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Kawa S, Kaur J, Knorke H, Warneke Z, Wadsack M, Rohdenburg M, Nierstenhöfer M, Jenne C, Kenttämaa H, Warneke J. Generation and reactivity of the fragment ion [B 12I 8S(CN)] - in the gas phase and on surfaces. Analyst 2024; 149:2573-2585. [PMID: 38469706 DOI: 10.1039/d3an02175k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Gaseous fragment ions generated in mass spectrometers may be employed as "building blocks" for the synthesis of novel molecules on surfaces using ion soft-landing. A fundamental understanding of the reactivity of the fragment ions is required to control bond formation of deposited fragments in surface layers. The fragment ion [B12X11]- (X = halogen) is formed by collision-induced dissociation (CID) from the precursor [B12X12]2- dianion. [B12X11]- is highly reactive and ion soft-landing experiments have shown that this ion binds to the alkyl chains of organic molecules on surfaces. In this work we investigate whether specific modifications of the precursor ion affect the chemical properties of the fragment ions to such an extent that attachment to functional groups of organic molecules on surfaces occurs and binding of alkyl chains is prevented. Therefore, a halogen substituent was replaced by a thiocyanate substituent. CID of the precursor [B12I11(SCN)]2- ion preferentially yields the fragment ion [B12I8S(CN)]-, which shows significantly altered reactivity compared to the fragment ions of [B12I12]2-. [B12I8S(CN)]- has a previously unknown structural element, wherein a sulfur atom bridges three boron atoms. Gas-phase reactions with different neutral reactants (cyclohexane, dimethyl sulfide, and dimethyl amine) accompanied by theoretical studies indicate that [B12I8S(CN)]- binds with higher selectivity to functional groups of organic molecules than fragment ions of [B12I12]2- (e.g., [B12I11]- and [B12I9]-). These findings were further confirmed by ion soft-landing experiments, which showed that [B12I8S(CN)]- ions attacked ester groups of adipates and phthalates, whereas [B12I11]- ions only bound to alkyl chains of the same reagents.
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Affiliation(s)
- Sebastian Kawa
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany.
| | - Jaskiran Kaur
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907, USA
| | - Harald Knorke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany.
| | - Ziyan Warneke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany.
| | - Myriam Wadsack
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany.
| | - Markus Rohdenburg
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany.
| | - Marc Nierstenhöfer
- Anorganische Chemie, Fakultät für Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, Gaußstr. 20, 42119, Wuppertal, Germany
| | - Carsten Jenne
- Anorganische Chemie, Fakultät für Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, Gaußstr. 20, 42119, Wuppertal, Germany
| | - Hilkka Kenttämaa
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907, USA
| | - Jonas Warneke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany.
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, 04318, Leipzig, Germany
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Rohdenburg M, Warneke Z, Knorke H, Icker M, Warneke J. Chemical Synthesis with Gaseous Molecular Ions: Harvesting [B 12 Br 11 N 2 ] - from a Mass Spectrometer. Angew Chem Int Ed Engl 2023; 62:e202308600. [PMID: 37531598 DOI: 10.1002/anie.202308600] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 08/04/2023]
Abstract
Mass spectrometry frequently reveals the existence of transient gas phase ions that have not been synthesized in solution or in bulk. These elusive ions are, therefore, often considered to be primarily of analytical value in fundamental gas phase studies. Here, we provide proof-of-concept that the products of ion-molecule reactions in mass spectrometers may be collected on surfaces to generate condensed matter and thus serve as building blocks to synthesize new compounds. The highly reactive fragment anion [B12 Br11 ]- was generated in a mass spectrometer and converted to [B12 Br11 N2 ]- in the presence of molecular nitrogen followed by its mass-selection and soft-landing on surfaces. The molecular structure of [B12 Br11 N2 ]- , which has not been synthetically obtained before, was confirmed by conventional methods of molecular analysis, including nuclear magnetic resonance and infrared spectroscopy. The [B12 Br11 N2 ]- ion is stable on surfaces and in solution at room temperature, but thermal annealing induces elimination of N2 and provides access to the highly reactive intermediate [B12 Br11 ]- in the condensed phase, which can be further used as a reagent, for example, for electrophilic aromatic substitutions. Thus, isolation of [B12 Br11 N2 ]- expands the repertoire of the available diazo ions that can be employed as versatile intermediates in various chemical transformations.
