Early in 2005, the National Commission on Terrorist Attacks upon the United States, known as the 9/11 Commission, recommended that Congress and the Transportation Security Administration give priority attention to screening airline passengers for explosives.

No sooner said than done. Chemists at Purdue University have come up with a fast, portable, reliable way to detect residues that could indicate the presence of explosives and other hazardous materials inside luggage.

According to the researchers, the portable mass spectrometer can determine the presence of trace quantities of chemicals — such as those found in biological and chemical warfare agents, as well as several common explosives — on a surface within a few seconds.

The method uses a tool common in many chemistry and biology labs called a mass spectrometer that has been modified to analyze samples directly from the environment rather than requiring the lengthy pre-treatment that laboratory mass spectrometry samples typically require.

“No portable device is currently on the market that can analyze samples in this manner,” said R. Graham Cooks, a professor of chemistry in Purdue's College of Science.

Cooks's team had previously developed a prototype device that detects nanogram-sized samples, but with recent improvements the device has proven successful at detecting at the picogram (trillionths of a gram) level in lab tests, about 1,000 times less material than previously required. Cooks says he thinks a portable tool based on the technology could prove valuable for security in public places worldwide.

“In the amount of time it requires to take a breath, this technology can sniff the surface of a piece of luggage and determine whether a hazardous substance is likely to be inside, based on residual chemicals brushed from the hand of someone loading the suitcase,” he said.

The technology could be useful in screening suspect packages in airports, train stations and other places where there have been problems in the past. Because the technology also works on other surfaces, such as skin and clothing, it could help determine whether an individual has been involved in the handling of these chemicals, Cooks says.

Mass spectrometry is the analytical mule in chemistry labs because the machines can deliver highly accurate analyses of substances. First responders often use the devices to test suspicious looking residues. However, most mass spectrometers are cabinet-sized machines that require samples to undergo hours of intensive preparation before testing, making it unsuitable to test large numbers of containers quickly.

With the Purdue technology, it may now be possible to analyze samples rapidly, without any pretreatment. It has already been used to analyze pharmaceuticals at up to three samples per second.