Diss. (sammanfattning) Uppsala : Uppsala universitet, 2006. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2006. / Härtill 3 uppsatser.

Contaminated soils and sediments have been identified as significant secondary sources of organic contaminants.  Leaching tests may be useful tools to estimate the mobility of contaminants via the water phase and thereby the risk for groundwater and surface water contamination. The influence of soil composition (peat and clay content) on the leachability was investigated in batch leaching experiments for chemically diverse hydrophobic organic compounds (HOCs: PCP, PAHs, HCB, HCHs, PCBs, and TCDD/Fs). The above mentioned compounds were analyzed by both GC-LRMS (gas chromatography coupled with low resolution mass spectrometry (GC-HRMS) and GC-HRMS (gas chromatography coupled with high resolution mass spectrometry). Also the the leachability of eleven selected PCBs from naturally aged soil (Västervik, Sweden) was investigated in relation to the composition and concentration of dissolved organic matter at different pH (2 to 9), using a pH static test with initial acid/base addition. The the composition and of dissolved organic matter (DOM) at different pH values was explored by FTIR spectroscopy. The results were evaluated by orthogonal projections to latent structures (OPLS). Generally, for all model compounds studies, the Kd-values showed a variability of 2-3 orders of magnitude depending on the matrix composition. The Kd-values of moderately hydrophobic compounds, (e.g. HCHs, PCP and Phe), were correlated mainly with the organic matter content of soil. For more hydrophobic compounds (e.g.BaA, HCB and PCB 47), the leachability decreased as the proportions of  OM and clay contents increased. The Kd-values of 1,3,6,8-TCDD and 1,3,6,8-TCDF were  positively correlated with peat content but negatively correlated with clay content, while for PCB 153 and PCB 155 the correlations were reversed. The log Kd-values of all target PCBs decreased with increased pH values and the log Kd-values were highly correlated with the concentration of total organic carbon (TOC) in the leachates. The FTIR analysis of DOM showed that the least chlorinated and hydrophobic PCB congeners (i.e. PCB 28) might be associated with the hydrophilic fraction (i.e. carboxylic groups) of DOM. Our study demonstrated how complex interaction between the organic matter, clay components, pH and DOC influences the leachability of HOCs in a compound-specific manner.

Antiphospolipidsyndrome (APS) is one of the most common autoimmune diseases characterized bythrombosis, fetal loss and presence of antiphospholipid antibodies. In APS research the antibodies of biggestinterest are anti-β2-glycoprotein I antibodies (Aβ2GPIA). β2-glycoprotein I (β2GPI)is a plasma protein which becomes activated and obtains a open structure incontact with negative charged surface molecules such as phospholipids. Inactiveβ2GPI has a closed, circular shape which can’t bind autoantibodies. Thereis no golden standard for APS diagnosing and the methods used often giveinconsistent results. The purpose of this examination project work was toconvert β2GPI into the open and closed forms, respectively, by dialyzing againsthigh ionic strength, low and high pH and determine if there is any differencein binding capacity between the two forms and Aβ2GPIAon a microtiter plate.                                                The binding capacity was tested inan ELISA (enzyme-linkedimmunosorbent assay) using purified IgG from patient sera and thedifferent conformational forms of β2GPI. An ELISA for measuring of Aβ2GPIAon several patient samples was also performed.               No difference in binding capacitycould be detected which might be explained by that the conversion of β2GPI was unsuccessful.Perhaps no difference can be measured between the structures because the closedform is expected to open on microtiter plates. An unexpected result was thepresence of immune complexes of β2GPI-Aβ2GPIA found in the serum of one of the patients. In theory an ELISA based on theopen form of β2GPI would provide more reliable diagnoses and furtherresearch is needed in this area.

