A pulsed corona discharge switchable high resolution ion mobility spectrometer-mass spectrometer

Area of Science:

• Analytical Chemistry
• Physical Chemistry

Background:

• Traditional 63Ni ionization sources have limitations.
• Development of alternative ionization sources is crucial for advanced analytical techniques.

Purpose of the Study:

• To introduce and characterize a pulsed corona discharge ionization source as a replacement for 63Ni sources.
• To investigate the reactant ion peaks generated by this new source in an ion mobility spectrometer-mass spectrometer system.

Main Methods:

• Assembly of a pulsed corona discharge ionization switchable high-resolution ion mobility spectrometer-mass spectrometer.
• Characterization of reactant ion peaks using mobility spectra, atmospheric chemical ionization mass spectra, and selected-mass mobility spectra.
• Ammonia doping in air with controlled water content for positive and negative mode analysis.

Main Results:

• In positive mode, observed ions were primarily [1(H2O)nNH4]+ and [(H2O)n(NH3)NH4]+ with ammonia doping.
• Negative mode analysis revealed complex ion formation, including [(H2O)nO2]-, [(H2O)nCO3]-, [(H2O)nHCO3]-, [(H2O)nCO4]-, and [(H2O)nNO3]-.
• Sufficient oxygen-based species were detected in negative mode to support analytical applications.

Conclusions:

• The pulsed corona discharge ionization source is a viable alternative to 63Ni sources for ion mobility spectrometry.
• The characterized ion species provide a basis for understanding and utilizing this ionization method in complex atmospheric analyses.
• The developed IMS-MS system demonstrates capability for detailed spectral analysis of ion populations.