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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Determinação dos níveis de estanho em fluidos biológicos de população exposta ambientalmente na Vila Massangana, RO / Determination of levels of tin in biological fluids of environmentally exposed population in the Village Massangana, RO

Azevedo, Sayonara Vieira de January 2009 (has links)
Made available in DSpace on 2011-05-04T12:36:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2009 / O estanho é um elemento natural na crosta terrestre, amplamente utilizado na indústria pelo baixo ponto de fusão, formação de ligas, resistência à corrosão e oxidação. A exposição ao metal e seus compostos pode produzir diversos efeitos nos sistemas neuro,hemato e imunológicos, além de danos ao fígado e rins, entre outros. O objetivo desse trabalho foi a avaliação da exposição ao estanho dos indivíduos residentes na Vila Massangana. Para tal, metodologias para determinação do estanho em sangue e urina foram desenvolvidas (ET AAS). A mesma temperatura ótima de pirólise (1300°C) foi alcançada com ambas as matrizes, enquanto que a de atomização ficou em 2100°C e 2200ºC para sangue e urina, respectivamente. A maior sensibilidade foi alcançada na diluição de 7X para sangue, bem como 5X na urina, ambos diluídos em Triton X-100 0,1 por cento (v/v). (...) / Tin is a natural element in the earth's crust, widely used in industry due to some characteristics like low melting point, production of alloys and resistance to corrosion and oxidation. Exposure to tin metal and its compounds may produce different effects on neural, hemato and immunological systems as well as damage to the liver and kidneys, among others. The aim of this work was the exposure assessment to tin for the population from Vila Massangana. To this end, methodologies for the determination of tin in blood and urine were developed (ET AAS). The same optimum pyrolysis temperature (1300°C) were achieved with both matrices, while the optimum atomization temperature was 2100°C and 2200°C for blood and urine, respectively. The highest sensitivity was achieved in the dilution of 7X for blood and urine 5X, both diluted in 0.1% (v / v) Triton X-100. The efficiency of three different masses of the modifier (Pd and Mg) was studied and the best sensitivity was reached using 10 !g Pd + 6 !g Mg and 15 !g Pd + 10 !g Mg for both matrices. Tin showed linearity up to 50 !g Sn L-1 for curves in blood and urine, which showed the existence of the matrix effects, 0.81 ± 0.06 e 1.32 ± 0.04, respectively. The limit of detection (3") was 0.8 ± 0.1 μg L-1 for urine and 2.7 ± 0.5 μg L-1 for whole blood, which allows the determination of tin in blood and urine of the population not exposed environmentally. The accuracy was verified by analysis of reference materials. For urine, Seronorm Urine (54.6 ± 2.7 μg L- 1) was used and the result was 54.3 ± 1.6, while Contox I Serum (3,0 ± 2 μg L-1) was used for blood, resulting in 2.9 ± 1.2 μg L-1 . After validation, tin concentration was determined in whole blood and urine samples of 22 individuals (blood: 10.5 ± 1.7 μg L- 1, urine: 3.2 ± 1.1 μg L-1) living in Vila Massangana and 11 people (blood: 8.4 ± 1.2 μg L-1; urine: 1.0 ± 0.5 μg L-1) in the control group. There was a statistically significant difference (p <0.05) between these two groups, showing the existence of environmental exposure. There was a statistically significant difference (p <0.05) between these two groups, showing the existence of environmental exposure.

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