A maconha é a droga ilícita mais consumida no mundo, tem como substância psicoativa o delta-9-tetraidrocanabinol (9-THC). Os testes colorimétricos são normalmente realizados em amostras de maconha (e para qualquer outra droga ilícita) apreendidas. A adição de reagentes específicos em uma solução de extrato de maconha pode indicar a presença de substância ilícita mediante mudança de cor. No entanto, a literatura recentemente tem relatado ocorrências de resultados falso-positivos quando os testes colorimétricos são aplicados em algumas folhagens de diversas espécies de plantas. Este estudo utilizou as técnicas voltamétricas em meio orgânico N-N-dimetilformamida utilizando tetrafluoroborato de tetrabutilamônio como eletrólito de suporte e eletrodos de trabalho de disco de carbono vítreo e platina. Aplicando-se um potencial de pré concentração em - 0,5 V, verifica-se um pico de corrente anódica em ± 0,01 V vs Ag/AgCl ,KCl(sat). Utilizando eletrodo de disco de carbono vítreo como eletrodo de trabalho, na modalidade de onda quadrada, obteve-se uma dependência linear na faixa de concentração entre 1,0 x 10-9 mol L-1 a 2,2 x 10-8 mol L-1, com um coeficiente de correlação linear em 0,999 e um limite de detecção de 6,2 x 10-10 mol L-1. Tais resultados possibilitaram a determinação de 9-THC na ordem de nmol L-1. / Marijuana, the illicit drug that is most consumed worldwide, contains 9-tetrahydrocannabinol (9-THC) as the main psychoactive substance. Presumptive colorimetric tests are usually performed on seized marijuana (or any illicit drug) samples: the addition of specific reagents to the marijuana extract solution prompts a change in. This study was developed using voltammetric techniques in organic medium (N,N-dimethylformamide) using tetrabutylammonium tetrafluoroborate (TBATFB) as supporting electrolyte, and glassy carbon and platinum disc as working electrode. Applying a pre-concentration potential of -0.5 by square-wave voltammetry, we detected a well-defined anodic peak current in ± 0.01 V versus Ag/AgCl, KCl(sat); 9-THC detection presented linear dependence at concentrations ranging from 1.0 × 10-9 mol L-1 to 2.2 × 10-8 mol L-1, with a linear correlation coefficient 0.999 and a detection limit of 6.2 × 10-10 mol L-1, using the glassy carbon disc working electrode.

A 3,4-metilenodioximetanfetamina (MDMA) é a principal substância psicoativa comercializada ilegalmente em comprimidos de ecstasy. O MDMA é uma droga de ação psicotrópica e uso proscrito, conforme lista F (grupo F2) da ANVISA, pois apresenta propriedades alucinógenas e estimulantes e seu uso/abuso pode gerar uma série de danos à saúde dos usuários. O desenvolvimento de eletrodos quimicamente modificados (EQMs) na eletroanalítica tem por finalidade a obtenção de sistemas de detecção mais sensíveis e seletivos para o analito de interesse. Também, considera-se necessário desenvolver novas técnicas e métodos para a detecção de compostos em amostras de interesse forense, a fim de obter ferramentas para auxiliar os cientistas forenses no combate ao comércio ilícito de substâncias. Conforme problemática exposta, este trabalho teve por finalidade o desenvolvimento de eletrodos quimicamente modificados utilizando como modificadores da superfície eletródica de carbono vítreo o Nafion e Nafion/CB[7], utilizando deposição por drop coating e spin coating para a detecção de MDMA através das técnicas de voltametria cíclica e onda quadrada. Conforme o sistema empregado, os melhores EQMs desenvolvidos foram de Nafion (1,5% v/v) e Nafion (1,5% v/v)/CB[7] (10,0 µg.mL-1). Os EQMs desenvolvidos apresentaram limite