<p>Different sample preparation steps prior to a detection method are often essential in analytical chemistry. In this thesis, both static extractions and on-line coupled solid-phase extractions have been studied in combination with different detection techniques. Aspects of performing sample preparations in miniaturized analytical devices and the development of poly(dimethylsiloxane) (PDMS) microchips are discussed. Polypyrrole was also evaluated as an electrochemically controllable stationary phase for solid-phase microextraction (SPME) and solid-phase extraction (SPE).</p><p>The first part of this thesis describes the extraction of an organic compound from a very complex solid matrix utilizing the pressurized-fluid extraction (PFE) technique. The presented results show that PFE is easily optimized and enables rapid extractions and extracts relatively free from interferences.</p><p>An integrated three-electrode device, which enabled electrochemical (EC) SPME under potential control, was developed. With this device, both anions and cations could be extracted employing two types of polypyrrole films. Planar micro band electrodes positioned at the end of a capillary were also used to electrochemically extract and detect anions in a miniaturized flow system. Different analyte concentrations and preconcentration times were examined, and good linear correlations were found between the extraction time and the detection response. The on-line coupling of a thin layer EC cell, with a polypyrrole coated working electrode, to different mass spectrometric (MS) techniques is also described and evaluated. The results show that EC-SPE, employing polypyrrole as stationary phase, can be used as a preconcentration step prior to detection.</p><p>In addition, this thesis describes the development and on-line coupling of a microelectrode array equipped PDMS microchip with an integrated graphite electrospray emitter to electrospray ionization (ESI) MS. The system enabled short transfer times and an EC conversion efficiency of 30% at a flow rate of 0.5 μL/min. The on-line EC/ESI-MS experiments were significantly simplified using a wireless Bluetooth battery-powered EC instrument.</p>

<p>This thesis covers a wide range of analytical method development for lipid analysis in complex biological samples; from sample preparation using pressurized fluid extraction (PFE) and separation with reversed phase capillary liquid chromatography (RP-LC) to detection by electrospray ionization mass spectrometry (ESI/MS) and tandem MS.</p><p>The requirements for fast, reliable and selective extraction methods with minimal usage of solvents have accelerated the development of new extraction techniques. PFE is one of the new automated, fast and efficient liquid extraction techniques which use elevated temperature and pressure with standard liquid solvents. In this thesis the reliability and efficiency of the PFE technique was investigated for the extraction of total lipid content from cod, herring muscle and human brain tissue as well as for pesticides from fatty foodstuffs. Improved or comparable efficiencies were achieved with reduced time and solvent consumption as compared to traditional methods. </p><p>A RP-LC coupled online to ESI/MS for the analysis of phosphatidylcholine (PC) and sphingomyelin (SM) molecular species was developed and used for the analysis of brain lipids from eight groups of mice treated with vehicle and various neuroleptics. The effect of postnatal iron administration in lipid composition and behavior was investigated. Whether or not these effects could be altered by subchronic administration of the neuroleptics (clozapine and haloperidol) were examined. The results support the hypothesis that an association between psychiatric disorders, behavior abnormalities and lipid membrane constitution in the brain exists.</p><p>Finally, a tandem MS precursor ion scan was used to analyze the developmental profile of brain sulfatide accumulation in arylsulfatase A (ASA) deficient (ASA -/-) as compared to wild type control (ASA +/+) mice. The ASA -/- mice were developed as a model of the monogenic disease metachromatic leukodystrophy with an established deficiency of the lysosomal enzyme ASA. The results showed that an alteration in the composition of sulfatide molecular species was observed between the ASA -/- and ASA +/+ mice.</p><p>This thesis shows that modern analytical methods can provide new insights in the extraction and analysis of lipids from complex biological samples.</p>

