Collisional activation spectra of organic ions

McLafferty, Fred W.; Bente, P. F.; Kornfeld, Richard; Tsai, Susan; Howe, Ian

doi:10.1002/jms.1190300604

Cited by 20 publications

(15 citation statements)

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“…The transfer through the capillary took about 15 s; further 30 -60 s were necessary to allow for evaporation of the solvent and for further pumping to recover the ion source vacuum. To ensure smooth operation without discharges, the pressure inside the ion source housing was allowed to fall to at least 8 ϫ 10 Linked scans at constant B/E [44] were employed to acquire the first field-free region metastable ion or collision-induced dissociation (CID) [45,46] spectra of the selected precursor ions. For CID measurements helium was used as collision gas.…”

Section: Methodsmentioning

confidence: 99%

Liquid injection field desorption/ionization-mass spectrometry of ionic liquids

Gross

2007

J. Am. Soc. Mass Spectrom.

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Ten ionic liquids based on four types of organic cations, C ϩ (imidazolium, pyrrolidinium, pyridinium, and phosphonium), combined with various types of anions, AϪ, were analyzed by liquid injection field desorption/ionization-(LIFDI) mass spectrometry. For the purpose of LIFDI analysis the ionic liquids were dissolved in methanol, acetonitrile or tetrahydrofuran at concentrations of 0.01-0.1 l mL Ϫ1 . The measurements were performed on a double-focusing magnetic sector instrument. In all ionic liquid LIFDI spectra, the intact cation of the compound yielded the base peak accompanied by cluster ions of the general formula [C 2 A] ϩ and occasionally [C 3 A 2 ] ϩ . Tandem mass spectrometry and reconstructed ion chromatograms were employed to reveal the identity of the observed ions. Although limited to positive-ion mode, LIFDI also provided analytical information on the anions due to cluster ion formation. Depending on actual emitter condition and ionic liquid the limit of detection in survey scans was determined to 5-50 pg of ionic liquid. [1][2][3]. Consequently, there is a need for the development of methods for their analysis, be it for the sake of checking their purity, to verify their absence in products from processes where ILs are involved, or to monitor their distribution in the environment as a result of their long-term usage.Mass spectrometry (MS) offers various methods for the analysis of ionic analytes, with electrospray ionization (ESI) [4,5] and matrix-assisted laser desorption/ ionization (MALDI) [6,7] presently being the widest known techniques for that purpose. In addition, fast atom bombardment (FAB) [8,9] as well as field desorption (FD) [10 -12] Although being the longest established method for ionic analyte analysis, FD has been overlooked in this scenario of mass spectral techniques for IL analysis. Field desorption (FD) is known since the 1970s as a soft desorption/ionization method in mass spectrometry [10, 28 -30]. FD-MS has proven capabilities in analyzing nonionic low-to medium polarity compounds [12].FD employs strong electric fields in the order of 10 10 V m Ϫ1 (1 V Å Ϫ1 ) to effect the ionization of atoms and molecules [11,12,31]. The necessary field strength is normally achieved by setting whisker-bearing wiresso-called activated emitters [32][33][34]-to high electric potential of typically 10 -12 kV opposed to a counter electrode at ϳ2 mm distance. With the emitter at positive polarity, electron tunneling becomes possible from the analyte residing on the activated emitter's large surface into the emitter material. The analyte is thereby ionized very softly and the molecular ions generated are immediately extracted into the mass analyzer by action of the same electric field.Due to the advent of liquid injection field desorption/ionization (LIFDI) [35][36][37] the FD experiment can now be conducted easier, faster, and with more reproducibility than with the previous methodology of sample supply outside the ion source. If required, LIFDI offers fully inert sample transfer from se...

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Section: Methodsmentioning

confidence: 99%

Liquid injection field desorption/ionization-mass spectrometry of ionic liquids

Gross

2007

J. Am. Soc. Mass Spectrom.

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“…From these studies, it was concluded that the nature of the collision gas has little influence on the product fragment intensity ratios [16,17]. Though, in recent studies with other molecules, the nature of the collision gas was observed to influence the fragmentation [18][19][20].…”

Section: Introductionmentioning

confidence: 97%

“…In the late 1960s and early 1970s, McLafferty and co-workers performed in-depth studies of keV collisional activation fragmentation as a function of various parameters [16]. From these studies, it was concluded that the nature of the collision gas has little influence on the product fragment intensity ratios [16,17].…”

Section: Introductionmentioning

confidence: 99%

High-energy collisions of protonated enantiopure amino acids with a chiral target gas

Kulyk

Rebrov

Stockett

et al. 2015

International Journal of Mass Spectrometry

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“…C ollision-induced dissociation (CID) is the most commonly employed method for structural elucidation of various compounds ranging from small organic molecules to large biomolecules in mass spectrometry [1,2]. CID is usually accomplished by ion activation with electric fields and then ion energetic collisions with a neutral gas followed by chemical bond dissociation and ion fragmentation [3].…”

Section: Introductionmentioning

confidence: 99%

Theoretical Study of Dual-Direction Dipolar Excitation of Ions in Linear Ion Traps

Dang

Wang

et al. 2016

J. Am. Soc. Mass Spectrom.

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Abstract. The ion enhanced activation and collision-induced dissociation (CID) by simultaneous dipolar excitation of ions in the two radial directions of linear ion trap (LIT) have been recently developed and tested by experiment. In this work, its detailed properties were further studied by theoretical simulation. The effects of some experimental parameters such as the buffer gas pressure, the dipolar excitation signal phases, power amplitudes, and frequencies on the ion trajectory and energy were carefully investigated. The results show that the ion activation energy can be significantly increased by dual-direction excitation using two identical dipolar excitation signals because of the addition of an excitation dimension and the fact that the ion motion radius related to ion kinetic energy can be greater than the field radius. The effects of higher-order field components, such as dodecapole field on the performance of this method are also revealed. They mainly cause ion motion frequency shift as ion motion amplitude increases. Because of the frequency shift, there are different optimized excitation frequencies in different LITs. At the optimized frequency, ion average energy is improved significantly with relatively few ions lost. The results show that this method can be used in different kinds of LITs such as LIT with 4-fold symmetric stretch, linear quadrupole ion trap, and standard hyperbolic LIT, which can significantly increase the ion activation energy and CID efficiency, compared with the conventional method.

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Collisional activation spectra of organic ions

Cited by 20 publications

References 1 publication

Liquid injection field desorption/ionization-mass spectrometry of ionic liquids

Liquid injection field desorption/ionization-mass spectrometry of ionic liquids

High-energy collisions of protonated enantiopure amino acids with a chiral target gas

Theoretical Study of Dual-Direction Dipolar Excitation of Ions in Linear Ion Traps

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