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With the depletion of conventional resources, heavier and more sulfur-rich crude oils come into the focus of interest. However, the utilization of such feedstocks is extremely undesirable since their high sulfur content causes corrosion fouling, catalyst poisoning, and emissions of toxic pollutants into the atmosphere. As known catalyst poisoners, sulfur-containing compounds are also suspected to play an important role in crude oil fouling, that is, the formation of undesired solid deposits. To overcome these problems, insightful knowledge on the chemical composition of the sulfur-containing compounds on a molecular level and their behavior is necessary. Here, fouling reactions of a gas condensate were simulated in the laboratory under atmospheric and inert conditions, with special focus on sulfur-containing compounds, and the resulting mixtures were analyzed by using sophisticated analytical methods such as ultrahigh-resolution mass spectrometry and electron microscopy. The results indicate that sulfur-containing compounds decompose at elevated temperatures, partly by a radical-induced mechanism. Furthermore, the resulting intermediates show a limited stability in the presence of oxygen.
Aikaterini Kondyli; Wolfgang Schrader. Study of Crude Oil Fouling from Sulfur-Containing Compounds Using High-Resolution Mass Spectrometry. Energy & Fuels 2021, 35, 13022 -13029.
AMA StyleAikaterini Kondyli, Wolfgang Schrader. Study of Crude Oil Fouling from Sulfur-Containing Compounds Using High-Resolution Mass Spectrometry. Energy & Fuels. 2021; 35 (16):13022-13029.
Chicago/Turabian StyleAikaterini Kondyli; Wolfgang Schrader. 2021. "Study of Crude Oil Fouling from Sulfur-Containing Compounds Using High-Resolution Mass Spectrometry." Energy & Fuels 35, no. 16: 13022-13029.
Over the last 40 years, soils contaminated with polycyclic aromatic hydrocarbons (PAH) were monitored according to a list of 16 PAH, established by the U.S. Environmental Protection Agency (EPA). This, however, is underestimating the danger to the environment and humanity because other high molecular weight PAHs, heterocycles (PAXH, X = N, O, S) and alkylated derivatives can also occur at the contaminated site. Here, a new non-targeted approach of highly contaminated soil (64.5 ± 9.5 g kg−1 solvent extractable organics from the German Ruhrgebiet) is introduced, where ultrahigh resolution mass spectrometry is combined with multiple ionization methods to get a better overview of anthropogenic contamination at a former industrial site. In total, 21,958 elemental compositions were assigned for positive and negative mode measurements. The approach is strongly increasing the amount of data that can be obtained from a single contaminated soil, making an assessment of the real environmental risk possible. In addition to highly aromatized and (alkylated) high molecular weight PAH, other PAXH especially basic and neutral PANH with very high aromaticity were also detected. This shows that while regulations and routine analysis are still stuck in the 1960 s, modern analytical methods are present in the 21st century.
Ruoji Luo; Wolfgang Schrader. Getting a better overview of a highly PAH contaminated soil: A non-targeted approach assessing the real environmental contamination. Journal of Hazardous Materials 2021, 418, 126352 .
AMA StyleRuoji Luo, Wolfgang Schrader. Getting a better overview of a highly PAH contaminated soil: A non-targeted approach assessing the real environmental contamination. Journal of Hazardous Materials. 2021; 418 ():126352.
Chicago/Turabian StyleRuoji Luo; Wolfgang Schrader. 2021. "Getting a better overview of a highly PAH contaminated soil: A non-targeted approach assessing the real environmental contamination." Journal of Hazardous Materials 418, no. : 126352.
Detailed molecular analysis of complex mixtures such as crude oil and its fractions has been successfully covered by a number of groups during the past two decades. On the other side, the most glaring need is some type of method that allows quantitative analysis of a single class, compound species, or even individual compounds. Here, the problem is being complicated by the complexity of the sample and the need for individual response factors necessary for the analysis of single compounds in almost all analytical methods. This can be circumvented by using a method with uniform response like inductively coupled plasma-mass spectrometry. Sulfur is one of the most important heteroelements present in crude oil and its products due to stringent regulations. Quantification of sulfur by means of mass spectrometry has always been a challenging task. Here, we present the combination of a sulfur-selective chromatographic separation of crude oil and its fractions on a Pd-coated stationary phase with two-dimensional detection. Qualitative analysis by ultrahigh-resolution Orbitrap mass spectrometry allows a detailed understanding of individual compositions after chromatographic separation, while the quantitative data from inductively coupled plasma tandem mass spectrometry details the quantities of each part of the chromatogram. The combination of the results from both methods allows assigning three different types of sulfur species and their quantitative determination in extremely complex heavy crude oil fractions.
