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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."
...detects the presence of musketeers!
THL phish sticks
All I keep hearing about is knee jerk reactions to a sad but relatively trivial event in Boston.
There is an old design for a flint powered detector similar to a more modern piezo-electric black powder detector.
Lets not forget the BATF detector which supplies its own sample and has a 100% detection rate.
Get ready for the massive amounts of false positives. You went to the firing range last Tuesday? Terrorist Scum!
Bullets are made out of black powder? All the ones I've used have been made out of lead or copper. How do those black powder bullets hold together?
Reporters, please learn the difference between:
Ammunition and bullets
Magazines and clips
Automatic vs Semi-Automatic
etc, when talking about firearms.
Black powder is perfectly legal.
Why should black powder residue constitute probable cause of anything, if possession and use of black powder is actually legal?
In theory, I could go shooting my historical weapons that use black powder, which is also perfectly legal, or go to a war-between-the-states reenactment, and then walk through downtown Boston. Nevermind, that would be outside the ordinary, prescripted "safe area" of human activity that "most normal people" do, and therefore suspicious and therefore probable cause. Got it.
I'd hate to come across as pedantic, but...
An ammunition cartridge is composed primarily of:
Bullet: The projectile that is ejected from the muzzle of the firearm at high speed.
Propellant: The chemical explosive that is burned to propel the bullet.
Primer: The component that chemically generates heat when struck with sufficient force, igniting the propellant.
Casing: Just what it sounds like, the part that holds everything together.
Now, to keep this from being entirely off-topic...
Modern ammunition cartridges do not contain black powder. They contain smokeless powder. Much like "clips" and "magazines", or "diesel" and "gasoline", these are two different things that are not interchangeable.
Chuuch. Preach. Tabernacle.
Black powder can be found almost everywhere, even in societies that do not have a gun-fetish. Every little firecracker has it in it. These detectors would cause so many false positives as to be not only absolutely worthless, they would have negative value as they waste massive amounts of resources.
But I get it, the US administration, and under its tutoring the US population, have lost all rationality when it comes to "terrorism" a long time ago. The next bombing (and it will happen) will just cause as much useless actionism and more steps towards a police-state as this one did. And if it takes too long for the next bombing to happen, the FBI will arrange a fake one, as they have done several times before.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
This would be great to create false positives. Just sprinkle some on random people to create as many false positives as possible.
Then when they turn the system off, do some small attack and then when they turn it back on, start with the false positives again.
remember: terrorism isn't about killing people, it is about spreading terror. The actual limiting of peoples freedom will be done in congress. Installing this means the terrorists have won.
Don't fight for your country, if your country does not fight for you.
Black powder is an ancient explosive, not to mention easy and cheap to make. We even did it in one of my science classes.
:p
(Sure, that was back in the 80s when chemistry in a science class meant you actually mixed and tested various chemicals instead of just watching a video on the structure of polymers as it pertains to the plastics industry, but still.)
Also, gunpowder is not that powerful, and there are plenty of others with more bang that are nearly as easy to make.
Bet those sensors go absolutely berserk during July.
Of course, if someone wanted to cause trouble, just toss a handful of power into the wind blowing on a crowd anywhere they have those sensors.
Any security system that can be so easily swamped with false positives (the false positive is not that the gunpowder was detected, but rather that they were a threat, had anything to do with it, or had any knowledge regarding it at all.
And that's assuming it's only going off on gunpowder, because if it goes off on sulfur, even an egg salad sandwich or certain types of antibiotics could cause a lockdown. How many of those will occur before someone realizes that trying to detect a common element is not security.
Just hang on a minute.
