Ambient Ionization Mass Spectrometry: Advances in Monitoring Clandestine Activities, Supporting the Warfighter, and Chemical Laboratory Education Redevelopment

Ambient ionization mass spectrometry enables rapid in-situ analysis of a plethora of analytes that are relevant to the forensic and defense communities. As the arsenal of ambient ionization techniques, aimed at solving specific targeted problems, continues to expand, the adoption of these techniques into non-academic settings has been relatively slow. At times, although the technique can provide answers in a more rapid and cheaper manner, the technique does not pass all of the required legal rules for a particular analysis when dealing with forensic evidence. This can be demonstrated with the rapid detection of drugs by paper spray ionization mass spectrometry. Paper spray ionization mass spectrometry can have drugs deposited onto the paper substrate, the paper can wipe a surface for trace analytes, and there are commercial and automated ionization sources for this process. While analysis by paper spray is rapid, the Scientific Working Group for the Analysis of Seized Drugs (SWGDRUG) states that a minimum of two instrumental techniques need to be utilized. Utilizing paper substrates that have nanoparticles embedded for surface enhanced Raman spectroscopy, that can also be utilized for paper spray ionization mass spectrometry, makes ambient ionization more appealing as it completes that first legal requirement. Other times, the slow adoption of these new ambient ionization techniques is due to specific communities not being aware of ambient ionization, and specific applications have not yet been demonstrated. Swab touch spray ionization mass spectrometry follows similar processes as paper spray ionization, as the swab acts both as the sampling substrate and the ionization source and can swab for analytes in a manner where the paper substrate may be damaged and unable to perform the ionization for analysis. This can be seen for the swabbing of organic gunshot residues and explosives, both of which current methods already use a swab for sampling but then need lengthy extraction techniques. The applicability of paper spray ionization and swab touch spray ionization for these forensic and defense analyses is only furthered by the fact that they both couple extremely well with portable mass spectrometers for analysis in the field. There are also many fields that ambient ionization is just starting to take its place in the analytical toolbox. Two such defense fields that are just beginning to expand into ambient ionization are the analysis of pyrotechnics and microelectronics. Pyrolysis gas-chromatography mass spectrometry methods have been developed and utilized for environmental tests for pyrotechnic formulation, but they are slow and there is an abundance of cleaning steps between analyses to prevent carry over and contamination. Using paper and swabs as the collection device and ionization source for environmental analysis of these pyrotechnics allow for them to be functioned at ambient conditions at the scale at which will be utilized in the field by the Warfighter. Similarly, authenticating microelectronics by desorption electrospray ionization mass spectrometry removes the subjectivity of the current methods, while rendering the integrated circuit intact enabling future use if deemed as a genuine part. By taking slower or more subjective tests, in a field that has not utilized ambient ionization heavily in the past and adding these new capabilities to their tool chest expands the acceptance and future applications of the technique. As acceptance and utilization of ambient ionization grows, the next generation of scientists need to have hands on training in these techniques. Through the development of new teaching laboratories that couple both the fundamentals of the technique at hand, while also examining an interesting application to better engage the students, a number of laboratory exercises have been developed. The creation of new laboratory exercise utilizing the next generation of instrumentation and analytical techniques is vital for the future and rapid application of these techniques. The work discussed herein chronicles the utilization and demonstration of ambient ionization mass spectrometry in monitoring clandestine activities, supporting the Warfighter, and redeveloping chemical laboratory education

Molecular Characterization of the Thermal Degradation of Per- and Polyfluoroalkyl Substances in Aqueous Film-Forming Foams via Temperature-Programmed Thermal Desorption–Pyrolysis–Direct Analysis in Real Time–Mass Spectrometry

