A multiplexed method for performing MS/MS on multiple ions simultaneously in a miniature rectilinear ion trap (RIT) mass spectrometer has been developed. This method uses an ion encoding procedure that relies on the mass bias that exists when ions are externally injected into an RIT operated with only a single phase RF applied to one pair of electrodes. The ion injection profile under such conditions ions is Gaussian-like over a wide range of RF amplitudes, or low mass cutoff (LMCO) values, during ion accumulation. We show that this distribution is related to ion m/z, and is likely caused by ions having an optimal range of pseudo-potential well depths for efficient trapping. Based on this observation, precursor ion intensity changes between two different injection LMCO values can be predicted, and these ion intensity changes are found to be carried through to their corresponding product ions, enabling multiplexed MS/MS spectra to be deconvoluted. The gas-phase reactions of a series of coordinatively unsaturated [Ni(L) n]y+ complexes, where L is a nitrogen-containing ligand, with chemical warfare agent (CWA) simulants in a miniature rectilinear ion trap mass spectrometer were investigated as part of a new approach to detect CWA. Results show that the metal complex ions can react with low concentrations of several CWA simulants, including dipropyl sulfide (simulant for mustard gas), acetonitrile (simulant for the nerve agent tabun), and diethyl phosphite (simulant for nerve agents sarin, soman, tabun, and VX), thereby providing a sensitive means of detecting these compounds. The [Ni(L)n] 2+ complexes are found to be particularly reactive with the simulants of mustard gas and tabun, allowing their detection at low parts-per-billion (ppb) levels. These detection limits are well below the median lethal doses for these CWAs, which indicates the applicability of this new approach, and are about two orders of magnitude lower than electron ionization detection limits on the same mass spectrometer. The use of coordinatively unsaturated metal complexes as reagent ions offers the possibility of further tuning the ion-molecule chemistry so that desired compounds can be detected selectively or at even lower concentrations. Mass spectrometry has become a tool for studying noncovalently bound complexes. Specifically, electrospray ionization mass spectrometry (ESI-MS) has found increasing use for the determination of affinity (Ka) or dissociation (Kd) constants. Direct measurement of the equilibrium components by ESI-MS is the most straightforward approach for determining binding equilibrium constants, but this approach is prone to error and has some inherent limitations. Transferring complexes from solution to the gas phase may perturb the equilibrium concentrations and/or different ionization efficiencies may cause the resulting ion signals not to reflect actual solution concentrations. Furthermore, ESI only works under a limited range of solvent conditions (i.e. low ionic strengths), which limits the broad applicability of this approach. We propose an approach based on covalent labeling in the context of metal-catalyzed oxidation (MCO) reactions that, when combined with MS, overcomes such limitations when determining metal-ligand binding constants. The MCO-MS approach will provide concurrent information regarding metal binding site and metal-protein binding affinity. Optimization of the MCO reaction through isotopic mass tags will permit enhanced identification of modified residues. Application of this method to study the affinity and binding interactions of other divalent metals with β2m are likely to provide insight into the specificity of copper for causing β2m amyloid formation.

In the first part of this project a refractive index sensor was designed that will ultimately allow the study of ligand-protein and protein-protein interactions. The setup consists of a flow cell that contains an integrated optics Mach-Zehnder interferometer chip, into which laser fight can be introduced by end- or prism-coupling. The optical parameters of the interferometer were chosen to achieve sensitivities as low as 0.07 ng/cm2. Optimized procedures for the interferometer fabrication, dimensions of the individual sensor parts as well as parameters for the optical alignment are described in great detail. While successful light coupling into the waveguiding channel of the interferometer was achieved, improvements in the light conductivity of the titanium-silica waveguides are still necessary to make this setup work. A second issue of this thesis is the preparation of a polymeric matrix for biosensors, that consists of dextran functionalized with nickel(II)nitrilotriacetic acid (NiNTA-dextran) and the characterization of its binding affinity toward histidine oligopeptides and histidine-tagged proteins by isothermal titration calorimetry (ITC). Enhanced binding affinities of the oligopeptides to NiNTA-dextran relative to NiNTA that are due to polyvalent interactions between the NiNTA-moieties on the modified dextran and neighboring histidine groups in the peptides were found. An increase in the strength of the interaction between NiNTA-dextran and the oligohistidines was observed as the number of histidine residues in the oligopeptide were increased. Proteins with at least four neighboring histidine groups are expected to be particularly suited for the generation of stable affinity matrices out of NiNTA-dextran. A decrease in the stability of the NiNTA-dextran matrices that are loaded with histidine-tagged proteins by buffering reagents was demonstrated, underscoring the importance of choosing an appropriate buffer system in biosensor applications. Finally a model for the structure of complexes between Ni-NTA and oligohistidine residues is proposed based on the stoichiometry of binding observed by ITC.

