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Trimpin S, Inutan ED, Pagnotti VS, Karki S, Marshall DD, Hoang K, Wang B, Lietz CB, Richards AL, Yenchick FS, Lee C, Lu IC, Fenner M, Madarshahian S, Saylor S, Chubatyi ND, Zimmerman T, Moreno-Pedraza A, Wang T, Adeniji-Adele A, Meher AK, Madagedara H, Owczarzak Z, Musavi A, Hendrickson TL, Peacock PM, Tomsho JW, Larsen BS, Prokai L, Shulaev V, Pophristic M, McEwen CN. Direct sub-atmospheric pressure ionization mass spectrometry: Evaporation/sublimation-driven ionization is amazing, fundamentally, and practically. JOURNAL OF MASS SPECTROMETRY : JMS 2024; 59:e5018. [PMID: 38736378 DOI: 10.1002/jms.5018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/08/2023] [Accepted: 03/04/2024] [Indexed: 05/14/2024]
Abstract
This paper covers direct sub-atmospheric pressure ionization mass spectrometry (MS). The discovery, applications, and mechanistic aspects of novel ionization processes for use in MS that are not based on the high-energy input from voltage, laser, and/or high temperature but on sublimation/evaporation within a region linking a higher to lower pressure and modulated by heat and collisions, are discussed, including how this new reality has guided a series of discoveries, instrument developments, and commercialization. A research focus, inter alia, is on how best to understand, improve, and use these novel ionization processes, which convert volatile and nonvolatile compounds from solids (sublimation) or liquids (evaporation) into gas-phase ions for analysis by MS providing reproducible, accurate, sensitive, and prompt results. Our perception on how these unprecedented versus traditional ionization processes/methods relate to each other, how they can be made to coexist on the same mass spectrometer, and an outlook on new and expanded applications (e.g., clinical, portable, fast, safe, and autonomous) is presented, and is based on ST's Opening lecture presentation at the Nordic Mass spectrometry Conference, Geilo, Norway, January 2023. Focus will be on matrix-assisted ionization (MAI) and solvent-assisted ionization (SAI) MS covering the period from 2010 to 2023; a potential paradigm shift in the making.
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Affiliation(s)
- Sarah Trimpin
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
- MSTM, LLC, Newark, Delaware, USA
| | - Ellen D Inutan
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
- MSTM, LLC, Newark, Delaware, USA
- Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
| | - Vincent S Pagnotti
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, Pennsylvania, USA
| | - Santosh Karki
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
- MSTM, LLC, Newark, Delaware, USA
| | - Darrell D Marshall
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
- MSTM, LLC, Newark, Delaware, USA
| | - Khoa Hoang
- MSTM, LLC, Newark, Delaware, USA
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, Pennsylvania, USA
| | - Beixi Wang
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
| | | | - Alicia L Richards
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
| | - Frank S Yenchick
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
| | - Chuping Lee
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
| | - I-Chung Lu
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
- Department of Chemistry, National Chung Hsing University, Taichung, Taiwan
| | - Madeleine Fenner
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, Pennsylvania, USA
| | - Sara Madarshahian
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, Pennsylvania, USA
| | - Sarah Saylor
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, Pennsylvania, USA
| | - Nicolas D Chubatyi
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, Pennsylvania, USA
| | - Teresa Zimmerman
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
| | | | - Tongwen Wang
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, Pennsylvania, USA
| | - Adetoun Adeniji-Adele
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, Pennsylvania, USA
| | - Anil K Meher
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
- MSTM, LLC, Newark, Delaware, USA
| | - Hasini Madagedara
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
| | - Zachary Owczarzak
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
| | - Ahmed Musavi
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
| | | | | | - John W Tomsho
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, Pennsylvania, USA
| | | | - Laszlo Prokai
- Department of Pharmacology and Neuroscience, The University of North Texas Health Science Center at Forth Worth, Fort Worth, Texas, USA
| | - Vladimir Shulaev
- Department of Biological Sciences, The University of North Texas, Denton, Texas, USA
| | - Milan Pophristic
- MSTM, LLC, Newark, Delaware, USA
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, Pennsylvania, USA
| | - Charles N McEwen
