@article{fdi:010058998,
  title = {{B}ehavior of {N}-oxide derivatives in atmospheric pressure ionization mass spectrometry},
  author = {{I}brahim, {H}. and {C}ouderc, {F}. and {P}erio, {P}ierre and {C}ollin, {F}. and {N}epveu, {F}.},
  editor = {},
  language = {{ENG}},
  abstract = {{RATIONALE} {I}ndolone-{N}-oxide derivatives possess interesting biological properties. {T}he analysis of these compounds using mass spectrometry ({MS}) may lead to interference or under-estimation due to the tendency of the {N}-oxides to lose oxygen. {A}ll the previous works focused only on the temperature of the heated parts (vaporizer and ion-transfer tube) of the mass spectrometer without investigating other parameters. {T}his work is extended to the investigation of other parameters. {METHODS} {T}he behavior of {N}-oxides during atmospheric pressure chemical ionization ({APCI}) and electrospray ionization ({ESI}) has been investigated using {MS}n ion trap mass spectrometry. {D}ifferent parameters were investigated to clarify the factors implicated in the deoxygenation process. {T}he investigated parameters were vaporizer temperature ({APCI}), ion-transfer tube temperature, solvent type, and the flow rates of the sheath gas, auxiliary gas, sweep gas and mobile phase. {RESULTS} {T}he deoxygenation increased when the vaporizer temperature increased. {T}he extent of the 'thermally' induced deoxygenation was inversely proportional to the ion-transfer tube temperature and auxiliary gas flow rate and in direct proportion to the mobile phase flow rate. {D}eoxygenation was not detected under {MS}/{MS} fragmentation and hence it is a non-collision-induced dissociation. {N}-{O}xides have the tendency to form abundant 'non-classical' dimers under {ESI}, which fragment via dehydration rather than giving their corresponding monomer. {CONCLUSIONS} {D}eoxygenation is not solely a 'classical' thermal process but it is a thermal process that is solvent-mediated in the source. {D}eoxygenation was maximal with an {APCI} source while dimerization was predominant with an {ESI} source. {T}herefore, attention should be paid to these molecular changes in the mass spectrometer as well as to the choice of the ionization mode for {N}-oxides.},
  keywords = {},
  booktitle = {},
  journal = {{R}apid {C}ommunications in {M}ass {S}pectrometry},
  volume = {27},
  numero = {5},
  pages = {621--628},
  ISSN = {0951-4198},
  year = {2013},
  DOI = {10.1002/rcm.6493},
  URL = {https://www.documentation.ird.fr/hor/fdi:010058998},
}