Potential for an Atmospheric-Pressure Low-Power Microwave-Induced Plasma Ionization Source for Mass Spectrometry

The potential for using the microwave-induced plasma (MIP) as an ionization source is further explored. This source operates at atmospheric pressure, minimizing pumping problems and, through power and gas-flow adjustment, offers the possibility of selecting from elemental spectra to fragmentation spectra resembling those from electron impact sources. The effect of microwave power, carrier gas-flow rate, and injector-probe configuration in the production of fragment ions is demonstrated with the use of perfluorotributylamine and tetramethyltin. Initial potential for liquid-sample introduction to the MIP is accomplished by using a direct-injection nebulizer (DIN) at higher reproducibility levels than in earlier studies.