ADVERTISEMENT RETURN TO ISSUEPREVObituaryNEXTRonald D. Grigsby (1936–2021)Michael A. Grayson*Michael A. GraysonWashington University in St. Louis (retired), 104 Amiot Court, St. Louis, Missouri 63146, United States*Email: [email protected]More by Michael A. GraysonCite this: J. Am. Soc. Mass Spectrom. 2022, 33, 4, 744–745Publication Date (Web):April 6, 2022Publication History Received19 January 2022Accepted26 January 2022Published online6 April 2022Published inissue 6 April 2022https://pubs.acs.org/doi/10.1021/jasms.2c00020https://doi.org/10.1021/jasms.2c00020obituaryACS PublicationsAmerican Chemical Society. Published 2022 by American Chemical Society. This publication is available under these Terms of Use. Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views300Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail PDF (4 MB) Get e-AlertscloseSUBJECTS:Distillation,Energy,Fossil fuels,Mass spectrometry,Probes Get e-Alerts

Fullerene-based compounds are being developed for an extensive range of biomedical applications, and may provide a completely new class of biologically useful reagents. In support of our continuing investigation and characterization of one such compound, e,e,e-fullerene(60)-63-tris malonic acid (1) we optimized the conditions for obtaining mass spectra. Both positive and negative ion mass spectra are obtained using electrospray ionization (ESI). However, the spectra are dramatically different in the different ionization modes. We studied the effect of solvent media, acid content as well as the concentration of the compound (1) on mass fragmentation pattern both in positive and negative mode. The best mass spectra were obtained when 1 was sprayed from a solution containing a weak organic acid added to aqueous methanol (1:1) in positive mode. We also analyzed the ion current as function of capillary voltage for selected ion. Fragment ions formed by the direct loss of carboxyl groups from the doubly-charged dimer occur for the loss of one, two and six carboxyl groups. Of these, the loss of one carboxyl is the most abundant. The dominant mechanism for the formation of singly-charged fragment ions arises from splitting of the doubly-charged dimers into singly-charged monomers with subsequent carboxyl losses.

Many compounds had molecular weights within the range of the mass spectrometer but were not volatile enough for introduction via the heated inlet system used for gas and liquid samples. The development of the solids probe to introduce such samples took place over several decades. In addition to the solids probe, a vacuum lock was also developed for the introduction of the tip of the solids probe to the ion source without having to `break' the source vacuum. Samples placed in the solids probe tip were heated, thus vaporizing sufficient sample to obtain a mass spectrum. Variations on controlling the probe tip temperature were developed for special situations.

The combination of gas chromatography with mass spectrometry originally required the use of molecular separators to interface the two instruments to transfer more of the analyte from the chromatographic eluate into the mass spectrometer ion source. The various molecular separators used for this purpose are described. With the development of chromatographic columns operating at significantly lower mass flow rates, such interface devices are no longer needed.

Mass spectrometry was created through investigation of the deflection of kanalstahlen in magnetic and electrostatic fields. Early work by Wien, Thomson, Dempster, and Aston led to extensive studies of isotopes and to better instruments. New ionization sources and double-focusing designs increased the range of substances that could analyze and the precision and sensitivity of the analyzers. Significant advances were made before World War II in Austria, Germany, Japan, and the United States. The World War II years brought the advent of commercial manufacture and business purchase of mass spectrometers as well as the development of new instrument designs, particularly by Nier. These opened the way to the growth, starting in the 1950s, of much more widespread commercial and research applications.

