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Hanley L, Wickramasinghe R, Yung YP. Laser Desorption Combined with Laser Postionization for Mass Spectrometry. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2019; 12:225-245. [PMID: 30786215 DOI: 10.1146/annurev-anchem-061318-115447] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Lasers with pulse lengths from nanoseconds to femtoseconds and wavelengths from the mid-infrared to extreme ultraviolet (UV) have been used for desorption or ablation in mass spectrometry. Such laser sampling can often benefit from the addition of a second laser for postionization of neutrals. The advantages offered by laser postionization include the ability to forego matrix application, high lateral resolution, decoupling of ionization from desorption, improved analysis of electrically insulating samples, and potential for high sensitivity and depth profiling while minimizing differential detection. A description of postionization by vacuum UV radiation is followed by a consideration of multiphoton, short pulse, and other postionization strategies. The impacts of laser pulse length and wavelength are considered for laser desorption or laser ablation at low pressures. Atomic and molecular analysis via direct laser desorption/ionization using near-infrared ultrashort pulses is described. Finally, the postionization of clusters, the role of gaseous collisions, sampling at ambient pressure, atmospheric pressure photoionization, and the addition of UV postionization to MALDI are considered.
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Affiliation(s)
- Luke Hanley
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, USA;
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2
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Komorek R, Xu B, Yao J, Ablikim U, Troy TP, Kostko O, Ahmed M, Yu XY. Enabling liquid vapor analysis using synchrotron VUV single photon ionization mass spectrometry with a microfluidic interface. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:115105. [PMID: 30501361 DOI: 10.1063/1.5048315] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 10/19/2018] [Indexed: 06/09/2023]
Abstract
Vacuum ultraviolet (VUV) single photon ionization mass spectrometry (SPI-MS) is a vacuum-based technique typically used for the analysis of gas phase and solid samples, but not for liquids due to the challenge in introducing volatile liquids in a vacuum. Here we present the first demonstration of in situ liquid analysis by integrating the System for Analysis at the Liquid Vacuum Interface (SALVI) microfluidic reactor into VUV SPI-MS. Four representative volatile organic compound (VOC) solutions were used to illustrate the feasibility of liquid analysis. Our results show the accurate mass identification of the VOC molecules and the reliable determination of appearance energy that is consistent with ionization energy for gaseous species in the literature as reported. This work validates that the vacuum-compatible SALVI microfluidic interface can be utilized at the synchrotron beamline and enable the in situ study of gas-phase molecules evaporating off the surface of a liquid, which holds importance in the study of condensed matter chemistry.
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Affiliation(s)
- R Komorek
- Atmospheric Sciences and Global Change Division, PNNL, Richland, Washington 99354, USA
| | - B Xu
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - J Yao
- Atmospheric Sciences and Global Change Division, PNNL, Richland, Washington 99354, USA
| | - U Ablikim
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - T P Troy
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - O Kostko
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M Ahmed
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - X Y Yu
- Atmospheric Sciences and Global Change Division, PNNL, Richland, Washington 99354, USA
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3
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Lu Q, Hu Y, Chen J, Jin S. Laser Desorption Postionization Mass Spectrometry Imaging of Folic Acid Molecules in Tumor Tissue. Anal Chem 2017; 89:8238-8243. [DOI: 10.1021/acs.analchem.7b00140] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Qiao Lu
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, P. R. China
| | - Yongjun Hu
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, P. R. China
| | - Jiaxin Chen
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, P. R. China
| | - Shan Jin
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, P. R. China
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4
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Kostko O, Bandyopadhyay B, Ahmed M. Vacuum Ultraviolet Photoionization of Complex Chemical Systems. Annu Rev Phys Chem 2016; 67:19-40. [DOI: 10.1146/annurev-physchem-040215-112553] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Oleg Kostko
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720;
| | - Biswajit Bandyopadhyay
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720;
| | - Musahid Ahmed
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720;
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5
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Molecular excitation and relaxation of extreme ultraviolet lithography photoresists. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/b978-0-08-100354-1.00002-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
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6
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Akhmetov A, Bhardwaj C, Hanley L. Laser desorption postionization mass spectrometry imaging of biological targets. Methods Mol Biol 2015; 1203:185-94. [PMID: 25361678 DOI: 10.1007/978-1-4939-1357-2_18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Laser desorption photoionization mass spectrometry (LDPI-MS) utilizes two separate light sources for desorption and photoionization of species from a solid surface. This technique has been applied to study a wide variety of molecular analytes in biological systems, but is not yet available in commercial instruments. For this reason, a generalized protocol is presented here for the use of LDPI-MS imaging to detect small molecules within intact biological samples. Examples are provided here for LDPI-MS imaging of an antibiotic within a tooth root canal and a metabolite within a coculture bacterial biofilm.
