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In this study we demonstrate the potential of selective reagent ionisation-time of flight-mass spectrometry for the rapid and selective identification of a popular new psychoactive substance blend called ‘synthacaine’, a mixture that is supposed to imitate the sensory and intoxicating effects of cocaine. Reactions with H3O+ result in protonated parent molecules which can be tentatively assigned to benzocaine and methiopropamine. However, by comparing the product ion branching ratios obtained at two reduced electric field values (90 and 170 Td) for two reagent ions (H3O+ and NO+) to those of the pure chemicals, we show that identification is possible with a much higher level of confidence then when relying solely on the m/z of protonated parent molecules. A rapid and highly selective analytical identification of the constituents of a recreational drug is particularly crucial to medical personnel for the prompt medical treatment of overdoses, toxic effects or allergic reactions.

This thesis focuses on the detection of threat agents, i.e. explosives and new psychoactive substances (NPS) using SRI-ToF-MS (Selective Reagent Ionisation-Time of Flight-Mass Spectrometry). This is a novel technology, able to detect trace gas compounds with high sensitivity, high selectivity and virtually in real time. While its ability to detect volatile organic compounds (VOCs) in a wide range of fields has already been demonstrated, there has only been a small amount of research into homeland security applications. The interest in the field of homeland security has been raised by the increased risk of terrorist activities in recent years. Drug use also poses significant challenges to society. A study from the United Nations Office of Drugs and Crime (UNODC) has identified the increase in the number and rate at which New Psychoactive Substances (NPS) are legally entering the market as one of the most notable trends in drug markets over the last 5 years. These substances represent an obvious risk, as their effects on health are mostly unknown. The present thesis involves a detailed study on 10 NPS using SRI-ToF-MS. No previous investigations of NPS involving this analytical technique had been carried out. Hence, for each of these substances (mostly recreational stimulants) both, mass spectra at standard operational conditions and complete E/N studies (i.e. dependence of the product ion branching ratios on the ratio between the electric field, E, and the gas number density, N) are recorded. Furthermore, the product ion branching ratios at selected E/N values are used to identify the composition of an unknown mixture, i.e. a commercial NPS blend of unknown composition legally available online under the branded name “synthacaine”. One of the major limitations of classic Proton Transfer Reaction-Mass Spectrometry (PTR-MS) is the ambiguousness in compound identification, as it relies solely on m/z values (i.e. the mass-to-charge ratio) of the product ions. Therefore co, This thesis focuses on the detection of threat agents, i.e. explosives and new psychoactive substances (NPS) using SRI-ToF-MS (Selective Reagent Ionisation-Time of Flight-Mass Spectrometry). This is a novel technology, able to detect trace gas compounds with high sensitivity, high selectivity and virtually in real time. While its ability to detect volatile organic compounds (VOCs) in a wide range of fields has already been demonstrated, there has only been a small amount of research into homeland security applications. The interest in the field of homeland security has been raised by the increased risk of terrorist activities in recent years. Drug use also poses significant challenges to society. A study from the United Nations Office of Drugs and Crime (UNODC) has identified the increase in the number and rate at which New Psychoactive Substances (NPS) are legally entering the market as one of the most notable trends in drug markets over the last 5 years. These substances represent an obvious risk, as their effects on health are mostly unknown. The present thesis involves a detailed study on 10 NPS using SRI-ToF-MS. No previous investigations of NPS involving this analytical technique had been carried out. Hence, for each of these substances (mostly recreational stimulants) both, mass spectra at standard operational conditions and complete E/N studies (i.e. dependence of the product ion branching ratios on the ratio between the electric field, E, and the gas number density, N) are recorded. Furthermore, the product ion branching ratios at selected E/N values are used to identify the composition of an unknown mixture, i.e. a commercial NPS blend of unknown composition legally available online under the branded name “synthacaine”. One of the major limitations of classic Proton Transfer, by Matteo Lanza, Enth. u.a. 5 Veröff. d. Verf. aus den Jahren 2013 - 2014, Innsbruck, Univ., Diss., 2015

The isomers 4-methylethcathinone and N-ethylbuphedrone are substitutes for the recently banned drug mephedrone. We find that with conventional proton transfer reaction mass spectrometry (PTR-MS), it is not possible to distinguish between these two isomers, because essentially for both substances, only the protonated molecules are observed at a mass-to-charge ratio of 192 (C12 H18 NO(+) ). However, when utilising an advanced PTR-MS instrument that allows us to switch the reagent ions (selective reagent ionisation) from H3 O(+) (which is commonly used in PTR-MS) to NO(+) , O2 (+) and Kr(+) , characteristic product (fragment) ions are detected: C4 H10 N(+) (72 Da) for 4-methylethcathinone and C5 H12 N(+) (86 Da) for N-ethylbuphedrone; thus, selective reagent ionisation MS proves to be a powerful tool for fast detection and identification of these compounds.

One of the most common volatile organic compounds (VOCs) group is monoterpenes. Monoterpenes share the molecular formula C10H16, they are usually cyclic and have a pleasant smell. The most common monoterpenes are limonene (present in citrus fruits) and α-pinene (present in conifers’ resin). Different monoterpenes have different chemical, biological and ecological properties thus it is experimentally very important to be able to differentiate between them in real time. Real time instruments such as Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS), offer a real time solution for monoterpene measurement but at the cost of selectivity resulting in all monoterpenes being seen at the same m/z. In this work we used Selective Reagent Ion-Time of Flight-Mass Spectrometry (SRI/PTR-ToF-MS) in order to explore the differences in ion branching when different ionizations (H3O+, NO+ and O2+) and different drift tube reduced field energies (E/N) were used. We report a comprehensive ion library with many unique features, characteristic for individual monoterpenes.

Proton Transfer Reaction Mass Spectrometry (PTR-MS) is a well-established technique for real-time VOCs (Volatile Organic Compounds) analysis. Although, it is extremely sensitive (with sensitivities of up to 4500 cps/ppbv, limits of the detection < 1 pptv and the response times of approximately 100 ms) the selectivity of PTR-MS is still somewhat limited, as isomers cannot be separated. Recently, selectivity-enhancing measures, such as manipulation of drift tube parameters (reduced electric field strength) and using primary ions other than H3O+, such as NO+ and O2+ have been introduced. However, monoterpenes, which belong to the most important plant VOCs, still cannot be distinguished so that more traditional technologies, such as gas chromatography mass spectrometry (GC-MS), have to be utilized. GC-MS is very time consuming (up to 1 h) and cannot be used for real-time analysis. Here we introduce a sensitive, near real-time method for plant monoterpene research: PTR-MS coupled with fastGC. We successfully separated and identified six of the most abundant monoterpenes in plant studies (α- and β-pinenes, limonene, 3-carene, camphene, and myrcene) in less than 80 s, using both standards and conifer branch enclosures (Norway spruce, Scots pine and Black pine). Five monoterpenes usually present in Norway spruce samples with a high abundance were separated even when the compound concentrations were diluted to 20 ppbv. Thus, fastGC-PTR-ToF-MS was shown to be an adequate one-instrument solution for plant monoterpene research.