- MSTM, LLC, Newark, Delaware, USA
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, Pennsylvania, USA
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Trimpin S, Inutan E, Coffinberger H, Hoang K, Yenchick F, Wager-Miller J, Pophristic M, Mackie K, McEwen CN. Instrumentation development, improvement, simplification, and miniaturization: The multifunctional plate source for use in mass spectrometry. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2023; 29:276-291. [PMID: 37999746 DOI: 10.1177/14690667231211486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
In remembrance of Prof. Dr Przybylski, we are presenting a vision towards his beloved mass spectrometry (MS) and its far-reaching promises outside of the academic laboratory. Sub-atmospheric pressure (AP) ionization MS is well positioned to make a step-change in direct ionization, a concept that allows sublimation/evaporation ionization and mass analyses of volatile and nonvolatile molecules from clean or dirty samples, directly, accurately, sensitively, and in a straightforward manner that has the potential to expand the field of MS into unchartered application areas. Contrary to ambient ionization MS, ionization commences in the sub-AP region of the mass spectrometer, important for practical and safety reasons, and offers inter alia, simplicity, speed, sensitivity, and robustness directly from real-world samples without cleanup. The plate source concept, presented here, provides an easy to use, rapid, and direct sample introduction from AP into the sub-AP of a mass spectrometer. Utilizing sub-AP ionization MS based on the plate source concept, small to large molecules from various environments that would be deemed too dirty for some direct MS methods are demonstrated. The new source concept can be expanded to include multiple ionization methods using the same plate source "front end" without the need to vent the mass spectrometer between the different methods, thus allowing ionization of more compounds on the same mass spectrometer for which any one ionization method may be insufficient. Examples such as fentanyl, gamma-hydroxybutyric acid, clozapine, 1-propionyllysergic acid, hydrocodone angiotensin I and II, myoglobin, and carbonic anhydrase are included.
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Affiliation(s)
- Sarah Trimpin
- Wayne State University, Detroit, MI, USA
- Research and Development, MSTM, LLC, Philadelphia, PA, USA
| | - Ellen Inutan
- Department of Chemistry, Mindanao State University-Illigan Institute of Technology, Illigan City, Philippines
| | - Hope Coffinberger
- Research and Development, MSTM, LLC, Philadelphia, PA, USA
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, PA, USA
| | - Khoa Hoang
- Research and Development, MSTM, LLC, Philadelphia, PA, USA
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, PA, USA
| | | | - James Wager-Miller
- Psychological and Brain Sciences Campus, Indiana University, Bloomington, IN, USA
| | - Milan Pophristic
- Research and Development, MSTM, LLC, Philadelphia, PA, USA
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, PA, USA
| | - Ken Mackie
- Psychological and Brain Sciences Campus, Indiana University, Bloomington, IN, USA
| | - Charles N McEwen
- Research and Development, MSTM, LLC, Philadelphia, PA, USA
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, PA, USA
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Trimpin S. A tutorial: Laserspray ionization and related laser-based ionization methods for use in mass spectrometry. MASS SPECTROMETRY REVIEWS 2023; 42:2234-2267. [PMID: 37462443 DOI: 10.1002/mas.21762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 09/30/2021] [Accepted: 11/15/2021] [Indexed: 08/09/2023]
Abstract
This Tutorial is to provide a summary of parameters useful for successful outcomes of laserspray ionization (LSI) and related methods that employ a laser to ablate a matrix:analyte sample to produce highly charged ions. In these methods the purpose of the laser is to transfer matrix-analyte clusters into the gas phase. Ions are hypothesized to be produced by a thermal process where emitted matrix:analyte gas-phase particles/clusters are charged and loss of matrix from the charged particles leads to release of the analyte ions into the gas phase. The thermal energy responsible for the charge-separation process is relatively low and not necessarily supplied by the laser; a heated inlet tube linking atmospheric pressure with the first vacuum stage of a mass spectrometer is sufficient. The inlet becomes the "ion source", and inter alia, pressure, temperature, and the matrix, which can be a solid, liquid, or combinations, become critical parameters. Injecting matrix:analyte into a heated inlet tube using laser ablation, a shockwave, or simply tapping, all produce the similar mass spectra. Applications are provided that showcase new opportunities in the field of mass spectrometry.
