scholarly journals Formation and fragmentation of doubly and triply charged ions in the negative ion spectra of neutral N-glycans from viral and other glycoproteins

2021 ◽  
Author(s):  
David J. Harvey ◽  
Weston B. Struwe ◽  
Anna-Janina Behrens ◽  
Snezana Vasiljevic ◽  
Max Crispin
Keyword(s):  
Detailed Comparison ◽  
Negative Ion ◽  
Doubly Charged Ions ◽  
Multiply Charged ◽  
Structural Details ◽  
Different Types ◽  
Doubly Charged ◽  
Ion Collision ◽  
Charged Ions

AbstractStructural determination of N-glycans by mass spectrometry is ideally performed by negative ion collision-induced dissociation because the spectra are dominated by cross-ring fragments leading to ions that reveal structural details not available by many other methods. Most glycans form [M – H]- or [M + adduct]- ions but larger ones (above approx. m/z 2000) typically form doubly charged ions. Differences have been reported between the fragmentation of singly and doubly charged ions but a detailed comparison does not appear to have been reported. In addition to [M + adduct]- ions (this paper uses phosphate as the adduct) other doubly, triply, and quadruply charged ions of composition [Mn + (H2PO4)n]n- have been observed in mixtures of N-glycans released from viral and other glycoproteins. This paper explores the formation and fragmentation of these different types of multiply charged ions with particular reference to the presence of diagnostic fragments in the CID spectra and comments on how these ions can be used to characterize these glycans. Graphical abstract

Differentiation of Ionised Benzimidazole from its Isomeric α-Distonic Ion by Collision-Induced Dissociation and Neutralisation—Reionisation Mass Spectrometry

2005 ◽  
Vol 11 (4) ◽  
pp. 381-387 ◽  
Author(s):  
Thanasis Karapanayiotis ◽  
Richard D. Bowen
Keyword(s):  
Mass Spectra ◽  
Radical Cations ◽  
Time Frame ◽  
Careful Consideration ◽  
Collision Induced Dissociation ◽  
Doubly Charged Ions ◽  
Doubly Charged ◽  
Ion Collision ◽  
Charged Ions ◽  
Distonic Ion

Ionised benzimidazole and its isomeric α-distonic ion (or ionised ylid) have been examined by recording their metastable ion, collision-induced dissociation and neutralisation–reionisation mass spectra. These tautomers may be distinguished by careful consideration of key features of the collision-induced dissociation spectra, with or without prior neutralisation and reionisation. Formation of doubly-charged ions by charge stripping occurs preferentially when the α-distonic ion is subjected to collision. This α-distonic ion survives neutralisation and reionisation, thus establishing that the corresponding ylid is stable on the microsecond time frame. The effects of benzannulation on the ease of differentiation of classical and distonic radical cations derived from biologically important heterocycles are considered.

Evidence from SIMS of Doubly-Charged Boron Contamination During Singly Charged-Ion Implantation

1990 ◽  
Vol 48 (2) ◽  
pp. 316-317
Author(s):  
D. S. Simons ◽  
P. H. Chi ◽  
D. B. Novotny
Keyword(s):  
Ion Implantation ◽  
Main Peak ◽  
Charged State ◽  
Exchange Reactions ◽  
Doubly Charged Ions ◽  
Multiply Charged ◽  
Residual Gas ◽  
Singly Charged ◽  
Doubly Charged ◽  
Charged Ions

When a dopant is introduced into a semiconductor material by ion implantation, it is sometimes desirable to accelerate and implant the ion in a multiply-charged state. This has the effect of increasing the energy and range of the ion without increasing the accelerating potential. Most modern ion implanters are of the pre-analysis type. In this design the ions are first accelerated through a modest extraction potential, e.g., 25 keV. This is followed by deflection for mass-to-charge selection in an analyzer magnet, after which the selected ions undergo final acceleration. Charge-exchange reactions between the doubly-charged ions and residual gas have been found to occur between the analyzing magnet and the final acceleration section. These reactions produce singly-charged ions that receive only half of the energy of the doubly-charged ions during final acceleration. For the case of B++ implantation the resulting implant profile shows a shallow-depth shoulder due to B+, the amplitude of which may be greater than 50% of the main peak.

