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Jürgen H. Gross - One of the best experts on this subject based on the ideXlab platform.
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from the discovery of field ionization to field desorption and Liquid Injection field desorption ionization mass spectrometry a journey from principles and applications to a glimpse into the future
European Journal of Mass Spectrometry, 2020Co-Authors: Jürgen H. GrossAbstract:The discovery of the ionizing effect of strong electric fields in the order of volts per Angstrom in the early 1950s eventually led to the development of field ionization-mass spectrometry (FI-MS). Due to the very low ion currents, and thus, limited by the instrumentation of the 1960s, it took some time for the, by then, new technique to become adopted for analytical applications. In FI-MS, volatile or at least vaporizable samples mainly deliver molecular ions, and consequently, mass spectra showing no or at least minor numbers of fragment ion signals. The next major breakthrough was achieved by overcoming the need to evaporate the analyte prior to ionization. This was accomplished in the early 1970s by simply depositing the samples onto the field emitter and led to field desorption-mass spectrometry (FD-MS). With FD-MS, a desorption ionization method had become available that paved the road to the mass spectral analysis of larger molecules of low to high polarity and even of organic salts. In FD-MS, all of these analytes deliver spectra with no or at least few fragment ion peaks. The last milestone was the development of Liquid Injection field desorption/ionization (LIFDI) in the early 2000s that allows for sample deposition under the exclusion of atmospheric oxygen and water. In addition to sampling under inert conditions, LIFDI also enables more robust and quicker operation than classical FI-MS and FD-MS procedures. The development and applications of FI, FD, and LIFDI had mutual interference with the mass analyzers that were used in combination with these methods. Vice versa, the demand for using these techniques on other than magnetic sector instruments has effectuated their adaptation to different types of modern mass analyzers. The journey started with magnetic sector instruments, almost skipped quadrupole analyzers, encompassed Fourier transform ion cyclotron resonance (FT-ICR) and orthogonal acceleration time-of-flight (oaTOF) analyzers, and finally arrived at Orbitraps. Even interfaces for continuous-flow LIFDI have been realized. Even though being niche techniques to some degree, one may be confident that FI, FD, and LIFDI have a promising future ahead of them. This Account takes you on the journey from principles and applications of the title methods to a glimpse into the future.
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self supplied Liquid Injection field desorption ionization ion source for an orthogonal time of flight instrument
Journal of the American Society for Mass Spectrometry, 2019Co-Authors: Mathias H Linden, Bernhard H Linden, Norbert Nieth, Jürgen H. GrossAbstract:A new implementation of a dedicated ion source for field ionization (FI), field desorption (FD), and Liquid Injection field desorption/ionization (LIFDI) for the JEOL AccuTOF GC series of orthogonal-acceleration time-of-flight instruments is presented. In contrast to existing implementations, this third-party LIFDI probe and source combination does not require the exchange of the entire ion source comprising ion source block and lens stack to switch from electron ionization (EI) to LIFDI. Rather, the methods may be swapped conveniently by only exchanging the ion source block for a mechanical probe guide and inserting the LIFDI probe in place of the standard direct insertion probe (DIP) via the vacuum lock. Further, this LIFDI setup does not require any changes of the electronics or software of the AccuTOF mass spectrometer because it is self-supplied in terms of power supply, observation optics, and computer control. The setup offers advanced FI/FD/LIFDI control features such as emission-controlled emitter heating current and emitter flash baking during elongated runs as required for gas chromatography-FI-mass spectrometry (MS). The LIFDI source and probe and its operation are reported in detail. FI spectra of the volatile analytes toluene, heptane, and pentafluoroiodobenzene are presented. LIFDI operation is demonstrated for the analysis of the saturated hydrocarbon dotriacontane and the low-mass hydrocarbon polymers polystyrene 484 and polystyrene 1050. Further, the air-sensitive 2nd-generation Hoveyda-Grubbs catalyst is analyzed by LIFDI-MS. For comparison with long-established LIFDI instrumentation, some of the spectra obtained with the new setup are also compared with those from a double-focusing magnetic sector instrument.
