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Ion Mobility (ion + mobility)

Distribution by Scientific Domains
Chemistry88%

Terms modified by Ion Mobility

  • ion mobility mass spectrometry
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  • ion mobility spectrometry
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    Selected Abstracts

    Ion Dynamics in Confined Spaces: Sodium Ion Mobility in Icosahedral Container Molecules,

    ANGEWANDTE CHEMIE, Issue 41 2010
    Maren Podewitz
    Gefangen und doch mobil: Ein zentrales PH2, -Ion (siehe Bild; magenta) ist in einem Behälter von zwölf tert -Butoxidanionen (rot und schwarz) in ikosaedrischer Anordnung verkapselt. Die 12 oder 13 Natriumgegenionen sind dynamisch über die 20 Ecken eines regulären Dodekaeders (blau) fehlgeordnet. Die Aktivierungsbarrieren für den Natriumaustausch sind bemerkenswert niedrig (10,30,kJ,mol,1) und liegen im Bereich schneller Lithiumionenleiter. [source]

    Peak width-mass correlation in CID MS/MS of isomeric oligosaccharides using traveling-wave ion mobility mass spectrometry

    JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 10 2009
    Tohru Yamagaki
    Abstract Isomeric oligosaccharides ,-cyclodextrin (,-CD), glucosyl-,CD (Glc1 -,CD) and maltosyl-,CD (Glc2 -,CD) were analyzed by traveling-wave ion mobility (twIM) mass spectrometry (MS). Their formation of multicharged multimers differed from each other. The ion mobility-mass spectrometry was useful in the self-assembling and complex formation analyses of CD isomers. The drift times of the isomers and their product ions with the same mass were almost the same in collision-induced dissociation (CID) MS/MS. In contrast, the ion mobility peak widths were sensitive to structural differences of the isomeric product ions. The twIM peak width (ms - µs) of the product ions [M , Glcn + H]+ (n = 0 , 6) of ,-CD correlated linearly with their masses (Da); the large and/or long chain product ions had wider peak widths, which were much wider than those from the general diffusion effect. This was a novel and useful ,trend line' to discriminate between the three isomers. Plots of [M , Glc2 , 6 + H]+ of Glc1 -,CD and [M , Glc3 , 6 + H]+ of Glc2 -,CD product ions' plots were on the same trend line as ,-CD. The plots of [M , Glc1 + H]+ of Glc1 -,CD and [M , Glc1, 2 + H]+ of Glc2 -,CD strayed from the ,-CD line; their peak widths were narrower than those of ,-CD. These results indicated that product ions from the chemical species of Glc1 -, CD and Glc2 -,CD retained their CD structure. Analyses of the IM peak widths enable us to elucidate the structures of the product ions. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    A multi-angular mass spectrometric view at cyclic nucleotide dependent protein kinases: In vivo characterization and structure/function relationships

    MASS SPECTROMETRY REVIEWS, Issue 4 2008
    Arjen Scholten
    Abstract Mass spectrometry has evolved in recent years to a well-accepted and increasingly important complementary technique in molecular and structural biology. Here we review the many contributions mass spectrometry based studies have made in recent years in our understanding of the important cyclic nucleotide activated protein kinase A (PKA) and protein kinase G (PKG). We both describe the characterization of kinase isozymes, substrate phosphorylation, binding partners and post-translational modifications by proteomics based methodologies as well as their structural and functional properties as revealed by native mass spectrometry, H/D exchange MS and ion mobility. Combining all these mass spectrometry based data with other biophysical and biochemical data has been of great help to unravel the intricate regulation of kinase function in the cell in all its magnificent complexity. © 2008 Wiley Periodicals, Inc. Mass Spec Rev 27: 331,353, 2008 [source]

    Particulate Matter Removal from Diesel Exhaust Gases by a Combination of Corona Discharge and Water or Oil Bath

    PLASMA PROCESSES AND POLYMERS, Issue 9 2006
    Yoshio Yoshioka
    Abstract Summary: As an efficient PM removal method from diesel exhausts, we developed a new method using a combination of a DC corona discharge and oil or water trays. The PM removal device generates DC corona discharges on oil or water filled in trays, thereby creating charges on the PMs, which can then be accelerated by an electric field towards the oil or water bath. The amount of PM absorbed in oil is determined by measuring light transmission. The discharge current on water is higher than that on oil. The difference of these discharge currents is considered to be due to the difference in ion mobility of the two liquids. An equation for PM removal characteristics is proposed. Using the equation, the PM removal by our device is estimated to be more than 85%. Experimental system for PM removal from diesel engine exhaust gas. [source]

