Analysis of arsenic(V) by cathodic stripping voltammetry

A novel electrochemical stripping approach is presented for the trace measurement of arsenate. It is based on the reduction of As(V) in a mannitol and perchlorate containing solution, the coprecipitation with copper and the voltammetric determination by further reduction to AsH3 at the hanging mercury drop electrode. For an accumulation period of 60 s, the detection limit has been found to be 4.4 μg1; the determination limit was calculated to be 11 μg1. The method has been applied to the analysis of arsenic in a standard stream sediment and in water samples.