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reduced fragmentation in Liquid Injection field desorption ionization fourier transform ion cyclotron resonance mass spectrometry by use of helium for the thermalization of molecular ions
Rapid Communications in Mass Spectrometry, 2012Co-Authors: Bernhard H Linden, Jürgen H. GrossAbstract:RATIONALE: To exploit the softness of Liquid Injection field desorption/ionization (LIFDI), the molecular ions, M(+•), need to be transferred from their origin at the field emitter through the mass analyzer without disrupting their integrity. To preserve the molecular ions, ion-activating events like collisions must therefore be avoided. In hybrid quadrupole Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometers, however, multiple ion-guiding and ion-trapping events occur prior to mass analysis. The effects thereof compromised initial spectra from a LIFDI and electrospray ionization (ESI) combination (LIFDI-ESI) ion source and, thus, called for refined experimental conditions. METHODS: A hybrid quadrupole FT-ICR instrument equipped with a new LIFDI-ESI combination ion source was used to obtain LIFDI spectra of polystyrene 1050, of 2,3,4-tridodecyloxybenzaldehyde, and of sewing machine oil as well as a field ionization (FI) spectrum of pentafluoroiodobenzene. The abundance of molecular ions, M(+•), was optimized, in particular by variation of the trapping conditions inside the instrument's accumulation RF-hexapole ion trap. RESULTS: Ion-buffer gas collisions in the instrument's accumulation RF-hexapole ion trap were detrimental to the easy-to-fragment molecular ions of hydrocarbon species, whereas more robust even-electron ions were not affected. Exchanging the instrument's standard supply of argon buffer gas for helium resulted in a remarkable improvement. Together with further adjustments of potentials applied along the ion transfer path, hydrocarbon species could be analyzed. CONCLUSIONS: The use of helium buffer gas remarkably improved LIFDI spectra, because the loss of molecular ions by dissociation during transfer from the LIFDI source into the ICR cell was significantly reduced. Hydrocarbon species could be analyzed while fragmentation of ions was avoided for the most part.
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a Liquid Injection field desorption ionization electrospray ionization combination source for a fourier transform ion cyclotron resonance mass spectrometer
Journal of the American Society for Mass Spectrometry, 2011Co-Authors: Bernhard H Linden, Jürgen H. GrossAbstract:A new type of combination ion source has been devised. It unites two complementary ionization methods, i.e., Liquid Injection field desorption/ionization (LIFDI) and electrospray ionization (ESI). This LIFDI-ESI combination ion source has been constructed for a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. The LIFDI-ESI combination ion source can be switched between the LIFDI and ESI modes of operation within 15 min without breaking the vacuum. The source design and its operation are described. LIFDI-FT-ICR spectra of the ionic Liquid trihexyl(tetradecyl)-phosphonium tris(pentafluoroethyl)-trifluorophosphate, polyethylene glycol 600, 2,3,4-tridodecyloxy-benzaldehyde, and [60]fullerene are described.
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Liquid Injection field desorption ionization mass spectrometry of ionic Liquids
Journal of the American Society for Mass Spectrometry, 2007Co-Authors: Jürgen H. GrossAbstract:Ten ionic Liquids based on four types of organic cations, C+ (imidazolium, pyrrolidinium, pyridinium, and phosphonium), combined with various types of anions, A−, were analyzed by Liquid Injection field desorption/ionization-(LIFDI) mass spectrometry. For the purpose of LIFDI analysis the ionic Liquids were dissolved in methanol, acetonitrile or tetrahydrofuran at concentrations of 0.01–0.1 µl mL−1. The measurements were performed on a double-focusing magnetic sector instrument. In all ionic Liquid LIFDI spectra, the intact cation of the compound yielded the base peak accompanied by cluster ions of the general formula [C2A]+ and occasionally [C3A2]+. Tandem mass spectrometry and reconstructed ion chromatograms were employed to reveal the identity of the observed ions. Although limited to positive-ion mode, LIFDI also provided analytical information on the anions due to cluster ion formation. Depending on actual emitter condition and ionic Liquid the limit of detection in survey scans was determined to 5–50 pg of ionic Liquid.
Alan G. Marshall - One of the best experts on this subject based on the ideXlab platform.
