Boron nitride nanotubes (BNNT), nanobarbs (BNNB), and nanoparticles (BNNP) were used as photocatalysts under 254 nm UV irradiation for the photodegradation of perfluorooctanoic acid (PFOA). Mass spectrometry was used to monitor PFOA degradation via a stepwise mechanism in which CF2 groups were excised from the parent chain. All BNNM were effective catalysts, with BNNB exhibiting the fastest photodegradation rate, and BNNT showing increased activity upon reuse. The enhanced activity of BNNB and BNNT, along with the ability to incorporate these materials into robust structures, makes them promising candidates for use in the fabrication of photocatalytic filters that can remediate aqueous per- and polyfluoroalkyl substances in flow reactors.

Forensic analysis of post-blast and post-burn materials can be critical to a law enforcement or military investigation. 3D-printed cone spray ionization (3D-PCSI) coupled to a field portable mass spectrometer (MS) has been demonstrated as a rapid and low-cost alternative to traditional laboratory-based techniques (high resolution liquid or gas chromatography mass spectrometry) for the detection and analysis of energetic materials. 3D-PCSI-MS can sample trace or bulk energetics within or upon solid matrices with no sample preparation. Solid samples, in this case post-blast or post-burn energetics, are placed within the hollow cavity of the cone that has an approximately 100 µm spray-based emitter at the apex. An extraction/spray solvent is added, and a high voltage is subsequently applied. When coupled to a field portable MS, post-burn and post-blast analyses can be performed in the field. Double base propellant was burned on a variety of substrates and examined via 3D-PCSI-MS. An energetic material and stabilizers used in propellants were detected from the post-burn samples with no sample preparation. Trinitrotoluene (TNT, used in military and commercial explosives) and triacetone triperoxide (TATP, a homemade explosive) were examined post-blast on the US ton scale and the gram scale, respectively.

Motivational hands-on workshops for grade-school level future scientists are needed to inspire young and receptive minds. Described here is an educational event, titled "Inspiring Future Rocket Chemists", with hands-on laboratory exercises demonstrating the fundamentals of rocket flight and live chemistry demonstrations illustrating the fundamentals of rocket propulsion. This event was developed for seventh and eighth grade students by the local Mojave Desert Section of the American Chemical Society and the China Lake Museum Foundation (CLMF). The CLMF is dedicated to educating the public and preserving the history of the Naval Air Warfare Center Weapons Division's contributions to our nation's warfighters. The workshop was developed and led by experts currently working in or retired from the rocket science field. Four hands-on exercises and four demonstrations were performed with the students. The laboratory exercises and demonstrations covered topics including model rocket components and assembly, rocket stability, propulsion, safety, chemical reactions, gas generation, and catalysis in propellants. Two distinguishing characteristics of this event was the inclusion of fundamental principles of rocket science and emphasis on the interdisciplinary nature of the field. The event's pedagogical goals were to motivate and inspire the participants in exploring the field of rocketry while teaching them the fundamental properties and important safety precautions for practicing rocketry. This event serves as the framework for future collaborative efforts between institutions for specialized workshops in topic areas not traditionally covered in student's coursework. The effectiveness of the event was measured through student assessments and feedback at the conclusion of the event.

Smoke dyes are complex molecular systems that have the potential to form many molecular derivatives and fragments when deployed. The chemical analysis of smoke samples is challenging due to the adiabatic temperature of the pyrotechnic combustion and the molecular complexity of the physically dispersed reaction products. Presented here is the characterization of the reaction byproducts of a simulant Mk124 smoke signal on a multigram scale, which contain the dye disperse red 9 (1-(methylamino)anthraquinone), by ambient ionization mass spectrometry. Our previous work has examined the thermal decomposition of a simplified smoke system consisting of disperse red 9, potassium chlorate, and sucrose by anaerobic pyrolysis gas chromatography mass spectrometry performed at the laboratory milligram scale. The results from the lab scale test were compared with a fully functioned Mk124 in the field. To achieve this, Mk124 smokes were functioned in the presence of sampling swabs that collected byproduct residues from the smoke plume in the ambient environment. These swabs were then analyzed using ambient ionization mass spectrometry to identify the expended pyrotechnic residues, with particular interest in halogenated species. Previous work determined the toxicity of unforeseen byproducts identified on the laboratory scale, which were also detected in the field demonstrating the correlation of the laboratory testing to the fielded systems. By understanding the chemical composition of smokes and their reaction products, potential toxicity effects can be easily assessed, leading to safer formulations with improved performance. These results can help assess how smoke byproducts may impact Warfighter performance, personnel health, and the environment.

