1
|
Maechler L, Fillipov I, Derrick PJ. Unveiling the intricacies of the curved-field ion mirror. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2015; 21:115-123. [PMID: 26307692 DOI: 10.1255/ejms.1352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In time-of-flight (ToF) mass spectrometry, non-linear ion mirrors, i.e. mirrors that produce a non-linear potential in which the ions fly, can focus ions exhibiting a very broad kinetic energy distribution. Besides the quadratic potential, the so-called curved field has been used in mirrors as a non-linear potential over the past 20 years. The curved field has, however, only been loosely defined. The focusing properties of the curved field appear to have never been mathematically investigated and explained. In this work, we put forward a rigid definition of the curved field and investigate the properties of it in terms of focusing and transmission. This rigid definition shows the curved field as a two-parameter function for a given mirror length and maximum potential, which can be optimized in terms of ToF distribution/resolution. Such an optimization was performed in one- dimension (1D) by solving the ToF integral equation numerically. The characteristics of optimized configurations arrived at through a comparison with mirrors with polynomial distance-potential relationships are assessed. These optimised solutions cannot be approximated in 1D by a common set of polynomial terms. There are optimised configurations affording ideal energy focussing, but on closer inspection, these potential distributions are found to be, in fact, quadratic potentials. There are other optimised solutions that afford good energy focussing in cases of there being significant field-free regions between the source/detector and the entrance to the mirror. Some of these configurations are approximated by a linear plus a quadratic term, others need higher-order terms to be approximated. To facilitate 3D investigation, the optimised solutions in 1D were used to set the initial voltages on electrodes in a rotationally symmetric mirror, which was modelled with the computer package SIMION 8.0. The SIMION ion-flight simulations revealed that the other optimised solutions with higher-order terms have the disadvantage of lowering the transmittance. That is to say, in 3D the configurations of the curved field, which give good resolution and transmittance with field- free regions between source/detector and mirror, can all be approximated by a potential consisting of a linear plus a quadratic term.
Collapse
Affiliation(s)
- Lars Maechler
- Ion Innovations Laboratory and Department of Physics, The University of Auckland, Auckland, New Zealand.
| | - Igor Fillipov
- Ion Innovations Laboratory and Department of Physics, The University of Auckland, Auckland, New Zealand.
| | - Peter J Derrick
- Io n Innovations Laboratory and Department of Physics, The University of Auckland, Auckland, New Zealand.
| |
Collapse
|
2
|
Cotter RJ. High energy collisions on tandem time-of-flight mass spectrometers. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2013; 24:657-74. [PMID: 23519928 PMCID: PMC3664224 DOI: 10.1007/s13361-012-0518-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 08/29/2012] [Accepted: 09/07/2012] [Indexed: 05/15/2023]
Abstract
Long before the introduction of matrix-assisted laser desorption/ionization (MALDI), electrospray ionization (ESI), Orbitraps, and any of the other tools that are now used ubiquitously for proteomics and metabolomics, the highest performance mass spectrometers were sector instruments, providing high resolution mass measurements by combining an electrostatic energy analyzer (E) with a high field magnet (B). In its heyday, the four sector mass spectrometer (or EBEB) was the crown jewel, providing the highest performance tandem mass spectrometry using single, high energy collisions to induce fragmentation. During a time in which quadrupole and tandem triple quadrupole instruments were also enjoying increased usage and popularity, there were, nonetheless, some clear advantages for sectors over their low collision energy counterparts. Time-of-flight (TOF) mass spectrometers are high voltage, high vacuum instruments that have much in common with sectors and have inspired the development of tandem instruments exploiting single high energy collisions. In this retrospective, we recount our own journey to produce high performance TOFs and tandem TOFs, describing the basic theory, problems, and the advantages for such instruments. An experiment testing impulse collision theory (ICT) underscores the similarities with sector mass spectrometers where this concept was first developed. Applications provide examples of more extensive fragmentation, side chain cleavages, and charge-remote fragmentation, also characteristic of high energy sector mass spectrometers. Moreover, the so-called curved-field reflectron has enabled the design of instruments that are simpler, collect and focus all of the ions, and may provide the future technology for the clinic, for tissue imaging, and the characterization of microorganisms.