de detecção e quantificação na faixa de traços e menores que aqueles reportados em outros trabalhos da literatura. Considerando a aplicação dos EQMs para a detecção de MDMA em amostras de ecstasy, verificaram-se as respostas voltamétricas de outras substâncias: cafeína, metanfetamina, teobromina, lidocaína, cloridrato de procaína, (±)-metanfetamina e cloridrato de cocaína. Nas condições experimentais empregadas, observou-se que as substâncias estudadas não atuam como falsos positivos para o MDMA. Paralelamente, obtiveram-se onze lotes de comprimidos de ecstasy (apreendidos e cedidos pela Polícia técnico-científica de Ribeirão Preto-SP) e realizaram-se análises qualitativas e quantitativas nos mesmos, utilizando técnicas colorimétricas (Marquis, Ácido sulfúrico, Simon e Simon com acetona) e cromatográficas (CG-EM E CLAE-EM). Considerando o melhor EQM desenvolvido, quantificaram-se 11 lotes de ecstasy pela técnica voltamétrica e cromatográfica, dentre os lotes estudados, dois não continham MDMA, um apresentou uma mistura de MDMA e cafeína e os demais continham MDMA. A concentração de MDMA presente nos lotes variou de 0 até 61 % em massa. A detecção de MDMA em ecstasy pelo método voltamétrico desenvolvido se mostrou viável e sensível para o analito de interesse. / The 3,4-methylenedioxymethamphetamine (MDMA) is the main psychoactive component of ecstasy tablets, that have an illicit trade. MDMA has been an illicit psychotropic drug, and it has a prohibited use (group F2, in ANVISAs F list), because of its hallucinogenic and stimulating effects, and the use/abuse can poses serials health risks. The development of chemically modified electrodes (CME) in electroanalytical methods aims to get more sensitive and selective systems to detect the analytes. In this context, it is necessary to develop new techniques and methodologies to the detection of illicit samples; it provides more tools to help the forensic scientists to combat the illicit drug trade. So, this work focused in the development of chemically modified electrodes (CMEs) with modifications on the glassy carbon surface by drop coating and spin coating using Nafion and Nafion/CB[7] solutions. The CMEs were tested using cyclic, and square wave voltammetry to detect MDMA. Considering the employed system, the best CMEs were made by Nafion (1.5% v/v), and Nafion (1.5% v/v)/CB[7] (10.0 µg.mL-1) thin films. It was possible to observe better sensitivities for these sensors, in comparison to other MDMA studies reported in the literature. The specificity of the proposed sensors was checked in relation to other drugs: caffeine, methamphetamine, theobromine, lidocaine, procaine hydrochloride, and cocaine hydrochloride. These drugs do not interfere in this voltammetric method. Additionally, we studied eleven lots of ecstasy samples, allowed by the Scientific Police - Ribeirão Preto-SP, and we provide qualitative and quantitative studies using colorimetric techniques (Marquis, Sulfuric acid, Simon, and Simon with acetone), and chromatografic techniques (GC-MS and HPLC-MS). The MDMA quantification in real samples was obtained by high performance liquid chromatography with a mass spectrophotometer, and we compared with the voltammetric technique, using the developed CME. Between the analyzed lots, two of them didnt present in their composition, one lot had a mix of caffeine and MDMA, and another presented MDMA. The MDMAs concentration in lots had a large variation, with 0 to 61 % w/w. The MDMAs voltammetric detection in ecstasy lots was viable. And, it is also possible to apply this methodology to analyze MDMA traces.

