Collision-induced decomposition CID

The mass spectrum of compound 1 and of its 3-deutero derivative has been reported.33 Apart from a strong molecular ion, the principal feature is a peak at 91 m.u. due to a C6H5N radical ion. This ion or interconverting ions 139-141, which are obtained from many other compounds, heterocyclic and nonheterocyclic, have been studied by the technique of collision-induced decomposition (CID).210 A study of some triazolopyridine-7-methanols has shown that other pathways, notably loss of the CHN2 fragment, can become important.23... 

We may compare the shock reaction with the collision-induced decomposition (CID), because both reactions are characterized by the production of H2 and... 

The relaxation of ion kinetic energies to levels close to thermal values insures that endothermic processes are not promoted. However, before thermalization occurs, endothermic processes may take place. One of the endothermic processes that can potentially occur is collision induced decomposition (CID). The maximum energy ( int,max) that can be converted into internal degrees of freedom of the polyatomic ion (of mass oti) on collision can be calculated as ... 

By introducing a collision gas into Q2, collision-induced dissociation (CID) can be used to cause more ions to fragment (Figure 33.4). For example, with a pressure of argon in Q2, normal ions (mj ) collide with gas molecules and dissociate to give mj ions. CID increases the yield of fragments compared with natural formation of metastable ions without induced decomposition. 

Tandem quadrupole and magnetic-sector mass spectrometers as well as FT-ICR and ion trap instruments have been employed in MS/MS experiments involving precursor/product/neutral relationships. Fragmentation can be the result of a metastable decomposition or collision-induced dissociation (CID). The purpose of this type of instrumentation is to identify, qualitatively or quantitatively, specific compounds contained in complex mixtures. This method provides high sensitivity and high specificity. The instrumentation commonly applied in GC/MS is discussed under the MS/MS Instrumentation heading, which appears earlier in this chapter. 

Positive ion FAB mass spectra obtained with a double focusing mass spectrometer produced abundant molecular ions ([M] +) of carotenes and xanthophyUs with minimal fragmentation and no detectable thermal decomposition. Fragmentation of the precursor ion was enhanced by collision-induced dissociation (CID) using helium gas. ... 

In obtaining experimental information about the isomeric forms of ions, a variety of techniques have been used. These include ion cyclotron resonance (ICR),31 flow tube techniques, notably the selected ion flow tube (SIFT),32 and the selected ion flow drift tube (SIFDT)32 (and its simpler variant33), collision induced dissociation (CID),10,11 and the decomposition of metastable ions in mass spectrometers.13 All of these techniques are mentioned in the text of Section in whore they have provided data relevant to the present review. 

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