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Affiliation(s)
- Sarah Trimpin
- Department of Chemistry, Wayne State University, Detroit, Michigan, USA
- MSTM, LLC, Newark, Delaware, USA
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Xu C, Ruan H, Wang W, Li H. Triboionization in Discontinuous Atmospheric Pressure Inlet for a Miniature Ion Trap Mass Spectrometer. Anal Chem 2021; 93:15897-15904. [PMID: 34817157 DOI: 10.1021/acs.analchem.1c02611] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Discontinuous atmospheric pressure interface (DAPI) consisting of a pinch valve, a silicone tube, and two metal capillaries has been widely used in miniature mass spectrometry. It is interesting that clear ion signals could be observed even when the extra ionization source was turned off. In-depth analysis suggested that this new ionization phenomenon known as triboionization is based on the surface friction on the inner surface of the silicone tube during the on/off of the pinch valve. In this study, triboionization in the DAPI of a miniature ion trap mass spectrometer was investigated. It was discovered that the signal intensity depended greatly on the material and the roughness of the silicone tube used in the DAPI. By rubbing the inner surface of the silicone tube, for example, the signal intensity can increase by nearly 20 times. Two connected pinch valves were developed to study the effects of the discharge pressure, the number, and the frequency of on/off of the pinch valve on triboionization, which were verified to have a large impact on the product ions. In addition, the humidity of the inner surface of the silicone tube impacted the signal intensity of product ions and the mass spectrum patterns, where the product ions were typically protonated ions. As the humidity increases, the signal intensity of analytes with high proton affinity increases accordingly. This triboionization source, which does not require heat, light, radiation, auxiliary gas, or solution, has been preliminarily proved to have potential for surface detection after continuous enrichment.
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Affiliation(s)
- Chuting Xu
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS), 457 Zhongshan Road, Dalian 116023, People's Republic of China.,University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, People's Republic of China.,Dalian Key Laboratory for Online Analytical Instrumentation, 457 Zhongshan Road, Dalian 116023, People's Republic of China
| | - Huiwen Ruan
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS), 457 Zhongshan Road, Dalian 116023, People's Republic of China.,University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, People's Republic of China.,Dalian Key Laboratory for Online Analytical Instrumentation, 457 Zhongshan Road, Dalian 116023, People's Republic of China
| | - Weiguo Wang
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS), 457 Zhongshan Road, Dalian 116023, People's Republic of China.,Dalian Key Laboratory for Online Analytical Instrumentation, 457 Zhongshan Road, Dalian 116023, People's Republic of China
| | - Haiyang Li
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS), 457 Zhongshan Road, Dalian 116023, People's Republic of China.,Dalian Key Laboratory for Online Analytical Instrumentation, 457 Zhongshan Road, Dalian 116023, People's Republic of China
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Murray KK. Lasers for matrix-assisted laser desorption ionization. JOURNAL OF MASS SPECTROMETRY : JMS 2021; 56:e4664. [PMID: 33819368 DOI: 10.1002/jms.4664] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/19/2020] [Accepted: 09/24/2020] [Indexed: 06/12/2023]
Abstract
Matrix-assisted laser desorption ionization (MALDI) was introduced 35 years ago and has advanced from a general method for producing intact ions from large biomolecules to wide use in applications ranging from bacteria identification to tissue imaging. MALDI was enabled by the development of high energy pulsed lasers that create ions from solid samples for analysis by mass spectrometry. The original lasers used for MALDI were ultraviolet fixed-wavelength nitrogen and Nd:YAG lasers, and a number of additional laser sources have been subsequently introduced with wavelengths ranging from the infrared to the ultraviolet and pulse widths from nanosecond to femtosecond. Wavelength tunable sources have been employed both in the IR and UV, and repetition rates have increased from tens of Hz to tens of kHz as MALDI has moved into mass spectrometry imaging. Dual-pulse configurations have been implemented with two lasers directed at the target or with a second laser creating ions in the plume of desorbed material. This review provides a brief history of the use of lasers for ionization in mass spectrometry and describes the various types of lasers and configurations used for MALDI.
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Affiliation(s)
- Kermit K Murray
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana, USA
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McEwen CN, Inutan ED, Moreno-Pedraza A, Lu IC, Hoang K, Pophristic M, Trimpin S. Sublimation Driven Ionization for Use in Mass Spectrometry: Mechanistic Implications. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:114-123. [PMID: 33280376 DOI: 10.1021/jasms.0c00297] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Sublimation has been known at least since the middle ages. This process is frequently taught in schools through the use of phase diagrams. Astonishingly, such a well-known process appears to still harbor secrets. Under conditions in which compound sublimation occurs, gas-phase ions are frequently detected using mass spectrometry. This was exploited in matrix-assisted ionization in vacuum (vMAI) by adding analyte to subliming compounds used as matrices. Good vMAI matrices were those that ionize the added analyte with high sensitivity, but even matrices that fail this test often produce ions of likely matrix impurities suggesting that they may be good matrices for some compound types. We also show that binary matrices may be manipulated to provide desired properties such as fast analyses and improved sensitivity. These results imply that sublimation in some cases is more complicated than just molecules leaving a surface and that understanding the physical force responsible, and how the nonvolatile compound becomes charged, could lead to improved ionization efficiency for mass spectrometry. Here we provide insights into this process and an explanation of why this unexpected phenomenon has not previously been reported.
