbon black was developed resulting in effective dye removal. In a pilot screening, nitroanilines were detected up to 0.57 mg/g, which was 2-3 times higher than measured quinolines.Human exposure to chemicals can occur through skin contact. Benzothiazole was chosen as model compound for in-vitro experiments. Its permeation was experimentally determined in order to estimate dermal exposure. Carcinogenic and non-carcinogenic risks, associated to wearing t-shirt containing BT, according to international standards, were found to be below the acceptable exposure levels.It has been shown that chemical concentrations decreased during domestic washing. A procedure was developed for enrichment and clean-up of textile related compounds from water samples. The method was applied to three wastewater treatment plant effluents located in Stockholm. Tolyltriazole, 1-benzotriazole, and UV-P were detected within the range of 53-1148 ng/L. Suspect and non-target screening methodology was developed do detect and identify substances in textile materials. The occurrence of thirteen suspect compounds, belonging to quinolines, nitroanilines, benzotriazoles, benzothiazoles and phthalates, was confirmed through suspect approach. Furthermore, using a non-target screening approach, compounds not included in suspect list such as nitrophenols, organophosphate and acridine were identified.
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| 4. |
- Jonsson, Sofia, 1973-
(author)
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The influence of soil and contaminant properties on the efficiency of physical and chemical soil remediation methods
- 2009
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Doctoral thesis (other academic/artistic)abstract
- A vast number of sites that have been contaminated by industrial activities have been identified worldwide. Many such sites now pose serious risks to humans and the environment. Given the large number of contaminated sites there is a great need for efficient, cost-effective remediation methods. Extensive research has therefore been focused on the development of such methods. However, the remediation of old industrial sites is challenging, for several reasons. One major problem is that organic contaminants become increasingly strongly sequestered as they persist in the soil matrix for a long period of time. This process is often referred to as ‘aging’, and leads to decreasing availability of the contaminants, which also affects the remediation efficiency. In the work underlying this thesis, the influence of soil and contaminant properties on the efficiency of various physical and chemical soil remediation methods was investigated. The investigated contaminants were polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Briefly, the results show that as the size of soil particles decreases the contaminants become more strongly sorbed to the soil’s matrix, probably due to the accompanying increases in specific surface area. This affected the efficiency of the removal of organic pollutants by both a process based on solvent washing and processes based on chemical oxidation. The sorption strength is also affected by the hydrophobicity of the contaminants. However, for a number of the investigated PAHs their chemical reactivity was found to be of greater importance for the degradation efficiency. Further, the organic content of a soil is often regarded as the most important soil parameter for adsorption of hydrophobic compounds. In these studies the effect of this parameter was found to be particularly pronounced for the oxidation of low molecular weight PAHs, but larger PAHs were strongly adsorbed even at low levels of organic matter. However, for these PAHs the degradation efficiency was positively correlated to the amount of degraded organic matter, probably due to the organic matter being oxidized to smaller and less hydrophobic forms. The amount of organic matter in the soil had little effect on the removal efficiency obtained by the solvent-washing process. However, it had strong influence on the performance of a subsequent, granular activated carbon-based post-treatment of the washing liquid. In conclusion, the results in this thesis show that remediation of contaminated soils is a complex process, the efficiency of which will be affected by the soil matrix as well as the properties of the contaminants present at the site. However, by acquiring thorough knowledge of the parameters affecting the treatability of a soil it is possible to select appropriate remediation methods, and optimize them in terms of both remediation efficiency and costs for site- and contaminant-specific applications.
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| 5. |
- Larsson, Maria, 1975-
(author)
-
Chemical and bioanalytical characterisation of PAH-contaminated soils : identification, availability and mixture toxicity of AhR agonists
- 2013
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Doctoral thesis (other academic/artistic)abstract
- Contaminated soils are a worldwide problem. Polycyclic aromatic hydrocarbons (PAHs) are common contaminants in soil at former industrial areas, especially at old gasworks sites, gas stations and former wood impregnation facilities. Risk assessments of PAHs in contaminated soils are usually based on chemical analysis of a small number of individual PAHs, which only constitute a small part of the complex cocktail of hundreds of PAHs and other related polycyclic aromatic compounds (PACs) in the soils. Generally, the mixture composition of PAH-contaminated soils is rarely known and the mechanisms of toxicity and interactions between the pollutants are far from fully understood.The main objective of this thesis was to characterize remediated PAHcontaminated soils by use of a chemical and bioanalytical approach. Bioassay specific relative potency (REP) values for 38 PAHs and related PACs were developed in the sensitive H4IIE-luc bioassay and used in massbalance analysis of remediated PAH contaminated soils, to assess the contribution of chemically quantified compounds to the overall aryl hydrocarbon receptor (AhR)-mediated activity observed in the H4IIE-luc bioassay. Mixtures studies showed additive AhR-mediated effects of PACs, including PAHs, oxy PAHs, methylated PAHs and azaarenes, in the bioassay, which supports the use of REP values in risk assessment. The results from the chemical and bioassay analysis showed that PAH-contaminated soils contained a large fraction of AhR activating compounds whose effect could not be explained by chemical analysis of the 16 priority PAHs. Further chemical identification and biological studies are necessary to determine whether these unknown substances pose a risk to human health or the environment. Results presented in this thesis are an important step in the development of AhR-based bioassay analysis and risk assessment of complex PAH-contaminated samples.
