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Gas Cluster Ion Beams for Secondary Ion Mass Spectrometry
AC11CH02_Winograd ARI 3 May 2018 15:10 Annual Review of Analytical Chemistry Gas Cluster Ion Beams for Secondary Ion Mass Spectrometry Nicholas Winograd Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, USA; email: [email protected] Annu. Rev. Anal. Chem. 2018. 11:29–48 Keywords First published as a Review in Advance on bioimaging, cluster ion beams, phospholipids, instrumentation, molecular February 28, 2018 depth profiling, molecular dynamics computer simulations The Annual Review of Analytical Chemistry is online at anchem.annualreviews.org Abstract https://doi.org/10.1146/annurev-anchem- Gas cluster ion beams (GCIBs) provide new opportunities for bioimaging 061516-045249 Annual Rev. Anal. Chem. 2018.11:29-48. Downloaded from www.annualreviews.org and molecular depth profiling with secondary ion mass spectrometry (SIMS). Access provided by Pennsylvania State University on 02/26/19. For personal use only. Copyright c 2018 by Annual Reviews. These beams, consisting of clusters containing thousands of particles, ini- All rights reserved tiate desorption of target molecules with high yield and minimal fragmen- tation. This review emphasizes the unique opportunities for implementing these sources, especially for bioimaging applications. Theoretical aspects of ANNUAL REVIEWS Further the cluster ion/solid interaction are developed to maximize conditions for Click here to view this article's online features: successful mass spectrometry. In addition, the history of how GCIBs have • Download figures as PPT slides become practical laboratory tools is reviewed. Special emphasis is placed on • Navigate linked references • Download citations the versatility of these sources, as size, kinetic energy, and chemical compo- • Explore related articles • Search keywords sition can be varied easily to maximize lateral resolution, hopefully to less than 1 micron, and to maximize ionization efficiency. -
Mass Spectrometer Detectors
Mass Spectrometer Detectors www.sge.com Ion Detectors for Virtually all Mass Spectrometry Applications Electron multipliers are used in a wide range of applications to Figure 2. Secondary Electron Emission detect and measure small signals of ions, electrons or photons. One of the main applications for an electron multiplier is for 6 the detection of ions in a mass spectrometer. ACTIVE FILM Multipliers manufactured by ETP ( a division of SGE Group 5 of Companies) are the result of 15 years experience in 4 supplying high performance electron multipliers for use in mass spectrometry applications. The performance of this 3 unique type of ion detector has seen it become widely used in almost all fields of mass spectrometry (including ICP-MS, 2 GC-MS, LC-MS, TOF and SIMS). 1 An electron multiplier is used to detect the presence of ion Secondary Electron Emissions signals emerging from the mass analyser of a mass 0 spectrometer. It is essentially the "eyes" of the instrument (see 0 100 200 300 400 500 Figure 1). The task of the electron multiplier is to detect Incident Electron Energy (eV) every ion of the selected mass passed by the mass filter. How The average number of secondary electrons emitted from the efficiently the electron multiplier carries out this task surface of an ETP electron multiplier plotted against the represents a potentially limiting factor on the overall system energy of the incident primary electron. sensitivity. Consequently the performance of the electron multiplier can have a major influence on the overall (often referred to as a channel electron multiplier or CEM). -
Fundamental Understanding of Chemical Processes in Extreme Ultraviolet Resist Materials
Lawrence Berkeley National Laboratory Recent Work Title Fundamental understanding of chemical processes in extreme ultraviolet resist materials. Permalink https://escholarship.org/uc/item/50h4g627 Journal The Journal of chemical physics, 149(15) ISSN 0021-9606 Authors Kostko, Oleg Xu, Bo Ahmed, Musahid et al. Publication Date 2018-10-01 DOI 10.1063/1.5046521 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Fundamental understanding of chemical processes in extreme ultraviolet resist materials Oleg Kostko,1 Bo Xu,1 Musahid Ahmed,1 Daniel S. Slaughter,1 D. Frank Ogletree,2 Kristina D. Closser,2 David G. Prendergast,2 Patrick Naulleau,3 Deirdre L. Olynick,2 Paul D. Ashby,2 Yi Liu,2 William D. Hinsberg,4 Gregory