Small molecules
- Electron Ionization (EI)
- Chemical Ionization (CI)
- Atmospheric Pressure Chemical Ionization (APCI)
- Field Ionization (FI)
Small or large non-volatile molecules
- Electrospray Ionization (ESI)
- Matrix-assisted Laser Desorption Ionization (MALDI)
- Field Desorption (FD)
- Liquid Injection Field Desorption Ioniztion (LIFDI)
- Fast Atom Bombardment (FAB)