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Affiliation(s)
- Charles N McEwen
- University of the Sciences, Philadelphia, Pennsylvania 19104, United States
- MSTM, LLC, Newark, Delaware 19711, United States
| | - Ellen D Inutan
- MSTM, LLC, Newark, Delaware 19711, United States
- Mindanao State University Iligan Institute of Technology, Iligan City 9200, Philippines
| | | | - I-Chung Lu
- National Chung Hsing University, Taichung City, Taiwan 402
| | - Khoa Hoang
- MSTM, LLC, Newark, Delaware 19711, United States
| | | | - Sarah Trimpin
- MSTM, LLC, Newark, Delaware 19711, United States
- Wayne State University, Detroit, Michigan 48202, United States
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Trimpin S, Marshall DD, Karki S, Madarshahian S, Hoang K, Meher AK, Pophristic M, Richards AL, Lietz CB, Fischer JL, Elia EA, Wang B, Pagnotti VS, Lutomski CA, El-Baba TJ, Lu IC, Wager-Miller J, Mackie K, McEwen CN, Inutan ED. An overview of biological applications and fundamentals of new inlet and vacuum ionization technologies. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35 Suppl 1:e8829. [PMID: 32402102 DOI: 10.1002/rcm.8829] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 05/01/2020] [Accepted: 05/10/2020] [Indexed: 06/11/2023]
Abstract
RATIONALE The developments of new ionization technologies based on processes previously unknown to mass spectrometry (MS) have gained significant momentum. Herein we address the importance of understanding these unique ionization processes, demonstrate the new capabilities currently unmet by other methods, and outline their considerable analytical potential. METHODS The inlet and vacuum ionization methods of solvent-assisted ionization (SAI), matrix-assisted ionization (MAI), and laserspray ionization can be used with commercial and dedicated ion sources producing ions from atmospheric or vacuum conditions for analyses of a variety of materials including drugs, lipids, and proteins introduced from well plates, pipet tips and plate surfaces with and without a laser using solid or solvent matrices. Mass spectrometers from various vendors are employed. RESULTS Results are presented highlighting strengths relative to ionization methods of electrospray ionization (ESI) and matrix-assisted laser desorption/ionization. We demonstrate the utility of multi-ionization platforms encompassing MAI, SAI, and ESI and enabling detection of what otherwise is missed, especially when directly analyzing mixtures. Unmatched robustness is achieved with dedicated vacuum MAI sources with mechanical introduction of the sample to the sub-atmospheric pressure (vacuum MAI). Simplicity and use of a wide array of matrices are attained using a conduit (inlet ionization), preferably heated, with sample introduction from atmospheric pressure. Tissue, whole blood, urine (including mouse, chicken, and human origin), bacteria strains and chemical on-probe reactions are analyzed directly and, especially in the case of vacuum ionization, without concern of carryover or instrument contamination. CONCLUSIONS Examples are provided highlighting the exceptional analytical capabilities associated with the novel ionization processes in MS that reduce operational complexity while increasing speed and robustness, achieving mass spectra with low background for improved sensitivity, suggesting the potential of this simple ionization technology to drive MS into areas currently underserved, such as clinical and medical applications.
