Sponsored by Smiths Detection
By Donald G. Gross, Brandon A. Gayle, Pauline E. Leary and Michael Frunzi
Fentanyl and its analogues are dangerous substances that are not easily identified simply by sight. The ability to accurately and reliably detect and identify these drugs at a scene where their presence is suspected is an important capability to help keep the responder and the community safe.
Ion mobility spectrometry, infrared spectroscopy and Raman spectroscopy are methods that are well suited for this type of analysis. Instruments using these technologies are routinely deployed on scene to support the detection and identification of drugs and other unknown substances. These same methods can be applied successfully to opioids such as fentanyl and its analogues.
Detect invisible particulates with ion mobility spectrometry
Ion mobility spectrometry (IMS) has been used in the field since the 1990s to detect and identify trace amounts of drugs. The benefit of IMS is that it detects particulate residues of narcotics that are invisible to the naked eye.
Although IMS systems have been deployed routinely in other industries, including drug enforcement, to detect drug residues, the use of IMS by the fire service and hazardous response communities is relatively new. This is because the need to detect invisible amounts of drugs has historically not been a concern for these responders.
However, the increasing presence of fentanyl and its analogues at response scenes has created a potentially dangerous environment for both responders and the public at large. In instances where fentanyl or an even more potent analogue like carfentanil is present, the need to detect these substances at low levels can be critically important to the health and safety of the responder. Carfentanil is reported to be approximately 10,000 times more potent than morphine, making airborne particles of this drug extremely dangerous.
How ion mobility spectrometry works
Analysis using IMS to determine the presence of particulate drug residues is performed by swiping an area suspected to contain residues of the drug using a specially designed swab. This swab is then introduced to the IMS system where the narcotic residues are thermally desorbed and ionized using atmospheric pressure chemical ionization. The ion or ions created are then subjected to an electric field, and each ion’s time of flight is measured. The time of flight of the ion or ions is directly related to the drug and is used for identification.
The primary benefits of IMS for drug analysis are its speed and sensitivity. For example, it takes less than 10 seconds to analyze a swab using the Smiths Detection IONSCAN 600, an IMS system designed and programmed to detect fentanyl, its analogues and other narcotics that are invisible to the naked eye.
Analyze samples with infrared spectroscopy
While IMS can be used to detect residues, infrared and Raman systems are also very useful for the analysis of fentanyl and its analogues, whether in powder or liquid form. These tools are not capable of detecting traces that are invisible to the naked eye. They do, however, provide a method of identifying these substances when visible amounts of the drug are present at the scene.
Infrared and Raman spectroscopy are distinctly different from each other and each offers its own advantages. Regardless of which technology is deployed, it is important that the equipment is programmed with the proper libraries so that these substances are detected and identified accurately on scene.
Infrared (IR) systems are commonly used by fire service members for the analysis of drugs and unknown white powders, as well as unidentified liquids.
Infrared systems work by measuring the absorption of the infrared light by the sample. Every drug or chemical will absorb infrared light differently. The IR spectrum generated for each drug, therefore, is unique and can be used to identify the drug.
Infrared analysis is usually able to detect even the smallest differences in chemical structure, so it can be used not only to identify differences in salt forms of drugs (e.g., it can differentiate cocaine HCl from cocaine base), but it can also differentiate fentanyl analogues from each other.
To perform an analysis, a small amount of the sample is placed against the IR system’s sensor and a measurement is collected. Once collected, the IR spectrum is compared against the library of spectra in the system to identify the substance. The advantages of IR are that it is fast, easy, provides the highest level of identification of the drug substance and is non-destructive, meaning that it will not burn or detonate a sample. Collection of an IR spectrum using a tool like the HazMatID Elite from Smiths Detection will take less than one minute.
Analyze samples with Raman spectroscopy
Raman systems, like IR systems, are also commonly used by the fire service for the analysis of powders and liquids. Raman spectrometers work by measuring the scatter, rather than the absorption, of light using a laser light source to collect the measurement.
During an analysis, the powder or liquid sample is placed at the focus point of the laser. As previously noted, different drugs scatter light differently and, just like with infrared technology, the resulting spectrum can be used to identify the drug. Also, just like IR, Raman is usually able to detect even the smallest differences in chemical structure and can differentiate salts, and usually analogues, from each other.
Raman technology is fast, provides the highest level of identification of the substance and can even work through transparent containers such as a clear plastic bag or relatively thin glass jar. Collection of a Raman spectrum using a tool like the ACE-ID from Smith Detection will take approximately 10 seconds.
Although infrared and Raman spectrometry are quite different from, they are sometimes considered to be equivalent. For sure, they are complimentary to each other, i.e., in instances where one method is strong, the other is weak. However, they both have their limitations, which usually determine which is better for the user and a specific application.
Limits of infrared and Raman spectroscopy
Infrared has two primary limitations, especially with regard to the analysis of fentanyl and its analogues. The first is that the user must be exposed to small amounts of the drug in order to perform the analysis. Therefore, it is absolutely critical that the user not only wear the proper level of personal protective clothing and follow other relevant safety procedures, but also that caution is used to prevent any powder samples from becoming airborne at the scene, as airborne particles may be inadvertently ingested.
The second is that IR does not work well when the drug is dissolved in a lot of water. There have been some reports of fentanyl being used in a nasal-spray form. In these instances, it is likely that the fentanyl is dissolved in water for ingestion. In these cases, it is expected that the water in the nasal spray may overwhelm the spectrum, and the spectrum of the water would mask the spectral features of the fentanyl.
For Raman spectroscopy, the primary disadvantage is that many drug substances, including opioids and cutting agents, will fluoresce when exposed to the laser light. Just as water can distort an infrared spectrum, this fluorescence may overwhelm the spectrum and mask the spectral features of the fentanyl.
A second disadvantage of the Raman method, although not necessarily relevant to the analysis of drugs, is that the laser light source required to generate the spectrum can either burn or detonate the sample. Care should be taken, therefore, when using Raman systems, to be sure this is considered prior to analysis of the sample.
Prepare for hidden dangers
Members of the fire service community are used to dealing with hazardous materials using a risk-based response. Fentanyl is only different from other hazardous materials because responders are encountering these highly potent substances without warning on what otherwise appear to be routine calls. For this reason, fentanyl and its analogues may be considered a hidden danger and require a thorough hazard-risk analysis using suitable technologies. With appropriate training and equipment, as well as adherence to accepted procedures, these hidden dangers can be safely and effectively uncovered and mitigated.
About the Authors
Cpt. Donald Gross started his career as a firefighter in 1998, has served as captain of hazmat operations since 2009 and has been providing hazmat training and consulting services, both domestically and internationally, for the past 13 years.
Lt. Brandon Gayle began his fire service career in 1997 and has served as a hazmat specialist since 1999. He is currently a member of the North Carolina Hazardous Materials Regional Response Team 4, as well as the North Carolina Urban Search and Rescue Task Force 8.
Dr. Pauline Leary is a technical solutions engineer for Smiths Detection, where she works with military, emergency response, transportation and critical infrastructure customers to help develop solutions to the problems they are experiencing with detecting, identifying and quantifying dangerous substances and other contraband in the field.
Dr. Michael Frunzi is the senior product manager and subject matter expert for optical technology at Smiths Detection. He specializes in handheld sensor products for CBRNE and narcotics identification applications for military, transportation security and emergency responders.