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Authors
Abstract(s)
A exposição à poluição tabágica ambiental constitui um sério problema de saúde pública, já
que os fumadores passivos estão expostos a mais de quatro mil substâncias tóxicas, entre as
quais dezenas de cancerígenos e nicotina, principal agente responsável pelo desenvolvimento
da dependência ao tabaco. Este alcalóide de ocorrência natural deriva das folhas de tabaco e
é rápida e extensivamente metabolizado no fígado para formar uma larga variedade de
metabolitos. A exposição crónica à nicotina, a droga mais consumida em todo o planeta, é
responsável pela aparição de problemas de saúde como cancro, doenças do foro respiratório e
neurológico, entre outros.
Como problema de saúde pública, é uma prioridade conhecer a verdadeira prevalência de
indivíduos expostos a este tipo de poluição. Assim o principal objectivo do presente estudo é
a determinação de nicotina e os seus principais metabolitos, cotinina e trans-3-
hidroxicotinina em amostras de fluido oral por cromatografia gasosa acoplada a
espectrometria de massa em tandem, de forma a avaliar a exposição de não fumadores a
estas substâncias.
A metodologia proposta foi validada de acordo com critérios internacionalmente aceites para
a validação de métodos bioanalíticos da Food and Drug Administration (FDA). Utilizando
apenas 200 μL de amostra, o método demonstrou ser linear no intervalo de concentrações de
0,5 a 1000 ng/mL, exacto e preciso. Os limites de detecção e quantificação foram de 0,5
ng/mL e a eficiência de extracção foi superior a 85% para todos os compostos de estudo.
Tendo em conta os resultados obtidos, podemos afirmar que a cromatografia gasosa acoplada
a espectrometria de massa em tandem é uma poderosa e indispensável ferramenta que
providencia uma elevada sensibilidade para a quantificação simultânea de biomarcadores de
exposição ao fumo de tabaco num volume reduzido de fluido oral.
Exposure to tobacco smoke is a serious public health problem, since the passive smokers are exposed to more than four thousand toxic substances, including dozens of carcinogens and nicotine, the main agent responsible for the development of tobacco dependence. This naturally occurring alkaloid derives from tobacco leaves and is rapidly and extensively metabolized in the liver to form a wide variety of metabolites. Chronic exposure to nicotine, the most abused drug on the planet, is responsible for the appearance of health problems like cancer, respiratory and neurological diseases, etc. As a public health problem, it is a priority to know the real prevalence of exposed individuals. Thus the main objective of this study was the determination of nicotine and its major metabolites, cotinine and trans-3-hydroxycotinine, in oral fluid samples by gas chromatography coupled to tandem mass spectrometry, in order to assess the exposure of non-smoking individuals to those substances. The proposed methodology was validated according to internationally accepted criteria for bioanalytical method validation, namely those from the Food and Drug Administration. Using a sample amount as low as 200 µL, the method proved to be linear from 0.5 to 1000 ng/mL, precise and accurate. The limits of detection and quantification were 0.5 ng/mL and the extraction efficiencies were higher than 85% for all studied compounds. As regards the obtained results, we can say that gas chromatography coupled to tandem mass spectrometry is a powerful and indispensable tool that provides high sensitivity for the simultaneous measurement of biomarkers of exposure to tobacco smoke in small volumes of oral fluid.
Exposure to tobacco smoke is a serious public health problem, since the passive smokers are exposed to more than four thousand toxic substances, including dozens of carcinogens and nicotine, the main agent responsible for the development of tobacco dependence. This naturally occurring alkaloid derives from tobacco leaves and is rapidly and extensively metabolized in the liver to form a wide variety of metabolites. Chronic exposure to nicotine, the most abused drug on the planet, is responsible for the appearance of health problems like cancer, respiratory and neurological diseases, etc. As a public health problem, it is a priority to know the real prevalence of exposed individuals. Thus the main objective of this study was the determination of nicotine and its major metabolites, cotinine and trans-3-hydroxycotinine, in oral fluid samples by gas chromatography coupled to tandem mass spectrometry, in order to assess the exposure of non-smoking individuals to those substances. The proposed methodology was validated according to internationally accepted criteria for bioanalytical method validation, namely those from the Food and Drug Administration. Using a sample amount as low as 200 µL, the method proved to be linear from 0.5 to 1000 ng/mL, precise and accurate. The limits of detection and quantification were 0.5 ng/mL and the extraction efficiencies were higher than 85% for all studied compounds. As regards the obtained results, we can say that gas chromatography coupled to tandem mass spectrometry is a powerful and indispensable tool that provides high sensitivity for the simultaneous measurement of biomarkers of exposure to tobacco smoke in small volumes of oral fluid.
Description
Keywords
Tabagismo Tabaco - Nicotina Tabaco - Marcadores biológicos Fumadores - Fluído oral - Análise Cromatografia gasosa
Citation
Publisher
Universidade da Beira Interior