ABSTRACT
The ions produced in the source are separated in the analyzer according to their mass-to-charge (m/ z) ratios. The Thomson unit (Th, named for a famous mass spectrometrist) corresponds to an m/ z ratio of 1; it is widely used in mass spectrometry. In a GC-MS context, we often speak too generally about mass measurement because z = 1 in electron ionization and positive chemical ionization and z = –1 in negative chemical ionization.
