ABSTRACT
Ion optical devices that produce a beam of gas-phase ions from samples, mass spectrometers sort the resulting mixture of ions according to their massto-charge ratios or a derived property, and provide analog or digital output signals (peaks) from which the mass-to-charge ratio and intensity (abundance) of each detected ionic species may be determined. The analyte molecules
must
be ionized and the ions
must
be in the gas phase.