Microwave-enhanced extraction is gaining in popularity because it allows for faster extraction, reduced solvent use, and high recovery efficiency compared to traditional methods such as Soxhlet extractions. The elevated temperatures and pressures applied to samples during microwave-enhanced extraction have the potential to accelerate abiotic degradative reactions producing artifactual apparent breakdown products absent from the original samples. In addition, humic substances have been shown to shuttle electrons between donors and acceptors. Because chlorinated organic compounds have proven to be good electron acceptors and because ferrous iron is often present in anoxic soils, the possibility appeared to exist that reductive dechlorination of chloroorganic compounds in samples of anaerobic soils and that this degradative reaction could be accelerated by the conditions applied during microwave-enhanced extraction. Aqueous solutions of between 10 and 40 μg of PCP per ml were subjected to wide ranges of temperatures and pressures in the presence of 0.4 mg/ml of humic acid extracted from a commercial peat, in the presence of 400 μg/ml of FeSO4·7H2O, in the presence of both humic acid and ferrous iron, and in the presence of neither. These four treatments were tested for four days at room temperature. These treatments were also microwaved for 30 min. at 121, 145, and 170°C, for four hours at 160, and 170°C, and for one hour at 190°C, which was the operational upper limit of the microwave-extraction, pressure vessels. In none of the four treatments, following none of the time and temperature programs, were any additional apparent dechlorination products detected. Changing the solvent from water to ethyl acetate before microwaving 40 μg/ml PCP for 30 min. also failed to promote dechlorination. Microwaving a 20-μg/ml, aqueous solution of 2,3,4-trichlorophenol with the same combinations of humic acid and ferrous iron also failed to produce any evidence of reductive dechlorination. Four hours of microwaving at 160°C also failed to effect dechlorination of either 20 μg/g of PCP in any of four different soils or of 20 μg/ml of PCP in the usual four treatments in which the peat humic acid was replaced by Aldrich humic acid.

Ab initio calculations were utilized to demonstrate the theory behind molecular properties and were correlated to actual spectroscopic results in the infrared and Raman. Symmetrical aspects of small flexible molecules were examined to determine how symmetry coordinates mix in the potential energy distribution and whether these are infrared and Raman active. The difficulty is the spectroscopic landscape of the spectrum gets extremely complicated even in very small carbon chain dihalides. The example of 1,4-dichlorobutane is provided. The work here will provide a solid reference for future research as we have found in previous work that 1,2-dibromopropane, a sensitive compound, has in previous publications shown what looks to be degradation. Three other publications are in preparation allyldichlorosilane, n-butylgermane and n-butylsilane of which the two finial compounds have conformers with the same symmetry. Instrumentation has been updated to be continually maintained and upgraded to be viable and competitive. Times for crystallizations of spectroscopic compounds for the IR and Raman cold cells can exceed 50-60 hours of continuous annealing. Modification and development of equipment allowed a level of automation and a much more precise temperature control at lower temperatures that would not have been possible before.

Studies of the properties of metal cyclopentadienyl compounds were made by infra-red spectroelectrochemistry, electrochemistry, synthesis and $\sp{103}$Rh nuclear magnetic resonance spectrometry. A cell capable of simultaneously recording IR spectra of the region near the electrode surface during electrochemical experiments was developed, and characterized using ferricyanide. The absorbance-time response to potential step and potential sweep experiments was investigated and the experimentally determined response compared to a digital simulation of the response at different distances from the electrode surface. This allowed the distance from the electrode surface to the point of observation to be estimated. The capabilities of the cell were applied to the elucidation of the electrochemical behavior of titanocene dichloride and iron pentacarbonyl. Titanocene dichloride was reduced under an atmosphere of carbon monoxide to titanocene dicarbonyl and ultimately to the anion (CpTi(CO)$\sb4$) $\sp{-}$. No evidence for the formation of a titanium(III) carbonyl species was found. In contrast, reduction of titanocene dichloride in the presence of 2,6-dimethylphenylisocyanide led to the formation of titanium(III) and titanium(II) products, in which one and both of the chloride ligands had been replaced by the isocyanide, respectively. Electrochemical and chemical reduction of fulvalene-dititanium cyclopentadienyl compounds led to the breakage of the carbon-carbon bond linking the two five-membered rings of the fulvalene ligand. The electrochemical properties of a series of ferrocene-containing polyesters in solution was investigated using various stationary and rotating solid electrode techniques. The oxidised form of the polyesters coated the electrode surface in an uneven fashion allowing solution and surface processes to occur simultaneously. Evidence for the nature of this coating was gathered using X-ray photoelectron spectroscopy. The effect of substituents on a series of ring-substituted (h$\sp5$-cyclopentadienyl)dicarbonylrhodium complexes was investigated by means of changes in C-O stretching frequencies as well as $\sp{103}$Rh NMR chemical shifts. The effect of the substituents was found to be neither a purely resonance or inductive phenomenon, but best described by a substituent parameter which took both effects into account.

