As the field of organocatalysis is growing, it is becoming more important to understand the specific modes of action of these new organic catalysts. Quantum chemistry, in particular density functional theory, has proven very powerful in exploring reaction mechanisms as well as selectivities in organocatalytic reactions, and is the tool used in this thesis. Different reaction mechanisms of several organocatalytic reactions have been examined, and we have been able to exclude various reaction pathways based on the calculated reaction barriers. The origins of stereoselection in a number of reactions have been rationalized. The computational method has generally reproduced the experimental stereoselectivities satisfactorily. The amino acid-catalyzed aldol reaction has previously been established to go through an enamine intermediate. In the first study of this thesis the understanding of this kind of reactions has been expanded to the dipeptide-catalyzed aldol reaction. The factors governing the enantioselection have been studied, showing how the chirality of the amino acids controls the conformation of the transition state, thereby determining the configuration of the product. In the cinchona thiourea-catalyzed Henry reaction two reaction modes regarding substrate binding to the two sites of the catalyst have been investigated, showing the optimal arrangement for this reaction. This enabled the rationalization of the observed stereoselectivity. The hydrophosphination of α,β-unsaturated aldehydes was studied. The bulky substituent of the chiral prolinol-derived catalyst was shown to effectively shield one face of the reactive iminium intermediate, thereby inducing the stereoselectivity. The transfer hydrogenation of imines using Hantzsch esters as hydride source and axially chiral phosphoric acid catalyst has also been explored. A reaction mode where both the Hantzsch ester and the protonated imine are hydrogen bonded to the phosphoric acid is demonstrated to be the preferred mode of action. The different arrangements leading to the two enantiomers of the product are evaluated for several cases, including the hydride transfer step in the reductive amination of α-branched aldehydes via dynamic kinetic resolution. Finally, the intramolecular aldol reaction of ketoaldehydes catalyzed by guanidinebased triazabicyclodecene (TBD) has been studied. Different mechanistic proposals have been assessed computationally, showing that the favoured reaction pathway is catalyzed by proton shuttling. The ability of a range of guanidines to catalyze this reaction has been investigated. The calculated reaction barriers reproduced the experimental reactivities quite well. / QC 20100719

Electrospray ionisation (ESI) coupled to mass spectrometry (MS) is one of the most important detection techniques for chemical analysis of small drugs as well as large biomolecules in life science today. In this thesis, aspects on improved compatibility between liquid based separation systems and mass spectrometric detection were investigated regarding buffers, sample preparation and analysis of polar compounds as well as peptides and protein digests for enhanced ESI-MS performance. Capillary electrophoresis (CE) coupled to ESI-MS detection, was evaluated using both a sheath flow interface and a sheathless design. The separation of peptides and small, polar compounds was optimised for both CE-ESI interfaces. The effect of sheath liquid composition was also studied with the aim to improve sensitivity in the ESI-MS detection. Polar compounds were retained and separated by capillary ion-pair chromatography coupled to ESI-MS detection. Since commonly used ion-pairing reagents are detrimental to the ESI process they were effectively removed before the ionisation by the use of a trapping column after the separation. Alternatively, the ion-pairing reagents were exchanged to volatile constituents. A method for peptide mapping by liquid chromatography (LC)-ESI-MS was developed for lactate dehydrogenase. The method was further enhanced to involve the proteolysis on-line to the LC-ESI-MS. No manual sample handling was then needed and the total analysis time decreased from 7 to 1.5 hours. The amount of information was also shown to increase in the on-line system. Finally, the on-line concept was extended to an innovative interface for direct coupling of a pumped liquid flow to an electroosmotically driven flow. This provided a valve-free sample transfer between capillary LC and CE, aiming towards increased peak capacity per unit time for the analysis of complex peptide samples.

The amyloid-β peptide is an amphiphilic peptide that exhibits self-aggregating properties, forming the amyloid fibrils that can be found in the brains of Alzheimer patients. Today it is believed that it is the soluble Aβ oligomers rather than the mature fibrils that are the main neurotoxic species. These small peptide assemblies are known to associate with lipid membranes and form pores that can transport Ca2+ into the cell, which in part could be responsible for their neurotoxic properties. However, most biophysical methods that have been developed to study Aβ target either the monomer or the mature fibrils, and not the low abundance and polydisperse oligomers. In this work, a soft ionization mass spectrometry method that retains non-covalent oligomer interactions in the gas phase has been developed. Using this method, monomeric and oligomeric Aβ (1-40) from dimers up to octamers, except heptamers, were detected in vitro. It was also possible to detect and study the effects of peptide modifications such as methionine-35 oxidation. As mass spectrometry is a non-averaging technique the aggregation kinetics for reduced and oxidized peptides are followed simultaneously, and the results showed that the oxidized form of Aβ(1-40) aggregates slower and forms lower amounts of soluble oligomers than the reduced form. Additionally, Aβ(1-40) interactions with zwitterionic SB3-14 detergent micelles were studied in the gas phase, and it was demonstrated that Aβ-micelle complexes can survive in the mass spectrometer and be identified. Detergent head group charges seem to be essential for peptide-micelle interaction, both in the gas phase and in solution as no structure induction is observed upon addition of the non-ionic detergent DDM. Overall gas phase and solution properties agree well, which is encouraging for future gas phase studies of Aβ interactions with membrane mimetics.

