Charge stripping mass spectrometry

The application of electrospray ionization (ESI) to macromolecules was first described by Yamashita and Fenn in 1984, and he later applied this technique to the study of proteins in 1988. In ESI, charged droplets of protein were produced and the solvent was stripped away, leaving only the free protein ion. In 1987, Tanaka demonstrated that laser pnlses from a low-energy nitrogen laser could be used to ionize proteins from a surface. As described in a paper presented during the Second Japan-China Joint Symposium on Mass Spectrometry, proteins are desorbed from a glycerol matrix containing cobalt powder. The cobalt powder was necessary to increase absorption of the laser photons. ... 

The protonation of the methyleneiminium cation gives rise to the superelectrophilic methyleniminium dication, 19, which is a gitonic 1,2-dicationic species (carbenium ammonium species). Such a carbodication has been observed by charge stripping mass spectrometry by Schwarz and coworkers.Olah and coworkers have shown by theoretical calculations that the carbenium ammonium species, 19a, is 27.6 kcal/mol more stable than the three-center two-electron (3c-2e) bonded structure, 19b. ... 

Schwarz and coworkers258 have been successful in generating the diatomic dication SiF2+ by charge-stripping mass spectrometry (equation 43)259-262. 

Stmctures of both imidazol-2-ylidene 105 and imidazol-4-ylidene 106 (Scheme 22) were generated as the corresponding ions 105 and 106 by neutralization-reionization (NR) and charge-stripping (CS) mass spectrometry from 2-formylimidazole and 4,5-bis(methoxycarbonyl)imidazole, respectively. Relative to imidazole, the collision-induced dissociation (CID) mass spectmm of 105- shows an intense peak at miz 42 that is attributed to the loss of acetylene, thus supporting the 2-carbene ion stmcture. The CID spectra of 106- show a strong peak at mjz 29 and a weak peak at mjz 16 <1997AGE 1478>. 

Ast, T., Porter, C. J., Proctor, C. J. and Beynon, J. H. Charge stripping reactions in mass spectrometry ionization energies of some mono- and disubstituted benzene ions. Glas. Hem. Drus. Beograd 46 135-151, 1981. 

---