M. Wallraff5 1Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA 2Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA 3Center for X‐Ray Optics, Lawrence Berkeley National Laboratory, Berkeley, CA, USA 4Columbia Hill Technical Consulting, Fremont, CA, USA 5IBM, Almaden, CA, USA ABSTRACT New photoresists are needed to advance extreme ultraviolet (EUV) lithography. Tailored design of efficient photoresists is enabled by a fundamental understanding of EUV induced chemistry. Processes that occur in the resist film after absorption of an EUV photon are discussed and a novel approach to study these processes on a fundamental level is described. The processes of photoabsorption, electron emission, and molecular fragmentation were studied experimentally in the gas‐phase on analogues of the monomer units employed in chemically amplified EUV resists. To demonstrate the dependence of the EUV absorption cross‐section on selective light harvesting substituents, halogenated methylpenols were characterized employing the following techniques. -
Microchannel Plate Detectors
Reprinted from Nuclear Instruments and Methods, Vol. 162, 1979, pages 587 to 601 MICROCHANNEL PLATE DETECTORS JOSEPH LADISLAS WIZA 1. Introduction typical. Originally developed as an amplification element for A microchannel plate (MCP) is an array of 104-107 image intensification devices, MCPs have direct sensitivity miniature electron multipliers oriented parallel to one to charged particles and energetic photons which has another (fig. 1); typical channel diameters are in the range extended their usefulness to such diverse fields as X-ray1) 10-100 µm and have length to diameter ratios (α) between and E.U.V.2) astronomy, e-beam fusion studies3) and of 40 and 100. Channel axes are typically normal to, or biased course, nuclear science, where to date most applications at a small angle (~8°) to the MCP input surface. The have capitalized on the superior MCP time resolution channel matrix is usually fabricated from a lead glass, characteristics4-6). treated in such a way as to optimize the secondary emission The MCP is the result of a fortuitous convergence of characteristics of each channel and to render the channel technologies. The continuous dynode electron multiplier walls semiconducting so as to allow charge replenishment was suggested by Farnsworth7) in 1930. Actual from an external voltage source. Thus each channel can be implementation, however, was delayed until the 1960s considered to be a continuous dynode structure which acts when experimental work by Oschepkov et al.8) from the as its own dynode resistor chain. Parallel electrical contact USSR, Goodrich and Wiley9) at the Bendix Research to each channel is provided by the deposition of a metallic Laboratories in the USA, and Adams and Manley10-11) at coating, usually Nichrome or Inconel, on the front and rear the Mullard Research Laboratories in the U.K. -
Characterization of Morphological and Chemical Properties of Scandium Containing
Characterization of Morphological and Chemical Properties of Scandium Containing Cathode Materials A dissertation presented to the faculty of the College of Arts and Sciences of Ohio University In partial fulfillment of the requirements for the degree Doctor of Philosophy Michael V. Mroz May 2020 © 2020 Michael V. Mroz. All Rights Reserved. 2 This dissertation titled Characterization of Morphological and Chemical Properties of Scandium Containing Cathode Materials by MICHAEL V. MROZ has been approved for the Department of Physics and Astronomy and the College of Arts and Sciences by Martin E. Kordesch Professor of Physics and Astronomy Florenz Plassmann Dean, College of Arts and Sciences 3 ABSTRACT MROZ, MICHAEL V., Ph.D., May 2020, Physics and Astronomy Characterization of Morphological and Chemical Properties of Scandium Containing Cathode Materials Director of Dissertation: Martin E. Kordesch Understanding thermionic cathodes is crucial for the future development of communication technologies operating at the terahertz frequency. Model cathode systems were characterized using multiple experimental techniques. These included Low Energy Electron Microscopy, X-Ray Photoemission Spectroscopy, and Auger Electron Spectroscopy. This was done to determine the mechanisms by which tungsten, barium, scandium, and oxygen may combine in order to achieve high current densities via thermionic emission. Barium and scandium films are found to dewet from the tungsten surfaces studied, and not diffuse out from bulk sources. The dewetted droplets were found to contribute the most to thermal emission. Barium oxide and scandium oxide are also found to react desorb from the emitting surface at lower temperatures then the metals themselves. The function of scandium in scandate cathodes was determined to act as an inhibitor to oxide formation. -