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automated Liquid Injection field desorption ionization for fourier transform ion cyclotron resonance mass spectrometry
Analytical Chemistry, 2008Co-Authors: Donald F Smith, Ryan P. Rodgers, Tanner Schaub, Christopher L Hendrickson, Alan G. MarshallAbstract:We describe automation of Liquid Injection field desorption/ionization (LIFDI) for reproducible sample application, improved spectral quality, and high-throughput analyses. A commercial autosampler provides reproducible and unattended sample application. A custom-built field desorption (FD) controller allows data station or front panel control of source parameters including high-voltage limit/ramp rate, emitter heating current limit/ramp rate, and feedback control of emitter heating current based on ion current measurement. Automated LIFDI facilitates ensemble averaging of hundreds of Fourier transform ion cyclotron resonance mass spectra for increased dynamic range, mass accuracy, and S/N ratio relative to single-application FD experiments, as shown here for a South American crude oil. This configuration can be adapted to any mass spectrometer with an LIFDI probe.
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characterization of athabasca bitumen heavy vacuum gas oil distillation cuts by negative positive electrospray ionization and automated Liquid Injection field desorption ionization fourier transform ion cyclotron resonance mass spectrometry
Energy & Fuels, 2008Co-Authors: Donald F Smith, Ryan P. Rodgers, Parviz Rahimi, Alem Teclemariam, Alan G. MarshallAbstract:We have analyzed eight heavy vacuum gas oil (HVGO) distillation fractions, initial boiling point (IBP)−343, 343−375, 375−400, 400−425, 425−450, 450−475, 475−500, and 500−525 °C, of an Athabasca bitumen by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Acidic, basic, and nonpolar components were detected by negative-ion and positive-ion electrospray ionization (ESI) and automated Liquid Injection field desorption ionization (LIFDI) positive-ion FT-ICR MS. Ultrahigh mass resolving power (m/Δm50% ≈ 350 000) and high mass accuracy (<500 ppb) facilitate the assignment of a unique elemental composition to each peak in the mass spectrum. Thus, each distillate was characterized by mass, heteroatom class, type (number of rings and double bonds), and carbon number distribution to correlate compositional changes with increased boiling point. Negative-ion ESI FT-ICR MS identifies high relative abundance nonaromatic O2 species that span the entire distillation range. All ionization methods re...
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instrumentation and method for ultrahigh resolution field desorption ionization fourier transform ion cyclotron resonance mass spectrometry of nonpolar species
Analytical Chemistry, 2005Co-Authors: Tanner Schaub, Ryan P. Rodgers, Christopher L Hendrickson, John P Quinn, Alan G. MarshallAbstract:We describe the construction and application of a 9.4-T FT-ICR mass spectrometer interfaced to a commercial field desorption ion source for high-resolution, high-mass accuracy measurements of nonpolar species. The FT-ICR MS instrument includes a Liquid Injection field desorption ionization source, octopole ion guides, external octopole ion trap capable of an axial potential gradient for ion ejection, capacitively coupled open cylindrical ion trap, and pulsed gas valve for ion cooling. Model compound responses with regard to various source and instrument conditions provide a basis for interpretation of broadband mass spectra of complex mixtures. As an example, we demonstrate broadband speciation of a Gulf Coast crude oil, with respect to numerous heteroatomic classes, compound types (rings plus double bonds), and carbon number distributions.
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high resolution field desorption ionization fourier transform ion cyclotron resonance mass analysis of nonpolar molecules
Analytical Chemistry, 2003Co-Authors: Tanner Schaub, Christopher L Hendrickson, Kuangnan Qian, And John P Quinn, Alan G. MarshallAbstract:We report the first field desorption ionization broadband high-resolution (m/Δm50% ≈ 65 000) mass spectra. We have interfaced a field ionization/field desorption source to a home-built 9.4-T FT-ICR mass spectrometer. The instrumental configuration employs convenient sample introduction (in-source Liquid Injection) and external ion accumulation. We demonstrate the utility of this configuration by generating high-resolution positive-ion mass spectra of C60 and a midboiling crude oil distillate. The latter contains species not accessible by common soft-ionization methods, for example, low-voltage electron ionization, electrospray ionization, and matrix-assisted laser desorption/ionization. The present work demonstrates significant advantages of FI/FD FT-ICR MS for analysis of nonpolar molecules in complex mixtures.
Bernhard H Linden - One of the best experts on this subject based on the ideXlab platform.