The Forensic Chemistry Laboratory of Johannesburg (FCL JHB) is tasked with the chemical analysis of a variety of samples to assist in determining the cause of death where unnatural cause is suspected. Some of the samples submitted to the laboratory have a herbal or muti connotation, but a large portion of these cases turn out to have no herbal components present as only pharmaceutical or agricultural products are detected in these samples. This study combined, for the first time, forensic investigation, chemistry and botany to create a unique platform needed for the identification of poisonous plants and their components in forensic exhibits and viscera. The research was focussed on the poisonous plants previously detected at the laboratory, as well as the requests received for the analysis of muti/toxic plant components. The selection of plants included Nicotiana glauca, Datura stramonium / Datura ferox, Callilepis laureola, Boophone disticha / Ammocharis coranica, Abrus precatorius, Ricinus communis, Nerium oleander / Thevetia peruviana and Bowiea volubilis. All these species are known to have caused fatalities, hence their choice. Nicotiana glauca has been implicated in the deaths of at least 15 people since 2001. It was previously detected by GC-MS (EI) in plant exhibits, but could not be detected in a viscera matrix. A selective extraction method for alkaloids was used to extract botanical and viscera samples. Anabasine was successfully detected on the HPLC-MS (EI) system but this detection technique was not considered sensitive enough. A very sensitive HPLC-MS method was developed on the ZMD detector by using electrospray technology. This method outperformed both electron impact detectors (GC and HPLC) and could detect 1ng/ml anabasine with relative ease in full scan mode. Datura stramonium and D. ferox have not been previously positively linked to any human poisoning or death due to exposure to botanically derived products at the FCL JHB. Atropine and scopolamine were successfully ionised in ESI positive mode and could be detected at 10 pg/ml and 100 pg/ml level respectively. The identities of the compounds were confirmed by characteristic ISCID fragmentation patterns. The developed method was successfully applied to a suspected heart attack case. The results proved conclusively that the deceased was given D. ferox seeds as part of his meal and an overdose of atropine and scopolamine contributed to his death. Callilepis laureola is reputed to be one of the more commonly used medicinal plants in South Africa, and although its use has been indicated by the specific mention of a possible nephrotoxin and/or hepatotoxin as causative agent, it has not been detected in any of the forensic chemistry laboratories in South Africa. This was mainly due to the absence of a reliable method for the analysis of the main toxic component of C. laureola, atractyloside, by mass spectrometry. A sensitive and very selective HPLC-ESI-MS method was developed that could detect atractyloside, carboxyatractyloside and their monodesulfated analogues in botanical and viscera matrices. The method was successfully applied to a variety of forensic samples and proved that C. laureola may play an important role in herbal poisonings. In a selection of suspected herbal poisonings where the cause of poisoning was unknown, 30% of the samples tested positive for the presence of atractyloside, carboxyatractyloside or their monodesulfated analogues. The bulbs of Boophone disticha are rich in isoquinoline alkaloids and some of the alkaloids were detected by GC-EI-MS and LC-EI-MS, but the detection of these alkaloids in viscera samples was not successful. A routine method used for the screening for drugs of abuse in forensic samples, were successfully used for the analysis of the bulb extracts of B. disticha and the bulb scales of A. coranica. The chromatographic profile of these two plants appeared very similar at a first glance, but a closer evaluation of the mass spectra highlighted significant differences between the two plants. Six alkaloids from B. disticha were isolated and characterised by LC-MS and NMR and these compounds were detected in suspected herbal poisoning cases. It has been shown that B. disticha is one of the commonly used plants to “clean the system” but frequently results in the death of the patient. Abrus precatorius contains one of the most toxic compounds known to mankind, namely abrin that collectively refers to a group of glycoproteins. The seeds of A. precatorius also contain two indole alkaloids, abrine and hypaphorine. The two alkaloids were fractionated and characterised by LC-MS and NMR. Due to the fact that the instrumentation of the FCL JHB is not suited to the detection of proteins, an LC-ESI-MS method was developed for the detection of the two alkaloids in plant and viscera matrix as markers for A. precatorius. The presence of these two alkaloids was indicated on the TMD system (EI spectra) in a suspected herbal poisoning case. The LC-ESI-MS method was applied to the analysis of the samples and the absence of abrine and hypaphorine were proven in the samples. Ricinus communis is similar to A. precatorius in that it also contains a group of extremely poisonous glycoproteins, collectively refered to as ricin. The analysis of R. communis seeds encountered