title: Instrumental aspects of positive and negative ion chemical ionization mass spectrometry.
abstract: Differences in recording positive and negative ion chemical ionization mass spectra on a quadrupole mass spectrometer are discussed. An analog positive and negative ion electron multiplier detector is described which is well suited for a quadrupole instrument. This detector significantly reduces baseline noise in the negative ion mode and improves positive ion high mass sensitivity.
mesh_terms: D007477:Ions; D013058:Mass Spectrometry / Q000295:instrumentation*
chemical_list: D007477:Ions