This study reports a low-cost, open source, and commercial-off-the-shelf automated pipetting robot coupled with a homebuilt desorption electrospray ionization mass spectrometer for the screening of energetic precursor cage compounds.

The systematic screening of acceleration factors across a number of small scale confined volume reactors for the accelerated formation of trioximes. Followed by subsequent scale-up of confined volume reactors utilizing thin film methods.

Rationale The burgeoning concern of N ‐nitrosamine (NAM) contamination found in various pharmaceutical compositions has increased the demand for rapid and reliable screening methods to better assess the breadth of the problem. These carcinogenic compounds are also found in food, water, and soil, and they have been used in poison‐related homicides. Methods A combination of complementary, ambient ionization methods, paper spray ionization (PSI) and filter cone spray ionization (FCSI)‐mass spectrometry (MS), was characterized towards trace‐level residue screening of select NAMs (e.g., N ‐nitrosodimethylamine, N ‐nitrosodiethylamine, N ‐nitrosodibutylamine) directly from complex and problematic matrices of interest, including prescription and over‐the‐counter tablets, drinking water, soil, and consumable goods. Spectral data for analyte confirmation and detection limit studies were collected using a Thermo LCQ Fleet ion trap mass spectrometer. Results PSI‐MS and FCSI‐MS readily produced mass spectral data marked by their simplicity (e.g., predominantly protonated molecular ions observed) and congruence with traditional electrospray ionization mass spectra in under 2 min. per sample. Both methods proved robust to the complex matrices tested, yielding ion signatures for target NAMs, as well as active pharmaceutical ingredients for analyzed tablets, flavorants inherent to food products, etc. Low part‐per‐million detection limits were observed but were shown dependent on sample composition. Conclusions PSI‐MS and FCSI‐MS were successful in detecting trace‐level NAMS in complex liquid‐ and solid‐phase matrices with little to no prior preparation. This work suggests that these methodologies can provide a means for assessing problematic pharmaceutical adulterants/degradants for expedited quality control, as well as enhancing environmental stewardship efforts and forensic investigations.

Trace evidence, including hair, fibers, soil/dust, and gunshot residue (GSR), can be recovered from a crime scene to help identify or associate a suspect with illegal activities via physical, chemical, and biological testing. Vacuum collection is one technique that is employed in recovering such trace evidence but is often done so in a targeted manner, leaving other complementary, chemical-specific information unexamined. Here, we describe a modified 3D-printed cone spray ionization (3D-PCSI) source with integrated vacuum collection for on-site, forensic evidence screening, allowing the processing of targeted physical traces and nontargeted chemical species alike. The reported form factor allows sample collection, onboard extraction, filtration, and spray-based ionization in a singular vessel with minimal handling of evidence by the operator. Utilizing authentic forensic evidence types and portable MS instrumentation, this new method was characterized through systematic studies that replicate CSI applications. Reliability in the form of false positive/negative response rates was determined from a modest, user-blinded data set, and other attributes, such as collection efficacy and detection limit, were examined.

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 degrees 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.