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Affiliation(s)
- Markus Rohdenburg
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany
| | - Ziyan Warneke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany
| | - Harald Knorke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany
| | - Maik Icker
- Institut für Organische Chemie, Universität Leipzig, Linnéstr. 3, 04103, Leipzig, Germany
| | - Jonas Warneke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany
- Leibniz Institut für Oberflächenmodifizierung (IOM), Permoserstraße 15, 04318, Leipzig, Germany
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3
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Yu Y, Jiang J, Hua L, Xu Y, Chen C, Chen Y, Li H. Manipulation of Ion Conversion in Dichloromethane-Enhanced Vacuum Ultraviolet Photoionization Mass Spectrometry of Oxygenated Volatile Organic Compounds. Anal Chem 2023; 95:12940-12947. [PMID: 37582208 DOI: 10.1021/acs.analchem.3c02644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
The ion conversion processes in CH2Cl2-enhanced vacuum ultraviolet photoionization of oxygenated volatile organic compounds (OVOCs) have been systematically studied by regulating the pressure, humidity, and reaction time in the ionization source of a time-of-flight mass spectrometer. As the ionization source pressure increased from 100 to 1100 Pa, the main characteristic ions changed from CH2Cl+ to CH2Cl+(H2O), CH2OH+, and C2H4OH+ and then to the hydrated hydronium ions H3O+(H2O)n (n = 1, 2, 3). The total ion current (TIC) almost remained unchanged even if the humidity increased from 44 to 3120 ppmv, indicating interconversion between ions through ion-molecule reactions. The intensity of protonated methanol/ethanol (sample S) ion was almost linearly correlated with the intensity of H3O+(H2O)n, which pointed to the proton transfer reaction (PTR) mechanism. The reaction time was regulated by the electric field strength in the ionization region. The intensity variation trends of different ions with the reaction time indicated that a series of step-by-step ion-molecule reactions occurred in the ionization source, i.e., the primary ion CH2Cl+ reacted with H2O and converted to the intermediate product ions CH2OH+ and C2H4OH+, which then further reacted with H2O and led to the production of H3O+, and finally, the protonated sample ion SH+ was obtained through PTR with H3O+, as the ion-molecule reactions progressed. This study provides valuable insights into understanding the formation mechanism of some unexpected intermediate product ions and hydrated hydronium ions in dopant-enhanced VUV photoionization and also helps to optimize experimental conditions to enhance the sensitivity of OVOCs.
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Affiliation(s)
- Yi Yu
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Liaoning Key Laboratory for Mass Spectrometry Technology and Instrumentation, Dalian 116023, People's Republic of China
| | - Jichun Jiang
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
- Liaoning Key Laboratory for Mass Spectrometry Technology and Instrumentation, Dalian 116023, People's Republic of China
| | - Lei Hua
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
- Liaoning Key Laboratory for Mass Spectrometry Technology and Instrumentation, Dalian 116023, People's Republic of China
| | - Yiqian Xu
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Liaoning Key Laboratory for Mass Spectrometry Technology and Instrumentation, Dalian 116023, People's Republic of China
| | - Chuang Chen
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
- Liaoning Key Laboratory for Mass Spectrometry Technology and Instrumentation, Dalian 116023, People's Republic of China
| | - Yi Chen
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Liaoning Key Laboratory for Mass Spectrometry Technology and Instrumentation, Dalian 116023, People's Republic of China
| | - Haiyang Li
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
- Liaoning Key Laboratory for Mass Spectrometry Technology and Instrumentation, Dalian 116023, People's Republic of China
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Yan Y, Schmitt L, Khramchenkova A, Lengyel J. Ion transmission in an electrospray ionization-mass spectrometry interface using an S-lens. JOURNAL OF MASS SPECTROMETRY : JMS 2023; 58:e4955. [PMID: 37401114 DOI: 10.1002/jms.4955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/24/2023] [Accepted: 06/03/2023] [Indexed: 07/05/2023]
Abstract
We present the design and performance of an in-house built electrospray ionization-mass spectrometry (ESI-MS) interface equipped with an S-lens ion guide. The ion source was designed specifically for our ion beam experiments to investigate the chemical reactivity and deposition of the clusters and nanoparticles. It includes standard ESI-MS interface components, such as nanoelectrospray, ion transfer capillary, and the S-lens. A custom design enables systematic optimization of all relevant factors influencing ion formation and transfer through the interface. By varying the ESI voltage and flow rate, we determined the optimal operating conditions for selected silica emitters. A comparison of the pulled silica emitters with different tip inner diameters reveals that the total ion current is highest for the largest tip, whereas a tip with the smallest diameter exhibited the highest transmission efficiency through the ESI-MS interface. Ion transmission through the transfer capillary is strongly limited by its length, but the loss of ions can be reduced by increasing the capillary voltage and temperature. The S-lens was characterized over a wide range of RF frequencies and amplitudes. Maximum ion current was detected at RF amplitudes greater than 50 V peak-to-peak (p/p) and frequencies above 750 kHz, with a stable ion transmission region of about 20%. A factor of 2.6 increase in total ion current is observed for 650 kHz as RF amplitudes reach 400 V p/p. Higher RF amplitudes also focus the ions into a narrow beam, which mitigates their losses when passing through the ion guide.
