New psychoactive substances – new analytical challenges and approaches

Hulme, Matthew Carl (2018) New psychoactive substances – new analytical challenges and approaches. Doctoral thesis (PhD), Manchester Metropolitan University.

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Abstract

In recent years Novel Psychoactive Substances (NPS), including diphenidine and ephenidine, have emerged and an increase in the number of substances encountered each year has increased, even with the introduction of the Psychoactive Substances Act (2016).1 More derivatives are also reported containing fluorine substituents due to the increased stability.2 The appearance of novel fluorinated substances creates analytical challenges for their detection. This results in the need for the development of new rapid, selective and inexpensive analytical methods for both their separation and detection. Colour test reagents are commonly used for the presumptive testing of these emerging substances, however as the number of encountered compounds increases so does the number of false positives produced with these tests.3 Gas Chromatography-Mass Spectroscopy (GC-MS) is also a commonly used method for the detection and separation of controlled substances, with methods reported previously for fluorinated cathinones.4 However, it also reports on the tailing of peaks through thermal degradation, which makes separation of regioisomers difficult. This thesis demonstrates the synthesis of a number of fluorinated and non- fluorinated diphenidine and ephenidine derivatives. Synthesis of fluorinated diphenidine analogues will also outline the ease of production of NPS along with the difficulties in their detection and separation. The use of presumptive colour testing shows the difficulty of distinguishing between regioisomers, as well as the increase to the number of false positives. The development of GC-MS methods has aided with the separation and detection of diphenidine and ephenidine derivatives. A method has also been developed and validated for the identification of fluorinated cathinones and amphetamines with improved symmetry and a removal of any tailing/fronting. Runs for all separation and identification last 20 minutes or longer. 60 MHz NMR has the ability to perform 1H and 19F NMR experiments, while still providing matching spectrum patterns and splitting to higher-powered magnets. This is utilised for the detection of diphenidine, ephenidine, cathinone and amphetamine derivatives with the ability to distinguish between regioisomers. 2D NMR experiments can also allow for further identification of difluorinated ephenidine derivatives. This allows for the possibility of using 60 MHz NMR as a presumptive test for NPS. The use of 19F NMR experiments also provides an ability to perform quantitative analysis. Street samples can then be analysed both quantitatively and quantitatively, using 60 MHz NMR, with results confirmed by GC-MS. All 1H and 19F NMR experiments occur within 5 minutes meaning detection can occur rapidly which aids with forensic testing and shows that 60 MHz instrumentation can be utilised at locations such as festivals, airport security and police custody.