Studies on petrochemicals using thermal analysis coupled to photo ionisation mass spectrometry

Die chemische Analyse von schweren Fraktionen und Polymeren bereitet Probleme. Die Thermische Analyse mit nachfolgender Photoionisierungsmassenspektrometrie ist hingegen gut geeignet, um diese anspruchsvollen Proben zu untersuchen. Komponenten werden verdampft oder durch Pyrolyse in kleinere Bruchstücke zersetzt, die dann mittels weicher, universeller oder selektiver Photoionisierung ionisiert und massenspektrometrisch detektiert werden. Neben der Evaluation der Methode, konnten so neue Erkenntnisse über Asphaltene, Foulingproben, Polyethylen und Polyethylenterephthalat gewonnen werden.Chemical analysis of heavy, highly viscous and poorly soluble fractions is still problematic. However, thermal analysis hyphenated to photo ionisation mass spectrometry is well suited for these challenging samples. Components either evaporate, or decompose into smaller products, which are then ionised by soft, universal or selective photo ionisation and detected by subsequent mass spectrometry. Besides the evaluation of the employed technique, new findings about asphaltenes, fouling samples, the branching of polyethylene and decomposition of polyethylene terephthalate are presented

Advanced ultrasonic ambient ionisation sources for mass spectrometry and microdroplet accelerated reactions

This PhD thesis presents two related projects, linked because both benefit from the use of a specific kind of ultrasonic nebulizer. The first project describes the development and subsequent application of a novel droplet-on-demand ionisation source which provides a solution to some of the limitations currently associated with performing mass calibration for mass spectrometry. After an initial development phase using a commercially available piezoelectric droplet-on-demand device, the system chosen for use was a Porous Ultrasonic Piezoelectric Plate (PUPP) device coupled to a conventional micro/nano-electrospray system. The PUPP system was used in the analysis of a highly complex organic matter sample, Suwannee River Fulvic Acid, and used encoded internal recalibration to generate high confidence automated peak assignment. Due to the droplet-on-demand nature of the PUPP device, calibrant could be introduced whenever needed during analysis, and the intensity of the calibrant peak relative to sample peaks could be adjusted through the system’s ability to modulate the volume of calibrant sprayed, in real time. Although the analysis of the samples using encoded internal recalibration showed no improvement in the peak assignment as expected, the workflow to get to the same stage is significantly simplified. The system is entirely automated, meaning that large batches of samples could be analysed, calibrated, and processed without the need for manual input by a user for each individual spectrum. Further beneficial applications of the PUPP ionisation source are also presented, including the capability to perform rapid analysis of samples, component confirmation analysis and real-time adduct modification. Additional tasks which were undertaken to support the development process of each project are presented, including the development of a 3D printed fused silica capillary grinding system to make custom electrospray needles and the software written to process the complex data generated for the ionisation source. Finally, recommendations for further development and other potential applications of the ionisation source are presented, which were beyond the scope of this project. The second project, aimed to use the PUPP system to perform chemical synthesis in microdroplets, by taking advantage of the significantly enhanced chemical reaction rates observed inside microdroplets reported in the literature. The Hydrazone reaction is shown to proceed offline using the PUPP system. However, the reaction is shown to preferentially form the E isomer when performed inside a microdroplet, whilst during bulk synthesis the Z isomer is preferentially formed. Evidence for this is given, including the subsequent photorelaxation of the E isomer to form the more stable Z isomer. Results indicated that the Pechmann condensation would be a new and suitable reaction which undergoes this reaction rate enhancement. However, this same success could not be achieved away from the mass spectrometer, and this was later discovered to be because of the difference in ionisation efficiencies of the reactants and products, which masked the true picture of the acceleration effect. Therefore, the decision was taken to shift the focus of the project towards establishing a robust screening method for microdroplet accelerated reactions which could be suitable for scale-up investigations, which is presented within this thesis

Effect of sample preparation on the characterization of crude oil and its complex fractions by high resolution mass spectrometry