Alessandro Vetere; Daniel Pröfrock; Wolfgang Schrader. Qualitative and Quantitative Evaluation of Sulfur-Containing Compound Types in Heavy Crude Oil and Its Fractions. Energy & Fuels 2021, 35, 8723 -8732.
AMA StyleAlessandro Vetere, Daniel Pröfrock, Wolfgang Schrader. Qualitative and Quantitative Evaluation of Sulfur-Containing Compound Types in Heavy Crude Oil and Its Fractions. Energy & Fuels. 2021; 35 (10):8723-8732.
Chicago/Turabian StyleAlessandro Vetere; Daniel Pröfrock; Wolfgang Schrader. 2021. "Qualitative and Quantitative Evaluation of Sulfur-Containing Compound Types in Heavy Crude Oil and Its Fractions." Energy & Fuels 35, no. 10: 8723-8732.
Biofuel produced from biomass pyrolysis is a good example of a highly complex mixture. Detailed understanding of its composition is a prerequisite for optimizing transformation processes and further upgrading conditions. The major challenge in understanding the composition of biofuel derived from biomass is the wide range of compounds with high diversity in polarity and abundance that can be present. In this work, a comprehensive analysis using mass spectrometry is reported. Different operation conditions are studied by utilizing multiple ionization methods (positive mode atmospheric pressure photo ionization (APPI), atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) and negative mode ESI) and applying different resolving power set-ups (120 k, 240 k, 480 k and 960 k) and scan techniques (full scan and spectral stitching method) to study the complexity of a pyrolysis biofuel. Using a mass resolution of 960 k and the spectral stitching scan technique gives a total of 21,703 assigned compositions for one ionization technique alone. The number of total compositions is significantly expanded by the combination of different ionization methods.
Yun Xu; Wolfgang Schrader. Studying the Complexity of Biomass Derived Biofuels. Energies 2021, 14, 2032 .
AMA StyleYun Xu, Wolfgang Schrader. Studying the Complexity of Biomass Derived Biofuels. Energies. 2021; 14 (8):2032.
Chicago/Turabian StyleYun Xu; Wolfgang Schrader. 2021. "Studying the Complexity of Biomass Derived Biofuels." Energies 14, no. 8: 2032.
The complexity of crude oil samples has hindered its detailed analysis and understanding. Although modern analytical methods such as ultrahigh-resolution mass spectrometry have opened the understanding of the molecular composition, discrimination due to the complexity is sabotaging a better understanding. Therefore, the SARA fractionation has been used to reduce complexity by adding a fractionation step prior to analysis. However, our studies indicate that the conventional combinations of solvents used for SARA fractionation are inefficient for the elution of heavier fractions of crude oil from the alumina stationary phase. Adding an additional step to the conventional SARA scheme provides a second resin fraction using ethyl acetate as an additional mobile phase and provides a new material that has not yet been reported. For a better understanding of the differences between both resin fractions, detailed studies have been carried out utilizing ultrahigh-resolution mass spectrometry with different types of ionization methods, one of the best scenarios to reduce discrimination and suppression effects.
Jandyson M. Santos; Alessandro Vetere; Alberto Wisniewski; Marcos N. Eberlin; Wolfgang Schrader. Modified SARA Method to Unravel the Complexity of Resin Fraction(s) in Crude Oil. Energy & Fuels 2020, 34, 16006 -16013.
AMA StyleJandyson M. Santos, Alessandro Vetere, Alberto Wisniewski, Marcos N. Eberlin, Wolfgang Schrader. Modified SARA Method to Unravel the Complexity of Resin Fraction(s) in Crude Oil. Energy & Fuels. 2020; 34 (12):16006-16013.
Chicago/Turabian StyleJandyson M. Santos; Alessandro Vetere; Alberto Wisniewski; Marcos N. Eberlin; Wolfgang Schrader. 2020. "Modified SARA Method to Unravel the Complexity of Resin Fraction(s) in Crude Oil." Energy & Fuels 34, no. 12: 16006-16013.
“Fouling”, the unwanted deposition of solids, causes significant operational difficulties in petroleum producing and pro-cessing industries and is considered a billion dollar problem. There are two routes of petroleum fouling: physical fouling, where material of low solubility precipitates, and chemical fouling, where a chemical reaction produces insoluble material, often on the surface of heat exchangers. By implementing laboratory-scale experimental simulations of the industrial pro-cess using a petroleum derived light crude oil fraction, it is shown that chemical fouling proceeds via multi-step pathways involving dehydrogenation and radical formation reactions on PAHs, resulting in the formation of carbonaceous deposits.
