Determination of arsenic in sediment and soil slurries by electrothermal atomic absorption spectrometry using W–Rh permanent modifier

Abstract

A simple method is described for the determination of As in sediments and soils by electrothermal atomic absorption spectrometry (ETAAS). The procedure combines slurry sampling ETAAS with a 250 μg W + 200 μg Rh permanent chemical modifier. Slurries were sonicated for 20 s before being delivered to the previously W–Rh treated platform. The detection limit for 0.50% m/v slurries was 0.4 μg g⁻¹. The RSD for 783 consecutive measurements of 20 μl of 0.50% m/v soil-5 slurry was 3.8%. In order to verify the accuracy and precision of the proposed method, five sediment and two soil certified reference materials were analysed and the results obtained were in agreement with the certified values.