Bibliogr. s. 150.

Determination of silver traces in the presence of copper, zinc and sulphate ions by a catalytic method was studied. The highly sensitive method of silver determination is based on the catalytic effect of silver ions on the oxidation of salicylic acid by persulphate in the presence of 2,2'-dipyridyl as an activator. The reaction was followed spectrophotometrically by measuring the rate of change in absorbance with time at 420 nm after 10 min of reagents mixing. The sensitivity, precision and accuracy of the determination of silver traces were investigated in solutions containing excesses of interfering ions. The studied range of interfering ions concentrations was 8 × 10–6 to 2.4 × 10–2 mol dm–3 and corresponds to an amount ratio of interfering to silver ions from 50 to 150 000. The performed analyses showed that the accuracy and precision of silver trace determination by the proposed method is high even in the presence of a huge amount excess of interfering ions. The method was used for quantitative determination of silver contents in a copper foil and in a zinc rod. The obtained results were compared with the analyses performed by FAAS.