New laser method helps detect hidden liquid explosives

Oxfordshire, UK--A new and powerful technique that can detect hidden liquid explosives through common plastic containers and glass bottles has been demonstrated by scientists from STFC's Rutherford Appleton Laboratory (RAL). The research is being reported in the latest issue of Analytical Chemistry.

There is real concern about the use of liquid explosives by terrorists, which has led to the current restrictions in place at airports. Current methods for detecting potentially dangerous materials are time-consuming and not always practical. The difficulty in detecting these substances is also compounded by the wide variety of packaging used by air travellers in which these explosives can be readily concealed.

The scientific paper, "Non-invasive Detection of Concealed Liquid Explosives using Raman Spectroscopy," by Charlotte Eliasson, Neil Macleod, and Pavel Matousek, reports on the successful application of a recently developed measurement technique using lasers that applies a novel approach to a conventional, trusted method for identifying materials. Spatially offset Raman spectroscopy' (SORS) was originally developed for medical and pharmaceutical applications but has now been demonstrated to work in security applications. The technique, which can be implemented using a hand-held probe, produces chemical information on liquids contained in transparent and diffuse plastic containers, including those made from colored materials.

Applications of this technology are not only limited to security; the detection of adulterated food products and beverages as well as use in quality control in the food, pharmaceutical and chemical industries are also being tested.

"This work is a fine example of how fundamental scientific research can come up with solutions to practical problems that concern every one of us," said Mike Dunne, director of the Central Laser Facility at RAL, where the research has taken place.

Matousek, the project team leader, noted that the technology is applicable to a wide range of problems. The researchers are now planning to develop the technology commercially through a new spin-out company, LiteThru Ltd., which will address additional commercial applications in pharmaceutical manufacturing, anti-counterfeiting, and medical diagnostics.