Swab touch spray ionization (STSI) is an ambient ionization method that offers real-time analysis, requires no sample preparation, and can be paired with a portable ion trap mass spectrometer for <i>in-situ</i> analysis. STSI utilizes a rayon tipped swab that has an aluminum wire applicator handle which can be simply swabbed over the area of interest. The swab, after contacting the surface of interest, has solvent applied to the rayon tip and a high voltage applied to the aluminum handle. This process creates the ions that the mass spectrometer will use to determine if the analyte of interest is present. The swabs utilized in STSI are commercially available, they are sterile and they are individually packaged to prevent contamination, which make them ideal for forensic and defense applications. The swabs are additionally forensically feasible as they are sealed prior to delivery by the vendor with a tamper proof label. Here we have shown that this ambient ionization method allows for the direct swabbing of the hands of suspected and a variety of other surfaces for the trace residues of explosives and organic gunshot residues.  Traditionally, these compounds have long been analyzed by a number of instrumental techniques, many which involve extensive sample preparation or have lengthy analyses times. Finally, presented here is two modular STSI sources that remove the barrier to other laboratories implementing it as they are low cost, reproducible system that can be coupled to most mass spectrometers, both portable and benchtop.

Swab touch spray ionization mass spectrometry for rapid analysis of trace residues of forensic relevance

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.