Spectrometry collisionally induced

Metastable ions yield valuable information on fragmentation in mass spectrometry, providing insight into molecular structure. In electron ionization, metastable ions appear naturally along with the much more abundant normal ions. Abundances of metastable ions can be enhanced by collisionally induced decomposition. 

Fast Atom Bombardment Combined with Tandem Mass Spectrometry for the Study of Collisionally Induced Remote Charge Site Decompositions... 

E. Yoon and R. A. Laine, Linkage position determination in a novel set of permethylated neutral trisaccharides by collisional-induced dissociation and tandem mass spectrometry. Biol. Mass Spectrom., 21 (1992) 479-485. 

Flamini, R. and Dalla Vedova, A. (2004) Fast determination of the total free resver-atrol content in wine by direct-exposure-probe, positive-ion-chemical-ionization and collisional-induced-dissociation mass spectrometry (DEP/PICI-MS/MS), Rapid Commun. Mass Spectrom. 18(17), 1925-1931. 

Figure 6.7. Product ion spectrum of direct infusion ESI generated [M-H]- species of piceatannol. The ESI conditions are the same reported in the caption of Fig. 6.6. (Reprinted from Rapid Communications in Mass Spectrometry 22, Stella et al., Collisionally induced fragmentation of [M-Hp species of resveratrol and piceatannol investigated by deuterium labeling and accurate mass measurements, p. 3870, Copyright 2008, with permission from John Wiley Sons, Ltd.)...

Burgers PC, Holmes JL, Mommers AA, Szulejko JE and Terlouw JK (1984) Collisionally induced dissociative ionization of the neutral products from unimolecular ion fragmentations. Organic Mass Spectrometry 19 442-447. 

The use of tandem mass spectrometry <88MI 711-08) to study the collision-induced dissociation of protonated heterocycles has invited further attention in the 1990s. Thus following collisional acti-... 

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). ... 

In atomic laser spectroscopy, the laser radiation, which is tuned to a strong dipole transition of the atoms under investigation, penetrates the volume of species evaporated from the sample. The presence of analyte atoms can be measmed by means of the specific interaction between atoms and laser photons, such as by absorption techniques (laser atomic absorption spectrometry, LAAS), by fluorescence detection (laser-induced fluorescence spectroscopy, LIFS), or by means of ionization products (electrons or ions) of the selectively excited analyte atoms after an appropriate ionization process (Figures lA and IB). Ionization can be achieved in different ways (1) by interaction with an additional photon of the exciting laser or of a second laser (resonance ionization spectroscopy, RIS, or resonance ionization mass spectrometry, RIMS, respectively, if combined with a mass detection system) (2) by an electric field applied to the atomization volume (field-ionization laser spectroscopy, FILS) or (3) by collisional ionization by surrounding atoms (laser-enhanced ionization spectroscopy, LEIS). 

In addition, new tandem mass spectrometry technologies were also among the important innovations. Apart from traditional collision-induced dissociation (CID) [89-91], a variety of activation methods (used to add energy to mass-selected ions) based on inelastic collisions and photon absorption have been widely utilized. They include IR multiphoton excitation [92,93], UV laser excitation [94—97], surface-induced dissociation (SID) [98-100], black body radiation (101, 102], thermal dissociation [103], and others. As the fragmentation of peptide/protein ions is a central topic in proteomics, there is strong interest in such novel ion dissociation methods as electron capture dissociation (ECD) [104, 105] and electron transfer dissociation [22]. These new methods can provide structural information that complements that obtained by traditional collisional activation. Also, very recently, ambient ion dissociation methods such as atmospheric pressure thermal dissociation [106] and low temperature plasma assisted ion dissociation [107] have been reported. 

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