The current state of the science to detect explosives involves the search for particle residues using methods such as surface swipes or pulses of air that dislodge particles. Collected particles are then heated and vaporized for analysis. Particle collection involves imprecise manual sampling of luggage and similar objects of interest. Vapor detection would be a preferred sampling method; however, many explosive compounds have very low vapor pressures. When it comes to low-volatility compounds, which release very small amounts of vapor, even ultra-sensitive detection methods struggle. In order to be deployed, current methods for vapor detection would require extensive pre-concentration and likely tens of minutes or longer to detect such low-volatility compounds.

PNNL's award-winning trace detection technology provides reliable, real-time detection of explosives. Instead of collecting explosives particles, the tailored chemistry approach detects and identifies vapors of even very low-volatility explosives at ambient temperature and without sample pre-concentration. The technology has been demonstrated to detect explosives compounds such as RDX, PETN, nitroglycerine, and tetryl, along with plastic explosives that contain these materials from a fingerprint-sized sample at levels less than 25 parts per quadrillion.

The technology involves pulling an air sample stream and ionizing it within a reaction region in an atmospheric flow tube at pressures of at least 100 Torr (0.13 atm). The ionized sample moves to a mass spectrometer for ion detection and identification. The reaction process selectively increases the signal for the explosive vapors of interest. Analysis happens in less than 5 seconds.