New Device Sniffs Out Black Powder Explosives

sciencehabit writes "The Boston marathon bombers Tamerlan and Dzhokhar Tsarnaev reportedly purchased several pounds of black powder explosive before the bombing. Used in fireworks and bullets, the explosive substance is both deadly and widely available. It's also very hard to detect. Now, researchers have modified one bomb-sniffing device to accurately spot very small amounts of black powder, an advance that could make us safer from future attacks. What has prevented detection of black powder by IMS in the past, however, is that sulfur and oxygen -- which composes 20% of air—hit the detector at almost the same time. A strong oxygen signal can thus mask a small amount of sulfur, like what a bombmaker's dirty fingers might leave on a luggage strap. A group led by chemist Haiyang Li at the Dalian Institute of Chemical Physics in China modified an IMS to eliminate the oxygen signal. 'We have tested the sensitivity of TR-IMS, and its limit of detection of black powder can reach as low as 0.05 nanograms,' Li says."

Re:False Positives

[girlintraining]

Get ready for the massive amounts of false positives. You went to the firing range last Tuesday? Terrorist Scum!

It detects sulphur. Anyone who has used matches recently will be tagged as well.

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[account_deleted]

Comment removed based on user account deletion

Re:More niggling

[CrimsonAvenger]

Modern ammunition cartridges do not contain black powder [wikipedia.org]. They contain smokeless powder [wikipedia.org]. Much like "clips" and "magazines", or "diesel" and "gasoline", these are two different things that are not interchangeable.

A slight quibble:

blackpowder can be loaded into any casing and will work just fine (for certain values of fine - be VERY careful about loading). Note that the .45-70 cartridge was originally blackpowder, is now smokeless powder, but is the same size cartridge it always was, so can be loaded quite safely with 70 grains of black powder instead of whatever amount of smokeless it comes out of the box with.

Note that the above quibble really only matters to the few of us who own replicas of the 1873 Springfield .45-70 cavalry carbine (7th Cavalry used them at Little Big Horn, for reference) and feel the incredible urge to foul the barrels of our carbines for a more "realistic feel"....

Pointless - there were already bomb-sniffing dogs

[SuperBanana]

There were bomb-sniffing dogs working the marathon - they were pulled once the elite runners had gone through and the dignitaries had left.