Differential-pulse voltammetric determination of total arsenic following its volatilization as AsH3 and absorption in silver nitrate solution

Abstract

A procedure is described for the volatilization of inorganic arsenic(III) and arsenic(V) as AsH₃ and the absorption of AsH₃ in a silver nitrate solution. For the absorption of AsH₃, a specially designed glass cell has been used which cycles the absorption solution, utilizing the principle of a mammouth pump. In the adsorption solution, arsenic(III) is determined by differential-pulse voltammetry. The procedure is applicable in the concentration range from 1 × 10^–6 to 5 × 10^–5 mol l^–1.