Methods of Ion Generation
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Characterization of a Glow Discharge Ion Source for the Mass Spectrometric Analysis of Organic Compounds
Characterization of a Glow Discharge Ion Source for the Mass Spectrometric Analysis of Organic Compounds D. Carazzato and M. J. Bertrand Regional Center for Mass Spectrometry, Department of Chemistry, University of Montreal, Montreal, Canada A glow discharge ion source has been constructed for the mass spectrometric analysis of organic compounds. Characterization of the source has been made by studying the effect of pressure and discharge current on ionic distributions by anodic ion sampling along the discharge axis. Ion and electron densities and electronic temperatures have been calculated by using the single Langmuir probe technique to correlate the extraction efficiency with measured ion distributions and gain some insight into the ionization of organic molecules. The spectra obtained for several classes of organic compounds show that formation of parent-molecular ions by proton transfer, resulting partly from the background water molecules, is a major low energy process while charge transfer, Penning ionization, and electron ionization are probably responsible for the fragmentation observed. The spectra result from the simultaneous occurrence of high and low energy reactions, and their structural information content is very high, yielding both molecular and extensive fragment ion information. The glow discharge ion source has proved to be essentially maintenance-free, easy to operate, stable, and can be used at reasonable mass resolution (up to 7000). The source also provides picogram range detection limits and has a linear response range of about six orders of magnitude, which makes it an interesting ion source for routine analysis. Preliminary work conducted with chromatographic interfaces indicates that its use can be easily extended to both gas and liquid chromatography. -
An Introduction to Isotopic Calculations John M
An Introduction to Isotopic Calculations John M. Hayes ([email protected]) Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA, 30 September 2004 Abstract. These notes provide an introduction to: termed isotope effects. As a result of such effects, the • Methods for the expression of isotopic abundances, natural abundances of the stable isotopes of practically • Isotopic mass balances, and all elements involved in low-temperature geochemical • Isotope effects and their consequences in open and (< 200°C) and biological processes are not precisely con- closed systems. stant. Taking carbon as an example, the range of interest is roughly 0.00998 ≤ 13F ≤ 0.01121. Within that range, Notation. Absolute abundances of isotopes are com- differences as small as 0.00001 can provide information monly reported in terms of atom percent. For example, about the source of the carbon and about processes in 13 13 12 13 atom percent C = [ C/( C + C)]100 (1) which the carbon has participated. A closely related term is the fractional abundance The delta notation. Because the interesting isotopic 13 13 fractional abundance of C ≡ F differences between natural samples usually occur at and 13F = 13C/(12C + 13C) (2) beyond the third significant figure of the isotope ratio, it has become conventional to express isotopic abundances These variables deserve attention because they provide using a differential notation. To provide a concrete the only basis for perfectly accurate mass balances. example, it is far easier to say – and to remember – that Isotope ratios are also measures of the absolute abun- the isotope ratios of samples A and B differ by one part dance of isotopes; they are usually arranged so that the per thousand than to say that sample A has 0.3663 %15N more abundant isotope appears in the denominator and sample B has 0.3659 %15N. -
Mass Spectrometry: Quadrupole Mass Filter