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Affiliation(s)
- Yihui Yan
- Chair of Physical Chemistry, TUM School of Natural Sciences, Technical University of Munich, Garching, Germany
| | - Lucas Schmitt
- Chair of Physical Chemistry, TUM School of Natural Sciences, Technical University of Munich, Garching, Germany
| | - Anastasiya Khramchenkova
- Chair of Physical Chemistry, TUM School of Natural Sciences, Technical University of Munich, Garching, Germany
| | - Jozef Lengyel
- Chair of Physical Chemistry, TUM School of Natural Sciences, Technical University of Munich, Garching, Germany
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5
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Hitzemann M, Schaefer C, Kirk AT, Nitschke A, Lippmann M, Zimmermann S. Easy to assemble dielectric barrier discharge plasma ionization source based on printed circuit boards. Anal Chim Acta 2023; 1239:340649. [PMID: 36628746 DOI: 10.1016/j.aca.2022.340649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 11/14/2022] [Accepted: 11/20/2022] [Indexed: 11/29/2022]
Abstract
Here, we present a new and an easy to assemble dielectric barrier discharge plasma ionization source based on printed circuit boards with two parallel isolated electrodes for generating a plasma inside an inert fused silica capillary. For demonstration, this plasma source is coupled to an ion mobility spectrometer. With two different sample gas feeds the analytes can either pass through the plasma or bypass the plasma before entering the reaction region of the ion mobility spectrometer, allowing for different ionization pathways, e.g. electron impact ionization, ionization by excited species, e.g. helium metastables, or chemical ionization via reactant ions generated inside or downstream of the plasma. The plasma source, in particular, the electrode geometry and the capillary diameter were designed with the help of electric field simulations. A rectangular electrode with a height of at least twice the outer diameter of the capillary turned out to be ideal, in both the simulation and the experiment. Furthermore, a simple control electronics has been developed, which can be easily applied to other plasma sources. With the plasma source presented here, detection limits in the mid pptv range have been reached.
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Affiliation(s)
- Moritz Hitzemann
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Appelstr. 9A, 30167, Hannover, Germany.
| | - Christoph Schaefer
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Appelstr. 9A, 30167, Hannover, Germany
| | - Ansgar T Kirk
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Appelstr. 9A, 30167, Hannover, Germany
| | - Alexander Nitschke
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Appelstr. 9A, 30167, Hannover, Germany
| | - Martin Lippmann
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Appelstr. 9A, 30167, Hannover, Germany
| | - Stefan Zimmermann
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Appelstr. 9A, 30167, Hannover, Germany
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6
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Derpmann V, Müller D, Haack A, Wissdorf W, Kersten H, Benter T. Charging Effects in Inlet Capillaries. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1678-1691. [PMID: 36001770 DOI: 10.1021/jasms.2c00130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Glass or metal inlet capillaries are commonly used for flow restriction in atmospheric pressure ionization mass spectrometers. They exhibit a high ion transmission rate and stability at most operating conditions. However, transferring unipolar currents of ions through inlet capillaries can lead to sudden signal dropouts or drifts of the signal intensity, particularly when materials of different conductivity are in contact with the capillary duct. Molecular layers of water and other gases such as liquid chromatography solvents always form on the surfaces of inlet capillaries at atmospheric pressure ionization conditions. These surface layers play a major role in ion transmission and the occurrence of charging effects, as ions adsorb on the capillary walls as well, charging the walls to electric potentials of up to kilovolts and eventually leading to a hindrance of ion transport into or through the capillary duct. In this work, surface charging effects are reported in dependence on the capillary material, i.e., borosilicate glass, (reduced) lead silicate, quartz, and metal. Low electrical conductance materials show a more pronounced long-term signal drift (e.g., quartz), while higher electrical conductance materials lead to stable long-term behavior.