Organic Mass SpectrometryVolume 17, Issue 5 p. 246-246 Book Review Fred W. McLafferty. Interpretation of mass spectra, 3rd edition. University science books, California, 1980 (first two editions published by W. A. Benjamin). $13.00 Fred W. McLafferty, Fred W. McLaffertySearch for more papers by this authorMargaret N. Mruzek, Margaret N. Mruzek University College LondonSearch for more papers by this author Fred W. McLafferty, Fred W. McLaffertySearch for more papers by this authorMargaret N. Mruzek, Margaret N. Mruzek University College LondonSearch for more papers by this author First published: May 1982 https://doi.org/10.1002/oms.1210170511AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume17, Issue5May 1982Pages 246-246 RelatedInformation

John Bennett Fenn shared the 2002 Nobel Prize in Chemistry for his development of electrospray ionization (ESI). There are several excellent, in-depth biographical reviews of Fenn's scientific career Fenn (Angew. Chem., Int. Ed. 42, 3871-3894, 2003) and Fenn (Annu. Rev. Phys. Chem. 47, 1-41, 1996). The focus of this report is to trace the random walk nature of Fenn's career path and to highlight those critical events along that path that led him to the important work for which he was recognized, the development of ESI as a means of ionizing large molecules and interfacing the liquid chromatograph to the mass spectrometer. In addition, this report should hopefully convey something of the curious, generous, kind, and outgoing nature of the man.

Recent advances in the resolving power of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) enable the detailed characterization of linear homopolymers, and in particular provide invaluable data for the determination of their end-group functionalities. With the growing importance of macromolecular coupling reactions in building complex polymer architectures, the ability to accurately monitor end-group transformations is becoming increasingly important for synthetic polymer chemists. This tutorial demonstrates the application of MALDI-TOF MS in determining both end-group functionalities and their transformations for linear homopolymers. Examples of both polycaprolactone and polystyrene are examined, and the strengths and weaknesses of various approaches to data analysis are given.

The aim of this work is to establish a quantitative method to determine the ratio of [U-13C] labeled to unlabeled hexose monophosphates isolated from yeast extracts. This is accomplished by anion exchange chromatography and mobile phase desalting followed by electrospray (ESI) mass spectrometry. We test the method with the analysis of a sample of biological origin. Previously developed analytical techniques are not adequate to accomplish mass spectrometric analysis of these and other small monosaccharide systems because of interference from salt clusters. By lowering the ionic strength of the mobile phase and using a simplified injection system to the mass spectrometer, we were able to obtain data on the relative abundance of the hexose monophosphates.

The propensity of various insulins and their analogs to oligomerize was investigated by mass spectrometric methods including measurement of the relative abundances of oligomers in the gas phase and the kinetics of H/D amide exchange. The kinetics of deuterium uptake show a good fit when the exchanging amides are placed in three kinetic groups: fast, intermediate, and slow. r-Human insulin, of the insulins investigated, has fewer amides that exchange at intermediate rates and more that exchange at slow rates, in accord with its higher extent of association in solution. We adapted PLIMSTEX (protein ligand interactions by mass spectrometry, titration, and H/D exchange) to determine protein/ligand affinities in solution, to determine self-association equilibrium constants for proteins, and to apply them to various insulin analogs. We term this adaptation SIMSTEX (self-association interactions using mass spectrometry, self-titration and H/D exchange); it gives affinity constants that compare well with the literature results. The results from SIMSTEX show that some mutants (e. g., GlnB13) have an increased tendency to self-associate, possibly slowing down their action in vivo. Other mutants (e. g., lispro and AspB9) have lower propensities for self-association, thus providing potentially faster-acting analogs for use in controlling diabetes.

The propensity of various insulins and their analogs to oligomerize was investigated by mass spectrometric methods including measurement of the relative abundances of oligomers in the gas phase and the kinetics of H/D amide exchange. The kinetics of deuterium uptake show a good fit when the exchanging amides are placed in three kinetic groups: fast, intermediate, and slow. r-Human insulin, of the insulins investigated, has fewer amides that exchange at intermediate rates and more that exchange at slow rates, in accord with its higher extent of association in solution. We adapted PLIMSTEX (protein ligand interactions by mass spectrometry, titration, and H/D exchange) to determine protein/ligand affinities in solution, to determine self-association equilibrium constants for proteins, and to apply them to various insulin analogs. We term this adaptation SIMSTEX (self-association interactions using mass spectrometry, self-titration and H/D exchange); it gives affinity constants that compare well with the literature results. The results from SIMSTEX show that some mutants (e.g., GlnB13) have an increased tendency to self-associate, possibly slowing down their action in vivo. Other mutants (e.g., lispro and AspB9) have lower propensities for self-association, thus providing potentially faster-acting analogs for use in controlling diabetes. (J Am Soc Mass Spectrom 2006, 17, 1526 –1534) © 2006 American Society for Mass Spectrometry