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| 6. |
- Rattfelt Nyholm, Jenny, 1975-
(author)
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Persistency, bioaccumulation and toxicity assessment of selected brominated flame retardants
- 2009
-
Doctoral thesis (other academic/artistic)abstract
- Brominated flame retardants (BFRs) are chemicals used in e.g. electronic equipment, textiles and plastics for the prevention of fire. Over recent decades, concern has been raised regarding some heavily used BFRs, since the levels in the environment have been increasing. In the present thesis, persistent, bioaccumulative, and toxic (PBT) properties were studied for a structurally varied set of BFRs selected to represent more than 60 organic BFRs. The studied BFRs include: 2,4,4'-tribromodiphenyl ether (BDE 28), 2,2',3,4,4',5',6-heptabromodiphenyl ether (BDE 183), decabromodiphenyl ether (BDE 209), hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBPA), tetrabromobisphenol A 2-hydroxyethyl ether (TBBPA OHEE), 2,4,6-tribromophenol (246BrPh), 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH), and hexabromobenzene (HxBrBz).It is likely that soil will act as a sink for BFRs. Therefore, studies of BFRs were performed on persistence in soil, and on bioaccumulation from soil in the earthworm Eisenia fetida. Large variation in the biodegradability in soil among the tested BFRs was observed. The studied brominated diphenyl ethers (BDE 28 and BDE 209) were very persistent under both aerobic and anaerobic conditions, while 246BrPh and TBECH degraded quickly in both aerobic and anaerobic soil. The bioaccumulation in earthworm from soil was high for HxBrBz, TBECH and for tested brominated diphenyl ethers with 4-6 bromine atoms (BDE 47, BDE 99, and BDE 153). Bioaccumulation was also studied in zebrafish after dietary exposure to a mixture of BFRs. It was shown that several metabolites were formed and retained in zebrafish, which highlights the importance of also searching for and identifying persistent degradation products. Maternal transfer was shown for all BFRs present in the female zebrafish. This shows that zebrafish young (fry) are exposed to these BFRs at approximately the same concentrations as female zebrafish during the early-life stages, when fish are usually most sensitive to organic contaminants. Toxicity of individual BFRs and a BFR mixture was studied in Nitocra spinipes using a silica gel-based system. Highest toxicities were observed for BDE 28, TBBPA, and TBBPA OHEE. In the mixture toxicity study, simultaneous exposure to low concentrations (individually causing no significant effect) of six BFRs significantly affected the survival of Nitocra spinipes. The results from the PBT studies presented in the thesis and literature data were compared with the criteria for PBT classification, as set in the European REACH legislation. Further, some BFRs with physico-chemical properties similar to those of identified PBTs were suggested to be prioritized for future PBT testing.