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Affiliation(s)
- Valerie Derpmann
- Physical and Theoretical Chemistry, University of Wuppertal, Gausstrasse 20, 42119 Wuppertal, Germany
| | - David Müller
- Physical and Theoretical Chemistry, University of Wuppertal, Gausstrasse 20, 42119 Wuppertal, Germany
| | - Alexander Haack
- Physical and Theoretical Chemistry, University of Wuppertal, Gausstrasse 20, 42119 Wuppertal, Germany
| | - Walter Wissdorf
- Physical and Theoretical Chemistry, University of Wuppertal, Gausstrasse 20, 42119 Wuppertal, Germany
| | - Hendrik Kersten
- Physical and Theoretical Chemistry, University of Wuppertal, Gausstrasse 20, 42119 Wuppertal, Germany
| | - Thorsten Benter
- Physical and Theoretical Chemistry, University of Wuppertal, Gausstrasse 20, 42119 Wuppertal, Germany
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Walz A, Stoiber K, Huettig A, Schlichting H, Barth JV. Navigate Flying Molecular Elephants Safely to the Ground: Mass-Selective Soft Landing up to the Mega-Dalton Range by Electrospray Controlled Ion-Beam Deposition. Anal Chem 2022; 94:7767-7778. [PMID: 35609119 PMCID: PMC9178560 DOI: 10.1021/acs.analchem.1c04495] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The prototype of a highly versatile and efficient preparative mass spectrometry system used for the deposition of molecules in ultrahigh vacuum (UHV) is presented, along with encouraging performance data obtained using four model species that are thermolabile or not sublimable. The test panel comprises two small organic compounds, a small and very large protein, and a large DNA species covering a 4-log mass range up to 1.7 MDa as part of a broad spectrum of analyte species evaluated to date. Three designs of innovative ion guides, a novel digital mass-selective quadrupole (dQMF), and a standard electrospray ionization (ESI) source are combined to an integrated device, abbreviated electrospray controlled ion-beam deposition (ES-CIBD). Full control is achieved by (i) the square-wave-driven radiofrequency (RF) ion guides with steadily tunable frequencies, including a dQMF allowing for investigation, purification, and deposition of a virtually unlimited m/z range, (ii) the adjustable landing energy of ions down to ∼2 eV/z enabling integrity-preserving soft landing, (iii) the deposition in UHV with high ion beam intensity (up to 3 nA) limiting contaminations and deposition time, and (iv) direct coverage control via the deposited charge. The maximum resolution of R = 650 and overall efficiency up to Ttotal = 4.4% calculated from the solution to UHV deposition are advantageous, whereby the latter can be further enhanced by optimizing ionization performance. In the setup presented, a scanning tunneling microscope (STM) is attached for in situ UHV investigations of deposited species, demonstrating a selective, structure-preserving process and atomically clean layers.
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Affiliation(s)
- Andreas Walz
- Physics Department E20, Technical University of Munich, 85748 Garching, Germany
| | - Karolina Stoiber
- Physics Department E20, Technical University of Munich, 85748 Garching, Germany
| | - Annette Huettig
- Physics Department E20, Technical University of Munich, 85748 Garching, Germany
| | - Hartmut Schlichting
- Physics Department E20, Technical University of Munich, 85748 Garching, Germany
| | - Johannes V Barth
- Physics Department E20, Technical University of Munich, 85748 Garching, Germany
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Requirements and attributes of nano-resonator mass spectrometry for the analysis of intact viral particles. Anal Bioanal Chem 2021; 413:7147-7156. [PMID: 34235570 DOI: 10.1007/s00216-021-03511-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/21/2021] [Accepted: 06/28/2021] [Indexed: 10/20/2022]
Abstract
When studying viruses, the most prevalent aspects that come to mind are their structural and functional features, but this leaves in the shadows a quite universal characteristic: their mass. Even if approximations can be derived from size and density measurements, the multi MDa to GDa mass range, featuring a majority of viruses, has so far remained largely unexplored. Recently, nano-electromechanical resonator-based mass spectrometry (NEMS-MS) has demonstrated the ability to measure the mass of intact DNA filled viral capsids in excess of 100 MDa. However, multiple factors have to be taken in consideration when performing NEMS-MS measurements. In this article, phenomena influencing NEMS-MS mass estimates are listed and discussed, including some particle's extraneous physical properties (size, aspect ratio, stiffness), and the influence of frequency noise and device fabrication defects. These factors being accounted for, we could begin to notice subtler effects linked with (e.g.) particle desolvation as a function of operating parameters. Graphical abstract.