Steel slag is a by-product from steel production and has potential to act as a sorbent for several contaminants. Contaminated water is a global problem and cheap and simple remediation solutions are often sought. The potentials are many to use an industrial residue for water purification purposes e.g. low cost. The absorption efficiency was evaluated for two different steel slags further divided into two grain sizes, <0.9 mm and 0.9-2 mm. Laboratory experiments was conducted for three anionic elements; bromine, chromate and molybdate. Controlled parameters were; time, sorbent amount and sorbate concentration. The sorption was primarily dependent on the grain size and the smaller grain size had a higher sorption of all three tested anionic species. Unfortunately the results are partially affected by the release of the tested elements from the sorbent itself.

Per- and polyfluorinated alkyl substances (PFASs) belong to a large group of man-made chemicals that pollute the environment. Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are the most commonly found PFASs. The pollution of PFASs can be caused among others by using of aqueous fire-fighting foams (AFFFs). PFASs are persistent compounds; that can travel long distances and bioaccumulate in biota. There are several exposure routes for PFASs, but the most common are via food and drinking water. A possible way for PFASs to enter the food chain is by adsorption to microbes. In this project, binding of PFASs to three gram-negative bacteria, Eschericha coli, Acidovorax delafieldii and Pseudomonas nitroreducens, was assessed. Microbes were exposed for fluorinated compounds in environmental water samples and a PFAS-11 solution with 11 PFAS substances prepared in the laboratory. The binding seems to be preferential to the most abundant compounds, PFOS, since the second most abundant compound in the samples was PFHxS with concentrations at one third of the PFOS concentration but nonetheless PFHxS was not detected in any of the samples. The binding of mainly one PFAS was identified; PFOS was bound at highest concentrations in E. coli treated with both environmental water sample and a PFAS-11 solution. Low concentrations of FOSA and PFDoDS were identified in E. coli and PFNA in A. delafieldii. Only PFOS was detected in P. nitroreducens. The concentrations of other PFASs were below their respective method detection limits.

Rapporter och studier har berättat att svenska elever tappar intresse för de naturvetenskapliga ämnena under högstadietiden. Arbetssätt och lektionsinnehåll är viktiga faktorer som kan påverka elevernas intresse för de naturvetenskapliga ämnena positivt. Flera pilotstudier har undersökt specifika arbetssätt på elevernas intresse under begränsade tidsperioder med varierande resultat. Tyvärr finns det inga generella riktlinjer med beprövade arbetssätt som vetenskapligt bevisat ökar elevernas intresse under högstadietiden. Syftet med denna studie är att undersöka om kemiintresset hos elever i årskurs nio påverkas av olika arbetssätt i undervisningen. Empirisk data insamlades till en kvantitativ studie genom en enkätundersökning som besvarades av 83 elever i årskurs nio på två högstadieskolor i Sverige. Enkäten bestod av stängda och öppna enkätfrågor. Dataanalysen av de öppna frågorna gjordes genom det pragmatiska perspektivet och teorier om situationsbaserat intresse. Resultatet visade att en åttondel av de tillfrågade eleverna ansåg att lektionsinnehållet på kemilektionerna intresseväckande. Det arbetssätt som var mest effektiv till att påverka elevernas ämnesintresse positivt var laborationer i kemi. Vid genomgångar var det särskilda attribut hos den undervisande läraren som var avgörande för att eleverna skulle utveckla ett situationsbaserat intresse. Grupparbeten kan påverka elevernas intresse i en positiv riktning förutsatt att det finns en bra gruppdynamik i den aktuella arbetsgruppen. Det arbetssätt som eleverna var mest negativa till var individuellt arbete på grund utav att det upplevdes som monotont och tråkigt. Resultatet av denna studie kan användas som riktlinje för undervisande kemilärare för att öka det situationsbaserade intresset i kemiundervisningen.

