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Publication
Desenvolvimento, validação e aplicação de uma metodologia para análise e quantificação de canabinóides em urina
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Authors
Abstract(s)
A canábis é a substância de abuso ilícita mais produzida e consumida em todo o mundo. Consequentemente os mercados ilícitos disponibilizam uma ampla gama de canábis e produtos de canábis com maiores níveis de tetrahidrocanabinol (THC), o componente psicoativo da canábis e que compreende vários isómeros e variantes estereoquímicas incluídas nas convenções internacionais do controlo de drogas.
O presente trabalho propõe uma nova metodologia para determinação de quatro analitos canabinóides, o CBD-OH, CBD-COOH, THC-OH, e THC-COOH em amostras de urina, através de microextração adsortiva em barra seguida de dessorção líquida e análise por cromatografia gasosa acoplada a espectrómetro de massa (BAμE-μLD/GC-MS). Esta é uma abordagem analítica inovadora, com grande simplicidade no uso, robustez e “mais verde”. A inovação do microdispositivo usado foi a possibilidade da escolha do sorvente mais adequado, que para os metabolitos a estudo supramencionados, revelou ser o sorvente C18 o mais seletivo.
O tempo mais eficaz para a derivatização dos analitos foi igualmente otimizado, tendo-se obtido melhores resultados em 2 minutos de derivatização no micro-ondas. As condições experimentais foram igualmente otimizadas usando desenho experimental, com melhores resultados com extração durante 90 min, sem adição de metanol a pH 2,1 e retroextração com acetonitrilo, durante 15 min, sob tratamento ultrassónico.
A otimização da metodologia aplicada permitiu recuperações entre 80% e 110%.
Cannabis is the world's most widely produced and used illicit substance of abuse. As a result, illicit markets offer a wide range of cannabis and cannabis products with higher levels of tetrahydrocannabinol (THC), the psychoactive component of cannabis and which includes several isomers and stereochemical variants included in international drug control conventions. The present work proposes a new methodology for the determination of four cannabinoid analytes, CBD-OH, CBD-COOH, THC-OH, and THC-COOH in urine samples, through adsorptive bar microextraction followed by liquid desorption and gas chromatography coupled to mass spectrometry (BAμE-μLD/GC-MS) analysis. This is an innovative analytical approach, with great simplicity in use and robustness, and "greener". The innovation of the microdevice used was the possibility of choosing the most appropriate sorbent, which for the metabolites mentioned above, proved to be the C18 the most selective. The most effective time for the derivatization of the analytes was also optimized, and better results were obtained in 2 minutes of derivatization in the microwave. The experimental conditions were also optimized using an experimental design, with better results with extraction for 90 min without the addition of methanol at pH 2.1 and backextraction with acetonitrile for 15 min under ultrasonic treatment. The optimization of the methodology applied allowed recoveries between 80% and 110%.
Cannabis is the world's most widely produced and used illicit substance of abuse. As a result, illicit markets offer a wide range of cannabis and cannabis products with higher levels of tetrahydrocannabinol (THC), the psychoactive component of cannabis and which includes several isomers and stereochemical variants included in international drug control conventions. The present work proposes a new methodology for the determination of four cannabinoid analytes, CBD-OH, CBD-COOH, THC-OH, and THC-COOH in urine samples, through adsorptive bar microextraction followed by liquid desorption and gas chromatography coupled to mass spectrometry (BAμE-μLD/GC-MS) analysis. This is an innovative analytical approach, with great simplicity in use and robustness, and "greener". The innovation of the microdevice used was the possibility of choosing the most appropriate sorbent, which for the metabolites mentioned above, proved to be the C18 the most selective. The most effective time for the derivatization of the analytes was also optimized, and better results were obtained in 2 minutes of derivatization in the microwave. The experimental conditions were also optimized using an experimental design, with better results with extraction for 90 min without the addition of methanol at pH 2.1 and backextraction with acetonitrile for 15 min under ultrasonic treatment. The optimization of the methodology applied allowed recoveries between 80% and 110%.
Description
Dissertação para obtenção do grau de Mestre no Instituto Universitário Egas Moniz
Keywords
Microextração adsortiva em barra (BAμE) Canabinóides Cromatografia em fase gasosa acoplada a espetrometria de massa (GC-MS) Amostras biológicas