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Molecular weight determination by cationisation
Author(s) -
Röllgen F. W.,
Schulten H.R.
Publication year - 1975
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210100811
Subject(s) - protonation , molecule , fragmentation (computing) , chemical polarity , chemistry , ion , anode , desorption , adsorption , thermal desorption , common emitter , field desorption , analytical chemistry (journal) , chemical physics , materials science , electrode , organic chemistry , ionization , optoelectronics , computer science , operating system
In General cationised molecules are more stable than redical molecular ions or protonated molecules. The fragmentation of the polar molecules resulting from a cationsation by for instance alkali ions, has a higher activation energy than splitting off fuctional groups after a protonation. Cationisation is therefore an intersting tool for the determination of molecular weights. Three different methods for achiving a cationisation are described and discussed: (1) field‐indiced cationisation at low anode temperatures using a heterogenous reaction of the molecules in the gas phase with molecules of a salt in the adsorption layer on the field anode; (2) a largely thermally induced catisation at high emitter temperatures and low electric fields; (3) a cationisation, causing less thermal excitation to the molecules, using the field desorption technique.