How Mass Spectrometry and Ambient Ionization Techniques Are Improving Drug Detection in Forensics

Since the 2009 National Academies report on strengthening forensic science, the National Institute of Standards and Technology (NIST) has prioritized advancing forensic chemistry research. Part of that effort takes place within the Material Measurement Science Division (MMSD), which is one area of the forensic science research effort at NIST. MMSD focuses on seized drugs, ignitable liquids, gunshot residue, and trace evidence, working closely with practitioners, industry, and other NIST scientists to address pressing analytical challenges and implement practical solutions (1). Equipped with both standard and emerging technologies such as gas chromatography–mass spectrometry (GC–MS), Fourier transform infrared (FT-IR) spectroscopy, and direct analysis in real time mass spectrometry (DART-MS), MMSD develops new methods, spectral libraries, workflows, and visualization tools that enhance safety, speed, and objectivity in forensic casework (1). Research efforts span improving seized drug analysis amid evolving drug landscapes, applying rapid screening to fire debris and gunshot residues, and advancing inorganic trace evidence analysis, including modern glass standards and elemental characterization of 3D-printed ghost guns (1).

As part of “From Sample to Verdict,” LCGC International sat down with Ed Sisco and Sarah Shuda, Research Chemists at NIST, to discuss the work that their groups are conducting that are helping to advance forensic analysis.

How is your team using mass spectrometry (MS)—particularly ambient ionization techniques—to improve the speed and reliability of illicit drug detection in forensic and public health settings?

We have included ambient ionization mass spectrometry (AI-MS) in our research and programmatic efforts for more than a decade. These efforts began with developing approaches for forensic drug chemists to obtain high-quality, rapid data for presumptive drug analysis. Building on these efforts, we now use AI-MS in our Rapid Drug Analysis and Research (RaDAR) program, which provides near real-time drug checking to public health and public safety entities across the country. The use of non-chromatographic MS enables us to complete a full qualitative analysis of a sample in under a minute, which allows us to provide critical information on the drug landscape to partner agencies in under 48 hours.

To ensure the reliability of the data we and others are generating, our research efforts span everything from method development and validation to the creation of AI-MS-specific algorithms and libraries, as well as end-user training. More recently, we have begun conducting interlaboratory studies for the analysis of street drugs using AI-MS to understand the current state of practice and to inform future standardization efforts.

Are you able to respond rapidly to changes in the types of illicit drugs (designer drugs) that are made for the street?

Yes, we are able to respond to rapid changes in the drug supply. Internal spectral databases are kept up to date by making frequent additions as new reference materials become available. Once new reference materials are analyzed, data collected prior to the addition of the compound can be datamined to identify prior samples containing that compound.

When designer drugs first emerge, reference materials are not always available right away. In these instances, we leverage commercially available and in-house tools to allow us to classify or identify an unknown. We also collect data from multiple platforms (AI-MS, gas chromatography mass spectrometry [GC-MS], and liquid chromatography ion mobility mass spectrometry [LC-IM-MS]) to assist in structural elucidation.

What are some of the key measurement challenges in tracking and identifying emerging synthetic opioids, and how is your research helping stakeholders respond more effectively to the opioid epidemic?

There are multiple measurement challenges associated with identifying emerging synthetic opioids. First, the landscape is everchanging. We saw it with fentanyl analogs in the 2010s, as well as the introduction of utopioids shortly after, and are now seeing it continue with the emergence of new nitazenes. These compounds are introduced to the drug supply, often before reference materials are available, making it challenging to identify them because they are not in spectral databases. To make identification more challenging, synthetic opioids are typically potent, meaning their concentration in street drugs is low. This requires sensitive methods of detection, but with increased sensitivity comes the risk of reporting background signals as positive identifications for a compound. This makes understanding the limitations associated with instrumentation and reporting critical. We help end users address these challenges by investigating new instrumental techniques, developing suitable methods, and providing validation information to the community.

It isn’t just laboratories facing challenges. Public safety and public health personnel in field settings require reliable portable devices. We have recently begun method optimization and validation efforts on several portable devices, including ambient ionization mass spectrometers, which are not yet routinely used in the field, to address some of the limitations of field testing like difficulties identifying components in mixtures and a lack of sensitivity.

One of your goals is to lower the barriers to implementing new technologies in drug analysis. What are the main obstacles forensic labs face, and how are you working to overcome them?

When forensic laboratories implement any new technology, or even a new method on existing technology, they have to conduct a validation to show the method or instrument is fit-for-purpose in that it can identify or quantitate compounds of interest accurately and reproducibly. Although there are documents from standards bodies instructing laboratories that they must perform validations and listing general validation parameters to assess, there are often no specific instructions on how to perform these experiments or which parameters apply to what kinds of validation in forensic drug analysis. Designing validations that are rigorous and will produce data representative of how a method or an instrument will perform in a casework situation is time consuming. We are creating validation and implementation packages that can be used by laboratories to implement technology and methods more easily. These packages include method parameters, standard operating procedures, and excel templates to house validation data. This will ensure that validations are suitable and standardized.

Related to the investigation of new technologies, laboratories working on method development and validations need access to real-world samples to demonstrate usability on street samples. These types of samples can be difficult for universities, researchers, and industry partners to obtain. To address this challenge, we now offer panels of well-characterized authentic samples as research-grade test materials for use in technology assessments and method validations. This enables laboratories to analyze authentic materials that have been independently identified using multiple methods outside their own laboratory.

