Benefits of Chemical ionization (CI)

[adam-ladak]

Most people we talk to use electron ionization in GC-MS analysis. I am sure some of you are using chemical ionization for your analysis. Which application area do you find this ionization mode is best for and what are the benefits? 

[Dom_GC_Orbitrap]

Great question Adam and it will be interesting to hear the views. For GC Orbitrap where frequently the objective is to identify an unknown peak in the data, chemical ionization becomes essential to identify which ion in the spectrum is the molecular ion usually present as an adduct  (M+H, M+C2H5, M+C3H5). With only EI either at standard 70 eV or lower eV (<40) it's not always possible to sure you have a molecular ion in the spectrum or a high mass fragment.

[Dr_Stegemann]

Hey Adam,

i guess the most important use for CI will be the analysis of chlorinated paraffines which become more and more important. But otherwise it is really powerfull in combination with EI on a GC-Orbitrap to characterize unknowns.

Kind regards

Thomas