A sensitive method for cadmium determination using an on-line polyurethane foam preconcentration system and thermospray flame furnace atomic absorption spectrometry

Autor(es)

TARLEY‚ C.R.T. ; ARRUDA‚ M.A.Z.

• Tipo de documento: Artigo Científico
• Fonte: Analytical Sciences; v. 20, n. 6, p. 961-966, 2004.

Resumo

A new sensitive and low cost method for cadmium determination at mug l(-1) levels that combines an on-line preconcentration system with the thermospray flame furnace atomic absorption spectrometry technique (TS-FF-AAS) is described in this work. Cadmium is preconcentrated from an acidic medium (pH 2.0) by forming a complex with ammonium O,O-diethyldithiophosphate (DDTP), which is then adsorbed onto polyurethane foam (PUF). The elution step is performed by using 80% (v/v) ethanol. The effects of the chemical and flow variables associated with the preconcentration were studied, such as the pH of formation of the Cd-DDTP complex, the DDTP concentration, the preconcentration and elution flow rate and the mass of adsorbent. The present method was operated in volume-mode (2 ml) and provided a linear range from 0.4 to 15.0 mug l(-1) with a sample throughput of 16 h(-1). The increase of power detection related to TS-FF-AAS by coupling the preconcentration system was confirmed by the enhancement of sensitivity (ca. 5 times), when compared to the value for TS-FF-AAS alone, thus achieving a low detection limit (0.12 mug l(-1)). The accuracy of the method was confirmed from analyses of spiked water samples and by the use of a reference technique (ETAAS). Certified biological materials were also used for the same purpose. (AU)

• Processo FAPESP: 01/05614-0 - Estudos de adsorção e pré-concentração de metais empregando materiais adsorventes naturais e sintéticos
• Beneficiário: César Ricardo Teixeira Tarley
• 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