Characterization of Arsenic in Sea Water by Hydride Generation-Atomic Absorption Spectrometry

Abstract

A simple digestion procedure with potassium persulfate in alkaline medium is described for the determination of the total concentration of arsenic species in sea water. Combined with the previously proposed method for the differential determination of As(III) and As(V) by hydride generation-atomic absorption spectrometry, arsenic species in sea water were determined as As(III), As(V) and organoarsenic species. Sub ppb level of arsenic in sea water could be detected with a sample volume of 100ml. In sea water samples of the Japan Sea and the northwestern North Pacific Ocean, an average of total concentrations of arsenic was found to be about 2.0μg l-1 irrespective of locality. Total concentrations were rather constant from surface to deep water. As(III) and organic species were found only in surface water and the concentration of As(V) was about 0.2 to 0.3μg l-1 lower in the surface water than in the deep water.