fragment ion

fragment ion

A term defined in the context of mass spectrometry as the charged product of an ion dissociation. A fragment ion may be stable or dissociate further to form other charged fragment ions and neutral species of successively lower mass. Molecular ions formed in the initial ionisation dissociate to fragment ions because of excess internal energy remaining after ionisation.
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References in periodicals archive ?
The fragment ion of metronidazole is 128.0 m/z and 81.9 m/z, the fragment ion of tinidazole is 128.0 m/z and 92.8 m/z, the fragment ion of ornidazole is 127.9 m/z and 81.9 m/z, the fragment ion of ofloxacin is 261.0 m/z and 221.0 m/z, the fragment ion of metronidazole is 314.0 m/z and 231 m/z, and the fragment ion of metronidazole is 245.0 m/z and 203 m/z.
The presence of a minor fragment ion at m/z 120 further indicated the existence of cysteine.
HRMS provides accurate mass measurement, narrowing the possible elemental composition for each fragment ion and increasing the reliability and efficiency of data processing (23-27).
The MS/MS spectrum shows the most abundant fragment ion at m/z 353, indicating the loss of rhamnose moiety.
Peaks 10 and 11 exhibited the same [[M-H].sup.-] ions at m/z 593 and fragment ion at m/z 285 [[[Y.sub.0]].sup.-], indicating that they are isomers.
A fragment ion at m/z 306 refers to the deprotonated glutathione (GSH) moiety and CNLs of 120 and 146, indicating the presence of a rhamnoside group.
Herein, we developed an alternative method to determine protein KAc stoichiometries globally based on isotope labeling with the detection and quantification of a small diagnostic fragment ion for KAc found in tandem mass spectrometry (MS/MS) spectra.
The complex A showed base peak at m/z = 152 due to [C.sub.10][H.sub.17]N fragment ion and 4,4'-dimethoxy-2,2'-bipyridine ligand in the complex showed peak at m/z = 217 with relative intensity of 25%.
The ESI-MS/MS spectra showed [[M-H] .sup.-] at m/z 515.5, fragment ion [[M-[C.sub.9][H.sub.6][O.sub.3]].sup.-] at m/z 354.1, and fragment ion [MH- 2C9H6O3]- at m/z 191.2 (Figures 2(c), 2(d), 2(e), and 2(f)).
Protein mass: 321.5 Da Fragment ion calculator results Sequence: N-Ala-Phe-Cys-C Fragment ion table, monoisotopic masses Seq No.