Ion Sources and Mass Analyzers in Protein Characterization
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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. -
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 -
Comparison of the Characteristic Mass Fragmentations of Phenethylamines and Tryptamines by Electron Ionization Gas Chromatograph
applied sciences Article Comparison of the Characteristic Mass Fragmentations of Phenethylamines and Tryptamines by Electron Ionization Gas Chromatography Mass Spectrometry, Electrospray and Matrix-Assisted Laser Desorption Ionization Mass Spectrometry Bo-Hong Chen, Ju-Tsung Liu, Hung-Ming Chen, Wen-Xiong Chen and Cheng-Huang Lin * Department of Chemistry, National Taiwan Normal University, 88 Sec. 4 Tingchow Road, Taipei 11677, Taiwan; [email protected] (B.-H.C.); [email protected] (J.-T.L.); [email protected] (H.-M.C.); [email protected] (W.-X.C.) * Correspondence: [email protected]; Tel.: +886-2-7734-6170; Fax: +886-2-2932-4249 Received: 18 April 2018; Accepted: 19 June 2018; Published: 22 June 2018 Abstract: Characteristic mass fragmentation of 20 phenethylamine/tryptamine standards were investigated and compared by means of matrix assisted laser desorption/time-of-flight mass spectrometry (MALDI/TOFM), gas chromatography–electron ionization–mass spectrometry (GC-EI/MS) and liquid chromatography–electrospray ionization/mass spectrometry (LC-ESI/MS) + methods. As a result, three characteristic peaks ([M] and fragments from the Cβ-Cα bond breakage) were found to be unique and contained information useful in identifying 2C series compounds based on the GC-EI/MS method. We found that the protonated molecular ion ([M+H]+) and two types of fragments produced from the α-cleavage and β-cleavage processes were useful mass spectral information in the rapid screening and confirmation of phenethylamine and tryptamine derivatives when ESI/MS and MALDI/TOFMS methods were applied. This assay was successfully used to determine samples that contain illicit drugs. Keywords: phenethylamine; tryptamine; MALDI/TOFMS; GC-EI/MS; LC-ESI/MS 1. -
Mass Spectrometer Business Presentation Materials
Mass Spectrometer Business Presentation Materials Hiroto Itoi, Corporate Officer Deputy General Manager of the Analytical & Measuring Instruments Division Shimadzu Corporation Jul. 3, 2018 Contents I. Introduction • Expansion of Mass Spectrometry ………………………………………………………………… p.3 • History of Shimadzu's Growth in Mass Spectrometry …………………………………………… p.5 II. Overview of Mass Spectrometers • Operating Principle, Demand Trends, and Vendors ……………………………………………… p.9 • Mass Spectra ………………………………………………………………………………………… p.10 • Configuration of Mass Spectrometers …………………………………………………………… p.11 • Ionization …………………………………………………………………………………………… p.12 • Mass Separation …………………………………………………………………………………… p.14 III. Shimadzu's Mass Spectrometer Business • Product Type ………………………………………………………………………………………… p.17 • Application Software ………………………………………………………………………………… p.18 • Growth Strategy for Mass Spectrometer Business ……………………………………………… p.19 • Expand/Improve Product Lines …………………………………………………………………… p.20 • Measures to Expand Application Fields …………………………………………………………… p.24 • Measures to Automate Data Processing Using AI ……………………………………………… p.25 IV. Summary • Future Direction ……………………………………………………………………………………… p.26 July 2018 Mass Spectrometer Business Presentation Materials 2 I. Introduction Expansion of Mass Spectrometry (1) Why Mass Spectrometry? Mass spectrometry is able to analyze a wide variety of compounds with high accuracy and high efficiency (simultaneous multicomponent analysis). It offers superior characteristics that are especially beneficial in the following fields, -
Coupling Gas Chromatography to Mass Spectrometry
Coupling Gas Chromatography to Mass Spectrometry Introduction The suite of gas chromatographic detectors includes (roughly in order from most common to the least): the flame ionization detector (FID), thermal conductivity detector (TCD or hot wire detector), electron capture detector (ECD), photoionization detector (PID), flame photometric detector (FPD), thermionic detector, and a few more unusual or VERY expensive choices like the atomic emission detector (AED) and the ozone- or fluorine-induce chemiluminescence detectors. All of these except the AED produce an electrical signal that varies with the amount of analyte exiting the chromatographic column. The AED does that AND yields the emission spectrum of selected elements in the analytes as well. Another GC detector that is also very expensive but very powerful is a scaled down version of the mass spectrometer. When coupled to a GC the detection system itself is often referred to as the mass selective detector or more simply the mass detector. This powerful analytical technique belongs to the class of hyphenated analytical instrumentation (since each part had a different beginning and can exist independently) and is called gas chromatograhy/mass spectrometry (GC/MS). Placed at the end of a capillary column in a manner similar to the other GC detectors, the mass detector is more complicated than, for instance, the FID because of the mass spectrometer's complex requirements for the process of creation, separation, and detection of gas phase ions. A capillary column is required in the chromatograph because the entire MS process must be carried out at very low pressures (~10-5 torr) and in order to meet this requirement a vacuum is maintained via constant pumping using a vacuum pump. -
(ESI) Electrospray Ionization
