Browsing by Author "Pinho, C."
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- Bisphenol a releasing by plastic container with gas chromatography tandem mass spectometryPublication . Rocha, S.; Domingues, V.F.; Mansilha, C.; Pinho, C.; Gameiro, P.; Delerue-Matos, C.
- Emerging water contaminantsPublication . Mansilha, C.; Melo, A.; Ferreira, I.; Domingues, V.; Pinho, C.; Rocha, S.; Gameiro, P.
- Evaluation of the actual standard procedures for analysis of total extractable hydrocarbons in environmental water matricesPublication . Pinho, C.; Mansilha, C.; Gameiro, P.Hundreds of different hydrocarbon compounds derived from agricultural, industrial and domestic practices are released daily into aquatic systems with adverse effects in the desirable potable characteristics, in aquatic fauna and flora, and on tourism, recreation and aesthetics of the impacted areas. Total petroleum hydrocarbon concentration data cannot be used to quantitatively estimate human health risk, but can be used as an important tool for three purposes: verifying if there is a problem, assessing the severity of the contamination and following the progress of a remediation effort. The objective of this work was the optimization of the experimental conditions for the determination of total hydrocarbons in water by liquid–liquid extraction coupled to infrared spectrophotometry, with the goal of improving the qualitative information provided by the spectra. The method was validated with satisfactory detection and quantification limits and demonstrated acceptable levels of precision, accuracy and analyte recoveries. Solid phase extraction and microwave assisted extraction procedures were tested and compared to the liquid extraction. Additionally, a spectra library was prepared with different natural and synthetic oils. The developed method was applied to the analysis of Portuguese inland and coastal bathing waters and wastewaters and their compliance with national and European legislation was assessed.
- Groundwater from infiltration galleries used for small public water supply systems: contamination with pesticides and endocrine disruptorsPublication . Mansilha, C.; Melo, A.; Ferreira, I.; Pinho, O.; Domingues, V.; Pinho, C.; Gameiro, P.Infiltration galleries are among the oldest known means used for small public water fountains. Owing to its ancestral origin they are usually associated with high quality water. Thirty-one compounds, including pesticides and estrogens from different chemical families, were analysed in waters from infiltration galleries collected in Alto Douro Demarcated Wine region (North of Portugal). A total of twelve compounds were detected in the water samples. Nine of these compounds are described as presenting evidence or potential evidence of interfering with the hormone system of humans and wildlife. Although concentrations of the target analytes were relatively low, many of them below their limit of quantification, four compounds were above quantification limit and two of them even above the legal limit of 0.1 μg/L: dimethoate (30.38 ng/L), folpet (64.35 ng/L), terbuthylazine-desethyl (22.28 to 292.36 ng/L) and terbuthylazine (22.49 to 369.33 ng/L).
- Quantification of endocrine disruptors and pesticides in water by gas chromatography-tandem mass spectrometry. Method validation using weighted linear regression schemesPublication . Mansilha, C.; Melo, A.; Rebelo, H.; Ferreira, I.M.; Pinho, O.; Domingues, V.; Pinho, C.; Gameiro, P.A multi-residue methodology based on a solid phase extraction followed by gas chromatography-tandem mass spectrometry was developed for trace analysis of 32 compounds in water matrices, including estrogens and several pesticides from different chemical families, some of them with endocrine disrupting properties. Matrix standard calibration solutions were prepared by adding known amounts of the analytes to a residue-free sample to compensate matrix-induced chromatographic response enhancement observed for certain pesticides. Validation was done mainly according to the International Conference on Harmonisation recommendations, as well as some European and American validation guidelines with specifications for pesticides analysis and/or GC-MS methodology. As the assumption of homoscedasticity was not met for analytical data, weighted least squares linear regression procedure was applied as a simple and effective way to counteract the greater influence of the greater concentrations on the fitted regression line, improving accuracy at the lower end of the calibration curve. The method was considered validated for 31 compounds after consistent evaluation of the key analytical parameters: specificity, linearity, limit of detection and quantification, range, precision, accuracy, extraction efficiency, stability and robustness.