The determination of As by hydride generation atomic absorption spectroscopy (HG-AAS) is a simple, sensitive, precise and low-cost method. However, this technique requires the pre-reduction of the existing As(V) species, which is obtained by the use of reducing agents such as KI. In extracts containing oxidizing agents, the pre-reduction of As is impaired, as it occurs in extracts obtained by the BCR (French acronym for Community Bureau of Reference) method for the sequential extraction of As in sediments. The objective of this study was to evaluate the conditions for the reduction of As(V) to As(III) in a way that allows the use of HG-AAS for the quantification of arsenic in extracts obtained using the BCR method. Reaction conditions were evaluated using KI, L-Cysteine and ascorbic acid. For each of the BCR extraction steps, different conditions of pre-reduction enabled the quantitative detection of As. The use of the BCR method for the extraction of arsenic from contaminated sediment samples and the application of pre-reduction conditions of the As(V) followed by HG-AAS detection resulted in relative recoveries between 91 and 99 %.
arsenic; sequential extraction; hydride generation atomic absorption spectroscopy; sediments