Electrospray Ionization (ESI) • sample solution • voltage drop • solvent evaporates is injected between source, away as droplets directly into analyzer generates migrate across gap instrument ionized droplets “sheath gas” Electrospray Ionization (ESI) Injected solution usually includes ionizing agent H+ (from acid), Na+, K+ Large droplets from injected stream Resulting ions can be spontaneously eject singly or multiply smaller droplets (due to charged electrostatic repulsion) Electrospray Ionization (ESI) Multiply charged ions frequently observed. ESI M [M•H]+ + [M•2H]2+ + [M•3H]3+ + ... or [M•Na]+ + [M•2Na]2+ + [M•3Na]3+ + ... multiply lysozyme: charged big > 10 kDa protein (protonated) ions From this series of peaks, how do we determine mass of protein? Charge Ladders in Electrospray Ionization We know two things: 1. Any peak corresponds to [M•nH]n+; ion mass m =M+= M + n, charge z = n. 2. Peak to that peak’s left has one more proton attached, one more charge; ion mass m = M + n + 1, charge z = n + 1. Charge Ladders in Electrospray Ionization Set of simultaneous equations: (observed m/z #1) • z = M + z(H+) (observed m/z #2) • (z + 1) = M + z(H+) + 1 2 1 Charge Ladders in Electrospray Ionization Now performed by computer algorithm Set of simultaneous equations: that searches for ladders, outputs likely mass candidates. 1486 • z = M + z 1372.5 • (z + 1) = M + z + 1 Solution: z = 12 M = 17827.2 [M•13H]13+ 2 [M•12H]1 12+ actual MW lysozyme: 17825.2 If sample contains a mixture of counterions, can get messy. ESI-MS 22-mer single-stranded DNA (difficult to desalt) Atmospheric Pressure Chemical Ionization (APCI) •+ •+ Analogous to CI, but uses discharge to generate N2 /O2 , which then iiionizes evapora tdltllThthiited solvent molecules. -
(LC-MS/MS) Method for the Determination of NDMA in Ranitidine Drug Substance and Solid Dosage Drug Product
10/17/2019 Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) Method for the Determination of NDMA in Ranitidine Drug Substance and Solid Dosage Drug Product Background: Ranitidine is a prescription and over-the-counter drug used to treat acid reflux. The drug is a histamine-2 receptor antagonist (acid inhibitor or H2 blocker). Some of the common H2 receptor blockers include: Ranitidine (Zantac), Nizatidine (Axid), Famotidine (Pepcid, Pepcid AC) and Cimetidine (Tagamet, Tagamet HB). Ranitidine medicine was suspected of being contaminated with N-nitroso-di-methylamine (NDMA), a probable human carcinogen, following notification in June 2019. Accordingly, a liquid chromatography-high resolution mass spectrometry (LC-HRMS) method was developed and validated by the Agency to determine the level of NDMA in ranitidine drug products and drug substances. This method is a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of NDMA in ranitidine drug substance and drug product. This LC-MS method based on a QQQ platform may be used as an alternative or confirmatory method for the liquid chromatography high resolution mass spectrometry (LC-HRMS) method detailed in FY19-177- DPA-S. The QQQ platform is more widely available than the LC-HRMS platform previously shared by the agency. Conclusions: An LC-MS/MS method was developed and validated following ICH Q2 (R1) for the detection and quantitation of NDMA in Ranitidine drug substance and drug product. The limit of detection (LOD), limit of quantitation (LOQ) and range of the method are summarized below: NDMA LOD (ng/mL) 0.3 (ppm) 0.01 LOQ (ng/mL) 1.0 (ppm) 0.033 Range (ng/mL) 1.0 - 100 (ppm) 0.033 – 3.33 Page 1 of 7 10/17/2019 LC-MS/MS Method for the Determination of NDMA impurity in Ranitidine Drug Substance or Solid Dosage Drug Product Purpose This method is used to quantitate N-nitroso-di-methylamine (NDMA) impurity in ranitidine drug substance or solid dosage drug product. -
Laser-Induced Dissociation of Phosphorylated Peptides Using
09_Cotter 10/19/07 7:57 AM Page 133 Clinical Proteomics Copyright © 2006 Humana Press Inc. All rights of any nature whatsoever are reserved. ISSN 1542-6416/06/02:133–144/$30.00 (Online) Original Article Laser-Induced Dissociation of Phosphorylated Peptides Using Matrix Assisted Laser Desorption/Ionization Tandem Time-of-Flight Mass Spectrometry Dongxia Wang,1 Philip A. Cole,2 and Robert J. Cotter2,* 1Biotechnology Core Facility, National Center for Infectious Disease, Center for Disease Control and Prevention, Atlanta, GA; 2Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD site or concensus sequence is present in a given Abstract tryptic peptide. Here, we investigated the frag- Reversible phosphorylation is one of the mentation of phosphorylated peptides under most important posttranslational modifications laser-induced dissociation (LID) using a of cellular proteins. Mass spectrometry is a MALDI-time-of-flight mass spectrometer with a widely used technique in the characterization of curved-field reflectron. Our data demonstrated phosphorylated proteins and peptides. Similar that intact fragments bearing phosphorylated to nonmodified peptides, sequence information residues were produced from all tested peptides for phosphopeptides digested from proteins can that contain at least one and up to four be obtained by tandem mass analysis using phosphorylation sites at serine, threonine, or either electrospray ionization or matrix assisted tyrosine residues. In addition, the LID of laser desorption/ionization (MALDI) mass phosphopeptides derivatized by N-terminal spectrometry. However, the facile loss of neutral sulfonation yields simplified MS/MS spectra, phosphoric acid (H3PO4) or HPO3 from precur- suggesting the combination of these two types sor ions and fragment ions hampers the precise of spectra could provide an effective approach determination of phosphorylation site, particu- to the characterization of proteins modified by larly if more than one potential phosphorylation phosphorylation. -
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