RATIONALE The burgeoning concern of N-nitrosamine (NAM) contamination found in various pharmaceutical compositions has increased the demand for rapid and reliable screening methods to better assess the breadth of the problem. These carcinogenic compounds are also found in food, water, and soil, and they have been used in poison-related homicides. METHODS A combination of complementary, ambient ionization methods, paper spray ionization (PSI) and filter cone spray ionization-mass spectrometry (FCSI-MS), was characterized towards trace-level residue screening of select NAMs (e.g., NDMA, NDEA, NDBA) directly from complex and problematic matrices of interest, including prescription and OTC tablets, drinking water, soil, and consumable goods. Spectral data for analyte confirmation and detection limit studies were collected on a Thermo LCQ Fleet ion trap mass spectrometer. RESULTS PSI-MS and FCSI-MS readily produced mass spectral data marked by its simplicity (e.g., predominantly protonated molecular ions observed) and congruence with traditional ESI-MS spectra in under 2 minutes/sample. Both methods proved robust to the complex matrices tested, yielding ion signatures for target NAMs, as well as active pharmaceutical ingredients (APIs) for analyzed tablets, flavorants inherent to food products, etc. Low part-per-million (ppm) detection limits were observed but were shown dependent on sample composition. CONCLUSIONS PSI-MS and FCSI-MS were successful in detecting trace-level NAMS in complex liquid- and solid-phase matrices with little to no prior preparation. This work suggests that these methodologies can provide a means for assessing problematic pharmaceutical adulterants/degradants for expedited quality control, as well as enhancing environmental stewardship efforts and forensic investigations.

3D-printed cone spray ionization-mass spectrometry (3D-PCSI-MS) is an ambient ionization technique developed for the rapid, in-situ analysis of bulk solids and trace analytes within solid matrices. A reproducibly fabricated 3D-printed cone is used as the collection device, the extraction chamber, and the spray-based ionization source. Herein, we discuss the material selection based on the extraction and spray solvent compatibility with conductive plastic types, the strength of the selected material, and the advantages and disadvantages of the cone geometry. The ease of printing and the required parameters for reproducible manufacturing is also documented. To allow for improved sample throughput, reproducible positioning, and automated solvent delivery and analysis, an autosampler was developed from commercial-off-the-shelf (COTS) parts and custom 3D-printed pieces. Finally, the application of this automated sampling via 3D-PCSI-MS on a field portable mass spectrometer was demonstrated for environmental, defense, and forensic applications.

Several bio-based bisphenols were found to be non-estrogenic through in vitro studies. Polycarbonates derived from these compounds exhibited glass transition temperatures and thermal stability comparable to petroleum-derived thermoplastics.

“Green” pyrotechnics seek to remove known environmental pollutants and health hazards from their formulations. This chemical engineering approach often focuses on maintaining performance effects upon replacement of objectionable ingredients, yet neglects the chemical products formed by the exothermic reaction. In this work, milligram quantities of a lab-scale pyrotechnic red smoke composition were functioned within a thermal probe for product identification by pyrolysis-gas chromatography-mass spectrometry. Thermally decomposed ingredients and new side product derivatives were identified at lower relative abundances to the intact organic dye (as the engineered sublimation product). Side products included chlorination of the organic dye donated by the chlorate oxidizer. Machine learning quantitative structure-activity relationship models computed impacts to health and environmental hazards. High to very high toxicities were predicted for inhalation, mutagenicity, developmental, and endocrine disruption for common military pyrotechnic dyes and their analogous chlorinated side products. These results underscore the need to revise objectives of “green” pyrotechnic engineering.