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Affiliation(s)
- Artem Akhmetov
- Department of Chemistry, University of Illinois at Chicago, MC 111, 845 W. Taylor St., 4500 SES, Chicago, IL, 60607-7061, USA
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7
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Cui Y, Veryovkin IV, Majeski MW, Cavazos DR, Hanley L. High Lateral Resolution vs Molecular Preservation in near-IR fs-Laser Desorption Postionization Mass Spectrometry. Anal Chem 2014; 87:367-71. [DOI: 10.1021/ac5041154] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yang Cui
- Department
of Chemistry, University of Illinois at Chicago, MC 111, Chicago, Illinois 60607, United States
| | - Igor V. Veryovkin
- Department
of Chemistry, University of Illinois at Chicago, MC 111, Chicago, Illinois 60607, United States
| | - Michael W. Majeski
- Department
of Chemistry, University of Illinois at Chicago, MC 111, Chicago, Illinois 60607, United States
| | - Daniel R. Cavazos
- Department
of Chemistry, University of Illinois at Chicago, MC 111, Chicago, Illinois 60607, United States
| | - Luke Hanley
- Department
of Chemistry, University of Illinois at Chicago, MC 111, Chicago, Illinois 60607, United States
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8
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Liu SY, Shawkey MD, Parkinson D, Troy TP, Ahmed M. Elucidation of the chemical composition of avian melanin. RSC Adv 2014. [DOI: 10.1039/c4ra06606e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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9
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Bhardwaj C, Cui Y, Hofstetter T, Liu SY, Bernstein HC, Carlson RP, Ahmed M, Hanley L. Differentiation of microbial species and strains in coculture biofilms by multivariate analysis of laser desorption postionization mass spectra. Analyst 2014; 138:6844-51. [PMID: 24067765 DOI: 10.1039/c3an01389h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
7.87 to 10.5 eV vacuum ultraviolet (VUV) photon energies were used in laser desorption postionization mass spectrometry (LDPI-MS) to analyze biofilms comprised of binary cultures of interacting microorganisms. The effect of photon energy was examined using both tunable synchrotron and laser sources of VUV radiation. Principal components analysis (PCA) was applied to the MS data to differentiate species in Escherichia coli-Saccharomyces cerevisiae coculture biofilms. PCA of LDPI-MS also differentiated individual E. coli strains in a biofilm comprised of two interacting gene deletion strains, even though these strains differed from the wild type K-12 strain by no more than four gene deletions each out of approximately 2000 genes. PCA treatment of 7.87 eV LDPI-MS data separated the E. coli strains into three distinct groups, two "pure" groups, and a mixed region. Furthermore, the "pure" regions of the E. coli cocultures showed greater variance by PCA at 7.87 eV photon energies compared to 10.5 eV radiation. This is consistent with the expectation that the 7.87 eV photoionization selects a subset of low ionization energy analytes while 10.5 eV is more inclusive, detecting a wider range of analytes. These two VUV photon energies therefore give different spreads via PCA and their respective use in LDPI-MS constitute an additional experimental parameter to differentiate strains and species.
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Affiliation(s)
- Chhavi Bhardwaj
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607-7061, USA.