Advanced Lab, Jan. 2008 Mass Spectrometry: Quadrupole Mass Filter The mass spectrometer is essentially an instrument which can be used to measure the mass, or more correctly the mass/charge ratio, of ionized atoms or other electrically charged particles. Mass spectrometers are now used in physics, geology, chemistry, biology and medicine to determine compositions, to measure isotopic ratios, for detecting leaks in vacuum systems, and in homeland security. Mass Spectrometer Designs The first mass spectrographs were invented almost 100 years ago, by A.J. Dempster, F.W. Aston and others, and have therefore been in continuous development over a very long period. However the principle of using electric and magnetic fields to accelerate and establish the trajectories of ions inside the spectrometer according to their mass/charge ratio is common to all the different designs. The following description of Dempster’s original mass spectrograph is a simple illustration of these physical principles: The magnetic sector spectrograph PUMP F DD S S3 1 r S2 Fig. 1: Dempster’s Mass Spectrograph (1918). Atoms/molecules are first ionized by electrons emitted from the hot filament (F) and then accelerated towards the entrance slit (S1). The ions then follow a semicircular trajectory established by the Lorentz force in a uniform magnetic field. The radius of the trajectory, r, is defined by three slits (S1, S2, and S3). Ions with this selected trajectory are then detected by the detector D. How the magnetic sector mass spectrograph works: Equating the Lorentz force with the centripetal force gives: qvB = mv2/r (1) where q is the charge on the ion (usually +e), B the magnetic field, m is the mass of the ion and r the radius of the ion trajectory. -
Calibration Factors for Fast Flow Glow Discharge Mass Spectrometry (FF-GD-MS) in Continuous and Pulsed Mode
POSTER NOTE 30687 Calibration factors for Fast Flow Glow Discharge Mass Spectrometry (FF-GD-MS) in continuous and pulsed mode Authors: Torsten Lindemann, Joachim Hinrichs, Nicholas Lloyd, Thermo Fisher Scientific, Bremen, Germany Abstract The Thermo Scientific™ Element GD Plus™ GD-MS was used to measure a set of 13 iron based certified reference materials. Calibration factors for 29 elements were obtained in continuous and pulsed mode. In continuous mode operation, the calibration factors obtained confirm most of those factors previously used for semiquantitative analyses. However, significantly improved Introduction accuracy can be expected for Ti, V, Cr, and Zr with the Sector field glow discharge mass spectrometry is data obtained during this study. applied for the analysis of high purity bulk metals and alloys, semiconductors and ceramics, especially by the In pulsed mode operation, the calibration factors for many aerospace, electronics and photovoltaic industries. elements are similar to the ones in continuous mode. In detail though, some elements show lower calibration The Element GD Plus GD-MS features a fast flow glow factors. Therefore, a dedicated RSF table for pulsed mode discharge source that can be operated in continuous is recommended to support accurate routine operation for or pulsed mode. Continuous mode operation offers the semiquantitative analyses. advantage of high sputter rates to remove contaminated surface layers quickly. Also, the widely applied set of Most elements are analyzed within the accuracy range calibration factors (Standard RSF = general Relative of ±30 %, considered to be typical for semiquantitative Sensitivity Factors) is based on continuous mode operation. GD-MS analyses. For improved accuracy, the use of a dedicated set of calibration factors is advisable. -
Ion Trap Quantum Computer Selected Topics
Ion Trap Quantum Computer Selected Topics Ruben Andrist & Thomas Uehlinger 1 Outline Ion Traps Part I Deutsch-Josza Deutsch-Josza algorithm Problem Algorithm Implementation Part II Scalability Scalability of ion trap Problem Move ions quantum computers Microtraps Photons Charges Part III Roundup Roundup & Outlook Ruben Andrist Thomas Uehlinger 2 0:98.')4Part+8, 6: ,I39:2 .07.:09 $ " % H " !1 1# %1#% Quantum Algorithms H !1 1# %! 1#% 0"0.9743(.6:-(9 ( 5 ! ! 5 &1 ( 5 " "$1&!' 5 249(43,"6:-(9 # H !1 1# %1#%!4389,39( H !1 1# %! 1#% !,$,3.0/) ":,39:2,3,()8+8 ,+;08 9/0 7+,/9,38107 ,1907 ,8+3,(0 20,8:702039 3 W 0:98.)*# ,48.,*!74. # $4. 343/439*;99> W A0B803*C ):,3E*",3/"C*,2-7A/E0; > Implementation of the Deutsch-Josza Ion Traps algorithm using trapped ions Deutsch-Josza Problem ! show suitability of ion traps Algorithm Implementation ! relatively simple algorithm Scalability Problem ! using only one trapped ion Move ions Microtraps Photons Charges Paper: Nature 421, 48-50 (2 January 2003), doi:10.1038/nature01336; Institut für Experimentalphysik, Universität Innsbruck ! Roundup ! MIT Media Laboratory, Cambridge, Massachusetts Ruben Andrist Thomas Uehlinger 4 The two problems Ion Traps The Deutsch-Josza Problem: Deutsch-Josza ! Bob uses constant or balanced function Problem Alice has to determine which kind Algorithm ! Implementation Scalability Problem The Deutsch Problem: Move ions Bob uses a fair or forged coin Microtraps ! Photons ! Alice has to determine which kind Charges Roundup Ruben Andrist Thomas Uehlinger 5 Four -
