The Vital Role of Spectroscopy in Modern Emergency Response

Portable spectroscopy technology plays an incredibly important role in emergency response. From testing an unknown compound at a crime scene, to detecting airborne carcinogens during a structural fire, these tools are both vital in helping to solve crimes and protect the lives of first responders. Yet, most first responders have very little, if any, formal training in forensic and analytical chemistry.

Brandon Gayle is the president of Gayle Training Solutions.

Brandon Gayle, president of Gayle Training Solutions, has been training emergency first responders on how to use tools like portable Raman and Fourier transform infrared (FT-IR) spectrometers in the field since 2006. He provides training and consulting services for instrument manufacturers and distributors, and has worked with first responders in the military, the police force, firefighters, and more.

Spectroscopy spoke with Gayle about his work with emergency responders and how portable spectroscopy technology is playing a more vital role in the field.

You’ve trained a variety of first responders, from emergency medical services to the marines. What are some best practices that you utilize when teaching non-experts how to use analytical equipment to get the most accurate results?

It is my teaching philosophy that there needs to be a balance between teaching the "how" and the "why" of chemical sampling. Most responders will say they just want to know what button to press to get the results they are looking for, but in reality, to get those results, they need to understand some of the theory, or the "why,” behind the technology so that they are able to obtain good data. I view my responsibility, as a trainer, as being a translator between the analytical experts and the boots on the ground. I try to teach just enough chemistry and physics to give an operator the best opportunity to obtain good data, data that can then be analyzed by a chemist and relayed back as actionable intel, but not so much that I lose the student. I teach them how to recognize what a good background looks like and how to know when they have background interference. I also teach what makes for a good spectrum in FT-IR and Raman and how to improve the spectrum through the sampling technique. If an operator can obtain good quality data with a good background, then even if the device algorithm is not able to produce high confidence results, a Reachback (service support) scientist most likely can interpret the data for them.

What are some best practices that you share with first responders for bulk sample preparation in the field?

I teach a sampling methodology where the responder carries a sample from basic benchtop wet chemistry and use of air monitoring sensors to more technical instrumentation like ion mobility spectrometry (IMS) or flame spectrometry and then up to FT-IR and Raman and, if available, high pressure mass spectrometry (HPMS) or gas chromatography-mass spectrometry (GC–MS). The idea is to carry a prediction from one level to the next, always looking back to confirm results with previous results, so that when a low confidence result is obtained, decisions can be easily made about the sampling process, and any need to alter that process to produce more confident results. I tell students to use a methodology that moves from simple to complex. This assures that there is always safety considerations made for both the responder and the instrumentation throughout the process. Determinations on sampling technique for more advanced technology can be made based on early findings with their indicating papers and sensor responses. An example is using water test paper or M8 Chemical Detection Paper to determine if the sample is an aqueous solution or contains water contamination. This will drive whether to select FT-IR or Raman as the next technique as well as what type of sample preparation is necessary to safely run the sample on GC–MS.

What considerations do first responders have to make when completing an accurate analysis in a high-pressure situation?

I always tell responders to seek out three "proofs" for any reported result, whether that is three separate technologies producing the same or similar results or confirming results with colorimetric tests, sensor response, and physical characteristics found through research. For example, if I have an unknown, clear liquid that has a pH of 7, no KI paper (potassium iodide starch oxidizer test paper) response, it readily soaks into M8 (indicating a hydrocarbon), has a vapor response on a PID (photoionization detector), indicating possible low ionization potential and high vapor pressure, and a high confidence result on FT-IR for a hydrocarbon, I feel confident reporting that result as a light hydrocarbon because I have confirming results across multiple technologies. Using a proven sampling methodology based on the available technologies assists in avoiding misidentifications and hasty decisions on an emergency scene.

Firefighters working with ambulance in the background. © Soph- stock.adobe.com

What advantages do portable FT-IR and Raman spectroscopy technologies offer first responders?

