Título: | DETERMINATION OF SN IN HUMAN MILK BY GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY | |||||||
Autor: |
RENATO MARÇULLO BORGES |
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Colaborador(es): |
REINALDO CALIXTO DE CAMPOS - Orientador MARIA DE FATIMA RAMOS MOREIRA - Coorientador |
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Catalogação: | 18/DEZ/2009 | 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=14735&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=14735&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.14735 | |||||||
Resumo: | ||||||||
Tin is a metal of natural occurrence which is mainly extracted from the
mineral cassiterite, SnO2. Tin may be released to the atmosphere from both
natural and anthropogenic sources. In nature, it occurs in both inorganic and
organic forms, and the shorter the organic chain associated to the metal, the
higher the toxicity of the compound. Organotin compounds can penetrate cell
membranes and cause damage to cell, interrupt oxidative phosphorylation and
damage mitochondria. They can be immunotoxic and genotoxic. Human milk is
the ideal food for newborns due to its composition and availability. Human milk
is the fundamental food for infants, thus breast feeding is greatly encouraged up
to 2 years. However, it is also the major source of exposition to exogenous
substances for newborns, including tin and its compounds, since breast milk can
also be a route of maternal excretion of undesired environmental pollutants. The
direct GF AAS analysis of products such as milk is very attractive, due to the
inherent simplicity, and decrease in the sample preparation time and
contamination chances. In the present work, a transversally heated graphite
atomizer was used. Pyrolysis and atomization temperatures curves led to
pyrolysis and atomization temperatures of 1300 and 2200ºC, respectively, using
a sample volume of 20 µL. The use of a 1+1 dilution factor using 0.2% v/v
HNO(3) as diluent showed to be the best choice, as well as a modifier mass of
10+5 µg of palladium+magnesium, respectively. The modifier solution volume
was 10µL. In all cases, the background attenuation was well within the limits of
the Zeeman effect based background corrector. The analytical curve was linear
up to 300 µg L(-1), in both aqueous medium as well as in the presence of the
matrix. Calibration had to be performed with matrix matched calibration
solutions, using a blank level sample. The limit of detection (n=10, k=3) in the
original sample was 0.6 µg L(-1). It was verified that Cl(-1) and Ca(2) + influence on tin
absorbance signal is markedly depreciated at concentrations above 100 and 40
mgL(-1), respectively. On the other hand, the increase of tin signal is caused by the
presence of P in concentrations between 5 and 150 mg.L(-1). In a calibration
study, recovery was higher than 95% in human milk. The methodology was able
in determine Sn, as MMT, when iSn is used for the calibration.
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