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self supplied Liquid Injection field desorption ionization ion source for an orthogonal time of flight instrument
Journal of the American Society for Mass Spectrometry, 2019Co-Authors: Mathias H Linden, Bernhard H Linden, Norbert Nieth, Jürgen H. GrossAbstract:A new implementation of a dedicated ion source for field ionization (FI), field desorption (FD), and Liquid Injection field desorption/ionization (LIFDI) for the JEOL AccuTOF GC series of orthogonal-acceleration time-of-flight instruments is presented. In contrast to existing implementations, this third-party LIFDI probe and source combination does not require the exchange of the entire ion source comprising ion source block and lens stack to switch from electron ionization (EI) to LIFDI. Rather, the methods may be swapped conveniently by only exchanging the ion source block for a mechanical probe guide and inserting the LIFDI probe in place of the standard direct insertion probe (DIP) via the vacuum lock. Further, this LIFDI setup does not require any changes of the electronics or software of the AccuTOF mass spectrometer because it is self-supplied in terms of power supply, observation optics, and computer control. The setup offers advanced FI/FD/LIFDI control features such as emission-controlled emitter heating current and emitter flash baking during elongated runs as required for gas chromatography-FI-mass spectrometry (MS). The LIFDI source and probe and its operation are reported in detail. FI spectra of the volatile analytes toluene, heptane, and pentafluoroiodobenzene are presented. LIFDI operation is demonstrated for the analysis of the saturated hydrocarbon dotriacontane and the low-mass hydrocarbon polymers polystyrene 484 and polystyrene 1050. Further, the air-sensitive 2nd-generation Hoveyda-Grubbs catalyst is analyzed by LIFDI-MS. For comparison with long-established LIFDI instrumentation, some of the spectra obtained with the new setup are also compared with those from a double-focusing magnetic sector instrument.
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reduced fragmentation in Liquid Injection field desorption ionization fourier transform ion cyclotron resonance mass spectrometry by use of helium for the thermalization of molecular ions
Rapid Communications in Mass Spectrometry, 2012Co-Authors: Bernhard H Linden, Jürgen H. GrossAbstract:RATIONALE: To exploit the softness of Liquid Injection field desorption/ionization (LIFDI), the molecular ions, M(+•), need to be transferred from their origin at the field emitter through the mass analyzer without disrupting their integrity. To preserve the molecular ions, ion-activating events like collisions must therefore be avoided. In hybrid quadrupole Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometers, however, multiple ion-guiding and ion-trapping events occur prior to mass analysis. The effects thereof compromised initial spectra from a LIFDI and electrospray ionization (ESI) combination (LIFDI-ESI) ion source and, thus, called for refined experimental conditions. METHODS: A hybrid quadrupole FT-ICR instrument equipped with a new LIFDI-ESI combination ion source was used to obtain LIFDI spectra of polystyrene 1050, of 2,3,4-tridodecyloxybenzaldehyde, and of sewing machine oil as well as a field ionization (FI) spectrum of pentafluoroiodobenzene. The abundance of molecular ions, M(+•), was optimized, in particular by variation of the trapping conditions inside the instrument's accumulation RF-hexapole ion trap. RESULTS: Ion-buffer gas collisions in the instrument's accumulation RF-hexapole ion trap were detrimental to the easy-to-fragment molecular ions of hydrocarbon species, whereas more robust even-electron ions were not affected. Exchanging the instrument's standard supply of argon buffer gas for helium resulted in a remarkable improvement. Together with further adjustments of potentials applied along the ion transfer path, hydrocarbon species could be analyzed. CONCLUSIONS: The use of helium buffer gas remarkably improved LIFDI spectra, because the loss of molecular ions by dissociation during transfer from the LIFDI source into the ICR cell was significantly reduced. Hydrocarbon species could be analyzed while fragmentation of ions was avoided for the most part.
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a Liquid Injection field desorption ionization electrospray ionization combination source for a fourier transform ion cyclotron resonance mass spectrometer
Journal of the American Society for Mass Spectrometry, 2011Co-Authors: Bernhard H Linden, Jürgen H. GrossAbstract:A new type of combination ion source has been devised. It unites two complementary ionization methods, i.e., Liquid Injection field desorption/ionization (LIFDI) and electrospray ionization (ESI). This LIFDI-ESI combination ion source has been constructed for a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. The LIFDI-ESI combination ion source can be switched between the LIFDI and ESI modes of operation within 15 min without breaking the vacuum. The source design and its operation are described. LIFDI-FT-ICR spectra of the ionic Liquid trihexyl(tetradecyl)-phosphonium tris(pentafluoroethyl)-trifluorophosphate, polyethylene glycol 600, 2,3,4-tridodecyloxy-benzaldehyde, and [60]fullerene are described.
