Electron Ionization Sources: The Basics
July 01, 2006
The ion source is the heart of the mass spectrometer. In the ion source, ions are created from gas-phase neutral sample molecules, or preformed ions are extracted from solutions, and then sent into the mass analyzer of the instrument. The electron ionization (EI) source was the first source widely used for organic mass spectrometry (MS), and design, development, and optimization of this source are all the result of the work of many of the early pioneers of MS.