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Han Z, Chen LC. Electrospray Ionization Inside the Ion Inlet Tube: Multijet Mode Operation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1821-1828. [PMID: 34167294 DOI: 10.1021/jasms.1c00157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We investigated the electrospray ionization inside the narrow channel of the ion inlet tube. An insulating emitter capillary made of fused silica with a 0.2 mm outer diameter was inserted into the ion inlet tubes with a 0.5 and 0.6 mm inner diameter to aspirate all the charged droplets. A custom-made ion inlet tube with two side holes near its entrance is used to observe the spraying condition. The spray current is measured and monitored during the MS acquisition using isolation amplifiers. Because the emitter is cylindrically surrounded in close proximity by the metallic inner wall, it is difficult to obtain a stable and symmetric Taylor cone with its apex at the center of the emitter. Instead, a stable operation under a flow rate of 1-4 μL/min is found to be in the form of a multicone-jet mode with two or more Taylor cones anchoring around the rim of the emitter. The emitted charged droplet jets are dragged from hitting the wall by the fast-flowing air inside the inlet tube. Comparison with the typical cone-jet and multijet mode operated several millimeters outside the inlet capillary shows signal enhancements for protein standards.
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Affiliation(s)
- Zhongbao Han
- Faculty of Engineering, University of Yamanashi, 4-3-11, Takeda, Kofu, Yamanashi 400-8511, Japan
| | - Lee Chuin Chen
- Faculty of Engineering, University of Yamanashi, 4-3-11, Takeda, Kofu, Yamanashi 400-8511, Japan
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10
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Rinke G, Harnau L, Rauschenbach S. Material and Charge Transport of Large Organic Salt Clusters and Nanoparticles in Electrospray Ion Beam Deposition. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1648-1658. [PMID: 33656859 DOI: 10.1021/jasms.0c00311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Electrospray ion beam deposition (ES-IBD) or ion soft landing has been demonstrated as a technique suitable for processing nonvolatile molecules in vacuum under perfectly controlled conditions, an approach also desirable for the deposition of nanoparticles. Here, we present results from several approaches to generate, characterize, and deposit nanoparticle ion beams in vacuum for deposition. We focus on cluster ion beams generated by ESI of organic salt solutions. Small cluster ions of the salts appear in the mass spectra as defined peaks. In addition, we find nanoparticle-sized aggregates, appearing as a low intensity background at high m/z-ratio, and show by IBD experiments that these clusters carry the major amount of material in the ion beam. This transition from clusters to nanoparticles, and their successful deposition, shows that ES-IBD can in principle handle ion beams of very heavy and highly charged nanoparticles. In related experiments, however, we found the deposition of nanoparticles from dispersions to be of low reproducibility, due to the lack of control by mass spectrometry.
