Characterization of multipole storage assisted dissociation: Implications for electrospray ionization mass spectrometry characterization of biomolecules

Ions accumulated in an rf-only multipole for extended periods of time prior to mass analysis can experience a significant degree of fragmentation and produce mass spectra which do not reflect the true nature of the intact ana lyte(s). This phenomenon, termed multipole storage assisted dissociation (M SAD), places constraints on the maximum number of ions which can be accumul ated in the multipole storage device as a result of its finite space charge limit. This phenomenon can be exploited to produce dissociation spectra th at are dominated by fragment ions providing important sequence/structure in formation. In this work we further explore MSAD and characterize parameters including accumulation time, source pressure, and the electrostatic config uration of the multipole storage device, which mediate the phenomenon. Oper ating parameters are identified that can either enhance or eliminate the ph enomenon. (J Am Soc Mass Spectrom 2000, 11, 1-9) (C) 2000 American Society for Mass Spectrometry.