Aikaterini Kondyli; Wolfgang Schrader. Understanding “Fouling” in Extremely Complex Petroleum Mixtures. ACS Applied Energy Materials 2020, 3, 7251 -7256.
AMA StyleAikaterini Kondyli, Wolfgang Schrader. Understanding “Fouling” in Extremely Complex Petroleum Mixtures. ACS Applied Energy Materials. 2020; 3 (8):7251-7256.
Chicago/Turabian StyleAikaterini Kondyli; Wolfgang Schrader. 2020. "Understanding “Fouling” in Extremely Complex Petroleum Mixtures." ACS Applied Energy Materials 3, no. 8: 7251-7256.
Buckyballs (Fullerenes) were first reported over 30 years ago, but still little is known regarding their natural occurrence, as they were only found at sites of high energy incidents, such as lightning strikes or meteor impacts but not reported in low energy materials like fossil fuels. Here, using ultrahigh‐resolution mass spectrometry, a wide range of Fullerenes from C 20 to C 114 was detected in an asphaltene fraction of a heavy crude oil, together with their building blocks of C 10n H 10 ‐stoichiometry. High level DLPNO‐CCSD(T) calculations corroborate their stability as spherical and hemi‐spherical species. Interestingly, the maximum intensity of the Fullerenes was found at C 40 instead of the major Fullerene C 60 . Hence, experimental evidence supported by calculations show the existence of not only buckyballs, but also buckybowls as 3‐dimensional polyaromatic compounds in fossil material.
Zahra Farmani; Alessandro Vetere; Corentin Poidevin; Alexander A. Auer; Wolfgang Schrader. Studying Natural Buckyballs and Buckybowls in Fossil Materials. Angewandte Chemie 2020, 132, 15118 -15123.
AMA StyleZahra Farmani, Alessandro Vetere, Corentin Poidevin, Alexander A. Auer, Wolfgang Schrader. Studying Natural Buckyballs and Buckybowls in Fossil Materials. Angewandte Chemie. 2020; 132 (35):15118-15123.
Chicago/Turabian StyleZahra Farmani; Alessandro Vetere; Corentin Poidevin; Alexander A. Auer; Wolfgang Schrader. 2020. "Studying Natural Buckyballs and Buckybowls in Fossil Materials." Angewandte Chemie 132, no. 35: 15118-15123.
Buckyballs (Fullerenes) were first reported over 30 years ago, but still little is known regarding their natural occurrence, as they were only found at sites of high energy incidents, such as lightning strikes or meteor impacts but not reported in low energy materials like fossil fuels. Here, using ultrahigh‐resolution mass spectrometry, a wide range of Fullerenes from C 20 to C 114 was detected in an asphaltene fraction of a heavy crude oil, together with their building blocks of C 10n H 10 ‐stoichiometry. High level DLPNO‐CCSD(T) calculations corroborate their stability as spherical and hemi‐spherical species. Interestingly, the maximum intensity of the Fullerenes was found at C 40 instead of the major Fullerene C 60 . Hence, experimental evidence supported by calculations show the existence of not only buckyballs, but also buckybowls as 3‐dimensional polyaromatic compounds in fossil material.
Zahra Farmani; Alessandro Vetere; Corentin Poidevin; Alexander A. Auer; Wolfgang Schrader. Studying Natural Buckyballs and Buckybowls in Fossil Materials. Angewandte Chemie International Edition 2020, 59, 15008 -15013.
AMA StyleZahra Farmani, Alessandro Vetere, Corentin Poidevin, Alexander A. Auer, Wolfgang Schrader. Studying Natural Buckyballs and Buckybowls in Fossil Materials. Angewandte Chemie International Edition. 2020; 59 (35):15008-15013.
Chicago/Turabian StyleZahra Farmani; Alessandro Vetere; Corentin Poidevin; Alexander A. Auer; Wolfgang Schrader. 2020. "Studying Natural Buckyballs and Buckybowls in Fossil Materials." Angewandte Chemie International Edition 59, no. 35: 15008-15013.
A non-targeted method for analyzing petroleum hydrocarbons in soil was established by extracting a wide range of PAC compounds using a model system. Here, sand was spiked with a heavy crude oil, which simulated a hydrocarbon contaminated soil of low soil organic matter (SOM). Soxhlet and supercritical fluid extraction (SFE) was optimized for PAXHs analysis in soil. A concept of using multidimensional ionization for ultrahigh resolution mass spectrometry was employed for detection using electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photo ionization (APPI) for the analysis of polycyclic aromatic hydrocarbons (PAHs) and polycyclic aromatic heterocycles. Fourier transform mass spectrometry (FT-MS) with its ultrahigh mass resolution and high mass accuracy enables an unambiguous assignment of the detected ions obtained from different ionization methods, which provides a secure and comprehensive view of contaminants in soil on a molecular level. Over 95% of the spiked crude oil could be recovered by Soxhlet extraction using toluene, dichloromethane and acetone:n-hexane (1:1, v:v). In comparison, when using SFE with supercritical CO2 the recovery was only about 50% but showed more polar compounds. Detailed analyses showed that besides 16 PAHs, a wide range with more than 10,000 PAXHs could also be successfully extracted.