Collapse
Affiliation(s)
- Robert J Cotter
- Middle Atlantic Mass Spectrometry Laboratory, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| |
Collapse
|
3
|
Affiliation(s)
- Feng Xian
- Department
of Chemistry and
Biochemistry, Florida State University,
95 Chieftain Way, Tallahassee, Florida 32310-4390, United States
| | - Christopher L. Hendrickson
- Department
of Chemistry and
Biochemistry, Florida State University,
95 Chieftain Way, Tallahassee, Florida 32310-4390, United States
- Ion Cyclotron Resonance Program, National High Magnetic Field Laboratory, 1800
East Paul Dirac Drive, Tallahassee, Florida 32310-4005, United States
| | - Alan G. Marshall
- Department
of Chemistry and
Biochemistry, Florida State University,
95 Chieftain Way, Tallahassee, Florida 32310-4390, United States
- Ion Cyclotron Resonance Program, National High Magnetic Field Laboratory, 1800
East Paul Dirac Drive, Tallahassee, Florida 32310-4005, United States
| |
Collapse
|
4
|
Introduction to the Analysis and Risk of Nanomaterials in Environmental and Food Samples. COMPREHENSIVE ANALYTICAL CHEMISTRY 2012. [DOI: 10.1016/b978-0-444-56328-6.00001-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
5
|
Analysis and Fate of Organic Nanomaterials in Environmental Samples. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/b978-0-444-56328-6.00004-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
6
|
Dyachenko A, Goldflam M, Vilaseca M, Giralt E. Molecular recognition at protein surface in solution and gas phase: Five VEGF peptidic ligands show inverse affinity when studied by NMR and CID-MS. Biopolymers 2011; 94:689-700. [PMID: 20564038 DOI: 10.1002/bip.21462] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Protein-protein interactions comprise of collection of molecular recognition events that take place at protein surfaces. A better understanding of the mechanism behind these interactions would provide deeper insight into the nature of many diseases, caused by the malfunction of protein networks, and contribute to design of molecules for efficient modulating of these interactions. One major factor in molecular recognition mechanism is interaction of reacting species with aqueous media. Thus, comparative study of noncovalent complex behavior in solution and gas phase can provide valuable information about the role of the solvent. Here examined interactions of vascular endothelial growth factor (VEGF) protein with five peptidic ligands of the same molecular weight but with different affinities. Interactions of VEGF with ligands in solution were studied by ITC and NMR, and K(D)s were determined. Gas phase stability was addressed using CID-MS approach. The energy transfer model was taken and adapted for the calculation of binding energy. Peptides were ranked on the basis of both solution and gas phase affinity to VEGF. The results indicate that the ranking of peptides in terms of affinity in solution is reversed compared with the gas phase ranking. This observation opens up a vast field for the future study of the system, and the determination and characterization of factors, responsible for the change of stability of noncovalent protein-ligand complexes upon complete or partial removal of the solvent.
Collapse
Affiliation(s)
- Andrey Dyachenko
- Institute for Research in Biomedicine, Parc Científic de Barcelona, Barcelona, Spain
| | | | | | | |
Collapse
|
7
|
Farré M, Sanchís J, Barceló D. Analysis and assessment of the occurrence, the fate and the behavior of nanomaterials in the environment. Trends Analyt Chem 2011. [DOI: 10.1016/j.trac.2010.11.014] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
8
|
Petrovic M, Farré M, de Alda ML, Perez S, Postigo C, Köck M, Radjenovic J, Gros M, Barcelo D. Recent trends in the liquid chromatography–mass spectrometry analysis of organic contaminants in environmental samples. J Chromatogr A 2010; 1217:4004-17. [DOI: 10.1016/j.chroma.2010.02.059] [Citation(s) in RCA: 182] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 02/19/2010] [Accepted: 02/24/2010] [Indexed: 11/16/2022]
|
9
|
Cotter RJ, Swatkoski S, Becker L, Evans-Nguyen T. Time-of-flights and traps: from the Histone Code to Mars. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2010; 16:331-40. [PMID: 20530839 PMCID: PMC3401572 DOI: 10.1255/ejms.1082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Two very different analytical instruments are featured in this perspective paper on mass spectrometer design and development. The first instrument, based upon the curved-field reflectron developed in the Johns Hopkins Middle Atlantic Mass Spectrometry Laboratory, is a tandem time-of-flight mass spectrometer whose performance and practicality are illustrated by applications to a series of research projects addressing the acetylation, deacetylation and ADP-ribosylation of histone proteins. The chemical derivatization of lysine-rich, hyperacetylated histones as their deuteroacetylated analogs enables one to obtain an accurate quantitative assessment of the extent of acetylation at each site. Chemical acetylation of histone mixtures is also used to determine the lysine targets of sirtuins, an important class of histone deacetylases (HDACs), by replacing the deacetylated residues with biotin. Histone deacetylation by sirtuins requires the co-factor NAD+, as does the attachment of ADP-ribose. The second instrument, a low voltage and low power ion trap mass spectrometer known as the Mars Organic Mass Analyzer (MOMA), is a prototype for an instrument expected to be launched in 2018. Like the tandem mass spectrometer, it is also expected to have applicability to environmental and biological analyses and, ultimately, to clinical care.
