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Deferm C, Van den Bossche A, Luyten J, Oosterhof H, Fransaer J, Binnemans K. Thermal stability of trihexyl(tetradecyl)phosphonium chloride. Phys Chem Chem Phys 2018; 20:2444-2456. [DOI: 10.1039/c7cp08556g] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The thermal stability of the ionic liquid Cyphos IL 101 was investigated under various experimental conditions for possible high-temperature applications.
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Affiliation(s)
- Clio Deferm
- KU Leuven
- Department of Chemistry
- B-3001 Heverlee
- Belgium
- Umicore
| | | | - Jan Luyten
- Umicore
- Group Research & Development
- Competence Area Recycling and Extraction Technologies
- B-2250 Olen
- Belgium
| | - Harald Oosterhof
- Umicore
- Group Research & Development
- Competence Area Recycling and Extraction Technologies
- B-2250 Olen
- Belgium
| | - Jan Fransaer
- KU Leuven
- Department of Materials Engineering
- B-3001 Heverlee
- Belgium
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Boyd R. From physical chemistry to mass spectrometry to government lab manager in half a century. MASS SPECTROMETRY REVIEWS 2016; 35:272-310. [PMID: 24911188 DOI: 10.1002/mas.21433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 03/26/2014] [Indexed: 06/03/2023]
Affiliation(s)
- Robert Boyd
- Researcher Emeritus, National Research Council of Canada, 40-1425 Lamey's Mill Road, Vancouver, British Columbia, Canada, V6H 3W2
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Subramaniam R, Östin A, Nygren Y, Juhlin L, Nilsson C, Åstot C. An isomer-specific high-energy collision-induced dissociation MS/MS database for forensic applications: a proof-of-concept on chemical warfare agent markers. JOURNAL OF MASS SPECTROMETRY : JMS 2011; 46:917-924. [PMID: 21915956 DOI: 10.1002/jms.1970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Spectra database search has become the most popular technique for the identification of unknown chemicals, minimizing the need for authentic reference chemicals. In the present study, an isomer-specific high-energy collision-induced dissociation (CID) MS/MS spectra database of 12 isomeric O-hexyl methylphosphonic acids (degradation markers of nerve agents) was created. Phosphonate anions were produced by the electrospray ionization of phosphonic acids or negative-ion chemical ionization of their fluorinated derivatives and were analysed in a hybrid magnetic-sector-time-of-flight tandem mass spectrometer. A centre-of-mass energy (E(com)) of 65 eV led to an optimal sequential carbon-carbon bond breakage, which was interpreted in terms of charge remote fragmentation. The proposed mechanism is discussed in comparison with the routinely used low-energy CID MS/MS. Even-mass (odd-electron) charge remote fragmentation ion series were diagnostic of the O-alkyl chain structure and can be used to interpret unknown spectra. Together with the odd-mass ion series, they formed highly reproducible, isomer-specific spectra that gave significantly higher database matches and probability factors (by 1.5 times) than did the EI MS spectra of the trimethylsilyl derivatives of the same isomers. In addition, ionization by negative-ion chemical ionization and electrospray ionization resulted in similar spectra, which further highlights the general potential of the high-energy CID MS/MS technique.
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Affiliation(s)
- Raja Subramaniam
- Swedish Defence Research Agency, FOI CBRN Defence and Security, SE-901 82, Umeå, Sweden
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Pu D, Cassady CJ. Negative ion dissociation of peptides containing hydroxyl side chains. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2008; 22:91-100. [PMID: 18059044 DOI: 10.1002/rcm.3337] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The dissociation of deprotonated peptides containing hydroxyl side chains was studied by electrospray ionization coupled with Fourier transform ion cyclotron resonance (ESI-FTICR) via sustained off-resonance irradiation collision induced dissociation (SORI-CID). Dissociation under post-source decay (PSD) conditions was performed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF). This work included hexapeptides with one residue of serine, threonine, or tyrosine and five inert alanine residues. During SORI-CID and PSD, dissociation of [M-H](-) yielded c- and y-ions. Side-chain losses of formaldehyde (HCHO) from serine-containing peptides, acetaldehyde (CH(3)CHO) from threonine-containing peptides, and 4-methylene-2,5-cycohexadienone (C(7)H(6)O) from tyrosine-containing peptides were generally observed in the negative ion PSD and SORI-CID spectra. Side-chain loss occurs much less from tyrosine-containing peptides than from serine- and threonine-containing peptides. This is probably due to the bulky side chain of tyrosine, resulting in steric hindrance and poor geometry for dissociation reactions. Additionally, a selective cleavage leading to the elimination of the C-terminal residue from [M-H](-) was observed from the peptides with serine and threonine at the C-terminus. This cleavage does not occur in the dissociation of peptides with an amide group at the C-terminus or peptides with neutral or basic residues at the C-terminus. It also does not occur with tyrosine at the C-terminus. Both the C-terminal carboxylic acid group and the hydroxyl side chain of the C-terminal residue must play important roles in the mechanism of C-terminal residue loss. A mechanism involving both the C-terminal carboxylic acid group and a hydroxyl side chain of serine and threonine is proposed.