Within this educational endeavor instrumental development was explored through the investigation of microwave induce stable electromagnetic waves within a non-linear yttrium iron garnet ferromagnetic waveguide. The resulting magnetostatic surface waves were investigated as a possible method of rapid analytical evaluation of material composition. Initial analytical results indicate that the interaction seen between wave and material electric and magnetic fields will allow phase coherence recovery andanalysis leading to enhancement of analytical value. The ferromagnetic waveguide selected for this research was a high quality monocrystalline YIG (yttrium iron garnet) film. Magnetostatic spin waves (MSW) were produced within the YIG thin waveguide. Spin waves with desired character were used to analytically scan materials within the liquid and solid phase.

No description available.

Chemicals entering the market have been steadily increasing. The Swedish Chemicals Agency is in control of the Swedish Products Register, which is storing information on chemicals  manufactured in, transferred, or imported into Sweden. Applied to the register comes the exposure index predicting exposure of chemicals. For this study, the exposure index was used to make a first prioritization of chemicals with potential of exposure to consumers, the list of suspects were further prioritized by in silico predicted physiochemical properties. Six synthetic antioxidants 2,4-di-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,4,6-tris-tert-butyl-phenol, 2,2´-methylene-bis(4-methyl-6-tert-butylphenol), 4,4´-methylene-bis(2,6-di-tert-butylphenol), octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenol) propionate), were selected for target analysis. Great care to background contamination is applied since the analytes are used in everyday objects such as food package and personal care products. Human serum samples was collected from “Blodcentralen” in Stockholm, Sweden. Previous analytical methods exist for individual and combination for a few analytes but lacks in combination of all selected analytes. A previous method for the extraction without clean-up of some of the analytes in serum were tested but lacked in efficiency for all analytes, hence an clean-up step for removal of lipids were added. A gas chromatography mass spectrometry method was developed for simultaneous analysis of the six analytes. Four of the target analytes were detected and three were quantified (2,4-di-tert-butylphenol 2.20-3.33 ng/mL, 2,6-di-tert-butyl-4-methylphenol 3.22-3.93 ng/mL and 2,4,6-tris-tert-butyl-phenol 0.054-0.104 ng/mL). 2,2´-methylene-bis(4-methyl-6-tert-butylphenol) was detected in high concentration but due to linearity problems (R2<0.99) it was not quantified. To the best of my knowledge this is the first time that 2,4,6-tri-tert-butylphenol and 2,2´- methylene-bis(4-methyl-6-tert-butylphenol) have been detected in human serum.

No description available.

This thesis presents two new concepts for separation of micro particles using dielectrophoresis, demonstrated by calculated examples, as well as a new method for obtaining dielectric data on living cells. The thesis is based on four papers. Paper I describes how the trapping efficiency of micro particles may be significantly increased when superpositioned electric fields are employed in a high conductivity medium. Avoiding low conductivity media is important when working with living cells. Calculations were performed to predict trajectories of Escherichia coli bacteria in the system with superpositioned electric fields, and a model was developed which employed two arrays of interdigitated electrodes in a micro channel. Paper II proposes a new concept for separation of micro particles, based on repetitive dielectrophoretic trapping and release in a flow system. Calculations show that the resolution increases as a direct function of the number of trap and release steps, and that a difference in size will have a larger influence on the separation than a difference in dielectrophoretic properties. Polystyrene beads in deionized water were used as a model, and calculations were performed to predict the particle behavior and the separation efficiency. It should be possible to separate particles with a size difference of 0.2 % by performing 200 trap-and-release steps. The enhanced separation power of multi step dielectrophoresis could have significant applications, not only for fractionation of particles with small differences in size, but also for measuring changes in surface conductivity. Paper III presents a new calculation method for predicting dielectrophoretic motion of micro particles. The method is based on a soft sphere method often used in molecular dynamics. Results from the calculations are in good agreement with theoretical predictions as well as initial experimental results, showing that the method provides good efficiency and accuracy. Paper IV describes a new method for measurements of conductivity of living bacteria. To obtain reliable conductivity values, it is important to handle the cells as gently as possible during the measurement process. A standard conductivity meter was used in combination with cross-flow filtration. In this way, repeated centrifugation and resuspension is avoided which otherwise may cause damage to the bacteria. The conductivity of Bacillus subtilis was determined to be 7000 μS/cm by means of the cross-flow filtration method, and the values differ from earlier published values by almost an order of a magnitude. In addition to the work presented in the papers, some experimental dielectrophoresis work in chip-based systems was performed. The behavior of Escherichia coli and polystyrene beads at different voltages and frequencies were studied. Separation of beads with different sizes was achieved on an array of interdigitated electrodes. Using electrodes with a pointed shape, alignment in different directions, pearl-chain formation, rotation, and other dielectrophoretic motion of E. coli were observed. / QC 20101108