the same problems as the analysis of A. precatorius seeds, and the analysis was again focused on the detection of the minor piperidine alkaloid ricinine. The LC-ESI-MS method developed for abrine was modified to detect ricinine and functioned well in botanical and viscera matrices. This method will enable the forensic analyst to detect ricinine in very low levels when the presence of ricinoleic acid in samples indicates the use of a R. communis-based product. Nerium oleander is a common decorative garden plant that is used medicinally. The plant is rich in cardenolides with oleandrin the main compound. A reversed-phase chromatographic method with ESI mass spectral detection was developed to separate and detect 11 cardiac glycosides. The compounds were adequately separated to allow unambiguous identification, and displayed very stable cationisation with sodium. An extraction method was developed to extract the cardiac glycosides from the leaves of N. oleander and Thevetia peruviana and was also evaluated in a viscera matrix. The extraction method functioned well and extracted a variety of compounds that produced unique chromatographic fingerprints, allowing for the easy differentiation between the two plants. The method is ideally suited for the detection of oleandrin in high concentrations (full scan mode), low concentrations (selected masses) or trace levels (SIM analysis of ion clusters). The method is able to distinguish between extracts derived from N. oleander and T. peruviana and was able to detect and confirm neriifolin, odoroside and neritaloside in N. oleander leaf extracts. Analysis of forensic case exhibits were also successfully done with this method and performed well with liquid and solid matrices. With the new method oleandrin could be detected at trace levels in viscera samples that did not produce positive results in the past. Bowiea volubilis is widely used as a medicinal plant, but is also an extremely toxic plant. It is freely available at traditional healer markets, and is one of the most highly traded plants on the Durban market. Despite the high usage of the plant, it has not been detected by any of the forensic laboratories in South Africa. Bovoside A, a bufadienolide, is reported to be the main cardiac glycoside in the bulb of B. volubilis. The cardiac glycoside method was successfully applied to the analysis of the bulb extract of B. volubilis and bovoside A was identified as the main bufadienolide present in the bulb. Bovoside A was fractionated and characterised by LC-MS. Four extracts of botanical origin could be successfully distinguished from each other by monitoring the main masses of bovoside A, oleandrin and thevetin A and thevetin B. These marker compounds were well separated from each other and made the identification of the botanical extracts quite easy, and the identity of each extract was confirmed by the mass spectrum of each peak. / Prof. F.R van Heerden

<p>Solid Phase Microextraction (SPME) is a popular sampling technique that can be paired with Gas Chromatography/Mass Spectrometry (GC-MS). SPME-GC-MS is used in forensic chemistry due to its simplification of the sample preparation process. Headspace-Solid Phase Microextraction (HS-SPME) is a technique where the sample is heated to generate volatiles in the headspace of the vial. A SPME fiber is then inserted into the vial and the compounds in the headspace will bind to the fiber. Total Vaporization- Solid Phase Microextraction (TV-SPME) is a technique that is derived from the HS-SPME technique. </p><p>In Chapter 1, the critical comparison of HS-SPME and TV-SPME is discussed. Samples including marijuana, essential oils, and CBD oil were utilized to compare the two techniques. The compounds of interest in marijuana are the three main cannabinoids: cannabinol (CBN), cannabidiol (CBD), and tetrahydrocannabinol (THC). The sample preparation and GC-MS parameters were kept the same for all samples to determine which SPME technique works best for these sample types and yielded the greatest sensitivity. It was found that HS-SPME shows greater sensitivity with CBN and equivalent sensitivity with essential oils, THC and CBD. </p><p>In Chapter 2, the detection of synthetic cannabinoids utilizing liquid-liquid injection as well as HS-SPME and TV-SPME is discussed. The detection of these compounds is important because this type of drug has become more prevalent in the United States because they can be chemically altered slightly so they still have the effects of a drug but can evade drug legislation. The detection of synthetic cannabinoids using liquid injection was found to be successful but detection using HS-SPME and TV-SPME was found to be unsuccessful. </p>In Chapter 3, the analyses of real and artificial saliva utilizing HS-SPME and TV-SPME is discussed. Determining the compounds present in real saliva and artificial saliva will be of importance for future research into determining if the presence of drugs in saliva can be analyzed with these techniques. The analyses of real and artificial saliva were found to be successful using HS-SPME, without derivatization, and TV-SPME, with and without derivatization. Many of the compounds present in the real saliva were detected and were confirmed to be compounds regularly found in saliva by other scientific literature.