The advantages are that advancements in our field have produced small, lightweight, decon-able (decontaminable) devices that have vast libraries and advanced mixture algorithms that produce actionable results in real-time. We are no longer dependent on collecting samples to send to a lab and having to wait hours to days for results that we need to make on-scene decisions on time-sensitive actions like exposure treatment, evacuation distances, PPE (personal protective equipment) selection, and decontamination process. Handheld Raman devices have allowed us to be able to identify substances through thin-walled containers without having to handle the substance and handheld FT-IR devices have allowed for the identification of samples in all three phases of matter with small amounts of sample. Both technologies are non-destructive, allowing for sample conservation in evidentiary sampling and they are very complementary. For instance, FT-IR struggles with peroxides, but Raman "sees" peroxides very well. Conversely, Raman struggles with identifying nitrates where FT-IR "sees" nitrates very well. There are low absorbers for FT-IR and fluorescence challenges for Raman that make it necessary to have both handheld technologies available.

What are some potential analytical challenges portable FT-IR and Raman spectroscopy tools present and how can analysts address them?

Obviously, continued advancement and innovation in the field of handheld and portable technology is needed. We still face challenges when it comes to dealing with complicated mixtures and low concentration components of illicit drugs. Though manufacturers have done a great job of keeping their libraries updated with emerging threats, many handheld techniques have an LOI (limit of Identification) that is well above the encountered concentrations of minor components that we deal with in the field.

Also, with the advancements in the field of artificial intelligence (AI) and machine learning (ML), I can envision the integration of results from multiple complimentary and overlapping technologies built into one device to yield a higher confidence analysis of field samples. An orthogonal design approach to handheld devices is not a new concept, but one that faced many limitations and challenges before the advent of AI. I feel that we, as an industry, are much closer to solving many of those challenges by using AI and ML.

Another, more immediate, area of needed improvement is in the Reachback services offered. The level of Reachback service varies from company to company. Some companies make their top scientists available within minutes on a 24/7 basis, yet others offer more of a "24 hour" response window for their services. When responders are making real-time, life or death decisions, we need a more immediate response from customer support. Most emergency responders, even hazardous materials experts, are not chemists, so having unlimited access to a forensic chemist can be invaluable.

What new or emerging areas where portable FT-IR and Raman spectrometers are being used in forensic analysis? What do you expect to see in the future of forensic analysis using spectroscopy tools?

The latest advancement in handheld FT-IR is undoubtably the XplorIR from 908 Devices. It is a handheld FT-IR gas/vapor identifier that uses continuous monitoring to identify nearly 5600 gases in real-time with quantification. It can identify mixtures of up to six components in air with very high confidence scores and continuously quantify all six components simultaneously. This has proven to be a huge gap filler in current air monitoring technology, exponentially improving responder safety. The previous challenge with FT-IR gas identification was always dealing with water vapor and carbon dioxide in the atmosphere and how to account for that in a constantly changing environment. The XplorIR employs an Adaptive Atmospheric Correction algorithm that continuously accounts for water vapor and CO2 in the atmosphere and looks past it to identify other contaminants that may be present. These advancements have culminated to produce a very powerful handheld tool that, I predict, will be deployed by every hazardous materials response team in the country within the next couple of years.

Looking to the future, I can envision the combination of existing technologies to provide detection and identification of airborne contaminates that are known carcinogens, with the intent of improving the safety of firefighters working on emergency scenes. Structure fires involve very complicated chemical reactions from the combustion of countless synthetics that produce numerous byproducts. These byproducts are proven to produce both acute and chronic health effects to those who risk their lives daily to make ours better. If we could develop detection and identification techniques that could quantify the long-term threat to responders, I feel that many lives could be extended, thereby allowing our responders to enjoy their long-deserved retirements with a far lower risk of contracting cancer.

Is there anything else that you think our readership would want to know about your work?

Advancements in chemistry continue to improve the quality of daily life for many people, however, there is a cost. For every advancement, there is an unintended consequence.

For example, EVs (electric vehicles) may be helping to reduce our dependence on fossil fuels and reduce our carbon footprint, but when these advancements outpace our infrastructure and our ability to quantify the adverse health and environmental effects, people get hurt in the interim. Firefighters tend to take the brunt of these ill effects because we are the ones called out to deal with situations where technology has failed or gone awry. The fascinating chemistry behind battery technology can become deadly when it fails. And who is called to deal with the situation when it does? Firefighters.

We need continued and equal advancements in the field of detection and identification of potential threats while dealing with emergencies that arise from chemistry gone awry. I am personally very thankful to the dozens of scientists that I have had the pleasure of meeting and working with over my career who devote their careers to designing and creating affordable solutions to many of the problems that we responders face daily.