title: Enhanced analysis of poly(ethylene glycols) and peptides using thermospray mass spectrometry.
abstract: The effects of a needle-tip repeller electrode on thermospray mass spectra of poly(ethylene glycols) and peptide samples have been studied. A significant increase in ion current was observed for increased repeller potentials in the low-mass region (m/z 300 to m/z 1100) and the high-mass region (m/z 1100 to m/z 1900). The change in ion current is due to a change in ion extraction efficiency because of increased ion diffusion rates. The amount of peptide sample needed for direct injection studies was decreased 1 to 2 orders of magnitude by using an ion source with both a needle-tip repeller electrode and a restricted vaporizer probe tip.
authors: S W
authors: SW
authors: Fink
authors: R B
authors: RB
authors: Freas
mesh_terms: D004566:Electrodes; D007477:Ions; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D010455:Peptides / Q000032:analysis; D011092:Polyethylene Glycols / Q000032:analysis
chemical_list: D007477:Ions; D010455:Peptides; D011092:Polyethylene Glycols