The high throughput capabilities of protein mass fingerprints measurements have made mass spectrometry one of the standard tools for proteomic research, such as biomarker discovery. However, the analysis of large raw data sets produced by the time-of-flight (TOF) spectrometers creates a bottleneck in the discovery process. One specific challenge is the preprocessing and identification of mass peaks corresponding to important biological molecules. The accuracy of mass assignment is another limitation when comparing mass fingerprints with databases.;We have developed an automated peak picking algorithm based on a maximum likelihood approach that effectively and efficiently detects peaks in a time-of-flight secondary ion mass spectrum. This approach produces maximum likelihood estimates of peak positions and amplitudes, and simultaneously develops estimates of the uncertainties in each of these quantities. We demonstrate that a Poisson process is involved for time-of-flight secondary ion mass spectrometry (TOF-SIMS) and the algorithm takes the character of the Poisson noise into account.;Though this peak picking algorithm was initially developed for TOF-SIMS spectra, it can be extended to other types of TOF spectra as soon as the correct noise characteristics are considered. We have developed a peak alignment procedure that aligns peaks in different spectra. This is a crucial step for multivariate analysis. Multivariate analysis is often used to distill useful information from complex spectra.;We have designed a TOF-SIMS experiment that consists of various mixtures of three bio-molecules as a model for more complicated biomarker discovery. The peak picking algorithm is applied to the collected spectra. The algorithm detects peaks in the spectra repeatably and accurately. We also show that there are patterns in the spectra of pure biomolecules samples. Furthermore, we show it is possible to infer the concentration ratios in the mixture samples by checking the strength of the patterns.

Nuclear Magnetic Resonance (NMR) is a technique with several advantages, such as high rapidity and easy operation as no sample specific standard or sample derivatization is required. Proton NMR is the most common NMR experiment, since hydrogen is “NMR active” and present in most organic compounds. Because of this, there is a high risk of overlapping signals in 1H-NMR spectra in samples containing multiple components, e.g. pharmaceutical preparations. Since Fluorine (19F) is “NMR active”, but not as common in organic molecules as hydrogen, peak overlapping is unlikely. A quantitative 19F-NMR method was therefore developed in this study.   Certain parameters (number of scans, relaxation delay, excitation frequency, pre-scan delay, spectral width & pulse angle) were examined during the method development, based on samples containing fludrocortisone acetate and 4,4´-difluorobenzophenone. For evaluation of the developed method, experiments were set up with different active pharmaceutical ingredients as well as pharmaceutical products. Good linearity and precision was obtained, and conclusions from the research experiments are that the developed method gives reliable purities compared to the reference method 1H-qNMR, and can therefore be used to achieve estimated assays on pharmaceutical raw materials. The method is also applicable on analysing registered pharmaceutical products as well as determining whether the strength of a suspected illegal drug is within the therapeutic range or not. Finally, the range of the method was determined to approximately 1-20 mg/mL, if examined on a 300 MHz NMR instrument.

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.

In this study, two, three, four, five, and six rare earths were separated by reversed-phase thin layer chromatography. Selected sample spots were removed from the plate and determined by emission spectroscopy. Di-(2-ethylhexyl)phosphoric acid was used as the stationary phase. This roganic substituted inorganic acid is retained on the adsorbent through hydrogen bonding and is essentially hydrophobic, so that the aqueous mobile phase can pass over it without serious interaction between the two acids.

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Chemical weapon attacks are a persistent and evolving global threat requiring novel mitigation and defense strategies. Porous Metal-Organic Frameworks (MOFs) are amenable for a wide-range of protective applications against hazardous chemical agents, including chemical warfare agents (CWAs), given their highly tunable chemical and structural architecture. The zirconium-based UiO MOFs, in particular, offer a high degree of chemical, structural and thermal stability making them ideal candidates for filtration and decontamination applications. In this dissertation, a combination of in situ Temperature-Programmed Infrared (TP-IR) spectroscopy and Temperature-Programmed Desorption Mass Spectrometry (TPD-MS) are applied to understand the uptake, transport and desorption interactions of the nerve agent simulant, dimethyl methylphosphonate (DMMP) and complementary benign, potential alternative simulants, including acetone, isopropanol and n-heptane. The use of CWA simulants provides detailed information on the structure-activity relationship of live CWA agents and MOFs, while minimizing the consequences of accidental exposure. To understand temperature-dependent MOF-analyte interactions, the intrinsic thermal response of UiO MOFs is investigated revealing negative thermal expansion using a combination of TP-IR, TPD-MS and synchrotron X-ray Diffraction for UiO-67 MOFs. Ultimately, this multi-technique approach enables a fundamental understanding of CWA simulant interactions with single component MOFs and informs the rational design of superior sorbent materials with diverse functionality capable of selectively capturing, transporting and degrading hazardous chemicals. / Chemistry

Ion pair chromatography has found many uses within analytical chemistry and understanding of the chromatographic process with an ion-pairing reagent have been studied since the 1970s. The adsorption of the Ion-pairing reagent to the stationary phase is understood to be important and many studies have been dedicated to looking at the adsorption isotherms of the earlier quaternary alkylammonium ions. Trialkylamines have been found to have some advantages over quaternary alkylammonium ions and are almost exclusively used in the analysis of oligonucleotides. Despite this there is a lack of studies looking at the adsorption isotherms of these molecules. A method for determining the adsorption isotherm of triethylamine and tributylamine was recently published by Haseeb et al. (2023) were the adsorption isotherm of tributylamine displayed and unusual behaviour. This raised the question of how the adsorption isotherm of the ion-pairing reagent relates to the retention of the analytes, which is the topic of this project. The retention factor of a set of carboxylic and sulfonic acids were determined at increasing concentration of triethylamine and tributylamine. The retention data was used to assess the validity of the electrostatic retention model by Ståhlberg and the Extended thermodynamic approach by Cecchi, as both these models can be used to relate the adsorption to the retention factor. Results from triethylamine were harder to interpret and tributylamine subsequently became the main focus of the project. The results from tributylamine showed a clear division between carboxylic and sulfonic acids in terms of selectivity and determined surface potential. This could not be explained by the electrostatic retention model and led to the adoption of the Cecchi retention model. The adsorption isotherm of tributylamine was determined by two methods and used to fit the Cecchi model to the retention data of three analytes. This could potentially be used to interpret the adsorption isotherms influence on the retention factor, although the attained relationship should be questioned due to uncertainty in the determined adsorption isotherms.