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. -
Ion-To-Neutral Ratios and Thermal Proton Transfer in Matrix-Assisted Laser Desorption/Ionization
B American Society for Mass Spectrometry, 2015 J. Am. Soc. Mass Spectrom. (2015) 26:1242Y1251 DOI: 10.1007/s13361-015-1112-3 RESEARCH ARTICLE Ion-to-Neutral Ratios and Thermal Proton Transfer in Matrix-Assisted Laser Desorption/Ionization I-Chung Lu,1 Kuan Yu Chu,1,2 Chih-Yuan Lin,1 Shang-Yun Wu,1 Yuri A. Dyakov,1 Jien-Lian Chen,1 Angus Gray-Weale,3 Yuan-Tseh Lee,1,2 Chi-Kung Ni1,4 1Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan 2Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan 3School of Chemistry, University of Melbourne, Melbourne, VIC 3010, Australia 4Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan Abstract. The ion-to-neutral ratios of four commonly used solid matrices, α-cyano-4- hydroxycinnamic acid (CHCA), 2,5-dihydroxybenzoic acid (2,5-DHB), sinapinic acid (SA), and ferulic acid (FA) in matrix-assisted laser desorption/ionization (MALDI) at 355 nm are reported. Ions are measured using a time-of-flight mass spectrometer combined with a time-sliced ion imaging detector. Neutrals are measured using a rotatable quadrupole mass spectrometer. The ion-to-neutral ratios of CHCA are three orders of magnitude larger than those of the other matrices at the same laser fluence. The ion-to-neutral ratios predicted using the thermal proton transfer model are similar to the experimental measurements, indicating that thermal proton transfer reactions play a major role in generating ions in ultraviolet-MALDI. Keywords: MALDI, Ionization mechanism, Thermal proton transfer, Ion-to-neutral ratio Received: 25 August 2014/Revised: 15 February 2015/Accepted: 16 February 2015/Published Online: 8 April 2015 Introduction in solid state UV-MALDI. -
Itwg Guideline Thermal Ionisation Mass Spectrometry (Tims) Executive Summary
NUCLEAR FORENSICS INTERNATIONAL TECHNICAL WORKING GROUP ITWG GUIDELINE THERMAL IONISATION MASS SPECTROMETRY (TIMS) EXECUTIVE SUMMARY Thermal Ionisation Mass Spectrometry (TIMS) is used for isotopic composition measurement of elements having relatively low ionisation potentials (e.g. Sr, Pb, actinides and rare earth elements). Also the concentration of an element can be determined by TIMS using the isotope dilution technique by adding to the sample a known amount of a “spike” [1]. TIMS is a single element analysis technique, thus it is recommended to separate all other elements from the sample before the measurement as they may cause mass interferences or affect the ionisation behaviour of the element of interest [2]. This document was designed and printed at Lawrence Livermore National Laboratory in 2017 with the permission of the Nuclear Forensics International Technical Working Group (ITWG). ITWG Guidelines are intended as consensus-driven best-practices documents. These documents are general rather than prescriptive, and they are not intended to replace any specific laboratory operating procedures. 1. INTRODUCTION The filament configuration in the ion source can be either single, double, or triple filament. In the single In TIMS, a liquid sample (typically in the diluted nitric acid filament configuration, the same filament serves both media) is deposited on a metal ribbon (called a filament for evaporation and ionisation. In the double and triple made of rhenium, tantalum, or tungsten) and dried. filament configurations, the evaporation of the sample The filament is then heated in the vacuum of the mass and the ionisation take place in separate filaments (Fig. spectrometer, causing atoms in the sample to evaporate 2). -
Methods of Ion Generation
