Collisionally-activated dissociation spectra of linear peptides in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Collisionally-activated dissociation (CAD) studies of linear peptides were performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Four different gases, viz. helium, nitrogen, argon and xenon, were introduced into a gas cell, installed close to the ion source of TOF mass spectrometer, to obtain high-energy CAD information. The CAD spectral patterns for the linear peptides obtained using the four gases were almost the same as each other. The fragments characteristically obtained in conventional high-energy CAD using tandem mass spectrometry were observed also in these spectra. A difference between CAD spectra and post-source decay product-ion spectra has been demonstrated.