Collision induced dissociation spectrum

This is the highest molecular weight compound for which infrared multiphoton dissociation has been observed in our laboratories to date. A similar pathway was indicated by the collision-induced dissociation spectrum of this ion. Limited CID experiments were performed on some of the other laser-desorbed ions discussed here and in general the CID and PD pathways were the same. 

Figure 26 Collision-induced dissociation spectrum of the m/z 256 Pb(CH30)(H 0)+ peak from Fig. 9.24.

M+H)+ of a derivative of the linear pentadecapeptide and antibiotic Val-gramicidicin A, a transmembrane protein this derivative has structure formyl-NH-V-G-A-L-A-V-V-V-W-L-W-L-W-L-W-ethanolamine. The CID (collision-induced dissociation) spectrum is very similar to a MALDI/TOF spectrum. Figure 11.10 shows the PSD of ACTH, the adenocorticotropic hormone. 

Figure 2. Collision-induced dissociation spectrum of ScFe (benzene) at 50 eV collision energy.

Collision-induced dissociation mass spectrum of tire proton-bound dimer of isopropanol [(CH2)2CHOH]2H. The mJz 121 ions were first isolated in the trap, followed by resonant excitation of their trajectories to produce CID. Fragment ions include water loss mJz 103), loss of isopropanol mJz 61) and loss of 42 anui mJz 79). (b) Ion-molecule reactions in an ion trap. In this example the mJz 103 ion was first isolated and then resonantly excited in the trap. Endothennic reaction with water inside the trap produces the proton-bound cluster at mJz 121, while CID produces the fragment with mJz 61. 

Time-of-flight mass spectrometers have been used as detectors in a wider variety of experiments tlian any other mass spectrometer. This is especially true of spectroscopic applications, many of which are discussed in this encyclopedia. Unlike the other instruments described in this chapter, the TOP mass spectrometer is usually used for one purpose, to acquire the mass spectrum of a compound. They caimot generally be used for the kinds of ion-molecule chemistry discussed in this chapter, or structural characterization experiments such as collision-induced dissociation. Plowever, they are easily used as detectors for spectroscopic applications such as multi-photoionization (for the spectroscopy of molecular excited states) [38], zero kinetic energy electron spectroscopy [39] (ZEKE, for the precise measurement of ionization energies) and comcidence measurements (such as photoelectron-photoion coincidence spectroscopy [40] for the measurement of ion fragmentation breakdown diagrams). 

Fig. 2.57. Identification of a flavonoid diglycoside from unhydrolized chokeberry sample, (a) Positive total ion chromatogram, (b) ion source collision-induced dissociation chromatogram for the ion m/z 303 (quercetin), (c) full scan MS spectrum of the peak at 14.1min, (d) full scan MS-MS spectrum of the [M+H] ion, (e) fragmentation spectrum (MS3) of the m/z 303.3 ion. Reprinted with permission from S. Hakkinen et al. [161].

Figure F4.5.1 Positive ion fast atom bombardment (FAB) with collision-induced dissociation (CID) tandem mass spectrum of pyropheophytin a isolated from spinach leaves. The FAB matrix was 3-nitrobenzyl alcohol.

The formation of methylsilver and dimethylargentate has been observed in the collision-induced dissociation MS3 spectrum of silver diacetate. Dimethylargentate is stable in the gas phase, and has been isolated for short periods (10 s) without significant decomposition.10... 

Spectrum of the ions produced by a collision-induced dissociation of the pseudomolecular ion of octanoylcamitine. This spectrum is obtained by selecting the 288 Th ion by means of the first analyser, fragmenting it through collision in the collision cell and analysing the fragments using the second spectrometer. 

Collision-induced dissociation FAB/MS/MS spectrum of an oligonucleotide containing a modified base. Reproduced (modified) from Iden C.R. and Rieger R.A., Biomed. Environ. Mass Spectrom., 18, 617, 1989, with permission. 

Collision-induced dissociation ESI/MS/MS spectrum of the LNF II oligosaccharide. Reproduced (modified) from Viseux N., de Hoffmann E. and Domon B., Anal. Chem., 69, 3193-3198,1997, with permission. 

Desorption chemical ionization (DCI) mass spectrum of natural cocoa butter and collision-induced dissociation DCI/MS/MS traces of deprotonated molecular ions of 887 Th (A), 859 Th (B) and 831 Th (C). Reproduced (modified) from Stroobant V., Rozenberg R., Bouabsa E.M., Deffense E. and de Hoffmann E., J. Am. Soc. Mass Spectrom., 6, 498-506, 1995, with permission. 

Approximately 80 pL of the remaining diluted HPLC fraction was subsequently subjected to mPC-CE-MS/MS. The doubly charged precursor ion at m/z 503.6 was subjected to collision induced dissociation and the resulting product ion spectrum (Figure 4) revealed a series of y and b ions. Interpretation of these ion series indicated a sequence of XSFKFDHX (where X is either 1 or L). The spectral data was also searched and interpreted using the Sequest database routine developed by Yates (17),... 

---