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Determinação de biomarcadores de consumo de tabaco e cafeína em águas residuais
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| 1.92 MB | Adobe PDF |
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Abstract(s)
O tabaco é responsável por milhões de mortes em todo o mundo. O seu consumo provoca efeitos adversos não só a indivíduos fumadores como também a pessoas não fumadoras expostas ao fumo do tabaco. O impacto causado pelo tabagismo enfatiza a importância da monitorização do seu consumo para que possam ser desenvolvidas e aplicadas medidas que permitam a prevenção e cessação de hábitos tabágicos. A epidemiologia baseada em águas residuais é uma abordagem emergente, com elevada aplicabilidade e capaz de colmatar as limitações das abordagens tradicionais. As metodologias mais comummente empregues neste contexto envolvem um passo de preparação de amostra que envolve extração em fase sólida seguida de cromatografia líquida acoplada à espetrometria de massa. A preocupação com a execução de uma química mais verde levou, nos últimos anos, ao desenvolvimento de técnicas de extração miniaturizadas que permitam a extração de compostos de forma mais ecológica, sem descurar a performance analítica.
No presente estudo foi otimizada, validada e aplicada uma metodologia baseada em microextração adsortiva em barra para proceder à extração de nicotina e do seu biomarcador, cotinina, em águas residuais, seguido de dessorção líquida e análise por cromatografia gasosa acoplada a espetrometria de massa.
O método proposto apresentou uma boa linearidade (r2 ≥ 0,995) para ambos os compostos no intervalo de concentrações de 2,5 a 100,0 μg/L. A metodologia revelou também ser precisa (RSD ≤ 20%). Embora não tenha sido possível recuperar totalmente os analitos em estudo da matriz aquosa, a metodologia analítica demonstrou que a recuperação de nicotina e cotinina é reprodutível. A extração adsortiva em barra demonstrou capacidade de ser aplicada em contextos reais de WBE e, revelou ser mais “verde” que as técnicas clássicas de extração empregues e descritas na literatura.
A abordagem analítica proposta apresenta igualmente potencial de aplicabilidade para a monitorização destas e de outras substâncias prioritárias em matrizes complexas, em particular quando combinadas com cromatografia líquida acoplada à espectrometria de massa em tandem.
Tobacco is responsible for millions of deaths worldwide. Its consumption causes adverse effects not only to individual smokers but also to non-smokers exposed to tobacco smoke. The impact caused by smoking emphasizes the importance of monitoring tobacco consumption so that measures can be developed and implemented for the prevention and cessation of smoking. Wastewater-based epidemiology is an emerging approach, with high applicability and capable of overcoming the limitations of traditional approaches. The most employed methodologies in this context involve a sample preparation step involving solid phase extraction followed by liquid chromatography coupled to mass spectrometry. The concern with the implementation of greener chemistry has led, in recent years, to the development of miniaturized extraction techniques that allow the extraction of compounds in a more environmentally friendly manner, without neglecting analytical performance. In the present study, a methodology based on bar microextraction was optimized, validated and applied to perform the extraction of nicotine and its biomarker, cotinine, in wastewater, followed by liquid desorption and analysis by gas chromatography coupled with mass spectrometry. The proposed method showed good linearity (r2 ≥ 0.995) for both compounds in the concentration range from 2.5 to 100.0 μg/L. The methodology also proved to be accurate (RSD ≤ 20%). Although it was not possible to fully recover the analytes under study from the aqueous matrix, the analytical methodology demonstrated that the recovery of nicotine and cotinine is reproducible. The adsorptive bar extraction showed ability to be applied in real WBE contexts and, revealed to be "greener" than the classical extraction techniques employed and described in the literature. The proposed analytical approach also presents potential applicability for monitoring these and other priority substances in complex matrices, in particular when combined with liquid chromatography coupled to tandem mass spectrometry.
Tobacco is responsible for millions of deaths worldwide. Its consumption causes adverse effects not only to individual smokers but also to non-smokers exposed to tobacco smoke. The impact caused by smoking emphasizes the importance of monitoring tobacco consumption so that measures can be developed and implemented for the prevention and cessation of smoking. Wastewater-based epidemiology is an emerging approach, with high applicability and capable of overcoming the limitations of traditional approaches. The most employed methodologies in this context involve a sample preparation step involving solid phase extraction followed by liquid chromatography coupled to mass spectrometry. The concern with the implementation of greener chemistry has led, in recent years, to the development of miniaturized extraction techniques that allow the extraction of compounds in a more environmentally friendly manner, without neglecting analytical performance. In the present study, a methodology based on bar microextraction was optimized, validated and applied to perform the extraction of nicotine and its biomarker, cotinine, in wastewater, followed by liquid desorption and analysis by gas chromatography coupled with mass spectrometry. The proposed method showed good linearity (r2 ≥ 0.995) for both compounds in the concentration range from 2.5 to 100.0 μg/L. The methodology also proved to be accurate (RSD ≤ 20%). Although it was not possible to fully recover the analytes under study from the aqueous matrix, the analytical methodology demonstrated that the recovery of nicotine and cotinine is reproducible. The adsorptive bar extraction showed ability to be applied in real WBE contexts and, revealed to be "greener" than the classical extraction techniques employed and described in the literature. The proposed analytical approach also presents potential applicability for monitoring these and other priority substances in complex matrices, in particular when combined with liquid chromatography coupled to tandem mass spectrometry.
Description
Dissertação para obtenção do grau de Mestre no Instituto Universitário Egas Moniz
Keywords
Epidemiologia de águas residuais Microextração adsortiva em barra Tabaco Cromatografia gasosa acoplada a espetrometria de massa