Three Ionization Modes

EI (Electron Ionization), PCI (Positive Chemical Ionization) and NCI (Negative Chemical Ionization) are the main ionization modes generally used in GCMS analysis. It is important to understand the features of each ionization method in order to select the most suitable one.

EI, electron ionization or electron impact, is the most common ionization method and is a powerful tool for both qualitative and quantitative analysis.