Millions of tons of vacuum residues are produced in refineries every year and could be a potentially valuable resource for generating electricity and has possible application as heating and marine fuel. In this work, the polycyclic aromatic sulfur compounds (PASHs) from the aromatic fraction of vacuum residue before and after partial hydrodesulfurization (HDS) were derivatized by methylation to the methylsulfonium salts. Fourier transform ion cyclotron resonance mass spectrometry provided high-resolution data on these high-molecular-weight sulfur compounds. Compounds containing one and two S atoms were found to dominate, with masses up to ca. 900 Da. Classification according to hydrogen deficiency and the number of heteroatoms showed extensive series of homologues for double bond equivalents from 5 to 20. The sulfur-containing aromatics were separated using a palladium(II) complex as a liquid chromatographic phase into two compound groups: one containing compounds with an unconjugated thiophene ring and another with a condensed thiophene ring. This, combined with the mass spectrometry (MS) data, allows for the identification of several parent structures. Partial HDS removed primarily compounds with one S atom, whereas those with two S atoms were largely unaffected.

Over the years, ultrahigh resolution mass spectrometry has successfully illustrated the extreme complexity of crude oil and related solubility or polarity based fractions on a molecular level. However, the applied ionization technique greatly influences the outcome and may provide misleading information. In this work, we investigate the atmospheric pressure laser ionization (APLI) technique coupled with Fourier transform ion cyclotron resonance mass spectrometer to analyze the asphaltene fraction of a crude oil. These results were compared to data obtained by using other existing atmospheric pressure ionization methods. Furthermore elemental analysis and solid state NMR were used to obtain the bulk characteristics of the asphaltene sample. The results of the different ionization techniques were compared with the bulk properties in order to describe the potential discrimination effects of the ionization techniques that were observed. The results showed that APLI expands the range of the assigned molecules, while retaining information already observed with the generally used ion sources.

The first stages of solid-state formation from solution can be crucial in determining the properties of the resulting solids. We are trying to approach prenucleation reactions of silicates from an aqueous solution containing tetraalkylammoniumhydroxides (TAAOH) and tetraalkoxysilanes (TAOS) by analyzing hydrolysis and condensation using electrospray mass spectrometry (ESI MS). Time-resolved measurements were performed using different reactor systems to show the stepwise hydrolysis of the silanes and subsequent condensation of silicate monomers via oligomers to form larger units. We approached the precipitation point by varying the pH and the concentrations of the reactants. The results show the evolution of different silicate species occurring during condensation. No defined molecular entities were identified at pH values close to precipitation, which suggests that under the conditions used, solids are probably not formed from defined building blocks.

Through different windows: One major obstacle in energy research is the complexity and variety of compounds present in crude oil. A study of different ionization methods for mass spectrometry shows that the mass spectrum very strongly depends on which method is used.

In this study, a heavy crude oil sample was separated on the basis of solubility and polarity, resulting in saturates, aromatics, resins, and asphaltenes (SARA) fractions. The fractions were analyzed by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) coupled to atmospheric pressure laser ionization (APLI). On the basis of the APLI–FT-ICR MS results, the molecular formulas and their corresponding aromaticity were compared to the bulk crude oil. The maltenes showed almost identical compound class distribution to the bulk sample, while the subfractions of the maltenes denoted unique distributions in compound classes and aromaticity. The aromaticity distributions of the fractions were in good agreement with expectations; however, the resins fraction showed higher aromaticity than the aromatics fraction. The potential of the SARA fractionation method as a sample-simplification tool that allows for a reduction of components present during the measurements was also demonstrated using APLI–FT-ICR MS

Inhaltsangabe: Eine große Hürde für eine optimale Energiegewinnung aus Erdöl ist die Komplexität und Vielfalt der darin enthaltenen Verbindungen. Eine Untersuchung verschiedener Ionisierungsmethoden für die Massenspektrometrie ergibt, dass das Massenspektrum einer Erdölprobe stark von der jeweils verwendeten Methode abhängt.

Crude oil analysis has long been an inspiration for the development of analytical techniques. Especially mass spectrometry has flourished as a result of the challenge these extremely complex problems offer. Here an overview of different analytical methods is presented that shows different ways to analyze volatile and nonvolatile crude oil components. Focus has been placed on the use of mass spectrometry and especially the new developments that have been introduced using the emerging technique of Fourier transform ion cyclotron resonance mass spectrometry. These studies are examples of how far the development of analytical methods has come for the task of studying such complex problems.

The early stages of crystal formation are among the most elusive problems in zeolite science and possibly in all of solidstate chemistry. [1][2][3][4] This is largely because the nucleation step or nucleation phase causes major problems in experimental investigations, as the size of the aggregates most probably involved lies between small molecules and the extended solid.[5] Often-used techniques are NMR spectroscopy, diffraction, scattering with different types of radiation, transmission electron microscopy (TEM), and X-ray absorption spectroscopy. Each of these techniques reveals another "part of the puzzle" of the formation of a crystal from a precursor solution. In previous works we introduced electrospray ionization mass spectrometry (ESI-MS) as a suitable technique to investigate the oligomer distribution and its temporal development in prenucleating silicate solutions.[6-8] Herein, we extend this work to solution conditions, from which zeolite nucleation and crystallization occurs during the MS experiments. The results suggest that it is not single silicate oligomers that play a special role in zeolite formation, but that all silicate species present in solution act as a reservoir for the formation of a solid, finally crystalline phase.We concentrated on the all-silica versions of ZSM-5 (MFI topology) and ZSM-11 (MEL topology), silicalite-1 and silicalite-2, respectively, which can both be crystallized from clear solutions. The formation of specific structures is directed by organic additives, tetrapropylammonium (TPA) in the case of the MFI structure and tetrabutylammonium (TBA) for MEL. It is unclear at which stage in the solid-state formation process the template ions exert their structure-directing effect and how this effect is actually brought about on a molecular level. There is strong evidence that crystalline structures are formed directly from colloidal particles that serve as a nutrient [9][10][11] -at least for some cases including silicalite-1 and silicalite-2. Other models involve the existence of small particles (below 10 nm) as crucial species in the formation of high-silica zeolites, although the further course of the reaction is again disputed. Aggregation of these particles to form crystals is the main aspect in some models, [12][13][14] but it has also been suggested that crystal nucleation and growth proceeds through the addition of monomers to smaller clusters. [15,16] Among the models that involve a particle-aggregation mechanism, there is disagreement whether the small entities that lead to zeolite formation have the same molecular structure and are essentially already small fragments of the zeolite framework, or whether they are only uniform in size and shape but disordered on the molecular level. The most specific model suggests one majority silicate species to be present in solution, which already exhibits the crystal structure of the final zeolite.[14] The other models would involve a rather broad variety of silicate species. [12,13] The results obtained with 29 Si NMR spectrosc...