Ruoji Luo; Wolfgang Schrader. Development of a Non-Targeted Method to Study Petroleum Polyaromatic Hydrocarbons in Soil by Ultrahigh Resolution Mass Spectrometry Using Multiple Ionization Methods. Polycyclic Aromatic Compounds 2020, 1 -16.
AMA StyleRuoji Luo, Wolfgang Schrader. Development of a Non-Targeted Method to Study Petroleum Polyaromatic Hydrocarbons in Soil by Ultrahigh Resolution Mass Spectrometry Using Multiple Ionization Methods. Polycyclic Aromatic Compounds. 2020; ():1-16.
Chicago/Turabian StyleRuoji Luo; Wolfgang Schrader. 2020. "Development of a Non-Targeted Method to Study Petroleum Polyaromatic Hydrocarbons in Soil by Ultrahigh Resolution Mass Spectrometry Using Multiple Ionization Methods." Polycyclic Aromatic Compounds , no. : 1-16.
RATIONALE Characterization of complex samples remains a challenging task due to the high number of compounds present. Matrix effects, ion discrimination and suppression are limiting factors, which forces the use of different methods for the same sample to gain a broad understanding of complex mixtures. METHODS Various ionization techniques such as ESI, APPI and APCI have been used in various problems for complex mixture analysis. Especially demanding is the analysis of energy related hydrocarbon mixtures, such as crude oil. Here, the different ionization sources alone and in combination with each other have been used on an ultrahigh resolution Orbitrap mass spectrometer to study a light crude oil. RESULTS Despite the great variety of the available ionization sources, there is no single technique, which can fully characterize the crude oil. Each ionization technique shows a selectivity towards specific types of compounds. While ESI is the method of choice for the detection of polar compounds, APPI and APCI favors the detection of non‐polar and low‐to‐medium polar compounds respectively. The combination of ESI/APPI favors hydrocarbons and oxygen containing species. CONCLUSIONS Combining different ionization methods can be used as an alternative in order to gain more information about compounds present in a complex mixture although a combination of different ion sources could enhance suppression effects.
Aikaterini Kondyli; Wolfgang Schrader. Evaluation of the combination of different atmospheric pressure ionization sources for the analysis of extremely complex mixtures. Rapid Communications in Mass Spectrometry 2019, 34, e8676 .
AMA StyleAikaterini Kondyli, Wolfgang Schrader. Evaluation of the combination of different atmospheric pressure ionization sources for the analysis of extremely complex mixtures. Rapid Communications in Mass Spectrometry. 2019; 34 (8):e8676.
Chicago/Turabian StyleAikaterini Kondyli; Wolfgang Schrader. 2019. "Evaluation of the combination of different atmospheric pressure ionization sources for the analysis of extremely complex mixtures." Rapid Communications in Mass Spectrometry 34, no. 8: e8676.
SARA (Saturates, Aromatics, Resins, Asphaltenes) fractionation is a common simplification technique used for decades in petrochemical analysis. A large number of studies are dealing with the different fractions, but overall, the saturate fraction is strongly neglected. Of the very few available studies on the saturates fraction, almost all have been performed using gas chromatographic (GC) techniques. This discriminates the results of the saturate fraction especially since non-volatile, high molecular weight and polar constituents are mostly excluded. Here, for the first time, saturate fractions of different crude oils from different origins are analyzed using direct infusion ultrahigh resolution mass spectrometry (UHRMS), to study the compositions on a molecular level. Electrospray (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) are used in positive mode. The observed results show the presence of different heteroatom containing classes, with different chemical identities (i.e., presence of thiophenes, mercaptans and cyclic-sulfides in case of S-containing compounds). These results show the high affinity of some specific compounds towards different ionization techniques. Finally, the saturate fraction is shown to include much more than only volatile, saturated and aliphatic compounds. The detected compounds in this fraction present a very wide variety, not only in terms of their carbon atoms per molecule and their aromaticity, but also with regard to their functional groups and structural arrangements.
Zahra Farmani; Wolfgang Schrader. A Detailed Look at the Saturate Fractions of Different Crude Oils Using Direct Analysis by Ultrahigh Resolution Mass Spectrometry (UHRMS). Energies 2019, 12, 3455 .
