August 2008

National lab hits sensing trifecta

A new machine can detect explosive, chemical, and biological agents all at the same time.

A team of Lawrence Livermore National Laboratory (LLNL) researchers proved a three-in-one machine, or "universal point detection system," can work, said George Farquar, a postdoctoral fellow and physical chemist at the Lab's Glenn T. Seaborg Institute. The machine could help clear airplane passengers and screen baggage.

The team uses a mass spectrometry system to detect the presence of minuscule particles of explosives. Mass spectrometry identifies the chemical composition of a compound or sample on the basis of the mass-to-charge ratio of charged particles.

"We have found we can potentially detect an incredibly small quantity of material, as small as one dust-speck-sized particle weighing one trillionth of a gram, on an individual's clothing or baggage," Farquar said. "This is important because if a person handles explosives they are likely to have some remaining residue."

Using a system they call Single-Particle Aerosol Mass Spectrometry, or SPAMS, the Livermore scientists have developed and tested the technology for detecting chemical and biological agents.

The research expands SPAMS' capabilities to include several types of explosives used worldwide in improvised explosive devices and other terrorist attacks.

"SPAMS is a sensitive, specific, potential option for airport and baggage screening," Farquar said. "The ability of the SPAMS technology to determine the identity of a single particle could be a valuable asset when the target analyte is dangerous in small quantities or has no legal reason for being present in an environment."

The team conducted its explosives tests under laboratory conditions at LLNL last summer. "The tests went well. They show the potential to identify explosives in a field setting," Farquar said.

The early history of the three-in-one detection system started at LLNL in 1999 with the development of the Bioaerosol Mass Spectrometry (BAMS) system. This system can detect airborne biological pathogens and sound a warning in less than one minute.

In late 2005, Livermore researchers started work to expand the capabilities of BAMS to include chemicals and explosives, setting the stage for the new machine now called SPAMS.

"While this instrument started as a biological detector, we saw that it had the potential to do much more by detecting other threat agents, such as chemicals and explosives," Farquar said.

Nicholas Sheble ( writes and edits Automation Update.