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Liquid Injection field desorption ionization of reactive transition metal complexes
Analytical and Bioanalytical Chemistry, 2006Co-Authors: Jürgen H. Gross, Norbert Nieth, Bernhard H Linden, Ulrike Blumbach, Frank J Richter, Michael E Tauchert, Rolf Tompers, Peter HofmannAbstract:Liquid Injection field desorption/ionization (LIFDI) has been applied to identify transition metal complexes that are highly reactive to air and moisture by mass spectrometry. The complexes of nickel and rhodium were supplied as dilute solutions (∼0.2 mg ml−1) in toluene, tetrahydrofuran or acetonitrile, and were applied onto the field desorption emitter inside the vacuum of the ion source under inert conditions by means of the Injection capillary unique to the LIFDI set-up. LIFDI mass spectrometry on a double-focusing magnetic sector instrument provided spectra exhibiting intense molecular ion peaks for the species investigated or signals that could easily be related to the target compound by assuming neutral loss of the weakest-bound ligand. Eventually, byproducts of the synthesis or other components resulting from incomplete reactions or some degree of decomposition were also detected.
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Liquid Injection field desorption ionization a new tool for soft ionization of samples including air sensitive catalysts and non polar hydrocarbons
European Journal of Mass Spectrometry, 2004Co-Authors: Bernhard H LindenAbstract:Mass analysis of air-sensitive samples, like organometallic catalysts, require inert sample preparation to avoid degradation of such reactive molecules. Non-polar samples like hydrocarbons are stable but, nonetheless, need soft ionization to reduce congestion of fragment peaks for analysis of complex mixtures. This paper describes a novel type of probe that combines the advantages of field ionization and field desorption (FI/FD) with an efficient Liquid inlet. The new method is called Liquid Injection field desorption ionization (LIFDI). Sample solutions are delivered to the emitter wire inside the ion source without breaking the vacuum. Sample preparation is reduced to dipping the LIFDI transfer capillary into another sample vial. In the case of air-sensitive samples kept under inert gas, the preparation is inert without special experimental effort. The new tool provides significantly raised sample throughput at excellent sensitivity.
Tanner Schaub - One of the best experts on this subject based on the ideXlab platform.
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automated Liquid Injection field desorption ionization for fourier transform ion cyclotron resonance mass spectrometry
Analytical Chemistry, 2008Co-Authors: Donald F Smith, Ryan P. Rodgers, Tanner Schaub, Christopher L Hendrickson, Alan G. MarshallAbstract:We describe automation of Liquid Injection field desorption/ionization (LIFDI) for reproducible sample application, improved spectral quality, and high-throughput analyses. A commercial autosampler provides reproducible and unattended sample application. A custom-built field desorption (FD) controller allows data station or front panel control of source parameters including high-voltage limit/ramp rate, emitter heating current limit/ramp rate, and feedback control of emitter heating current based on ion current measurement. Automated LIFDI facilitates ensemble averaging of hundreds of Fourier transform ion cyclotron resonance mass spectra for increased dynamic range, mass accuracy, and S/N ratio relative to single-application FD experiments, as shown here for a South American crude oil. This configuration can be adapted to any mass spectrometer with an LIFDI probe.
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instrumentation and method for ultrahigh resolution field desorption ionization fourier transform ion cyclotron resonance mass spectrometry of nonpolar species
Analytical Chemistry, 2005Co-Authors: Tanner Schaub, Ryan P. Rodgers, Christopher L Hendrickson, John P Quinn, Alan G. MarshallAbstract:We describe the construction and application of a 9.4-T FT-ICR mass spectrometer interfaced to a commercial field desorption ion source for high-resolution, high-mass accuracy measurements of nonpolar species. The FT-ICR MS instrument includes a Liquid Injection field desorption ionization source, octopole ion guides, external octopole ion trap capable of an axial potential gradient for ion ejection, capacitively coupled open cylindrical ion trap, and pulsed gas valve for ion cooling. Model compound responses with regard to various source and instrument conditions provide a basis for interpretation of broadband mass spectra of complex mixtures. As an example, we demonstrate broadband speciation of a Gulf Coast crude oil, with respect to numerous heteroatomic classes, compound types (rings plus double bonds), and carbon number distributions.
