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Título: STUDIES RELATED TO THE BEHAVIOUR OF NI AND PB IN ORGANIC SOLVENTS STABILIZAED IN MICROEMULSION BY GFAAS
Autor: MARIELA NORMA MATOS REYES
Colaborador(es): REINALDO CALIXTO DE CAMPOS - Orientador
Catalogação: 11/MAR/2004 Língua(s): PORTUGUESE - BRAZIL
Tipo: TEXT Subtipo: THESIS
Notas: [pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio.
[en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio.
Referência(s): [pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=4635&idi=1
[en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=4635&idi=2
DOI: https://doi.org/10.17771/PUCRio.acad.4635
Resumo:
The behaviour of Ni and Pb in different organic liquids relatively to their determination by GFAAS was investigated. The following organic liquids were studied: n- hexane, n-heptane, n-octane, isooctane, toluene, n-decane, hexadecane and mixtures of n-octane + acetone (99+1, v/v), n-octane + bromoform (99+1, v/v), and n-octane + carbon disulfide (99+1, v/v). Concerning stability, ng ml-1 solutions prepared by direct dissolution of organic standards in the different organic liquids showed significant Ni and Pb losses after only few minutes. No clear loss pattern related to chain length or form could be observed, although the losses were systematically slower when the O, S and Br compounds were present. Excellent long term sample stabilization was observed for the different organic media investigated if microemulsions are used. Microemulsions were prepared by mixing 6.5 ml of propan-1-ol with 3.3 ml of the organic liquid and 0.1 ml of 50% v/v HNO3. Ni and Pb could be added in the aqueous or aqueous forms. Conventional aqueous modification was allowed as well as Ir as permanent modifier. The dry and ramp steps showed to influence sensitivity, and must be carefully optimized. The same sensitivity was observed for the different microemulsion stabilized organic media. Thus, calibration with microemulsions prepared with a single organic solvent was possible. Commercial gasoline and diesel samples were analyzed after microemulsion stabilization and by a comparative procedure. Good concordance between both procedures was observed. Detection limits (k=3) in the original gasoline or diesel samples, derived from ten blank measurements were 4.5 and 3.6 µgl-1 for Ni and Pb, respectively, well above the values found in the analyzed samples.
Descrição: Arquivo:   
COVER, ACKNOWLEDGEMENTS, RESUMO, ABSTRACT, SUMMARY AND LISTS PDF      
CHAPTER 1 PDF      
CHAPTER 2 PDF      
CHAPTER 3 PDF      
CHAPTER 4 PDF      
CHAPTER 5 PDF      
REFERENCES AND ANNEX PDF