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| 7. |
- Rebryk, Andriy, 1989-
(author)
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Comprehensive non-target screening to find and identify new biomagnifying organic contaminants in Baltic Sea top consumers
- 2022
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Doctoral thesis (other academic/artistic)abstract
- The development of industrial processes in the 19th and 20th centuries, in particular oil refining, resulted in a huge discovery and subsequent large-scale production of a variety of chemicals. These useful chemicals supposedly made the everyday lives of people easier and better by, for instance, controlling the spread of diseases such as malaria, through the use of DDT and other organochlorine pesticides (OCPs).During the 1970s and following decades, it was hypothesized and later shown, that these, and other “helpful chemicals” such as polychlorinated biphenyls (PCBs), played a crucial role in the steep population decline observed for multiple species in the Baltic Sea. They were classified as anthropogenic (man-made) hazardous substances (AHSs). Many AHSs can be stored in fatty tissues of the organisms and magnify in species at high trophic levels (predators) of the food web, as a result of persistence and transfer from lower-level organisms (prey). This process is called biomagnification and is characterized by biomagnification or trophic magnification factors (BMFs or TMFs, respectively). AHSs can be roughly divided into known chemicals of concern, such as persistent organic pollutants (POPs), and contaminants of emerging concern (CECs), that include novel flame retardants, polymer additives, and many more. Both the production and use of a number of AHSs have been regulated since the 1970s. To understand the outcome of the regulations, retrospective analysis of samples from different years, a time-trend study, is often utilized.The main aim of this work was to develop a non-selective sample extraction, purification, and analysis method, and then find and identify as many biomagnifying contaminants as possible. To assess both biomagnification and temporal trends of a wide range of chemical contaminants in a given Baltic Sea food web, non-target screening (NTS) was used. A clean-up method was established and tested with a satisfactory outcome: processed extracts were pure enough for gas chromatography-mass spectrometry (GC-MS) analysis. Also, accompanying NTS data processing workflows were developed. Application of these resulted in BMFs for more than 100 contaminants (Paper I). The data processing workflow was refined for faster detection of chemicals that demonstrate temporal trends and/or biomagnify. It was possible to detect and tentatively identify more than 300 legacy POPs and CECs with statistically significant temporal trends in three Baltic top consumers (Paper II). Adjusted NTS workflows were used to reveal more than 250 compounds that possessed trophic magnification properties (Paper III). Inspired by the discovery of a novel flame retardant Dechlorane 602 (Paper I), a suspect screening for dechlorane-related compounds and their transformation products was carried out. A total of 31 compounds were detected and tentatively identified, many of which showed significant temporal trends and biomagnification (Paper IV). A number of compounds reported in Papers I–IV were tentatively identified for the first time in wildlife. In addition, the papers provide valuable spectral and retention information for the researchers in the field.In conclusion, this thesis presents useful GC-MS-based NTS workflows and biomagnification or time-trend data for a plethora of organic contaminants in the Baltic Sea food web. The data can contribute to i) the assessment of the influence pollutants have on the ecosystem and ii) various mitigation actions for AHSs, such as evaluating dechloranes for regulation under the Stockholm Convention on POPs, helping in the fight for a better environment and future.
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| 8. |
- Arnoldsson, Kristina, 1961-
(author)
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Polybrominated dibenzo-p-dioxins : Natural formation mechanisms and biota retention, maternal transfer, and effects
- 2012
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Doctoral thesis (other academic/artistic)abstract
- Polybrominated dibenzo-p-dioxins (PBDD) and dibenzofurans (PBDF) are a group of compounds of emerging interest as potential environmental stressors. Their structures as well as toxic responses are similar to the highly characterized toxicants polychlorinated dibenzo-p-dioxins. High levels of PBDDs have been found in algae, shellfish, and fish, also from remote areas in theBaltic Sea. This thesis presents studies on PBDD behavior in fish and offspring, and natural formation of PBDDs from naturally abundant phenolic precursors.The uptake, elimination, and maternal transfer of mono- to tetraBDD/Fs were investigated in an exposure study reported in Paper I. The effects of PBDDs in fish were examined in a dose-response study (Paper II). It was shown that fish can assimilate PBDD/Fs from their feed, although non-laterally substituted congeners were rapidly eliminated. Laterally substituted congeners were retained as was congeners without vicinal hydrogens to some extent. PBDD/Fs were transferred to eggs, and congeners that were rapidly eliminated in fish showed a higher transfer ratio to eggs. Exposure to the laterally substituted 2,3,7,8-TeBDD had significant effects on the health, gene expression and several reproduction end-points of zebrafish, even at the lowest dose applied.The geographical and temporal variations of PBDD in biota samples from the Baltic Seasuggest biogenic rather than anthropogenic origin. In Paper III, bromoperoxidase-mediated coupling of 2,4,6-tribromophenol yielded several PBDD congeners, some formed after rearrangement. The overall yield was low, but significantly higher at low temperature, and the product profile obtained was similar to congener profiles found in biota from the Swedish West Coast. In Paper IV, photochemically induced cyclization of hydroxylated polybrominated diphenyl ethers under natural conditions produced PBDDs at percentage yield. Rearranged products were not detected, and some abundant congeners do not seem to be formed this way. However, the product profile obtained was similar to congener profiles found in biota from the Baltic Proper.Since the PBDD congeners found in biota have a high turn-over in fish, the exposure must be high and continuous to yield the PBDD levels measured in wild fish. Thus, PBDDs must presumably be formed by common precursors in general processes, such as via enzymatic oxidations, UV-initiated reactions or a combination of both. The presented pathways for formation of PBDDs are both likely sensitive to changes in climatic conditions.