The present thesis is devoted to theoretical studies of light pulse propagation through different linear and nonlinear media. One dimensional holographic photonic crystals and one dimensional impurity band based photonic crystals are investigated as linear media. The effects of angular dependence of the band structures and pulse delay with respect to the light polarization are analyzed. A strict theory of nonlinear propagation of a few strong interacting light beams is presented and applied in the field of nonlinear optics. The key idea of this approach is a self-consistent solution of the nonlinear wave equation and the density matrix equations of the material beyond the so-called rotating wave approximation. The results of numerical studies led to a successful interpretation of recent experimental data [Nature, 415:767, 2002]. A theoretical study of the NO molecule by means of two-color infrared -- X-ray pump probe spectroscopy is presented. It was found that the phase of the infrared field strongly influences the trajectory of the nuclear wave packet, and hence, the X-ray spectrum. The dependence of the X-ray spectra on the delay time, the duration and the shape of the pulses are studied. / QC 20101207

Beer is a fermented alcoholic beverage that spans back to over 5000 years years ago and is consumed all over the world. Beer is usually made from malted barley but it can also be made from different cereals and starches. Beer contains both saturated and unsaturated fatty acids (FA) which are derived from the malt that is used. Unsaturated fatty acids (FA) such as linoleic and linolenic acid are sensitive to oxidation which can affect foam, smell and taste of a beer. The purpose of this study was to extract and analyse FA profile of three different types of beer, Bryggmästaren Bästa Ekologiska, 5,2:an and Premium Gold to assess the durability of these types of beer.  Beer, fermented solution, malt and wort was provided by Åbro Bryggeri. Lipid extraction was performed on the samples, lipids were extracted with soxtec for malted product and liquid-liquid extraction for beer, fermented solution and wort. The lipids were analysed with Gas-Chromatography Flame Ion Detector.  The malted products contained unsaturated FA’s where linoleic acid was the dominating FA while the beers, fermented solutions and worts contained both unsaturated FAs and saturated FAs. The unsaturated FA were erucic acid while the saturated FAs were lauric acid, myristic acid and palmitic acid. The amount of FA’s detected in the beer was extremely low which is due to the method used as some fat might have been lost out during the liquid-liquid extraction or during an evaporation step due to a leakage in the selected rotary evaporation system. The conclusion of this study was that although fatty acids were present in malt and liquids from the brewing process, the amount was too low to cause risk of either an altered taste of the beer or increased risk of oxidation of unsaturated FAs. However, due to a limitation of data from extracted- and analysed samples, this reduces the outcome of this work and a quantitative study is needed in order to determine more exact FA profiles from the analysed samples.