AMA StyleZahra Farmani, Wolfgang Schrader. A Detailed Look at the Saturate Fractions of Different Crude Oils Using Direct Analysis by Ultrahigh Resolution Mass Spectrometry (UHRMS). Energies. 2019; 12 (18):3455.
Chicago/Turabian StyleZahra Farmani; Wolfgang Schrader. 2019. "A Detailed Look at the Saturate Fractions of Different Crude Oils Using Direct Analysis by Ultrahigh Resolution Mass Spectrometry (UHRMS)." Energies 12, no. 18: 3455.
Rationale 1Structural characterization of individual compounds in very complex mixtures is difficult to achieve. One important step in structural elucidation is understanding the mass spectrometric fragmentation mechanisms of the compounds present in such mixtures. Here, different individual compounds presumed to be present in a complex crude oil mixture have been synthesized and structurally characterized by MS/MS studies. Methods Model compounds with different aromatic cores and various substitutents were synthesized. Major effort has been put into producing isomerically pure compounds to better understand the fragmentation pattern. Each synthesized compound has been subjected to MSn studies using either a triple quadrupole MS or a linear ion trap MS with electrospray or atmospheric pressure photo ionization. The results are used to analyze individual compounds from a complex vacuum gas oil (VGO). Results The synthesized compounds and a chromatographically simplified vacuum gas oil were used for structural analysis. The major fragmentation mechanism is the benzylic cleavage of the aliphatic side chains. Each side chain can be separately removed from the aromatic core by using MSn methods. At the end of a series of fragmentations, the base aromatic core structure remains and can be chararcterized. Conclusion By defining the fragmentation mechanism in complex oil samples it was possible to structurally characterize individual compounds present in a chromatographically simplified VGO. The compounds consist of an aromatic core with aliphatic side chains. Cleavage of all side chains can be achieved by MSn measurements, allowing characterization of the remaining core structure.
Alessandro Vetere; M. Wasim Alachraf; Saroj K. Panda; Jan T. Andersson; Wolfgang Schrader. Studying the fragmentation mechanism of selected components present in crude oil by collision-induced dissociation mass spectrometry. Rapid Communications in Mass Spectrometry 2018, 32, 2141 -2151.
AMA StyleAlessandro Vetere, M. Wasim Alachraf, Saroj K. Panda, Jan T. Andersson, Wolfgang Schrader. Studying the fragmentation mechanism of selected components present in crude oil by collision-induced dissociation mass spectrometry. Rapid Communications in Mass Spectrometry. 2018; 32 (24):2141-2151.
Chicago/Turabian StyleAlessandro Vetere; M. Wasim Alachraf; Saroj K. Panda; Jan T. Andersson; Wolfgang Schrader. 2018. "Studying the fragmentation mechanism of selected components present in crude oil by collision-induced dissociation mass spectrometry." Rapid Communications in Mass Spectrometry 32, no. 24: 2141-2151.
The continuous development in analytical instrumentation has brought the newly developed Orbitrap based GC‐MS instrument into the forefront for the analysis of complex mixtures such as crude oil. Traditional instrumentation usually requires a choice to be made between mass resolving power or an efficient chromatographic separation which ideally enables the distinction of structural isomers which is not possible by mass spectrometry alone. Now, these features can be combined, thus enabling a deeper understanding of the constituents of volatile samples on a molecular level. Although electron ionization is the most popular ionization method employed in GC/MS analysis, the need for softer ionization methods has led to the utilization of atmospheric pressure ionization sources. The last arrival to this family is the atmospheric pressure photoionization (APPI), which was originally developed for (LC)MS. With a newly developed commercial GC‐APPI interface it is possible to extend the characterization of unknown compounds. Here, first results about the capabilities of the GC/MS instrument under high or low energy EI or APPI are reported on a volatile gas condensate. The use of different ionization energies helps matching the low abundant molecular ions to the structurally important fragment ions. A broad range of compounds from polar to medium polar were successfully detected and complementary information regarding the analyte was obtained.
Aikaterini Kondyli; Wolfgang Schrader. High-resolution GC/MS studies of a light crude oil fraction. Journal of Mass Spectrometry 2018, 54, 47 -54.
AMA StyleAikaterini Kondyli, Wolfgang Schrader. High-resolution GC/MS studies of a light crude oil fraction. Journal of Mass Spectrometry. 2018; 54 (1):47-54.
Chicago/Turabian StyleAikaterini Kondyli; Wolfgang Schrader. 2018. "High-resolution GC/MS studies of a light crude oil fraction." Journal of Mass Spectrometry 54, no. 1: 47-54.