Confined volume systems, such as microdroplets, Leidenfrost droplets, or thin films, can accelerate chemical reactions. Acceleration occurs due to the evaporation of solvent, the increase in reactant concentration, and the higher surface-to-volume ratios amongst other phenomena. Performing reactions in confined volume systems derived from mass spectrometry ionization sources or Leidenfrost droplets allows for reaction conditions to be changed quickly for rapid screening in a time efficient and cost-saving manner. Compared to solution phase reactions, confined volume systems also reduce waste by screening reaction conditions in smaller volumes prior to scaling. Herein, the condensation of glyoxal with benzylamine (BA) to form hexabenzylhexaazaisowurtzitane (HBIW), an intermediate to the highly desired energetic compound 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), was explored. Five confined volume systems were compared to evaluate which technique was ideal for forming this complex cage structure. Substituted amines were also explored as BA replacements to screen alternative cage structure intermediates and evaluate how these accelerated techniques could apply to novel reactions, discover alternative reagents to form the cage compound, and improve synthetic routes for the preparation of CL-20. Ultimately, reaction acceleration is ideal for predicting the success of novel reactions prior to scaling up and determining if the expected products form, all while saving time and reducing costs. Acceleration factors and conversion ratios for each reaction were assessed by comparing the amount of product formed to the traditional bulk solution phase synthesis.

Chemical warfare agents (CWAs) are toxic chemicals that have been used as disabling or lethal weapons in war, terrorist attacks, and assasinations. The Chemical Weapons Convention (CWC) has prohibited the use, development, production, and stockpiling of CWAs since its initiation in 1997, however, the threat of deployment still looms. Detection of trace CWAs post-deployment or post-remediation, in bulk matrices such as soil, often requires lengthy sample preparation steps or extensive chromatographic separation times. 3D-printed cone spray ionization (3D-PCSI), an ambient ionization mass spectrometric (MS) technique, provides a rapid, simple, and low-cost method for trace CWA analysis in soil matrices for both in-laboratory and in-field detection. Described here is the utilization of conductive 3D-printed cones to perform both rapid sampling and ionization for CWA simulants and hydrolysis products in eight solid matrices. The analysis of trace quantities of CWA simulants and hydrolysis products by 3D-PCSI-MS coupled to both a commercial benchtop system and a field-portable MS system is detailed. Empirical limits of detection (LOD) for CWA simulants on the benchtop MS ranged from 100 ppt to 750 ppb and were highly dependant on solid matrix composition, with the portable system yielding similar spectral data from alike matrices, albeit with lower sensitivity.

A rapid method to empirically determine the presence of trace per- and polyfluoroalkyl substances (PFAS) in solid media, such as soils, sands, and sediments, without any sample preparation, through ambient ionization mass spectrometry (MS), is described. 3D-printed cone spray ionization (3D-PCSI) is an ambient ionization technique that employs a 3D-printed conductive plastic cone to perform both sampling and ionization. The 3D-PCSI sources are fabricated in the shape of a hollowed square pyramid to hold bulk matrices, and consist of rigid walls to aid in the uniformity and consistency of sampling and ionization. Solid samples are placed within the hollowed pyramid and a solvent is added to perform an in-situ extraction, followed by spray-based ionization when a voltage is applied. The low cost of 3D-printing, its reproducibility at scale, and lack of sample preparation, enables 3D-PCSI-MS to rapidly and efficiently screen for trace PFAS, in-situ, in bulk samples. Demonstrated here is the detection of trace PFAS that were doped into six different soil and sediment matrices, by 3D-PCSI-MS, to validate the universality of the method, irrespective of matrix composition. All PFAS were identified by their indicative MS3 spectra and ranged in detection limits from 100 ppt to 10 ppb depending on the compound and soil classification. Legacy aqueous film forming foams (AFFF) were analyzed in soil by 3D-PCSI-MS, as were soil samples collected around an AFFF testing facility. The sampling rate for 3D-PCSI-MS was less than 2 min per sample, demonstrating the applicability to high-throughput mapping of a contaminated area.

