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Collision induced dissociation characterization

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). [Pg.1354]

Cuyckens F, Shahat AA, Van den Heuvel H, Abdel-Shafeek KA, El-Messiry MM, Seif-El Nasr MM, Pieters L, Vlietinck AJ and Claeys M. 2003. The application of liquid chromatography-electrospray ionization mass spectrometry and collision-induced dissociation in the structural characterization of acylated flavonol O-glycosides from the seeds of Carrichtera annua. Eur J Mass Spectrom 9(4) 409-420. [Pg.82]

Ackloo, S. Z., Smith, R. W., Terlouw, J. K., and McCarry, B. E. (2000). Characterization of ginseng saponins using electrospray mass spectrometry and collision-induced dissociation experiments of metal-attachment ions. Analyst 125, 591-597. [Pg.80]

Ma, Y.L. et al.. Characterization of fiavone and fiavonol aglycones by collision-induced dissociation tandem mass spectrometry. Rapid Commun. Mass Spectrom., 11, 1357, 1997. [Pg.35]

FAB and LSIMS are matrix-mediated desorption techniques that use energetic particle bombardment to simultaneously ionize samples like carotenoids and transfer them to the gas phase for mass spectrometric analysis. Molecular ions and/or protonated molecules are usually abundant and fragmentation is minimal. Tandem mass spectrometry with collision-induced dissociation (CID) may be used to produce abundant structurally significant fragment ions from molecular ion precursors (formed using FAB or any suitable ionization technique) for additional characterization and identification of chlorophylls and their derivatives. Continuous-flow FAB/LSIMS may be interfaced to an HPLC system for high-throughput flow-injection analysis or on-line LC/MS. [Pg.959]

V. Kovacik, J. Hirsch, P. Kovac, W. Heerma, J. Thomas-Oates, and J. Haverkamp, Oligosaccharide characterization using collision-induced dissociation fast atom bombardment mass spectrometry Evidence for internal monosaccharide residue loss, J. Mass Spectrom., 30 (1995) 949-958. [Pg.136]

Maoka T, Fujiwara Y, Hashimoto K and Akimoto N, Characterization of epoxy carotenoids by fast atom bombardment collision-induced dissociation MS/MS. Lipids 39 179-183 (2004). [Pg.74]

Covey, T. R. Huang, E. C. Henion, J. D. 1991. Structural characterization of protein tryptic peptides via hquid chromatography/mass spectrometry and collision-induced dissociation of their doubly charged molecular ions. Anal. Chem., 63,1193-1200. [Pg.210]

For MS work, the electron impact (El) mode with automatic gain control (AGC) was used. The electron multiplier voltage for MS/MS was 1450 V, AGC target was 10,000 counts, and filament emission current was 60 pA with the axial modulation amplitude at 4.0 V. The ion trap was held at 200°C and the transfer line at 250°C. The manifold temperature was set at 60°C and the mass spectral scan time across 50-450 m/z was 1.0 s (using 3 microscans). Nonresonant, collision-induced dissociation (CID) was used for MS/MS. The associated parameters for this method were optimized for each individual compound (Table 7.3). The method was divided into ten acquisition time segments so that different ion preparation files could be used to optimize the conditions for the TMS derivatives of the chemically distinct internal standard, phenolic acids, and DIMBOA. Standard samples of both p-coumaric and ferulic acids consisted of trans and cis isomers so that four segments were required to characterize these two acids. The first time segment was a 9 min solvent delay used to protect the electron multiplier from the solvent peak. [Pg.171]

The third, often indispensable, component of an analytical strategy is the identiPcation and characterization of metallospecies, especially those for which standards are unavailable. This can be achieved by ES-MS or MALDI. Structural information can be acquired by collision-induced dissociation (CID) of an ion selected by a quadmpole (Q) mass Piter followed by a product ion scan using a Q or a time-of-Bight (TOF) mass analyzer. [Pg.514]

S.-I. Wu, A. F. R. Huhmer, Z. Hao, and B. L. Karger, On-line LCMS approach combining collision-induced dissociation (CID), electron transfer dissociation (ETD), and CID of an isolated charge-reduced species for the trace-level characterization of proteins with post-translational modifications, J. Proteome Res., 6 (2007) 4230 -244. [Pg.268]

Tandem mass spectrometry or MS/MS is frequently used for structural elucidation of phytochemicals to provide more detailed information about the structure and composition of a molecule. This involves two mass spectral steps and fragmentation of the compound occurs between the steps. The two steps may be separated in space or in time depending on whether two distinct separation elements are used (space) or two different separations occur in the same place over time. As described previously, an IT analyzer can be used to successively fragment a molecule to provide MS" spectra, an example of separation in time. A triple quadrupole mass spectrometer is a form of tandem mass spectrometry in space in which two quadrupoles serve as mass filters while a third, positioned in the middle, allows for collision-induced dissociation. Triple quadrupoles are common in phytochemical analysis, and have been used to characterize phenolic compounds in fruit juices (Abad-Garcia et ah, 2009) and procyanidins and alkaloids in cocoa (Ortega et ah, 2010), among others. [Pg.48]


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