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Tia M, Cunha de Miranda B, Daly S, Gaie-Levrel F, Garcia GA, Nahon L, Powis I. VUV photodynamics and chiral asymmetry in the photoionization of gas phase alanine enantiomers. J Phys Chem A 2014; 118:2765-79. [PMID: 24654892 DOI: 10.1021/jp5016142] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The valence shell photoionization of the simplest proteinaceous chiral amino acid, alanine, is investigated over the vacuum ultraviolet region from its ionization threshold up to 18 eV. Tunable and variable polarization synchrotron radiation was coupled to a double imaging photoelectron/photoion coincidence (i(2)PEPICO) spectrometer to produce mass-selected threshold photoelectron spectra and derive the state-selected fragmentation channels. The photoelectron circular dichroism (PECD), an orbital-sensitive, conformer-dependent chiroptical effect, was also recorded at various photon energies and compared to continuum multiple scattering calculations. Two complementary vaporization methods-aerosol thermodesorption and a resistively heated sample oven coupled to an adiabatic expansion-were applied to promote pure enantiomers of alanine into the gas phase, yielding neutral alanine with different internal energy distributions. A comparison of the photoelectron spectroscopy, fragmentation, and dichroism measured for each of the vaporization methods was rationalized in terms of internal energy and conformer populations and supported by theoretical calculations. The analytical potential of the so-called PECD-PICO detection technique-where the electron spectroscopy and circular dichroism can be obtained as a function of mass and ion translational energy-is underlined and applied to characterize the origin of the various species found in the experimental mass spectra. Finally, the PECD findings are discussed within an astrochemical context, and possible implications regarding the origin of biomolecular asymmetry are identified.
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Affiliation(s)
- Maurice Tia
- Synchrotron SOLEIL, l'Orme des Merisiers, Saint Aubin BP 48, 91192 Gif sur Yvette Cedex, France
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11
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Bhardwaj C, Hanley L. Ion sources for mass spectrometric identification and imaging of molecular species. Nat Prod Rep 2014; 31:756-67. [PMID: 24473154 DOI: 10.1039/c3np70094a] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Covering: 2013 The ability to transfer molecular species to the gas phase and ionize them is central to the study of natural products and other molecular species by mass spectrometry (MS). MS-based strategies in natural products have focused on a few established ion sources, such as electron impact and electrospray ionization. However, a variety of other ion sources are either currently in use to evaluate natural products or show significant future promise. This review discusses these various ion sources in the context of other articles in this special issue, but is also applicable to other fields of analysis, including materials science. Ion sources are grouped based on the current understanding of their predominant ion formation mechanisms. This broad overview groups ion sources into the following categories: electron ionization and single photon ionization; chemical ionization-like and plasma-based; electrospray ionization; and, laser desorption-based. Laser desorption-based methods are emphasized with specific examples given for laser desorption postionization sources and their use in the analysis of intact microbial biofilms. Brief consideration is given to the choice of ion source for various sample types and analyses, including MS imaging.
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Affiliation(s)
- Chhavi Bhardwaj
- Department of Chemistry, University of Illinois at Chicago, mc 111, Chicago, IL 60607-7061.
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12
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Schwell M, Hochlaf M. Photoionization Spectroscopy of Nucleobases and Analogues in the Gas Phase Using Synchrotron Radiation as Excitation Light Source. Top Curr Chem (Cham) 2014; 355:155-208. [DOI: 10.1007/128_2014_550] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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13
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Liu SY, Kleber M, Takahashi LK, Nico P, Keiluweit M, Ahmed M. Synchrotron-Based Mass Spectrometry to Investigate the Molecular Properties of Mineral–Organic Associations. Anal Chem 2013; 85:6100-6. [DOI: 10.1021/ac400976z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Suet Yi Liu
- Chemical Science
Division, Lawrence Berkeley National Laboratory, Berkeley, California,
United States
| | - Markus Kleber
- Department
of Crop and Soil
Science, Oregon State University, Corvallis,
Oregon, United States
| | - Lynelle K. Takahashi
- Chemical Science
Division, Lawrence Berkeley National Laboratory, Berkeley, California,
United States
| | - Peter Nico
- Earth
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California,
United States
| | - Marco Keiluweit
- Department
of Crop and Soil
Science, Oregon State University, Corvallis,
Oregon, United States
- Chemical
Sciences Division, Lawrence Livermore National Laboratory, Livermore,
California, United States
| | - Musahid Ahmed
- Chemical Science
Division, Lawrence Berkeley National Laboratory, Berkeley, California,
United States
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14
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Schmid P, Stöhr F, Arndt M, Tüxen J, Mayor M. Single-photon ionization of organic molecules beyond 10 kDa. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2013; 24:602-8. [PMID: 23444050 PMCID: PMC3622019 DOI: 10.1007/s13361-012-0551-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 11/27/2012] [Accepted: 11/30/2012] [Indexed: 05/15/2023]
Abstract
The volatilization and soft ionization of complex neutral macromolecules at low energies has remained an outstanding challenge for several decades. Most volatilization techniques in mass spectrometry produce ions already in the source and most of them lead to particle velocities in excess of several hundred meters per second. For many macromolecules, post-ionization is inefficient since electronic or optical excitations can be followed by competing non-ionizing internal conversion, electron recapture, or fragmentation processes. Here, we explore the laser-assisted volatilization of neutral perfluoroalkyl-functionalized tetraphenylporphyrins as well as their single-photon ionization using vacuum ultraviolet (VUV) light at 157 nm. A systematic investigation of the ionization curves allows us to determine the molecular velocity distribution and ionization cross sections. We demonstrate the detection of single photon ionized intact organic molecules in excess of 10 kDa from a slow molecular beam.