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Affiliation(s)
- Sarah Trimpin
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
- MS™, LLC, Newark, DE, 19711, USA
| | - Darrell D Marshall
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
- MS™, LLC, Newark, DE, 19711, USA
| | - Santosh Karki
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
- MS™, LLC, Newark, DE, 19711, USA
| | | | - Khoa Hoang
- MS™, LLC, Newark, DE, 19711, USA
- University of the Sciences, Philadelphia, PA, 19104, USA
| | - Anil K Meher
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
- MS™, LLC, Newark, DE, 19711, USA
| | - Milan Pophristic
- MS™, LLC, Newark, DE, 19711, USA
- University of the Sciences, Philadelphia, PA, 19104, USA
| | - Alicia L Richards
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | | | - Joshua L Fischer
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - Efstathios A Elia
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - Beixi Wang
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | | | - Corinne A Lutomski
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - Tarick J El-Baba
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - I-Chung Lu
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - James Wager-Miller
- Gill Center for Biomolecular Science and Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA
| | - Ken Mackie
- Gill Center for Biomolecular Science and Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA
| | - Charles N McEwen
- MS™, LLC, Newark, DE, 19711, USA
- University of the Sciences, Philadelphia, PA, 19104, USA
| | - Ellen D Inutan
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
- MS™, LLC, Newark, DE, 19711, USA
- Mindanao State University Iligan Institute of Technology, Iligan City, 9200, Philippines
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Inutan ED, Jarois DR, Lietz CB, El-Baba TJ, Elia EA, Karki S, Sampat AAS, Foley CD, Clemmer DE, Trimpin S. Comparison of gaseous ubiquitin ion structures obtained from a solid and solution matrix using ion mobility spectrometry/mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35 Suppl 1:e8793. [PMID: 32220130 DOI: 10.1002/rcm.8793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 03/24/2020] [Accepted: 03/24/2020] [Indexed: 06/10/2023]
Abstract
RATIONALE Examining surface protein conformations, and especially achieving this with spatial resolution, is an important goal. The recently discovered ionization processes offer spatial-resolution measurements similar to matrix-assisted laser desorption/ionization (MALDI) and produce charge states similar to electrospray ionization (ESI) extending higher-mass protein applications directly from surfaces on high-performance mass spectrometers. Studying a well-interrogated protein by ion mobility spectrometry-mass spectrometry (IMS-MS) to access effects on structures using a solid vs. solvent matrix may provide insights. METHODS Ubiquitin was studied by IMS-MS using new ionization processes with commercial and homebuilt ion sources and instruments (Waters SYNAPT G2(S)) and homebuilt 2 m drift-tube instrument; MS™ sources). Mass-to-charge and drift-time (td )-measurements are compared for ubiquitin ions obtained by inlet and vacuum ionization using laserspray ionization (LSI), matrix- (MAI) and solvent-assisted ionization (SAI), respectively, and compared with those from ESI under conditions that are most comparable. RESULTS Using the same solution conditions with SYNAPT G2(S) instruments, td -distributions of various ubiquitin charge states from MAI, LSI, and SAI are similar to those from ESI using a variety of solvents, matrices, extraction voltages, a laser, and temperature only, showing subtle differences in more compact features within the elongated distribution of structures. However, on a homebuilt drift-tube instrument, within the elongated distribution of structures, both similar and different td -distributions are observed for ubiquitin ions obtained by MAI and ESI. MAI-generated ions are frequently narrower in their td -distributions. CONCLUSIONS Direct comparisons between ESI and the new ionization methods operational directly from surfaces suggest that the protein in its solution structure prior to exposure to the ionization event is either captured (frozen out) at the time of crystallization, or that the protein in the solid matrix is associated with sufficient solvent to maintain the solution structure, or, alternatively, that the observed structures are those related to what occurs in the gas phase with ESI- or MAI-generated ions and not with the solution structures.
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Affiliation(s)
- Ellen D Inutan
- MSTM, LLC, Newark, DE, USA
- Department of Chemistry, Wayne State University, Detroit, MI, USA
- Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
| | - Dean R Jarois
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | | | - Tarick J El-Baba
- Department of Chemistry, Indiana University, Bloomington, IN, USA
| | | | - Santosh Karki
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | | | - Casey D Foley
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | - David E Clemmer
- Department of Chemistry, Indiana University, Bloomington, IN, USA
| | - Sarah Trimpin
- MSTM, LLC, Newark, DE, USA
- Department of Chemistry, Wayne State University, Detroit, MI, USA
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Banstola B, Murray KK. A nanoparticle co-matrix for multiple charging in matrix-assisted laser desorption ionization imaging of tissue. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35 Suppl 1:e8424. [PMID: 30822818 DOI: 10.1002/rcm.8424] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 01/07/2019] [Accepted: 02/24/2019] [Indexed: 06/09/2023]
Abstract
RATIONALE A two-component matrix of 2-nitrophloroglucinol (2-NPG) and silica nanoparticles was used for matrix-assisted laser desorption ionization (MALDI) mass spectrometry imaging of high-charge-state biomolecules in tissue. Potential advantages include increased effective mass range and efficiency of fragmentation. METHODS A mixture of 2-NPG matrix and silica nanoparticles was applied to cyrosectioned 10 μm thick mouse brain tissue. The mixture was pipetted onto the tissue for profiling and sprayed for tissue imaging. MALDI images were obtained under high vacuum in a commercial time-of-flight mass spectrometer. RESULTS The combined 2-NPG and nanoparticle matrix produced highly charged ions from tissue with high-vacuum MALDI. Nanoparticles of 20, 70, 400, and 1000 nm in diameter were tested, the 20 nm particles producing the highest charge states. Images of mouse brain tissue obtained from highly charged ions show similar spatial localization. CONCLUSIONS The combined 2-NPG and nanoparticle matrix produces highly charged ions from tissue through a mechanism that may rely on the high surface area of the particles which can dry the tissue, and their ability to bind analyte molecules thereby assisting in crystal formation and production of multiply charged ions on laser irradiation.
