Determinação de As, Cd e Pb em amêndoas e mesocarpo de babaçu, sapucaia, xixá e castanha-do-pará por espectrometria de absorção atômica

Abstract

Recebido em 14/6/08; aceito em 9/2/09; publicado na web em 14/7/09 DETERMINATION OF As, Cd AND Pb IN BABASSU NUT AND MESOCARP, SAPUCAIA, XIXA AND BRAZILIAN NUT BY ATOMIC ABSORPTION SPECTROMETRY. This work describes methods for the simultaneous determination of Cd and Pb by graphite furnace atomic absorption spectrometry and As by hydride generation atomic absorption spectrometry in Brazilian nuts. The samples (~ 0.300 g) were digested to clear solutions in a closed vessel microwave oven. The pyrolysis and atomization temperatures for simultaneous determinations of Cd and Pb were 1100 and 2100 °C, respectively, using 0.5% (w v-1) NH 4 H 2 PO 4 + 0.03% (w v-1) Mg(NO 3) 2 as chemical modifier. The limits of detection (3δ) were 3.8 µg kg-1 for As, 0.86 µg kg-1 for Cd and 13 µg kg-1 for Pb. The reliability of the entire procedures was confirmed by peach leaves (No. 1547-NIST) certified reference material analysis and addition and recovery tests. The found concentrations presented no statistical differences at the 95% confidence level.