Die Abhängigkeit der modernen Gesellschaft auf verfügbare Energie-Ressourcen wächst. Gleichzeitig, der rasante Anstieg der Preise auf den weltweiten Öl-Märkte in den letzten Jahren zeigt deutlich, dass eine bessere Ausnutzung der restlichen Quellen deutlich wichtiger wird. Trotz der eher teuren chemischen Aufarbeitungsmethoden, um saubere und nützliche Energieversorgung zu erzielen, wird die Aufarbeitung von unkonvetionellen Rohölen notwendig. Anderseites, haben höher siedenden Fraktionen von Standard Rohöle und schwere Rohöle erhöhten Konzentrationen von Heteroatomen, z. B. Schwefel-, Stickstoff-, Sauerstoff-oder Metall-Verbindungen. Viele dieser Verbindungen haben nachteilige Auswirkungen auf die Verarbeitung sowie auf die Leistung der Endprodukte. Die Optimierung der katalytischen Raffinierungsverfahren ist daher stark abhängig von der Qualität der chemischen Charakterisierung der Rohstoffe. In diesem Zusammenhang hat Fourier-Transform-Ionenzyklotronresonanz-Massenspektrometrie (FT-ICR MS) als analytische Methode bewiesen, dass die resultierenden Daten von ausreichender Genauigkeit und Auflösung sind. Dennoch, auch mit der letztlich hohen Auflösungsstärke des FT-ICR MS, beruht die genaue massenspektrometrische Analyse von Rohölkomponenten auf geeigneten Ionisationsmethoden und Trennverfahren. Die Rolle der Probenvorbereitung ist immens in dieser Hinsicht. Ohne Vereinfachung der komplexen Rohöl Probe ist es praktisch unmöglich, die Probe auch mit hochauflösender Massenspektrometrie einer einzelnen Messung zu analysieren. FT-MS Geräte arbeiten am besten, wenn eine kleinere Anzahl von Ionen bei jedem Transient verfügbar ist. Dies kann nicht in die Analyse von Rohöl Proben ohne Vereinfachung der Probe durchgeführt werden. Diese Studie basiert auf der Untersuchung der Probenvorbereitungsmethoden, die die Komplexität von Rohöl Proben vereinfacht und zur gleichen Zeit die Selektivität gegenüber Rohöl Klassen zeigt. Die Kombination dieser analytischen Ansätze mit höchster Auflösung der Massenspektrometrie gibt unverzichtbare Daten, die zur elementaren Zusammensetzung der Bestandteile der Probe führen. Dementsprechend werden statistische Informationen, die die Charakterisierung der Verbindungen ermöglicht, gewonnen. Vor allem, werden mit Hilfe hoch auflösende FT-MS Instrumente Extraktionsverfahren und Chromatographische Trennung in dieser Studie eingesetzt, damit komplexe Erdölproben analysiert und charakteriziert werden können.The dependency of the modern society on affordable energy resources, which fuels the economy and social development, is growing. The rapid rise of prices on the world’s oil markets in the last years clearly demonstrates that a better exploitation of the remaining supplies becomes distinctively more valuable. Despite the rather expensive chemical work-up procedures to yield clean and useful energy supplies, higher oil prices push the exploitation of non-conventional oils. Heavier crude oils and the higher boiling fractions of standard crude oils have thus become important resources to the expense of significantly elevated impurities levels, e.g., sulfur-, nitrogen-, oxygen- or metal-compounds. Many of these compounds have adverse effects on processing as well as on performance of the final products. The optimization of catalytic refinement processes is thus heavily dependent on the quality of the chemical characterization of the raw material. In this regard, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has proven to provide analytical data of sufficient accuracy and resolution. Nevertheless, even with the ultimately high resolving power of FT-ICR MS, the accurate mass spectrometric analysis of crude oil components relies on appropriate ionization and separation methods. The role of sample preparation is immense in this regard. Without simplification of the complex crude oil sample it is practically impossible to analyze the sample even with high resolution mass spectrometry by one-shot-measurement approach. FT-MS instruments operate best when smaller number of ions is present during each transient. This cannot be accomplished in the analysis of crude oil samples without simplification of the sample. This study is focusing on the investigation of sample preparation methods which simplify the complexity of crude oil samples and at the same time show selectivity towards crude oil classes. Combining these analytical approaches with ultrahigh resolution mass spectrometry gives indispensable data that lead to the elemental composition of the sample components. Accordingly, statistical information that allows characterization of the compounds is gained. Extraction methods and chromatographic separations are applied in this study to analyze and characterize complex crude oil samples using high resolution FT-MS instruments

41st Rocky Mountain Conference on Analytical Chemistry

Final program, abstracts, and information about the 41st annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 1-5, 1999

36th Rocky Mountain Conference on Analytical Chemistry

Program, abstracts, and information about the 36th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 31 - August 5, 1994

Environmental Molecular Sciences Laboratory 2007 Annual Report

This annual report provides details on the research conducted at the Environmental Molecular Sciences Laboratory in Fiscal Year 2007 and path forward for capability upgrades in Fiscal Year 2008

2003 research briefs : Materials and Process Sciences Center.

This report is the latest in a continuing series that highlights the recent technical accomplishments associated with the work being performed within the Materials and Process Sciences Center. Our research and development activities primarily address the materials-engineering needs of Sandia's Nuclear-Weapons (NW) program. In addition, we have significant efforts that support programs managed by the other laboratory business units. Our wide range of activities occurs within six thematic areas: Materials Aging and Reliability, Scientifically Engineered Materials, Materials Processing, Materials Characterization, Materials for Microsystems and Materials Modeling and Computational Simulation. We believe these highlights collectively demonstrate the importance that a strong materials-science base has on the ultimate success of the NW program and the overall DOE technology portfolio