Indiana University-Purdue University Indianapolis (IUPUI) / Paper spray mass spectrometry (PS-MS) is an ambient ionization technique that has been proven useful in many types of investigative analyses. However, the use of this technique with regards to environmental samples has been largely unexplored since the technique’s development. In this work, paper spray mass spectrometry was utilized to detect and quantify compounds for environmental, forensic and chemical defense applications. Due to the sensitive nature of some projects, the work was split into two volumes. Volume 1 focuses on the detection of pharmaceuticals in soil using paper spray (Chapter 2) and the detection of chemical warfare agent (CWA) simulants and CWA hydrolysis products (Chapter 3). Volume 2 focuses on the detection and quantitation of fentanyl analogs in environmental matrices. Chapter 5 focuses on the rapid analysis of fentanyl analogs in soil matrices. The following chapter evaluates the ability of PS-MS to detect low concentrations of fentanyl analogs in water (Chapter 6). Throughout this work, paper spray has proven to be an effective, rapid alternative to chromatography for the analysis of environmental samples.

Indiana University-Purdue University Indianapolis (IUPUI) / In forensic chemistry, a quicker and more accurate analysis of a sample is always being pursued. Speedy analyses allow the analyst to provide quick turn-around times and potentially decrease back-logs that are known to be a problem in the field. Accurate analyses are paramount with the futures and lives of the accused potentially on the line. One of the most common methods of analysis in forensic chemistry laboratories is gas chromatography, chosen for the relative speed and efficiency afforded by this method. Two major routes were attempted to further improve on gas chromatography applications in forensic chemistry. The first route was to decrease separation times for analysis of ignitable liquid residues by using micro-bore wall coated open-tubular columns. Micro-bore columns are much shorter and have higher separation efficiencies than the standard columns used in forensic chemistry, allowing for faster analysis times while maintaining the expected peak separation. Typical separation times for fire debris samples are between thirty minutes and one hour, the micro-bore columns were able to achieve equivalent performance in three minutes. The reduction in analysis time was demonstrated by analysis of ignitable liquid residues from simulated fire debris exemplars. The second route looked at a relatively new detector for gas chromatography known as a vacuum ultraviolet (VUV) spectrophotometer. The VUV detector uses traditional UV and far-ultraviolet light to probe the pi and sigma bonds of the gas phase analytes as well as Rydberg traditions to produce spectra that are nearly unique to a compound. Thus far, the only spectra that were not discernable were from enantiomers, otherwise even diastereomers have been differentiated. The specificity attained with the VUV detector has achieved differentiation of compounds that mass spectrometry, the most common detection method for chromatography in forensic chemistry labs, has difficulty distinguishing. This specificity has been demonstrated herein by analyzing various classes of drugs of abuse and applicability to “real world” samples has been demonstrated by analysis of de-identified seized samples.

