Chemical Detection, FLIR Systems, Inc.

FLIR Griffin G510.

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 on-scene confirmation and identification of unknown threats, increasing the safety of first responders, the community, and the environment.

A CLOSER LOOK: CHEMICAL RESPONSE TOOLS

Responders rely on a suite of chemical detection and identification tools to perform their tasks. Each tool has a purpose which is tied to an actionable result – 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 working knowledge of all classes of chemical detection equipment is important. Each tool has its place in the mission and can be used in tandem with other techniques.

FLIR Griffin G510.

States of Matter:

Chemical hazards can be in the liquid, solid, or vapor state. Determining the state of matter is a critical, early step in on-scene response and the selection of chemical detection equipment. A variety of tools can be used to sample and detect or identify each phase of matter:

Sensitivity and Selectivity:

Chemical detectors vary in sensitivity (the ability to detect very low levels of chemicals) and specificity (the ability to distinguish and identify targets).

  • Colorimetric test kits are used for fast presumptive information about a chemical. They are single-use, inexpensive tests used to determine the presence of a threat, as well as its chemical class.
  • A multi-gas monitor is a critical personal safety device used to detect toxic gas leaks, including carbon monoxide and chlorine. Some monitors are equipped with photoionization detectors for volatile organic chemical (VOC) detection. Gas monitors are sensitive, but susceptible to interferents.
  • Spectroscopic tools (Raman and FTIR) are primarily used for bulk samples and can quickly interrogate unknown solids and some liquids. This equipment is lightweight and fast, but not ideal for trace-level detection.
  • IMS is a fast, sensitive, and presumptive identification technology that should be verified by confirmatory technology. IMS systems provide critical early warning to the presence of a chemical threat but are prone to frequent false positive readings in field situations due to sample overloading and environmental effects.
  • High pressure mass spectrometry (HPMS) is an emerging technology that has similar benefits and drawbacks to IMS but enables larger libraries with lower false alarms and greater data processing.
  • Gas Chromatograph-Mass Spectrometry (GC-MS) is the “gold-standard” technology used to analyze complex samples, including liquid, vapor, and solid-phase chemicals. Although the most expensive class of technology, the GC-MS is selective and sensitive and offers the broadest capability – making it the ultimate confirmatory tool. Results can be produced in seconds or minutes, depending on the mission and sample type.

Confirmatory Tools:

Ideally, response teams will implement a well-established chemical identification technique like GC/MS for on-site, lab-quality analytical performance and chemical confirmation. GC/MS instruments are inherent to the laboratory environment. The inherent selectivity gained by directly probing the “fingerprint” of a chemical through mass spectrometry leads to true confirmatory identification and decreases chemical misidentification.

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 on-scene confirmation and identification of unknown threats, increasing the safety of first responders, the community, and the environment.

by Philip Tackett, Product Manager