<p>The positron emitting radionuclide ⁶⁸Ga (T_1/2 = 68 min) might become of practical interest for clinical positron emission tomography (PET). The metallic cation, ⁶⁸Ga(III), is suitable for complexation with chelators, either naked or conjugated with biological macromolecules. Such labelling procedures require pure and concentrated preparations of ⁶⁸Ga(III), which cannot be sufficiently fulfilled by the presently available ⁶⁸Ge/⁶⁸Ga generator eluate. This thesis presents methods to increase the concentration and purity of ⁶⁸Ga obtained from a commercial ⁶⁸Ge/⁶⁸Ga generator. The use of the preconcentrated and purified ⁶⁸Ga eluate along with microwave heating allowed quantitative ⁶⁸Ga-labelling of peptide conjugates within 15 min. The specific radioactivity of the radiolabelled peptides was improved considerably compared to previously applied techniques using non-treated generator eluate and conventional heating. A commercial ⁶⁸Ge/⁶⁸Ga generator in combination with the method for preconcentration/purification and microwave heated labelling might result in an automated device for ⁶⁸Ga-based radiopharmaceutical kit production with quantitative incorporation of ⁶⁸Ga(III).</p><p>Macromolecules were labelled with ⁶⁸Ga(III) either directly or via a chelator. The bifunctional chelator, DOTA, was conjugated in solution to peptides, an antibody and oligonucleotides. The peptides had varied pI values, constitution, and length ranging from 8 to 53 amino acid residues. The oligonucleotides were of various sequences and length with modifications in backbone, sugar moiety and both 3' and 5' ends with a molecular weight up to 9.8 kDa. The bioconjugates were labeled with ⁶⁸Ga(III), and the resulting tracers were characterised chemically and biologically. The identity of the ⁶⁸Ga-labelled bioconjugates was verified. The tracers were found to be stable and their biological activity maintained. Specific radioactivity was shown to be an important parameter influencing the feasibility of accurate imaging data quantification.</p><p>Furthermore, ⁶⁸Ga-labelled peptide imaging was shown to be a useful tool to study peptide adsorption to microstructures in a chemical analysis device.</p>

<p>The acceptance of blood contacting implants creating favorable conditions <i>in vivo</i> is decisively determined by their interaction with proteins that mediate inter cellular interactions with synthetic substrates. Adsorbed proteins can activate blood cascade systems like coagulation and complement that may result in serious blood clots, and/or immunological reactions. Poly (ethylene glycol) (PEG), heparin, and phosphoryl choline (PC) functional poly (methacrylates) are previously used polymers with known non-adhesive properties in blood contacting events.</p><p>This thesis contributes to this extensive research by introducing a novel type of biomaterial that equips biodegradable polymers with biomimetic functionalities. The phospholipid mimetic material is synthesized by combining biodegradable polymers with various functional polar end-groups consisting of zwitterionic phosphoryl choline (PC), anionic succinates, and cationic quaternary ammonium. The polymer backbone provides mechanical stability and biodegradability whilst the various head groups provide a variety of functions. The careful evaluation of the synthesis has allowed reaction conditions to be optimized leading to complete conversion at each step and subsequently high yields. Initially, poly (e-caprolactone) (PCL) was used since it provided a suitable synthetic starting point. However, the synthesis has also included poly (trimethylene carbonate) (PTMC) to provide a material that allows spontaneous surface enrichment of the polar PC group. This was achieved with an added hydrophilic environment. </p><p>Through the synthesis of multi PC functional PTMC, additional bulk organisation by the formation of zwitterionomers (PC ionomer) was achieved. Low modulus elasticity and water uptake were some of the properties of the formed material. As a result it was shown that the PC ionomer could be used for protein/drug loading and subsequent release. Furthermore, the material possessed non-adhesive properties in different biological environments.</p><p>Importantly, the result suggests that a versatile synthetic platform has been established that may provide a smorgasbord of different functional polymers, or combinations of such. This is indeed important since it was shown that the polymer in many ways dictates how the material may take advantage of an added functionality. </p><p>Such materials should be interesting for a variety of biomedical applications including the production of soft hemocompatible tissue.</p>

<p>Thin metal films have found their use in many magnetic devices. They form pseudo two-dimensional systems, where the mechanisms for the magnetic interactions between the layers are not completely understood. Layered crystal structures have an advantage over such artificial systems, since the layers can be strictly mono-atomic without any unwanted admixture. In this study, some model systems of layered magnetic crystal structures and their solid solutions have been investigated by x-ray and neutron diffraction, Mössbauer and electron spectroscopy, heat-capacity and magnetic measurements, and first-principle electronic structure calculations, with the goal of deepening our understanding through controlled chemical synthesis.</p><p>The compounds TlCo₂S₂, TlCo₂Se₂ and their solid solution TlCo₂Se_2-xS_x, all containing well separated cobalt atom sheets, order with the moments ferromagnetically aligned within the sheets. In TlCo₂S₂, the net result is ferromagnetism, while TlCo₂Se₂ exhibits antiferromagnetism. The inter-layer distance is crucial for the long-range coupling, and it was varied systematically through Se-S substitution. The incommensurate helical magnetic structure found for TlCo₂Se₂ (x = 0) prevails in the composition range 0 ≤ x ≤ 1.5 but the pitch of the helix changes. The accompanying reduction in inter-layer distance on sulphur substitution varies almost linearly with the coupling angle of the helix. An additional competing commensurate helix (90°) appears in the medium composition range (found for x = 0.5 and 1.0).</p><p>The systems TlCo_2-xMe_xSe₂ show helical magnetic ordering for Me = Fe or Cu, while a collinear antiferromagnetic structure occurs for Me = Ni. Magnetic order is created by iron substitution for copper in the Pauli paramagnetic TlCu₂Se₂, but now with the moments perpendicular to the metal sheets.</p><p>TlCrTe₂ forms a quite different crystal structure, with intra-layer ferromagnetic alignment and net collinear antiferromagnetism. In contrast to the other phases, the values of the moments conform well to a localised model for Cr³⁺.</p>