<p>Analysis of explosives (intact and post-blast) is of interest to the forensic science community to qualitatively identify the explosive(s) in an improvised explosive device (IED). This requires high sensitivity, selectivity, and specificity. Forensic science laboratories typically utilize visual/microscopic exams, spectroscopic analysis (e.g., Fourier Transform Infrared Spectroscopy (FTIR)) and gas chromatography/mass spectrometry (GC/MS) for explosive analysis/identification. However, GC/MS has limitations for explosive analysis due to difficulty differentiating between structural isomers (e.g., 2,4-dinitrotoluene, 2,5-dinitrotoluene and 2,6-dinitrotoluene) and thermally labile compounds (e.g., ethylene glycol dinitrate (EGDN), nitroglycerine (NG) and pentaerythritol tetranitrate (PETN)) due to mass spectra with very similar fragmentation patterns. </p><p>The development of a benchtop vacuum ultraviolet spectrometer coupled to a gas chromatography (GC/VUV) was developed in 2014 with a wavelength region of 120 nm to 430 nm. GC/VUV can overcome limitations in differentiating explosive compounds that produces similar mass spectra. This work encompasses analysis of explosive compounds via GC/VUV to establish the sensitivity, selectivity, and specificity for the potential application for forensic explosive analysis. Nitrate ester and nitramine explosive compounds thermally decompose in the VUV flow cell resulting in higher specificity due to fine structure in the VUV spectra. These fine structures originate as vibronic and Rydberg transitions in the small decomposition compounds (nitric oxide, carbon monoxide, formaldehyde, water, and oxygen) and were analyzed computationally. The thermal decomposition process was further investigated for the determination of decomposition temperatures for the nitrate ester and nitramine compounds which range between 244 ºC and 277 ºC. Nitrated compounds were extensively investigated to understand the absorption characteristics of the nitro functional group in the VUV region. The nitro absorption maximum appeared over a wide range (170 - 270 nm) with the wavelength and intensity being highly dependent upon the structure of the rest of the molecule. Finally, the GC/VUV system was optimized for post-blast debris analysis. Parameters optimized include the final temperature of a ramped multimode inlet program (200 ºC), GC carrier gas flow rate (1.9 mL/min), and VUV make-up gas pressure (0.00 psi). The transfer line/flow cell temperature was determined not to be statistically significant.</p><br>

<p dir="ltr">Scientists across many disciplines have observed a striking phenomenon: chemical reactions that do not appreciably occur in large volumes often proceed readily in microdroplets. At the core of suggested mechanisms is the influence of interfacial chemistry on the overall reaction; when the interfacial area dominates the reactor volume, the measured reaction rate is often accelerated. For instance, microdroplets with a high surface area-to-volume ratio (generally with radii smaller than 10 µm) provide a unique reaction environment and have been observed to accelerate a wide variety of chemical reactions. This is likely surprising to most readers, as much of our chemical intuition comes from experiments performed on benchtops in beakers (large, single-phase systems). However, microdroplets are regularly exploited by nature, from multiphase atmospheric aerosols to biomolecular condensates in cells. Thus, it is vital to have measurement tools capable of studying multiphase, nanoscale reactors. An electrochemical perspective on measuring multiphase chemistry under nanoconfinement is given in Chapters 2-4. To my knowledge, there were no reports of accelerated reactivity in microdroplets from electrochemical studies until the 2021 observation that enzyme turnover rates are inversely-related to the size of the containing nanodroplet (given in Chapter 6). In this dissertation work, we developed new electroanalytical tools to probe chemical transformations/reactions at micro- and nano-interfaces and made use of new reaction schemes that capitalize on multiphase microenvironments.</p><p dir="ltr">Much of the method development was built on the foundation of stochastic nanoelectrochemistry, a technique that is reviewed thoroughly in Chapters 2, 4, and 5. Briefly, stochastic nanoelectrochemistry is the measurement of single nano-entities, one-at-a-time, as the collide with a micron-sized electrode. The nano-entities studied in this dissertation were aqueous droplets, either suspended in an immiscible oil continuous phase or propelled through air. We dove deeply into these studies, from using correlated microscopy to watch how these micro- and nanodroplets collide with other interfaces to building simulations to quantify changes to the chemistry inside. We showed how the surface environment directs water nanodroplet collisions (Chapter 10) and measured the sub-diffraction-limited nanometer contact area that forms between a microdroplet and a metal surface (Chapter 11). Using the nanodroplets as tiny reactors, we measured accelerated rate constants and promoted unfavorable nucleation events in attoliter-femtoliter aqueous droplets (see Chapter 6-7 and Chapter 12, respectively) and in microliter aqueous droplets (see Chapter 8 and Chapter 9, respectively).