A method was developed for the analysis of 31 pharmaceutical compounds in Lisbon's drinking water system, using solid-phase extraction (SPE) and ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). The method was validated through estimation of the linearity range, method detection and quantification limits, matrix effects, precision and accuracy. The method detection and quantification limit ranges were 0.009-10 and 0.03-33 ng/L, respectively. Analytes were quantified in water samples collected from the EPAL (Empresa Portuguesa das Águas Livres S.A.) supply system. Carbamazepine, atenolol, sulfadiazine, sulfamethazine, sulfapyridine, sulfamethoxazole, acetaminophen, caffeine and erythromycin were quantified in the analysed samples.

O desenvolvimento de metodologias para a determinação de óleos e gordura (OG) apresenta inúmeras dificuldades e desafios para laboratórios analíticos, principalmente na análise de água potável devido ao seu baixo valor paramétrico. O método de FTIR após extração com tetracloroetileno foi desenvolvido para o monitoramento e controle de OG em vários tipos de água, tais como águas naturais (água superficial, água subterrânea e água de banho), efluentes e água potável. O método foi validado após aplicação de testes estatísticos e cálculo da estimativa de incertezas, e provou ser uma boa alternativa ao Freon 113. Os resultados referentes aos estudos de linearidade, recuperação, precisão, limites de detecção, limites de quantificação e estimativa de incerteza são apresentados e discutidos. O método validado foi aplicado às várias matrizes de água e demonstrou ser adequado ao monitoramento de óleos e gordura nestas matrizes em concentrações maiores que 0,01 mg L-1.

The development of methods for oils and grease (OG) determination presents several difficulties and challenges for analytical laboratories, mainly for drinking water analysis regarding its low parametric value. FTIR method with tetrachloroethylene was developed for OG monitoring and control in several water matrices, such as natural waters (surface water, groundwater and bathing water), wastewaters and drinking water. The method was validated through the application of statistical tests and calculus of the uncertainty of the analytical assay, and proved to be a good alternative to Freon 113. Results regarding the calibration, linearity, OG recovery, precision, limits of detection and quantification, and uncertainty estimation are presented and discussed. The validated method was applied for the analysis of water samples from all studied matrices and was found to be appropriate for monitoring oil and grease in these matrices at levels higher than 0.01 mg L-1.

The aim of this work was to study the influence of green tea consumption on fluoride ingestion. The extraction conditions of fluorides from green tea infusions were defined and nine brands of green tea available in Portugal were analyzed. The quantification of fluorides in the green tea was preceded by the implementation and validation of the potentiometric method (commercial fluoride selective electrode). The concentration of fluorides in the samples ranged from 0. 8 to 2. 0 mg L-1.

Desenvolvimento e validação de um método de micro-extração em fase sólida acoplado à cromatografia gasosa com detector de ionização de chama (SPME-GC-FID) para a monitorização de dezesseis PAHs definidos como poluentes em amostras de água pela US EPA. As melhores condições de extração foram obtidas utilizando uma fibra de PDMS 30 µm, extração direta a 60 ºC durante 30 min sob agitação (1500 rpm) e com 10% de NaCl. O método mostrou ter uma boa linearidade (R² > 0,99), repetibilidade e recuperação (> 71%). Os limites de detecção estão compreendidos entre 0,06 e 0,5 µg L-1. Foram efectuados outros estudos, tais como, de estabilidade, análises repetidas sobre a mesma amostra, precisão intermédia e influência da concentração do cloro residual na recuperação dos PAHs. O método foi aplicado a várias amostras de água, incluindo água de consumo humano e águas ambientais (subterrâneas, superficiais e água da chuva).

A procedure based on solid phase microextraction (SPME) and gas chromatography with flame ionization detection (GC-FID) was developed and validated in order to determine the sixteen US EPA PAH (polynuclear aromatic hydrocarbons) compounds in water samples. The best analytical conditions were obtained using PDMS 30 µm fibre by direct immersion at 60 ºC, 30 min, 1500 rpm and 10% NaCl. The method showed good linearity (R² > 0.99), repeatability (< 10%) and recovery (> 71%). The detection limits were between 0.06 and 0.50 µg L-1. Other studies were also carried out, such as stability studies, repeated analysis on the same sample, intermediate precision and the influence of chlorine concentration in the recovery of the PAHs. This method was applied to several matrices, including tap water and real environmental samples (surface and underground water and rainwater).