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Affiliation(s)
- Dan Pu
- Department of Chemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
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Ji H, Morré J, Voinov VG, Deinzer ML, Barofsky DF. Charge-Remote Metastable Ion Decomposition of Free Fatty Acids under FAB MS: Evidence for Biradical Ion Structures. Anal Chem 2007; 79:2822-6. [PMID: 17335179 DOI: 10.1021/ac0610356] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Classical charge-remote fragmentation (CRF) of a series of long-chain saturated and monounsaturated fatty acid anions, a well-known phenomenon under collisional activation conditions, is observed for the first time during fast atom bombardment of the analyte-matrix mixture without collisional activation. The process is efficient enough to allow collision-induced dissociation and metastable ion decomposition MS/MS spectra of any charge-remote [M-H2-(CH2)n]- fragments as well as spectra of neutral losses to be recorded. The results obtained are in contradiction to the generally accepted theory that CRF results exclusively in terminally unsaturated carboxylate anions. The new results indicate that a multistep radical mechanism is involved in CRF ion formation. The first step of the process appears to be accompanied by hydrogen elimination that occurs randomly throughout the molecule. The primary fragment radical ions formed can decompose further with the formation of the next generation of CRF ions.
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Affiliation(s)
- Hong Ji
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA
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Griffiths WJ, Alvelius G, Liu S, Sjövall J. High-energy collision-induced dissociation of oxosteroids derivatised to Girard hydrazones. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2004; 10:63-88. [PMID: 15100480 DOI: 10.1255/ejms.625] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Neutral oxosteroids have been derivatised with Girard T and P hydrazine reagents to give the corresponding Girard hydrazone quaternary ammonium salts. Both Girard T (GT) and Girard P (GP) hydrazones of oxosteroids give very intense [M](+) ion signals in electrospray (ES) mass spectra and fragment within the ES interface and collision cell to give characteristic fragment ions. GT and GP derivatives give informative high-energy collision-induced dissociation spectra, from which the structure of the precursor oxosteroid can be determined. Both charge-remote and charge-mediated mechanisms are responsible for the formation of the fragment ions at high collision-energy.
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Affiliation(s)
- William J Griffiths
- Department of Pharmaceutical & Biological Chemistry, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, UK
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Chen R, Yu X, Li L. Characterization of poly(ethylene glycol) esters using low energy collision-induced dissociation in electrospray ionization mass spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2002; 13:888-897. [PMID: 12148812 DOI: 10.1016/s1044-0305(02)00396-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A method of characterizing polyglycol esters, an important class of industrial polymer, has been developed using electrospray ionization ion trap mass spectrometry (ESI ITMS). The fragmentation behavior of polyglycol esters is found to be different from that of polyglycols whose functional end groups are linked to the polymer chain via ether bonds (i.e., polyglycol ethers). The fragmentation pattern of an oligomer ion generated by low-energy collision-induced dissociation is strongly dependent on the type of cation used for ionization. It is shown that structural information on the polymer chain and end groups is best obtained by examining the fragment ion spectra of oligomers ionized by ammonium, alkali, and transition metal ions. The application of this method is demonstrated in the analysis of two surfactants based on fatty acid methyl ester ethoxylates.