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Affiliation(s)
- Bijay Banstola
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Kermit K Murray
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA
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Lee C, Inutan ED, Chen JL, Mukeku MM, Weidner SM, Trimpin S, Ni CK. Toward understanding the ionization mechanism of matrix-assisted ionization using mass spectrometry experiment and theory. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35 Suppl 1:e8382. [PMID: 30623523 DOI: 10.1002/rcm.8382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 01/03/2019] [Indexed: 06/09/2023]
Abstract
RATIONALE Matrix-assisted ionization (MAI) mass spectrometry does not require voltages, a laser beam, or added heat to initiate ionization, but it is strongly dependent on the choice of matrix and the vacuum conditions. High charge state distributions of nonvolatile analyte ions produced by MAI suggest that the ionization mechanism may be similar to that of electrospray ionization (ESI), but different from matrix-assisted laser desorption/ionization (MALDI). While significant information is available for MAI using mass spectrometers operating at atmospheric and intermediate pressure, little is known about the mechanism at high vacuum. METHODS Eleven MAI matrices were studied on a high-vacuum time-of-flight (TOF) mass spectrometer using a 266 nm pulsed laser beam under otherwise typical MALDI conditions. Detailed comparisons with the commonly used MALDI matrices and theoretical prediction were made for 3-nitrobenzonitrile (3-NBN), which is the only MAI matrix that works well in high vacuum when irradiated with a laser. RESULTS Screening of MAI matrices with good absorption at 266 nm but with various degrees of volatility and laser energies suggests that volatility and absorption at the laser wavelength may be necessary, but not sufficient, criteria to explain the formation of multiply charged analyte ions. 3-NBN produces intact, highly charged ions of nonvolatile analytes in high-vacuum TOF with the use of a laser, demonstrating that ESI-like ions can be produced in high vacuum. Theoretical calculations and mass spectra suggest that thermally induced proton transfer, which is the major ionization mechanism in MALDI, is not important with the 3-NBN matrix at 266 nm laser wavelength. 3-NBN:analyte crystal morphology is, however, important in ion generation in high vacuum. CONCLUSIONS The 3-NBN MAI matrix produces intact, highly charged ions of nonvolatile compounds in high-vacuum TOF mass spectrometers with the aid of ablation and/or heating by laser irradiation, and shows a different ionization mechanism from that of typical MALDI matrices.