Massenspektroskopische Festkörperuntersuchungen verbesserter Reproduzierbarkeit mit dem Gleichstrom-Abreißfunken im Vakuum zur lonenerzeugung

1963 ◽  
Vol 18 (8-9) ◽  
pp. 926-941 ◽  
Author(s):  
K. D. Schuy ◽  
H. Hintenberger
Keyword(s):  
Mass Spectra ◽  
Multiply Charged Ions ◽  
Doubly Charged Ions ◽  
Multiply Charged ◽  
Singly Charged ◽  
Main Component ◽  
Doubly Charged ◽  
Charged Ions ◽  
Spectrum Evaluation ◽  
Speed Of Analysis

Mass spectra obtained with the disjunctive d.c.-spark in vacuum show considerable improvement in accuracy and reproducibility over the conventional r.f.-spark of the DEMPSTER type. Higher ion currents increase the speed of analysis. A number of mass spectra were produced with a spectroscopic steel standard. The methods of visual and photometric spectrum evaluation are discussed in detail, using two quantities defined as “element sensitivity” and “normalized ionization sensitivity”. The former is a measure of how much more sensitive a given element can be photographically detected with the mass spectrograph than the main component of the sample (matrix element), while the latter indicates how much more sensitive multiply-charged ions of an element can be detected on the plate than singly-charged ions of the same element. Both element- and ionization sensitivities are reproducible to within approximately 20%. Furthermore, it is found, for most elements investigated, that the lines due to doubly-charged ions are more intense than those due to singly-charged ions and that the differences of element sensitivities of various elements decrease for ions of higher charge. The reproducibility of multiply-charged ions permits their use in the quantitative analysis of the sample.

ELECTRON TRANSFER TO MULTIPLY CHARGED IONS OF Ar, N2, N, AND O2

1967 ◽  
Vol 45 (4) ◽  
pp. 1451-1467 ◽  
Author(s):  
J. William McGowan ◽  
Larkin Kerwin
Keyword(s):  
Electron Transfer ◽  
Cross Sections ◽  
Large Scatter ◽  
Single Charge ◽  
Doubly Charged Ions ◽  
Multiply Charged ◽  
Double Electron ◽  
Doubly Charged ◽  
Charged Ions ◽  
Small Scatter

Cross sections for the transfer of one and of two electrons to fast doubly charged ions of Ar, O, N2, N, and to the triply charged ion of Ar are presented. The 20/02 reaction of Ar++ in Ar is resonant and smaller than that for Ar+ in Ar. The nonresonant, single-charge transfer process 20/11, even though it is exothermic, required that 12.5 ± 2.0 eV be transferred to the reaction from the kinetic energy of the projectile for the reaction to go. Consequently, the scatter of the fast Ar+ products is very large. Similarly, large scatter is observed for the double-electron transfer to Ar+++ as the ion traverses an argon target. Unlike the above, however, single- and double-electron transfer to O++ from O2 and to N2++ from N2, double transfer from Ar to Ar++, and single and triple transfer from Ar to Ar+++ show but small scatter.

Accurate determination of arsenic and selenium in plant food samples by using ICP-MS/MS

2016 ◽  
Vol 8 (32) ◽  
pp. 6150-6157 ◽  
Author(s):  
Xianqiao Hu ◽  
Zhaoyun Cao ◽  
Weihua Sun ◽  
Huan Yang ◽  
Ping Xu ◽  
...  
Keyword(s):  
Accurate Determination ◽  
Food Samples ◽  
Mass Shift ◽  
Plant Food ◽  
Doubly Charged Ions ◽  
Icp Ms ◽  
Doubly Charged ◽  
Charged Ions

In this paper, the influence of polyatomic and doubly charged ions on determination of As and Se was evaluated in four different modes. It was found that O2 mass-shift mode was an effective method to remove all interferences.

REACTIONS OF DOUBLY CHARGED IONS WITH VARIOUS NEUTRALS

1979 ◽  
Vol 40 (C7) ◽  
pp. C7-21-C7-22
Author(s):  
K. Peska ◽  
E. Alge ◽  
H. Villinger ◽  
H. Störi ◽  
W. Lindinger
Keyword(s):  
Doubly Charged Ions ◽  
Doubly Charged ◽  
Charged Ions

Triatomic molecules

2018 ◽  
Author(s):  
John H. D. Eland ◽  
Raimund Feifel
Keyword(s):  
Degrees Of Freedom ◽  
Normal Modes ◽  
Electronic States ◽  
Triatomic Molecules ◽  
Doubly Charged Ions ◽  
Spectral Bands ◽  
Valence Electrons ◽  
Doubly Charged ◽  
Charged Ions ◽  
Double Ionisation

Double ionisation of the triatomic molecules presented in this chapter shows an added degree of complexity. Besides potentially having many more electrons, they have three vibrational degrees of freedom (three normal modes) instead of the single one in a diatomic molecule. For asymmetric and bent triatomic molecules multiple modes can be excited, so the spectral bands may be congested in all forms of electronic spectra, including double ionisation. Double photoionisation spectra of H2O, H2S, HCN, CO2, N2O, OCS, CS2, BrCN, ICN, HgCl2, NO2, and SO2 are presented with analysis to identify the electronic states of the doubly charged ions. The order of the molecules in this chapter is set first by the number of valence electrons, then by the molecular weight.

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