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Affiliation(s)
- Rui Chen
- Department of Chemistry, University of Alberta, Edmonton, Canada
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Voinov VG, Van den Heuvel H, Claeys M. Resonant electron capture mass spectrometry of free fatty acids: examination of ion structures using deuterium-labeled fatty acids and collisional activation. JOURNAL OF MASS SPECTROMETRY : JMS 2002; 37:313-321. [PMID: 11921373 DOI: 10.1002/jms.285] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The structures of [M-H](-) ions generated from free fatty acids in resonant electron capture at energies of 1.2 and 7.2 eV were investigated using deuterium-labeled isotopomers and collision-induced dissociation. The [M-H](- small middle dot) ions occur in both a carboxylate anion and a carbanion form. While the formation of the carboxylate anion at 1.2 eV involves the loss of a carboxylic hydrogen, that at 7.2 eV involves the loss of a hydrogen from different positions in the aliphatic chain followed by a rearrangement of a carboxylic hydrogen on to the radical site in the chain. The [M-H-H(2)O](-) ion which is a minor ion in the resonant electron capture spectrum at 7.2 eV is shown to be a precursor for the charge-remote fragment ions corresponding to formal losses of a hydrogen and elements of alkanes. The [M-H-H(2)O](-) ion corresponding to the second major ion in the resonant electron capture spectrum at 7.2 eV is demonstrated to be consistent with a cyclopentanone anion structure. On the basis of new insights obtained in the present study and taking into account previous results, an updated proposal is presented for the mechanism of charge-remote fragmentation which operates in resonant electron capture of free fatty acids at 7.2 eV.
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Affiliation(s)
- Valery G Voinov
- University of Antwerp (UIA), Department of Pharmaceutical Sciences, Universiteitsplein 1, B-2610 Antwerp, Belgium
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Seto C, Grossert JS, Waddell DS, Curtis JM, Boyd RK. Effects of ionization mode on charge-site-remote and related fragmentation reactions of long-chain quaternary ammonium ions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2001; 12:571-579. [PMID: 11349955 DOI: 10.1016/s1044-0305(01)00220-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Comparison of collisionally activated fragment spectra of long-chain quaternary ammonium ions, formed by liquid-assisted secondary ion mass spectrometry (LSIMS) and electrospray ionization (ESI), shows the latter are dominated by radical cations while the former yield mainly even-electron charge-site-remote (CSR) fragments, similar to the report for different precursors by Cheng et al., J. Am. Soc. Mass Spectrom. 1998, 9, 840. Here, mixed-site fragmentation products (formal loss of a radical directly bonded to the nitrogen plus a radical derived from the long chain) are of comparable importance for both ionization techniques. These observations are difficult to understand if the CSR ions are formed by a concerted rearrangement-elimination reaction, since precollision internal energies of the ESI ions are much lower than those of the ions from LSIMS. Alternatively, if one discards the concerted mechanism for high-energy CA, and assumes that the even-electron fragments are predominantly formed via homolytic bond cleavage, the colder radical cations from ESI survive to the detector while the more energized counterparts from LSIMS preferentially lose a hydrogen atom to yield the CSR ions, as proposed by Wysocki and Ross (Int. J. Mass Spectrom. Ion Processes 1991, 104, 179). The present work also attempts to reconcile discrepancies involving critical energies and known structures for neutral fragments.
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Affiliation(s)
- C Seto
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
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Abstract
Studies on the applications, energetics, and mechanisms of charge-remote fragmentations are reviewed, with emphasis given to those articles published after 1992. Independent of the charge status, charge-remote fragmentations are analogous to gas-phase thermolysis. Under collisional activation and with a fixed charge, ions containing long-chain or poly-ring structures undergo charge-remote fragmentations, generating productions that are structurally informative. Interpretation of the production spectra enables one to elucidate molecular structures. Although charge-remote fragmentations have been successfully used in the structural determination of fatty acids, phospholipids, glycolipids, triacylglycerols, steroids, peptides, ceramides, and other systems, the energetics and mechanisms of these reactions are still debated because none of the existing mechanisms can explain all the experimental data.
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Affiliation(s)
- C Cheng
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
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Current literature in mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2000; 35:1148-1155. [PMID: 11006610 DOI: 10.1002/1096-9888(200009)35:9<1148::aid-jms982>3.0.co;2-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of mass spectrometry. Each bibliography is divided into 11 sections: 1 Books, Reviews & Symposia; 2 Instrumental Techniques & Methods; 3 Gas Phase Ion Chemistry; 4 Biology/Biochemistry: Amino Acids, Peptides & Proteins; Carbohydrates; Lipids; Nucleic Acids; 5 Pharmacology/Toxicology; 6 Natural Products; 7 Analysis of Organic Compounds; 8 Analysis of Inorganics/Organometallics; 9 Surface Analysis; 10 Environmental Analysis; 11 Elemental Analysis. Within each section, articles are listed in alphabetical order with respect to author (3 Weeks journals - Search completed at 28th. June 2000)
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