Título: | STUDIES RELATED TO THE BEHAVIOUR OF NI AND PB IN ORGANIC SOLVENTS STABILIZAED IN MICROEMULSION BY GFAAS | ||||||||||||||||||||||||||||||||||||
Autor: |
MARIELA NORMA MATOS REYES |
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Colaborador(es): |
REINALDO CALIXTO DE CAMPOS - Orientador |
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Catalogação: | 11/MAR/2004 | Língua(s): | PORTUGUESE - BRAZIL |
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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. |
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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 |
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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.
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