"Smokeless powder" (nitrocellulose) pretty much replaced gunpowder (sulfer, charcoal, and potassium nitrate) in firearms over an hundred years ago, except for historical reproductions. And even those replicas of old firearms largely use alternative propellants that are engineered to have the same bang per volume of gunpowder (as the propellant is measured by volume during reloading). The "gunpowder" in fireworks is not the same propellant used in modern firearms. Equating the two could lead to some confusion. This distinction will be entirely lost on the congressional floor, but as nerds, we should be aware of it.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
What this appears to be talking about is how at the airport they now swab your carry-on luggage and put it in a machine. I don't think these boston folks would have been though any "swabing" checkpoint so the existance of a device that did this probably would not have made anyone "safer" in this case (or any similar non-airport/govt-building checkpoint situation).
For those curious, the idea behind an IMS (ion mobility spectrometer), is that you ionize your sample (well sort of, you have water or other liquid vapor with ions dissolved in it, not just pure ions in air or in a vaccum) and waft them into a drift tube and use fact that these ionized vapors have slightly different masses so they have different mobility under an electric field. The "spectra" of the mobility under this electric field helps to identify the original chemicals in the swab.
The specific problem they are trying to solve with black powder is that the ions formed by Sulphur (atomic mass 32) and Oxygen (atomic mass 16) are very difficult to disambiguate for a clean detection signal (since O2n- and S1n- have about the same mass).
The common method of disamgibuating is to add solvents or chemical reagents before ionization. AFAIK, in the case of Oxygen interference, a common way to change the ionic signature is to add dichlorolmethane CH2CL2 and the resulting reaction usually exchanges O2- ions for CL- ions (which is enough different than sulphur ion to make it easy to detect), but unfortuantly, dichloromethane also has a side effect of inhibiting the formation of various Sulphur ion allotropes (i.e., different number of sulphur atoms in the ion). So these folks apparently came up with a technique where you ionize first (avoiding the problem with CH2CL2 and sulphur ion formation) and then pass all the ions through a CH2CL2 "titration region" in the drift tube (effectively replacing many of O2- ions that mask the sulphur ion signature with Cl- ions).
Of course the devil is in the details which I haven't read about yet...
I hear there's quite a market for them.
Just a side note because it's making me nerdrage :) TFA asserts "Used in fireworks and bullets, the explosive substance is both deadly and widely available." Assuming that they are actually talking about "black powder" I think this was an included invention by the writer.
Manufactured ammunition (with a very few niche and very expensive exceptions) hasn't used "black powder" for its loads for over 100 years. Modern ammo uses "smokeless" powders with a variety of chemical compositions based around nitroglycerin and 1or 2 other nitro based chemicals. These should be easily detectable with existing sniffers that are looking for nitrates. So if a day on the range was going to get me hauled in at the TSA line, well were already past that.
Pyrodex and other Black Powder substitutes are more commonly used by muzzleloader hunters and Pyrodex is "smokeless powder" based and formulated for the lower power of black powder explosions. I should also be easily detectable.
Garden variety "buy it a supermarket go-bang fireworks" use perchlorate based fuel as far as I know. I don't know how detectable it is or how chemically similar it is to black powder off the top of my head. But I'd guess it's not and would prefer it to be detectable.
On the other hand I CAN buy black powder by the 16oz can with cash. I think it would be good thing if the chemsniffers could detect it.
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There were bomb-sniffing dogs working the marathon - they were pulled once the elite runners had gone through and the dignitaries had left.
Please help metamoderate.
Actually, making "good" black powder isn't easy. Any idiot can mix sulfur, sodium nitrate and charcoal and make a sort of rapidly burning mixture. But it wouldn't be real black powder. You need to mix them and grind them together (a nontrivial process if you don't want to have it ignite), then you mix it with the right amount of water, make a paste, let it dry into a solid cake, then break the cake up in a way that makes nice sharp edged particles, as opposed to just grinding it into spherical dust particles.
I suspect that the bare mixture would probably work in an improvised device, but so would sugar and perchlorate, or Pyrodex, or SolidOx and fuel or.. you get the idea.. The idiots bombing abortion clinics used to favor fire extinguishers as their pressure vessel. A bit more expensive than a pressure cooker, but a lot less conspicuous. And they favored chlorate/fuel mixtures.