This aim of this work was to compare two methods for copper determination in insulating oils from power transformers by GFAAS. The first method was extraction induced by emulsion breaking, which determined the preconcentration of copper in an aqueous solution and exhibited a limit of quantification of 0.27 µg L-1. Also, a second method based on the direct introduction of samples into GFAAS in the form of detergent emulsions, prepared with Triton X-114 and HNO3, was investigated. In this case, the limit of quantification was 1.7 µg L-1. Seven samples of used oils were successfully analyzed by both methods.

This paper reports the evaluation of extraction strategies for the treatment of medicine samples to determine chromium and nickel by GFAAS. Different approaches for extraction were evaluated and the most efficient involved magnetic stirring. The metals were quantitatively extracted by stirring 0.20 g samples with 25 mL of 2.0 mol L-1 HCl solution for 60 min. The developed method was successfully applied for the determination of Cr and Ni in tablets containing antibiotics and raw materials, with cephalexin and ciprofloxacin as active ingredients.

A distribuição de compostos aromáticos selecionados e a microbiologia foram avaliados em sedimentos superficiais do Manguezal de Suruí, Baía de Guanabara. Amostras foram coletadas em 23 pontos e determinados a granulometria, matéria orgânica, compostos aromáticos, atividade microbiológica, biopolímeros e a topografia. A concentração dos compostos aromáticos foi distribuída em manchas por todo o manguezal e sua concentração total mais elevada foi encontrada na área central do manguezal. A granulometria diferiu da maioria dos manguezais, uma vez que no Manguezal de Suruí existem chernies nas bordas e na frente dos manguezais e areia através da superfície inteira, impedindo o relacionamento entre granulometria e os hidrocarbonetos. Uma média de 10% p/p da matéria orgânica foi obtida e os biopolímeros apresentaram concentrações elevadas, especialmente na área central e fundo do Manguezal. Os biopolímeros se distribuíram em altas concentrações. A presença de finos sedimentos é fator importante na acumulação de hidrocarbonetos. Na concentração elevada de matéria orgânica e de biopolímeros, topografia com chernies e as raízes que protegem os manguezais, áreas mais calmas são criadas, com depósito do material transportado pela ação das ondas. Comparadas às distribuições globais, as concentrações das substâncias aromáticas neste manguezal podem ser classificadas de moderadas a elevadas, demonstrando que a área estudada está altamente impactada.

The distribution of selected aromatic compounds and microbiology were assessed in superficial sediments from Suruí Mangrove, Guanabara Bay. Samples were collected at 23 stations, and particle size, organic matter, aromatic compounds, microbiology activity, biopolymers, and topography were determined. The concentration of aromatic compounds was distributed in patches over the entire mangrove, and their highest total concentration was determinated in the mangrove's central area. Particle size differed from most mangroves in that Suruí Mangrove has chernies on the edges and in front of the mangrove, and sand across the whole surface, which hampers the relationship between particle size and hydrocarbons. An average @ 10% p/p of organic matter was obtained, and biopolymers presented high concentrations, especially in the central and back areas of the mangrove. The biopolymers were distributed in high concentrations. The presence of fine sediments is an important factor in hydrocarbon accumulation. With high concentration of organic matter and biopolymers, and the topography with chernies and roots protecting the mangrove, calmer areas are created with the deposition of material transported by wave action. Compared to global distributions, concentrations of aromatic compounds in Suruí Mangrove may be classified from moderate to high, showing that the studied area is highly impacted.