Microwave plasma torch - Atmospheric-sampling glow discharge modulated tandem source for the sequential acquisition of molecular fragmentation and atomic mass spectra

A modulated tandem source consisting of a microwave plasma torch and an atmospheric-sampling glow discharge is investigated as a means of generating atomic and molecular mass spectra in a rapid, sequential manner. Conceptually, the pair operates by using the microwave plasma torch to produce atomic ions, and the atmospheric-sampling glow discharge for production of molecular fragmentation mass spectra. The mass spectra of several volatile organic compounds representative of both atomic and molecular modes of operation are presented, and the latter directly compared to mass spectra produced by an electron-impact ionization source. Unique aspects of the experimental construction and performance of this pair are considered.