The main focus of this thesis has been directed towards developing novel surface-confined transition metal complexes for applications in heterogeneous catalysis and for the preparation of anisotropic particle surfaces. The first part describes the heterogenization of a homogeneous transition metal-based catalyst tetraphenyl cobalt porphyrin (CoTPP) on silicon wafers and on silica particles. The activity in hydroquinone oxidation for the silica particle-immobilized CoTPPs was found to be increased 100-fold compared to its homogeneous congener whereas the silicon wafer-immobilized CoTPPs achieved lower activity due to the formation of clusters of catalyst molecules on the support surface as detected with atomic force microscopy (AFM). The second part of this thesis describes the development and characterization of anisotropic particle-surfaces by electrochemical site-specific oxidation of surface-confined thiols. Reactive patches or gold gradients could be obtained on the particle surfaces depending on the type of working electrode used and on the electrolyte composition. The particle surface functionalities were characterized with X-ray photoelectron spectroscopy (XPS) and the particle-surface-confined patches and gradients were conjugated with proteins to obtain fluorescence for investigation using fluorescence microscopy. Gold-functionalized siliceous mesocellular foams were further demonstrated to be highly efficient and selective catalysts in the cycloisomerization of 4-alkynoic acids to lactones. The final part of this thesis describes the preparation and characterization of palladium nanoparticles heterogenized in the pores of siliceous mesocellular foam. The nanoparticles were analyzed with transmission electron microscopy (TEM) and found to have a size of 1-2 nm. Primary- and secondary benzylic- and allylic alcohols were oxidized by the heterogeneous palladium nanoparticles in high to excellent yields using air atmosphere as the oxygen source. The nanopalladium catalyst was used up to five times without any decrease in activity and the size of the nanoparticles was retained according to TEM. / <p>At the time of doctoral defence the following paper were unpublished and had a status as follows: Paper1: Manuscript; Paper 4: Manuscript</p>

Green liquor dreg (GLD) is a residual product that could be a solution to the problem with acid rock drainage. More information about how this material reacts and is affected when in contact with acid rock drainage (ARD) is needed. Different acidic media was used to investigate trace element leaching and the possible spectral changes using FTIR. It was possible to detect changes between samples based on the exposure for different acidic conditions. Most peaks were found below 1 500 cm-1 which complicates the interpretation. For enabling the use of multivariate analysis the spectral data needed to be pre-treated and after this it was possible to see groupings and directions based on exposure. Different tendencies are seen for the trace elements, where some element leaching increased at lower pH and some elements decreased leaching at lower pH. This could partly be due to the formation of salts with low solubility such as gypsum and anglesite when leached with sulphuric acid.

The two additive brominated flame retardants, tetrabromoethylcyclohexane (TBECH) and hexabromocyclododecane (HBCD) are used to prevent fire to start and spread. They are simply mixed with material and are most likely to leach out in the environment, because of non-covalently binding to the material. TBECH can exist as four pairs of enantiomers, α-, β-, γ- and δ-TBECH. The technical HBCD can exist as three pairs of enantiomers, α-, β- and γ-HBCD and two meso forms δ- and ε-HBCD. None of these compounds are produced in Sweden, but they are imported to industries. TBECH has been found in Beluga blubber and can accumulate in zebrafish. HBCD has been found in water environments and can be toxic to and bioaccumulate in water-living animals. In this study, a method was developed for separation and detection of α-, β-, γ- and δ-TBECH on HRGC/HRMS. All TBECH-isomers could be separated with the developed method. How much of the TBECH isomers that were recovered after applying existing extraction and clean-up procedures, normally applied for clean-up and extraction of PCBs and PCDD/Fs, was evaluated. Low recovered amounts (6.8-35.5 %) of TBECH-isomers added in known amounts to three different whale samples indicate severe evaporation losses and possibly photolytic degradation. None of the four enantiomers were detected in the three whale samples. For HBCD analysis, both the chromatography and MS/MS parameters were optimised for δ- and ε- HBCD yielding good chromatography and sensitivity. However, due to technical difficulties during the time-period of this project, no whale samples could be analysed for HBCD on UPLC/MS/MS.