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Per- and polyfluorinated substances (PFASs) are a family of persistent organic pollutants in which the aliphatic carbon chains have been fluorinated, either completely or partially. One subclass of PFASs are perfluoroalkyl acids (PFAAs), in which perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) are two prominent groups. PFASs are toxic to the environment, as well as humans, and are found to have a developmental, neurological and immunological toxicity. They are also found to be possibly carcinogenic. In this study, the quantity of target PFASs was determined in 11 samples of hepatopancreas in crayfish from different locations in Lake Vättern, Sweden, using liquid chromatography coupled to tandem mass spectrometry. The hepatopancreas is the crayfish detoxification organ and therefore, it is also where persistent organic pollutants are possibly accumulated. Extractable organic fluorine concentration was also determined, using combustion ion chromatography to account for other fluorinated compounds not included in the target analysis of 31 PFASs. The amount of target PFASs was compared to the extractable organic fluorine concentration, giving an idea of how much of the extractable organic fluorine that consists of identified PFASs in relation to unidentified organic fluorine.  The measured concentrations of target PFASs were compared to measured concentrations in a previous study (2008) of PFASs in the hepatopancreas of crayfish from two different locations in Lake Vättern. Concentrations of the measured target PFASs were also related to if the sampling sites for each pooled sample was located close to a known point source, Karlsborg military airport. A sum of the average of PFHxS, PFOS, PFOA and PFNA for all sample sites were compared to a combined tolerable weekly intake (TWI) for these four compounds, established by the European Food Safety Authority (EFSA). As well as the intake of PFOS and PFOA compared individually against their TWI.

In this thesis a method of dry-ashing wood, sequential leaching of soil and analysis with ICP-QMS is tested as a possible way for establishing a correlation between bioavailable compounds in soil and uptake to birches. The total amount of trace elements (V, Sr, Cd, Pb and U) in stem wood and contaminated soils were analysed. The total concentration of metals in the soil was extracted using HCl and HNO3 in warm water bath. Biological availability of inorganic compounds in the soil were established using sequential leaching. The total concentration of metals in stem wood of birches were determined with the use of tree core samples, dry ashing and analysis with ICP-QMS. A rough estimation of each trees’ first 10 years through counting annual tree rings was also made, to be able to see when the tree accumulate most bioavailable elements. No correlation between the bioavailable concentration of elements in the soil and uptake to the birches could be found. Some deductions about where in the tree different elements appear could be done but more samples is needed to make a significant judgement.

Gullspångsälvens catchment area starts in the county of Dalarna and ends in the lake Vänern. On the way the water passes a couple of villages and small towns. The aim of the project is to identify point sources of PFAS and see their influence on the PFAS levels in the systems surface water. In the area some point sources have been identified. The villages and towns have waste water treatment plants and there are also a couple of landfills. Sampling have been carried out at expected point sources as well as in the surface water close to human activities. The samples have been extracted with SPE and analysed with LCMS-MS. Results show that the levels of PFAS is increasing through the system and that the expected point sources release PFAS to the environment. It was also possible to identify an earlier unknown point source. Compared with levels in other parts of Sweden (S-EPA, 2016) the levels of PFAS in the system is within a normal range except for the levels close to the until now unknown point source.