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Affiliation(s)
- Philipp Schmid
- University of Vienna, Faculty of Physics, VCQ Vienna, Austria
| | - Frederik Stöhr
- University of Vienna, Faculty of Physics, VCQ Vienna, Austria
| | - Markus Arndt
- University of Vienna, Faculty of Physics, VCQ Vienna, Austria
| | - Jens Tüxen
- Department of Chemistry, University of Basel, Basel, Switzerland
| | - Marcel Mayor
- Department of Chemistry, University of Basel, Basel, Switzerland
- Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology, Karlsruhe, Germany
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15
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Blaze MMT, Akhmetov A, Aydin B, Edirisinghe PD, Uygur G, Hanley L. Quantification of antibiotic in biofilm-inhibiting multilayers by 7.87 eV laser desorption postionization MS imaging. Anal Chem 2012; 84:9410-5. [PMID: 23017064 PMCID: PMC3491138 DOI: 10.1021/ac302230e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The potential of laser desorption postionization mass spectrometry (LDPI-MS) imaging for small molecule quantification is demonstrated here. The N-methylpiperazine acetamide (MPA) of ampicillin was adsorbed into polyelectrolyte multilayer surface coatings composed of chitosan and alginate, both high molecular weight biopolymers. These MPA-ampicillin spiked multilayers were then shown to inhibit the growth of Enterococcus faecalis biofilms that play a role in early stage infection of implanted medical devices. Finally, LDPI-MS imaging using 7.87 eV single-photon ionization was found to detect MPA-ampicillin within the multilayers before and after biofilm growth with limits of quantification and detection of 0.6 and 0.3 nmol, respectively. The capabilities of LDPI-MS imaging for small molecule quantification are compared to those of MALDI-MS. Furthermore, these results indicate that 7.87 eV LDPI-MS imaging should be applicable to quantification of a range of small molecular species on a variety of complex organic and biological surfaces. Finally, while MS imaging for quantification was demonstrated here using LDPI, it is a generally useful strategy that can be applied to other methods.