Fentanyl and its analogues play a major role in the current opioid epidemic. In particular, these highly potent opioids have become a health hazard due to their use as additives in street drugs. Consequently, rapid on-site procedures for the analysis of this class of seized drugs are needed, especially considering the reported backlog of drug samples, which must undergo identification and confirmation tests to validate the presence of an illicit substance. Paper based devices are cheap sampling and analysis vehicles that have been shown capable of allowing rapid identification and confirmation of drugs of abuse. Modifying paper substrates by imprinting nanoparticles enables surface enhanced Raman spectroscopy (SERS) as well as a second analysis from the same substrate, namely paper spray ionization mass spectrometry. While such a procedure has been described for laboratory use, these illicit drug samples are typically collected in the field and this is where testing should be done. We combine paper SERS and paper spray MS on field-portable and commercial off-the-shelf (COTS) devices for the rapid and low-cost identification and confirmation of fentanyl and its analogues, enabling in situ analysis at the point of seizure of suspect samples. The commercial nature of both instruments moves this technology from the academic realm to a setting where the criminal justice system can realistically utilize it. The capabilities of this single-substrate dual-analyzer technique are further examined by sampling a variety of surfaces of forensic interest.

We present a laboratory experiment, developed around a pair of instrumental analysis techniques, Raman spectroscopy and ambient ionization mass spectrometry (MS), conducted by senior chemistry undergraduate students for bulk analysis of over-the-counter drugs using benchtop versions of the two instruments, as well as trace analysis of illicit drugs utilizing the corresponding portable instruments. The identification and confirmation of seized drugs is a routine operation in forensic laboratories that can be simplified using these two instrumental techniques in tandem. Bulk samples are readily analyzed using conventional Raman spectroscopy followed by paper cone spray ionization (PCSI) MS, while trace analysis is allowed by a simple single-substrate dual-analyzer method using surface enhanced Raman spectroscopy (SERS) from paper followed by paper spray ionization (PSI) MS. The introduction of these novel strategies to the students exposed them to potential career paths in forensic science by means of a hands-on experience that provided fundamental knowledge about this set of analytical methods, including intercomparisons of their performance, as well as practical issues like costs, regulations and databases. The use of portable instrumentation represents an additional learning experience for the students, considering that it is cutting-edge technology that is just now being transferred from academic to industrial labs and that it allows a valuable discussion of the advantages and disadvantages of bringing the laboratory to the field.

Mass spectrometry (MS) techniques are highly prevalent in crime laboratories, particularly those coupled to chromatographic separations like gas chromatography (GC) and liquid chromatography (LC). These methods are considered "gold standard" analytical techniques for forensic analysis and have been extensively validated for producing prosecutorial evidentiary data. However, factors such as growing evidence backlogs and problematic evidence types (e.g., novel psychoactive substance (NPS) classes) have exposed limitations of these stalwart techniques. This critical review serves to delineate the current role of MS methods across the broad sub-disciplines of forensic science, providing insight on how governmental steering committees guide their implementation. Novel, developing techniques that seek to broaden applicability and enhance performance will also be highlighted, from unique modifications to traditional hyphenated MS methods to the newer "ambient" MS techniques that show promise for forensic analysis, but need further validation before incorporation into routine forensic workflows. This review also expounds on how recent improvements to MS instrumental design, scan modes, and data processing could cause a paradigm shift in how the future forensic practitioner collects and processes target evidence.

Process analytical technologies (PATs) are used in the pharmaceutical and other industries to monitor chemical processes in real-time with analytical instrumentation. Each PAT analyzer brings its own advantages and disadvantages to the process, and multiplexing PAT analyzers can be advantageous as they can provide confirmatory measurements and increase the overall confidence of the analysis. In a pedagogical setting, online reaction monitoring enables the instructor to explain the fundamentals of instrumental techniques while highlighting pertinent real world applications. Here we present a teaching laboratory exercise in which students monitor an amide bond formation reaction by flow UV-vis spectroscopy and by mass spectrometric analysis. The coupling of these two specific instruments allows students to investigate two instruments in one laboratory exercise, to explore the fundamentals behind each, and to contemplate the advantages and disadvantages of these instrumental methods. The coupling of the two instruments was aided by 3D printing which allowed students to explore how rapid prototyping can enable the development of innovative procedures.