The Use of Dc Glow Discharges As Undergraduate Educational Tools Stephanie A
The use of dc glow discharges as undergraduate educational tools Stephanie A. Wissel, Andrew Zwicker, Jerry Ross, and Sophia Gershman Citation: American Journal of Physics 81, 663 (2013); doi: 10.1119/1.4811435 View online: http://dx.doi.org/10.1119/1.4811435 View Table of Contents: http://scitation.aip.org/content/aapt/journal/ajp/81/9?ver=pdfcov Published by the American Association of Physics Teachers Articles you may be interested in Motivating Students to Do Homework Phys. Teach. 52, 295 (2014); 10.1119/1.4872413 Measuring the Effectiveness of Simulations in Preparing Students for the Laboratory Phys. Teach. 51, 113 (2013); 10.1119/1.4775536 New insights into student understanding of complete circuits and the conservation of current Am. J. Phys. 81, 134 (2013); 10.1119/1.4773293 Conductance quantization: A laboratory experiment in a senior-level nanoscale science and technology course Am. J. Phys. 81, 14 (2013); 10.1119/1.4765331 A low-cost spatial light modulator for use in undergraduate and graduate optics labs Am. J. Phys. 80, 211 (2012); 10.1119/1.3666834 This article is copyrighted as indicated in the article. Reuse of AAPT content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP: 198.35.1.48 On: Fri, 20 Jun 2014 16:13:40 The use of dc glow discharges as undergraduate educational tools Stephanie A. Wissela) and Andrew Zwickerb) Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 Jerry Ross Shawnee State University, Portsmouth, Ohio 45662 Sophia Gershman Advanced Research Innovation in Science Education (ARISE), Scotch Plains, New Jersey 07076 (Received 12 October 2012; accepted 4 June 2013) Plasmas have a beguiling way of getting students interested in physics. -
Type of Ionising Radiation Gamma Rays Versus Electro
MY9700883 A National Seminar on Application of Electron Accelerators, 4 August 1994 INTRODUCTION TO RADIATION CHEMISTRY OF POLYMER Khairul Zaman Hj. Mohd Dahlan Nuclear Energy Unit What is Radiation Chemistry? Radiation Chemistry is the study of the chemical effects of ionising radiation on matter. The ionising radiation flux in a radiation field may be expressed in terms of radiation intensity (i.e the roentgen). The roentgen is an exposure dose rather than absorbed dose. For radiation chemist, it is more important to know the absorbed dose i.e. the amount of energy deposited in the materials which is expressed in terms of Rad or Gray or in electron volts per gram. The radiation units and radiation power are shown in Table 1 and 2 respectively. Type of Ionising Radiation Gamma rays and electron beam are two commonly used ionising radiation in industrial process. Gamma rays, 1.17 and 1.33 MeV are emitted continuously from radioactive source such as Cobalt-60. The radioactive source is produced by bombarding Cobalt-59 with neutrons in a nuclear reactor or can be produced from burning fuel as fission products. Whereas, electrons are generated from an accelerator to produce a stream of electrons called electron beam. The energy of electrons depend on the type of machines and can vary from 200 keV to 10 MeV. Gamma Rays versus Electron Beam Gamma rays are electromagnetic radiation of very short wavelength about 0.01 A (0.001 nm) for a lMeV photon. It has a very high penetration power. Whereas, electrons are negatively charge particles which have limited penetration power. -
Theoretical Calculations for Electron Impact Ionization of Atoms and Molecules
