Determination of mercury and antimony in environmental and food matrices: development of analytical methodology and migration studies
Food safety is an issue of vital importance in the world. It must be sustained so as to avoid pollution episodes in food, which subsequently could cause potential risks to health. The main approach of this thesis consist of the study of two particular food contamination cases: primary contamination...
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| Formato: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | España |
| Recursos: | CBUC, CESCA |
| Repositorio: | TDR. Tesis Doctorales en Red |
| OAI Identifier: | oai:www.tdx.cat:10803/401592 |
| Acesso em linha: | http://hdl.handle.net/10803/401592 |
| Access Level: | acceso abierto |
| Palavra-chave: | Especiació (Química) Especiación (Química) Speciation (Chemistry) Mercuri Mercurio Mercury Antimoni Antimonio Antimony Seguretat alimentària Seguridad alimentaria Food security Ciències Experimentals i Matemàtiques 543 |
| Resumo: | Food safety is an issue of vital importance in the world. It must be sustained so as to avoid pollution episodes in food, which subsequently could cause potential risks to health. The main approach of this thesis consist of the study of two particular food contamination cases: primary contamination of the aquatic media and the corresponding seafood with mercury, and direct contamination of beverages due to polyethylene terephthalate containers (PET) with antimony. To carry out these studies, the work was structured in three sections. The first one is the development of analytical methodology for the correct determination of mercury and antimony, in which atomic fluorescence spectrometry and inductive coupled plasma mass spectrometry were used to know the total content, whereas the coupling of the liquid chromatography to these detector was used for speciation. Additionally, online preconcentration methods for the speciation of these elements were successfully developed to determine the trace amounts present in the matrices under study, comprising tap and PET-bottled waters. The second section deals with the application of the developed methodology in real samples. Antimony was determined in PET-bottled waters, juices, spirits and PET bottles, obtaining concentrations under the limits established for the European Union, and different species depending on the matrix: Sb(V) for waters, Sb(III) for juices and both for spirits and PET extracts. Mercury was determined in seafood, obtaining concentrations beyond the limits for four predator fish, being methylmercury the predominant species. The third section consists of the study of the mechanisms of antimony migration from PET to beverages. To know the main variables which enhances migration, studies with waters, juices and spirits were performed at different times and temperatures. Results demonstrated that high temperatures (60ºC) enhanced migration, as antimony concentration rapidly increased and the limit permitted was exceeded in waters and spirits. Differences among the matrices studied and the tendencies observed throughout time demonstrated that not only temperature, but also matrix characteristics and the type of PET had influence on migration. These facts were demonstrated with the performance of crossed migration experiments, using different types of PET bottles for the storage of the aforementioned matrices. |
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