Regulated in situ generation of molecular ions or protonated molecules under atmospheric-pressure helium-plasma-ionization mass spectrometric conditions

Rekha Gangam, Julius Pavlov, Athula B. Attygalle

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

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.]

Original languageEnglish
Pages (from-to)1252-1255
Number of pages4
JournalJournal of the American Society for Mass Spectrometry
Volume26
Issue number7
DOIs
StatePublished - 22 Jul 2015

Keywords

  • Helium-plasma ionization
  • HePI
  • Molecular ions
  • Protonated species

Fingerprint

Dive into the research topics of 'Regulated in situ generation of molecular ions or protonated molecules under atmospheric-pressure helium-plasma-ionization mass spectrometric conditions'. Together they form a unique fingerprint.

Cite this