Substances in suspicious packages exposed by Raman during daylight

Explosives, drugs and pesticides hidden in packages can be detected under normal light by spatially offset Raman spectroscopy (SORS), providing another weapon for the security services. SORS has been used to examine packages in a darkened lab but scientists in Australia have now adopted the technique so that it works under different conditions like fluorescent light, incandescent light and daylight, as they explain in the Journal of Forensic Sciences.

The system was demonstrated by detecting explosives precursors (ammonium nitrate, sodium perchlorate and hydrogen peroxide), a drug powder (acetaminophen) and a pesticide (chlorpyrifos) that were wrapped in high-density polyethylene containers like shampoo bottles, cotton fabric or a blue paper envelope. In all cases, the chemicals were identified by comparison with their reference spectra within one minute.

The ability to detect suspicious substances inside opaque packaging under real lighting conditions means that the device has the potential to be used in the field at airports, mail distribution centres and custom points.