The release of aqueous film-forming foam (AFFF), containing per- and polyfluoroalkyl substances (PFAS), from Department of Defense activities has received attention over the years due to the environmental persistence and bioaccumulation of PFAS. As a result, the National Defense Act established that the removal of PFAS-containing waste is critical. Thermal destruction methods are commonly used techniques, yet the fate of degraded PFAS remains poorly understood. In this study, we employ thermal desorption–pyrolysis–direct analysis in real time–mass spectrometry (TD-pyro-DART-MS) to characterize products of pyrolysis and determine the extent of degradation from 25 to 600 °C. PFAS ranging from 4–14 carbon atoms were monitored in situ, followed by legacy AFFF. Headgroup scission was observed, followed by carbon–carbon bond cleavages in the structures resulting in [CxFy]− fragments differing by -CF2 (50 Da) and -C2F4 (100 Da). High-molecular weight PFAS resulted in more detectable pyrolytic fragments than low-molecular weight counterparts. AFFF concentrate thermal degradation analysis was more complex and was determined to require higher-resolution mass spectrometers for molecular assignment. This study demonstrates the development of a robust analytical methodology for in situ characterization of the products of thermal degradation of PFAS related to thermal remediation or when PFAS are used to extinguish fuel fires

Novel Selectivity-Based Forensic Toxicological Validation of a Paper Spray Mass Spectrometry Method for the Quantitative Determination of Eight Amphetamines in Whole Blood

Paper spray tandem mass spectrometry is used to identify and quantify eight individual amphetamines in whole blood in 1.3 min. The method has been optimized and fully validated according to forensic toxicology guidelines, for the quantification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxy-N-methylamphetamine (MDMA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA), para-methoxyamphetamine (PMA), para-methoxymethamphetamine (PMMA), and 4-fluoroamphetamine (4-FA). Additionally, a new concept of intrinsic and application-based selectivity is discussed, featuring increased confidence in the power to discriminate the amphetamines from other chemically similar compounds when applying an ambient mass spectrometric method without chromatographic separation. Accuracy was within ±15% and average precision was better than 15%, and better than 20% at the LLOQ. Detection limits between 15 and 50 ng/mL were obtained using only 12 μL of whole blood. [Figure not available: see fulltext.]

Novel selectivity-based forensic toxicological validation of a paper spray mass spectrometry method for the quantitative determination of eight amphetamines in whole blood

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOPaper spray tandem mass spectrometry is used to identify and quantify eight individual amphetamines in whole blood in 1.3 min. The method has been optimized and fully validated according to forensic toxicology guidelines, for the quantification of ampheta281226652676FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2016/01683-

A Low-Cost, Simplified Platform of Interchangeable, Ambient Ionization Sources for Rapid, Forensic Evidence Screening on Portable Mass Spectrometric Instrumentation

Portable mass spectrometers (MS) are becoming more prevalent due to improved instrumentation, commercialization, and the robustness of new ionization methodologies. To increase utility towards diverse field-based applications, there is an inherent need for rugged ionization source platforms that are simple, yet robust towards analytical scenarios that may arise. Ambient ionization methodologies have evolved to target specific real-world problems and fulfill requirements of the analysis at hand. Ambient ionization techniques continue to advance towards higher performance, with specific sources showing variable proficiency depending on application area. To realize the full potential and applicability of ambient ionization methods, a selection of sources may be more prudent, showing a need for a low-cost, flexible ionization source platform. This manuscript describes a centralized system that was developed for portable MS systems that incorporates modular, rapidly-interchangeable ionization sources comprised of low-cost, commercially-available parts. Herein, design considerations are reported for a suite of ambient ionization sources that can be crafted with minimal machining or customization. Representative spectral data is included to demonstrate applicability towards field processing of forensic evidence. While this platform is demonstrated on portable instrumentation, retrofitting to lab-scale MS systems is anticipated

Simultaneous Online Monitoring of Multiple Reactions Using a Miniature Mass Spectrometer

Advances in chemical sampling using miniature mass spectrometer technology are used to monitor slow reactions at a frequency of ca. 180 h^–1 (on the Mini 12) with no sample carryover and with inline derivatization in the case of poorly ionizing compounds. Moreover, we demonstrate high reproducibility with a relative error of less than 10% for major components. Monitoring is enabled using a continuous-flow nanoelectrospray (CF-nESI) probe contained in a custom-built 3D-printed rotary holder. The holder position is automatically set using a stepper motor controlled by a microcontroller. Reaction progress of up to six reactions, including hydrazone formation and Katritzky transamination, can be monitored simultaneously without carryover for several hours