Scholars' Mine Doctoral Dissertations Student Theses and Dissertations Fall 2017 Theoretical calculations for electron impact ionization of atoms and molecules Sadek Mohamed Fituri Amami Follow this and additional works at: https://scholarsmine.mst.edu/doctoral_dissertations Part of the Atomic, Molecular and Optical Physics Commons Department: Physics Recommended Citation Amami, Sadek Mohamed Fituri, "Theoretical calculations for electron impact ionization of atoms and molecules" (2017). Doctoral Dissertations. 2617. https://scholarsmine.mst.edu/doctoral_dissertations/2617 This thesis is brought to you by Scholars' Mine, a service of the Missouri S&T Library and Learning Resources. This work is protected by U. S. Copyright Law. Unauthorized use including reproduction for redistribution requires the permission of the copyright holder. For more information, please contact [email protected]. THEORETICAL CALCULATIONS FOR ELECTRON IMPACT IONIZATION OF ATOMS AND MOLECULES by SADEK MOHAMED FITURI AMAMI A DISSERTATION Presented to the Graduate Faculty of the MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY in PHYSICS 2017 Approved by Don H. Madison, Advisor Jerry L. Peacher Michael Schulz Daniel Fischer Gregory Gelles Copyright 2017 SADEK MOHAMED FITURI AMAMI All Rights Reserved iii PUBLICATION DISSERTATION OPTION This dissertation consists of the following ten articles which have been published as follows: Paper I: Pages 31-54 have been published by Phys Rev A.91.032707 (March 2015). Paper II: Pages 55-78 have been published by Phys Rev A.90.012704 (July 2014). Paper III: Pages 79-93 have been published by J. Phys. B: At. Mol. Opt. Phys. 49 185202 (September 2016). -
240 Ion Trap GC/MS External Ionization User's Guide
Agilent 240 Ion Trap GC/MS External Ionization User’s Guide Agilent Technologies Notices © Agilent Technologies, Inc. 2011 Warranty (June 1987) or DFAR 252.227-7015 (b)(2) (November 1995), as applicable in any No part of this manual may be reproduced The material contained in this docu- technical data. in any form or by any means (including ment is provided “as is,” and is sub- electronic storage and retrieval or transla- ject to being changed, without notice, tion into a foreign language) without prior Safety Notices agreement and written consent from in future editions. Further, to the max- Agilent Technologies, Inc. as governed by imum extent permitted by applicable United States and international copyright law, Agilent disclaims all warranties, CAUTION either express or implied, with regard laws. to this manual and any information A CAUTION notice denotes a Manual Part Number contained herein, including but not hazard. It calls attention to an oper- limited to the implied warranties of ating procedure, practice, or the G3931-90003 merchantability and fitness for a par- like that, if not correctly performed ticular purpose. Agilent shall not be or adhered to, could result in Edition liable for errors or for incidental or damage to the product or loss of First edition, May 2011 consequential damages in connection important data. Do not proceed with the furnishing, use, or perfor- beyond a CAUTION notice until the Printed in USA mance of this document or of any indicated conditions are fully Agilent Technologies, Inc. information contained herein. Should understood and met. 5301 Stevens Creek Boulevard Agilent and the user have a separate Santa Clara, CA 95051 USA written agreement with warranty terms covering the material in this document that conflict with these WARNING terms, the warranty terms in the sep- A WARNING notice denotes a arate agreement shall control. -
Contents • Introduction to Proteomics and Mass Spectrometry
Contents • Introduction to Proteomics and Mass spectrometry - What we need to know in our quest to explain life - Fundamental things you need to know about mass spectrometry • Interfaces and ion sources - Electrospray ionization (ESI) - conventional and nanospray - Heated nebulizer atmospheric pressure chemical ionization - Matrix assisted laser desorption • Types of MS analyzers - Magnetic sector - Quadrupole - Time-of-flight - Hybrid - Ion trap In the next step in our quest to explain what is life The human genome project has largely been completed and many other genomes are surrendering to the gene sequencers. However, all this knowledge does not give us the information that is needed to explain how living cells work. To do that, we need to study proteins. In 2002, mass spectrometry has developed to the point where it has the capacity to obtain the "exact" molecular weight of many