Perfluorooctane sulfonic acid (PFOS) has been regulated under Stockholm Convention in 2009, perfluorooctanoic acid (PFOA) was listed in 2019. Perfluorohexane sulfonic acid (PFHxS) is under review and could be included in 2021. There are still permitted uses of these three chemicals, but it is expected that the production and application will decrease as a result of the international regulation and the environmental concentrations of PFOS, PFOA and PFHxS are expected to decline. However, without a reference point, it is difficult to judge if the levels are decreasing or not. Therefore, baseline levels of PFOS, PFOA and PFHxS in one of United Nations Environment Programme (UNEP) core matrices, surface water, were established with the support of samples collected from Africa (n=34), Asia (n=11), Group of Latin America and Caribbean (GRULAC) (n=35) and Pacific Islands (n=25) under a period of two years. The baseline levels were set as the median concentration (ng/L) in each region (interquartile range) based on a variance test (Kruskal-Wallis) and descriptive statistical testing. Baseline levels for ΣPFOS, PFOA and PFHxS including all countries in Africa (n=6) was set at 0.38 (0.18 – 0.54) ng/L, 0.26 (0.13 – 0.80) ng/L and 0.042 (0.02 - 0.09) ng/L respectively, and excluding Kenya and Tunisia (n=4) at 0.22 (0.10 – 0.38) ng/L for ΣPFOS , 0.18 (0.10 – 0.25) ng/L for PFOA and 0.031 (0.02 – 0.04) ng/L for PFHxS. In Pacific Islands the baseline levels for ΣPFOS, PFOA and PFHxS were established at 0.15 (0.04 – 1.24) ng/L, 0.046 (0.03 – 0.11) ng/L and 0.055 (0.01 – 0.63) ng/L including all countries (n=7), and 0.053 (0.03 – 0.15) ng/L, 0.033 (0.03 – 0.04) ng/L and 0.012 (0.01 – 0.05) ng/L excluding Vanuatu and Kiribati (n=5). In Asia and Group of Latin America samples were in similar concentrations range within the region, so baseline levels for ΣPFOS, PFOA and PFHxS in Asia were set at 0.048 (0.04 - 0.12) ng/L, 0.11 (0.07 – 0.19) ng/L and 0.018 (0.01-0.03) ng/L, and in GRULAC at 1.31(0.39 – 1.88) ng/L, 0.50 (0.28 – 0.71) ng/L and 0.14 (0.06 – 0.44) ng/L for the three priority PFASs respectively. The importance of the three PFASs in relation to other measured Σ73 PFASs were assessed in selected samples (n=12) including six samples from Sweden. The results showed a contribution of 10% to 48% of the sum of the three priority PFASs to all 27 detected PFASs.It is not clear whether a total of 73 PFASs is enough to explain the environmental contamination of PFASs and therefore the extractable organofluorine (EOF) was measured in selected samples (n=12). Due to the high EOF levels in procedural blanks, only two out of twelve samples were used to assess the contribution of detected PFASs to EOF. The contribution of 27 detected PFASs to EOF were 3% for Vanuatu and 5% for Sweden (Svartån). The contribution of the sum of the three PFASs to EOF accounted for 1.1% for Vanuatu and 1.4% for Svartån. Nevertheless, within the organofluorine fraction, a major percentage 95% to 97% of fluorine remains unknown in water samples, suggesting the occurrence of other organofluorine substances. At the same time, some newly identified PFAS (novel PFASs) that are known to replace PFOS and PFOA in different applications were detected in surface water samples collected from Sweden (n=6) and from developing countries under UNEP/GMP2 project (n=6). Perfluoroethylcyclohexane sulfonate (PFECHS) was detected in four samples in concentrations ranging between 0.03 and 0.14 ng/L. Perfluoro-2-propoxypropanoic acid (HFPO-DA) was detected in three samples in the concentration range 0.03-0.06 ng/L.

Temporal and spatial variations of microlitter (ML) concentrations in Gothenburg were measured by sampling surface water. ML was divided into three main categories; microplastics (MP), fibers (F) and other anthropogenic particles (OA). Samples were collected using a pump installed with 300 μm and 50 μm stainless mesh filters, during three separate field sampling campaigns during the fall and early winter of 2017. Samples were treated with H2O2 digestion for removing organic material. Microlitter were then visually counted and categorized for all samples under light microscope. In the 300 μm fraction, F was most prevalent at 84.6 %, MP at 12.9 % and OA at 2.5 %. Concentrations of MP varied from 0.1 to 22 MP/m3 in the 300 μm size fraction and from 0 to 81 MP/m3 in the 50 μm size fraction. MP concentrations collected on the 50 μm size filter were higher compared to the 300 μm size filter in all but two samples. MP from the 300 μm size fraction was further subcategorized as particle/fragment (71 %), film (14 %), filament (9 %), expanded cellstructure (3 %) and pellets (3 %). MP concentrations found in Gothenburg surface water are comparable to what has been found in other urban cities of Sweden, but higher compared to studies measuring MP concentrations along the Swedish east, west and southern coastline. The polymeric structure of MP particles from the 300 μm size fraction was analyzed with Attenuated Total Reflection Fourier Transform IR (ATR-FTIR) and were identified as polyethylene (46.5 %), polypropylene (17.2 %), polystyrene (9.0 %), polyethylene terephthalate (3.1 %), polyamide (1.2 %), and 23 % were unmatched. Possible correlating factors such as precipitation and ML concentrations were explored but the data was insufficient for any decisive conclusions to be made. Flow rate, the volume of water passing per time unit in the water course was shown to have an inverse correlation with concentration. Large temporal variation was observed at most of the sampling sites. It is not possible to pin point or quantify any particular source of ML pollution with this data, however it can be stated that ML’s from various urban sources indeed do contribute to ML pollution, and that the pollution from these sources vary over time based on factors that are not yet known.