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Affiliation(s)
- Chuping Lee
- Department of Chemistry, Wayne State University, Detroit, MI, USA
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
| | - Ellen D Inutan
- Department of Chemistry, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
| | - Jien Lian Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
| | - Mutanu M Mukeku
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | - Steffen M Weidner
- Bundesanstalt für Materialforschung und-prüfung, Richard-Willstätter-Straße 11, 12489, Berlin, Germany
| | - Sarah Trimpin
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | - Chi-Kung Ni
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
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11
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Chen YH, Lu IC. Novel ion source for a portable mass spectrometer. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35 Suppl 1:e8503. [PMID: 31197905 DOI: 10.1002/rcm.8503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/29/2019] [Accepted: 05/29/2019] [Indexed: 06/09/2023]
Affiliation(s)
- Yi-Hsin Chen
- Department of Chemistry, National Chung Hsing University, Taichung, Taiwan
| | - I-Chung Lu
- Department of Chemistry, National Chung Hsing University, Taichung, Taiwan
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Inutan ED, Meher AK, Karki S, Fischer JL, Imperial LF, Foley CD, Jarois DR, El-Baba TJ, Lutomski CA, Trimpin S. New mass spectrometry concepts for characterization of synthetic polymers and additives. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34 Suppl 2:e8768. [PMID: 32107802 DOI: 10.1002/rcm.8768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/17/2020] [Accepted: 02/19/2020] [Indexed: 06/10/2023]
Abstract
RATIONALE New ionization processes have been developed for biological mass spectrometry (MS) in which the matrix lifts the nonvolatile analyte into the gas phase as ions without any additional energy input. We rationalized that additional fundamental knowledge is needed to assess analytical utility for the field of synthetic polymers and additives. METHODS Different mass spectrometers (Thermo Orbitrap (Q-)Exactive (Focus); Waters SYNAPT G2(S)) were employed. The formation of multiply charged polymer ions upon exposure of the matrix/analyte(/salt) sample to sub-atmospheric pressure directly from the solid state and surfaces facilitates the use of advanced mass spectrometers for detection of polymeric materials including consumer products (e.g., gum). RESULTS Astonishingly, using nothing more than a small molecule matrix compound (e.g., 2-methyl-2-nitropropane-1,3-diol or 3-nitrobenzonitrile) and a salt (e.g., mono- or divalent cation(s)), such samples upon exposure to sub-atmospheric pressure transfer nonvolatile polymers and nonvolatile salts into the gas phase as multiply charged ions. These successes contradict the conventional understanding of ionization in MS, because can nonvolatile polymers be lifted in the gas phase as ions not only by as little as a volatile matrix but also by the salt required for ionizing the analyte through noncovalent metal cation adduction(s). Prototype vacuum matrix-assisted ionization (vMAI) and automated sources using a contactless approach are demonstrated for direct analyses of synthetic polymers and plasticizers, minimizing the risk of contamination using direct sample introduction into the mass spectrometer vacuum. CONCLUSIONS Direct ionization methods from surfaces without the need of high voltage, a laser, or even applied heat are demonstrated for characterization of detailed materials using (ultra)high-resolution and accurate mass measurements enabled by the multiply charged ions extending the mass range of high-performance mass spectrometers and use of a split probe sample introduction device. Our vision is that, with further development of fundamentals and dedicated sources, both spatial- and temporal-resolution measurements are within reach if sensitivity is addressed for decreasing sample-size measurements.
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Affiliation(s)
- Ellen D Inutan
- Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
- Department of Chemistry, Wayne State University, Detroit, MI, USA
- MS™, LLC, Newark, DE, USA
| | - Anil K Meher
- Department of Chemistry, Wayne State University, Detroit, MI, USA
- MS™, LLC, Newark, DE, USA
| | - Santosh Karki
- Department of Chemistry, Wayne State University, Detroit, MI, USA
- MS™, LLC, Newark, DE, USA
| | - Joshua L Fischer
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | | | - Casey D Foley
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | - Dean R Jarois
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | - Tarick J El-Baba
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | | | - Sarah Trimpin
- Department of Chemistry, Wayne State University, Detroit, MI, USA
- MS™, LLC, Newark, DE, USA
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13
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Trimpin S. Novel ionization processes for use in mass spectrometry: 'Squeezing' nonvolatile analyte ions from crystals and droplets. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2019; 33 Suppl 3:96-120. [PMID: 30138957 DOI: 10.1002/rcm.8269] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/29/2018] [Accepted: 08/15/2018] [Indexed: 05/25/2023]
Abstract
Together with my group and collaborators, I have been fortunate to have had a key role in the discovery of new ionization processes that we developed into new flexible, sensitive, rapid, reliable, and robust ionization technologies and methods for use in mass spectrometry (MS). Our current research is focused on how best to understand, improve, and use these novel ionization processes which convert volatile and nonvolatile compounds from solids or liquids into gas-phase ions for analysis by MS using e.g. mass-selected fragmentation and ion mobility spectrometry to provide reproducible, accurate, and improved mass and drift time resolution. In my view, the apex was the discovery of vacuum matrix-assisted ionization (vMAI) in 2012 on an intermediate pressure matrix-assisted laser desorption/ionization (MALDI) source without the use of a laser, high voltages, or any other added energy. Only exposure of the matrix:analyte to the sub-atmospheric pressure of the mass spectrometer was necessary to initiate ionization. These findings were initially rejected by three different scientific journals, with comments related to 'how can this work?', 'where do the charges come from?', and 'it is not analytically useful'. Meanwhile, we and others have demonstrated analytical utility without a complete understanding of the mechanism. In reality, MALDI and electrospray ionization are widely used in science and their mechanisms are still controversially discussed despite use and optimization of now 30 years. This Perspective covers the applications and mechanistic aspects of the novel ionization processes for use in MS that guided us in instrument developments, and provides our perspective on how they relate to traditional ionization processes.
