Speciation of Arsenic in Environmental Samples of the Nha Trang Harbor,Vietnam, Using HPLC Coupled HG-AAS

A coupled High Performance Liquid Chromatography – Hydride Generation-Atomic Absorption Spectroscopy system was used to determine the speciation of Arsenic in samples from the Nha Trang Harbor, Vietnam. Concentrations of Arsenic in seawater, pore water, suspended solid, and sediment were 4.12–9.81 μg/L, 13.10–24.32 μg/L, 1.87–6.42 μg/g, and 3.37–9.06 μg/g, respectively. Extraction using H₃PO₄ + NH₂OH·HCl and ultrasonic digestion was optimized to yield a 76–85% of total Arsenic. Arsenic (III) was the most abundant species in suspended solids and sediments whereas Arsenic (V) represented for 30–50% of Arsenic (III) concentration. Monomethylarsonic acid and Dimethylarsinic acid species were undetectable.