An analytical technique in which ions are separated
according to the mass/charge (m/e) ratio and detected
by a suitable detector. In a mass spectrometer a sample is ionized and the
positive ions produced are accelerated into a high-vacuum region containing
electric and magnetic fields. These fields deflect and focus the ions onto
a detector. A mass spectrum is thus obtained consisting of a series of peaks
of variable intensity to which m/e values can be assigned. Different molecules
can be identified by their characteristic pattern of lines.