London, Jan 16 (IANS) Scientists have come up with a way of tagging products, including drugs and food, to tell the genuine from the fake and also trace the source of explosives even after detonation.

“This technology is applicable to the invisible tagging of manufactured substances and objects such as explosives, jewellery, artwork, foods and medicines, which helps to prevent fraud and counterfeiting,” said Jose Ignacio Garcia Alonso from the University of Oviedo in Spain.

“Through simple analytical techniques, a product can be traced from its origin and any possible illegal uses can be detected,” he added, according to the journal Analytical Chemistry.

Based on the addition of isotopes, the technique can also be used to trace explosives even after they have been detonated.

The technique consists of adding two stable (non-radioactive) isotopes (types of the same chemical element but with a different number of neutrons) at an established ratio to the object that is to be followed. Then, with an instrument called a mass spectrometer, a sample can be verified as having the predefined isotope ratio.

The researchers have applied this method to gunpowder, as an example of an explosive, by adding two isotopes of tin (Sn117 and Sn119).

After preparing three different mixes - each with differing isotopic proportions so that they can be distinguished from one another - the results reveal that even after detonation, the added tags can still be detected in the remains.

Alonso states that “such a procedure can be used in tagging explosives for civil or military use and can even go as far as identifying the product used in a terrorist attack”.