Phase composition of anodic film formed on an lead electrode at 1.3 V (vs. Hg/Hg2SO4) for 30 min in 4.5 mol dm-3 H2SO4(30? was determine by linear sweep voltammetry followed by open-circuit decay curve method. The latter is carried out after the potential is swept forward around certain peak potential in the voltammogram. The electrochem. method is compared with other methods, i.e., in situ x-ray diffractometry, atomic absorption spectrophotometry, and anodic stripping voltammetry. The peak potential in the voltammogram and the steady state potential in the open-circuit curve can be used to determine the phase composition qual., while the peak area in the voltammogram can be used to determine the amount of the phase component. The anodic films formed in this work are composed of PbO.PbSO4, PbO2, and PbOn (2 > n > 1), with the first one as the major constituent.

Key words: POLYETHYLENE, ATOMIC ABSORPTION SPECTROPHOTOMETRY, SULFURIC ACID, X-RAY DIFFRACTION ANALYSIS, LEAD, MEMBRANE ELECTRODES, PHASE, ANODES, ELECTROCHEMICAL ANALYSIS, ELECTRODE POTENTIAL