The combination of fractionation methods for crude oils, such as saturate, aromatic, resin and asphaltene (SARA) fractionation, in combination with analysis by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has been used for reducing the complexity and improving the characterization of crude oils. We have used the FT-ICR MS techniques in conjunction with electrospray ionization (ESI(±)) and atmospheric pressure photoionization (APPI(+)) to find trends between MS data of SARA fractions of crude oils with different American Petroleum Institute (API) gravities from the Sergipe-Alagoas basin (Brazil), focusing on the resin and asphaltene fractions. For the first time, an adaptation of the SARA fractionation has been performed to obtain a second resin fraction, which presented compounds with an intermediate aromaticity level between the first resins and asphaltene fraction. Both the first and second resin and the asphaltene fractions were studied on a molecular level using multiple ionization techniques and FT-ICR MS to find a direct relationship between the API gravities of a heavy, medium and light crude oil. For the FT-ICR MS data and the API gravities an aromaticity tendency was found. The data show that the use of SARA fractionation with FT-ICR MS offers a tool for comprehensive characterization of individual fractions and selective chemical characterization of the components in crude oils.
Jandyson M. Santos; Alessandro Vetere; Jr. Alberto Wisniewski; Marcos N. Eberlin; Wolfgang Schrader. Comparing Crude Oils with Different API Gravities on a Molecular Level Using Mass Spectrometric Analysis. Part 2: Resins and Asphaltenes. Energies 2018, 11, 2767 .
AMA StyleJandyson M. Santos, Alessandro Vetere, Jr. Alberto Wisniewski, Marcos N. Eberlin, Wolfgang Schrader. Comparing Crude Oils with Different API Gravities on a Molecular Level Using Mass Spectrometric Analysis. Part 2: Resins and Asphaltenes. Energies. 2018; 11 (10):2767.
Chicago/Turabian StyleJandyson M. Santos; Alessandro Vetere; Jr. Alberto Wisniewski; Marcos N. Eberlin; Wolfgang Schrader. 2018. "Comparing Crude Oils with Different API Gravities on a Molecular Level Using Mass Spectrometric Analysis. Part 2: Resins and Asphaltenes." Energies 11, no. 10: 2767.
Different ionization techniques based on different principles have been applied for the direct mass spectrometric (MS) analysis of crude oils providing composition profiles. Such profiles have been used to infer a number of crude oil properties. We have tested the ability of two major atmospheric pressure ionization techniques, electrospray ionization (ESI(±)) and atmospheric pressure photoionization (APPI(+)), in conjunction with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The ultrahigh resolution and accuracy measurements of FT-ICR MS allow for the correlation of mass spectrometric (MS) data with crude oil American Petroleum Institute (API) gravities, which is a major quality parameter used to guide crude oil refining, and represents a value of the density of a crude oil. The double bond equivalent (DBE) distribution as a function of the classes of constituents, as well as the carbon numbers as measured by the carbon number distributions, were examined to correlate the API gravities of heavy, medium, and light crude oils with molecular FT-ICR MS data. An aromaticity tendency was found to directly correlate the FT-ICR MS data with API gravities, regardless of the ionization technique used. This means that an analysis on the molecular level can explain the differences between a heavy and a light crude oil on the basis of the aromaticity of the compounds in different classes. This tendency of FT-ICR MS with all three techniques, namely, ESI(+), ESI(−), and APPI(+), indicates that the molecular composition of the constituents of crude oils is directly associated with API gravity.
Jandyson M. Santos; Alberto Wisniewski Jr.; Marcos N. Eberlin; Wolfgang Schrader. Comparing Crude Oils with Different API Gravities on a Molecular Level Using Mass Spectrometric Analysis. Part 1: Whole Crude Oil. Energies 2018, 11, 2766 .
AMA StyleJandyson M. Santos, Alberto Wisniewski Jr., Marcos N. Eberlin, Wolfgang Schrader. Comparing Crude Oils with Different API Gravities on a Molecular Level Using Mass Spectrometric Analysis. Part 1: Whole Crude Oil. Energies. 2018; 11 (10):2766.
Chicago/Turabian StyleJandyson M. Santos; Alberto Wisniewski Jr.; Marcos N. Eberlin; Wolfgang Schrader. 2018. "Comparing Crude Oils with Different API Gravities on a Molecular Level Using Mass Spectrometric Analysis. Part 1: Whole Crude Oil." Energies 11, no. 10: 2766.