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Affiliation(s)
- Melvin M. T. Blaze
- Department of Chemistry, MC 111, University of Illinois at Chicago, Chicago, IL 60607
| | - Artem Akhmetov
- Department of Chemistry, MC 111, University of Illinois at Chicago, Chicago, IL 60607
| | - Berdan Aydin
- Department of Chemistry, MC 111, University of Illinois at Chicago, Chicago, IL 60607
| | | | - Gulsah Uygur
- Department of Chemistry, MC 111, University of Illinois at Chicago, Chicago, IL 60607
| | - Luke Hanley
- Department of Chemistry, MC 111, University of Illinois at Chicago, Chicago, IL 60607
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16
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Bhardwaj C, Moore JF, Cui Y, Gasper GL, Bernstein HC, Carlson RP, Hanley L. Laser desorption VUV postionization MS imaging of a cocultured biofilm. Anal Bioanal Chem 2012; 405:6969-77. [PMID: 23052888 DOI: 10.1007/s00216-012-6454-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 09/14/2012] [Accepted: 09/24/2012] [Indexed: 10/27/2022]
Abstract
Laser desorption postionization mass spectrometry (LDPI-MS) imaging is demonstrated with a 10.5 eV photon energy source for analysis and imaging of small endogenous molecules within intact biofilms. Biofilm consortia comprised of a synthetic Escherichia coli K12 coculture engineered for syntrophic metabolite exchange are grown on membranes and then used to test LDPI-MS analysis and imaging. Both E. coli strains displayed many similar peaks in LDPI-MS up to m/z 650, although some observed differences in peak intensities were consistent with the appearance of byproducts preferentially expressed by one strain. The relatively low mass resolution and accuracy of this specific LDPI-MS instrument prevented definitive assignment of species to peaks, but strategies are discussed to overcome this shortcoming. The results are also discussed in terms of desorption and ionization issues related to the use of 10.5 eV single-photon ionization, with control experiments providing additional mechanistic information. Finally, 10.5 eV LDPI-MS was able to collect ion images from intact, electrically insulating biofilms at ~100 μm spatial resolution. Spatial resolution of ~20 μm was possible, although a relatively long acquisition time resulted from the 10 Hz repetition rate of the single-photon ionization source.
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Affiliation(s)
- Chhavi Bhardwaj
- Department of Chemistry, MC 111, University of Illinois at Chicago, Chicago, IL 60607-7061, USA
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17
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Cui Y, Moore JF, Milasinovic S, Liu Y, Gordon RJ, Hanley L. Depth profiling and imaging capabilities of an ultrashort pulse laser ablation time of flight mass spectrometer. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:093702. [PMID: 23020378 PMCID: PMC3461015 DOI: 10.1063/1.4750974] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 08/22/2012] [Indexed: 06/01/2023]
Abstract
An ultrafast laser ablation time-of-flight mass spectrometer (AToF-MS) and associated data acquisition software that permits imaging at micron-scale resolution and sub-micron-scale depth profiling are described. The ion funnel-based source of this instrument can be operated at pressures ranging from 10(-8) to ~0.3 mbar. Mass spectra may be collected and stored at a rate of 1 kHz by the data acquisition system, allowing the instrument to be coupled with standard commercial Ti:sapphire lasers. The capabilities of the AToF-MS instrument are demonstrated on metal foils and semiconductor wafers using a Ti:sapphire laser emitting 800 nm, ~75 fs pulses at 1 kHz. Results show that elemental quantification and depth profiling are feasible with this instrument.
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Affiliation(s)
- Yang Cui
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, USA
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18
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Ghosh D, Golan A, Takahashi LK, Krylov AI, Ahmed M. A VUV Photoionization and Ab Initio Determination of the Ionization Energy of a Gas-Phase Sugar (Deoxyribose). J Phys Chem Lett 2012; 3:97-101. [PMID: 26701259 DOI: 10.1021/jz201446r] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The ionization energy of gas-phase deoxyribose was determined using tunable vacuum ultraviolet synchrotron radiation coupled to an effusive thermal source. Adiabatic and vertical ionization energies of the ground and first four excited states of α-pyranose, the structure that dominates in the gas phase, were calculated using high-level electronic structure methods. An appearance energy of 9.1(±0.05) eV was recorded, which agrees reasonably well with a theoretical value of 8.8 eV for the adiabatic ionization energy. A clear picture of the dissociative photoionization dynamics of deoxyribose emerges from the fragmentation pattern recorded using mass spectrometry and from ab initio molecular dynamics calculations. The experimental threshold 9.4 (±0.05) eV for neutral water elimination upon ionization is captured well in the calculations, and qualitative insights are provided by molecular orbital analysis and molecular dynamics snapshots along the reaction coordinate.
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Affiliation(s)
- Debashree Ghosh
- Department of Chemistry, University of Southern California , Los Angeles, California 90089-0482, United States
| | - Amir Golan
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Lynelle K Takahashi
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
- Department of Chemistry, University of California at Berkeley , Berkeley, California 94720, United States
| | - Anna I Krylov
- Department of Chemistry, University of Southern California , Los Angeles, California 90089-0482, United States
| | - Musahid Ahmed
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
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