<p>In medicinal chemistry, there is a constant need for new preparative methods, both to make the synthesis process more effective, and to increase the accessibility to a wide variety of compounds. A number of different approaches can be used to attain these goals. Transition metal catalysis is generally performed under mild conditions, providing both regio- and chemoselective reactions. Thus, it offers an attractive means of preparation of complex drug candidates. Two additional methodologies used to increase the preparative efficiency are one-pot protocols and controlled microwave heating. One-pot and multi-component reactions are less time consuming than step-by-step reactions, and microwave heating has been used to considerably shorten the reaction times. </p><p>This thesis describes a new palladium-catalyzed, one-pot reaction producing racemic acetal-protected 3-hydroxy-1-indanones from ethylene glycol vinyl ether and triflates of salicylic aldehydes. The triflates were prepared using controlled microwave heating. The reaction sequence starts with a regioselective internal Heck coupling, followed by an annulation cascade. By including secondary amines in the reaction mixture, the reaction was further developed into a three-component reaction delivering racemic acetal-protected 3-amino-1-indanones. This new method was utilized for the synthesis of primary, secondary and tertiary aminoindanones. Finally, by using enantiopure t-butyl sulfinyl imines, derived from salicylic aldehyde triflates and ethylene glycol vinyl ether as starting materials in a closely related type of palladium coupling–annulation sequence, a stereoselective protocol providing enantiomerically pure 3-amino-1-indanones was developed. To demonstrate an application in medicinal chemistry, the enantiopure 3-amino-1-indanones were incorporated as P2 and/or P2´ substituents into active HIV-1 protease inhibitors.</p>

<p>This thesis describes an interdisciplinary project, where the aim is to mimic the initial reactions in photosynthesis. In photosynthesis, the absorption of light is followed by the formation of charge-separated states. The energy stored in these charge-separated states is further used for the oxidation of water and reduction of carbon dioxide. In this thesis the photo-induced processes in a range of supramolecular complexes have been investigated with time resolved spectroscopic techniques. The complexes studied consist of three types of units; photosensitizers (P) capable of absorbing light, electron acceptors (A) that are easily reduced and electron donors (D) that are easily oxidised. Our results are important for the future design of artificial photosystems, where the goal is to produce hydrogen from light and water. </p><p>Two molecular triads with a D-P-A architecture are presented. In the first one, a photo-induced charge-separated state was formed in an unusually high yield (φ>90%). In the second triad, photo-irradiation led to the formation of an extremely long-lived charge-separated state (τ = 500 ms at 140K). This is also the first synthetically made triad containing a dinuclear manganese unit as electron donor.</p><p>Further, two sets of P-A dyads are presented. In both, the expected photo-induced reduction of the electron acceptor is diminished due to competing energy transfer to the triplet state of the acceptor.</p><p>Finally, a P-P-A complex containing two separate photosensitizers is described. The idea is to produce high-energy charge-separated states by using the energy from two photons.</p>