macromolecules. At the present time, this includes proteins up to 150,000 Da. Proteins of higher molecular weights (up to 500,000 Da) can also be studied by mass spectrometry, but with less accuracy. The paradigm for sequencing of peptides and identification of proteins has changed – because of the availability of the human genome database, peptides can be identified merely by their masses or by partial sequence information, often in minutes, not hours. This new capacity is shifting the emphasis of biomedical research back to the functional aspects of cell biochemistry, the expression of particular sets of genes and their gene products, the proteins of the cell. These are the new goals of the biological scientist: o to know which proteins are expressed in each cell, preferably one cell at a time o to know how these proteins are modified, information that cannot necessarily be deduced from the nucleotide sequence of individual genes. -
Electron Ionization
Chapter 6 Chapter 6 Electron Ionization I. Introduction ......................................................................................................317 II. Ionization Process............................................................................................317 III. Strategy for Data Interpretation......................................................................321 1. Assumptions 2. The Ionization Process IV. Types of Fragmentation Pathways.................................................................328 1. Sigma-Bond Cleavage 2. Homolytic or Radical-Site-Driven Cleavage 3. Heterolytic or Charge-Site-Driven Cleavage 4. Rearrangements A. Hydrogen-Shift Rearrangements B. Hydride-Shift Rearrangements V. Representative Fragmentations (Spectra) of Classes of Compounds.......... 344 1. Hydrocarbons A. Saturated Hydrocarbons 1) Straight-Chain Hydrocarbons 2) Branched Hydrocarbons 3) Cyclic Hydrocarbons B. Unsaturated C. Aromatic 2. Alkyl Halides 3. Oxygen-Containing Compounds A. Aliphatic Alcohols B. Aliphatic Ethers C. Aromatic Alcohols D. Cyclic Ethers E. Ketones and Aldehydes F. Aliphatic Acids and Esters G. Aromatic Acids and Esters 4. Nitrogen-Containing Compounds A. Aliphatic Amines B. Aromatic Compounds Containing Atoms of Nitrogen C. Heterocyclic Nitrogen-Containing Compounds D. Nitro Compounds E. Concluding Remarks on the Mass Spectra of Nitrogen-Containing Compounds 5. Multiple Heteroatoms or Heteroatoms and a Double Bond 6. Trimethylsilyl Derivative 7. Determining the Location of Double Bonds VI. Library -
Modern Mass Spectrometry
Modern Mass Spectrometry MacMillan Group Meeting 2005 Sandra Lee Key References: E. Uggerud, S. Petrie, D. K. Bohme, F. Turecek, D. Schröder, H. Schwarz, D. Plattner, T. Wyttenbach, M. T. Bowers, P. B. Armentrout, S. A. Truger, T. Junker, G. Suizdak, Mark Brönstrup. Topics in Current Chemistry: Modern Mass Spectroscopy, pp. 1-302, 225. Springer-Verlag, Berlin, 2003. Current Topics in Organic Chemistry 2003, 15, 1503-1624 1 The Basics of Mass Spectroscopy ! Purpose Mass spectrometers use the difference in mass-to-charge ratio (m/z) of ionized atoms or molecules to separate them. Therefore, mass spectroscopy allows quantitation of atoms or molecules and provides structural information by the identification of distinctive fragmentation patterns. The general operation of a mass spectrometer is: "1. " create gas-phase ions "2. " separate the ions in space or time based on their mass-to-charge ratio "3. " measure the quantity of ions of each mass-to-charge ratio Ionization sources ! Instrumentation Chemical Ionisation (CI) Atmospheric Pressure CI!(APCI) Electron Impact!(EI) Electrospray Ionization!(ESI) SORTING DETECTION IONIZATION OF IONS OF IONS Fast Atom Bombardment (FAB) Field Desorption/Field Ionisation (FD/FI) Matrix Assisted Laser Desorption gaseous mass ion Ionisation!(MALDI) ion source analyzer transducer Thermospray Ionisation (TI) Analyzers quadrupoles vacuum signal Time-of-Flight (TOF) pump processor magnetic sectors 10-5– 10-8 torr Fourier transform and quadrupole ion traps inlet Detectors mass electron multiplier spectrum Faraday cup Ionization Sources: Classical Methods ! Electron Impact Ionization A beam of electrons passes through a gas-phase sample and collides with neutral analyte molcules (M) to produce a positively charged ion or a fragment ion.