RESUMO
Results of an inter-laboratory round-robin study of the application of time-resolved emission spectroscopy (TRES) to the speciation of uranium(VI) in aqueous media are presented. The round-robin study involved 13 independent laboratories, using various instrumentation and data analysis methods. Samples were prepared based on appropriate speciation diagrams and, in general, were found to be chemically stable for at least six months. Four different types of aqueous uranyl solutions were studied: (1) acidic medium where UO2(2+)aq is the single emitting species, (2) uranyl in the presence of fluoride ions, (3) uranyl in the presence of sulfate ions, and (4) uranyl in aqueous solutions at different pH, promoting the formation of hydrolyzed species. Results between the laboratories are compared in terms of the number of decay components, luminescence lifetimes, and spectral band positions. The successes and limitations of TRES in uranyl analysis and speciation in aqueous solutions are discussed.
Assuntos
Técnicas de Química Analítica/normas , Laboratórios/normas , Análise Espectral/normas , Urânio , Cooperação Internacional , Controle de Qualidade , Reprodutibilidade dos Testes , Fatores de Tempo , Urânio/análise , Urânio/química , ÁguaRESUMO
We report a case of visceral larva migrans in an adult with fever, night sweats, weight loss, hilar and mediastinal lymphadenopathy, bilateral pleural effusion, and eosinophilia-mimicking lymphoma. Visceral larva migrans was diagnosed subsequently because of negative findings for malignancy and positive serologic test result for Toxocara canis. Progressive improvement was observed with albendazole therapy.