    Desorption electrospray ionization mass spectrometric analysis of organophosphorus chemical warfare agents using ion mobility and tandem mass spectrometry

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 11 2010
    Paul A. D'Agostino
    Desorption electrospray ionization mass spectrometry (DESI-MS) has been applied to the direct analysis of sample media for target chemicals, including chemical warfare agents (CWA), without the need for additional sample handling. During the present study, solid-phase microextraction (SPME) fibers were used to sample the headspace above five organophosphorus CWA, O -isopropyl methylphosphonofluoridate (sarin, GB), O -pinacolyl methylphosphonofluoridate (soman, GD), O -ethyl N,N -dimethyl phosphoramidocyanidate (tabun, GA), O -cyclohexyl methylphosphonofluoridate (cyclohexyl sarin, GF) and O -ethyl S-2-diisopropylaminoethyl methyl phosphonothiolate (VX) spiked into glass headspace sampling vials. Following sampling, the SPME fibers were introduced directly into a modified ESI source, enabling rapid and safe DESI of the toxic compounds. A SYNAPT HDMSÔ instrument was used to acquire time-aligned parallel (TAP) fragmentation data, which provided both ion mobility and MSn (n,=,2 or 3) data useful for the confirmation of CWA. Unique ion mobility profiles were acquired for each compound and characteristic product ions of the ion mobility separated ions were produced in the TriwaveÔ transfer collision region. Up to six full scanning MSn spectra, containing the [M,+,H]+ ion and up to seven diagnostic product ions, were acquired for each CWA during SPME fiber analysis. A rapid screening approach, based on the developed methodology, was applied to several typical forensic media, including Dacron sampling swabs spiked with 5,µg of CWA. Background interference was minimal and the spiked CWA were readily identified within one minute on the basis of the acquired ion mobility and mass spectrometric data. Copyright © 2010 Crown in the right of Canada. Published by John Wiley & Sons, Ltd. [source]

    Electrospray ionization with ambient pressure ion mobility separation and mass analysis by orthogonal time-of-flight mass spectrometry

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 23 2001
    Wes E. Steiner
    Rapid screening and identification of drug and other mixtures are possible using a novel ambient pressure high-resolution ion mobility (APIMS) orthogonal reflector time-of-flight mass spectrometer (TOFMS). Departing ions from the APIMS drift tube traversed a pressure interface between the APIMS and TOFMS where they were subjected to numerous gas collisions that could produce selective fragmentation. By increasing the accelerating field in the pressure interface region, the ions generated using water-cooled electrospray ionization (ESI) underwent collision-induced dissociation (CID). Mixtures of ESI ions were separated by APIMS based on their respective size-to-charge (s/z) ratios while CID and analysis of mass-to-charge (m/z) ratios occurred in the pressure interface and TOFMS. Product ions that were formed in this pressure interface region could be readily assigned to precursor ions by matching the mobility drift times. This process was demonstrated by the examination of a mixture of amphetamines and the resulting fragmentation patterns of the mobility-separated precursor ion species [M,+,H]+. Copyright © 2001 John Wiley & Sons, Ltd. [source]

    Hexameric Palladium(II) Terpyridyl Metallomacrocycles: Assembly with 4,4,-Bipyridine and Characterization by TWIM Mass Spectrometry,

    ANGEWANDTE CHEMIE, Issue 37 2010
    Sujith Perera Dr.
    Groß und rund: Ein Makrocyclus mit 12 PdII -Terpyridyl-Einheiten wurde mithilfe von 4,4,-Bipyridyl-Liganden aufgebaut und durch NMR-Spektroskopie sowie TWIM-Massenspektrometrie charakterisiert (TWIM: traveling wave ion mobility). Der Makrocyclus (siehe Bild; C,grau, N,blau, Pd,orange) wurde auch durch Tandemmassenspektrometrie und Experimente mit stoßaktivierter Dissoziation (CAD) untersucht, und die resultierenden Fragmente wurden mit einem Flugzeitverfahren analysiert. [source]