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Affiliation(s)
- Gordon Rinke
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, DE-70569 Stuttgart, Germany
| | - Ludger Harnau
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, DE-70569 Stuttgart, Germany
| | - Stephan Rauschenbach
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, DE-70569 Stuttgart, Germany
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11
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Dryahina K, Som S, Smith D, Španěl P. Reagent and analyte ion hydrates in secondary electrospray ionization mass spectrometry (SESI-MS), their equilibrium distributions and dehydration in an ion transfer capillary: Modelling and experiments. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35:e9047. [PMID: 33434952 DOI: 10.1002/rcm.9047] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/11/2021] [Accepted: 01/11/2021] [Indexed: 06/12/2023]
Abstract
RATIONALE Secondary electrospray ionization (SESI) in a water spray environment at atmospheric pressure involves the reactions of hydrated hydronium reagent ions, H3 O+ (H2 O)n , with trace analyte compounds in air samples. Understanding the formation and dehydration of reagent and analyte ions is the foundation for meaningful quantification of trace compounds by SESI-mass spectrometry (MS). METHODS A numerical model based on gas-phase ion thermochemistry is developed that describes equilibria in H3 O+ (H2 O)n reagent cluster ion distributions and ligand switching reactions with polar NH3 molecules leading to equilibrated hydrated ammonium ions NH4 + (H2 O)m . The model predictions are compared with experimental results obtained using a cylindrical SESI source coupled to an ion-trap mass spectrometer via a heated ion transfer capillary. Non-polar isoprene, C5 H8 , was used to further probe the nature of the reagent ions. RESULTS Equilibrium distributions of H3 O+ (H2 O)n ions and their reactions with NH3 molecules have been characterized by the model in the near-atmospheric pressure SESI source. NH3 analyte molecules displace H2 O ligands from the H3 O+ (H2 O)n ions at the collisional rate forming NH4 + (H2 O)m ions, which travel through the heated ion transfer capillary losing H2 O molecules. The data for variable NH3 concentrations match the model predictions and the C5 H8 test substantiates the notion of dehydration in the heated capillary. CONCLUSIONS Large cluster ions formed in the SESI region are dehydrated to H3 O+ (H2 O)1,2,3 and NH4 + (H2 O)1,2 while passing through the heated capillary, and considerable diffusion losses also occur. This phenomenon is also predicted for other polar analyte molecules, A, that can undergo similar switching reactions, thus forming AH+ and AH+ (H2 O)m analyte ions.
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Affiliation(s)
- Kseniya Dryahina
- J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, Prague 8, 18223, Czech Republic
| | - Suman Som
- J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, Prague 8, 18223, Czech Republic
| | - David Smith
- J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, Prague 8, 18223, Czech Republic
| | - Patrik Španěl
- J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, Prague 8, 18223, Czech Republic
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12
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Lewis Z, Jackson BA, Crampton A, Ray AD, Holman SW. Towards a generic method for ion chromatography/mass spectrometry of low-molecular-weight amines in pharmaceutical drug discovery and development. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34 Suppl 4:e8680. [PMID: 31778589 DOI: 10.1002/rcm.8680] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 11/27/2019] [Accepted: 11/27/2019] [Indexed: 06/10/2023]
Abstract
RATIONALE Low-molecular-weight amines are encountered in pharmaceutical analysis, e.g. as reactants in chemical syntheses, but are challenging to analyse using ultrahigh-performance liquid chromatography/mass spectrometry (UHPLC/MS) due to their high polarity causing poor retention. Ion chromatography/mass spectrometry (IC/MS) is an emerging technique for polar molecule analysis that offers better separation. A generic IC/MS method would overcome problems associated with using UHPLC/MS in drug discovery and development environments. METHODS Amine standards were analysed using IC/MS with gradient elution (variety of column temperatures evaluated). An electrospray ionisation (ESI) quadrupole mass spectrometer was operated in positive ion polarity in scanning mode. The make-up flow composition was evaluated by assessing the performance of a range of organic modifiers (acetonitrile, ethanol, methanol) and additives (acetic acid, formic acid, methanesulfonic acid). The ESI conditions were optimised to minimise adduct formation and promote generation of protonated molecules. RESULTS The performance attributes were investigated and optimised for low-molecular-weight amine analysis. Organic solvents and acidic additives were evaluated as make-up flow components to promote ESI, with 0.05% acetic acid in ethanol optimal for producing protonated molecules. The hydrogen bonding capability of amines led to abundant protonated molecule-solvent complexes; optimisation of source conditions reduced these, with collision-induced dissociation voltage having a strong effect. The detection limit was ≤1.78 ng for the amines analysed, which is fit-for-purpose for an open-access chemistry environment. CONCLUSIONS This study demonstrates the value of IC/MS for analysing low-molecular-weight amines. Good chromatographic separation of mixtures was possible without derivatisation. Ionisation efficiency was greatest using a make-up flow of 0.05% acetic acid in ethanol, and optimisation of ESI source conditions promoted protonated molecule generation for easy determination of molecular weight.
