University of Liverpool Student Carl Fletcher and Mass Spec Analytical presented a Poster and summary presentation at the British Mass Spectrometry Society Ambient Ionisation Special Interest Group Meeting covering recently published research into using a Low Temperature Dielectric Barrier Discharge Ionisation Source for explosive detection.
The increasing threat from Improvised explosive devices (IEDs) requires an enhancement in our detection and screening capabilities. Current analytical security screening methods in public places traditionally rely on the combination of thermal desorption (TD) with ion mobility for the detection of illicit substances and explosive residues. Ambient ionisation methods such as DART and DESI are commercially available, but they both require either sample preparation, discharge and operate with quite a small surface area. It was decided that a plasma based ambient ionisation technique would be developed that operated in ambient air, with no solvents and with a much larger sampling surface area.
The poster and the paper that accompanies it examines a dielectric barrier discharge (DBD) low temperature plasma ion source with great potential for the detection of explosives in real-world applications. Thermally labile compounds may be detected at the same time as more stable compounds, eliminating the need to have different desorption temperature settings for different explosives groups. Four explosive types have been successfully detected using various mass spectrometers with reasonable detection limits, RDX (100 pg), PETN (100 pg), HMTD (1 ng) and TNT (5 ng). The DBD is a TRL-5 prototype that does not require any discharge gases, solvents, adduct forming reagents or chromatography thus, massively reducing sample preparation, consumable cost and analysis time whilst operating with a surface area of more than 500 mm2.
This is a collaboration between Mass Spec Analytical Ltd and the University of Liverpool.