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Scenarios involving hazardous materials (HAZMAT) present a significant number of challenges to the responding community. Often, little information is known about the mission at hand. Threats can change rapidly, making tactical decision-making more difficult. With emphasis on the protection of responders, the public, and the surrounding environment, information about the identity of the chemical material(s) on a HAZMAT scene is critical.
Responders rely on a suite of chemical detection and identification tools to perform their tasks. While no tool is perfect, each has a purpose that is tied to an actionable result, like the selection of personal protective equipment (PPE), response tactics, and impact to the surrounding environment. Not all responders have access to the same suite of tools, but a baseline working knowledge of all classes of chemical detection equipment is highly desirable. Additionally, each tool has its place in the mission and can be used in tandem with other techniques.
Portable and cost-effective colorimetric tools and lower explosive limit (LEL) meters help detect the presence of a class of chemical threats. Portable spectroscopic tools like Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and ion mobility spectrometers (IMS) presumptively identify chemical threats, but with limited selectivity (the ability to distinguish and identify one chemical from another). This limits the ultimate impact of the information from these devices. Ideally, response teams will implement a well-established chemical identification technique such as GC/MS to provide lab-quality analytical performance and chemical confirmation at the site of interest.
GC/MS instruments are inherent to the laboratory environment and have long been considered the “gold standard” for chemical identification. Often, when a field sample (e.g., forensic investigation, suspected clandestine lab, etc.) is collected for analysis by an accredited lab, a GC/MS is involved. The inherent selectivity gained by directly probing the “fingerprint” of a chemical through mass spectrometry leads to true confirmatory identification and the substantial reduction of chemical misidentification.
While no HAZMAT scenario or response mission is the same, two unique situations are presented below in which a person-portable GC/MS can be used to provide confirmatory chemical identification. The FLIR Griffin G510 portable GC/MS (FLIR Systems, West Lafayette, IN) was used to produce the analytical data presented in this article and is shown in Figure 1.
Figure 1 – FLIR Griffin G510 portable GC/MS analyzing a chemical spill in Vapor Survey mode.Railcar derailment and breech of known hazard
In a derailment scenario, chemicals can leak from a damaged DOT-111 tank car, posing a threat to responders, but also creating a risk of contaminating the surrounding environment. While limited information presented to responding personnel is a common thread among HAZMAT incidents, some scenarios provide more information than others. Tank cars are typically marked with an external label, and the train’s manifest links this car to the same material. Initial responders arriving on-scene must quickly assess and mitigate hazards.
In this scenario, a person-portable GC/MS can play a critical role in quickly confirming the identity of a leaking tank car, but also in the assessment of the extent of contamination. After a leak has been stopped, the surrounding environment must be assessed. A person-portable GC/MS can be used to perform confirmatory chemical identification in the vapor phase followed by subsequent analysis of environmental samples for threat hazard mitigation and cleanup efforts.
Upon deployment at the scene, the Griffin G510 can be operated in Air Confirm mode to detect the presence of vapors near a breeched railcar, thus confirming the identity of the chemical threat. Secondarily, sampling tools such as solid-phase microextraction (SPME) can be used to determine the extent of the migration of the material, especially in aqueous (water-based) environments. For example, if the spill hazard zone is located near a ditch, creek, or other body of water, SPME sampling can result in the detection of trace amounts of the product without arduous sample preparation.
Even well after the incident has been resolved, the Griffin G510 can continue to be used in a remediation role for subsequent analysis of environmental samples for contaminated material. Long-term data collection campaigns may involve semiroutine analyses of samples from a response vehicle or mobile laboratory.
A common chemical carried in tank cars is ethylbenzene, often used in the production of plastics and other synthetic materials. Figure 2 is a full GC/MS result and NIST confirmation of the presence of ethylbenzene detected using Air Confirm mode. Figure 3 is an alternative alarm view that simplifies and expediates data review in the field.
Figure 2 – Chromatogram and mass spectrum with NIST confirmation of the presence of ethylbenzene.
Figure 3 – Alternative color-coded simple alarm view identifying ethylbenzene to expedite response.Motor vehicle accident involving unknown material in plastic drum
There are situations in which minimal information is available to the responding community. These missions have the potential to be more chaotic in nature, as response tactics and decision-making must take place in the absence of critical information. Consider a scenario in which a commercial vehicle, like a semitrailer transporting several unlabeled plastic drums, is involved in a motor vehicle incident. During the collision, one of the drums is damaged and leaks a moderate quantity of an unknown, white crystalline material. After securing the scene, responders review the motor carrier’s manifest and the material is not listed.
Although this narrative presents a simplistic view of a scenario, additional information is needed before response tactics and other decisions can be made. GC/MS can be used as a tool to gain the information needed for data-driven decision-making in a hazardous environment. The portable nature of the Griffin G510 represents a strong implementation of this technology.
In this situation, responders wearing appropriate PPE can use the handheld tools at their disposal (FTIR, Raman, IMS, colorimetric, etc.) to understand the basic threat nature of the material. Additionally, the Griffin G510 GC/MS can be operated in Vapor Survey mode by responders wearing full vapor encapsulated PPE for the detection of high-consequence threats.
Figure 4 – Syringe injection being performed on the FLIR Griffin G510 portable GC/MS.In the instance that no vapor threats are found in an initial investigation, the responder can obtain a small sample of the material and return it to a warm zone. Here, an additional responder can perform routine sample workup, in which the material is dissolved in a small amount of a solvent, rendering an organic liquid solution. Figure 4 shows the resulting solution being directly injected into the Griffin G510’s built-in liquid sample injector for separation by capillary GC and detection by mass spectrometry.
Figure 5 shows data obtained from the Griffin G510 identifying an unknown material as parathion, an organophosphate-based pesticide and known carcinogen that is severely restricted for use in the United States. In a single sample, the system also detected and confirmed the presence of octane, a common straight-chain hydrocarbon. The identification of these materials helps responders choose appropriate PPE and better understand the nature of the hazard for subsequent cleanup efforts. Additionally, the high-fidelity data obtained from in-field GC/MS may be of use in subsequent legal proceedings against the motor carrier, shipper, and receiver.
Figure 5 – Data result identifying parathion and octane in a single sample analysis via FLIR Griffin G510.Conclusion
GC/MS has long played a critical role in traditional laboratory-based chemical analysis and is the gold standard for analysis. But chemical emergencies rarely occur in the safety of a laboratory. Chemical emergencies can happen anywhere, extending the need for GC/MS equipment beyond the lab. Person-portable GC/MS systems, like the FLIR Griffin G510, provide the ability to confirm the presence and identity of unknown threats directly on-scene, increasing the safety of first responders, the community, and the environment.
Philip Tackett, Ph.D., is certified HAZMAT responder and GC/MS product manager at FLIR Systems, Inc., 3000 Kent Ave., West Lafayette, IN 47906, U.S.A.; tel.: 765-775-1701; e-mail:[email protected]; www.flir.com