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Affiliation(s)
- Zoe Lewis
- Global Chemical Development, Pharmaceutical Technology & Development, AstraZeneca, Macclesfield Campus, Macclesfield, SK10 2NA, UK
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Bethany A Jackson
- Global Chemical Development, Pharmaceutical Technology & Development, AstraZeneca, Macclesfield Campus, Macclesfield, SK10 2NA, UK
| | - Alex Crampton
- Global Chemical Development, Pharmaceutical Technology & Development, AstraZeneca, Macclesfield Campus, Macclesfield, SK10 2NA, UK
| | - Andrew D Ray
- Global Product Development, Pharmaceutical Technology & Development, AstraZeneca, Macclesfield Campus, Macclesfield, SK10 2NA, UK
| | - Stephen W Holman
- Global Chemical Development, Pharmaceutical Technology & Development, AstraZeneca, Macclesfield Campus, Macclesfield, SK10 2NA, UK
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Chiarinelli J, Bolognesi P, Avaldi L. Ion optics simulation of an ion beam setup coupled to an electrospray ionization source, strengths, and limitations. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:073203. [PMID: 32752820 DOI: 10.1063/5.0006641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
A unified approach to achieve a start-to-end ion optics simulation of an ion beam apparatus coupled to an electrospray ionization source is presented. We demonstrate that simulations enable reliable information on the behavior and operation of the apparatus to be obtained, but due to the collisions with the buffer gas in the initial stages of the setup, the results concerning the kinetic energy of the ion beam must be treated with care.
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Affiliation(s)
- J Chiarinelli
- CNR-ISM, Area della Ricerca Roma 1, Monterotondo Scalo, Roma 00015, Italy
| | - P Bolognesi
- CNR-ISM, Area della Ricerca Roma 1, Monterotondo Scalo, Roma 00015, Italy
| | - L Avaldi
- CNR-ISM, Area della Ricerca Roma 1, Monterotondo Scalo, Roma 00015, Italy
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Chen LC. A Plug-and-Play High-Pressure ESI Source with an Emitter at Ground Potential and Its Application to High-Temperature Capillary LC-MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:1015-1018. [PMID: 32239928 DOI: 10.1021/jasms.0c00052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A new high-pressure ESI source that can be readily used for commercial API mass spectrometers in a plug-and-play manner without any modification on the ion sampling interface is introduced. The emitter can be operated at ground potential, and the positive mode electrospray is generated by applying a negative high potential to the counter electrode. A shielding electrode effectively shields the opposing electric field and improves the ion transmission. This feature facilitates the direct connection of the ESI emitter to the electrically grounded components. The application of the present ion source to the high-temperature (>100 °C) capillary liquid chromatography for high-speed separation of peptide and proteins is demonstrated using a monolithic polymeric column.
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Affiliation(s)
- Lee Chuin Chen
- Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan
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Wang W, Bajic S, John B, Emerson DR. Numerical Simulation of Flow Field and Ion Transport for Different Ion Source Sampling Interfaces of a Mass Spectrometer. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:840-855. [PMID: 32134651 DOI: 10.1021/jasms.9b00103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Understanding ion transport mechanisms in the flow expansion section of the first vacuum region of a mass spectrometer (MS) with an atmospheric pressure ionization source is essential for optimizing the MS sampling interface design. In this study, numerical simulations of three types of ions in two different MS interface designs have been carried out. In contrast to previously reported numerical studies, nonequilibrium gas dynamics due to rarefied gas effects has been considered in modeling the flow expansion and a realistic space charge effect has been considered in a continuous ion injection mode. Numerical simulations reveal that a flat plate interface has a higher peak buffer gas velocity but a narrower zone of silence compared to the conical interface. Shock wave structures are clearly captured, and the Knudsen number distribution is displayed. Simulation results show that in the axial direction the buffer gas effect is much stronger than the electric force effect in the current configuration. The conical interface leads to both a strong ion acceleration in the zone of silence and a strong ion deceleration downstream. In the radial direction, both the electric force and buffer gas drag force play an important role. The conical interface introduces a relatively stronger ion focusing effect from the radial buffer gas effect and a stronger ion dispersion from the radial electric force than the flat plate interface. The net effect for the current configuration is an increase in ion losses for the conical interface. Nanoelectrospray ionization experiments were carried out to validate the ion transmission efficiency.
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Affiliation(s)
- Wei Wang
- STFC, Daresbury Laboratory, Warrington, Cheshire WA4 4AD, U.K
- Waters Corporation, Altrincham Rd, Wilmslow, Cheshire SK9 4AX, U.K
| | - Steve Bajic
- Waters Corporation, Altrincham Rd, Wilmslow, Cheshire SK9 4AX, U.K
| | - Benzi John
- STFC, Daresbury Laboratory, Warrington, Cheshire WA4 4AD, U.K
| | - David R Emerson
- STFC, Daresbury Laboratory, Warrington, Cheshire WA4 4AD, U.K
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