<p>One-step photoinitiated free radical carbonylation was employed for the rapid (5–7 min) labelling of aliphatic carboxylic acids, esters, and amides with a short-lived positron emitter ¹¹C (t_½ = 20.3 min) at the carbonyl position. The labelled compounds were synthesized from alkyl iodides (0.05–0.1 mmol), [¹¹C]carbon monoxide, and appropriate nucleophiles. Decay-corrected radiochemical yields were up to 74%; conversion of [¹¹C]carbon monoxide reached 85–90%; specific radioactivity was 158–192 GBq/mmol. The labelled compounds were identified and characterized using HPLC, LC-MS, and ¹H and ¹³C NMR. The effects of solvents, additives, photoirradiation, temperature, and reaction time were studied and discussed.</p><p>[<i>carbonyl-</i>¹¹C]Amides were synthesized using amines in 1–2 equiv. to iodides, exploiting solvent effects to control reactivity. [<i>carboxyl-</i>¹¹C]Acids were synthesized using water as a nucleophile, in binary and ternary aqueous solvent mixtures; the addition of TBAOH or KOH was necessary to obtain high radiochemical yields. [<i>carbonyl-</i>¹¹C]Esters were synthesized using primary and secondary alcohols, <i>tert-</i>butanol, and phenol. Bases were KOH, BuLi, LiHDMS.</p><p>The effects of photosensitizers were studied and exploited to accelerate the labelling of carboxylic acids and esters resulting in 75–85% decay-corrected radiochemical yields under mild conditions without the use of bases.</p><p>A mild procedure for the ¹¹C-carboxylation of alkyl iodides using DMSO as an oxygen nucleophile was developed. This method is expected to be suitable in the macroscale synthesis of carboxylic acids using isotopically unmodified carbon monoxide.</p><p>Radical carbonylation was applied to improve the synthesis of an extensively used PET tracer, [<i>carbonyl</i>-¹¹C]WAY-100635. The tracer was synthesized in one step, whereas a common approach via Grignard reagents requires three steps.</p><p>In addition, several (¹³C)compounds were synthesised using the described methods.</p><p>Free radical carbonylation may be used for the ¹¹C-carbonylation of alkyl iodides, whereas transition-metal carbonylation – of aryl halides and triflates. Thus, the two carbonylation methods are complementary with respect to the scope of synthetic targets.</p>

<p>The challenge for the future was defined by the Brundtland Commission (1987) and by the Rio Declaration (1992), in which the fundamental principles for achieving a sustainable development were provided. Sustainable chemistry can be defined as the contribution of chemistry to the implementation of the Rio Declaration. This thesis shows how Pressurized Fluid Extraction (PFE) can be utilized in chemical analysis, and how this correlates to Green Chemistry.</p><p>The reliability and efficiency of the PFE technique was investigated for a variety of analytes and matrices. Applications discussed include: the extraction of the antioxidant Irganox 1076 from linear low density polyethylene, mobile forms of phosphorus in lake sediment, chlorinated paraffins from source-separated household waste, general analytical method for pesticide residues in rape seed, total lipid content in cod muscle, and squalene in olive biomass. Improved or comparable extraction yields were achieved with reduced time and solvent consumption. The decrease in use of organic solvents was 50-90%, resulting in minimal volatile organic compounds emissions and less health-work problem. Due to higher extraction temperatures and more efficient extractions, the selection of solvent is not as important as at lower temperatures, which makes it possible to choose less costly, more environmentally and health beneficial solvents. In general, extraction times are reduced to minutes compared to several hours. As a result of the very short extraction times, the amount of co-extracted material is relatively low, resulting in fewer clean-up step and much shorter analysis time. Selective extractions could be obtained by varying the solvent or solvent mixture and/or using adsorbents. </p><p>In this thesis, the PFE technique was compared to the twelve principles of Green Chemistry, and it was shown that it follows several of the principles, thus giving a major contribution to sustainable chemistry. </p>

<p>Processes where a molecule absorbs visible light and then disposes of the excess energy via electron/energy transfer reactions have an important role both in nature (e.g. in photosynthesis) and in many technical applications (e.g. in photography and photovoltaics). This thesis uses different spectroscopical techniques, mainly ultrafast transient absorption, to study such processes. The thesis can roughly be divided into three parts.</p><p>In the first part, donor-acceptor systems linked by different conjugated bridges are studied. The objective was to see to what extent the conjugated link could enhance excited state energy or electron transfer, via so-called superexchange processes. The studied links do enhance the electron/energy transfer but in the electron transfer study the resulting charge separated state was very short lived.</p><p>The second part explores the possibility of constructing acceptor-donor-acceptor triads where the direction of electron transfer is determined by the electronic state of the donor. Direct evidence of electron transfer in the form of radical absorption was found from both the first and the second excited states of the donor.</p><p>In the last part, two common chromophores were investigated by transient absorption anisotropy. In the case of Ru(bpy)₃²⁺, it was found that the complex lost all memory of the polarization of the exciting light much faster than what was previously thought. This means that electron transfer between ligands is normally not the rate limiting step in electron transfer reactions involving this complex. In the case of zinc porphyrin, it was seen that the measured anisotropy differed depending on which electronic state was excited suggesting differences in the degree of coherence.</p>