Mass spectrometry’s important role in identifying explosives

The need for rapid explosive detection is now an unfortunate reality.

The remit is multifaceted. The first is for preventative purposes, to protect us from any threat to life. The second is in the investigative phase, to identify explosives used at a blast site. Then comes environmental monitoring, where explosives have contaminated soil and groundwater.

In the race to identify a broader range of threat materials, what innovations are behind ultra-fast, ultra-sensitive explosive detection methods of the future? Here’s a brief update, with a focus on mass spectrometry’s role in these three fields of analytical science.

1. Analytical innovation that’s protecting us

With every attack on an airport, train station or other public space, the pressure to detect bombs before they’re detonated intensifies. When it comes to chemical detection of explosives, aviation security is leading the way.

Today, ion mobility spectrometry (IMS) is widely used for trace particle detection of explosive residues in airports. While there are faster, more accurate methods in development using ion mobility spectrometry, there are some practical drawbacks. This has led to some security teams relying on dogs, trained to sniff out explosive vapors using theirexceptional sense of smell.

The future? For decades researchers have been trying to develop a chemical detection technology with the tremendous “sniffing” capabilities of dogs. But achieving the required sensitivity has proved unreachable, until now.

The future is an ultra-sensitive, non-contact technology that detects explosive vapors in the air with unparalleled accuracy, in seconds.

Developed by PNNL researchers, the ion chemistry technique was first described in Analytical Chemistry. Recent advancements have resulted in a system that can now detect a more comprehensive range of explosive vapors, deadly chemicals, and illicit drugs simply by sucking air into a metal tube.

The technology behind this uniquely sensitive technique? A mass spectrometer. It’s so precise it can detect 10 molecules of an illicit substance hidden among 1 quadrillion air molecules. That’s like finding 10 human hairs out of all the human hair on the planet. This means that the air can be sampled continuously for explosive molecules as people pass through an area.

While portability, affordability and integration are key hurdles that continuing research will overcome, the technology could be a game-changer. It has the potential to enhance security levels and provide a less intrusive screening environment for transportation hubs, border crossing, stadiums, mail facilities and other security screening applications.

In the meantime, researchers at the MIT Lincoln Laboratory are using mass spectrometry to help develop better training for bomb-sniffing dogs.

2. Analytical innovation in forensic science

Forensic scientists are tasked with the detailed investigation of a blast site to uncover critical clues. The aim is to piece together what occurred and help narrow the search for who created the device or where it might have come from.

This is where liquid chromatography-mass spectrometry (LC-MS) comes in. One of the many technological advances that have been adopted in the forensic science world, it’s widely recognized as the preferred technology for explosive analysis. Used to identify explosive residues in samples collected from a blast site, another relevant application is in fire investigations. It can work out whether an ignitable liquid has been used, and where, to allow for positive identification.

Able to detect individual components with high molecular specificity and detection sensitivity, LC-MS is unparalleled in analyzing trace substances that can be used as evidence. Challenged by the background signal from the sample matrix? Tandem mass spectrometry (LC-MS/MS) can reduce background noise, along with the limits of detection and quantification.

Another challenge in explosive detection (in fact, this applies across many aspects of science), is the “big data” phenomenon. An area of focus is on the ability to take data from a crime scene and use it to help speed up future investigations. This is about digitization and artificial intelligence. More advanced analytical techniques generate vast amounts of data, and this needs to be captured, shared and interrogated. LC-MS systems play an important role in this by creating and storing a robust record of data sets that can be referred to in the future.

3. Analytical innovation for environmental monitoring

Explosives in the environment can pose a significant hazard to humans, wildlife and the ecosystem. They enter the environment during the production process and as a result of detonation, primarily by the military, and mining and construction industries.

Among the greatest potential concerns to the environment? Trinitrotoluene (TNT), Royal Demolition Explosive (hexahydro-1,3,5-trinitro-1,3,5-triazine) (RDX) and High Melting Explosive (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) (HMX) because they are used in the greatest quantities.

Professor Stanislaw Popiel from the Military University of Technology in Poland shares his work with Technology Networks. In his interview, he explores the game-changing role that mass spectrometry is playing in both environmental monitoring and forensic science.

In his own words from the article:

“Mass spectrometry gives us a powerful tool for identification and quantification of explosives, vital in forensic analysis. As well as the explosives themselves, their degradation products can also be detected, which may indicate their use. Tandem mass spectrometry allows us to reduce background signal from the sample matrix and reduce the limit of detection and quantification.”

“Mass spectrometry in combination with gas chromatography and especially liquid chromatography can be used in a very wide research spectrum related to explosives. In comparison to other techniques, mass spectrometry is advantageous because with one detector we can do both qualitative and quantitative analysis of explosives and their degradation products. Also, mass spectrometry, especially high-resolution mass spectrometry, enables us to monitor the degradation and metabolization path of explosives, and identify unknown compounds.”

I couldn’t have put it better myself!

It’s fair to say that mass spectrometry is driving innovation in a field of science that needs to stay several steps ahead. Join our forensics community to keep up with curated content on news, trends, methods and information kits.

(Technology Networks article quoted from: https://www.technologynetworks.com/analysis/articles/mass-spectrometrys-important-role-in-identifying-explosives-in-the-environment-313831)