Coffee is one of the most consumed beverages in the world, with about 10 million tons of coffee consumed in 2021. There are a lot of steps between the coffee tree and served beverage, as there are several processing methods each contributing to differences in fragrance, aroma, and acidity. Coffee intake has shown to have health promoting effects and has been linked to lower mortality rate. The most well-known component of coffee is caffeine, a stimulant which has an awakening effect, but there are a lot more compounds which are less well known, like the chlorogenic acids. This is a family of related compounds which have antioxidative capacity and demonstrated anti-carcinogen, anti-obesity, and anti-diabetic effects in some studies. Specialty coffee is a category of coffee which has gone through a rigorous process where flavour, aroma, acidity, and a few other factors are taken into account before being graded. This poses as an extra income for some farmers, as it is more expensive than regular coffee. If climate keeps changing, this might lead to lesser opportunities for coffee farmers to grow and sell all kinds of coffee and working with higher quality, rather than higher quantity, might be a better option for the individual, as well as for the climate. RP-HPLC is a commonly used analysis method and will be used to conduct the analyses of this study. The aim of the study was to quantitatively determine the caffeine and 3-caffeoylquinic acid (3-CQA) content in artisanal processed specialty coffee in varieties with different origins and roasting grades. The coffee varieties were ground, and brewed using three methods, filter-funnel, French press and cold brew and thereafter analysed using RP-HPLC, developed from another study and configured to acquire quicker analyses. The development of the method yielded a standard curve which was used to calculate the caffeine and 3-CQA concentration in coffee samples. The results indicated that cold brews yielded higher concentrations of caffeine and 3-CQA in most cases. The least differences when comparing brewing methods within coffee varieties were seen between filter-funnel and French press coffee. The most notable difference was seen with the light roasted Ayla variety, which yielded much higher 3-CQA concentrations compared the other two varieties (Velo collective and Ureña). It can be concluded through other studies that the higher 3-CQA content could be explained by roasting grade, and that further analyses on raw coffee samples would be needed to test differences when accounting for origin, as different roasts affect the caffeine and 3-CQA content. / Kaffe är en av de mest konsumerade dryckerna i världen, med cirka 10 miljoner ton konsumerat år 2021. Det finns många steg från kaffeträd till kopp, då det finns olika sorters processning som alla bidrar till doft, smak och syrlighet. Intag av kaffe har associerats positiva hälsoeffekter och en lägre dödlighet. Den mest välkända komponenten i kaffe är koffein, en stimulant som har en uppiggande effekt, men det finns en del mindre kända komponenter, så som klorogensyrorna, som är en grupp av besläktade molekyler som har antioxidativ förmåga och uppvisat anti-carcinogena, anti-fetma och anti-diabetiska effekter i vissa studier. Specialitet-kaffe är en typ av kaffe som har gått igenom en gedigen process där smak, doft och syrlighet, samt ett flertal andra faktorer innan det betygsätts. Detta ger en möjlighet för kaffeodlare att tjäna mer pengar, då kaffet är dyrare. Om klimatförändringarna fortsätter i samma takt, så kan det leda till mindre möjligheter för kaffeodlare att försörja sig. Ett alternativ kan vara att satsa på att producera kaffe av hög kvalitet, snarare än hög kvantitet, vilket kan vara fördelaktigt även för miljön. RP-HPLC är en mycket vanlig analysmetod som användes för att utföra anlyser. Målet med denna studie var att kvantitativt bestämma koffein och 3-kaffeylkinasyra (3-CQA) koncentrationer i olika sorters hantverksmässigt processat kaffe med olika ursprung och rostgrad. De olika bryggmetoderna som utvärderades var filterkaffe, franskpress och kallbrygd (Cold Brew) och analyserades därefter genom en utvecklad RP-HPLC-metod som baserats från en tidigare studie och konfigurerats för att få snabbare analystider. En kalibreringskurva användes för att beräkna koffein- och 3-CQA-halt i de olika kaffeproverna. Resultaten indikerade att kallbryggt kaffe generellt gav högst koffein och 3-CQA koncentration i de flesta fallen. Minst skillnader mellan metoder fanns mellan filterbryggt och franskpresskaffe. Den största skillnaden sågs när man jämförde bryggmetoder på 3-CQA-koncentration, där Ayla-kaffet gav mycket högre halt gentemot de andra sorterna (Velo Collective och Ureña). Detta visade att ljusrostat kaffe ger en högre 3-CQA-halt vid bryggning, och detta kan bekräftas i andra studier som erhållit liknande resultat. Fler analyser skulle behöva göras på råa kaffebönor för att undersöka ifall ursprung påverkar halter utav koffein och 3-CQA, då rostgraden av bönan påverkar innehåll av båda.

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Syftet med den hät studien är att se vilken erfarenhet pedagoger inom förskolan har av kemi och kemiska begrepp och hur dessa används i verksamheten. Som metod har jag valt att använda mig utav en kvalitativ intervju som är av semistrukturerad karaktär. Mitt resultat visade på att det var flera av pedagogerna som upplevde en stor osäkerhet på vad ett kemiskt begrepp är och attt de sällan eller aldrig använde sig utav dem.

Tanken med undersökningen var att ta reda på hur läxläsningssituationen, för ämnet kemi, i hemmen upplevs av vårdnadshavare och elever i årskurs 7-9 och vilken inställning vårdnadshavare och elever har till läxor i kemi. Eftersom den forskning som är gjord främst är inriktad på de lägre årskurserna är det intressant att titta lite närmre på läxläsningssituationen för de högre årskurserna, då nivån på kemiundervisningen höjts och vårdnadshavare kanske inte har samma möjligheter att hjälpa sina barn med läxan. Studien gjordes med hjälp av enkäter som delades ut till alla vårdnadshavare och elever på en skola. Alla elever som deltog i studien hade samma undervisande lärare och totalt deltog 60 st. hushåll i enkätstudien. För att få ytterligare en dimension på undersökningen gjordes en intervju med den lärare som undervisar eleverna i kemi. För att få en djupare inblick i hur vardagen kan se ut med tanke på mängden läxor, och om det från undervisande lärares sida gjordes några anpassningar i innehållet av läxorna till olika elever. Resultatet blev att det i stort sett råder harmoni under läxläsningssituationen i de hushåll som valde att delta i studien. En majoritet av både vårdnadshavare och elever var positivt inställda till läxor och ansåg att kunskaperna i kemi fördjupades med hjälp av läxor. Den största anledningen vårdnadshavare i studien uppger till att de hjälper sina barn med läxan i kemi är förfrågningar från barnen. Denna förfrågan från barnen beskrivs också som en av de starkare drivkrafterna till att vårdnadshavare engagerar sig i sina barns skolarbete. Det visar sig också att de flesta vårdnadshavare tycker att läxan i kemi är anpassad efter deras barn samt att de flesta vårdnadshavare inte har något behov av att påverka kemiläxan. Även om många elever i studien uppger att de får den hjälp de vill ha, behöver det inte betyda att de vill ha någon som sitter med under hela läxläsningspasset. Den hjälp vårdnadshavarna kan ge är att se till att det finns studiero samt eventuellt svara på frågor som kan uppkomma längs vägen