Dissolved organic matter (DOM) is the prevalent form of organic carbon in most aquatic environments. It is an ultra-complex mixture that plays a crucial role in global carbon cycling. Despite its importance it is still poorly understood due to its extreme heterogeneity and intricacy. Major advances in chemical characterization of DOM were possible with the introduction of high-resolution mass spectrometry (HRMS). This technique, in combination with direct infusion (DI) as sample introduction, is the most powerful tool for the DOM analysis to date. A compelling alternative to DI is represented by upfront separation with liquid chromatography (LC); however, current techniques involve only offline LC-HRMS approaches, which exhibit important logistical drawbacks, making DOM analysis more challenging. The aim of the presented studies was to develop new methods able to enhance the analysis of the dissolved organic matter and enable a wider range of researchers to participate in the advancement of this field. In the first study, the application of the Orbitrap mass spectrometer for resolving complex DOM mixtures was investigated and the results were compared to the more established state-of-the-art technique, Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The Orbitrap was capable of excellent reproducibility and detection of the majority of ionizable organic molecules in typical aquatic mixtures. The main disadvantage of the technique is that fewer molecular formulas can be resolved and detected because of lower resolution and sensitivity. This means that many sulfur peaks and all phosphorous containing peaks are not determined. Despite this drawback, our results suggest that the Orbitrap is an appropriate technique for the investigation of very subtle biogeochemical processing of bulk DOM. The lower costs (purchase and maintenance) and wider availability of Orbitrap mass spectrometers allow a greater number of laboratories to participate in the characterization of DOM. In the second study, the first online method involving reverse phase chromatography and ultrahigh resolution mass spectrometry for the analysis of DOM was developed. This method overcomes the disadvantages of typical offline approaches. It enhances enormously the amount of information achievable in a single run, maintaining high resolution data, reducing analysis time and potential contamination. The introduction of in silico fractionation makes the method extremely flexible, allowing an easy, fast, and detailed comparison of DOM samples from a variety of sources.

Total oxidizable precursor (TOP) assay is an in-lab method which oxidatively converts precursor compounds of poly- and perfluoroalkyl substances (PFASs) into measurable perfluorinated alkyl acids (PFAAs). The method is a very strong tool to semi-quantify PFASs that would otherwise be missed in conventional targeted analysis using liquid chromatography - tandem mass spectrometry (LC-MS/MS). However, there are still challenges for it to be a fully quantitative tool. This report aims to increase the knowledge in using measures to improve the quality assurance of the assay, as well as investigate potential limitations of applying TOP assay outside the scope of what it was originally developed for. Furthermore, the objective was also to apply an evaluated TOP assay method on sample extracts from influent and effluent water from wastewater treatment plants (WWTPs) in China to investigate the occurrence of both legacy and novel PFASs. To achieve improved quality assurance of the method, the use of isotopically labelled standards in the TOP assay were investigated. 13C8-FOSA was used as a model compound to measure the oxidation efficiency in the assay; the results showed that the molar yield of 13C8-FOSA to 13C8-PFOA was 99% ± 2% (n=12) for the WWTP samples. This indicated it to be a good tool to monitor the oxidation, but more research is needed to understand the fate and reaction rate of other precursors. Oxidation of sample extracts were performed without evaporating solvent before oxidation to minimize loss of volatile precursors. This procedure was shown to be possible but require additional oxidation agent and base and may lead to different product pattern after oxidation. Further, performing TOP assay on sample extracts will introduce bias in which types of precursors are extracted and may lead to an underestimation of total PFAAs precursor present, depending on the extraction method or solvent type used. Additionally, the stability of two novel compound groups in the assay were investigated: 1) The Pre 2002 and Post 2002 formulas of Scotchgard™ fluorinated side-chain polymers were both degraded in the assay. For the Pre 2002 formula the primary degradation product was PFOA and for the Post 2002 formula, PFBA was the degradation product. Additionally, both the Pre 2002 and Post 2002 formulas were shown to undergo hydrolysis in high pH conditions, producing perfluoroalkyl sulfonic acids (PFSAs). 2) Per- and polyfluorinated ether acids (PFEAs) were also investigated in the TOP assay, which indicated that perfluorinated ether acids are stable in high pH oxidative conditions but may degrade in low pH oxidative conditions, while polyfluorinated ether acids may be degraded under oxidative conditions in both high and low pH. The analysis of influent and effluent water from Chinese WWTPs was done by screening for 14 legacy PFASs, 16 novel PFASs, and performing TOP assay on sample extracts as well as analysis of extractable organic fluorine for mass balance analysis. Perfluorobutanoic acids (PFBA) had the highest detection rate among the legacy PFASs, and hexafluoropropylene oxide dimer acid (HFPO-DA) was the most prevalent novel PFASs detected. TOP assay on the anionic fraction lead to varying degree increase in PFAS concentration (0-15x) while performing the oxidation on the neutral/cationic fraction did not lead to any observable increase in PFASs. Even with TOP assay, the proportion of extractable organic fluorine still unidentified was 11% to 98%.

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