Finally, training is a barrier to implementation of new technology. Training provided by vendors or available through webinars or workshops is not typically discipline specific and usually address topics like general instrument operation and maintenance and software overviews. Training focused specifically on the analysis of drugs and how to properly interpret data is harder to come by. We routinely provide workshops at forensic science and analytical chemistry conferences that cover mass spectral interpretation and different tools that are available to help practitioners evaluate their data.

How does your work at the intersection of forensic science, public safety, and homeland security influence the development of real-world tools and protocols for frontline responders?

Our research program is unique in that we’re able to bring together a wide range of end-users (public health, law enforcement, and forensic science), researchers, and industry partners to enable and inform the development of fit-for-purpose technologies. Through collaborations, workshops, and trainings we’re able to intimately understand the measurement challenges for each end-user community and work to understand the solutions they need and the operational limitations that may be present. We can then convey this information to industry partners and work with them on modifications to hardware or software, assist them in constructing spectral databases, and conduct foundation validations. This foundational data can then be used by end-users to determine whether a particular technology is suitable for their application. We also work to connect industry to end-users through technology demonstrations both in the laboratory and in the field.

How is the MMSD advancing the detection of trace particles and thin films on surfaces, and what impact could these developments have on contraband screening and forensic investigations?

The MMSD has had a long history of looking at how to best collect trace residues off surfaces. This began in the trace explosives detection space in the post-9/11 era and has since expanded to include street drugs, pharmaceuticals, and other residues of interest. We continue to advance this work in different ways, often using mass spectrometry as a tool within the scope of a larger ecosystem. For instance, we use laser-based visualization tools to better understand the movement of particles in the construction of an improvised explosive device or during the synthesis of illicit drugs to understand where to sample in order have the highest probability of detection. We also use precision deposition inkjet printing – similar to your printer at home except our inks are solutions of explosives or drugs – to be able to generate trace residues with highly controlled masses. This allows us to produce materials that can be used by industry partners to better understand the performance of their detection technology or enable us to create mock samples with known amounts of contamination.

In what ways is your group working to standardize sampling and instrument performance, and why is this standardization critical for safety, security, and forensic applications?

A key focus of our group is to develop approaches to minimize the barrier for adoption of new methods or technologies in forensic laboratories. A major effort in this space is the development of Validation and Implementation packages, which provide laboratories with the necessary documents and guidance to get new technology up and running in their laboratories. Through these efforts, we assume the burden of comprehensive method development and foundational validation, enabling the laboratories to only have to conduct a simplified validation, which we provide the outline and data processing tools for. By providing these types of packages, we can work to standardize analytical methods, or at the very least validation of the methods, across the community. We compliment these efforts with trainings, interlaboratory studies, and spectral libraries as resources to further standardization.

Standardization of methods, and reporting practices, is becoming increasingly critical as the drug landscape continues to change. Being able to standardize data generated across laboratory systems will unlock the ability to do things we currently cannot do or do them in a more streamlined fashion. For instance, use of a standard GC–MS method, along with retention time locking or retention indices, would enable laboratories to easily share information on new compounds in the drug supply, even if a reference material isn’t available for comparison. It would also allow for simplified datamining, enabling people to retrospectively look at chromatographic data to determine when a new compound was first encountered. Standardized methods and reporting would also ensure that if the same sample was analyzed in two different laboratories, the same result would be obtained.

In terms of technology, what are the current limitations of mass spectrometry instrumentation?

In the areas we are currently working in, the main challenges we face are often more about the software and interacting with the data than the instrumentation itself. For instance, many of the non-targeted analysis platforms are designed for -omics based analyses and don’t always easily translate into the world of small molecules. Newer systems, especially those using ion mobility, generate datasets that are difficult to work with manually. As a lab that uses instrumentation from multiple vendors, proprietary software formats present additional challenges when we want to batch or merge datasets. This is further complicated by the fact that not all vendors export to the same open-source format. On the fieldable instrument side, software is often designed so the instruments can be used by non-technical personnel, which makes interacting with the raw data or building in-house spectral databases difficult.

From an instrument side, a limitation we face every day with non-chromatographic mass spectrometry techniques is the inability to differentiate positional isomers and some isobaric compounds. Depending on the intended use of the data, this limitation can be overcome by reporting the undifferentiated compound (for example, reporting fluorofentanyl instead of para-fluorofentanyl). In other instances, like drug tracing or forensic drug analysis, this information is critical and requires the sample be analyzed on additional techniques.

In terms of fieldable, non-chromatographic mass spectrometry systems, we have seen difficulties in accurately detecting all components in complex street drug mixtures. For street drugs, the compound of most concern can often be present at lowest concentration, due to its high potency, but detection can be hindered by lack of sensitivity, competitive ionization, or poor sample collection. On the chromatographic side there is a need to increase chromatographic speed while maintaining separation of critical pairs.

References

1. NIST, Edward Sisco (Fed). NIST.gov. Available at: https://www.nist.gov/people/edward-sisco (accessed 2025-07-24).
2. NIST, Materials Measurement Science Division. NIST.gov. Available at: https://www.nist.gov/mml/mmsd (accessed 2025-08-18).