Collisionally induced dissociation spectra

Figure 4. Collisional induced dissociation spectra of the peptide of mass 582 from the reversed phase chromatogram of peak 2 in figure 3. CID conditions are described in Methods.

Lopez, L.L. Tiller, P.R, Senko, M.W. Schwartz, J.C. Automated Strategies for Obtaining Standardized Collisionally Induced Dissociation Spectra on a Benchtop Ion Trap Mass Spectrometer, Rapid Commun. Mass Spectrom. 13(8), 663-668 (1999). 

Earlier applications of tandem MS methods included the determination of the exact structure of China White (a-methylfentanyl) and the screening and confirmation of multiple drugs in biological fluids. The exact structure of a-methylfentanyl was pieced together through successive pairing of El complementary ions , whose sum of masses equals that of the molecular ion, and the determination of the structures of these paired ions by their collisionally induced dissociation spectra, i.e., MS/MS spectra. 

Figure 8 Curie-point pyrolysis MS-MS system pyrolysis products diffuses into the ion source where the ions are formed by electron-impact (El) ionization and analysed by a triple quadrupole mass analyser (Q1-Q3). Different modes of ion analysis (a) El spectrum of a pyrolysate (b) neutral loss spectrum (c) single ion spectrum and (d) collisionally induced dissociation spectrum of a parent ion...

Fig. 5. High energy collisionally induced dissociation mass spectrum for molecular ion MH+ m/z 1149 in fraction 9 (see Fig. la) corresponding to tryptic peptide P(133-144). Significant ions indicating the sequence are labeled.

Figure 2.3. Electrospray mass spectrum of sucrose obtained with a single quadrupole mass spectrometer (Thermo Electron) operated in the positive-ion mode. Fragmentation was achieved by in-source collisionally induced dissociation. The post-column addition of submillimolar LiCl to the analyte solution facilitated the formation of lithium adducts. (Reprinted from Ref. 28, with permission.)...

Figure 6 Schematic of collision-induced dissociation (CID) in the quadrupole ion trap (QIT) (MS2 experiment). In separate events, ions from the source are accumulated and trapped in the space at the center of the electrodes (a). Ions with a specified m/z value are retained in the trap and all others ejected (b). The specified ions are then collisionally fragmented by axial excitation between the two end caps (c). The resulting product ions are then sequentially ejected to generate the product ion spectrum (d). In an MS3 experiment, one of these product ions may be selectively retained in the trap, excited, and fragmented.

Several desorphon and spray ionization methods can be used to convert S5mthehc polymers into intact molecular or quasimolecular ions (vide supra), whose exact m/z ratio identifies the composition of the polymer. For structural informahon about the polymer, the dissociation behavior or ion-molecule reactions of the polymer ions must be studied. Such reactions, which rarely take place during the soft ionization processes necessary to generate intact gas phase ions from synthetic macromolecules, are most conveniently assessed by tandem mass spectrometry (MS/MS). With MS/MS, a specific precursor ion is mass-selected, so that its reactivity can be investigated without perturbation from the other ions formed upon ionization. The reaction products of this ion are then mass-analyzed and collected in the MS/MS spectrum. MS/MS studies on polymer ions have so far focused on their spontaneous ("metastable") or collision-induced fragmentation. The fragments arising in these reactions are displayed in metastable ion (MI) or collisionally activated dissociation (CAD) spectra, respectively. Customarily, MI spectra acquired with a TOF mass analyzer have been named "postsource decay (PSD)" spectra similarly, CAD is often referred to as CID (collision-induced dissociation). ... 

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