TY - JOUR
T1 - Regulated in situ generation of molecular ions or protonated molecules under atmospheric-pressure helium-plasma-ionization mass spectrometric conditions
AU - Gangam, Rekha
AU - Pavlov, Julius
AU - Attygalle, Athula B.
N1 - Publisher Copyright:
© 2015 American Society for Mass Spectrometry.
PY - 2015/7/22
Y1 - 2015/7/22
N2 - In an enclosed atmospheric-pressure helium-plasma ionization (HePI) source engulfed with dehumidified ambient gases, molecular cations are generated from compounds such as toluene, bromobenzene, and iodobenzene. Evidently, the ionization is effected by a direct Penning mechanism attributable to interactions of the gas-phase analyte with metastable helium atoms. It is widely known that secondary ions generated from ambient gases also play an important role in the overall ionization process. For example, when the ambient gases bear even traces of moisture, the analytes are ionized by proton transfer reactions with gaseous H3O+. In this study, we demonstrate how a controlled variation of experimental conditions can manipulate the abundance of molecular ions and protonated molecules in a HePI source. [Figure not available: see fulltext.]
AB - In an enclosed atmospheric-pressure helium-plasma ionization (HePI) source engulfed with dehumidified ambient gases, molecular cations are generated from compounds such as toluene, bromobenzene, and iodobenzene. Evidently, the ionization is effected by a direct Penning mechanism attributable to interactions of the gas-phase analyte with metastable helium atoms. It is widely known that secondary ions generated from ambient gases also play an important role in the overall ionization process. For example, when the ambient gases bear even traces of moisture, the analytes are ionized by proton transfer reactions with gaseous H3O+. In this study, we demonstrate how a controlled variation of experimental conditions can manipulate the abundance of molecular ions and protonated molecules in a HePI source. [Figure not available: see fulltext.]
KW - Helium-plasma ionization
KW - HePI
KW - Molecular ions
KW - Protonated species
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U2 - 10.1007/s13361-015-1102-5
DO - 10.1007/s13361-015-1102-5
M3 - Article
AN - SCOPUS:84934946233
SN - 1044-0305
VL - 26
SP - 1252
EP - 1255
JO - Journal of the American Society for Mass Spectrometry
JF - Journal of the American Society for Mass Spectrometry
IS - 7
ER -