An ultrasensitive technology detects explosive vapors, deadly chemicals, and illicit drugs and works in seconds. The ion chemistry technique initially identified RDX — a common explosive compound — at 10 parts per quadrillion (ppq). The original technology also identified explosive compounds such as C-4, PETN, Semtex, nitroglycerin, and tetryl. The system was enhanced to detect many more explosive vapors, including TNT, as well as vapors emanating from toxic chemicals similar in structure to nerve agents. The latest enhancement is the ability to detect vapors from illicit drugs such as fentanyl, methamphetamine, and cocaine.

The technology works by sucking an air sample into a narrow metal tube. Inside the tube, the sample collides with chemical ions and creates a positive or negative charge on the way toward the inlet of a mass spectrometer. The mass spectrometer measures, or detects, the ions of interest based on their charge and mass. Users can adjust the ionization source to selectively react with the compound of interest.

Common security screening methods rely on contact swabs or swipes — a physical sample that is then heated and analyzed. These methods are intrusive, labor-intensive, and time-consuming. Sniffer dogs are an alternative but in addition to needing rest, they're also expensive to train and care for.

During ionization, electrically neutral atoms or molecules are converted to electrically charged ions. This electric charge is necessary for detection in a mass spectrometer. It comes down to a competition between sensitivity and selectivity — how many collisions are needed to detect a certain ion or chemical vapor. In the new system, the sample inlet and the ionization source were moved further away from the spectrometer. This created more distance — and therefore time — for the chemical ions and sample molecules to bump into each other and react. The small leap from milliseconds to a few seconds made all the difference.

The technology was advanced further for greater sensitivity and the ability to detect more types of compounds. The sensitivity of the technology became the bridge to detecting vapors from organophosphates — or deadly chemicals — and narcotics. The system cannot see everything at once and must be tailored or customized for the substance(s) of interest.

For more information, contact Nick Hennen at This email address is being protected from spambots. You need JavaScript enabled to view it.; 509-554-4533.


Tech Briefs Magazine

This article first appeared in the February, 2020 issue of Tech Briefs Magazine.

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