Detect-and-go: The briefcase-sized laboratory allows bomb chemicals to be analysed in minutes rather than weeks.
Credit: Australian Centre for Research on Separation Science
SYDNEY: Australian chemists have developed a portable device that can quickly determine the chemical signature of homemade bombs like those used in the 2005 London bombings. The technology would rapidly provide the information investigators need to hunt down terrorists.
"Bombs leave characteristic chemicals, and you can fingerprint that residue," said analytical chemist Paul Haddad, director of the Australian Centre for Research on Separation Science in Hobart, Tasmania and lead author of a study detailing the technology in the journal Analytical Chemistry.
However, to get that chemical fingerprint, investigators currently have to send away samples to a laboratory that might take weeks to return a result, Haddad said, hampering police investigations. His team's device could now reduce that waiting time to less than ten minutes.
Violently volatile
For homemade bombs, heavy-duty explosives like trinitrotoluene (TNT) are not typically used, because vast quantities are required, he added, potentially rousing the suspicion of authorities. Instead, illicit bombs are typically made from commonly available chemicals – such as ammonium and nitrate that are found in fertilisers – which can explode violently when reacted with volatile compounds.
The chemical signatures of these chemicals are left on the wreckage after a bomb explodes and can be detected on people or objects they have come into contact with. As soon as investigators determine which explosives a bomb is made of, they can start the hunt for the people who procured the chemicals.
To determine the makeup of a bomb, the device uses a process called capillary electrophoresis to separate out up to 27 types of molecules from a sample in just one test. Investigators collect a swab from the wreckage of a bombsite and mix it with water. The mixture gets injected into a capillary tube about the size of three human hairs where an electrical voltage is applied to it. The voltage separates the particles based on their unique size and charge.
Significant improvement
The portable device is much faster and a significant improvement on existing technology, because it allows forensic experts to determine the chemical signature of a bomb at the site of an explosion. On-site testing could take place in just nine minutes, Haddad said, and would eliminate potential contamination or degradation of the sample.
"What we've got is a briefcase-sized instrument that you can fire off straight away," he said. "If in 10 minutes you can hunt for perpetrators, you're on the right track."
These scientists are "developing results that are of significant interest for operational labs," commented forensic scientist Chris Lennard, a former Australian Federal Police officer now based at the University of Canberra. "As far as we're aware it's the first work of its type that's looked at electrophoresis of inorganic residues and shown potential."
