Evaluation of a synergetic effect between Rh as permanent chemical modifier and acetylacetone as complexing agent in Sc determination in sediment slurry samples by ETAAS

Autor(es)

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

• Tipo de documento: Artigo Científico
• Fonte: Analytica Chimica Acta; v. 530, n. 2, p. 299-305, 2005.

Resumo

In the present work, scandium was determined in sediment slurry samples (from three different rivers) by electrothermal atomic absorption spectrometry (ETAAS). Slurries were prepared by weighting 100 mg of dry sediment samples (less than or equal to53 mum particle sizes) and adding 6 ml of HCI:HNO3:HF (3:1:2, v/v). Accurate results were only possible due to the synergetic effect between Rh as permanent chemical modifier and acetylacetone (Acac) as complexing agent. The same platforrn was used for 400 heating cycles. The performance of the chemical modification was evaluated by using scanning electron microscopy (SEM), synchrotron radiation X-ray fluorescence (SRXRF) and some figures of merit (precision and delectability). The best analytical conditions were attained using 1500 and 2550degreesC as pyrolysis and atomization temperatures. The scandium content in the liquid phase of the slurries ranged from 61 to 73%, thus indicating, in this study, that both liquid and solid phases play an important role in slurry analyses. An amount of 5.0-20.0 [mug 1(-1) Sc linear range as well as LOD and LOQ of 0.19 and 0.62 mug 1(-1) respectively, were obtained under these conditions. The accuracy was checked by using microwave-assisted decomposition, and the results compared to those obtained with the proposed methodology (slurry analysis). By checking both sets of the results, there is no statistical difference at the 95% confidence levels. (C) 2004 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