The asphaltene fraction is the heaviest part of a crude oil and is obtained as the fraction which contains compounds that are not soluble in paraffinic solvents such as n-heptane. Due to the limited solubility the use of separation methods is strongly reduced to methods that include solvents that dissolve asphaltenes. Here, the direct coupling of size exclusion chromatography with ultrahigh resolution mass spectrometry to investigate the separation of asphaltenes is accomplished. Different mobile phase systems have been investigated using THF and different mixtures of chloroform and toluene to optimize the separation conditions. Due to the separation the complexity of the asphaltene sample can be reduced, therefore mass spectra with increased information depth can be obtained due to the smaller amount of interacting species. Additionally, correlations can be proposed between molecular mass and structural characteristics of highly condensed aromatic molecules: compounds having both aromatic core and long aliphatic chains with higher masses were detected earlier and the smaller ones containing mostly highly aromatic structures and only a low amount of short alkyl chains (with the same DBE values) have stronger retention. Different experimental conditions such as stationary phase and mobile phase of asphaltene separation with size exclusion chromatography are investigated.
Lilla Molnárné Guricza; Wolfgang Schrader. Optimized asphaltene separation by online coupling of size exclusion chromatography and ultrahigh resolution mass spectrometry. Fuel 2018, 215, 631 -637.
AMA StyleLilla Molnárné Guricza, Wolfgang Schrader. Optimized asphaltene separation by online coupling of size exclusion chromatography and ultrahigh resolution mass spectrometry. Fuel. 2018; 215 ():631-637.
Chicago/Turabian StyleLilla Molnárné Guricza; Wolfgang Schrader. 2018. "Optimized asphaltene separation by online coupling of size exclusion chromatography and ultrahigh resolution mass spectrometry." Fuel 215, no. : 631-637.
Die Verbrennung schwefelhaltiger Treibstoffe führt zu Umweltproblemen. Deshalb gelten strenge Bestimmungen, die den Schwefelgehalt von Treibstoffen auf wenige ppm begrenzen. Angesichts der Verringerung schwefelarmer Erdölquellen werden immer größere technische Anstrengungen nötig, diese Bestimmungen einzuhalten. Die Entschwefelung ist ein kritischer Teil im Rahmen des Raffinierungsprozesses, welcher jedoch nicht vollständig verläuft und der angesichts der Komplexität der vielen verschiedenen Stoffklassen auch nicht völlig verstanden ist. Wir stellen hier einen neuen Ansatz vor, um drei Klassen von Schwefelverbindungen in Erdöl mithilfe einer LC-Trennung und Detektion per ICP-MS/MS zu quantifizieren. Diese neue, einfache Methode sollte helfen, den Anteil schwer entschwefelbarer Verbindungen abzuschätzen und so den Entschwefelungsprozess zu optimieren.
Alessandro Vetere; Daniel Pröfrock; Wolfgang Schrader. Quantitative und qualitative Analyse dreier Klassen von Schwefelverbindungen in Erdöl. Angewandte Chemie 2017, 129, 11073 -11077.
AMA StyleAlessandro Vetere, Daniel Pröfrock, Wolfgang Schrader. Quantitative und qualitative Analyse dreier Klassen von Schwefelverbindungen in Erdöl. Angewandte Chemie. 2017; 129 (36):11073-11077.
Chicago/Turabian StyleAlessandro Vetere; Daniel Pröfrock; Wolfgang Schrader. 2017. "Quantitative und qualitative Analyse dreier Klassen von Schwefelverbindungen in Erdöl." Angewandte Chemie 129, no. 36: 11073-11077.
Fossil fuels are one of the most important energy resources until new sustainable materials become available. To optimize the upgrading processes of these materials characterization of the remaining heavy materials is of great importance. Asphaltenes are the most difficult fraction of crude oil to process due to the limited number of solvents in which they can be dissolved. Chromatographic separation methods need to consider the difficulties associated with these limitations. Size-exclusion chromatography (SEC) in combination with Fourier transform Orbitrap mass spectrometry (MS) combines the capabilities of ultrahigh resolution and very high mass accuracy with a separation method that allows using solvents as mobile phase for asphaltene separation. A chromatographic method was developed that shows the separation of asphaltenes according to their molecular mass. A simplification of the samples was achieved by reducing the number of compounds present in a single spectrum compared to infusion data. Direct detection by mass spectrometry additionally allows a distinction of different isomers present in the complex samples. Direct coupling of SEC with ultrahigh-resolution mass spectrometry allows the study of the most difficult to analyze fraction of crude oil, the asphaltene fraction. Separation reduces the complexity of individual spectra and, therefore, also reduces suppression and discrimination effects. The separation of structural isomers which cannot be characterized by MS alone gives an added dimension to the analysis of asphaltenes. Copyright © 2016 John Wiley & Sons, Ltd.
