Advanced explosives detector to sniff out previously undetectable amounts of TNT

Aug 08, 2012
Advanced explosives detector to sniff out previously undetectable amounts of TNT

With the best explosive detectors often unable to sniff out the tiny amounts of TNT released from terrorist bombs in airports and other public places, scientists are reporting a potential solution. Their research in ACS' journal Analytical Chemistry describes development of a device that concentrates TNT vapors in the air so that they become more detectable.

Yushan Yan and colleagues point out that TNT and other conventional explosives are the mainstays of terrorist bombs and the anti- that kill or injure more than 15,000 people annually in war-torn countries. In large, open-air environments, such as , train stations and minefields, concentrations of these explosives can be vanishingly small – a few parts of TNT, for instance, per trillion parts of air. That can make it impossible for conventional bomb and mine detectors to detect the explosives and save lives.

They describe development of a preconcentrator that increases the levels of and related explosives by 1,000 times in less than one minute. The scientists made a "molecular sieve" membrane on the surface of holes about as big as a speck of dust. Molecules of explosives get trapped in these holes and concentrated enough that security agents could detect previously undetectable levels of explosives.

Explore further: New star-shaped molecule breakthrough

More information: “Highly Selective Zeolite Membranes as Explosive Preconcentrators”, Anal. Chem., 2012, 84 (15), pp 6303–6307. DOI: 10.1021/ac301359j

Abstract
Highly selective thin zeolite MFI membranes are synthesized on porous stainless steel and α-alumina supports using a seeded growth method. An ultraviolet (UV) light treatment is employed as a low temperature alternative to remove the organic structure-directing agent (SDA) to avoid membrane cracking. The feasibility of the use of the MFI membranes as an explosive preconcentrator is examined by measuring the permeation of nitrogen (N2, an air surrogate) and 1,3,5-trimethylbenzene (TMB) (a 2,4,6-trinitrotoluene (TNT) surrogate) in a mixture of N2 and TMB. High N2/TMB selectivity (>10 000) and reasonable N2 flux (13.5 mmol/m2·s) are observed. On the basis of the flux, a hollow fiber array based preconcentrator is proposed and estimated to provide 1000× concentration within about 1 min using a hollow fiber with a 50 μm internal radius. This high performance explosive preconcentrator may open a new venue for the detection of subppb or lower level of explosives simply in conjunction with conventional explosives detectors.

add to favorites email to friend print save as pdf

Related Stories

Silkmoth inspires novel explosive detector

Jun 01, 2012

Imitating the antennas of the silkmoth, Bombyx mori, to design a system for detecting explosives with unparalleled performance is the feat achieved by a French research team. Made up of a silicon microcantilever ...

New method for detecting explosives

Mar 13, 2009

A group of researchers in Tennessee and Denmark has discovered a way to sensitively detect explosives based on the physical properties of their vapors. Their technology, which is currently being developed into prototype devices ...

Recommended for you

New chip promising for tumor-targeting research

1 hour ago

(Phys.org) —Researchers have developed a chip capable of simulating a tumor's "microenvironment" and plan to use the new system to test the effectiveness of nanoparticles and drugs that target cancer.

New star-shaped molecule breakthrough

7 hours ago

(Phys.org) —Scientists at The University of Manchester have generated a new star-shaped molecule made up of interlocking rings, which is the most complex of its kind ever created.

A refined approach to proteins at low resolution

Sep 19, 2014

Membrane proteins and large protein complexes are notoriously difficult to study with X-ray crystallography, not least because they are often very difficult, if not impossible, to crystallize, but also because ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

mrlewish
not rated yet Aug 08, 2012
Get ready for a million false positives.