Desenvolvimento de métodos em espectrometria de emissão óptica com plasma induzido por laser (LIBS) para determinação de Cd, Cr e Pb em tecidos animais

• Ano de defesa: 2014
• Autor(a) principal: Abe, Claudia Naomi [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo
• Palavras-chave em Português: Optical emission spectroscopy; LIBS; Laser; Toxic elements; Animal tissue; Espectrometria de emissão óptica; Elementos tóxicos; Tecido animal
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=1612371; http://repositorio.unifesp.br/handle/11600/47470

Laser-Induced Breakdown Spectroscopy (LIBS) has been considered a very promising analytical technique for applications in quality control, materials chemistry, environmental toxicology, forensic chemistry, biomedicine, among others. In this work, it was evaluated the LIBS technique for the determination of Cd, Cr, and Pb in bovine muscle, bovine liver, bovine kidney, fish muscle, mussel, and shrimp. The experimental setup was designed by using a Q-switched Nd:YAG laser at 1064 nm (5 ns, 10 Hz) and the emission signals were collected by lenses into an optical fiber coupled to an Echelle spectrometer equipped with an intensified charge-coupled device (ICCD). The effects of delay time in analytical signal collection, as well as the effect of integration time, laser fluence, sampling diameter, and number of accumulated laser pulses were evaluated. Best results were obtained when the samples were analyzed by using with laser fluence of 35 J cm?2 (1050 µm spot size), 2.0 µs of gate delay, 5,0 µs of integration time and 25 laser pulses. It was observed that the ablation of fresh tissue samples must be evaluated with higher laser energy due to the moisture content of these samples. The results obtained from the pellets analysis indicated the viability of the LIBS technique for determination of Cd, Cr, and Pb in animal tissues, but the limit of detection of Pb, 10µg/g, , must be improved for evaluations in the biomedical area.