Hydride generation atomic absorption determination of arsenic in marine sediments, tissues and sea water with in situ concentration in a graphite furnace

Abstract

Methods are described for the determination of total As in sea water and in marine tissues and sediments based on the generation of AsH₃ using NaBH₄ with its subsequent trapping in a graphite furnace at 600 °C. Calibration is achieved with a simple aqueous calibration graph having a sensitivity of 0.18 ± 0.03 A ng^–1 and yields an absolute detection limit of 40 pg. Sample volumes of 10–500 µl produce total method concentration detection limits (3σ blank) of 60 pg g^–1 in sea water, 0.2 µg g^–1 in sediments and 0.15 µg g^–1 in tissues. Corresponding precisions of 2–3% are typical for analyses of these samples. Results are reported for the determination of As in a suite of marine reference materials.