</p><p dir="ltr">As mentioned above, microdroplets are ubiquitous in air (<i>e.g.,</i> aerosols). However, electrochemistry is not an obvious choice for the measurement of intact aerosols because electrochemistry is traditionally performed in a conductive solution, and electrochemistry in air is difficult. In this dissertation we laid the groundwork for a path forward that allows electrochemical access the air|microdroplet interface. We designed and characterized a novel electrochemical cell, where the working electrode is a microwire traversing a suspended liquid film (Chapters 13-15). The early results were born from pure curiosity: Can we do electrochemistry in a soap bubble wall? Chapter 13 shows that the answer is “Yes!”, and that electrochemistry can report on aerosol contents that are collected from the air into this thin film. However, the soap bubble wall was severely limited by the lifetime of the bubble wall (bubbles pop), so in Chapters 14 and 15, we introduce a suspended ionic liquid film that does not pop from evaporation. With the more robust system, we realized the ability to probe intact single microdroplets, one-at-a-time (Chapter 14), giving electrochemical access to the air|water interface.</p><p dir="ltr">As detection of illicit substances from aerosols has the potential for immediate impact on first responder, user, and bystander safety, we employed the new technology to electroanalyze aerosolized methamphetamine (Chapter 13) and fentanyl (Chapter 15). Electrochemistry is small, simple, and affordable, making it a realistic candidate for an in-field sensor. We overcame selectivity challenges by using our understanding of interfacial microenvironments to leverage local pH changes, as demonstrated by the reliable detection of low purity cocaine in mixed powders (Chapter 16). This patented method provides a highly selective technique for cocaine identification in the presence of adulterants without the need to bring any chemicals to the scene (water is our only reagent!).</p><p dir="ltr">In sum, this body of work contributes to the electrochemical studies in nano- and microdroplets, extending the reach to account for droplet size on measured rates and to include microdroplets with a water|air boundary. Applications of the work were focused on in-field detection of illicit substances.</p>

Gunshot residue (GSR) analysis is a crucial aspect of the investigation of firearms-related incidents. The presence of GSR on a person or surface can provide valuable insight regarding proximity or involvement of an individual in a shooting incident. Traditionally, GSR analysis relies on the detection of inorganic compounds within the ammunition, known as inorganic gunshot residue (IGSR). These inorganic compounds are comprised of lead, barium, and antimony. IGSR compounds originate from the content of the primer, and each individual element is expelled during discharge, fused while molten, and land on nearby surfaces. Stubs with an adhesive coat are used to collect these particles by pressing against a surface suspected to have GSR particles. The current analytical method for detection and identification of IGSR, Scanning Electron Microscopy and Energy Dispersive X-Ray Spectroscopy (SEM/EDS), surveys GSR stubs for both the elemental composition as well as the morphology of the compounds. Positive identification requires both the elemental composition and spherical morphology of IGSR. Several issues exist with the nature of IGSR as well as the current method of analysis. Identification by SEM/EDS not only requires time for transportation and labor but may also produce false negatives due to inconsistent shape or lack of all three elements. The development of a rapid and robust analytical technique would address these deficiencies. Mass spectrometry (MS) is a standard analytical technique known for its specificity and accuracy. New advancements in research and technology have produced the ability to miniaturize MS while retaining its superior capabilities in identification. The characteristics of IGSR also pose issues in terms of validity, such as specificity to discharging a weapon, and ability to be transferred or wiped off. Qualities such as these can lead to both false negatives and false positives. In recent years, advances in forensic science research have studied the composition of organic gunshot residue (OGSR) as well as new methods for detecting these compounds. Research has pointed towards advantages in OGSR that would rectify the analytical issues seen in using IGSR as the target compound. Some qualities of OGSR that would improve GSR detection are its specificity to GSR, the molecular complexity of its components, its higher persistence on surfaces, and lower transferability. This study addressed both issues by employing the MX908 High Pressure Mass Spectrometer and developing an analytical method for major OGSR targets. The objective of this research was to test the MX908’s ability to ionize and detect Nitroglycerin (NG), Diphenylamine (DPA), Ethyl Centralite (EC), Dibutyl Phthalate (DBP), and Nitroguanidine (NQ). Furthermore, these experiments tested a range of voltage parameters to achieve optimal fragmentation, and ultimately an accurate and specific analytical method.

<p>Ambient ionization mass spectrometry enables rapid <i>in-situ</i> 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. </p> <p>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.</p> <p>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.</p> <p>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. </p>