Crime investigators and first responders may now soon have an edge in confiscating and examining white powders found at potential crime scenes. Currently, touching the powders is thought to be dangerous or seen as compromising the evidence and, sending samples to a lab to be identified takes too long. But now, scientists at Heriot-Watt University have proved the concept that white powders have a unique ‘fingerprint’ that allows them to be identified instantly, using portable laser technology, hence solving the problem.
Professor Derryck Reid and his team from the university reported in Optics Express that they were able to identify 11 white powder samples using their infrared laser system. No samples or disturbance of the powders were required, and they could be identified from up to one metre away. Readily available, non-toxic powders like painkillers, nutritional supplements, stimulants and a simple sugar were selected for the experiment, although Reid believes the identification system will prove most useful for a different set of substances. According to him, the instant, accurate identification of white powders could be useful in a range of scenarios, such as detecting counterfeit pharmaceuticals, conducting foodstuff analysis or identifying hazardous material like explosive residue.
They made use of the concept that white powders have a color ‘fingerprint’ that can be seen using a process known as spectrometry. The powders have different chemical bonds and this affects how they absorb light. By analyzing the contrast between the infrared light the researchers beam at the powders, compared to what colors come back, they can identify individual chemicals and compounds. This has an obvious application for narcotics detection. There is an appetite for portable crime scene technology that can reduce the risks faced by personnel, while providing accurate and instant results.
The laser technology has recently been commercialized by Heriot-Watt spinout company Chromacity Ltd, so it’s now a short step to develop a directory of powder fingerprints that would allow users to quickly identify the powder that’s in front of them, without delay or danger. Chromacity, which designs and manufactures ultrafast lasers in Heriot-Watt University’s research park, has already miniaturized the laser system used in the experiment, meaning first responders and other users could have cutting edge laser technology in a package the size of a large briefcase.
Paper: White Powder Identification using Broadband Coherent Light in the Molecular Fingerprint Region