engleski

Pseudopolarography of trace metals. Part 1. The automatic ASV measurements of reversible electrode reactions

The main advantage of the automated computer- controlled pseudopolarographic measurements is a possibility of their practical application to the determination of trace metals speciation. This paper describes the pseudopolarographic characteristics of the reversible electrochemical reactions of dissolved trace metals, such as: lead(II), thallium(I) and bismuth(III), in the model electrolytes, at the metal concentrations of about 10^-7 mol L^-1, on a stationary mercury drop electrode (SMDE), using a differential pulse anodic stripping voltammetry (DPASV) technique. There is a good agreement between the formal potential determined by the sampled d.c. polarography (10^-4 mol L^-1) and pseudopolarography (10^-7 mol L^-1). The half-wave potential of the pseudopolarograms shifts with the accumulation time but remains unaffected by the increase of the metal concentration in the solution, which is in a good agreement with the theoretical suppositions. The dependence of the shape of the pseudopolarogram on the method used for the determination of the anodic peak current, is presented. The development and the application of the efficient mathematical treatment of the experimental (pseudo)polarographic data for the determination of the half-wave potential, the transfer coefficient, the rate constant, etc., are presented.

anodic stripping voltammetry ; automation ; data simulation ; data treatment ; polarography ; pseudopolarography ; speciation ; trace metals

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