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| 9. |
- Bjurlid, Filip, 1978-
(author)
-
Polybrominated dibenzo-p-dioxins and furans : from source of emission to human exposure
- 2018
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Doctoral thesis (other academic/artistic)abstract
- Brominated flame retardants (BFRs), which are ubiquitous in modern life and the environment, are the major source for polybrominated dibenzo-p-dioxins and furans (PBDD/Fs). The knowledge about PBDD/Fs is lim-ited compared to other environmental pollutants, even though PBDD/Fs show similar toxicity as polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) which are considered to be among the most toxic man-made substances. The aim of the thesis was to provide a better understanding of PBDD/Fs by investigating the occurrence and distribution of PBDD/Fs in the following matrices: soot and gas from an accidental fire site which is a typical source of emission, blubber from marine mammals living in both far remote areas as well as areas close to anthropogenic sources, and finally in human milk from ten nursing mothers.PBDD/Fs was detected in blubber from pilot whales sampled around Faroe Islands, which proved the occurrence in marine mammals in a far remote area. The findings of PBDD/Fs in blubber from Baltic ringed seals showed slightly higher concentrations compared to the pilot whales, which is expected since the Baltic Sea in among the world’s most contam-inated water areas. In the pilot whales and the ringed seals, the average contribution from PBDD/Fs to the total (PCDD/F+PBDD/F) Total Equiv-alent Quantity (TEQ) was low, (1-8%). In gas and soot samples from the accidental fire site, PBDD/Fs were detected in all samples and the contri-bution of PBDD/Fs to the total TEQ was close to 100%. In the human milk samples, PBDD/Fs were detected in all samples and the average con-tribution of PBDD/Fs to the total TEQ was 40%. The results indicate that PBDD/Fs are of concern for human exposure, and should be monitored together with PCDD/Fs in future studies. Moreover, the occurrence at ac-cidental fire sites indicate that PBDD/Fs are a source for occupational ex-posure for firefighters and other professionals. The impact from PBDD/Fs on marine mammalians seems to be of less concern.
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| 10. |
- Do, Lan, 1985-
(author)
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New tools for sample preparation and instrumental analysis of dioxins in environmental samples
- 2013
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Doctoral thesis (other academic/artistic)abstract
- Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), two groups of structurally related chlorinated aromatic hydrocarbons, are of high concern due to their global distribution and extreme toxicity. Since they occur at very low levels, their analysis is complex, challenging and hence there is a need for efficient, reliable and rapid alternative analytical methods. Developing such methods was the aim of the project this thesis is based upon.During the first years of the project the focus was on the first parts of the analytical chain (extraction and clean-up). A selective pressurized liquid extraction (SPLE) procedure was developed, involving in-cell clean-up to remove bulk co-extracted matrix components from sample extracts. It was further streamlined by employing a modular pressurized liquid extraction (M-PLE) system, which simultaneously extracts, cleans up and isolates planar PCDD/Fs in a single step. Both methods were validated using a wide range of soil, sediment and sludge reference materials. Using dichloromethane/n-heptane (DCM/Hp; 1/1, v/v) as a solvent, results statistically equivalent to or higher than the reference values were obtained, while an alternative, less harmful non-chlorinated solvent mixture - diethyl ether/n-heptane (DEE/Hp; 1/2, v/v) – yielded data equivalent to those values.Later, the focus of the work shifted to the final instrumental analysis. Six gas chromatography (GC) phases were evaluated with respect to their chromatographic separation of not just the 17 most toxic congeners (2,3,7,8-substituted PCDD/Fs), but all 136 tetra- to octaCDD/Fs. Three novel ionic liquid columns performed much better than previously tested commercially available columns. Supelco SLB-IL61 offered the best overall performance, successfully resolving 106 out of the 136 compounds, and 16 out of the 17 2,3,7,8-substituted PCDD/Fs. Another ionic liquid (SLB-IL111) column provided complementary separation. Together, the two columns separated 128 congeners. The work also included characterization of 22 GC columns’ selectivity and solute-stationary phase interactions. The selectivities were mapped using Principal Component Analysis (PCA) of all 136 PCDD/F’s retention times on the columns, while the interactions were probed by analyzing both the retention times and the substances’ physicochemical properties.
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