The scientists believe that they have developed a method, called Paired Ion Electrospray Ionisation
(PIESI) that builds on existing mass spectrometry techniques to detect these extremely small metabolites and uses a chemical agent to bind to the minute pieces of steroid or amphetamine and make them more visible to the detector.
Current ionisation methods: The use of 18 specified ionisation methods in mass spectrometry, namely atmospheric pressure chemical ionisation (APCI), atmospheric pressure photoionisation (APPI), chemical ionisation (CI), desorption chemical ionisation (DCI), desorption/ionisation on silicon (DIOS), direct analysis in real time (DART), electron ionisation (EI), electrospray ionisation
(ESI), fast atom bombardment (FAB), field desorption (FD), field ionisation (FI), glow discharge (GD), inductively coupled plasma (ICP), ion attachment ionisation (IAI), matrix-assisted laser desorption ionisation (MALDI), negative ion electron capture (NIEC), thermal ionisation (TI), thermospray or other (more than 30 ionisation methods were identified in this market study).
The compounds in their breath were analysed by means of a technique called secondary electrospray ionisation
mass spectrometry (SESI-MS), which is capable of detecting extremely small elements of the chemicals present in their breath.