Collapse
Affiliation(s)
- Robert J Cotter
- Middle Atlantic Mass Spectrometry Laboratory, Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | | | | | | |
Collapse
|
10
|
Berkout VD. Fragmentation of singly protonated peptides via interaction with metastable rare gas atoms. Anal Chem 2009; 81:725-31. [PMID: 19099409 DOI: 10.1021/ac802214e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The effects of metastable energy level and peptide sequence on the fragmentation patterns of singly charged peptide ions dissociated in collisions with metastable rare gas atoms were studied. Fragmentation spectra of singly charged peptide ions were shown to be more structure-informative and very different from those obtained in low-energy collision-induced dissociation. Unusual odd-electron radical a- and x-ions were observed. Several fragment ions corresponding to a side-chain loss were also observed, which allowed differentiation between leucine and isoleucine. The fragmentation mechanism depends on electronic energy transferred during interaction with metastable gas atoms and proceeds either via Penning ionization with formation of radical odd-electron doubly charged molecular cation or via high-energy excitation of internal degrees of freedom of the peptide cation.
Collapse
|
11
|
Ecotoxicity and analysis of nanomaterials in the aquatic environment. Anal Bioanal Chem 2008; 393:81-95. [DOI: 10.1007/s00216-008-2458-1] [Citation(s) in RCA: 357] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Revised: 08/05/2008] [Accepted: 10/02/2008] [Indexed: 11/25/2022]
|
12
|
Carado A, Passarelli MK, Kozole J, Wingate JE, Winograd N, Loboda AV. C60 secondary ion mass spectrometry with a hybrid-quadrupole orthogonal time-of-flight mass spectrometer. Anal Chem 2008; 80:7921-9. [PMID: 18844371 PMCID: PMC2646894 DOI: 10.1021/ac801712s] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A hybrid quadrupole orthogonal time-of-flight mass spectrometer optimized for matrix-assisted laser desorption ionization (MALDI) and electrospray ionization has been equipped with a C 60 cluster ion source. This configuration is shown to exhibit a number of characteristics that improve the performance of traditional time-of-flight secondary ion mass spectrometry (TOF-SIMS) experiments for the analysis of complex organic materials and, potentially, for chemical imaging. Specifically, the primary ion beam is operated as a continuous rather than a pulsed beam, resulting in up to 4 orders of magnitude greater ion fluence on the target. The secondary ions are extracted at very low voltage into 8 mTorr of N 2 gas introduced for collisional focusing and cooling purposes. This extraction configuration is shown to yield secondary ions that rapidly lose memory of the mechanism of their birth, yielding tandem mass spectra that are identical for SIMS and MALDI. With implementation of ion trapping, the extraction efficiency is shown to be equivalent to that found in traditional TOF-SIMS machines. Examples are given, for a variety of substrates that illustrate mass resolution of 12,000-15,600 with a mass range for inorganic compounds to m/ z 40,000. Preliminary chemical mapping experiments show that with added sensitivity, imaging in the MS/MS mode of operation is straightforward. In general, the combination of MALDI and SIMS is shown to add capabilities to each technique, providing a robust platform for TOF-SIMS experiments that already exists in a large number of laboratories.
Collapse
Affiliation(s)
- Anthony Carado
- Department of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802
| | - M. K. Passarelli
- Department of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802
| | - Joseph Kozole
- Department of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802
| | - J. E. Wingate
- Applied Biosystems/MDS Analytical Technologies, 71 Four Valley Drive, Concord, Ontario, CA
| | - Nicholas Winograd
- Department of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802
| | - A. V. Loboda
- Applied Biosystems/MDS Analytical Technologies, 71 Four Valley Drive, Concord, Ontario, CA
| |
Collapse
|