Detecting Nitro-Explosives

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There are a variety of explosives which are differentiated based on their explosive charge. Explosive charge refers to a measured quantity of explosive material. This article begins with the kinds of nitro-explosives such as trinitrotoluene (TNT), dinitrotoluene (DNT) and trinitrophenol (TNP), which are very closely related explosive compounds. Except for these, there are PETN, HMX, RDX: Extremely powerful explosives which can be used pure or in plastic explosives.

Nitroglycerin or Nitro-Explosive was the first practical explosive produced that was considered to be stronger than black powder. It was initially synthesized by the Italian Chemist Ascanio Sobrero in 1847 who strongly warned people against employing it as an explosive. Later, it was adopted as a commercially useful explosive by Alfred Nobel.

However, detection, lax check and security measures on such explosives have resulted in a lot of incidences, one of which is as follows:

Auburn, California, April 21^st, 1866. On Monday, in San Francisco, an explosion occurred in the storeroom back of Wells, Fargo & Co.'s building, adjoining California Street, which destroyed everything within a circuit of 40 or 50 feet.

In today's time, selective and rapid detection of explosives has become one of the most demanding issues concerning homeland security. Tons of explosives are detected in a number of unexploded landmines all over the world.

The detection of explosives and their associated compounds for security screening, detection of unexploded ordnance, demining and pollution monitoring is an active area of research. An extensive range of detection methods and an even broader range of physical chemistry issues are involved in this extremely challenging area.

Thus, California-based ELECTRONIC SENSOR TECHNOLOGY Inc. presents…..zNose^®!

An Electronic Nose for Ultra-Fast Gas Chromatography

zNose^® is considered to be the perfect vapor force-protection tool as it is able to speciate. It also quantifies the chemistry of any vapor with picogram sensitivity and its universal solid-state detector is not ionic and does not need a radioactive ionization element.

zNose^®, because of its universality, is capable of detecting and identifying virtually any vapor threat including those from bioterrorism, explosives and bio-chemical threats over the range C6 to C30.

Retention time libraries allow the use of simple alkane calibration standards instead of explosive standards or hazardous chemicals.

zNose^® produced completely speciated chromatograms of TNT, DNT and TNP using a 5 mL sample of headspace vapors. zNose^® demonstrated picogram sensitivity to volatile organics above C16 and the minimum detection limit was almost 1 picogram. Higher sensitivity well into the part per trillion range could effortlessly be achieved by increasing the sample time to 60 seconds (30 mL air sample).

Tons of explosives are detected in many unexploded land mines all over the world. Nitro-aromatics such as 2,4-dinitrotoluene (2,4-DNT), 2,4,6-trinitrotoluene (TNT), and 2,4,6-trinitrophenol (TNP) are common ingredients of industrial explosives which have contaminated groundwater and soil at large. Thus, the detection of nitro-aromatics present in groundwater and soil is extremely crucial for environmental monitoring near ordnance bases. Trinitrophenol (TNP or picric acid), Trinitrotoluene (TNT) and Dinitrotoluene (DNT) are all closely related chemical compounds with varied volatility and vapor pressures, which can be explored by direct injection using zNose^® and headspace analysis.

This information has been sourced, reviewed and adapted from materials provided by Electronic Sensor Technology.

For more information on this source, please visit Electronic Sensor Technology.