Percorrer por autor "Gameiro, Paula"
A mostrar 1 - 6 de 6
Resultados por página
Opções de ordenação
- Analysis of total extractable hydrocarbons in environmental water samples. Implementation and validation of a FT-IR methodPublication . Pinho, Carina; Melo, Armindo; Mansilha, Catarina; Gameiro, Paula
- Bathing waters: new directive, new standards, new quality approachPublication . Mansilha, Catarina; Coelho, Carla; Heitor, Ana; Amado, João; Martins, Joaquim; Gameiro, PaulaBathing water quality is an important public health issue, mainly because of fecal contamination. In 2006, the European Commission (EC) adopted a new directive with respect to recreational bathing waters that calls for stricter standards and reduces the number of laboratory tests done in routine beach monitoring from nineteen to two bacterial indicators, namely, Escherichia coli and intestinal enterococci, replacing policies of the EC Bathing Water Directive that have existed since 1976. Our practice in Portugal is in line with this international development, and this study demonstrates the equivalency of the new bacteriological parameters with the old. The water quality of 25 coastal beaches was surveyed using both new and old microbiological indicators of fecal contamination. Statistical analysis demonstrated equivalency of the results obtained for fecal coliforms with Escherichia coli and for fecal streptococci with intestinal enterococci.
- Bisphenol A migration from plastic materials: direct insight of ecotoxicity in Daphnia magnaPublication . Mansilha, Catarina; Silva, Poliana; Rocha, Sónia; Gameiro, Paula; Domingues, Valentina; Pinho, Carina; Ferreira, IsabelBisphenol A (BPA) is an endocrine disrupting chemical (EDC) whose migration from food packaging is recognized worldwide. However, the real overall food contamination and related consequences are yet largely unknown. Among humans, children exposition to BPA contamination has been emphasized because the immaturity of their biological systems. The main aim of this study was to assess the reproductive burden of BPA leached from commercially available plastic containers used or related to child nutrition, performing ecotoxicological tests using the biomonitoring specie Daphnia magna. Acute and chronic tests, as well as single and multigenerational tests were done. Migration of BPA from several baby bottles and other plastic containers evaluated by GC-MS indicated that a broader range of foodstuff may be contaminated when packed in plastics. Ecotoxicological tests results performed using defined concentrations of BPA were in agreement with literature, although a precocious maturity of daphnids was detected at 3.0 mg/L. Curiously, an increased reproductive output (embryos per female) was observed when daphnids were bred in the polycarbonate (PC) containers (145.1±4.3% to 264.7±3.8%), both in single as in multigenerational tests, in comparison with the negative control group (100.3±1.6%). A strong correlated dose-dependent ecotoxicological effect was observed, providing evidence that BPA leached from plastic food packaging materials act as functional estrogen in vivo at very low concentrations. In contrast, embryo production by daphnids cultured in polypropylene and non-PC bottles, was slightly but not significantly enhanced (92.5±2.0% to 118.8±1.8%). Multigenerational tests also revealed magnification of the adverse effects, not only on fecundity but also on mortality, which represents a worrying trend for organisms that are chronically exposed to xenoestrogens for many generations. Two plausible explanations for the observed results could be given: a non-monotonic dose-response relationship or a mixture toxicity effect.
- Interlaboratory validation of an environmental monitoring method for trace analysis of endocrine disrupting compoundsPublication . Mansilha, Catarina; Rocha, Sonia; Gameiro, Paula; Carina Pinho, Carina; Ferreira, Isabel M. P. L. V. O.; Silva, Poliana; Domingues, ValentinaEnvironmental pollution continues to be an emerging study field, as there are thousands of anthropogenic compounds mixed in the environment whose possible mechanisms of toxicity and physiological outcomes are of great concern. Developing methods to access and prioritize the screening of these compounds at trace levels in order to support regulatory efforts is, therefore, very important. A methodology based on solid phase extraction followed by derivatization and gas chromatography-mass spectrometry analysis was developed for the assessment of four endocrine disrupting compounds (EDCs) in water matrices: bisphenol A, estrone, 17b-estradiol and 17a-ethinylestradiol. The study was performed, simultaneously, by two different laboratories in order to evaluate the robustness of the method and to increase the quality control over its application in routine analysis. Validation was done according to the International Conference on Harmonisation recommendations and other international guidelines with specifications for the GC-MS methodology. Matrix-induced chromatographic response enhancement was avoided by using matrix-standard calibration solutions and heteroscedasticity has been overtaken by a weighted least squares linear regression model application. Consistent evaluation of key analytical parameters such as extraction efficiency, sensitivity, specificity, linearity, limits of detection and quantification, precision, accuracy and robustness was done in accordance with standards established for acceptance. Finally, the application of the optimized method in the assessment of the selected analytes in environmental samples suggested that it is an expedite methodology for routine analysis of EDC residues in water matrices.
- Occurrence of Bisphenol A, Estrone, 17β-Estradiol and 17α-Ethinylestradiol in Portuguese RiversPublication . Rocha, Sónia; Domingues, Valentina F.; Pinho, Carina; Fernandes, Virgínia C.; Delerue-Matos, Cristina; Gameiro, Paula; Mansilha, CatarinaThis study focused on the occurrence of several EDCs including bisphenol A, estrone (E1), the 17b-estradiol (E2) and 17a-ethinylestradiol (EE2) in fourteen rivers of Portugal. Samples analysis revealed a widespread contamination of BPA especially in Ave, Ca´vado, Douro, Ferro, Sousa and Vizela Rivers. Achieving 98.4 ng/L for the highest concentration. The estrogens achieved above the method quantification limit (MQL) were E1 in A ´ gueda River and E2 in Ave, Lima and Taˆmega Rivers. The maximum concentration detected for E1 was 26.9 ng/L. EE2 was detected only below MQL.
- Optimization of conditions for anthocyanin hydrolysis from red wine using response surface methodology (RSM)Publication . Pinho, Carina; Mansilha, Catarina; Gameiro, PaulaOptimization of conditions for anthocyanin hydrolysis from red wine was investigated using response surface methodology. The aglycon forms of the anthocyanins were quantified by high-performance liquid chromatography with diode array detection. The combined effects of three independent variables, HCl amount, heating temperature, and hydrolysis time, were studied using a 2(3) full-factorial central composite design. Anthocyanin hydrolysis yield depended mainly on the heating temperature and time of hydrolysis. HCl amount was the factor that least influenced the hydrolysis of anthocyanins. From experimental results, the maximum yield of anthocyanidins was reached with 9.8 mL of HCl (32% v/v), a heating temperature of 166.2 °C, and a hydrolysis time of 46.6 min. Five anthocyanidins, namely, delphinidin, cyanidin, petunidin, peonidin, and malvidin, were quantified in red wine. The reliability of the method was confirmed by recovery experiments, performed under optimal conditions. Recoveries indicated that anthocyanidins resisted the hydrolysis conditions.