Introduction Self-association is an important phenomenon in all biological processes. We wish to develop mass spectrometric methods combined with amide exchange and mathematical modeling to study self-association. We chose insulin, a protein with 51 residues, in two chains linked by two disulfide bonds [1], as a model because it exists as monomer, the supposed active form, only at low concentrations (< 0.1 uM). At higher concentration and in the presence of Zn ions, however, three dimers assemble further into a hexamer. Insulin has the size of a polypeptide but the structural features of a large protein; therefore, it is a good model for studying the self-association properties of proteins. Insulin is used for the treatment of type I diabetes, but the large size of the hexamer prevents its efficient absorption into the blood stream [2]. The problem of aggregates can be attenuated by using analogs of insulins that are stable in monomeric form [3]. One such analog, lispro insulin, in which positions P28 and K29 in human insulin are reversed, has a dimerization constant that is smaller by a factor of 300 compared to that of r-human insulin [4(a) and 4(b)] whereas the receptor binding is unaffected. This report describes a novel mass spectrometric method to study self-association properties of various insulins by using amide exchange and MS. We measure the number of amide H’s protected in the various oligomeric states by modeling the data with a modified version of the program developed for PLIMSTEX [6]

This work traces the evolution of mass spectral databases from their inception as reference standards for use in quantitative analy- sis to their more recent application for the identification of un- known compounds from their mass spectra. The creation and use of mass spectral databases is paralleled by the application of computers in the acquisition, reduction, and analysis of mass spectral data. With time the use of computers went through a transition from "add-on" systems, in which the computer re- placed an existing part of the data recording and processing sys- tem of the mass spectrometer, to integral systems, in which the computer is central to the operation of the instrument. With improved computer capabilities and more powerful software some of the tasks reserved for the analyst have been subsumed by the computer. A brief description of the mass spectrometer and the data it produces is provided for the benefit of those not familiar with the instrument.

ADVERTISEMENT RETURN TO ISSUEEditorialNEXTKlaus BiemannMichael A. GraysonMichael A. GraysonWashington University at St. Louis, USAMore by Michael A. GraysonCite this: J. Am. Soc. Spectrom. 2002, 13, 11, 1253Publication Date (Web):November 1, 2002Publication History Published online1 November 2002Published inissue 1 November 2002https://pubs.acs.org/doi/10.1016/S1044-0305(02)00454-3https://doi.org/10.1016/S1044-0305(02)00454-3editorialACS PublicationsCopyright © 2002 © American Society for Mass Spectrometry 2002. This publication is available under these Terms of Use. Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views17Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail PDF (121 KB) Get e-Alerts

The stable van der Waals molecule krypton inside C60 was isolated by HPLC from a mixture containing 99.9% empty C60. Four passes through a semipreparative PYE [2-(1-pyrenyl)ethylsilyl] column provided 140 μg of 90% pure Kr@C60, as confirmed by mass spectrometric analysis. The 13C NMR spectrum of Kr@C60 contains a single line shifted 0.39 ppm downfield from the C60 resonance. UV−visible spectroscopy shows that krypton incorporation causes a red shift of ca.. 45 cm-1 in the lowest singlet transition of C60. Three of the four allowed vibrational fundamentals are observed by infrared spectroscopy; each shows a small frequency increase in Kr@C60. A 12% acceleration in triplet state decay is measured at 77 K and attributed to an “endohedral heavy atom effect” induced by the krypton atom. It is concluded that coupling between the krypton atom and the π-electron system of the fullerene is small but significant.