Thierry Ghislain; Lilla Molnárné Guricza; Wolfgang Schrader. Characterization of crude oil asphaltenes by coupling size-exclusion chromatography directly to an ultrahigh-resolution mass spectrometer. Rapid Communications in Mass Spectrometry 2017, 31, 495 -502.
AMA StyleThierry Ghislain, Lilla Molnárné Guricza, Wolfgang Schrader. Characterization of crude oil asphaltenes by coupling size-exclusion chromatography directly to an ultrahigh-resolution mass spectrometer. Rapid Communications in Mass Spectrometry. 2017; 31 (6):495-502.
Chicago/Turabian StyleThierry Ghislain; Lilla Molnárné Guricza; Wolfgang Schrader. 2017. "Characterization of crude oil asphaltenes by coupling size-exclusion chromatography directly to an ultrahigh-resolution mass spectrometer." Rapid Communications in Mass Spectrometry 31, no. 6: 495-502.
Simplification of highly complex mixtures such as crude oil by using chromatographic methods makes it possible to get more detailed information about the composition of the analyte. Separation by argentation chromatography can be achieved based on the interaction of different strength between the silver ions (Ag(+)) immobilized through a spacer on the silica gel surface and the π-bonds of the analytes. Heavy crude oils contain compounds with a high number of heteroatoms (N, O, S) and a high degree of unsaturation thus making them the perfect analyte for argentation chromatography. The direct coupling of argentation chromatography and ultrahigh-resolution mass spectrometry allows to continuously tracking the separation of the many different compounds by retention time and allows sensitive detection on a molecular level. Direct injection of a heavy crude oil into a ultrahigh-resolution mass spectrometer showed components with DBE of up to 25, whereas analytes with DBE of up to 35 could be detected only after separation with argentation chromatography. The reduced complexity achieved by the separation helps increasing the information depth.
Lilla Molnárné Guricza; Wolfgang Schrader. Argentation chromatography coupled to ultrahigh‐resolution mass spectrometry for the separation of a heavy crude oil. Journal of Chromatography A 2017, 1484, 41 -48.
AMA StyleLilla Molnárné Guricza, Wolfgang Schrader. Argentation chromatography coupled to ultrahigh‐resolution mass spectrometry for the separation of a heavy crude oil. Journal of Chromatography A. 2017; 1484 ():41-48.
Chicago/Turabian StyleLilla Molnárné Guricza; Wolfgang Schrader. 2017. "Argentation chromatography coupled to ultrahigh‐resolution mass spectrometry for the separation of a heavy crude oil." Journal of Chromatography A 1484, no. : 41-48.
A heavy crude oil has been treated with deuterated alkylating reagents (CD3I and C2D5I) and directly analyzed without any prior fractionation and chromatographic separation by high-field Orbitrap Fourier Transform Mass Spectrometry (FTMS) and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) using electrospray ionization (ESI). The reaction of a polycyclic aromatic sulfur heterocycles (PASHs) dibenzothiophene (DBT), in the presence of silver tetrafluoroborate (AgBF4) with ethyl iodide (C2H5I) in anhydrous dichloroethane (DCE) was optimized as a sample reaction to study heavy crude oil mixtures, and the reaction yield was monitored and determined by proton nuclear magnetic resonance spectroscopy (1H-NMR). The obtained conditions were then applied to a mixture of standard aromatic CH-, N-, O- and S-containing compounds and then a heavy crude oil, and only sulfur-containing compounds were selectively alkylated. The deuterium labeled alkylating reagents, iodomethane-d3 (CD3I) and iodoethane-d5 (C2D5I), were employed to the alkylation of heavy crude oil to selectively differentiate the tagged sulfur species from the original crude oil.
Xuxiao Wang; Wolfgang Schrader. Selective Analysis of Sulfur-Containing Species in a Heavy Crude Oil by Deuterium Labeling Reactions and Ultrahigh Resolution Mass Spectrometry. International Journal of Molecular Sciences 2015, 16, 30133 -30143.
AMA StyleXuxiao Wang, Wolfgang Schrader. Selective Analysis of Sulfur-Containing Species in a Heavy Crude Oil by Deuterium Labeling Reactions and Ultrahigh Resolution Mass Spectrometry. International Journal of Molecular Sciences. 2015; 16 (12):30133-30143.
Chicago/Turabian StyleXuxiao Wang; Wolfgang Schrader. 2015. "Selective Analysis of Sulfur-Containing Species in a Heavy Crude Oil by Deuterium Labeling Reactions and Ultrahigh Resolution Mass Spectrometry." International Journal of Molecular Sciences 16, no. 12: 30133-30143.