Evaluation of zirconium as a permanent chemical modifier using synchrotron radiation and imaging techniques for lithium determination in sediment slurry samples by ET AAS

Autor(es)

Flores‚ A.V. ; Pérez‚ C.A. ; Arruda‚ M.A.Z.

• Tipo de documento: Artigo Científico
• Fonte: Talanta; v. 62, n. 3, p. 619-626, 2004.

Resumo

In the present paper, lithium was determined in river sediment using slurry sampling and electrothermal atomic absorption spectrometry (ET AAS) after L'vov platform coating with zirconium (as a permanent chemical modifier). The performance of this modifier and its distribution on the L'vov platform after different heating cycles were evaluated using synchrotron radiation X-ray fluorescence (SRXRF) and imaging scanning electron microscopy (SEM) techniques. The analytical conditions for lithium determination in river sediment slurries were also investigated and the best conditions were obtained employing 1300 and 2300degreesC for pyrolysis and atomization temperatures, respectively. In addition, 100 mg of sediment samples were prepared using 4.0 mol l(-1) HNO3. The Zr-coating permitted lithium determination with good precision and accuracy after 480 heating cycles using the same platform for slurry samples. The sediment samples were collected from five different points of the Cachoeira river, S (a) over tildeo Paulo, Brazil. The detection and quantification limits were, respectively, 0.07 and 0.23 mug l(-1). (C) 2003 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 00/09289-3 - Emprego da amostragem de suspensão para a determinação de Sc e Li em sedimento de rio por ETAAS
• Beneficiário: Araceli Veronica Flores
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 99/12124-7 - Emprego de novos materiais e diferentes ambientes reacionais para melhoria em sensibilidade e seletividade na análise de amostras biológicas e ambientais
• Beneficiário: Elias Ayres Guidetti Zagatto
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 03/00674-0 - Mapeamento e quantificacao de ions metalicos ligados a proteinas empregando radiacao sincrotron e espectrometria atomica apos separacao por eletroforese em gel.
• Beneficiário: Marco Aurelio Zezzi Arruda
• Modalidade de apoio: Auxílio à Pesquisa - Regular