Chem. Rev. 2001, 101, 361−375 361 Methods of Ion Generation Marvin L. Vestal PE Biosystems, Framingham, Massachusetts 01701 Received May 24, 2000 Contents I. Introduction 361 II. Atomic Ions 362 A. Thermal Ionization 362 B. Spark Source 362 C. Plasma Sources 362 D. Glow Discharge 362 E. Inductively Coupled Plasma (ICP) 363 III. Molecular Ions from Volatile Samples. 364 A. Electron Ionization (EI) 364 B. Chemical Ionization (CI) 365 C. Photoionization (PI) 367 D. Field Ionization (FI) 367 IV. Molecular Ions from Nonvolatile Samples 367 Marvin L. Vestal received his B.S. and M.S. degrees, 1958 and 1960, A. Spray Techniques 367 respectively, in Engineering Sciences from Purdue Univesity, Layfayette, IN. In 1975 he received his Ph.D. degree in Chemical Physics from the B. Electrospray 367 University of Utah, Salt Lake City. From 1958 to 1960 he was a Scientist C. Desorption from Surfaces 369 at Johnston Laboratories, Inc., in Layfayette, IN. From 1960 to 1967 he D. High-Energy Particle Impact 369 became Senior Scientist at Johnston Laboratories, Inc., in Baltimore, MD. E. Low-Energy Particle Impact 370 From 1960 to 1962 he was a Graduate Student in the Department of Physics at John Hopkins University. From 1967 to 1970 he was Vice F. Low-Energy Impact with Liquid Surfaces 371 President at Scientific Research Instruments, Corp. in Baltimore, MD. From G. Flow FAB 371 1970 to 1975 he was a Graduate Student and Research Instructor at the H. Laser Ionization−MALDI 371 University of Utah, Salt Lake City. From 1976 to 1981 he became I. -
Devices for Mass Spectrometry on a Chip
DEVICES FOR MASS SPECTROMETRY ON A CHIP Title: Professor Name: Richard R.A.Syms Affiliation/Address: EEE Dept., Imperial College London Phone: +44-207-594-6203 E-mail: [email protected] Devices for mass spectrometry on a chip Synonyms Mass spectrometer, mass analyser Definition A mass spectrometer is a vacuum analytical instrument that uses electric or magnetic fields or a mixture of the two to separate ions based on the ratio of their mass m to their charge q. A distinction is made between mass spectrometers, which produce a serially scanned output, and mass spectrographs, which produce a parallel (and sometimes graphical) output. The mass-to charge ratio is often written as m/z, where q = ze, e = 1.6 x 10-19 C is the electronic charge and z is the charge number. The ions are created from analyte molecules by processes that give rise to a characteristic pattern of fragments, in addition to the molecular ion itself, allowing a mass spectrometer to be used for chemical identification, compositional quantification and structural analysis. Performance is characterized in terms of the mass range (defined by the maximum mass mmax that can be measured), the mass resolution (defined as m/∆m, where ∆m is the uncertainty in the mass being measured) and the PAGE 1/25 DEVICES FOR MASS SPECTROMETRY ON A CHIP sensitivity. Applications include analytical chemistry, process and pollution monitoring, forensic science, the detection of drugs, chemical and biochemical weapons, and space exploration. In some cases, high performance is essential, while in others, low cost, small size, and portability are more desirable. -
How the Saha Ionization Equation Was Discovered
How the Saha Ionization Equation Was Discovered Arnab Rai Choudhuri Department of Physics, Indian Institute of Science, Bangalore – 560012 Introduction Most youngsters aspiring for a career in physics research would be learning the basic research tools under the guidance of a supervisor at the age of 26. It was at this tender age of 26 that Meghnad Saha, who was working at Calcutta University far away from the world’s major centres of physics research and who never had a formal training from any research supervisor, formulated the celebrated Saha ionization equation and revolutionized astrophysics by applying it to solve some long-standing astrophysical problems. The Saha ionization equation is a standard topic in statistical mechanics and is covered in many well-known textbooks of thermodynamics and statistical mechanics [1–3]. Professional physicists are expected to be familiar with it and to know how it can be derived from the fundamental principles of statistical mechanics. But most professional physicists probably would not know the exact nature of Saha’s contributions in the field. Was he the first person who derived and arrived at this equation? It may come as a surprise to many to know that Saha did not derive the equation named after him! He was not even the first person to write down this equation! The equation now called the Saha ionization equation appeared in at least two papers (by J. Eggert [4] and by F.A. Lindemann [5]) published before the first paper by Saha on this subject. The story of how the theory of thermal ionization came into being is full of many dramatic twists and turns.