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.

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.

Oxide, Hydroxide, and Doubly Charged Analyte Species in Inductively Coupled Plasma/Mass Spectrometry

1986 ◽  
Vol 40 (4) ◽  
pp. 434-445 ◽  
Author(s):  
M. A. Vaughan ◽  
G. Horlick
Keyword(s):  
Mass Spectrometry ◽  
Inductively Coupled Plasma ◽  
Inductively Coupled ◽  
Doubly Charged Ions ◽  
Oxide Hydroxide ◽  
Plasma Mass Spectrometry ◽  
Singly Charged ◽  
Doubly Charged ◽  
Oxide Ions ◽  
Charged Ions

In inductively coupled plasma/mass spectrometry analyte, M may be distributed among several species forms including doubly charged ions (M2+), singly charged ions (M+), mono-oxide ions (MO+), and hydroxide ions (MOH+). Detailed data are presented for Ba to illustrate the dependence of the ion count of these species and their ratios (M2+/M+, MO+/M+, and MOH+/M+) on nebulizer flow rate, plasma power, and sampling depth. Although these data are representative of most elements, many form oxides to a much greater degree than Ba; data are presented for Ti, W, and Ce to illustrate this fact. These various analyte species are important in that serious interelement interferences can occur because of spectral overlap. An extensive pair of tables indicating potential spectral interferences caused by element oxide, hydroxide, and doubly charged ions is presented.

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

Interpreting mass spectra of multiply charged ions

1989 ◽  
Vol 61 (15) ◽  
pp. 1702-1708 ◽  
Author(s):  
Matthias. Mann ◽  
Chin Kai. Meng ◽  
John B. Fenn
Keyword(s):  
Mass Spectra ◽  
Multiply Charged Ions ◽  
Multiply Charged ◽  
Charged Ions

A collisionally activated dissociation (CAD) and computational investigation of doubly and singly charged DMSO complexes of Cu2+

2005 ◽  
Vol 83 (11) ◽  
pp. 1921-1935 ◽  
Author(s):  
John A Stone ◽  
Timothy Su ◽  
Dragic Vukomanovic
Keyword(s):  
Electron Transfer ◽  
Collision Energy ◽  
Nbo Analysis ◽  
Computational Investigation ◽  
Doubly Charged Ions ◽  
Collisionally Activated Dissociation ◽  
The Difference ◽  
Singly Charged ◽  
Doubly Charged ◽  
Charged Ions

The singly and doubly charged Cu(II)–DMSO complexes formed by electrospray have been examined by CAD and computation. The CAD spectra were obtained as a function of collision energy. The doubly charged ions, [Cu(DMSO)n]2+, were observed only for n ≥ 2. For n = 3, dissociation leads mainly to [Cu(DMSO)2]+ + DMSO+, with only a trace of [Cu(DMSO)2]2+. Although [Cu(DMSO)]2+ was never detected, computation shows that the n = 1 complex exists in a potential well. Loss of DMSO+ is computed to be exothermic for n = 1–3, the exothermicity decreasing as n increases. The singly charged complexes in the ESI spectra were [CuX(DMSO)n]+ (X = Cl, Br, NO3, HSO4, n = 1 or 2). The CAD spectra showed competition between electron transfer from anion to metal followed by loss of X and loss of DMSO+. Experiment and computation show that for [CuX(DMSO)]+, loss of X is the preferred decomposition at low collision energy. NBO analysis shows that electron transfer to Cu from DMSO decreases in [Cu(DMSO)n]2+ as n increases, the bonding becoming more electrostatic and less covalent. In [CuX(DMSO)n]+, the negative charge on X is much less than unity with most of the difference appearing on the DMSO ligand(s).Key words: copper–DMSO complexes, electrospray, CAD, structures.

ChemInform Abstract: Multiply Charged Ions in the Mass Spectra of Trinuclear Carbonyl Metal Compounds and Their Derivatives

ChemInform ◽  
1988 ◽  
Vol 19 (32) ◽  
Author(s):  
P. BENZI ◽  
P. M. LAUSAROT ◽  
L. OPERTI ◽  
G. A. VAGLIO ◽  
M. VALLE ◽  
...  
Keyword(s):  
Mass Spectra ◽  
Multiply Charged Ions ◽  
Metal Compounds ◽  
Multiply Charged ◽  
Charged Ions

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.

scholarly journals Dynamics of Fragmentation Reactions From Peak Shapes in Multiparticle Coincidence Experiments

1991 ◽  
Vol 11 (3-4) ◽  
pp. 259-263 ◽  
Author(s):  
J. H. D. Eland
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Charge Separation ◽  
Mass Spectra ◽  
Doubly Charged Ions ◽  
Fragmentation Reactions ◽  
Doubly Charged ◽  
Charged Ions ◽  
Two Parameter ◽  
Experimental Survey

An experimental survey of peak shapes in two-parameter mass spectra from charge separation of doubly charged ions has been combined with Monte-Carlo simulations of peak shapes for different mechanisms. As a result, the major mechanisms, deferred charged separation, secondary dissociation and concerted explosion, can now be recognised. Finer details and a number of recurrent peculiar peak shapes remain unexplained.

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