Magda Beretta

Distribuição espacial de compostos orgânicos de estanho em sedimentos costeiros e em Phallusia nigra da Baía de Todos os Santos e litoral norte da Bahia - Brasil

Organic tin compounds were investigated in the sediment of twenty-four stations located in the Todos os Santos Bay and the north coast of Bahia - Brazil. The concentration of these organic tin was also determined in a ascidium species of Phallusia nigra. The speciation and quantification was performed by GC-MS/MS. The highest concentrations were: tributyltin (TBT) 438 ng g-1, dibutyltin (DBT) 207 ng g-1, monobutyltin (MBT) 423 ng g-1, diphenyltin (DPT) 25.8 ng g-1 and monophenyltin (MPT) 55.0 ng g-1. DBT and MBT were found in Phallusia nigra, with highest concentrations of 294.1 and 148.5 ng g-1, respectively.

Quantification and toxicity testing of pharmaceuticals in tropical marine sediments, All Saints Bay, Bahia, Brazil

The presence and effects of pharmaceuticals in the environment have gained increased attention lately because of their widespread use and their potential to bioaccumulate and induce negative effects in aquatic and terrestrial ecosystems. This work presents the quantification of pharmaceutical compounds in sediments of All Saints Bay, Bahia, Brazil and toxicity testing of the compounds Atenolol, Erythromycin and Caffeine on sediment microorganisms and microcrustaceans (Artemia salina). Pharmaceuticals were shown to be widely distributed in sediments of All Saints Bay, in areas near the capital Salvador as well as in more remote areas of the bay. Toxicity tests revealed a susceptibility of microorganisms and microcrustaceans to both Erythromycin and Caffeine at higher concentrations, while Atenolol did not cause toxic effects. The presence of pharmaceuticals at the levels detected did not imply acute toxicity to microorganisms and microcrustaceans.

Craqueamento térmico de alcanos: uma aula prática de química orgânica para a graduação

In this work we describe an experiment for the thermal cracking of octane and heptane and the qualitative analyses of the products using the Baeyer test for unsaturated compounds and gas chromatographic analyses. The experiment is very simple and requires one period of two hours and is suitable for undergraduate organic chemistry experimental courses.