Bomb detector

A scientist at the Hebrew University of Jerusalem has discovered a way to literally catch terrorists red-handed.


A new chemical spray detector developed by Prof Joseph Almog of the Hebrew University’s Casali Institute of Applied Chemistry detects the home-made explosive urea nitrate.  When sprayed on cotton swabs taken from the hands of an individual who has had recent contact with urea nitrate, the chemical will turn a blood red hue.


Urea nitrate is a powerful improvised explosive, frequently used by Palestinian terrorists in Israel. It was also used in the first World Trade Center bombing in New York in 1993. Non-professionals can prepare large amounts of this material in ‘back-yard’ facilities, which have subsequently been used in improvised mines and in suicide bomber belts, the devastating results of which have killed over a hundred people in Israel alone.


Urea nitrate is a colourless crystalline substance that looks very much like sugar, which makes it very difficult to detect. The development of a colour test will therefore be a significant aid to forensic scientists. The test is based on the formation of a red dye in the chemical reaction between p-dimethylaminocinnamaldehyde and urea nitrate under neutral conditions.


Although instruments do already exist to detect urea nitrate, they are sophisticated and quite expensive. According to Prof Almog, his spray can detect minute traces of the improvised explosive on hands of suspects, door handles, luggage containers and vehicles, and it can distinguish between sugar or any innocent looking powder and urea nitrate.


Prof Almog, who said the spray detector is easy to use and inexpensive, sees it being adopted as a standard arsenal of law enforcement agencies, security services, and the military and at certain check-points at air and sea ports.