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Estudo de N‐alquilamino 2’‐,3’‐ e 4’‐cloropropriofenonas por GC‐MS/MS e FT-ICR
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Resumo(s)
As novas substâncias psicoativas (NSP) são substâncias não controladas pelas Convenções das
Nações Unidas sobre drogas mas que constituem um potencial risco para a saúde pública. As catinonas
constituem o maior grupo de NSP aprendidas na Europa. Estes compostos são análogos sintéticos da
(S)-catinona, o principal alcaloide psicoativo presente na Catha edulis. A elevada velocidade com que
estas substâncias emergem nos mercados ilícitos torna a sua identificação um dos maiores desafios por
parte dos laboratórios forenses, quer seja pela falta de padrões ou pela necessidade de metodologias que
permitam identificar novos compostos e diferenciar isómeros.
Neste contexto e no âmbito da colaboração com o Laboratório da Policia Cientifica (LPC-PJ),
desenvolveram-se metodologias de análise por espetrometria de massa de ressonância ciclotrónica de
ião com transformada de Fourier (FT-ICR-MS) e de cromatografia em fase gasosa acoplada à
espetrometria de massa tandem (GC-MS/MS) com vista à diferenciação de cloro-catinonas. Analisaramse 20 cloro-catinonas organizadas em 8 grupos de regioisómeros diferindo na estrutura da amina e, em
cada grupo, na posição do átomo de cloro do anel aromático. Incluíram-se duas novas substâncias
sintetizadas no âmbito deste trabalho, a 3’-cloro-dietilcatinonta e 4’-cloro-dietilcatinona.
Os resultados mostraram que apenas pelos espetros de MS/MS obtidos por FT-ICR-MS com
ionização por electrospray e espetrometria de massa tandem com dissociação induzida por colisão é
possível diferenciar os regioisómeros de cloro-catinonas. Esta análise foi baseada nos intervalos de
aceitação das abundâncias relativas dos fragmentos característicos nos espectros de MS/MS, simulados
pelo método de Monte Carlo, considerando a dispersão estimada e a correlação das abundâncias iónicas.
A comparação destes intervalos com os obtidos pelas metodologias definidas pelas agências
internacionais WADA e ENFSI mostrou que a metodologia de simulação é mais efetiva na distinção de
cloro-catinonas isoméricas.
Identificou-se, ainda, a nova catinona N-isobutil-4-metil-1-fenilpentanona, por espetroscopia de
ressonância magnética nuclear, numa amostra fornecida pelo LPC-PJ.
New psychoactive substances (NPS) are substances that aren’t controlled by the United Nations Conventions on drugs, but that may pose a public health threat. Synthetic cathinones are the second largest seized group of NPS on Europe. These substances are synthetic analogues of (S)-cathinone, the main psychoactive alkaloid of Catha edulis. The high rate at which these compounds emerge on the market makes their identification one of the greatest challenges to forensic laboratories, due to the lack of standards and the absence of analytical methods for identifying novel compounds as well as to discriminate between different regioisomers. Thus, under the scope of the protocol between Ciências Ulisboa and the Laboratory of Scientific Police (LPC-PJ), analytic methods were developed using Fourier-Transform Ion Cyclotron Resonance mass spectrometry (FT-ICR-MS) and gas chromatography coupled to tandem mass spectrometry (CGMS/MS), to discriminate chloro-cathinones regioisomers. A group of 20 chloro-cathinones were analysed, divided in 8 groups which differ on the structure of the amino group and, in each group, on the position of the chlorine atom on the aromatic ring. Two new substances were synthetized this work and were included in the analysis, 3’-chloro-diethylcathinone and 4’-chloro-diethylcathinone. Using electrospray ionization coupled to FT-ICR- MS and using collision induced dissociation (MSMS) it was possible to differentiate all chloro-catinone’ regioisomers investigated. This new method of analysis is based on the characteristic fragments’ acceptance intervals of the relative abundances, simulated by the Monte Carlo method, considering the estimated dispersion and the correlation of ionic abundances. The comparation of these intervals with those of international agencies WADA and ENFSI demonstrated that the simulation methodology is more effective on the distinction of isomeric chlorocathinones. Moreover, N-iso-butyl-4-methyl-1-phenylpentanone, a new cathinone, was identified, in a sample provided by the LPJ-PJ, using nuclear magnetic resonance spectroscopy (NMR).
New psychoactive substances (NPS) are substances that aren’t controlled by the United Nations Conventions on drugs, but that may pose a public health threat. Synthetic cathinones are the second largest seized group of NPS on Europe. These substances are synthetic analogues of (S)-cathinone, the main psychoactive alkaloid of Catha edulis. The high rate at which these compounds emerge on the market makes their identification one of the greatest challenges to forensic laboratories, due to the lack of standards and the absence of analytical methods for identifying novel compounds as well as to discriminate between different regioisomers. Thus, under the scope of the protocol between Ciências Ulisboa and the Laboratory of Scientific Police (LPC-PJ), analytic methods were developed using Fourier-Transform Ion Cyclotron Resonance mass spectrometry (FT-ICR-MS) and gas chromatography coupled to tandem mass spectrometry (CGMS/MS), to discriminate chloro-cathinones regioisomers. A group of 20 chloro-cathinones were analysed, divided in 8 groups which differ on the structure of the amino group and, in each group, on the position of the chlorine atom on the aromatic ring. Two new substances were synthetized this work and were included in the analysis, 3’-chloro-diethylcathinone and 4’-chloro-diethylcathinone. Using electrospray ionization coupled to FT-ICR- MS and using collision induced dissociation (MSMS) it was possible to differentiate all chloro-catinone’ regioisomers investigated. This new method of analysis is based on the characteristic fragments’ acceptance intervals of the relative abundances, simulated by the Monte Carlo method, considering the estimated dispersion and the correlation of ionic abundances. The comparation of these intervals with those of international agencies WADA and ENFSI demonstrated that the simulation methodology is more effective on the distinction of isomeric chlorocathinones. Moreover, N-iso-butyl-4-methyl-1-phenylpentanone, a new cathinone, was identified, in a sample provided by the LPJ-PJ, using nuclear magnetic resonance spectroscopy (NMR).
Descrição
Tese de Mestrado, Química, 2023, Universidade de Lisboa, Faculdade de Ciências
Palavras-chave
NSP Catinonas Sintéticas Isómeros FT-ICR-MS MS/MS Teses de mestrado - 2023