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high resolution field desorption ionization fourier transform ion cyclotron resonance mass analysis of nonpolar molecules
Analytical Chemistry, 2003Co-Authors: Tanner Schaub, Christopher L Hendrickson, Kuangnan Qian, And John P Quinn, Alan G. MarshallAbstract:We report the first field desorption ionization broadband high-resolution (m/Δm50% ≈ 65 000) mass spectra. We have interfaced a field ionization/field desorption source to a home-built 9.4-T FT-ICR mass spectrometer. The instrumental configuration employs convenient sample introduction (in-source Liquid Injection) and external ion accumulation. We demonstrate the utility of this configuration by generating high-resolution positive-ion mass spectra of C60 and a midboiling crude oil distillate. The latter contains species not accessible by common soft-ionization methods, for example, low-voltage electron ionization, electrospray ionization, and matrix-assisted laser desorption/ionization. The present work demonstrates significant advantages of FI/FD FT-ICR MS for analysis of nonpolar molecules in complex mixtures.
Ryan P. Rodgers - One of the best experts on this subject based on the ideXlab platform.
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automated Liquid Injection field desorption ionization for fourier transform ion cyclotron resonance mass spectrometry
Analytical Chemistry, 2008Co-Authors: Donald F Smith, Ryan P. Rodgers, Tanner Schaub, Christopher L Hendrickson, Alan G. MarshallAbstract:We describe automation of Liquid Injection field desorption/ionization (LIFDI) for reproducible sample application, improved spectral quality, and high-throughput analyses. A commercial autosampler provides reproducible and unattended sample application. A custom-built field desorption (FD) controller allows data station or front panel control of source parameters including high-voltage limit/ramp rate, emitter heating current limit/ramp rate, and feedback control of emitter heating current based on ion current measurement. Automated LIFDI facilitates ensemble averaging of hundreds of Fourier transform ion cyclotron resonance mass spectra for increased dynamic range, mass accuracy, and S/N ratio relative to single-application FD experiments, as shown here for a South American crude oil. This configuration can be adapted to any mass spectrometer with an LIFDI probe.
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characterization of athabasca bitumen heavy vacuum gas oil distillation cuts by negative positive electrospray ionization and automated Liquid Injection field desorption ionization fourier transform ion cyclotron resonance mass spectrometry
Energy & Fuels, 2008Co-Authors: Donald F Smith, Ryan P. Rodgers, Parviz Rahimi, Alem Teclemariam, Alan G. MarshallAbstract:We have analyzed eight heavy vacuum gas oil (HVGO) distillation fractions, initial boiling point (IBP)−343, 343−375, 375−400, 400−425, 425−450, 450−475, 475−500, and 500−525 °C, of an Athabasca bitumen by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Acidic, basic, and nonpolar components were detected by negative-ion and positive-ion electrospray ionization (ESI) and automated Liquid Injection field desorption ionization (LIFDI) positive-ion FT-ICR MS. Ultrahigh mass resolving power (m/Δm50% ≈ 350 000) and high mass accuracy (<500 ppb) facilitate the assignment of a unique elemental composition to each peak in the mass spectrum. Thus, each distillate was characterized by mass, heteroatom class, type (number of rings and double bonds), and carbon number distribution to correlate compositional changes with increased boiling point. Negative-ion ESI FT-ICR MS identifies high relative abundance nonaromatic O2 species that span the entire distillation range. All ionization methods re...
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instrumentation and method for ultrahigh resolution field desorption ionization fourier transform ion cyclotron resonance mass spectrometry of nonpolar species
Analytical Chemistry, 2005Co-Authors: Tanner Schaub, Ryan P. Rodgers, Christopher L Hendrickson, John P Quinn, Alan G. MarshallAbstract:We describe the construction and application of a 9.4-T FT-ICR mass spectrometer interfaced to a commercial field desorption ion source for high-resolution, high-mass accuracy measurements of nonpolar species. The FT-ICR MS instrument includes a Liquid Injection field desorption ionization source, octopole ion guides, external octopole ion trap capable of an axial potential gradient for ion ejection, capacitively coupled open cylindrical ion trap, and pulsed gas valve for ion cooling. Model compound responses with regard to various source and instrument conditions provide a basis for interpretation of broadband mass spectra of complex mixtures. As an example, we demonstrate broadband speciation of a Gulf Coast crude oil, with respect to numerous heteroatomic classes, compound types (rings plus double bonds), and carbon number distributions.