Croatica Chemica Acta, Vol. 80 No. 1, 2007.
Short communication, Note
Determination of Silver Traces in Pure Metallic Copper and Zinc by a Catalytic Photometric Method
Grzegorz D. Sulka
Marian Jaskula
Abstract
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.
Keywords
silver traces; kinetics based analytical methods; copper ion interference; zinc ion interference; sulphate ion interference
Hrčak ID:
12837
URI
Publication date:
11.3.2007.
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