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Affiliation(s)
- Sarah Trimpin
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
- Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI, 48201, USA
- MSTM, LLC, Newark, DE, 19711, USA
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14
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Trimpin S, Inutan ED, Karki S, Elia EA, Zhang WJ, Weidner SM, Marshall DD, Hoang K, Lee C, Davis ETJ, Smith V, Meher AK, Cornejo MA, Auner GW, McEwen CN. Fundamental Studies of New Ionization Technologies and Insights from IMS-MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:1133-1147. [PMID: 31062287 DOI: 10.1007/s13361-019-02194-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/13/2019] [Accepted: 03/13/2019] [Indexed: 06/09/2023]
Abstract
Exceptional ion mobility spectrometry mass spectrometry (IMS-MS) developments by von Helden, Jarrold, and Clemmer provided technology that gives a view of chemical/biological compositions previously not achievable. The ionization method of choice used with IMS-MS has been electrospray ionization (ESI). In this special issue contribution, we focus on fundamentals of heretofore unprecedented means for transferring volatile and nonvolatile compounds into gas-phase ions singly and multiply charged. These newer ionization processes frequently lead to different selectivity relative to ESI and, together with IMS-MS, may provide a more comprehensive view of chemical compositions directly from their original environment such as surfaces, e.g., tissue. Similarities of results using solvent- and matrix-assisted ionization are highlighted, as are differences between ESI and the inlet ionization methods, especially with mixtures such as bacterial extracts. Selectivity using different matrices is discussed, as are results which add to our fundamental knowledge of inlet ionization as well as pose additional avenues for inquiry. IMS-MS provides an opportunity for comparison studies relative to ESI and will prove valuable using the new ionization technologies for direct analyses. Our hypothesis is that some ESI-IMS-MS applications will be replaced by the new ionization processes and by understanding mechanistic aspects to aid enhanced source and method developments this will be hastened.
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Affiliation(s)
- Sarah Trimpin
- Department of Chemistry, Wayne State University, Detroit, MI, USA.
- Cardiovascular Research Institute, School of Medicine, Wayne State University, Detroit, MI, USA.
- MSTM, LLC, Newark, DE, USA.
| | - Ellen D Inutan
- Department of Chemistry, Wayne State University, Detroit, MI, USA
- MSTM, LLC, Newark, DE, USA
- Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
| | - Santosh Karki
- Department of Chemistry, Wayne State University, Detroit, MI, USA
- MSTM, LLC, Newark, DE, USA
| | | | - Wen-Jing Zhang
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | - Steffen M Weidner
- Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany
| | - Darrell D Marshall
- Department of Chemistry, Wayne State University, Detroit, MI, USA
- MSTM, LLC, Newark, DE, USA
| | - Khoa Hoang
- University of the Sciences, Philadelphia, PA, USA
| | - Chuping Lee
- Department of Chemistry, Wayne State University, Detroit, MI, USA
- MSTM, LLC, Newark, DE, USA
| | - Eric T J Davis
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | | | - Anil K Meher
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | - Mario A Cornejo
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | - Gregory W Auner
- Department of Surgery, School of Medicine, Wayne State University, Detroit, MI, USA
| | - Charles N McEwen
- MSTM, LLC, Newark, DE, USA
- University of the Sciences, Philadelphia, PA, USA
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Banstola B, Szot CW, Deenamulla Kankanamalage AP, Murray KK. Piezoelectric matrix-assisted ionization. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2019; 25:202-207. [PMID: 30526027 DOI: 10.1177/1469066718816696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We have developed a new actuation method for matrix-assisted ionization with good temporal and spatial resolution using piezoelectric cantilever. A strike from the piezoelectric bimorph cantilever on a thin metal foil was used to remove materials deposited on the opposite side facing the mass spectrometer inlet. Highly charged ions of peptides and proteins were generated from dried droplet deposits and sampled into the inlet of the mass spectrometer. A lateral resolution of 1 mm was obtained with the piezoelectric sampling configuration. Singly charged lipids and gangliosides were detected from tissue with piezoelectric matrix-assisted ionization using a silica nanoparticle co-matrix.
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Affiliation(s)
- Bijay Banstola
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Carson W Szot
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana, USA
| | | | - Kermit K Murray
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana, USA
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