Flowing Atmospheric-Pressure Afterglow (FAPA), the Plasma-based Source for your ADI-MS Needs
Plasma-based ambient mass spectrometry sources are a very promising group of sources that, despite having a similar basic mechanism, all utilize very different geometries and discharge types to achieve desorption and ionization. A particularly promising source is the flowing atmospheric-pressure afterglow (FAPA) that has been developed within the Hieftje lab at Indiana University. In this chapter we explore the development, characterization and applications of the FAPA source. Fundamental examinations into reagent formation and optical-emission characterization provide insight into matrix effects and the He discharge itself. Schlieren imaging is also used to better understand ambient mass transport. A wide variety of FAPA practices are also presented, including the successful coupling of gas chromatography, capillary electrophoresis, laser ablation and a droplet-based sample-introduction system. Applications for detection of pesticides, explosives, drugs and atomic species are shown as well; additionally, chemometric methods coupled with the FAPA source successfully identified polymer types and counterfeit electronic components.