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Updated: Jul 14, 2026

Determination of the Gas-phase Acidities of Oligopeptides
Published on: June 24, 2013
Factors that impact the vacuum ultraviolet photofragmentation of peptide ions
Matthew S Thompson1, Weidong Cui, James P Reilly
1Department of Chemistry, Indiana University, Bloomington, Indiana 47405-4001, USA.
Abstract:
Several groups have investigated the photodissociation of peptide ions with ultraviolet light. Significant differences have been reported with 157 and 193 nm excitation. Recent studies have shown that the mass analyzer can also influence the observed photofragment distribution. Comparison of experiments using different peptides, wavelengths, and mass analyzers is undesirably complicated. In the present work, several peptides are analyzed with both 157 and 193 nm photodissociation in tandem-TOF and linear ion trap mass spectrometers. The results indicate that the fragment ion distribution can be influenced by both the photodissociation wavelength and the mass analyzer. The two wavelengths generate similar spectra in an ion trap but quite different results in a tandem-TOF instrument.
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